EFFECTS OF HIGH-INTENSITY RESISTANCE TRAINING AND DIET ON GLYCEMIC CONTROL IN OLDER PERSONS WITH TYPE 2 DIABETES

Abstract

The typical recommendation to combine endurance-type exercise with diet may be compromised in older persons with Type 2 diabetes because of the normal age-related decline in muscle strength and function. Resistance training (RT) may offer a plausible alternative because of its known effects on muscle strength, size and function. It may also compliment weight loss through the preservation, or increase, in lean body mass (LBM). The aim of this study was to investigate the long-term effects of high-intensity RT combined with moderate energy restriction on glycemic control and body composition in older persons with Type 2 diabetes. We studied 28 overweight (BMI > 27 kg/m2), sedentary men and women (mean age ± SE: 67.1 ± 1.0 yrs) with established (> 6 mo) Type 2 diabetes. Participants were randomised to either: 1) RT (3/wk, 3 sets/[email protected]–85% 1RM with moderate energy restriction (RT+Diet - n = 17), or 2) placebo exercise (stretching, 3/wk) with moderate energy restriction (Diet - n = 11). A third non-randomised group served as controls (n = 11). Body mass (BM), muscle strength, HbA1c, LBM and fat mass (FM) (measured by DXA) were measured at baseline and after 6 months. No significant differences were observed between the groups at baseline. The mean exercise attendance was 95% and 84% for the RT+Diet and Diet groups respectively. Muscle strength for all exercises improved significantly after RT. Although moderate decreases in BM and FM were observed for both the RT+Diet and Diet groups, the only intergroup difference detected was the ΔFM between the RT+Diet and controls after 6 months. There were no significant changes in LBM. A 14.7% reduction in HbA1c from baseline observed following RT (−1.21 ± 0.2%) was significant (p < 0.05) compared to both the Diet (−0.5 ± 0.3) and Control (−0.1 ± 0.3) groups. These observations remained significant after adjustment for fat mass changes. These findings show that high-intensity resistance training can lead to improved muscle strength and glycemic control in older persons with Type 2 diabetes and when combined with moderate energy restriction may offer an effective lifestyle management strategy.