Association of homocysteine and waist-to-height ratio with poor sleep quality in community-dwelling individuals at high risk of stroke: a cross-sectional study based on two community screening rounds in 2015 and 2025

Background Poor sleep quality has been associated with cerebrovascular disease and is increasingly recognised as a potentially modifiable factor relevant to cerebrovascular health. Nevertheless, the prevalence of sleep problems and their metabolic-related factors among community-dwelling individuals at high risk of stroke remains under-researched. Homocysteine (Hcy) and waist-to-height ratio (WHtR) are related to vascular health and central adiposity, respectively, but their associations with poor sleep quality in this population remain insufficiently understood. Based on two community-based cross-sectional screening datasets from 2015 to 2025, this study aims to describe the prevalence of poor sleep quality in this population and to specifically investigate the association between Hcy and WHtR and poor sleep quality. Methods This study enrolled community-dwelling individuals at high risk of stroke in 2015 ( n = 402) and 2025 ( n = 430). Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI), with a PSQI score > 5 defined as poor sleep quality. A pooled cohort ( n = 689) was constructed after excluding duplicate individuals from the two screening rounds, and trends in the associations of Hcy and WHtR with poor sleep quality were further examined. Results The prevalence of poor sleep quality was 52.7% in 2015 and 57.4% in 2025. In separate multivariable logistic regression analyses, Hcy and WHtR were consistently associated with poor sleep quality in both screening cohorts ( P < 0.05). In the pooled cohort, each 1 µmol/L increase in Hcy was associated with 15.3% higher odds of poor sleep quality (OR = 1.153, 95% CI: 1.102–1.207, P < 0.001), while each 0.1-unit increase in WHtR was associated with 151.6% higher odds (OR = 2.516, 95% CI: 1.800–3.518, P < 0.001). Significant positive trends were observed across Hcy tertiles ( P for trend = 0.002) and WHtR tertiles ( P for trend = 0.001). Conclusion Higher Hcy levels and WHtR were consistently associated with greater odds of poor sleep quality across the two screening cohorts, with significant positive trends observed in the pooled analysis.