Prolongation of Near-Normoglycemic Remission in Black NIDDM Subjects With Chronic Low-Dose Sulfonylurea Treatment

Microvascular and neuropathic complications of diabetes mellitus can be significantly decreased by long-term, near-normoglycemic regulation in patients with insulin-dependent diabetes mellitus. Prevention or delay of onset of hyperglycemia in non-insulin-dependent diabetes mellitus (NIDDM) patients should reduce morbidity and mortality from these complications. NIDDM can be nearly normoglycemic when diagnosed by screening before its symptomatic stage or when clinically hyperglycemic NIDDM goes into remission. One potential strategy to delay the onset of hyperglycemia in individuals at high risk is chronic low-dose sulfonylurea therapy. Thirty black NIDDM subjects who recently had developed near-normoglycemia were followed with no treatment or were randomly assigned to a 3-year, double-blind glipizide or placebo treatment. Baseline and follow-up parameters included fasting plasma glucose (FPG), HbA_1c, plasma insulin, and glucose responses to an oral glucose tolerance test and insulin action, as determined by the euglycemic insulin clamp. Baseline FPG and HbA_1c for all three groups were 107 mg/dl and 4.7%, respectively. Relapse to hyperglycemia was defined as an FPG level ≥ 140 mg/dl on several consecutive visits or an FPG level ≥ 140 mg/dl and symptoms of hyperglycemia. During the course of the treatment and follow-up, hyperglycemia occurred in 6 of 10 subjects in the no treatment group, 6 of 10 in the placebo group, and 2 of 10 in the glipizide treatment group. Prolongation of near-normoglycemia was significantly (P < 0.05) increased by low-dose (2.5 mg/day) glipizide compared with placebo treatment. Low-dose sulfonylurea therapy delays the onset of hyperglycemia in NIDDM subjects in remission and may be a useful method to delay the onset of NIDDM in high-risk individuals.