Standards of Medical Care in Diabetes—2021 Abridged for Primary Care Providers

The American Diabetes Association (ADA) Standards of Medical Care in Diabetes is updated and published annually in a supplement to the January issue of Diabetes Care. The Standards are developed by the ADA’s multidisciplinary Professional Practice Committee, which comprises physicians, diabetes educators, and other expert diabetes health care professionals. The Standards include the most current evidence-based recommendations for diagnosing and treating adults and children with all forms of diabetes. ADA’s grading system uses A, B, C, or E to show the evidence level that supports each recommendation.

This is an abridged version of the current Standards containing the evidence-based recommendations most pertinent to primary care. The recommendations tables and figures included here retain the same numbering used in the full Standards and so are not numbered sequentially. All of the recommendations included here are substantively the same as in the full Standards. The abridged version does not include references. The complete 2021 Standards of Care, including all supporting references, is available at professional.diabetes.org/standards.

1. Improving Care and Promoting Health in Populations

Diabetes and Population Health

Clinical practice recommendations can improve health across populations; however, for optimal outcomes, diabetes care must also be individualized for each patient. Thus, efforts to improve population health will require a combination of policy-level, system-level, and patient-level approaches. Patient-centered care is defined as care that considers individual patient comorbidities and prognoses; is respectful of and responsive to patient preferences, needs, and values; and ensures that patient values guide all clinical decisions. Further, social determinants of health (SDOH)—often out of direct control of the individual and potentially representing lifelong risk—contribute to medical and psychosocial outcomes and must be addressed to improve all health outcomes.

Recommendations

Six Core Elements

The CCM includes six core elements to optimize the care of patients with chronic disease:

Strategies for System-Level Improvement

Care Teams

Collaborative, multidisciplinary teams are best suited to provide care for people with chronic conditions such as diabetes and to facilitate patients’ self-management. The care team should avoid therapeutic inertia and prioritize timely and appropriate intensification of lifestyle and/or pharmacologic therapy for patients who have not achieved the recommended metabolic targets.

Telemedicine

Telemedicine is a growing field that may increase access to care for patients with diabetes. Increasingly, evidence suggests that various telemedicine modalities may be effective at reducing A1C in patients with type 2 diabetes compared with usual care or in addition to usual care.

Behaviors and Well-Being

Successful diabetes care also requires a systematic approach to supporting patients’ behavior-change efforts, including high-quality diabetes self-management education and support (DSMES).

Tailoring Treatment for Social Context

Recommendations

Health inequities related to diabetes and its complications are well documented and have been associated with greater risk for diabetes, higher population prevalence, and poorer diabetes outcomes. SDOH are defined as the economic, environmental, political, and social conditions in which people live and are responsible for a major part of health inequality worldwide.

2. Classification and Diagnosis of Diabetes

Classification

Diabetes can be classified into the following general categories:

It is important for providers to realize that classification of diabetes type is not always straightforward at presentation, and misdiagnosis may occur. ​ Children with type 1 diabetes typically present with polyuria/polydipsia, and approximately one-third present with diabetic ketoacidosis (DKA). Adults with type 1 diabetes may not present with classic symptoms and may have a temporary remission from the need for insulin. The diagnosis may become more obvious over time and should be reevaluated if there is concern.

Screening and Diagnostic Tests for Prediabetes and Type 2 Diabetes

The diagnostic criteria for diabetes and prediabetes are shown in Table 2.2/2.5. Screening criteria are listed in Table 2.3.

TABLE 2.2/2.5

Criteria for the Screening and Diagnosis of Prediabetes and Diabetes

. Prediabetes . Diabetes .
A1C 5.7–6.4% (39–47 mmol/mol)* ≥6.5% (48 mmol/mol)†
Fasting plasma glucose 100–125 mg/dL (5.6–6.9 mmol/L)* ≥126 mg/dL (7.0 mmol/L)†
2-hour plasma glucose during 75-g OGTT 140–199 mg/dL (7.8–11.0 mmol/L)* ≥200 mg/dL (11.1 mmol/L)†
Random plasma glucose ≥200 mg/dL (11.1 mmol/L)‡
. Prediabetes . Diabetes .
A1C 5.7–6.4% (39–47 mmol/mol)* ≥6.5% (48 mmol/mol)†
Fasting plasma glucose 100–125 mg/dL (5.6–6.9 mmol/L)* ≥126 mg/dL (7.0 mmol/L)†
2-hour plasma glucose during 75-g OGTT 140–199 mg/dL (7.8–11.0 mmol/L)* ≥200 mg/dL (11.1 mmol/L)†
Random plasma glucose ≥200 mg/dL (11.1 mmol/L)‡

Adapted from Tables 2.2 and 2.5 in the complete 2021 Standards of Care. *For all three tests, risk is continuous, extending below the lower limit of the range and becoming disproportionately greater at the higher end of the range. †In the absence of unequivocal hyperglycemia, diagnosis requires two abnormal test results from the same sample or in two separate samples ‡Only diagnostic in a patient with classic symptoms of hyperglycemia or hyperglycemic crisis. OGTT, oral glucose tolerance test.

