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

Effect of smoking cessation on cardiac troponin I concentrations

Chronic elevation of cardiac troponin I (cTnI) is associated with heart failure and cardiovascular death. Paradoxically, observational studies have indicated that current smokers have lower cTnI concentrations than non-smokers. We examined determinants of cTnI in smokers and the effect of smoking cessation on cTnI. Overweight or obese smokers received motivational support and varenicline to aid cessation and dietary advice to limit weight gain. Quitters were defined according to the Russell standard (≤5 cigarettes after the quit date) and validated with expired breath CO <10 ppm. Of the total 122 participants, 108 completed assessments at 12 weeks and 78 were classified as quitters versus 30 who continued smoking. cTnI was measured with a high-sensitivity assay with a limit of detection of 1.2 ng/L (Abbott Diagnostics), and concentrations (log-transformed) were compared between quitters and continuing smokers. cTnI concentrations were significantly higher in men than women and correlated with age, but not with number of cigarettes/day. Quitters had median baseline and 12-week levels of 1.4 ng/L (interquartile range [IQR] 1.2-2.5) and 1.4 ng/L (IQR 1.2-2.4), respectively, while nonquitters had baseline and 12-week levels of 1.5 ng/L (IQR 1.2-2.9) and 1.8 ng/L (IQR 1.3-3.4), respectively. The change in cTnI concentrations from baseline to 12 weeks did not differ between quitters and continuous smokers (p = .7). The results suggest that smoking cessation does not affect levels of cTnI, a marker of chronic subclinical myocardial injury, in contrast to prior observational data suggesting that tobacco smoking is associated with lower cTn concentrations.

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.