Living alone reduces the decline of calf circumference among Chinese older adults: A 4-year longitudinal study

Background: Calf circumference (CC) is regarded as a surrogate marker of skeletal muscle mass with high sensitivity and specificity for predicting sarcopenia. A cross-sectional study reported older adults living alone were at high risk of developing sarcopenia. Whether living alone affects the change of calf circumference is unknown and there is no evidence from longitudinal study. The purpose of this study was to investigate the relationship between living arrangements and the change of calf circumferences among older adults in China. Methods: The data were from the Chinese Longitudinal Healthy Longevity Survey. A total of 2,203 older adults (age ≥65 years, mean age: 80.61 ± 8.30 years, 50.0% female) who were interviewed in 2014 and then 2018 follow-up survey were finally included for analysis. Living arrangements and other information were collected in 2014. Calf circumferences were measured and recorded in the questionnaires of two waves and the differences were calculated. Logistic regression analyses were conducted to evaluate the association of living arrangements (living alone or not living alone) with the change of calf circumferences (decline or no decline). Results: There were 446 (20.2%) participants living alone and 1,757 (79.8%) participants not living alone. After about 4 years, calf circumferences of 866 (39.3%) older adults declined. Compared to not living alone, living alone was negatively associated with calf circumference decline, even after adjustment for covariates (OR: 0.702, 95% CI: 0.547–0.901, p = 0.005). This significant association was found in 65–79 years old (OR: 0.619, 95% CI: 0.407–0.942, p = 0.025), female (OR: 0.567, 95% CI: 0.408–0.790, p = 0.001) and city/town (OR: 0.461, 95% CI: 0.310–0.685, p < 0.001) subgroups but not in advanced age (≥80 years old), male and rural subgroups. Conclusion: This study revealed that living alone was associated with a decreased risk of calf circumference decline among older adults, and might be a protective factor for sarcopenia.