Associations between muscular strength and mental health in cognitively normal older adults: a cross-sectional study from the AGUEDA trial.

OBJECTIVE: To examine the associations between muscular strength and mental health.

DESIGN: We used baseline data of 91 cognitively healthy older adults (71.69 ± 3.91 years old, 57 % women) participating in the AGUEDA randomized controlled trial.

METHODS: Muscular strength was assessed using both objective (i.e., handgrip strength, biceps curl, squats, and isokinetic test) and perceived (i.e., International Fitness Scale) indicators. Psychological ill-being indicators: anxiety, depression, stress, and loneliness; and psychological well-being indicators: satisfaction with life, self-esteem, and emotional well-being) were assessed using a set of valid and reliable self-reported questionnaires. Linear regression analyses were performed adjusting for sex, age, years of education, body mass index , alcohol, diet, and smoking (model 1), and additionally by cardiorespiratory fitness (model 2).

RESULTS: Elbow extension was positively associated with stress in model 1 ( β = 0.252, 95 % Confidence Interval [95 % CI] = 0.007 to 0.497, p = 0.044), and even after further adjustment for cardiorespiratory fitness ( β = 0.282, 95 % CI = 0.032 to 0.532, p = 0.028). Perceived strength was negatively associated with depressive symptoms in model 1 ( β = -0.271, 95 % CI = -0.491 to -0.049, p = 0.017) and model 2 reported associations tending towards significant ( β = -0.220, 95 % CI = -0.445 to 0.005, p = 0.055). Handgrip strength was positively associated with self-esteem in model 1 ( β = 0.558, 95 % CI = 0.168 to 0.949, p = 0.006) and model 2 ( β = 0.546, 95 % CI = 0.135 to 0.956, p = 0.010). No further associations were found among other muscular strength and mental health variables.

CONCLUSION: Handgrip had a moderate association with self-esteem and there was a small association between perceived strength with depressive symptoms and elbow extension with stress. No other associations were observed between muscular strength and mental health outcomes in cognitively normal older adults.