The Study On Insulin Secretion And Insulin Action In Obese Diabetic Patients With Unprovoked Ketosis

Objective: To evaluate the peripheral insulin sensitivity and pancreatic β cell insulin secretion function in obese diabetic patients with unprovoked ketosis , and to explore the possible mechanism of unprovoked ketosis in obese diabetic subjects.Subjects and methods: 10 obese diabetic patients [all men, age: 43 (21 — 60) , body mass index: 25.71 (20.89-29.76) kg/m~2; WHR:0.97 (0.89-1.04)] with unprovoked ketosis were involved in this study. Each subject underwent an euglycemic-hyperinsulinemic clamp to measure glucose deposal rate (GDR).Intravenous glucose tolerance test (IVGTT) and hyperglyccmic clamp was performed on 4 subjects to evaluate the acute insulin response (AIR), second-phase insulin response (2ndIR), and glucose infusion rate (M).Serum insulin, C peptide, free fatty acids (FFAs) and β hydroxybutyric acid levels were also measured in all patients. Results: The GDR during steady state of euglycemic-hyperinsulinemic clamp was very low in all subjects [5.03 (1.85—6.43) mg/Kg.min] .Acute insulin response were lack in 3 subjects at presentation and it was partly improved in 1 subject after 3months treatment.The second-phase insulin response were also very low during the onset of illness(1.63μU/ml,12.92/iU/mh 10.21/tU/ml) and it was increased to 32.42/iU/ml after treatment. The glucose infusion rate during hyperglycemic clamp were also very low in the patients of the onset of illness(0.49~1.64 mg/Kg.min ),and increased to 3.97 mg/Kg.min after treatment. Compaired with normal control, obesity ,diabetes and IGT patients, ketotic patients had higher serum FFAs level. The increase of FFAs demonstrated positive correlation with the ketogenesis,which approached statistical significance (r=0.863, P=0.001). Conclusions: Severely peripheral insulin resistance and impaired /3-cell insulin secretion were abserved in obese diabetic patients with unprovoked ketosis, and the impaired /3-cell insulin secretion were partly improved when the blood glucose was controled after 3 months treatment. It is logical to expect that these diabetic patients may belong to type 2 diabetes.