Exercise Improves Insulin Secretion & Sensitivity In The Elderly

A new study, presented in the Journal of Clinical Endocrinology & Metabolism, has found that elderly people with either diabetes or impaired glucose tolerance (a precursor to diabetes) , dramatically improved their sensitivity to insulin after just one week of light aerobic exercise.

The research, conducted at the Department of Internal Medicine at the University of Michigan, involved 12 elderly people with impaired glucose tolerance (IGT) performing an hour of supervised aerobic exercise for a period of 7 days. The exercise consisted of sessions on either a treadmill, cross training machine, or exercise bike with participants working at between 60 and 70 percent of their maximum heart rate capacity.

A frequently sampled IV glucose tolerance test (FSIGT) was administered to each individual prior to the beginning of the exercise regime and again 24 hours after the final exercise session.

The research, carried out by Cathie J. Bloem and Annette M. Chang, found that the exercise regime improved insulin sensitivity increased by an impressive 59 percent while beta-cell function increased by 31 percent. Beta-cells are located in the pancreas and are responsible for insulin secretion in response to blood glucose spikes.

Diabetes and IGT are significant health problems for elderly people because as a person ages, they both secrete less insulin and become less sensitive to the insulin they do secrete. While other studies have shown that exercise improves insulin sensitivity, it had not been clear until now whether exercise also increased the ability of beta cells to secrete insulin.

The prevalence of IGT or diabetes in individuals over 65 years of age is thought to be around 34 percent for men and 38 percent for women. Among overweight elderly individuals the prevalence of abnormal glucose tolerance is even greater with over half of all overweight elderly people suffering from IGT or diabetes.