The American Diabetes Association (ADA) 2021 Standards of Medical Care in Diabetes includes new and updated recommendations based on the latest scientific diabetes research and clinical trials. The key updates cover diabetes treatment in people with chronic kidney disease and heart failure, the use of technology for diabetes management and recommendations for continuous glucose monitoring (CGM). The update also includes vaccine-specific updates, including those related to COVID-19.

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Here are the key points covered in the update:

• Classification and diagnosis
• Prevention of delay of type 2 diabetes
• Assessment of comorbidities
• Evaluation of DSMES
• Glycaemic targets & pharmacologic approaches to treatment
• Professional CGM
• CV risk management

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Classification and diagnosis

Use of the term LADA

There is a debate as to whether slowly progressive autoimmune diabetes with an adult onset should be termed latent autoimmune diabetes in adults (LADA) or type 1 diabetes. As per the panel, use of the term LADA is common and acceptable in clinical practice and has the practical impact of heightening awareness of a population of adults likely to develop overt autoimmune β-cell destruction, thus accelerating insulin initiation prior to deterioration of glucose control or development of diabetic ketoacidosis (DKA).

Point-of-care A1C assays

The updates also includes guidance on use of point-of-care A1C assays for the diagnosis of diabetes. Point-of-care A1C assays cleared by the FDA for use in the diagnosis of diabetes should only be used. The assays should be used only in the clinical settings for which they are cleared.

Cystic fibrosis–related diabetes

Early diagnosis and treatment of cystic fibrosis–related diabetes (CFRD) is associated with preservation of lung function. Annual screening for CFRD with an oral glucose tolerance test should begin by age 10 years in all patients with cystic fibrosis not previously diagnosed with CFRD.

1. A1C is not recommended as a screening test for cystic fibrosis–related diabetes. Oral glucose tolerance test is the recommended screening test.
2. Patients with cystic fibrosis–related diabetes should be treated with insulin to attain individualised glycaemic goals. The use of insulin is recommended as it induces an anabolic state while promoting macronutrient retention and weight gain.
3. Five years after the diagnosis of cystic fibrosis–related diabetes, annual monitoring for complications of diabetes is recommended.

Post-transplantation diabetes mellitus

Post-transplantation diabetes mellitus (PTDM) refers to the presence of diabetes in the post-transplant setting irrespective of the timing of diabetes onset. Patients should be screened after organ transplantation for hyperglycaemia, with a formal diagnosis of post-transplantation diabetes mellitus being best made once a patient is stable on an immunosuppressive regimen and in the absence of an acute infection. The oral glucose tolerance test is the preferred test to make a diagnosis of post-transplantation diabetes mellitus. For treatment, immunosuppressive regimens shown to provide the best outcomes for patient and graft survival should be used, irrespective of post-transplantation diabetes mellitus risk.

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Prevention or delay of type 2 diabetes

ADA 2021 has included a new subsection, “Delivery and Dissemination of Lifestyle Behavior Change for Diabetes Prevention,” to describe lifestyle behavior change programs to prevent diabetes. As prediabetes is associated with heightened cardiovascular risk; the guideline suggests screening for and treatment of modifiable risk factors for cardiovascular disease.

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Comprehensive medical evaluation and assessment of comorbidities

Ongoing management should be guided by the assessment of overall health status, diabetes complications, and cardiovascular risk using the risk calculator.

The guideline now includes Centers for Disease Control and Prevention–recommended vaccinations for people with diabetes. Important considerations related to coronavirus disease 2019 (COVID-19) has also been added.

Comprehensive diabetes medical evaluation (at initial, follow-up, and annual visits) now also includes factors, such as social determinants of health and identification of surrogate decision maker and advanced care plan.

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Facilitating behavior change and well-being to improve health outcomes

Recommendations regarding barriers to diabetes self-management education and support (DSMES) have been added. Barriers to diabetes self-management education and support exist at the health system, payor, provider, and patient levels. As per the updates, some barriers to diabetes self-management education and support access may be mitigated through telemedicine approaches.

