Combination-therapy with bedtime nph insulin and sulphonylureas gives similar glycaemic control but lower weight gain than insulin twice daily in patients with type 2 diabetes.

BACKGROUND

To study the effect on body weight and glycaemic control of two insulin treatment regimens in patients with Type 2 diabetes and moderate failure to oral hypoglycaemic agents.

METHODS

Sixteen patients treated with oral hypoglycaemic agents (6 men and 10 women) were included in this open-label, randomized, parallel group study. Their age was 62 +/- 2 (mean +/- SEM) years (range 44-79 years), body weight 71.3 +/- 2.9 kg, body mass index (BMI) 24.6 +/- 0.8 kg/m(2). The patients were switched to insulin treatment with bedtime NPH insulin combined with daytime sulphonylurea (combination group) or twice daily injections of a premixed combination of regular human and NPH insulin (insulin twice daily group) with measurements as given below before and after 12 and 24 weeks of treatment.

RESULTS

HbA(1c) was lowered from 8.3 +/- 0.3% to 7.0 +/- 0.2% in the insulin twice daily group (p<0.05) and from 8.3 +/- 0.3% to 6.8 +/- 0.5% in the combination group (p<0.03; ns between treatment groups). Body weight increased from 71.7 +/- 4.0 kg to 77.6 +/- 4.4 kg in the insulin twice daily group (p<0.001) and from 70.8 +/- 4.6 kg to 72.7 +/- 5.1 kg in the combination group (ns; p<0.02 between groups). The dose of insulin at 24 weeks in the insulin twice daily group was 45.8 +/- 4.2 U and 29.4 +/- 5.4 U in the combination group (p=0.03). Combination treatment reduced fasting and stimulated C-peptide levels.

CONCLUSIONS

Both treatments improved glycaemic control to the same extent but the combination of bedtime NPH insulin and daytime sulphonylurea gave a very small increase of body weight over a 6 months period. We conclude that combination therapy is an attractive alternative when starting insulin treatment in patients with Type 2 diabetes as this is a critical period for weight gain in such patients.