Interaction between Body Mass Index and Depressive Symptoms in Older Adults: Evidence from a Large-Scale Population-Based Cohort Study

There are mixed results on the correlation between body mass index and depressive symptoms among older adults. This observational research was carried-out as part of a prospective cohort study on older adults (aged 60 years and over) living in an urban region, north of Iran. Age, gender, marital status, the number of comorbid disorders, self-satisfaction with the household's monthly income, and physical activity were assessed. The presence of depressive symptoms was examined and recorded by trained personnel using Geriatric Depression Scale (GDS). A total of 1000 older adults, including 544 (54.4%) men with a mean age of 69.82 +/- 7.35 years were included. Findings showed that 747 (74.7%) of the participants had overweight or obesity; and 635 people (63.5%) had no depressive symptoms. A significant positive correlation was observed between GDS score and body mass index (BMI); although, the correlation was not strong (r = 0.077; p = 0.01). The correlation between GDS score and BMI was not statistically significant with two genders (r = -0.041, p = 0.38 for women, and r = 0.038, p = 0.37 for men). The multivariable linear regression model revealed the significant effect of gender (B = 0.56; p = 0.02) and the number of comorbidities (B = 0.49: p < 0.001) on GDS score. This large-scale population-based study demonstrated the positive correlation of BMI and depressive symptoms in old age. The effect of gender and comorbidities seems to be more significant on depression than that of BMI.