Progressive Resistance Training can Improve the Metabolic Syndrome Phenotype in Older Adults

Abstract

Individuals diagnosed with metabolic syndrome are at increased risk for cardiovascular disease, type 2 diabetes, and the associated mortality. Exercise (muscle contraction) is often prescribed as a treatment for metabolic syndrome and associated insulin resistance as contraction-stimulated GLUT4 translocation results in improved glucose uptake to skeletal muscle. PURPOSE: We examined a sample of adults (n=67) for metabolic syndrome using established International Diabetes Federation (IDF) criteria. We tested the hypothesis that 16 weeks of progressive resistance training (PRT) would improve the metabolic syndrome phenotype in older adults. METHODS: Thirty older (64±1 yr, 14 men, 16 women) adults trained the lower limb musculature 3 days per week using knee extension, leg press, and squat. PRT consisted of 3 sets with an appropriate load for 8-12 repetitions to fatigue. Anthropometric measurements and three-day diet recalls were assessed by a registered dietician. Fasted morning blood samples were collected at baseline and after 16 weeks PRT for analysis of high-density lipoproteins (HDL-C), triglycerides, and circulating glucose. Body composition was measured by DEXA. RESULTS: Forty-seven percent of non-obese (BMI 26.4 ± 0.5) older adults exhibited the metabolic syndrome vs. 11% of non-obese (BMI 24.9 ± 0.5) young adults. Older adults with the metabolic syndrome were classified as such primarily due to abnormal waist circumference (100% of subjects), serum HDL-C levels (79%), and fasted glucose levels (86%). Also, 57% of metabolic syndrome subjects had elevated blood pressure and 36% abnormal triglyceride levels. After PRT, metabolic syndrome subjects showed a significant decline (P<0.001) in IDF positive criteria suggesting 16 weeks of PRT can improve the metabolic syndrome phenotype in older adults. The most frequent IDF category to show a training improvement was waist circumference. CONCLUSIONS: A progressive training program targeting lower limb musculature only is sufficient for stimulating metabolic adaptations and improving the metabolic syndrome phenotype in older adults. Support: R01 AG017896 and VA Merit.