Criteria for Testing for Diabetes or Prediabetes in Asymptomatic Adults

1. Testing should be considered in adults with overweight or obesity (BMI ≥25 kg/m 2 or ≥23 kg/m 2 in Asian Americans) who have one or more of the following risk factors:
• First-degree relative with diabetes
• High-risk race/ethnicity (e.g., African American, Latino, Native American, Asian American, Pacific Islander)
• History of CVD
• Hypertension (≥140/90 mmHg or on therapy for hypertension)
• HDL cholesterol level 250 mg/dL (2.82 mmol/L)
• Women with polycystic ovary syndrome
• Physical inactivity
• Other clinical conditions associated with insulin resistance (e.g., severe obesity, acanthosis nigricans)
2. Patients with prediabetes (A1C ≥5.7% [39 mmol/mol], impaired glucose tolerance, or impaired fasting glucose) should be tested yearly.
3. Women who were diagnosed with GDM should have lifelong testing at least every 3 years.
4. For all other patients, testing should begin at age 45 years.
5. If results are normal, testing should be repeated at a minimum of 3-year intervals, with consideration of more frequent testing depending on initial results and risk status.
6. HIV
1. Testing should be considered in adults with overweight or obesity (BMI ≥25 kg/m 2 or ≥23 kg/m 2 in Asian Americans) who have one or more of the following risk factors:
• First-degree relative with diabetes
• High-risk race/ethnicity (e.g., African American, Latino, Native American, Asian American, Pacific Islander)
• History of CVD
• Hypertension (≥140/90 mmHg or on therapy for hypertension)
• HDL cholesterol level 250 mg/dL (2.82 mmol/L)
• Women with polycystic ovary syndrome
• Physical inactivity
• Other clinical conditions associated with insulin resistance (e.g., severe obesity, acanthosis nigricans)
2. Patients with prediabetes (A1C ≥5.7% [39 mmol/mol], impaired glucose tolerance, or impaired fasting glucose) should be tested yearly.
3. Women who were diagnosed with GDM should have lifelong testing at least every 3 years.
4. For all other patients, testing should begin at age 45 years.
5. If results are normal, testing should be repeated at a minimum of 3-year intervals, with consideration of more frequent testing depending on initial results and risk status.
6. HIV

Recommendations

Risk-Based Screening for Type 2 Diabetes or Prediabetes in Asymptomatic Children and Adolescents in a Clinical Setting

.
Testing should be considered in youth* who have overweight (≥85th percentile) or obesity (≥95th percentile) A and who have one or more additional risk factors based on the strength of their association with diabetes:
• Maternal history of diabetes or GDM during the child’s gestation A
Family history of type 2 diabetes in first- or second-degree relative A
• Race/ethnicity (Native American, African American, Latino, Asian American, Pacific Islander) A
• Signs of insulin resistance or conditions associated with insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, polycystic ovary syndrome, or small-for-gestational-age birth weight) B
.
Testing should be considered in youth* who have overweight (≥85th percentile) or obesity (≥95th percentile) A and who have one or more additional risk factors based on the strength of their association with diabetes:
• Maternal history of diabetes or GDM during the child’s gestation A
Family history of type 2 diabetes in first- or second-degree relative A
• Race/ethnicity (Native American, African American, Latino, Asian American, Pacific Islander) A
• Signs of insulin resistance or conditions associated with insulin resistance (acanthosis nigricans, hypertension, dyslipidemia, polycystic ovary syndrome, or small-for-gestational-age birth weight) B

After the onset of puberty or after 10 years of age, whichever occurs earlier. If tests are normal, repeat testing at a minimum of 3-year intervals (or more frequently if BMI is increasing or risk factor profile deteriorating) is recommended. Reports of type 2 diabetes before age 10 years exist, and this can be considered with numerous risk factors.

An assessment tool such as the ADA risk test (diabetes.org/socrisktest) is recommended to guide providers on whether performing a diagnostic test for prediabetes or previously undiagnosed type 2 diabetes is appropriate.

Marked discrepancies between measured A1C and plasma glucose levels should prompt consideration that the A1C assay may not be reliable for that individual, and one should consider using an A1C assay without interference or plasma blood glucose criteria for diagnosis. (An updated list of A1C assays with interferences is available at ngsp.org/interf.asp.) Unless there is a clear clinical diagnosis based on overt signs of hyperglycemia, diagnosis requires two abnormal test results from the same sample or in two separate test samples. If using two separate test samples, it is recommended that the second test, which may either be a repeat of the initial test or a different test, be performed without delay. If the patient has a test result near the margins of the diagnostic threshold, the provider should follow the patient closely and repeat the test in 3–6 months.

Certain medications, such as glucocorticoids, thiazide diuretics, some HIV medications, and atypical antipsychotics, are known to increase the risk of diabetes and should be considered when deciding whether to screen.

3. Prevention or Delay of Type 2 Diabetes

Recommendation

Lifestyle Behavior Change for Diabetes Prevention

Recommendations

Delivery and Dissemination of Lifestyle Behavior Change for Diabetes Prevention

The DPP research trial demonstrated that an intensive lifestyle intervention could reduce the risk of incident type 2 diabetes by 58% over 3 years. The Centers for Disease Control and Prevention (CDC) developed the National Diabetes Prevention Program (National DPP), a resource designed to bring such evidence-based lifestyle change programs for preventing type 2 diabetes to communities (cdc.gov/diabetes/prevention).

The Centers for Medicare & Medicaid Services has expanded Medicare reimbursement coverage for the National DPP lifestyle intervention to organizations recognized by the CDC that become Medicare suppliers for this service. The locations of Medicare DPPs are available online at innovation.cms.gov/innovation-models/medicare-diabetes-prevention-program/mdpp-map.

To qualify for Medicare coverage, patients must have a BMI in the overweight range and laboratory testing consistent with prediabetes in the last year. Medicaid coverage of the DPP lifestyle intervention is also expanding on a state-by-state basis.

Pharmacologic Interventions

Recommendation

Metformin has the strongest evidence base and demonstrated long-term safety as a pharmacologic therapy for diabetes prevention. Other medications have been studied; no pharmacologic agent has been approved by the U.S. Food and Drug Administration (FDA) specifically for diabetes prevention.

Prevention of Vascular Disease and Mortality

Recommendation

4. Comprehensive Medical Evaluation and Assessment of Comorbidities

Patient-Centered Collaborative Care

A successful medical evaluation depends on beneficial interactions between the patient and a coordinated interdisciplinary team. Individuals with diabetes must assume an active role in their care. The patient, family or support people, physicians, and health care team should together formulate the management plan, which includes lifestyle management.

