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Increased arterial stiffness is a strong predictor of future cardiovascular events and mortality. Flexibility is associated with arterial stiffness in healthy populations, but it is unclear if this is also the case in patients with stroke. We investigate the relationship between flexibility and arterial stiffness in patients with stroke. Ninety four patients with stroke (male n=68, female n=26, 61±9 years) were recruited in the present study. We measured a modified sit and reach test on chair as an index of flexibility. Arterial stiffness was assessed by carotid-femoral pulse wave velocity using applanation tonometry. There was a significant inversely association between flexibility and pulse wave velocity (r=-.48, p<.001). In multivariable linear regression models that adjusted for age, gender, body mass index, duration of stroke, systolic blood pressure, heart rate, medication, and cardiorespiratory fitness, flexibility was an independent associated with pulse wave velocity ( =-.19, p<.05). Patients with high flexibility had significantly lower pulse wave β velocity than patients with low flexibility (8.9 m/s vs. 11.8 m/s, p<.001). These findings demonstrate that high flexibility was associated with low arterial stiffness independent of risk factors and cardiorespiratory fitness in patients with stroke.

It is well known that autonomic nervous system activity is related with increasing risk of cardiovascular disease. The purpose of this study was to assess the effects of obesity and exercise on autonomic nervous system activity in obese adolescents. Twenty obese adolescents(13±0.5 year, 30.09±2.75 ㎏/㎡) were compared with 10 heathy normal weight subjects(13±0.5 year, 20.16±2.87 ㎏/㎡), twenty obese adolescents were randomly assigned to an exercise group(n=10) and control group(n=10). Exercise group participated in a 12 weeks school-based exercise program(60-90 min/day, 3 days/week). Autonomic nervous system activity were measured using heart rate variability(HRV) and heart rate recovery, Heart rate recovery was defined as the difference between heart rate at peak exercise test and 1, 2 minute later. Frequency domain(HFnu：High frequency normalized units, LFnu：Low frequency normalized units, LF/HF ratio and time domain(RMSSD：Root Mean Square of the Difference of Successive R to R Intervals, NN50：Number of successive NN intervals which differ by more than 50 ms, pNN50：Percentage of consecutive R to R Intervals differing by more than 50 ms) of HRV were calculated. Obese group showed a significant decrease HFnu and increase LFnu, LF/HF ratio which of the HRV compared to normal weight group. pNN50 was significant decrease in obese group. There were significant decrease in body weight (p=0.001), % body fat (p=0.004), waist circumference (p=0.001) and increase in cardiorespiratory fitness (p=0.001) after 12 weeks exercise program. NN50, pNN50, RMSSD, HFnu which component of parasympathetic nervous system activity increased in exercise group, but changes of between group were not statistically significant. These data indicate that obese adolescents had decreased parasympathetic nervous system activity and 12 weeks exercise program dose not affect autonomic nervous system activity improvements in obese adolescents.

Yoon, E.S., Jung, S.J., Jae, S.Y. Effects of exercise training program on carotid intima-media thickness and brachial artery endothelium-dependent flow mediated vasodilation in obese adolescents. The purpose of this study was to assess the effect of exercise training program on vascular structure and function in obese adolescents. Twenty obese adolescents (age 13-14 years, male, body mass index 30±3kg/m 2 ) were randomly assigned to an exercise training group (n=10) and a non-exercise control group (n=10). The subjects in the exercise training group performed supervised aerobic exercise programs with moderate intensity for 12 weeks, 60-90 minutes per session, 3 times per week. Brachial artery flow mediated vasodilatation and common carotid artery intima-media thickness(CIMT) were measured using B-mode ultrasound. There were significant decrease in body weight (p=0.001), % body fat (p=0.004), waist circumference (p=0.001) and increase in cardiorespiratory fitness (p=0.001) after 12 weeks exercise program. Maximal CIMT(p=0.043), but not mean CIMT(p=0.220), and brachial artery flow-mediated vasodilation (p=0.001) were significantly improved in the exercise group compared with the control group, while lipid profile and insulin resistance were not significantly improved in the exercise group. These data indicate that 12 weeks exercise training program reduced body weight, improved cardiorespiratory fitness and vascular structure/function in obese adolescents.