Quantile Regression of Depression and Body Mass Index in Patients with Cor-onary Artery Disease in China / 中国卫生统计

ABSTRACT

Objective Depression and obesity are two major disorders associated with coronary heart disease ( CHD) , and both have a high prevalence. Different studies concluded different outcomes about the relation between body mass index ( BMI) and depression. The aim of this study was to assess the status of depression and investigate the relationship between de-pression and BMI in CHD patients using quantile regression. Methods 580 patients were enrolled. Depression was tested using the Zung Self-Rating Depression Scale ( SDS) . Demographic data and clinical data were recorded. Quantile regression was con-ducted to determine whether BMI was a predictor of depression. Results SDS scores were significant different in underweight, normal weight,overweight and obesity group (P<0. 001). Overweight and obesity patients were least depressed. Differences in SDS scores increased steeply as depression increased at 5th,10th,25th,50th,75th,90th and 95th percentiles,with the coefficients ranging from -0. 36 to -0. 88 in total population,-0. 26 to -1. 09 in male and -0. 46 to -0. 75 in female respectively. The effects of BMI on depression were significantly different in different quantiles of depression in total population ( P=0. 04 ) and in male (P=0. 006),but no difference in female. Conclusion There was also a phenomenon of "obesity paradox" between BMI and depression in CHD patients. The effects of BMI on depression were significantly different in different quantiles in total population and in male.