The association of grip strength with depressive symptoms and cortisol in hair: A cross‐sectional study of older adults

Abstract

Background Low handgrip strength has been shown to be associated with higher levels of depressive symptoms. One area of mental health that is understudied in relation to grip strength is chronic stress, which can exist independently to depression, or as a comorbidity or precursor to this condition. The present study examined cross‐sectional associations between grip strength, an established marker of physical function, and (a) depressive symptoms and (b) chronic stress utilizing hair cortisol concentrations, while accounting for multiple pertinent confounding variables. Method Data were used from wave 6 (2012/13) of the English Longitudinal Study of Aging, a panel study of older (≥50 years) community‐dwelling men and women. Grip strength was measured in kg using a hand‐held dynamometer. Depressive symptoms were assessed using the 8‐item Center for Epidemiologic Studies Depression scale. Hair cortisol concentrations (pg/mg) were determined from samples of scalp hair and log‐transformed for analysis to correct skewness. Associations of grip strength with depressive symptoms and hair cortisol concentration were tested using linear regression models adjusted for age, sex, ethnicity, wealth, smoking status, physical activity, body mass index, limiting long‐standing illness, arthritis, diabetes, and hair treatment. Results The sample comprised of 3741 participants (mean age 68.4 years, 66.4% female). After adjustment for age and sex, grip strength was significantly and negatively associated with both depressive symptoms (B = −0.038, SE = 0.004, P < 0.001) and hair cortisol (B = −0.003, SE = 0.001, P = 0.029). However, in the fully‐adjusted models, both associations were attenuated and only the association with depressive symptoms remained statistically significant (B = −0.015, SE = 0.004, P < 0.001; hair cortisol B = −0.002, SE = 0.001, P = 0.088). Conclusion In a large sample of older adults in England, grip strength was negatively associated with depressive symptoms. Results were inconclusive regarding the association between grip strength and chronic stress. Further research examining the longitudinal relationships between muscular strength and specific aspects of mental health, while also exploring the neurobiological mechanisms underlying these associations, is warranted before recommendations for policy and practice can be made.

The Association of Grip Strength with Depressive Symptoms among Middle-Aged and Older Adults with Different Chronic Diseases

“…Moreover, decreased functional performance results in reduced ability to undertake one’s activities of daily living, which increases social isolation and the risk of depression [ 41 ]. The relationship between depressive symptoms and grip strength is likely bidirectional [ 20 ]. However, it seems that this relationship should be considered separately for those with different chronic conditions.…”

“…Potential confounders included gender, age, education level, living place, alcohol consumption, body mass index (BMI), and self-perceived health. Studies already have proven that there are significant differences in the association of grip strength and depressive symptoms between gender and age [ 20 , 23 ]. Educational level and living place are associated to both grip strength and depression [ 29 ].…”

“…Educational level and living place are associated to both grip strength and depression [ 29 ]. Alcohol consumption and BMI were previously used as confounder variables in similar analyses [ 20 , 22 , 23 ]. Self-reported health is an important variable when the sample is comprised of older adults, especially considering participants with chronic disease, as the subjective evaluation of health could be a proxy of the individual health status influencing both grip strength and mental health [ 30 ].…”

“…Several studies have reported that low grip strength is associated with depressive symptoms, in men and women, independent of age [ 18 , 19 , 20 , 21 , 22 , 23 ]. However, the association of grip strength and depressive symptoms in the presence of different chronic diseases has not been studied yet.…”

The Effect of Muscular Strength on Depression Symptoms in Adults: A Systematic Review and Meta-Analysis

“…For the five clinical trial studies, the instruments used to assess the muscular strength or the depression symptoms were different among the studies. From the 16 observational studies, the data from 9 were used for meta-analysis [11,[21][22][23][24][25][26][27][28]. The seven studies not included were eliminated based on the heterogeneity of the association measure between muscular strength and depression symptoms.…”