As per the new updates, DSMES needs should be evaluated at:

• Diagnosis
• Annually and/or when not meeting treatment targets
• When complicating factors (health conditions, physical limitations, emotional factors, or basic living needs) develop that influence self-management
• When transitions in life and care occur

Recommendation regarding physical activity has been added. All adults, and particularly those with type 2 diabetes, should decrease the amount of time spent in daily sedentary behavior. Prolonged sitting should be interrupted every 30 minute for blood glucose benefits.

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Glycaemic targets

Assessment of glycaemic status (A1C or other glycaemic measurement) is recommended at least two times a year in patients who are meeting treatment goals (and who have stable glycaemic control). Glycaemic status should be assessed at least quarterly, and as needed, in patients whose therapy has recently changed and/or who are not meeting glycaemic goals.

To include time-in-range goals, the recommendation for glycaemic goals for many non-pregnant adults has been updated. An A1C goal for many non-pregnant adults of <7% (53 mmol/mol) without significant hypoglycaemia is appropriate. If using ambulatory glucose profile/glucose management indicator to assess glycaemia, a parallel goal is a time in range of >70% with time below range <4%.

The panel recommends that occurrence of and risk for hypoglycaemia should be reviewed at every encounter and investigated as indicated.

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Professional CGM

“Blinded” continuous glucose monitoring (CGM) is now termed to as “professional CGM,” which is clinic-based and can include blinded and real-time devices. The ADA now recommends CGM as a useful tool for people with diabetes on multiple daily injections and continuous subcutaneous insulin infusions and other forms of insulin therapy not defined by type of diabetes or age.

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Pharmacologic approaches to glycaemic treatment

Additional evidence has been added for the discussion of use of sensor-augmented insulin pumps.

Recommendation alerting providers of the potential for overbasalisation with insulin therapy have been added. As per the update, clinical signals that may prompt evaluation of overbasalisation include basal dose more than ∼0.5 IU/kg, high bedtime-morning or post-preprandial glucose differential, hypoglycaemia (aware or unaware), and high variability. Indication of overbasalisation should prompt reevaluation to further individualise therapy.

A dedicated decision pathway for chronic kidney disease and a dedicated decision pathway for heart failure have been added. This includes with updates to reflect consensus interpretation of clinical trial data.

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Cardiovascular disease and risk management

The guideline includes updates based on evidence from trials that were specifically designed to assess the impact of cardiovascular risk reduction strategies in patients with type 1 diabetes.

1. ACE inhibitors or angiotensin receptor blockers have been added as first-line therapy for hypertension in people with diabetes and coronary artery disease.
2. New recommendations related to “antiplatelet agents” have been added. As per the panel, long-term treatment with dual antiplatelet therapy should be considered for patients with prior coronary intervention, high ischaemic risk, and low bleeding risk to prevent major adverse cardiovascular events.
3. Combination therapy with aspirin plus low-dose rivaroxaban should be considered for patients with stable coronary and/or peripheral artery disease and low bleeding risk to prevent major adverse limb and cardiovascular events.

With the evolving evidence from cardiovascular outcomes trials, the following new recommendations have been updated:

• In patients with type 2 diabetes and established heart failure with reduced ejection fraction, a sodium–glucose cotransporter 2 inhibitor with proven benefit in this patient population is recommended to reduce risk of worsening heart failure and cardiovascular death
• In patients with known atherosclerotic cardiovascular disease, particularly coronary artery disease, ACE inhibitor or angiotensin receptor blocker therapy is recommended to reduce the risk of cardiovascular events
• In patients with prior myocardial infarction, β-blockers should be continued for 3 years after the event
• Treatment of patients with heart failure with reduced ejection fraction should include a β-blocker with proven cardiovascular outcomes benefit, unless otherwise contraindicated
• In patients with type 2 diabetes with stable heart failure, metformin may be continued for glucose lowering if estimated glomerular filtration rate remains >30 mL/min/1.73 m² but should be avoided in unstable or hospitalized patients with heart failure
• For pregnant patients with diabetes and preexisting hypertension, a blood pressure target of 110–135/85 mmHg is suggested to reduce the risk for accelerated maternal hypertension and minimizing impaired foetal growth