Intestinal glucose uptake is increased in aged mice.

Carbohydrate metabolism is impaired in the aged. Whether this is related to impaired glucose uptake or to other factors remains unclear. We measured changes in proliferative activity, glucose uptake, and disaccharidase activity in the intestinal mucosa of mice aged 2, 12, 24, and 30+ months to evaluate glucose absorption and its relationship to intestinal structure and proliferative activity. In vitro glucose uptake was increased significantly in the 30+ month-old mice compared to the younger animals. Similarly, crypt cell production rate and thymidine uptake were also increased. However, there were no significant changes in intestinal weight and length and villus height and crypt depth. These findings suggest that altered carbohydrate absorption in the aged is related to factors other than diminished mucosal glucose uptake. Whether this increased function is related to structural changes in the gut remains unclear.