Smoking Attenuates the Beneficial Effect of Physical Activity on Intima-Media Thickness of Carotid Artery in Young and Middle-Aged Smokers

Abstract

Background : Though the favorable effect of physical activity and the hazardous effect of smoking on the progression of atherosclerosis have been well studied, the interactive effect of the two factors has seldom been investigated. Methods : A total of 1,090 subjects from among examinees of screening for brain diseases (an annual medical checkup of the brain) from April 2007 to March 2008 were studied to clarify the effect of physical activity on current, former and never smokers in relation to maximum carotid intima-media thickness (IMT). Univariate and multivariate analyses were performed to investigate the relationship between maximum IMT and independent variables such as age, gender, coexisting disease, physical activity, alcohol drinking, family history, symptoms, BMI, systolic blood pressure, diastolic blood pressure, blood sugar, total cholesterol, HDL cholesterol, triglyceride, Bathel index and time since smoking cessation. Results : Univariate analysis revealed that only never smokers exhibited a significant relationship between physical activity and maximum IMT. Multiple regression analyses performed for three age specific groups ( ≤ 49, 50 - 59, ≥ 60), demonstrated that physical activity was not a significant predictor of maximum IMT in current and former smokers 49 years old and younger, and current smokers 50 - 59 years old, though the other multivariate analyses showed no meaningful results, including for never smokers. Conclusions : The present study revealed that for young and middle-aged current smokers, the favorable effect of physical activity on the prevention of carotid atherosclerosis might be attenuated by detrimental effect of smoking. doi:10.4021/jnr74w