Tobacco Consumption and High-Sensitivity Cardiac Troponin I in the General Population: The HUNT Study.

Background Cardiac troponins represent a sensitive index of subclinical myocardial injury and are associated with increased risk of cardiovascular events in the general population. Despite positive associations with cardiovascular risk of both cardiac troponins and cigarette smoking, concentrations of cardiac troponin I measured by high-sensitivity assays (hs-cTnI) are paradoxically lower in current smokers than in never-smokers. The impact of smoking intensity and time from smoking cessation on hs-cTnI remains unknown. Methods and Results hs-cTnI concentrations were measured in 32028 subjects free from cardiovascular disease enrolled in the prospective, population-based HUNT (Trøndelag Health Study). Tobacco habits were self-reported and classified as never (n=14 559), former (n=14 248), and current (n=3221) smokers. Current smokers exhibited significantly lower concentrations of hs-cTnI than never-smokers (P<0.001). In adjusted models, both current smoking (-17.3%; 95% CI, -20.6 to -13.9%) and former smoking (-6.6%; 95% CI, -8.7 to -4.5%) were associated with significantly lower hs-cTnI concentrations. Among former smokers, higher smoking burden (>10 pack-years) were associated with lower concentrations of hs-cTnI. Time since smoking cessation was associated with increasing concentrations of hs-cTnI in a dose-dependent manner (P for trend<0.001), and subjects who quit smoking >30 years ago had concentrations of hs-cTnI comparable with those of never-smokers. Conclusions In the general population, both current and former cigarette smoking is associated with lower concentrations of hs-cTnI. In former smokers, there was a dose-response relationship between pack-years of smoking, and hs-cTnI. Time since smoking cessation was associated with increasing concentrations of hs-cTnI, indicating a continuum of hs-cTnI from current smoker to never-smokers.

High-Sensitivity Cardiac Troponin I and T Response Following Strenuous Activity is Attenuated by Smokeless Tobacco: NEEDED (North Sea Race Endurance Exercise Study) 2014.

Background Use of snus, a smokeless tobacco product, is increasing in Scandinavia. Strenuous physical activity is associated with an acute increase in high-sensitivity cardiac troponin (swhs-cTn) concentrations. Current smoking is associated with lower hs-cTn, but whether this also holds true for smokeless tobacco and whether tobacco affects the hs-cTn response to exercise remain unknown. Methods and Results We measured hs-cTnI and hs-cTnT concentrations in 914 recreational athletes before and 3 and 24 hours after a 91-km bicycle race. Self-reported snus tobacco habits were reported as noncurrent (n=796) and current (n=118). The association between snus use and change in log-transformed hs-cTnI and hs-cTnT concentrations (ie, the differences between concentrations at baseline and 3 hours and 24 hours ) were assessed by multivariable linear regression analysis. Concentrations of hs-cTn at baseline were lower in current than in noncurrent snus users (hs-cTnI median, 1.7 ng/L; Q1 to Q3: 1.6-2.3 versus 2.0 ng/L; Q1 to Q3: 1.6-3.2 [P=0.020]; and hs-cTnT: median, 2.9 ng/L, Q1 to Q3: 2.9-3.5 versus 2.9 ng/L, Q1 to Q3: 2.9-4.3 [P=0.021]). In fully adjusted multivariable models, use of snus was associated with lower change in hs-cTn concentrations from baseline to 3 hours (hs-cTnI: -29% [P=0.002], hs-cTnT: -18% [P=0.010]) and 24 hours (hscTnI: -30% [P=0.010], hs-cTnT -19%, [P=0.013]). Conclusions Resting hs-cTn concentrations are lower and the exercise-induced cardiac troponin response is attenuated in current users of smokeless tobacco compared with nonusers. Further insight into the pathophysiological processes underlying the attenuated cardiac troponin response to exercise in tobacco users is needed. Registration URL: https://www.clini​caltr​ials.gov; Unique identifier: NCT02166216.

Biomarkers of cardiovascular injury and stress are associated with increased frequency of ventricular ectopy: a population-based study.

