What is the HbA1c (hemoglobin A1c) target in patients with type 2 diabetes mellitus and multiple comorbid medical conditions?

From the Guidelines

The HbA1c target for patients with type 2 diabetes and multiple medical conditions should be individualized, with a general target of 7% to 8% for most adults, as recommended by the American College of Physicians 1. This target range is based on the balance of benefits and harms of glycemic control, considering factors such as risk of hypoglycemia, life expectancy, diabetes duration, established vascular complications, major comorbidities, patient preferences, and access to resources. The American College of Physicians guidance statement 1 also emphasizes the importance of personalizing goals for glycemic control, taking into account the patient's general health, life expectancy, treatment burden, and costs of care. For patients with limited life expectancy, frailty, cognitive impairment, or extensive comorbidities, a less stringent target may be appropriate, while younger patients with recent-onset diabetes and no significant comorbidities may aim for stricter targets if achievable without significant hypoglycemia. Regular monitoring every 3-6 months is essential to assess whether targets are being met and to adjust therapy accordingly. The 2020 update to the management of hyperglycemia in type 2 diabetes by the American Diabetes Association and the European Association for the Study of Diabetes 1 also supports individualized HbA1c targets, considering the patient's risk factors, comorbidities, and personal preferences. Additionally, the KDOQI clinical practice guideline for diabetes and CKD: 2012 update 1 suggests that target HbA1c be extended above 7.0% in individuals with comorbidities or limited life expectancy and risk of hypoglycemia. However, the most recent and highest-quality study 1 provides the strongest evidence for the recommended target range of 7% to 8% for most adults with type 2 diabetes. Key factors to consider when individualizing HbA1c targets include:

• Risk of hypoglycemia
• Life expectancy
• Diabetes duration
• Established vascular complications
• Major comorbidities
• Patient preferences and access to resources
• Capacity for adequate monitoring of hypoglycemia
• Other harms. By considering these factors and aiming for a target range of 7% to 8%, clinicians can provide personalized care for patients with type 2 diabetes and multiple medical conditions, balancing the benefits of glycemic control with the risks of hypoglycemia and treatment burden.

From the Research

HbA1c Target in Type 2 Diabetes with Multiple Medical Conditions

• The optimal HbA1c target level for patients with type 2 diabetes is a subject of controversy, with guidelines yielding differing recommendations 2.
• The American College of Physicians (ACP) recommends an HbA1c target level between 7% and 8% for most patients, while the American Diabetes Association suggests aiming for HbA1c levels less than 7% for many nonpregnant adults 2.
• A study found that an HbA1c goal of 7% produced higher quality-adjusted life-years (QALYs) compared with a goal of 8% for all regimens 3.
• Another study suggested that the proportion of patients who achieved the HbA1c goal ranged from 25.9% with α-glucosidase inhibitors to 63.2% with the long-acting glucagon-like peptide-1 analogue 4.
• The choice of second-line therapy after metformin is less well defined, but sulfonylureas may be considered as a clinically stable choice for second-line therapy after completing maximally tolerated doses of metformin 5.
• However, sulfonylureas as add-on therapy to metformin are associated with increased risk of all-cause mortality and major hypoglycemic episodes compared with other oral hypoglycemic agents (OHAs) 6.

Factors Influencing HbA1c Target

• Baseline HbA1c is an important determinant of observed efficacy, with a progressive decrease in the proportion of patients at target for each 0.5% increase in baseline HbA1c 4.
• Cardiovascular risks, risk of hypoglycemia, metabolic changes, and cost are also important factors to consider when selecting a second-line therapy 5.
• The use of sulfonylureas as second-line therapy for type 2 diabetes generated glycemic control and QALYs comparable with those associated with other agents but at lower cost 3.

Clinical Implications

• Clinicians should individualize HbA1c target levels for patients with type 2 diabetes, taking into account factors such as cardiovascular risks, risk of hypoglycemia, and metabolic changes 2.
• The choice of second-line therapy after metformin should be based on a careful consideration of the patient's individual characteristics and medical history 5, 6.