Traditional Chinese medicine body constitution and sleep quality.

Study Objectives: To investigate the relationships between Traditional Chinese Medicine (TCM) body constitution and sleep quality in a large population-based cohort. Methods: This cross-sectional study included 8517 participants from the WELL China cohort. We used the Wang Qi Nine Body Constitution Questionnaire (WQ-9BC) to assess TCM body constitution and the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. We used multivariable logistic regression analyses to estimate odds ratios (ORs) for the association between body constitution and poor sleep quality (PSQI score > 5), adjusting for demographics, lifestyle factors, and comorbidities. Results: Compared with a balanced body constitution (1898; 22%), individuals with an unbalanced constitution had a 2.6-fold risk (95% CI = 2.3% to 3.0%), and those with an unbalanced tendency had a 1.5-fold risk of poor sleep quality (95% CI = 1.3% to 1.8%). All eight unbalanced constitutions were associated with a higher risk of poor sleep quality, with Qi stagnation (OR 4.0 [95% CI = 3.0% to 5.5%]) and blood stasis (OR 3.8 [95% CI = 2.3% to 6.2%]) having the highest ORs. About 52% of participants had multiple unbalanced constitutions and/or tendencies. The OR for poor sleep quality increased with the composite number of Yang deficiency, Yin deficiency, Qi deficiency, heat dampness, blood stasis, and Qi stagnation constitutions and/or tendencies. Conclusions: All eight unbalanced constitutions are associated with poor sleep quality in a dose-dependent manner, with Qi stagnation and blood stasis displaying the strongest associations. Multiple unbalanced constitutions and/or tendencies are cumulatively associated with poor sleep quality. Identifying TCM body constitution could help in detecting high-risk groups and designing targeted interventions.