Urban-rural differences in the prevalence of muscle weakness and slow gait speed: A cross-sectional analysis from the NHANES (2001-2002 and 2011-2014)

Abstract

Background: Older adults living in rural areas suffer from health inequities compared to their urban counterparts. These include comorbidity burden, poor diet, and physical inactivity, which are also risk factors for sarcopenia, for which muscle weakness and slow gait speed are domains. To date, no study has examined urban-rural differences in the prevalence of muscle weakness and slow gait speed in older adults living in the United States. Objective: To compare the prevalence of grip strength weakness and slow gait speed between urban and rural older adults living in the United States. Design: A cross-sectional, secondary data analysis of two cohorts from the National Health and Nutrition Examination Survey (NHANES), using gait speed or grip strength data, and urban-rural residency, dietary, examination, questionnaire and demographic data. Participants: 2,923 adults (≥ 60 yrs.). Measures: Grip weakness was defined as either, an absolute grip strength of <35 kg. and <20 kg. or grip strength divided by body mass index (GripBMI) of <1.05 and <0.79 for men and women, respectively. Slow gait speed was defined as a usual gait speed of ≤0.8m/s. Results: The prevalence of GripBMI weakness was significantly higher in urban compared to rural participants (27.4% vs. 19.2%; p=0.001), whereas their absolute grip strength was lower (31.75(±0.45) vs. 33.73(±0.48)). No urban-rural differences in gait speed were observed. Conclusions: Older adults residing in urban regions of the United States were weaker compared to their rural counterparts. This report is the first to describe urban-rural differences in handgrip strength and slow gait speed in older adults living in the United States.