Lower Muscle Strength Gains in Older Men with Newly Diagnosed NIDDM After a Resistance Training

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Disability is two to three times higher among older people with diabetes than among those without diabetes. This is related with the fact that in older men with NIDDM declines in the functional capacity of the neuromuscular and neuroendocrine systems are increased with regard to the observed in healthy older men. On the other hand, exercise interventions that improve neuromuscular performance in older people are becoming recognized as an effective strategy against disability, increasing functional independence. PURPOSE: To determine if a twice- weekly whole body supervised- progressive resistance training (PRT) program is effective in neuromuscular (maximal strength and power output) and endocrine adaptations in newly diagnosed older men with NIDDM as it has been shown in healthy ones. METHODS: Eleven healthy and ten newly diagnosed NIDDM subjects completed 2 times per week a 16-week period of supervised PRT at intensities of 50–80% of one repetition concentric maximum (1-RM). Lower and upper body maximal strength and muscle power output were assessed using 1-RM action and a 30% of their respective 1- RM in a half-squat and in a bench-press position, respectively. Resting serum total testosterone (T), free testosterone (fT) and cortisol (C) were determined by radio immuno ass ays. RESULTS: Baseline maximal voluntary arm and leg strength was not significantly different between healthy and NIDDM groups (47.8 ± 12.4 vs. 45.9 ± 6.5 Kg; and 103.1 ± 25.9 vs. 106.3 ± 8.3 Kg, respectively). After training, the increase in arm and leg strength in NIDDM subjects (24.2 ± 4.1% and 17.0 ± 3.8%, respectively) was significantly smaller (P < 0.05–0.01) than that recorded in the control healthy group (36.7 ± 12.9% and 35.6 ± 12.2%, respectively). During the 16-wk training period the increases in power of the arm and leg extensors muscles were similar in both groups tested (22.5 ± 21.3 vs. 23.8 ± 18.3%, n.s.; and 34.2 ± 32.0 vs. 33.0 ± 21.2%, n.s., respectively). Significant linear correlations were observed in a combined group of healthy plus older men with NIDDM between both the mean level of individual serum total T and C concentrations (averaged for the entire training period) and the individual changes in 1-RM of the leg (r= 0.85 and 0.51; P < 0.05, respectively) and arm muscles (r= 0.63 and 0.70; P < 0.05, respectively). CONCLUSIONS: In NIDDM, PRT leads to a similar muscle power increase but to a smaller strength gains than in healthy older men. Collectivelly, these observations suggest that the partial androgen deficiency should play a key role in strength gains in these patients.