The Effect of Insulin Treatment on HbA_1c, Body Weight and Lipids in Type 2 Diabetic Patients with Secondary-Failure to Sulfonylureas.

Summary

No conclusive data are available about the long-term effect of insulin treatment in type 2 diabetic patients failing to maximal doses of sulfonylureas and caloric restriction. In total 160 non-obese type 2 diabetic patients with secondary failure were substituted with insulin using a diabetic teaching and care program. From these 160 patients 40 died within the observation period of five years; 102 patients had a complete five year follow-up, whereas the remaining 18 patients did not come to regular follow-up visits. Metabolic control parameters improved significantly in the 102 patients with the complete five year follow-up. Postprandial plasma glucose (16.0 mM vs 10.9 mM; p < 0.0001) and HbA_1c values (8.7 % vs 7.1 %, p < 0.0001) decreased significantly from the state before to five years after insulin substitution. In addition, plasma lipid levels could be significantly lowered under insulin therapy (cholesterol 6.2±1.5 mM vs 5.4±3.6 mM, p < 0.0002; triglycerides 2.8±1.6 mM vs 2.4±2.1 mM, p < 0.01). However, we observed a significant weight gain (mean: 10.6 kg) associated with insulin application during the five year follow-up. Thus, the body-mass-index decreased from 28.9 at onset of type 2 diabetes to 24.5 (p < 0.0001) at time of secondary failure and increased again to 28.5 (p < 0.0001) at five years after onset of insulin treatment. Furthermore, small increases of plasma creatinine from 88.4 μM to 115 μM, as well as systolic (19.3 kPa to 20.7 kPa) and diastolic (10.7 kPa to 11.3 kPa) blood pressures were observed.

In summary, insulin therapy over five years resulted in a long lasting improvement of metabolic long-term control in the majority of type 2 diabetic patients who were non-obese at the time of secondary failure to sulfonylurea treatment. The weight gain associated with insulin therapy and the high mortality rate due to the progressed state of the disease as documented in this study remain to be major problems in this particular group of type 2 diabetic patients.

Key words

Type 2 Diabetes - Secondary Failure - Insulin Therapy - Sulfonylurea