Abstract 10218: Differences in Treadmill Exercise Stress Testing Parameters Among Electronic Cigarette Vapers, Combustible Cigarette Smokers, and Controls: The Clues Study

Abstract

Background: Use of electronic nicotine delivery devices is increasing but their effects on exercise function are not well-characterized. We hypothesized that treadmill stress test outcomes would differ between chronic electronic cigarette users (“vapers”), combustible cigarette users (“smokers”), and non-smoking/non-vaping controls. Methods: CLUES (HL1393301) was a cross-sectional study of 395 individuals: 164 exclusive vapers (exhaled carbon monoxide [CO] <5 ppm, positive urine NicCheck I), 117 exclusive smokers (CO >5 ppm, positive urine NicCheck I), and 114 non-vaping/non-smoking controls (CO <5 ppm, negative urine NicCheck I). Participants completed a symptom-limited Balke treadmill stress test protocol, a mean (SD) of 91.3 (16.2) minutes after vaping, smoking, or resting. Outcome measures were peak achieved metabolic equivalents (METs), rate-pressure product (RPP, peak heart rate [HR]*systolic blood pressure), HR reserve (peak HR/[220-age]), and 60-second HR recovery (HRR60). Group differences were compared by general linear models with omnibus p-values adjusted for age, race, and sex and with post-hoc t-tests using Bonferroni-corrected p-values. Results: Vapers were 27.4 (10.6) years old (39% female, 86% white) and had vaped for 4.1 (2.7) years (16.3 [30.0] vape-years). Smokers were 42.8 (13.8) years old (44% female, 56% white) and had smoked for 23.0 (13.0) years (28.7 [26.5] pack-years). Controls were 30.8 (11.9) years old (50% female, 69% white). Age, race, and sex-adjusted mean (95% CIs) outcome values by group are in the Figure. Vapers performed worse than controls on all 4 exercise parameters: peak METs (p<0.001), peak RPP (p=0.020), HR reserve (p<0.001), and HRR60 (p=0.025) with intermediate values compared to smokers. Conclusion: Vapers consistently performed worse than controls on 4 treadmill exercise parameters that predict adverse cardiovascular disease outcomes with intermediate values compared to smokers.