Depression trajectories and obesity among the elderly in Taiwan

Background The present study aimed to ( a ) characterize 10-year trajectory patterns of depressive symptoms and ( b ) investigate the association between depressive trajectory and subsequent obesity, metabolic function and cortisol level. Method In a prospective study of Taiwanese adults aged ⩾60 years ( n =3922) between 1989 and 1999, depression was assessed using a 10-item short-form of the Center for Epidemiologic Studies Depression Scale and information on body mass index (BMI) was collected by self-report. A subsample ( n =445) of the original cohort in 1989 was drawn to assess metabolic variables and cortisol levels in a 2000 follow-up. After trajectory analyses were performed, multinomial logistic regression analyses were used to estimate the association estimates. Results We identified four distinctive trajectories of depressive symptoms: class 1 (persistent low, 41.8%); class 2 (persistent mild, 46.8%); class 3 (late peak, 4.2%); and class 4 (high-chronic, 7.2%). The results from both complete cases and multiple imputation analyses indicated that the odds of obesity were lower in the class 2, 3 or 4 elderly, as compared with those in class 1, while the odds of underweight were higher. The classes of older adults with more and persistent depressive symptoms showed a trend toward having both a lower BMI ( p =0.01) and a higher cortisol level ( p =0.04) compared with those with low depressive symptoms. Conclusions Incremental increases in depressive symptoms over time were associated with reduced risk of obesity and higher cortisol levels.