Comparison of metformin versus sulphonylurea in combination with daily NPH insulin in patients with type 2 diabetes inadequately controlled on hypoglycaemic agents; median follow‐up“29 months

Abstract

AbstractObjectiveTo compare the long‐term effect on glycaemic control and weight gain of metformin versus sulphonylurea combined with daily NPH insulin in patients with type 2 diabetes in routine clinical practice.Research design and methodsA single centre retrospective study of routine clinical care in a busy district general hospital. 208 patients with type 2 diabetes were initiated on combination therapy (bedtime NPH insulin plus an oral hypoglycaemic agent) following inadequate glycaemic control with oral agents alone. 137 were treated with insulin/sulphonylurea (gliclazide 160 mg b.i.d. (n = 135), glipizide 10 mg b.i.d. (n = 2)) and 71 with metformin 850–1000 mg t.i.d. (maximum tolerated dose). Patients were followed up after median (range) 29 (11–58) months therapy. We compared changes in HbA1c and weight, frequency of severe hypoglycaemia, ‘well‐being’ and ‘diabetes treatment satisfaction’ (using validated questionnaires).ResultsAt baseline the groups were matched for glycaemic control, BMI and diabetes duration. The metformin group were heavier (median (range) weight 85 (62–162) versus 80 (43–144) (p = 0.01)), and younger ((mean ± SD) 58.6 ± 9 versus 64.3 ± 9.6 years (p < 0.0001)). Median (range) duration of follow‐up was 26.5 (11–54) months (insulin/metformin) versus 30 (15–58) months (insulin/sulphonylurea) (p = 0.1). Glycaemic control improved similarly with both regimens (mean ± SD—1.3 ± 1.7% (insulin/metformin) versus—1.4 ± 1.7% (insulin/sulphonylurea) (p = 0.5)); weight gain was less with insulin/metformin (4.0 ± 5.8 versus 6.1 ± 6.3 kg (p = 0.02)). Episodes of severe hypoglycaemia, ‘well‐being’ and ‘diabetes treatment satisfaction’ scores were similar.ConclusionFor patients with type 2 diabetes inadequately controlled with oral agents, insulin/metformin combination therapy appears superior to insulin/sulphonylurea, producing similar highly significant sustained improvements in glycaemic control but with less weight gain. Copyright © 2002 John Wiley & Sons, Ltd.