Many risk factors, including smoking, increase and accelerate atherosclerosis even in young ages. Although it has been shown that increased aortic stiffness and decreased aortic strain (AS) in smoker individuals, and improved aortic elastic properties with exercise training (ET), there is no satisfied evidence revealing how the regular ET influences this harmful effect of smoking. We aimed to evaluate this effect in young adults in this study.
75 smoker (age 20,64±1,06) (12,4±4,35 cig/d; mean 2,6±1,26 years) and 36 non-smoker (never smoke) (age 20,83±1,35) individuals who stated that hadnt done regular exercise previously were enrolled to study. Individuals who were not able to perform exercise or changed smoking habit were excluded. Body mass indexes (BMI), systolic and diastolic blood pressures (BP) were recorded. Aortic systolic (ASD) and diastolic diameters (ADD) were measured from the same view on the M-mode tracing at a level of 3 cm above the aortic valve on echocardiographic examination. Hence AS, aortic distensibility (AD) and Î² stiffness index (Î²SI) were calculated. The formulas to calculate these parameters are; AS(%)=(ASD-ADD)/ADDx100; AD(cm2/dyn/106)=(2xAS)/(SBP-DBP); and Î²SI=ln(SBP/DBP)/AS. Then all of the individuals were underwent exercise protocol, including chin-up (5-9 a day ), push-up (25-40 a day), sit-up (30-50 a day), physical-fitness exercises and at least 3 km running 3-5 times a week during the average of 5,3 months. After exercise period, the parameters mentioned above measured again and aortic strain and distensibility recalculated. Statistical analysis was performed by student t-test or Mann Whitney-U test using SPSS 11.0 for Windows.
Before ET, there were no any significant difference in age, BMI, BP and pulse pressure, interventricular septum thickness and LV ejection fractions between two groups. However AS and AD in smokers were significantly lower and Î²SI was higher than those of controls. AS, AD and Î²SI of both groups improved with the ET. However, the improvement of AS and AD were statistically significant in smoker subjects (14,96%, p=0,036; and 17,99%, p=0,024 respectively), while were not significant in non-smoker group (1,16%, p>0,05; and 1,86%, p>0,05). The decrease of Î²SI was also similar (smokers 14,91%, p=0,021; and nonsmokers 2,42%, p>0,05).
This study revealed that smoking affects aortic strain and distensibility, indicators of atherosclerotic process, adversely even in young ages similar to shown in previously. However regular exercise can help to recovery of aortic elastic properties.
Exercise Training, Smoking, Aortic Strain and Distensibility