The goals of treatment for diabetes are to prevent or delay complications and optimize quality of life (Figure 4.1). Treatment goals and plans should be created with patients based on their individual preferences, values, and goals.

FIGURE 4.1. Decision cycle for patient-centered glycemic management in type 2 diabetes. HbA1c, glycated hemoglobin. Reprinted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Decision cycle for patient-centered glycemic management in type 2 diabetes. HbA1c, glycated hemoglobin. Reprinted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

FIGURE 4.1. Decision cycle for patient-centered glycemic management in type 2 diabetes. HbA1c, glycated hemoglobin. Reprinted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Decision cycle for patient-centered glycemic management in type 2 diabetes. HbA1c, glycated hemoglobin. Reprinted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Recommendations

The use of empowering language can help to inform and motivate people, yet language that shames and judges may undermine this effort.

Comprehensive Medical Evaluation

Recommendations

Immunizations

The importance of routine vaccinations for people living with diabetes has been elevated by the coronavirus disease 2019 (COVID-19) pandemic. Preventing avoidable infections not only directly prevents morbidity but also reduces hospitalizations, which may additionally reduce risk of acquiring infections such as COVID-19. Children and adults with diabetes should receive vaccinations according to age-appropriate recommendations.

Assessment of Comorbidities

Cognitive Impairment/Dementia

See “12. OLDER ADULTS.”

Nonalcoholic Fatty Liver Disease

Recommendation

Cancer

Patients with diabetes should be encouraged to undergo recommended age- and sex-appropriate cancer screenings and to reduce their modifiable cancer risk factors (obesity, physical inactivity, and smoking).

5. Facilitating Behavior Change and Well-Being to Improve Health Outcomes

Effective behavior management and psychological well-being are foundational to achieving treatment goals for people with diabetes. Essential to achieving these goals are DSMES, medical nutrition therapy (MNT), routine physical activity, smoking cessation counseling when needed, and psychosocial care.

DSMES

Recommendations

Evidence suggests people with diabetes who completed more than 10 hours of DSMES over the course of 6–12 months and those who participated on an ongoing basis had significant reductions in mortality and A1C (decrease of 0.57%) compared with those who spent less time with a CDCES.

DSMES is associated with an increased use of primary care and preventive services and less frequent use of acute care and inpatient hospital services. Patients who participate in DSMES are more likely to follow best practice treatment recommendations, particularly among the Medicare population, and have lower Medicare and insurance claim costs.

MNT

All providers should refer people with diabetes for individualized MNT provided by a registered dietitian nutritionist (RD/RDN) who is knowledgeable and skilled in providing diabetes-specific MNT at diagnosis and as needed throughout the life span, similar to DSMES. MNT delivered by an RD/RDN is associated with A1C absolute decreases of 1.0–1.9% for people with type 1 diabetes and 0.32.0% for people with type 2 diabetes.

Eating Patterns and Meal Planning

Evidence suggests that there is not an ideal percentage of calories from carbohydrate, protein, and fat for people with diabetes. Therefore, macronutrient distribution should be based on an individualized assessment of current eating patterns, personal preferences (e.g., tradition, culture, religion, health beliefs and goals, and economics), and metabolic goals.

Weight Management

Lifestyle intervention programs should be intensive and have frequent follow-up to achieve significant reductions in excess body weight and improve clinical indicators.

For many individuals with overweight and obesity with type 2 diabetes, 5% weight loss is needed to achieve beneficial outcomes in glycemic control, lipids, and blood pressure. The clinical benefits of weight loss are progressive, and more intensive weight-loss goals (i.e., 15%) may be appropriate to maximize benefit depending on need, feasibility, and safety.

Physical Activity

Recommendations

Exercise in the Presence of Microvascular Complications

Retinopathy

If proliferative diabetic retinopathy or severe nonproliferative diabetic retinopathy is present, then vigorous-intensity aerobic or resistance exercise may be contraindicated because of the risk of triggering vitreous hemorrhage or retinal detachment. Consultation with an ophthalmologist prior to engaging in an intense exercise regimen may be appropriate.

Peripheral Neuropathy

Decreased pain sensation and a higher pain threshold in the extremities can result in an increased risk of skin breakdown, infection, and Charcot joint destruction with some forms of exercise. All individuals with peripheral neuropathy should wear proper footwear and examine their feet daily to detect lesions early. Anyone with a foot injury or open sore should be restricted to non–weight-bearing activities.

Autonomic Neuropathy

Individuals with diabetic autonomic neuropathy should undergo cardiac investigation before beginning physical activity more intense than that to which they are accustomed.

Diabetic Kidney Disease

Physical activity can acutely increase urinary albumin excretion. However, there is no evidence that vigorous-intensity exercise accelerates the rate of progression of diabetic kidney disease (DKD), and there appears to be no need for specific exercise restrictions for people with DKD in general.

Smoking Cessation: Tobacco and E-Cigarettes

Recommendations

Psychosocial Issues

Recommendations

Diabetes Distress

Recommendation

Diabetes distress refers to significant negative psychological reactions related to emotional burdens and worries specific to an individual's experience in having to manage a severe, complicated, and demanding chronic disease such as diabetes. The constant behavioral demands of diabetes self-management and the potential or actuality of disease progression are directly associated with reports of diabetes distress.

See “5. Facilitating Behavior Change and Well-Being to Improve Health Outcomes” in the complete 2021 Standards of Care for information on anxiety disorders (including fear of hypoglycemia), depression, disordered eating, and serious mental illness, as well as information about referral to a mental health professional.

