NHANES Grip Test Measured Muscular Strength of American Adults

Abstract

PURPOSE: The isometric grip test is a simple measure of muscle strength that was recently added to the National Health and Nutrition Examination Survey (NHANES). Previous research has shown an inverse relationship between grip strength and cardiovascular mortality. Since grip strength in an American population-based study has never been reported, this study describes grip strength in American adults by demographics, obesity category, and physical activity (PA) level. METHODS: Adults (n= 4252) completed the 2011-2012 NHANES’ body measure, grip test, demographic and physical activity questionnaires. Data were analyzed via SAS 9.4 SURVEY procedures using NHANES analytic guidelines. RESULTS: Over 35% of American adults were obese (body mass index > 30 kg/m2); 55.07% were viscerally obese (sagittal abdominal diameter >22 cm for male, and >20 cm for female). Males (42.73 ± 0.36 kg) demonstrated significantly stronger grip strength than females (26.83 ± 0.17 kg) (p<0.0001). Adults 20-39y had significantly stronger grip strength than those 40-59y (p=0.0008) and 60+ y (p<0.0001), and adults 40-59y had stronger grip strength than those 60+y (p<0.0001). Non-Hispanic Blacks (NHB) had stronger grip strength than non-Hispanic Whites (NHW, p=0.003), Hispanics (H; p<0.0024) and Non-Hispanic Asians (NHA, p<0.0001), and both NHW and H had stronger grip strength than NHA (p<0.0001). There was no difference between grip strength of NHW and H (p=0.99). High income adults had significantly stronger grip strength than those classified as low (p=0.01) or middle income (p=0.038). Adults with less than high school education had weaker grip strength than those with high school (p=0.043) or college education (p=0.004). Obese adults had stronger grip strength than non-obese adults (p=0.0004), and viscerally obese adults had stronger grip strength than those not viscerally obese (p=0.016). Adults who reported no moderate-to-vigorous leisure-time physical activity (MVLTPA) participation had significantly weaker grip strength than those who reported MVLTPA participation (p=0.0006). CONCLUSIONS: Grip strength varies by demographics, obesity category, and PA level. Future research is needed to link grip strength to other risk factors (e.g., dietary patterns) and health conditions in American adult population.