Cardiovascular Events as a Function of Serum Bilirubin Levels in a Large Statin-Treated Cohort
Background—Serum bilirubin is an endogenous antioxidant that is routinely measured prior to statin prescription primarily to assess liver function, but the association with cardiovascular disease (CVD) in this population has not been explored.
Method and Results—We identified patients from a United Kingdom primary care database (The Health Improvement Network) with measurements of serum total bilirubin levels recorded three months prior to first statin treatment between January 1st 2000 and December 31st 2010 and with no history of liver disease or CVD. In total 130,052 patients met the inclusion criteria and after a median follow-up of 43 months, there were 7,850 CVD events. In men, the incidence of CVD in the lowest decile category of bilirubin (1-6 μmol/L [0.06-0.35 mg/dL]) was 215 per 10,000 person years (PYs) compared with 163 per 10,000 PYs in the highest decile (19-40 μmol/L [1.1-2.3 mg/dL]). Similar differences were seen for women. After accounting for conventional CVD risk factors, the associations with bilirubin were non-linear (L-shaped) and the models predicted that, compared to patients with a bilirubin level of 10 μmol/L (0.6 mg/dL), those with a similar CVD risk profile but a bilirubin level of 5 μmol/L (0.3 mg/dL) had a 18% (95%CI; 9-27%) higher risk of any CVD event, a 34% (95%CI; 13-56%) higher risk of myocardial infarction, and a 33% (95%CI; 21-46%) higher risk of death from any cause.
Conclusions—Serum bilirubin level measured prior to statin prescription in the UK to assess liver function is an independent risk factor for CVD and death in both men and women.
- Received April 23, 2012.
- Accepted September 24, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited