Dysmobility syndrome and mortality risk in US men and women age 50 years and older

Abstract

Summary: Mortality risk was significantly elevated in older adults from NHANES 1999–2002 with dysmobility syndrome. Introduction: Dysmobility syndrome was recently proposed as an approach to evaluate the musculoskeletal health of older persons, but data linking this syndrome to adverse outcomes are currently lacking. The present study used data from the National Health and Nutrition Examination Survey (NHANES) 1999–2002 to assess the relationship between dysmobility and mortality in adults age 50 years and older by age, sex, and race or ethnicity. Methods: Dysmobility was defined as three or more of the following: high body fat, osteoporosis, low muscle mass, low muscle strength, slow gait speed, or falling risk. Body composition and bone density were assessed with dual energy X-ray absorptiometry. Gait speed was measured via a timed walk, muscle strength via isokinetic knee extension, and fall risk via self-reported balance problems in the past year. Hazard ratios (HRs) for mortality were calculated with Cox proportional hazard models. Results: Twenty-two percent of adults age 50+ years had dysmobility in 1999–2002. Mortality risk by dysmobility varied significantly by age (pinteraction = 0.001). HRs for those aged 50–69 years were 3.63 (95 % confidence interval (CI) 2.69, 4.90) and 2.59 (95 % CI 1.82, 3.69), respectively, before and after adjusting for all confounders, compared with 1.46 (95 % CI 1.07, 1.99) and 1.23 (95 % CI 0.89, 1.69) for those aged 70+ years. The relationship was significant when examined by sex or race/ethnicity within age group for most subgroups. Conclusions: Dysmobility was associated with increased mortality risk in adults age 50 years and older, with risk being higher in those age 50–69 years than in those age 70+ years.