Effects of levels of cigarette smoke exposure on symptom-limited spiroergometry

Previous investigations demonstrated reduced exposure to selected cigarette smoke constituents in adult smokers switching from conventional cigarettes (CC) to an electrically heated cigarette smoking system (EHCSS). This study investigated whether reduced exposure and no smoking (NS) would improve exercise performance. In a 3-period crossover study, 18 male adult smokers (age, 43.6+/-5.3 years) of CC were randomized to smoke CC (tar, 11 mg; nicotine, 0.8 mg; carbon monoxide, 11 mg), to use EHCSS (tar, 3 mg; nicotine, 0.2 mg; carbon monoxide, 0.4 mg [Federal Trade Commission method]), or to NS for 3 days before performing symptom-limited spiroergometry. NS and EHCSS vs CC resulted in less severe dyspnea (NS, 44.4% [P<.01 vs CC;] EHCSS, 50% [P=.03 vs CC;] CC, 88.9%), higher working capacity (NS, 2.92+/-0.4 W/kg [P=.06 vs CC;] ECHSS, 2.92+/-0.4 W/kg [P=.04 vs CC;] CC, 2.86+/-0.5 W/kg), higher peak oxygen uptake (NS, 2694+/-466 mL O(2)/min [P=.08 vs CC;] EHCSS, 2830+/-606 mL O(2)/min [P=.03 vs CC;] CC, 2682+/-492 mL O(2)/min), higher anaerobic threshold (NS, 1324+/-306 mL O(2)/min; EHCSS, 1396+/-312 mL O(2)/min [P=.03 vs CC;] CC, 1315+/-290 mL O(2)/min), and higher maximum rate-pressure product (NS, 30.1+/-2.7 x 10(3) mm Hg/min; EHCSS, 2.8 x 10(3) mm Hg/min [P<.01 vs CC;] CC, 30.7+/-29.2+/-3.6 x 10(3) mm Hg/min) indicating that reduced exposure from tobacco smoke and NS for 3 days may improve cardiovascular function as detected by symptom-limited spiroergometry.