From the Guidelines
Severely elevated Hemoglobin A1c (HbA1c) levels indicate poorly controlled diabetes, requiring immediate intensification of therapy to reduce the risk of microvascular complications such as retinopathy, neuropathy, and diabetic kidney disease 1.
Implications of Severely Elevated HbA1c
- Microvascular disease: lowering A1c to below or approximately 7% has been shown to reduce microvascular and neuropathic complications of type 1 and type 2 diabetes 1.
- Macrovascular disease: in type 1 and type 2 diabetes, randomized controlled trials of intensive versus standard glycemic control have not shown a significant reduction in CVD outcomes during the randomized portion of the trials, however long-term follow-up suggests that treatment to A1c targets below or near 7% in the years soon after the diagnosis of diabetes is associated with long-term reduction in risk of macrovascular disease 1. The general goal of A1c target is below 7%, and initiation or intensification of insulin therapy, such as basal insulin glargine (Lantus) 10-20 units at bedtime or premixed insulin aspart (NovoLog Mix 70/30) 10-20 units with breakfast and dinner, is recommended 1.
Treatment Approach
Additionally, oral hypoglycemic agents, including metformin 1000mg twice daily and/or sitagliptin (Januvia) 100mg daily, may be adjusted or added to the treatment regimen, with close monitoring of blood glucose levels and adjustment of medications as needed to achieve a target A1c level below 7% 1. It is essential to consider the risks and benefits of intensive glycemic control, particularly in patients with a very long duration of diabetes, known history of severe hypoglycemia, advanced atherosclerosis, and advanced age/frailty, and to individualize treatment targets accordingly 1.
From the Research
Implications of Severely Elevated Hemoglobin A1c (HbA1c)
- Severely elevated HbA1c levels are associated with an increased risk of complications in patients with type 2 diabetes, including microvascular and macrovascular events, severe hypoglycemia, and mortality 2.
- A study found that patients with HbA1c levels above 9% had a higher risk of severe hypoglycemia compared to those with HbA1c levels between 7-7.9% 3.
- Another study found that older adults with type 2 diabetes in good health who had HbA1c levels above the recommended range had a significantly elevated complication risk, while those in poor health did not have a significant difference in complication risk regardless of their HbA1c level 2.
- Elevated HbA1c levels are also associated with an increased risk of macrovascular complications, such as cardiovascular disease, and microvascular complications, such as nephropathy, retinopathy, and neuropathy 4.
Risk Factors for Complications
- Diabetes duration and time in range (TIR) are independent risk factors for composite microvascular complications 4.
- Age and HbA1c level are risk factors for macrovascular complications 4.
- TIR is the only independent risk factor for hospitalizations for hypoglycemia or ketoacidosis 4.
Glycemic Control and Complications
- Achieving specific HbA1c levels may not be helpful in reducing the risk of complications in older adults with type 2 diabetes in poor health 2.
- Glycemic control, as measured by HbA1c, is important for preventing complications in patients with type 2 diabetes, but the optimal HbA1c target may vary depending on individual patient characteristics and health status 5, 3, 2.