Diet and Exercise Training Restore Blood Pressure and Vasodilatory Responses During Physiological Maneuvers in Obese Children

Abstract

Background-The effects of diet and diet plus exercise training on muscle vasodilatation during physiological maneuvers in obese children are unknown. We tested the hypothesis that (1) blood pressure (BP) and forearm vascular conductance (FVC) responses during handgrip exercise and mental stress would be altered in obese children and (2) diet plus exercise training would restore BP and FVC responses during exercise and mental stress in obese children. Methods and Results-Thirty-nine obese children (aged 10Ϯ0.2 years) were randomly divided into 2 groups: diet plus exercise training (nϭ21; body mass index [BMI]ϭ28Ϯ0.5 kg/m 2 ) and diet (nϭ18; BMIϭ30Ϯ0.4 kg/m 2 ). Ten age-matched lean control children (BMIϭ17Ϯ0.5 kg/m 2 ) were also studied. Forearm blood flow was measured by venous occlusion plethysmography. BP was monitored noninvasively. Handgrip exercise was performed at 30% maximal voluntary contraction for 3 minutes. Stroop color word test was performed for 4 minutes. Baseline BP was significantly higher and FVC was significantly lower in obese children. During exercise and mental stress, BP responses were significantly higher and FVC responses were significantly lower in obese children. Diet and diet plus exercise training significantly reduced body weight. Diet and diet plus exercise training significantly decreased BP levels during exercise and mental stress. Diet plus exercise training, in contrast to diet alone, significantly increased FVC responses during exercise

Sympathetic Vascular Tone in Human Obesity

“…Furthermore, obese normotensive subjects were heavier in the present study (BMI=35±1kg/m 2 ; Table IV.1). Importantly, current results are partly in agreement with previous reports showing blunted vasodilatatory responses to mental stress in obese children [Ribeiro et al, 2005] and obese men [Hamer et al, 2007]. Notably, weight loss through diet and exercise normalized vascular responses to mental stress in obese children [Ribeiro et al, 2005].…”

“…This result contrasts with a previous report showing that weight loss through diet and exercise normalized vascular responses to mental stress in children and women with obesity [Ribeiro et al, 2005;Tonacio et al, 2006]. In the present study, children were not recruited and weight loss was achieved without changes in physical activity.…”

Vitamina C restaura pressão arterial e a resposta vasodilatadora no antebraço em crianças obesas

“…The relationship between obesity and increased blood pressure in obese children has been consistently published in the literature 10,16 . In our study, we confirmed that the blood pressure of obese children at rest is significantly higher when compared to normal-weight children.…”

“…During sympathoexcitatory maneuvers, such as isometric exercise, cold pressor test or mental stress, the vasodilator reflex that should increase muscle blood flow is attenuated in obesity 5,9 . Furthermore, these changes are already present in obese children and it has been shown that non-pharmacological therapy based on diet and exercise can restore the physiological responses of blood pressure and vasodilation during physiological maneuvers of mental stress and isometric exercise 10,11 .…”

Endothelial dysfunction and arterial abnormalities in childhood obesity

“…On the other hand, dietary therapy in this study was not associated with weight loss, which is associated with improvements in FMD in adults. However, Ribeiro et al 72 recently conducted a similar study in which the treatment resulted in significant weight loss. As in the study by Woo et al, 71 obese children were randomised to either diet alone or diet plus exercise training (consisting of three 60-min sessions per week for 4 months).…”