Abstract

• To evaluate whether the urinary and serum c-peptide is the indicator of insulin therapy in NIDDM, and whether the insulin secretery capacity improves after control of blood glucose, We measured 24 hour urinary c-peptide excretion, fasting and postprandial 2hour's serum c-peptide concentrations before and after insulin therapy in 20 patients with NIDDM.
  The results were as follows ;
  1) The postprandial 2 hour's serum c-peptide level was significantly lower in patients with NIDDM than normal controls, bu t fasting serum c-peptide level and 24hour urinary c-peptide excretion showed no significant difference between normal control group and patients with NIDDM
  2) There was no significant difference in duration of disease, body mass index, fasting serum c-peptide level and 24 hour urinary c-peptide excretion between insulin-requiring group and non-insulin-requiring group among patients with NIDDM. But post prandial 2 hour's serum c-peptide level was significantly lower in insulin requiring group than non-insulin-requiring group before treatment.
  3) After therapy with insulin, post prandial 2 hour's serum c-peptide level increased significantly in insulin requiring group, but fasting serum c-peptide and 24 hour urinary c-peptide excretion were not changed significantly after therapy with insulin comparing with the level before therapy.
  Author concluded that postprandial 2 hour's serum c-peptide level was a market of insulin therapy in patients with NIDDM and insulin secretory capacity improved after controlling of blood glucose.