a1 Department of Nursing, Ching Kuo Institute of Management and Health, Keelung, Taiwan
a2 Division of Mental Health and Addiction Medicine,Institute of Population Health Sciences, National Health Research Institutes, Zhunan, Miaoli County, Taiwan
a3 Institute of Public Health, National Yang-Ming University, Taipei, Taiwan
a4 Center for Population and Health Survey Research, Bureau of Health Promotion, Department of Health, Taichung, Taiwan
a5 Institute of Epidemiology, College of Public Health, National Taiwan University, Taipei, Taiwan
a6 Departments of Psychiatry, National Taiwan University Hospital, Taipei, 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.
(Received February 22 2010)
(Revised October 18 2010)
(Accepted November 23 2010)
(Online publication January 05 2011)
c1 Address for correspondence: W. J. Chen, M.D., Sc.D., Institute of Epidemiology, College of Public Health, National Taiwan University, 17 Xu-Zhou Road, Taipei 100, Taiwan. (Email: firstname.lastname@example.org)