The Physiological Significance of the Glucose Intolerance of Aging

: Aging is associated with glucose intolerance, but its significance is unclear. We performed oral glucose tolerance tests and more physiologic meal tolerance tests in a group of 23 young adults, mean (+/- SE) age, 37 +/- 2 years and 17 elderly adults, mean age 69 +/- 1 years. The total glucose and insulin responses following the oral glucose load were increased by 24% and 127% respectively in the elderly compared with the young (24,524 +/- 1,080 vs. 19,734 +/- 702 mg/dl X min and 24,289 +/- 3,401 vs. 10,700 +/- 1,209 microU/ml X min). Following mixed meals, the total glucose response was 45,795 +/- 1,343 mg/dl X min in the young, compared with 50,998 +/- 1,850 mg/dl X min in the elderly (p less than .05) an 11% increase. Total insulin response was increased by 40% in the elderly (38,590 +/- 3,662 microU/ml X min) compared with the young (27,481 +/- 2,805 microU/ml X min) (p less than .05). We conclude that following the ingestion of more physiologic mixed meals, modest postprandial hyperglycemia and hyperinsulinemia can be demonstrated in elderly adults.