Age and glucose tolerance in healthy subjects

Area of Science:

• Gerontology
• Metabolic Science
• Endocrinology

Background:

• Metabolic alterations in aging are controversial.
• Previous studies showed comparable glucose disposal in elderly and young individuals.
• The specific impact of aging on beta-cell function requires further investigation.

Purpose of the Study:

• To investigate the effect of age on beta-cell secretion.
• To analyze C-peptide measurements in elderly versus young men.
• To assess age-related changes in glucose metabolism and insulin sensitivity.

Main Methods:

• Intravenous glucose tolerance test (0.3 g/kg) in ten elderly (70 yrs) and ten young (27 yrs) men.
• Analysis of C-peptide levels to assess beta-cell secretion.
• Minimal model analysis to quantify insulin sensitivity (SI) and glucose effectiveness (SG).

Main Results:

• Fasting glucose and insulin levels were not significantly different between groups.
• Insulin sensitivity (SI) and glucose effectiveness (SG) were unaltered by age.
• Elderly men exhibited systematically lower C-peptide levels compared to young controls (p < 0.005).

Conclusions:

• Aging does not affect glucose utilization or insulin sensitivity in healthy elderly men.
• Reduced C-peptide levels in the elderly suggest diminished beta-cell secretory capacity.
• These findings highlight potential age-related changes in insulin production independent of glucose metabolism efficiency.