Body mass index, waist circumference, waist-hip ratio and depressive symptoms in Chinese elderly: a population-based study.

BACKGROUND: Studies that investigated the relationship between obesity and depressive symptoms in the elderly have generated conflicting findings, partly because of the use of body mass index (BMI) alone to measure obesity in the elderly. The use of BMI fails to account for varying proportions of muscle, fat and bone, and few studies have used other measures of central obesity, such as waist-hip ratio (WHR) and waist circumference (WC).

OBJECTIVES: We examined whether individually BMI, WHR and WC were consistently associated with depressive symptoms in the elderly.

METHODS: Analysis of cross-sectional data of 2604 community dwelling Chinese elderly aged 55 and above, including socio-emotional characteristics, self-rated health and functional status, anthropometric measurements and Geriatric Depression Scale (15 items, GDS-15).

RESULTS: There was a negative trend in the prevalence of depressive symptoms (GDS > or =5) across increasing BMI categories: 16.9% in low BMI, 14.2% in normal weight, 12.1% in moderate to high BMI. The associations for moderate to high BMI (OR, 0.77; p = 0.04) relative to normal BMI, were statistically significant after controlling for confounding variables. However, no consistent trends in the prevalence of depressive symptoms and OR's were observed for increasing WHR and WC categories.

CONCLUSION: Our results suggest that waist-hip and circumference measures of central obesity did not support an inverse relationship of obesity and depressive symptoms. An inverse relationship of BMI with depressive symptoms may indicate greater physiologic and functional reserve from greater muscle mass that protects against depressive symptoms.