Combined exercise is a modality for improving insulin resistance and aging-related hormone biomarkers in elderly Korean women

Abstract

Background: The functional decline of the endocrine and immune systems with aging causes changes in the regulation of the body's metabolism and defense functions. Although it is impossible to stop aging artificially, regular exercises reportedly delay aging and have positive effects on senile diseases. The improvements in insulin resistance values and aging-related hormones in elderly women after combined exercises have not been effectively elucidated.

Objective: In this study, we aimed to examine the impact of combined exercise on insulin resistance and aging-related hormones in elderly women.

Methods: Twenty elderly Korean women were randomly assigned to a "non-exercise" (n = 10) or combined exercise group (n = 10). The exercise group performed both anaerobic and aerobic exercises for 12 weeks, three times per week. Exercise intensity was increased gradually, from 40% to 70% of the heart rate reserve (HRR) every 3 weeks. Insulin resistance, growth hormone, IGF-1, DHEA-S, and estrogen were measured before and after the 12-week intervention.

Results: The main effect was found in the glucose level for a time, which significantly decreased in the exercise group. The insulin level and HOMA-IR showed significant interaction effects and increased significantly in the control group. The GH level showed significant interaction effects and increased significantly in the exercise group. The IGF-1 level showed significant interaction effects, but not significantly within and between groups. The DHEA-S level revealed interaction effects and the main effect for a time and significantly increased in the exercise group. The estrogen level exhibited an interaction effect and increased significantly in the exercise group. After the 12-week combined exercise intervention, no significant difference was observed between groups.

Discussion: This study has shown that 12-week combined exercise is useful for improving insulin resistance and GH, IGF-1, and DHEA-S levels in elderly women. Thus, this study provides evidence that combined exercise is a useful therapeutic method to decrease insulin resistance and stimulate the secretion of aging-related hormones in elderly women.

Keywords: Combined exercise; DHEA-S; Estrogen; GH; IGF-1; Insulin resistance.