The association between circadian syndrome and possible sarcopenia in an aging population: A 4-year follow-up study

Recently, circadian syndrome (CircS) is proposed as a novel risk cluster based on sleep disorder, depression, dyslipidemia, hyperglycemia, hypertension and abdominal obesity. To investigate the association between CircS and possible sarcopenia, this study was performed.

Possible sarcopenia is defined according to Asian Working Group for Sarcopenia in 2019, which includes measures of muscle strength and physical performance. In the baseline survey, 7,905 participants aged ≥ 40 years from the China Health and Retirement Longitudinal Study were included. Multivariate logistic regression was used to evaluate the association between CircS and possible sarcopenia. Subgroup and interactive analyses were adopted to verify the findings in the overall population and identify potential interactive effects. The obese population was excluded and the missing values were interpolated using multivariate imputation by chained equations as sensitivity analyses. In addition, the participants were followed up for four years to explore the longitudinal association between CircS and incident possible sarcopenia.

As per one increase of CircS components, participants had a 1.11-fold (95% CI = 1.07-1.14, P < 0.001) risk of prevalent possible sarcopenia in the full model. The CircS group was associated with a 1.30-fold (95% CI = 1.17-1.44) risk of prevalent possible sarcopenia (P < 0.001). No significant interactive effects of covariates on the association between CircS and prevalent possible sarcopenia were detected (all P for interaction > 0.05). All the subgroup and sensitivity analyses supported the positive association between CircS and possible sarcopenia. In the longitudinal follow-up, the odd ratio was 1.06 (95% CI = 1.00-1.13, P < 0.05) as per one increase of CircS components in the full model. The CircS group was also found to have an elevated risk of incident possible sarcopenia (odd ratio = 1.24, 95% CI = 1.03-1.50, P < 0.05) after adjusting all the covariates.

CircS is a risk factor for possible sarcopenia, which may serve as a predictor of possible sarcopenia for early identification and intervention.