Insulin treatment for type 2 diabetes: When to start, which to use
ABSTRACTIn type 2 diabetes mellitus, oral hypoglycemic agents and analogues of glucagon-like peptide-1 provide adequate glycemic control early in the disease. Insulin therapy becomes necessary for those with advanced disease. Further, some experts recommend electively starting insulin therapy in early diabetes. This review addresses practical approaches to insulin therapy, particularly when it is indicated and which regimen to use.
KEY POINTS
- Whether to start insulin therapy and which regimen to use depend on a number of factors, including the patient’s acceptance and willingness to adhere to the therapy.
- A common way to start is to add a once-daily dose of a long-acting insulin at bedtime (basal insulin) to the patient’s antidiabetic regimen.
- Basal regimens do not control postprandial hyperglycemia very well. Another option is to take a long-acting (basal) insulin along with a rapid-acting (prandial or bolus) insulin before meals. Multiple formulations of premixed insulins are available and are convenient to use among new users.
- Basal-bolus regimens, which involve injections of rapid-acting insulin before meals and long-acting insulin at bedtime, are gaining popularity. Their cost and the number of injections may affect patient acceptance of this treatment.
COST VS CONTROL
Newer insulin analogues make insulin treatment safer and more accepted by patients. The availability of several options for insulin regimens allows individualization of the treatment according to the patient’s acceptance, the safety profile, and the cost.
Patient selection and insulin titration are key issues in ensuring the achievement of adequate control with the fewest side effects. Lifestyle management (diet and physical activity) enhances the efficacy of insulin therapy and reduces the chances of side effects, namely fluctuation of glucose levels, hypoglycemic episodes, and weight gain.
Human insulins (NPH and regular) remain the least expensive, especially when using premixed NPH-regular insulin 70/30. Their use should be considered when the cost of medication is a major concern for the patient. A more relaxed goal of glycemic control may be considered in order to avoid hypoglycemia when using those insulin preparations, such as a hemoglobin A1c level less than 7.5% or even in the range of 7.5% to 8.5%, depending on the expected seasonal variation of hemoglobin A1c (which is higher in winter43), individual factors, and whether the premixed insulin is used twice or three times daily.
RE-EVALUATE THE REGIMEN ROUTINELY
The insulin regimen should be re-evaluated routinely. It might need to be changed in response to the dynamic multifactorial process of progression of diabetes, change in stress level, presence or resolution of intercurrent illnesses, risk of hypoglycemia, concerns about weight gain, and cost.
Finally, adjustment of the regimen should be considered in response to improvement of glycemic control related to improvement of dietary management, exercising, weight loss, and medical therapies.
