Addition of sulfonylurea to insulin treatment in poorly controlled type II diabetes. A double-blind, randomized clinical trial
D. S. Schade, W. J. Mitchell and G. Griego
This study examined the potential beneficial effects of the addition of a
second-generation sulfonylurea to insulin therapy for poorly controlled
type II diabetes. A randomized, double-blind, crossover experimental design
was utilized in 16 type II diabetic patients for a period of eight months.
Treatment with glyburide, 20 mg/d (plus insulin), compared with placebo
(plus insulin) resulted in a significant reduction in mean basal glucose
(232 +/- 12 vs 262 +/- 11 mg/dL [12.8 vs 14.4 mmol/L]) and hemoglobin A1C
(10.2% +/- 0.5% vs 10.9% +/- 03%) concentrations. Concomitant with this
change, basal C-peptide and free insulin values increased with glyburide
therapy, but this pharmacological agent did not alter the ability of the
patient's erythrocytes to bind insulin. We conclude that in type II
diabetic subjects receiving more than 28 units of insulin per day, the
addition of glyburide results in a marginal, but statistically significant
improvement in basal glucose concentration, but not in glucose tolerance as
assessed by integrated glucose concentration. Whether this small
improvement in glycemia is worth the additional cost of sulfonylureas or
the risk of drug side effects is not known.
