Adequate Muscular Strength May Help to Reduce Risk of Residual-Specific Mortality: Findings From the National Health and Nutrition Examination Survey.

Abstract

Muscular strength has been shown to inversely associate with mortality. The purpose of this study was to examine the association between muscular strength and residual-specific mortality among a national sample of US adults, which has yet to be investigated. Here, residual-specific mortality is identified as deaths not inclusive of the 9 leading causes of death as identified by the International Classification of Diseases, 10th revision. Data from the 1999-2002 National Health and Nutrition Examination Survey were used (N = 2171 adults, aged 50-85 y). Participants were followed through 2011, including a median follow-up of 125 months. Lower extremity muscular strength was assessed using maximal isokinetic contractions. After adjusting for all covariates (age, gender, race/ethnicity, body mass index, C-reactive protein, mean arterial pressure, self-report of meeting aerobic-based physical activity guidelines, and physician diagnoses of diabetes), the Cox proportional hazard model demonstrated that for every 25 N increase in lower extremity muscular strength, individuals had a 14% reduced risk of residual-specific death (hazard ratio = 0.86; 95% confidence interval, 0.78-0.96; P = .008). Lower body muscular strength is inversely and independently associated with residual-specific mortality risk, underscoring the importance of adequate muscular strength to prolong survival.