To compare the effect of morning and bedtime NPH insulin combined with daytime sulfonylurea on glycemic control in non-insulin-dependent diabetes mellitus (NIDDM) patients no longer responding to treatment with sulfonylureas alone.
Twenty-four NIDDM patients who fulfilled these criteria were randomized to treatment with Protaphan human insulin in the morning or at bedtime (22 ± 1 IU) plus 3.5 mg glibenclamide twice a day.
Morning and bedtime NPH insulin resulted in equal reduction of HbA1 (from 13.5 ± 0.3 to 9.4 ± 0.1 and 9.6 ± 0.2%, respectively) and mean self-monitored blood glucose (9.2 ± 0.5 vs. 10.1 ± 0.4 mM). Bedtime insulin resulted in lower morning blood glucose (7.8 ± 0.5 vs. 9.1 ± 0.4 mM; P < 0.01), whereas morning insulin resulted in lower evening blood glucose (10.1 ± 0.6 vs 12.1 ± 0.6 mM, P < 0.01).
Morning and bedtime NPH insulin combined with glibenclamide are equipotent in the treatment of NIDDM patients with secondary failure to sulfonylurea. However, this treatment regimen normalizes blood glucose only in a small group of patients. Therefore, more intensified insulin therapy seems to be required to achieve this goal.
