OBJECTIVE: We conducted this study to assess the metabolic alterations in elderly patients with NIDDM. RESEARCH DESIGN AND METHODS: Healthy, lean (n = 15; age, 73 +/- 1 years; BMI, 23.8 +/- 0.5 kg/m2), and obese (n = 10; age, 71 +/- 1 years; BMI, 28.9 +/- 1.2 kg/m2) control subjects and lean (n = 10; age, 75 +/- 2 years; BMI, 24.0 +/- 0.5 kg/m2) and obese (n = 23; age, 73 +/- 1 years; BMI, 29.9 +/- 0.7 kg/m2) NIDDM patients underwent a 3-h glucose tolerance test, a 2-h hyperglycemic glucose clamp study, and a 3-h euglycemic glucose clamp study with tritiated glucose methodology to measure glucose production and disposal rates. RESULTS: Waist-to-hip ratio (WHR) was greater in both lean and obese NIDDM patients than in control subjects. Insulin responses during the oral glucose tolerance test were similar in obese subjects (control subjects: 417 +/- 64 pmol/l; NIDDM patients: 392 +/- 47 pmol/l) but were reduced in lean NIDDM patients (control subjects: 374 +/- 34 pmol/l; NIDDM patients: 217 +/- 20 pmol/l, P < 0.01). Lean and obese NIDDM patients had absent first-phase insulin responses during the hyperglycemic clamp. Second-phase insulin responses were reduced in lean (P < 0.01 vs. control subjects by analysis of variance) but not obese NIDDM patients. Hepatic glucose output was not increased in lean or obese NIDDM patients. Steady-state (150-180 min) glucose disposal rates were 16% less in lean NIDDM patients (control subjects: 8.93 +/- 0.37 mg.kg LBM (lean body mass)-1.min-1; NIDDM patients: 7.50 +/- 0.28 mg.kg LBM-1.min-1, P < 0.05) and 37% less in obese NIDDM patients (control subjects: 8.17 +/- 0.38 mg.kg LBM-1.min-1; NIDDM patients: 5.03 +/- 0.36 mg.kg LBM-1.min-1, P < 0.001). CONCLUSIONS: Lean elderly NIDDM patients have a profound impairment in glucose-induced insulin release but mild resistance to insulin-mediated glucose disposal. Obese elderly NIDDM patients have adequate circulating insulin, but marked resistance to insulin-mediated glucose disposal. Hepatic glucose output is not increased in elderly NIDDM patients.
OBJECTIVE: We conducted this study to assess the metabolic alterations in elderly patients with NIDDM. RESEARCH DESIGN AND METHODS: Healthy, lean (n = 15; age, 73 +/- 1 years; BMI, 23.8 +/- 0.5 kg/m2), and obese (n = 10; age, 71 +/- 1 years; BMI, 28.9 +/- 1.2 kg/m2) control subjects and lean (n = 10; age, 75 +/- 2 years; BMI, 24.0 +/- 0.5 kg/m2) and obese (n = 23; age, 73 +/- 1 years; BMI, 29.9 +/- 0.7 kg/m2) NIDDMpatients underwent a 3-h glucose tolerance test, a 2-h hyperglycemic glucose clamp study, and a 3-h euglycemic glucose clamp study with tritiated glucose methodology to measure glucose production and disposal rates. RESULTS: Waist-to-hip ratio (WHR) was greater in both lean and obese NIDDMpatients than in control subjects. Insulin responses during the oral glucose tolerance test were similar in obese subjects (control subjects: 417 +/- 64 pmol/l; NIDDMpatients: 392 +/- 47 pmol/l) but were reduced in lean NIDDMpatients (control subjects: 374 +/- 34 pmol/l; NIDDMpatients: 217 +/- 20 pmol/l, P < 0.01). Lean and obese NIDDMpatients had absent first-phase insulin responses during the hyperglycemic clamp. Second-phase insulin responses were reduced in lean (P < 0.01 vs. control subjects by analysis of variance) but not obese NIDDMpatients. Hepatic glucose output was not increased in lean or obese NIDDMpatients. Steady-state (150-180 min) glucose disposal rates were 16% less in lean NIDDMpatients (control subjects: 8.93 +/- 0.37 mg.kg LBM (lean body mass)-1.min-1; NIDDMpatients: 7.50 +/- 0.28 mg.kg LBM-1.min-1, P < 0.05) and 37% less in obese NIDDMpatients (control subjects: 8.17 +/- 0.38 mg.kg LBM-1.min-1; NIDDMpatients: 5.03 +/- 0.36 mg.kg LBM-1.min-1, P < 0.001). CONCLUSIONS: Lean elderly NIDDMpatients have a profound impairment in glucose-induced insulin release but mild resistance to insulin-mediated glucose disposal. Obese elderly NIDDMpatients have adequate circulating insulin, but marked resistance to insulin-mediated glucose disposal. Hepatic glucose output is not increased in elderly NIDDMpatients.
Authors: Fumiaki Imamura; Kenneth J Mukamal; James B Meigs; José A Luchsinger; Joachim H Ix; David S Siscovick; Dariush Mozaffarian Journal: Am J Epidemiol Date: 2013-05-24 Impact factor: 4.897