6. Glycemic Targets

Assessment of Glycemic Control

Glycemic control is assessed by the A1C measurement, continuous glucose monitoring (CGM), and self-monitoring of blood glucose (SMBG). Clinical trials primarily use A1C as the metric to demonstrate the benefits of improved glycemic control. CGM serves an important role in assessing the effectiveness and safety of treatment in many patients with type 1 diabetes, including prevention of hypoglycemia, and in patients with type 2 diabetes on intensive insulin regimens and with hypoglycemia. Patient SMBG can be used with self-management and medication adjustment, particularly in individuals taking insulin.

Glycemic Assessment

Recommendations

Glucose Assessment by CGM

Recommendations

For many people with diabetes, glucose monitoring is key for achieving glycemic targets. It allows patients to evaluate their individual response to therapy and assess whether glycemic targets are being safely achieved.

CGM technology has grown rapidly and is more accessible and accurate. The Glucose Management Indicator (GMI) and data on TIR, hypoglycemia, and hyperglycemia are available to providers and patients via standardized reports such as the AGP (Figure 6.1). Visual cues and recommendations are offered to assist in data interpretation and treatment decision-making.

Key points included in standard AGP report. Adapted from Battelino T, Danne T, Bergenstal RM, et al. Diabetes Care 2019;42:1593–1603.

Key points included in standard AGP report. Adapted from Battelino T, Danne T, Bergenstal RM, et al. Diabetes Care 2019;42:1593–1603.

Glycemic Goals

Recommendations

Reassess glycemic targets over time based on patient and disease factors. (See Figure 6.2 and Table 12.1 in the complete 2021 Standards of Care.) Table 6.3 summarizes glycemic recommendations for many nonpregnant adults. For specific guidance, see “6. Glycemic Targets,” “13. Children and Adolescents,” and “14. Management of Diabetes in Pregnancy” in the complete 2021 Standards of Care.

Summary of Glycemic Recommendations for Many Nonpregnant Adults With Diabetes

. .
A1C
Preprandial capillary plasma glucose 80–130 mg/dL* (4.4–7.2 mmol/L)
Peak postprandial capillary plasma glucose†
. .
A1C
Preprandial capillary plasma glucose 80–130 mg/dL* (4.4–7.2 mmol/L)
Peak postprandial capillary plasma glucose†

More or less stringent glycemic goals may be appropriate for individual patients. #CGM may be used to assess glycemic target as noted in Recommendation 6.5b and Figure 6.1. Goals should be individualized based on duration of diabetes, age/life expectancy, comorbid conditions, known CVD or advanced microvascular complications, hypoglycemia unawareness, and individual patient considerations. †Postprandial glucose may be targeted if A1C goals are not met despite reaching preprandial glucose goals. Postprandial glucose measurements should be made 1–2 hours after the beginning of the meal, generally peak levels in patients with diabetes.

CGM may be used to assess glycemic target as noted in Recommendation 6.5b and Figure 6.1. Goals should be individualized based on duration of diabetes, age/life expectancy, comorbid conditions, known CVD or advanced microvascular complications, hypoglycemia unawareness, and individual patient considerations.

Postprandial glucose may be targeted if A1C goals are not met despite reaching preprandial glucose goals. Postprandial glucose measurements should be made 1–2 hours after the beginning of the meal, generally peak levels in patients with diabetes.

Hypoglycemia

The classification of hypoglycemia level is defined in Table 6.4.

Classification of Hypoglycemia

. Glycemic Criteria/Description .
Level 1 Glucose
Level 2 Glucose
Level 3 A severe event characterized by altered mental and/or physical status requiring assistance for treatment of hypoglycemia
. Glycemic Criteria/Description .
Level 1 Glucose
Level 2 Glucose
Level 3 A severe event characterized by altered mental and/or physical status requiring assistance for treatment of hypoglycemia

Reprinted from Agiostratidou G, Anhalt H, Ball D, et al. Diabetes Care 2017;40:1622–1630.

Recommendations

7. Diabetes Technology

Diabetes technology describes the devices, software, and hardware used to manage diabetes. It includes delivery systems such as insulin pumps, pens, and syringes as well as CGM devices and glucose meters. Newer forms of diabetes technology include hybrid devices that both monitor glucose and deliver insulin, sometimes via automated algorithms. Mobile applications and software provide diabetes self-management support. Increased patient interest has increased the use of diabetes technology in the primary care setting.

Recommendation

SMBG

Recommendations

CGM Devices

See Table 7.3 for definitions of types of CGM devices.

Type of CGM . Description .
Real-time CGM CGM systems that measure and display glucose levels continuously
Intermittently scanned CGM CGM systems that measure glucose levels continuously but only display glucose values when swiped by a reader or a smartphone
Professional CGM CGM devices that are placed on the patient in the provider’s office (or with remote instruction) and worn for a discrete period of time (generally 7–14 days). Data may be blinded or visible to the person wearing the device. The data are used to assess glycemic patterns and trends. These devices are not fully owned by the patient—they are a clinic-based device, as opposed to the patient-owned real-time or intermittently scanned CGM devices.
Type of CGM . Description .
Real-time CGM CGM systems that measure and display glucose levels continuously
Intermittently scanned CGM CGM systems that measure glucose levels continuously but only display glucose values when swiped by a reader or a smartphone
Professional CGM CGM devices that are placed on the patient in the provider’s office (or with remote instruction) and worn for a discrete period of time (generally 7–14 days). Data may be blinded or visible to the person wearing the device. The data are used to assess glycemic patterns and trends. These devices are not fully owned by the patient—they are a clinic-based device, as opposed to the patient-owned real-time or intermittently scanned CGM devices.

Recommendations

Data derived by CGM allows providers to analyze patient data using new metrics for glycemic targets. These metrics include average blood glucose, percentage of TIR (70–180 mg/dL), glycemic variability, and percentage of time spent above and below range.

Combined Insulin Pump and Sensor Systems

See “7. Diabetes Technology” in the complete 2021 Standards of Care for more information.

