RESUMEN
BACKGROUND: Non-steroidal anti-inflammatory drugs (NSAIDs) may enhance resistance training induced gain in skeletal muscle mass and strength, but it is unknown if NSAIDs affects muscle loss during periods of inactivity in elderly individuals. Thus, we studied the influence of NSAID treatment on human skeletal muscle during immobilization and rehabilitation resistance training (retraining). METHODS: 19 men (60-80yrs, range) were randomly assigned to ibuprofen (1200mg/d, Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2weeks and retrained for 6weeks. Moreover, whey protein isolate was ingested (2×20g/d) throughout the whole study period. Plasma inflammatory markers, quadriceps muscle mass and strength, and muscle gene expression were investigated. RESULTS: Muscle mass and strength decreased after 2weeks of immobilization (P<0.001), but returned to baseline levels after 2weeks of retraining combined with whey protein supplementation (P<0.001). Furthermore, muscle mass and strength reached beyond baseline levels after 6weeks of retraining (p<0.05), and NSAID did not significantly affect this (p>0.05). No group-differences, but differences over time, were observed for muscle gene expression of proteolytic and anabolic factors. Plasma inflammatory markers were unaffected by the study intervention and NSAID treatment. CONCLUSION: Two weeks of lower limb immobilization lead to a reduction in muscle mass and strength, but these parameters were restored already after2 weeks of retraining and whey protein supplementation. After 6weeks of retraining and whey protein supplementation, muscle mass and strength increased beyond baseline levels, and NSAID treatment did not significantly influence this in elderly.