Prevalence and Determinants of Poor Sleep Quality Among Patients with Established Coronary Heart Disease in Kazakhstan: A Multi-Center Cross-Sectional Study

Background: Poor sleep quality is an increasingly recognized, modifiable cardiovascular risk factor, yet data among patients with established coronary heart disease (CHD) in Central Asia are scarce. We estimated the prevalence of poor sleep quality and identified its correlates in a Kazakhstani CHD population. Methods: In this multi-center cross-sectional study, 398 patients 6–24 months after an index coronary event were assessed for sleep quality. Sleep quality was measured with the Pittsburgh Sleep Quality Index (PSQI; >5 = poor). Anxiety and depression, physical activity, cognition, and clinical and socio-demographic variables were recorded. Associations were examined using logistic regression with subgroup and interaction analyses. Results: Poor sleep quality was reported by 147 patients (36.9%). In the adjusted model, anxiety was the only independent factor associated with poor sleep (OR 1.88, 95% CI: 1.10 to 3.23). The subgroup analysis suggested anxiety (OR 3.94) and lower education (OR 2.58) as correlates in women, whereas retirement (OR 2.27) and low physical activity (OR 2.31) were linked to poor sleep in men. A significant sex–anxiety interaction demonstrated a weaker anxiety effect in men. Conclusions: More than one-third of CHD patients reported poor sleep quality, driven primarily by anxiety, with distinct sex- and age-specific determinants. Sleep and psychological screening should be integrated into secondary prevention, with personalized approaches.