The Future

Diabetes technology must be adapted for the individual needs of the patient. Education is essential to ensure that patients can appropriately engage with their diabetes devices to reap the potential health benefits. Both patients and providers must have realistic expectations and understand the capabilities of these new technologies.

8. Obesity Management for the Treatment of Type 2 Diabetes

Strong evidence exists that treatment of obesity can slow the progression of prediabetes to diabetes and benefit those with type 2 diabetes. Modest and sustained weight loss has been shown to improve glycemic control and reduce the need for glucose-lowering medications.

Assessment

Recommendations

Use BMI to document weight status. Providers should advise patients that higher BMIs increase the risks of diabetes, CVD, all-cause mortality, and adverse quality of life outcomes. Providers should assess patients’ readiness to engage in behavior changes for weight loss. Shared decision-making should be used to determine behavioral and weight-loss goals and patient-appropriate intervention strategies.

Diet, Physical Activity, and Behavioral Therapy

Recommendations

Among patients with both type 2 diabetes and overweight or obesity who have inadequate glycemic, blood pressure, and lipid control and/or other obesity-related medical conditions, modest and sustained weight loss improves glycemic control, blood pressure, and lipids and may reduce the need for medications to control these risk factors.

Pharmacotherapy

Recommendations

Nearly all FDA-approved medications for weight loss have been shown to improve glycemic control in patients with type 2 diabetes and delay progression to diabetes for those at risk. Table 8.2 in the complete 2021 Standards of Care provides information on FDA-approved medications for obesity.

Given the high cost, limited insurance coverage, and paucity of data in people with diabetes, medical devices for weight loss are not considered to be the standard of care for obesity management in people with type 2 diabetes.

Metabolic Surgery

Recommendations

A substantial body of evidence has now been accumulated, including data from numerous randomized controlled (nonblinded) clinical trials, demonstrating that metabolic surgery achieves superior glycemic control and reduction of CV risk factors in patients with type 2 diabetes and obesity compared with various lifestyle/medical interventions.

Longer-term concerns include dumping syndrome (nausea, colic, and diarrhea), vitamin and mineral deficiencies, anemia, osteoporosis, and severe hypoglycemia. Long-term nutritional and micronutrient deficiencies and related complications occur with variable frequency depending on the type of procedure and require lifelong vitamin/nutritional supplementation; thus, long-term lifestyle support and routine monitoring of micronutrient and nutritional status should be provided to patients after surgery.

9. Pharmacologic Approaches to Glycemic Treatment

Pharmacologic Therapy for Type 1 Diabetes

Recommendations

See “9. Pharmacologic Approaches to Glycemic Treatment” in the complete 2021 Standards of Care for more detailed information on pharmacologic approaches to type 1 diabetes management.

Pharmacologic Therapy for Type 2 Diabetes

Figure 9.1, Figure 9.2, and Table 9.1 provide details for informed decision-making on pharmacologic agents for type 2 diabetes.

Glucose-lowering medication in type 2 diabetes: 2021 ADA Professional Practice Committee adaptation of Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41: 2669–2701 and Buse JB, Wexler DJ, Tsapas A, et al. Diabetes Care 2020;43:487–493. For appropriate context, see Figure 4.1. In this version, the “Indicators of high-risk or established ASCVD, CKD, or HF” pathway was adapted based on trial populations studied. DPP-4i, DPP-4 inhibitor; GLP-1 RA, GLP-1 receptor agonist; LVEF, left ventricular ejection fraction; SGLT2i, SGLT2 inhibitor; SU, sulfonylurea; T2D, type 2 diabates; TZD, thiazolidinedione.

Glucose-lowering medication in type 2 diabetes: 2021 ADA Professional Practice Committee adaptation of Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41: 2669–2701 and Buse JB, Wexler DJ, Tsapas A, et al. Diabetes Care 2020;43:487–493. For appropriate context, see Figure 4.1. In this version, the “Indicators of high-risk or established ASCVD, CKD, or HF” pathway was adapted based on trial populations studied. DPP-4i, DPP-4 inhibitor; GLP-1 RA, GLP-1 receptor agonist; LVEF, left ventricular ejection fraction; SGLT2i, SGLT2 inhibitor; SU, sulfonylurea; T2D, type 2 diabates; TZD, thiazolidinedione.

FIGURE 9.2. Intensifying to injectable therapies. FPG, fasting plasma glucose; FRC, fixed-ratio combination; GLP-1 RA, GLP-1 receptor agonist; max, maximum; PPG, postprandial glucose. Adapted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Intensifying to injectable therapies. FPG, fasting plasma glucose; FRC, fixed-ratio combination; GLP-1 RA, GLP-1 receptor agonist; max, maximum; PPG, postprandial glucose. Adapted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

FIGURE 9.2. Intensifying to injectable therapies. FPG, fasting plasma glucose; FRC, fixed-ratio combination; GLP-1 RA, GLP-1 receptor agonist; max, maximum; PPG, postprandial glucose. Adapted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Intensifying to injectable therapies. FPG, fasting plasma glucose; FRC, fixed-ratio combination; GLP-1 RA, GLP-1 receptor agonist; max, maximum; PPG, postprandial glucose. Adapted from Davies MJ, D’Alessio DA, Fradkin J, et al. Diabetes Care 2018;41:2669–2701.

Drug-specific and patient factors to consider when selecting antihyperglycemic treatment in adults with type 2 diabetes

*For agent-specific dosing recommendations, please refer to the manufacturers’ prescribing information. †FDA-approved for CVD benefit. ‡FDA-approved for HF indication. §FDA-approved for CKD indication. GI, gastrointestinal; GLP-1 RA, GLP-1 receptor agonist; NASH, nonalcoholic steatohepatitis; SQ, subcutaneous; T2D, type 2 diabetes.

