Residual B Cell Function in Patients with Long-Standing NIDDM and Its Relation to Metabolic Control and Diabetic Complications

Abstract

We have evaluated the residual pancreatic B cell function by glucagon load test in 28 patients with non-insulin-dependent diabetes mellitus (NIDDM) of a duration of 20 years or more. The increase in serum C-peptide at 6 minutes after glucagon administration (C-peptide) was used as an index of residual B cell function. There was much lessΔC-peptide in patients treated with insulin than in those treated with sulfonylurea (p<0.05), and it was significantly correlated with the body mass index (r=0.40, p<0.05). Long term metabolic control assessed by the average annual mean fasting blood glucose for the observation period (mean, 21 years) was not correlated with ΔC-peptide (r=-0.13). The prevalence of retinopathy which needed photocoagulation therapy and of neuropathy in ptaients with poor residual B cell function (ΔC-peptide≦0.3ng/ml) was the same as that in those with good residual B cell function (ΔC-peptide≧1.0ng/ml). The present study shows that the residual B cell function is not correlated with long term glycemic control and the prevalence of diabetic complications in long-standing NIDDM patients. © 1988, The Japan Endocrine Society. All rights reserved.