Association between body mass index and mental health status among community-dwelling older adults

Abstract Background Maintaining a better physical and mental health status is an important issue for older adults in their later life. Although obesity has been suggested to reduce the risk of mood disorders in older adults, the findings are controversial. Thus, we aimed to investigate the association between body mass index (BMI) and mental health status among older adults in Taipei City and to elucidate risk factors contributing to mood disorders. Methods The elderly health examination database was obtained from the Department of Health, Taipei City government, from 2005 to 2016. A total of 80,121 older adults underwent at least two publicly funded health examinations, with 398,416 visits. We used the Brief Symptom Rating Scale (BSRS-5) questionnaire to estimated relative risks among potential risk factors with the generalized estimating equations (GEE) model to measure the mental health status of older adults. Mood disorders were defined as a score of ≥ 6 on BSRS-5. BMI, age, education level, gender, living alone, income status, number of chronic diseases, smoking, drinking, and exercise were included as covariates. Results Older adults who are overweight or obese have a lower risk for mood disorders (adjusted odds ratio [OR] = 0.82; 95% confidence interval [CI] = 0.79 - 0.85), while those underweight have a higher risk (OR = 1.31; 95% CI = 1.21 - 1.41). Other results show that being male (OR = 0.66; 95% CI = 0.63 - 0.69), higher education (OR = 0.72; 95% CI = 0.69 - 0.75), and have exercise habits (OR = 0.73; 95% CI = 0.70 - 0.76) were all positively correlated with better emotional status. However, low income (OR = 1.24, 95% CI = 1.14 - 1.35) and having more chronic diseases (OR = 1.99, 95% CI = 1.87 - 2.11) were all correlated with poor mental status among older adults. Conclusions Keeping an appropriate weight or even being overweight might be beneficial for older adults. In addition, encouraging older adults to maintain exercise habits can also help improve mood disorders. Key messages • Keeping an appropriate weight or even being overweight might be beneficial for older adults. • Encouraging the elderly to maintain exercise habits can also help improve mood disorders.