Recommendations

10. CVD and Risk Management

ASCVD—defined as coronary heart disease (CHD), cerebrovascular disease, or peripheral arterial disease (PAD) presumed to be of atherosclerotic origin—is the leading cause of morbidity and mortality for people with diabetes. HF is another major cause of morbidity and mortality from CVD. For prevention and management of both ASCVD and HF, CV risk factors should be assessed at least annually in all patients with diabetes. These risk factors include obesity/overweight, hypertension, dyslipidemia, smoking, a family history of premature coronary disease, chronic kidney disease (CKD), and the presence of albuminuria.

The Risk Calculator

The American College of Cardiology/American Heart Association ASCVD risk calculator (Risk Estimator Plus) is a useful tool to estimate 10-year ASCVD risk (tools.acc.org/ASCVD-Risk-Estimator-Plus).

Hypertension/Blood Pressure Control

Hypertension, defined as a sustained blood pressure ≥140/90 mmHg, is common among patients with either type 1 or type 2 diabetes.

Recommendations

Screening and Diagnosis
Treatment Goals

Treatment Strategies

Lifestyle Intervention

Recommendation

Pharmacologic Interventions

Recommendations

Multiple-drug therapy is often required to achieve blood pressure targets, particularly in the setting of DKD. Titration of and/or addition of further blood pressure medications should be made in a timely fashion to overcome therapeutic inertia in achieving blood pressure goals. (See Figure 10.1 in the complete 2021 Standards of Care.)

Lipid Management

Lifestyle Intervention

Recommendations

Ongoing Therapy and Monitoring With Lipid Panel

Recommendations

Statin Treatment

Primary Prevention

Recommendations

Secondary Prevention

Recommendations

Patients with type 2 diabetes have an increased prevalence of lipid abnormalities, contributing to their high risk of ASCVD. Multiple clinical trials have demonstrated the beneficial effects of statin therapy on ASCVD outcomes in subjects with and without CHD. Statins are the drugs of choice for LDL cholesterol lowering and cardioprotection. High-intensity statin therapy will achieve a reduction of approximately ≥50% in LDL cholesterol, and moderate-intensity statin regimens achieve 30–49% reductions in LDL cholesterol.

Treatment of Other Lipoprotein Fractions or Targets

Recommendations

Other Combination Therapy

Recommendations

Diabetes Risk With Statin Use

A meta-analysis of 13 randomized statin trials with 91,140 participants showed an odds ratio of 1.09 for a new diagnosis of diabetes, so that (on average) treatment of 255 patients with statins for 4 years resulted in one additional case of diabetes while simultaneously preventing 5.4 vascular events among those 255 patients.

Lipid-Lowering Agents and Cognitive Function

The most recent systematic review of the FDA’s post-marketing surveillance databases, randomized controlled trials, and cohort, case-control, and cross-sectional studies evaluating cognition in patients receiving statins found that published data do not reveal an adverse effect of statins on cognition.

Antiplatelet Agents

Recommendations

Risk Reduction

Aspirin is effective in reducing CV morbidity and mortality in high-risk patients with previous myocardial infarction (MI) or stroke (secondary prevention) and is strongly recommended.

In primary prevention, however, the benefit is more controversial. The use of aspirin needs to be carefully considered in the context of shared decision-making, weighing the CV benefits with the fairly comparable increase in risk of bleeding; generally, it may not be recommended. Aspirin may be considered in the context of high CV risk with low bleeding risk, but generally not in older adults. Aspirin is not recommended for those at low risk of ASCVD (such as men and women aged

CVD

Recommendations

Screening
Treatment

CV outcomes trials (CVOTs) of dipeptidyl peptidase 4 (DPP-4) inhibitors have all, so far, not shown CV benefits relative to placebo. Numerous large randomized controlled trials have reported statistically significant reductions in CV events for three of the FDA-approved SGLT2 inhibitors (empagliflozin, canagliflozin, and dapagliflozin) and four FDA-approved GLP-1 receptor agonists (liraglutide, albiglutide [although that agent was removed from the market for business reasons], semaglutide [lower risk of CV events in a moderate-sized clinical trial but one not powered as a CVOT], and dulaglutide). SGLT2 inhibitors also appear to reduce risk of HF hospitalization and progression of kidney disease in patients with established ASCVD, multiple risk factors for ASCVD, or DKD.

In patients with type 2 diabetes and established ASCVD, multiple ASCVD risk factors, or DKD, an SGLT2 inhibitor with demonstrated CV benefit is recommended to reduce the risk of MACE and/or HF hospitalization. In patients with type 2 diabetes and established ASCVD or multiple risk factors for ASCVD, a GLP-1 receptor agonist with demonstrated CV benefit is recommended to reduce the risk of MACE. For many patients, use of either an SGLT2 inhibitor or a GLP-1 receptor agonist to reduce CV risk is appropriate. It is unknown whether use of both classes of drugs will provide an additive CV outcomes benefit. In patients with type 2 diabetes and established HFrEF, an SGLT2 inhibitor with proven benefit in this patient population is recommended to reduce the risk of worsening HF and CV death.

11. Microvascular Complications and Foot Care

CKD

Recommendations

Screening
Treatment

Epidemiology of Diabetes and CKD

CKD is diagnosed by the persistent presence of elevated urinary albumin excretion (albuminuria), low eGFR, or other manifestations of kidney damage (Figure 11.1). Among people with type 1 or type 2 diabetes, the presence of CKD markedly increases CV risk and health care costs.

