Depressive symptoms, handgrip strength, and weight status in US older adults

Background: Handgrip strength is a valid indicator of broader physical functioning. Handgrip strength and weight status have been independently associated with depressive symptoms in older adults, but no study has yet investigated the relationships between all three in older US adults. This study investigated the relationship between physical function and depressive symptoms by weight status in older US adults. Methods: Cross-sectional data were analysed from the National Health and Nutrition Examination Survey waves 2011 to 2012 and 2013 to 2014. Physical function was assessed using a grip strength dynamometer. Depressive symptoms were assessed using the self-reported Patient Health Questionnaire-9. Weight status was assessed using Body Mass Index (BMI) and participants were categorised as normal weight (<25 kg/m2), overweight (25 to <30 kg/m2), and obese (≥30.0 kg/m2). Associations between depressive symptoms and hand grip strength were estimated by gender-specific multiple linear regressions and BMI stratified multivariable linear regression. Results: A total of 2,812 adults (54% female, mean age 69.2 years, mean BMI 29.2 kg/m2) were included. Women with moderate to severe depressive symptoms had 1.60 kg (95% CI: 0.91 to 2.30) lower hand grip strength compared to women with minimal or no depressive symptoms. No such association was observed in men. Among those with obesity, men (-3.72 kg, 95% CI: -7.00 to -0.43) and women (-1.83 kg, 95% CI: -2.87 to -0.78) with moderate to severe depressive symptoms both had lower handgrip strength. Conclusion: Among older US adults, women and people who are obese and depressed are at the greatest risk of decline in physical function.