Author + information
- Dennis T. Ko, MD, MSc∗ ( and )
- Jack V. Tu, MD, PhD
- ↵∗Institute for Clinical Evaluative Sciences, 2075 Bayview Avenue, G 106, Toronto, Ontario M4N 3M5, Canada
We appreciate the comments raised by Dr. Salonen regarding the potential role of alcohol on our results. Dr. Salonen suggests that the relationship between high-density lipoprotein (HDL) cholesterol and outcomes may be discordant based on alcohol intake or liver enzyme levels (1).
In our study, we evaluated more than 630,000 individuals without prior cardiovascular conditions (2). We were able to impute alcohol use in the cohort using data from the Canadian Community Health Survey (CCHS), an ongoing Canada-wide population-based survey that collected information on self-reported health behavior. We found that 12.5% of individuals had heavy alcohol consumption (defined as ≥5 drinks on 12 occasions per year).
The evaluation of the independent association of HDL-cholesterol (HDL-C) level and cause-specific mortality was conducted by adjusting for liver disease (identified using administrative database codes), heavy alcohol consumption (imputed from the CCHS), demographics, and comorbidities. We found that individuals with lower HDL-C levels had increased hazard of cardiovascular deaths, cancer deaths, and noncardiovascular noncancer deaths. In addition, we also observed individuals who had very high HDL-C levels had increased hazard of noncardiovascular deaths. We agree that future research into reasons underlying higher noncardiovascular deaths among individuals with very high HDL-C levels is warranted and that alcohol intake could be an important contributor. In light of the inability of randomized trials to improve clinical outcomes by increasing HDL-C levels (3), and a Mendelian study showing no reduced clinical risk with genetic mechanism that raise HDL-C levels (4), our study adds to the existing literature suggesting that HDL-C level is unlikely to represent a specific cardiovascular risk factor (2).
Please note: Dr. Ko is supported by a Clinician Scientist Award from the Heart and Stroke Foundation (HSF), Ontario office. Dr. Tu is supported by a Canada Research Chair in Health Services Research and an Eaton Family Scholar award.
- 2017 American College of Cardiology Foundation
- Salonen J.T.
- Ko D.T.,
- Alter D.A.,
- Guo H.,
- et al.