FIGURE 11.1

FIGURE 11.1. Risk of CKD progression, frequency of visits, and referral to nephrology according to glomerular filtration rate (GFR) and albuminuria. The GFR and albuminuria grid depicts the risk of progression, morbidity, and mortality by color, from best to worst (green, yellow, orange, red, dark red). The numbers in the boxes are a guide to the frequency of visits (number of times per year). Green can reflect CKD with normal eGFR and albumin-to-creatinine ratio only in the presence of other markers of kidney damage, such as imaging showing polycystic kidney disease or kidney biopsy abnormalities, with follow-up measurements annually; yellow requires caution and measurements at least once per year; orange requires measurements twice per year; red requires measurements three times per year; and dark red requires measurements four times per year. These are general parameters only, based on expert opinion, and underlying comorbid conditions and disease state as well as the likelihood of impacting a change in management for any individual patient must be taken into account. “Refer” indicates that nephrology services are recommended. *Referring clinicians may wish to discuss with their nephrology service, depending on local arrangements regarding treating or referring. <a href=Reprinted with permission from Vassalotti JA, Centor R, Turner BJ, Greer RC, Choi M, Sequist TD; National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Am J Med 2016;129:153–162.e7." />

Risk of CKD progression, frequency of visits, and referral to nephrology according to glomerular filtration rate (GFR) and albuminuria. The GFR and albuminuria grid depicts the risk of progression, morbidity, and mortality by color, from best to worst (green, yellow, orange, red, dark red). The numbers in the boxes are a guide to the frequency of visits (number of times per year). Green can reflect CKD with normal eGFR and albumin-to-creatinine ratio only in the presence of other markers of kidney damage, such as imaging showing polycystic kidney disease or kidney biopsy abnormalities, with follow-up measurements annually; yellow requires caution and measurements at least once per year; orange requires measurements twice per year; red requires measurements three times per year; and dark red requires measurements four times per year. These are general parameters only, based on expert opinion, and underlying comorbid conditions and disease state as well as the likelihood of impacting a change in management for any individual patient must be taken into account. “Refer” indicates that nephrology services are recommended. *Referring clinicians may wish to discuss with their nephrology service, depending on local arrangements regarding treating or referring. Reprinted with permission from Vassalotti JA, Centor R, Turner BJ, Greer RC, Choi M, Sequist TD; National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Am J Med 2016;129:153–162.e7.

FIGURE 11.1

FIGURE 11.1. Risk of CKD progression, frequency of visits, and referral to nephrology according to glomerular filtration rate (GFR) and albuminuria. The GFR and albuminuria grid depicts the risk of progression, morbidity, and mortality by color, from best to worst (green, yellow, orange, red, dark red). The numbers in the boxes are a guide to the frequency of visits (number of times per year). Green can reflect CKD with normal eGFR and albumin-to-creatinine ratio only in the presence of other markers of kidney damage, such as imaging showing polycystic kidney disease or kidney biopsy abnormalities, with follow-up measurements annually; yellow requires caution and measurements at least once per year; orange requires measurements twice per year; red requires measurements three times per year; and dark red requires measurements four times per year. These are general parameters only, based on expert opinion, and underlying comorbid conditions and disease state as well as the likelihood of impacting a change in management for any individual patient must be taken into account. “Refer” indicates that nephrology services are recommended. *Referring clinicians may wish to discuss with their nephrology service, depending on local arrangements regarding treating or referring. <a href=Reprinted with permission from Vassalotti JA, Centor R, Turner BJ, Greer RC, Choi M, Sequist TD; National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Am J Med 2016;129:153–162.e7." />

Risk of CKD progression, frequency of visits, and referral to nephrology according to glomerular filtration rate (GFR) and albuminuria. The GFR and albuminuria grid depicts the risk of progression, morbidity, and mortality by color, from best to worst (green, yellow, orange, red, dark red). The numbers in the boxes are a guide to the frequency of visits (number of times per year). Green can reflect CKD with normal eGFR and albumin-to-creatinine ratio only in the presence of other markers of kidney damage, such as imaging showing polycystic kidney disease or kidney biopsy abnormalities, with follow-up measurements annually; yellow requires caution and measurements at least once per year; orange requires measurements twice per year; red requires measurements three times per year; and dark red requires measurements four times per year. These are general parameters only, based on expert opinion, and underlying comorbid conditions and disease state as well as the likelihood of impacting a change in management for any individual patient must be taken into account. “Refer” indicates that nephrology services are recommended. *Referring clinicians may wish to discuss with their nephrology service, depending on local arrangements regarding treating or referring. Reprinted with permission from Vassalotti JA, Centor R, Turner BJ, Greer RC, Choi M, Sequist TD; National Kidney Foundation Kidney Disease Outcomes Quality Initiative. Am J Med 2016;129:153–162.e7.

Selection of Glucose-Lowering Medications for Patients With CKD

For patients with type 2 diabetes and established CKD, special considerations for the selection of glucose-lowering medications include limitations to available medications when eGFR is diminished and a desire to mitigate high risks of CKD progression, CVD, and hypoglycemia. Drug dosing may require modification with eGFR

SGLT2 inhibitors and GLP-1 receptor agonists should be considered for patients with type 2 diabetes and CKD who require another drug added to metformin to attain target A1C or cannot use or tolerate metformin. SGLT2 inhibitors reduce risks of CKD progression, CVD events, and hypoglycemia. GLP-1 receptor agonists are suggested because they reduce risks of CVD events and hypoglycemia and appear to possibly slow CKD progression.

For patients with type 2 diabetes and CKD, the selection of specific agents may depend on comorbidity and CKD stage. SGLT2 inhibitors may be more useful for patients at high risk of CKD progression (i.e., with albuminuria or a history of documented eGFR loss) (Figure 9.1) because they appear to have large beneficial effects on CKD incidence. The SGLT2 inhibitors empagliflozin and dapagliflozin are approved by the FDA for use with eGFR ≥45 mL/min/1.73 m 2 .

CVD and Blood Pressure

Hypertension is a strong risk factor for the development and progression of CKD. Two clinical trials studied the combinations of ACE inhibitors and ARBs and found no benefits on CVD or CKD, and the drug combination had higher adverse event rates (hyperkalemia and/or acute kidney injury). Therefore, the combined use of ACE inhibitors and ARBs should be avoided.

