Both glucose monitoring and HbA1c have a role in assessment. The ADA guidelines recommend self-monitoring of blood glucose (SMBG) three times daily for patients using multiple insulin injections or insulin-pump therapy. For others, “SMBG may be useful as a guide to the success of therapy,” the authors write.
HbA1c testing, the primary index of glycemic control, should be performed at least twice a year for those meeting treatment goals and in stable glycemic control and quarterly when treatment has changed or goals have not been met. The target value may vary, depending on such factors as age and hypoglycemia risk. Generally, values below 7% have been shown to reduce microvascular and neuropathic complications of diabetes as well as macrovascular disease, and the ADA guidelines recommend this as a goal for most adult patients.
HbA1c closer to normal (intensive glycemic control) appears to carry greater microvascular benefit but increases the risk of hypoglycemia. The ADA guidelines call intensive glycemic control a reasonable goal for selected patients (e.g., those with diabetes of short duration, a long life expectancy, and no significant CVD).
Conversely, the HbA1c target of <7% may be loosened for patients at significant risk of severe hypoglycemia with limited life expectancy, advanced complications, or extensive comorbidity. “If multiple agents are needed to reach the target, they may bring more harm than benefit,” says Dr. Inzucchi. “New evidence suggests it may be better to back off.”
Drug and nondrug treatment
The ADA guidelines do not provide a detailed algorithm for drug treatment but offer broad recommendations:
For type 1 diabetes, multiple insulin injections with insulin analogues for some patients (e.g., when hypoglycemia is a problem)
For type 2 diabetes, metformin at the time of diagnosis, along with lifestyle changes, with additional agents (including insulin fairly early on) as needed for glycemic control
Medical nutrition therapy should be individualized, but the ADA guidelines generally stress weight loss for overweight or obese individuals, limitations on saturated fat (<7% of total calories) and minimal consumption of trans fats, carbohydrate-intake monitoring, and meal planning to meet the recommended dietary allowances of micronutrients.
Persons with prediabetes should also aim to consume at least 14 g of fiber daily.
The ADA guidelines recommend physical activity for those with or at increased risk of diabetes: at least 150 minutes/week of moderate aerobic exercise (50%-70% maximum heart rate) and (except when contraindicated) three sessions weekly of resistance exercise. Activity may need to be modified in the context of such complications as retinopathy or peripheral neuropathy.