Glucose clearance is delayed after hyperglycemia in healthy elderly men

Area of Science:

• Metabolism and Endocrinology
• Gerontology
• Cardiovascular Health

Background:

• Delayed glucose clearance post-hyperglycemia is a potential contributor to insulin resistance.
• Aging is associated with metabolic changes that may affect glucose regulation.
• Understanding glucose metabolism in healthy older adults is crucial for identifying early signs of metabolic dysfunction.

Purpose of the Study:

• To compare glucose and insulin decay rates after sustained hyperglycemia in healthy older versus younger men.
• To investigate the association between abdominal adiposity, lipid profiles, and glucose clearance in older men.

Main Methods:

• Sustained hyperglycemia (10 mmol/L) for 3 hours in 8 older (66±2 y) and 8 younger (22±1 y) healthy men.
• Measurement of fractional glucose clearance rates via regression analysis.
• Estimation of insulin decay and assessment of abdominal adiposity (waist-to-hip ratio) and lipid profiles.

Main Results:

• Older men exhibited significantly lower glucose clearance rates (1.9±0.2 vs. 2.9±0.1%/min) and higher post-hyperglycemia plasma insulin levels (P<0.03).
• Delayed glucose clearance in older adults correlated with increased abdominal adiposity (r=-0.56), higher triglycerides (r=-0.73), and elevated cholesterol (r=-0.56).
• Body weight and basal metabolic markers did not differ, but older men had higher fat mass and abdominal adiposity.

Conclusions:

• Clinically healthy older men demonstrate impaired glucose clearance associated with modest increases in abdominal adiposity and circulating lipids.
• These metabolic alterations may represent an early stage in the development of insulin resistance.
• This finding highlights a potential precursor to complications arising from prolonged postprandial hyperglycemia in aging populations.