Diabetic Retinopathy

Recommendations

Screening
Treatment

Neuropathy

Recommendations

Screening
Treatment

Foot Care

Recommendations

Foot ulcers and amputation are consequences of diabetic neuropathy and PAD. Early recognition and treatment of patients at risk can delay or prevent adverse outcomes. See “11. Microvascular Complications and Foot Care” in the complete 2021 Standards of Care for specifics regarding comprehensive foot exams.

12. Older Adults

Recommendations

More than one-fourth of people over the age of 65 years have diabetes and one-half of older adults have prediabetes. Diabetes management in older adults requires regular assessment of medical, psychological, functional, and social domains. Older adults with diabetes have higher rates of premature death, functional disability, accelerated muscle loss, and coexisting illnesses, such as hypertension, CHD, and stroke, than older adults without diabetes. Screening for diabetes complications in older adults should be individualized and periodically revisited, as the results of screening tests may impact targets and therapeutic approaches.

Neurocognitive Function

Recommendation

Older adults with diabetes are at higher risk of institutionalization and cognitive impairment, which can make it challenging for clinicians to help their patients reach individualized glycemic, blood pressure, and lipid targets. People with diabetes have higher incidences of all-cause dementia, Alzheimer disease, and vascular dementia than people with normal glucose tolerance.

Hypoglycemia

Recommendations

Older adults are at higher risk of hypoglycemia for many reasons, including insulin deficiency necessitating insulin therapy and progressive renal insufficiency. Glycemic targets and pharmacologic regimens may need to be adjusted to minimize the occurrence of hypoglycemic events. Patients and their caregivers should be routinely queried about hypoglycemia and hypoglycemia unawareness.

Treatment Goals

Recommendations

Providers caring for older adults with diabetes must take clinical, cognitive, and functional heterogeneity into consideration when setting and prioritizing treatment goals. (See Table 12.1 in the complete 2021 Standards of Care.) Patients who can be expected to live long enough to reap the benefits of long-term intensive diabetes management, who have good cognitive and physical function, and who choose to do so via shared decision-making may be treated using therapeutic interventions and goals similar to those for younger adults with diabetes.

Lifestyle Management

Recommendations

Pharmacologic Therapy

Recommendations

Special care is required in prescribing and monitoring pharmacologic therapies in older adults. Metformin is the first-line agent for older adults with type 2 diabetes. See Figure 9.1 for general recommendations regarding glucose-lowering treatment for adults with type 2 diabetes and Table 9.1 for patient- and drug-specific factors to consider when selecting glucose-lowering agents.

The needs of older adults with diabetes and their caregivers should be evaluated to construct a tailored care plan.

Due in part to the success of modern diabetes management, patients with type 1 diabetes are living longer, and the population of these patients >65 years of age is growing. Some of these patients may be using insulin pumps and/or CGM systems. To avoid DKA, older adults with type 1 diabetes need some form of basal insulin even when they are unable to ingest meals.

Treatment in Skilled Nursing Facilities and Nursing Homes

Recommendations

Management of diabetes is unique in the LTC setting. Special management considerations include the need to avoid both hypoglycemia and the complications of hyperglycemia. Older adults with diabetes in LTC are especially vulnerable to hypoglycemia.

An older adult residing in an LTC facility may have irregular and unpredictable meal consumption, undernutrition, anorexia, and impaired swallowing. Diets tailored to patients’ culture, preferences, and personal goals may increase quality of life, satisfaction with meals, and nutrition status.

End-of-Life Care

Recommendations

Overall, palliative medicine promotes comfort, symptom control and prevention (pain, hypoglycemia, hyperglycemia, and dehydration), and preservation of dignity and quality of life in patients with limited life expectancy. Strict glucose and blood pressure control may not be consistent with achieving comfort and quality of life. Glucose targets should aim to prevent hypoglycemia and hyperglycemia. Different patient categories, including stable patients, patients with organ failure, and dying patients, have been proposed for diabetes management in those with advanced disease.

13. Children and Adolescents

The management of diabetes in children and adolescents cannot simply be derived from care routinely provided to adults with diabetes. The epidemiology, pathophysiology, developmental considerations, and response to therapy in pediatric-onset diabetes are different from adult diabetes.

See “13. Children and Adolescents” in the complete 2021 Standards of Care for specific recommendations regarding the treatment of type 1 diabetes in this group, as well as the comprehensive treatment of children with type 2 diabetes, including screening, prevention and management of CV risk factors, microvascular complications, and other associated conditions. See “7. Diabetes Technology” in the complete 2021 Standards of Care for more information on the use of blood glucose meters, CGM, and insulin pumps. The ADA position statements “Type 1 Diabetes in Children and Adolescents” and “Evaluation and Management of Youth-Onset Type 2 Diabetes” offer additional information.

Type 1 Diabetes

Type 1 diabetes is the most common form of diabetes in youth. The provider must consider the unique aspects of care and management of children and adolescents with type 1 diabetes. A multidisciplinary team of specialists trained in pediatric diabetes management and sensitive to the challenges of children and adolescents with type 1 diabetes and their families should provide care for this population.

Type 2 Diabetes

Type 2 diabetes in youth has increased over the past 20 years, and recent estimates suggest an incidence of ∼5,000 new cases per year in the U.S. Evidence suggests that type 2 diabetes in youth is different not only from type 1 diabetes, but also from type 2 diabetes in adults.

Management

Treatment of youth-onset type 2 diabetes by a multidisciplinary team should include lifestyle management, diabetes self-management education, and pharmacologic treatment. Current pharmacologic treatment options for youth-onset type 2 diabetes are limited to three approved drugs: insulin, metformin, and liraglutide.

Most youth with type 2 diabetes come from racial/ethnic minority groups, have low socioeconomic status, and often experience multiple psychosocial stressors. Consideration of the sociocultural context and efforts to personalize diabetes management are of critical importance to minimize barriers to care, enhance adherence, and maximize response to treatment.