Rationale:
There is significant in vitro evidence demonstrating anti-atherogenic effect of circulating Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). Also, decreased circulating TRAIL levels have been reported in patients with acute myocardial infarction and in those undergoing coronary catheterization due to suspected coronary atherosclerosis. However, it remains unknown if TRAIL levels are associated with sub-clinical coronary atherosclerosis.
Methods:
The study included 460 current and former smokers enrolled in the Pittsburgh COPD SCCOR study. Serum TRAIL levels were measured by electrochemiluminescence immunoassay, according to the manufacture’s protocol (Meso Scale Discovery, Gaithersburg, Maryland). Coronary atherosclerosis was assessed by a validated visual coronary artery calcium scoring system using non-EKG gated chest CT scans (Weston score). Ordinal logistic regression models were used to identify significant associations between categories of CAC score (0, 1-3, 4-8, and 9-12) and TRAIL level, and to adjust for cardiovascular risk factors.
Results:
The mean age of the 460 participants was 65.7 ± 6.3 years, 52.2% were male, and the mean pack years of smoking was 55.0 ± 30.8 years. In univariate analyses, each standard deviation decrease in TRAIL levels was associated with 1.42-fold increase in the odds of having calcium scores in one higher category (p<0.001). This association persisted despite adjustment for age, gender, race, body mass index, hypertension, diabetes, hyperlipidemia, pack years of smoking, and current smoking status (adjusted OR for higher category of calcium score per SD decrease in TRAIL level 1.22, p=0.04).
Conclusions:
Our results expand on the in vitro and in vivo data linking decreased TRAIL levels with increased atherosclerosis by demonstrating a novel association between lower circulating TRAIL and increased subclinical coronary atherosclerosis.
Effect of tumor necrosis factor administration in vivo on lipoprotein lipase activity in various tissues of the rat.