BACKGROUND: Asymptomatic ventricular arrhythmias are common and associated with increased risk of cardiovascular mortality. Cardiac troponins, natriuretic peptides and C-reactive protein (CRP) are also predictive of adverse cardiovascular events in the general population, but limited information is available on the relationship between these biomarkers and ventricular ectopy in a community-based population. The objectives were to evaluate the associations between ventricular ectopic activity and N-terminal pro-B-type natriuretic peptide (NT-proBNP), high sensitivity-troponin I (hs-TnI) and hs-CRP in a community-based setting. METHODS: We performed a 24 h Holter-recording and blood sampling in 498 subjects. Premature ventricular complexes (PVC) were classified as frequent at >5/h and the presence of any bigeminy, trigeminy or non-sustained ventricular tachycardia were classified as complex ventricular ectopy. The associations between biomarkers and ventricular arrhythmias were investigated by univariate and multivariate logistic regression analyses. RESULTS: Frequent PVC's and complex ventricular ectopy were detected in 46 (9%) and 47 (9%) participants respectively, and were associated with significantly (p < 0.001) higher concentrations of NT-proBNP and hs-TnI. The association between NT-proBNP and both frequent PVC's (p = 0.020) and complex ventricular ectopy (p = 0.001) remained significant after adjusting for conventional risk markers in multivariate analyses. CONCLUSION: Increased level of NT-proBNP was independently associated with ventricular ectopy, whereas no independent association was observed between hs-TnI and hs-CRP levels and ventricular ectopy in this community-based sample.

Impact of Smoking on Circulating Cardiac Troponin I Concentrations and Cardiovascular Events in the General Population: The HUNT Study (Nord-Trøndelag Health Study).

BACKGROUND: Both tobacco smoking and circulating cardiac troponin I (cTnI) levels are associated with the risk of acute myocardial infarction, heart failure, and cardiovascular death. However, whether cTnI levels differ according to smoking status and whether smoking modifies the prognostic relationship between cTnI and outcomes remain unclear. METHODS: Using data from a large, population-based cohort, we assessed the association between smoking and cTnI and the impact of smoking on the associations between cTnI levels and the incidence of acute myocardial infarction, heart failure, and cardiovascular death. cTnI was measured with a high-sensitivity assay in 3824 never smokers, 2341 former smokers, and 2550 current smokers participating in the prospective observational HUNT Study (Nord-Trøndelag Health Study). All subjects were free from known prior cardiovascular disease and diabetes mellitus at baseline. RESULTS: The age of the participants ranged from 19 to 94 years; 55.5% were women. Current smokers exhibited significantly lower levels of cTnI (median, 2.9 ng/L; interquartile range, 2.0-4.1 ng/L) than never smokers (3.2 ng/L; interquartile range, 2.2-4.7 ng/L; P<0.001) and former smokers (3.4 ng/L; interquartile range, 2.3-5.0 ng/L; P<0.001). This association remained significant after adjustment for potential confounders (B=-0.098; 95% confidence interval, -0.129 to -0.068). We observed an association between increasing concentrations of cTnI and clinical end points in the total study cohort (adjusted hazard ratio per log unit increase in cTnI, 1.41; 95% confidence interval, 1.29-1.54). This association was attenuated for current smokers (hazard ratio, 1.17; 95% confidence interval, 0.98-1.40) and was significantly weaker than in never/former smokers (P for interaction=0.003). Prognostic accuracy, as assessed by C statistics, was significantly lower in current smokers than in never smokers (P<0.001). In addition, cTnI provided no incremental prognostic information to the Framingham Cardiovascular Disease risk score in current smokers (P=0.08). CONCLUSIONS: Current smoking is associated with lower concentrations of cTnI, suggesting that substances in tobacco smoke may affect cardiomyocyte injury. The association between cTnI levels and cardiovascular end points is stronger in never/former smokers than in current smokers, compatible with the theory that the detrimental cardiovascular impact of current smoking is mediated via mechanisms other than subclinical myocardial injury.