Depressed mood and body mass index as predictors of muscle strength decline in old men

OBJECTIVE: To study depressed mood as a predictor of strength decline withi n body weight categories over a 3-year follow-up period. DESIGN: A prospective cohort study over 3 years. SETTING: Honolulu, Hawaii. PARTICIPANTS: The subjects were 2275 men participating in the Honolulu Hear t Program with an average age of 77.1 years (range 71-92 years), who were n ot cognitively impaired at baseline (Exam 4), and who participated in maxim al hand grip strength measurements at baseline and 3 years later (Exam 5). MEASUREMENTS: Hand grip strength was measured using a dynamometer. Depressi ve symptoms were studied using an Ii-item version of Center for Epidemiolog ic Studies Depression Scale with 9 as a cutoff. Body weight categories were formed on the basis of body mass index (BMI) (BMI = weight/height(2); unde rweight: BMI < 20; normal weight: BMI 20-24.99, overweight: BMI greater tha n or equal to 25). MAIN RESULTS: At baseline, 9.4% of the participants were rated as having de pressed mood. The mean individual strength change over 3 years was -6.9% (s tandard deviation 14.0). Steep strength decline was determined as losing gr eater than or equal to 14% (lowest quartile). The proportions of those with steep strength decline in the groups based on combined distributions of BM I and depressed mood were: underweight/ depressed (n = 22) 41%, underweight /not depressed (n 200) 28%, normal weight/depressed (n = 127) 30%, normal w eight/not depressed (n = 1181) 25%, overweight/depressed (n = 55) 31%, over weight/not depressed (n = 675, referent) 21%. After adjusting for baseline strength, age, height, sociodemographic variables and diseases, the odds ra tio for steep strength decline was more than four rimes greater among those who were depressed and underweight, and twice as great among people who we re depressed and normal weighs compared with those who were nondepressed an d over-weight. The risks of nondepressed under- and normal weight people an d depressed overweight people did not differ from the reference group. CONCLUSIONS: Depressed mood was associated with increased risk of steep str ength decline, in particular in older men with low body weight. Low body we ight in combination with depressed mood may be an indicator of frailty or s evere disease status that leads to accelerated strength loss and disability .