Carbohydrate (CHO) oxidation in patients with type B insulin resistance.
Total body carbohydrate (CHO) and fat oxidation rates, plasma glucose, free fatty acid, and insulin concentrations were determined in two patients with the type B syndrome of severe insulin resistance and in normal controls in response to insulin infusions (1-100 mU/kg/min) and to a test meal. In addition, insulin was infused at higher rates (10-1000 mU/kg/min) in one of the two patients while plasma glucose concentrations were clamped first at 195 and later at 244 mg/dl. During the postabsorptive state, resting metabolic rates (RMR) were 914 and 979 cal/min/1.73 m2 in the two patients (controls: 1018 +/- 85 cal/min/1.73 m2). Patients met 85% and 83% of their caloric requirements by oxidizing fat (controls: 63 +/- 7%). Protein oxidation accounted for 15% and 13% (controls: 14 +/- 3%) of energy requirements and CHO oxidation for 0% and 0%, respectively, in both patients (controls: 23 +/- 5%). Infusion of insulin at a rate of 10 mU/kg/min raised plasma insulin concentrations from 1400 and 440 microU/ml to 6000 and 2500 microU/ml, respectively, in patients 1 and 2 (controls: from 4 +/- 0.3 to 1288 +/- 50 microU/ml), but had no effects on rates of CHO, fat, or protein oxidation in either patient. By comparison, the rate of CHO oxidation in controls rose about sixfold from 40 +/- 8 to 234 +/- 12 mg/min/1.73 m2. Infusion of 1000 mU/kg/min in combination with an increase in plasma glucose from 195 +/- 1.1 to 244 +/- 1.9 mg/dl in patient 1, however, raised CHO oxidation from 0 to 36 mg/min/1.73 m2 and lowered fat oxidation from 105 to 69 mg/min/1.73 m2.(ABSTRACT TRUNCATED AT 250 WORDS)
D000052:Acanthosis Nigricans / Q000150:complications / Q000378:metabolism; D000328:Adult; D001692:Biological Transport; D001786:Blood Glucose / Q000502:physiology; D050260:Carbohydrate Metabolism; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000378:metabolism; D005223:Fats / Q000378:metabolism; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005502:Food; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance; D007592:Joint Diseases / Q000150:complications / Q000378:metabolism; D008297:Male; D008660:Metabolism / Q000187:drug effects; D010084:Oxidation-Reduction; D011659:Pulmonary Gas Exchange
D001786:Blood Glucose; D005223:Fats; D005230:Fatty Acids, Nonesterified; D007328:Insulin