Associations between serum bile acid profile and mortality in patients with coronary artery disease: a cohort study.

Bile acids, metabolic products of cholesterol, play a crucial regulatory role in glucose, lipid metabolism and immune homeostasis. However, few studies focused on the relationship between circulating bile acid levels and coronary artery disease (CAD). This study aimed to explore the relationship between serum bile acid profiles and mortality risk in patients with CAD. We tested 15 serum bile acids by Ultra-HPLC-MS/MS among 1730 CAD patients from Guangdong Coronary Artery Disease Cohort study. Cox proportional hazards regression models were used to estimate the associations between bile acids levels and cardiovascular/all-cause mortality risks. During the median 9.2-year follow-up, 405 all-cause and 261 cardiovascular deaths occurred. Serum cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA) and hyodeoxycholic acid (HDCA) levels were significantly associated with lower risks of cardiovascular mortality, with HRs ranging from 0.40 to 0.55 (95% CIs ranging between 0.28 and 0.78) for Q4 versus Q1 and HRs ranging from 0.64 to 0.85 (95% CIs ranging between 0.54 and 0.93) for per SD increment. These bile acids were also inversely associated with risks of all-cause mortality, with HRs ranging from 0.57 to 0.67 (95% CIs ranging between 0.42 and 0.88) for Q4 versus Q1 and HRs ranging from 0.81 to 0.88 (95% CIs ranging between 0.70 and 0.94) for per SD increment. Significant interactions were observed for CA with BMI, CDCA with CAD type, DCA with history of diabetes, and HDCA with age, suggesting that these bile acid-mortality associations may be modified by specific clinical factors. Our findings suggest that higher serum levels of unconjugated bile acids, specifically CA, CDCA, DCA and HDCA levels, are significantly associated with lower cardiovascular and all-cause mortality risks in CAD patients.