Significance of spontaneous ketonuria and serum C-peptide levels in obese type II diabetic patients.
Patients with type II diabetes mellitus (type II DM patients) are characteristically obese, hyperinsulinemic, and non-ketosis prone. Recently, we have encountered several obese type II DM patients with either diabetic ketoacidosis or significant ketonuria after insulin withdrawal. There was no evidence of infection, stress, or starvation to explain their ketonuria. Therefore, we assessed serum connecting peptide (C-peptide) response to oral glucose in 14 obese, insulin-treated type II DM patients: 6 with and 8 without episodes of spontaneous ketonuria. The group presenting with ketonuria had low to absent basal and stimulated serum C-peptide responses. The nonketonuric group had higher basal C-peptide (P less than 0.01) concentrations that increased significantly (P less than 0.001) after oral glucose compared with those of the ketonuric group. Clinical characteristics and biochemical control were similar in both groups. Our findings confirm that obese type II diabetes mellitus is a heterogeneous disease with variable fasting and stimulated C-peptide responses. Spontaneous ketonuria could be a feature in the clinical presentation of the patients especially in the presence of both low fasting and stimulated C-peptide levels. The significance of these findings is unclear but suggests individualization in the management of type II DM patients and cautious withdrawal of insulin therapy in such patients. Furthermore, serum C-peptide levels alone cannot be recommended to classify patients into either type I or type II diabetes mellitus.
D000368:Aged; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood*; D003920:Diabetes Mellitus / Q000188:drug therapy / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000378:metabolism*; D005260:Female; D006801:Humans; D007328:Insulin / Q000009:adverse effects / Q000627:therapeutic use; D007657:Ketone Bodies / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009765:Obesity; D013375:Substance Withdrawal Syndrome / Q000652:urine
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D007657:Ketone Bodies