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)

Authors: AZIZ, JASON - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY; REID, KIERAN - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY; BATSIS, JOHN - UNC GILLINGS SCHOOL OF GLOBAL PUBLIC HEALTH; FIELDING, ROGER - JEAN MAYER HUMAN NUTRITION RESEARCH CENTER ON AGING AT TUFTS UNIVERSITY

Submitted to: Journal of Aging Research & Lifestyle
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/19/2021
Publication Date: 4/7/2021
Citation: Aziz, J.J., Reid, K.F., Batsis, J.A., Fielding, R.A. 2021. 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). Journal of Aging Research & Lifestyle. 10:19-25. https://doi.org/10.14283/jarlife.2021.4.
DOI: https://doi.org/10.14283/jarlife.2021.4

Interpretive Summary: Older adults residing in rural regions of the United States were stronger compared to their urban counterparts. Researchers at JMUSDA-HNRCA conducted a study to examine urban-rural differences in the prevalence of sarcopenia indicators (grip weakness and slow walking speed). A secondary aim was to explore factors known to be associated with handgrip strength and walking speed. Data from the National Health and Nutrition Examination Survey (NHANES) was used to perform a cross-sectional analysis to evaluate urban-rural differences in the prevalence of grip weakness and slow walking speed in 2,923 participants over 60 years of age. Rural adults exhibited a lower prevalence of grip weakness (handgrip strength of < 35 kg. and < 20 kg., in men and women, respectively) and higher absolute grip strength (kg.), compared to urban adults. We also assessed relationships among factors known to be associated with sarcopenia (nutrition, physical activity, disease status). We found that total energy intake (kcal/day), was associated with higher grip strength. These data suggest that rural older adults are stronger compared to their urban counterparts, and that total caloric intake is associated with higher handgrip strength in older adults.

Technical 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(plus or minus 0.45) vs. 33.73(plus or minus 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.