Association among calf circumference, physical performance, and depression in the elderly Chinese population: a cross-sectional study

Background Depression and sarcopenia are common diseases in the elderly population. However, the association between them is controversial. Based on the Chinese Longitudinal Healthy Longevity Survey (CLHLS) database, a cross-sectional study was conducted to explore the relationship of calf circumference and physical performance with depression. Methods From the 8th wave of CLHLS conducted in 2018, data on calf circumference, physical performance, depressive symptoms, and demographic, socioeconomic, and health-related characteristics were collected. Multiple logistic regression was conducted to explore the impact of calf circumference, physical performance and their combination on depressive symptoms. Results We enrolled a total of 12,227 participants aged 83.4 +/- 11.0 years, including 5689 (46.5%) men and 6538 (53.5%) women. Patients with depression were more likely to have low calf circumference (2274 [68.2%] vs. 5406 [60.8%], p<0.001) and poor physical performance (3[0, 6] vs. 1[0, 4], p<0.001). A significant multiplicative interaction was found between calf circumference and physical performance in their effect on depression. After adjusting for confounding factors, multiple logistic regression showed that a significant inverse correlation persisted between physical performance and depressive symptoms in normal (odds ratio [OR] = 1.20, 95% confidence interval [CI]: 1.15-1.26, p<0.001) and low (OR = 1.14, 95% CI: 1.11-1.18, p<0.001) calf circumference group, while the association between calf circumference and depression disappeared. Participants with low calf circumference and poor physical performance were 2.21 times more likely to have depression than those with normal calf circumference and physical performance. All results were found to be robust in sensitivity analyses. Conclusions Physical performance was significantly associated with depression in the elderly Chinese population. Attention should be paid to assess depressive symptoms in patients with poor physical performance.