Acute running and coronary heart disease risk markers in male cigarette smokers and nonsmokers: a randomized crossover trial

Purpose: Cigarette smoking is an independent risk factor for coronary heart disease (CHD) and is associated with impaired postprandial metabolism. Acute exercise reduces postprandial lipemia and improves other CHD risk markers in non-smokers. Less is known about responses in cigarette smokers. Methods: Twelve male cigarette smokers (mean(SD) age 23(4) years, BMI 24.9(3.0) kg/m2 ) and 12 male non-smokers (24(4) years, 24.1(2.0) kg/m2 ) completed two, 2-day conditions (control, exercise) in a randomised, crossover design. On day 1, participants rested for 9- hours (08:00-17:00) in both conditions except a 60-minute treadmill run (65(7)% peak oxygen uptake, 2.87(0.54) MJ) was completed between 6.5-7.5 h (14:30-15:30) in the exercise condition. On day 2 of both conditions, participants rested and consumed two high fat meals over 8-hours (09:00-17:00) during which 13 venous blood samples and nine resting arterial blood pressure measurements were taken. Results: Smokers exhibited higher postprandial triacylglycerol and C-reactive protein than non-smokers (main effect group effect size (Cohen’s d)≥0.94, P≤0.034). Previous day running reduced postprandial triacylglycerol, insulin and systolic and diastolic blood pressure (main effect condition d≥0.28, P≤0.044), and elevated postprandial non-esterified fatty acid and C-reactive protein (main effect condition d≥0.41, P≤0.044). Group-by-condition interactions were not apparent for any outcome across the total postprandial period (0-8 h; all P≥0.089), but the exercise-induced reduction in postprandial triacylglycerol in the early postprandial period (0-4 h) was greater in non-smokers than smokers (-21% (d=0.43) vs -5% (d=0.16), respectively; group-by-condition interaction P=0.061). Conclusions: Acute moderate-intensity running reduced postprandial triacylglycerol, insulin and resting arterial blood pressure the day after exercise in male cigarette smokers and non- 4 smokers. These findings highlight the ability of acute exercise to augment the postprandial metabolic health of cigarette smokers and non-smokers