QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Krishnan, R. K. Articles by Kirwan, J. P. Search for Related Content PubMed PubMed Citation Articles by Krishnan, R. K. Articles by Kirwan, J. P.

---

Nutrition and Aging
Research Communication

Glucose Clearance Is Delayed after Hyperglycemia in Healthy Elderly Men

Raj K. Krishnan, William J. Evans^* and John P. Kirwan^,2

Noll Physiological Research Center, Penn State University, University Park, PA 16802; ^* Nutrition, Metabolism, and Exercise Division, University of Arkansas for Medical Sciences, Little Rock, AR 72114; and Departments of Reproductive Biology and Nutrition, Case Western Reserve University School of Medicine at MetroHealth Medical Center, Cleveland, OH 44109

²To whom correspondence should be addressed. E-mail: jpk10{at}cwru.edu.

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.

KEY WORDS: • aging • obesity • diabetes • insulin resistance