title: Glucose clearance is delayed after hyperglycemia in healthy elderly men.
abstract: Delayed glucose clearance after hyperglycemia may contribute to insulin resistance. Rates of glucose and insulin decay were measured after 3 h of sustained hyperglycemia (10 mmol/L) in 8 healthy older men (66 +/- 2 y) and were compared with those of 8 younger men (22 +/- 1 y). Fractional glucose clearance rates were calculated by regression analysis. Insulin decay was estimated from insulin levels through 30 min postinfusion. Abdominal adiposity was estimated from waist-to-hip ratios. Body weight and basal plasma glucose, insulin and C-peptide concentrations did not differ between groups. Fat mass, abdominal adiposity, fasting serum triglycerides and total cholesterol, although normal, were higher (P < 0.05) in the older group. The elderly group experienced lower glucose clearance rates (1.9 +/- 0.2 vs. 2.9 +/- 0.1%/min, P < 0.002) and higher plasma insulin after hyperglycemia (P < 0.03). Glucose and insulin decay correlated with glucose infusion rates (r = 0.88, P < 0.0002 and r = 0.51, P < 0.05). Delayed glucose clearance was associated with greater abdominal adiposity (r = -0.56, P < 0.03), higher serum triglycerides (r = -0.73, P < 0.003) and elevated serum cholesterol (r = -0.56, P < 0.04). In conclusion, modest increases in abdominal adiposity and circulating lipids are associated with abnormal glucose clearance in clinically healthy older men; this may be a precursor to the development of insulin resistance and related complications that arise from prolonged postprandial hyperglycemia.
authors.affiliation: Noll Physiological Research Center, Penn State University, University Park, PA 16802, USA.
authors.forename: Raj K
authors.initials: RK
authors.lastname: Krishnan
authors.forename: William J
authors.initials: WJ
authors.lastname: Evans
authors.forename: John P
authors.initials: JP
authors.lastname: Kirwan
mesh_terms: D000328:Adult; D000368:Aged; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged
chemical_list: D005947:Glucose