Long-Term Improvement of Glycemic Control by Insulin Treatment in NIDDM Patients With Secondary Failure

Abstract

OBJECTIVE To evaluate the long-term efficacy of insulin treatment of patients with non-insulin-dependent diabetes mellitus (NIDDM) and secondary failure to oral hypoglycemic agents. RESEARCH DESIGN AND METHODS Twenty one NIDDM patients with secondary failure were studied while they were still on oral agents. Then they were switched to insulin treatment, and after a median of 27 months, a long-term evaluation was conducted. RESULTS At the long-term evaluation, metabolic control was still markedly improved by insulin treatment, with reduction of HbA1c from 8.8 ± 0.2 (mean ± SE) to 6.9 ± 0.3% (P < 0.0001), lowering of very-low-density lipoprotein (VLDL) cholesterol concentration from 0.97 ± 0.3 to 0.69 ± 0.1 mM (P < 0.03), and lowering of total triglycerides from 2.8 ± 0.6 to 1.8 ± 0.3 mM (P < 0.005), mainly due to reduction of VLDL triglycerides. Body weight increased during the first year, but not thereafter (71.3 ± 2.5 kg during oral treatment, 78.9 ± 2.9 and 79.8 ± 3.2 kg after 12 and 36 months of insulin treatment, respectively). Blood pressure did not change. Fasting and postprandial insulin concentrations increased, and C-peptide concentrations were lowered. CONCLUSIONS Improvements of glycemic control and lipoprotein concentrations in patients with NIDDM and secondary failure persist also after insulin treatment for 2–3 years in spite of weight gain and hyperinsulinemia.