Thiago Ricardo dos Santos Tenório

Heart rate variability and its relationship with central and general obesity in obese normotensive adolescents

ABSTRACT Objective: To analyze the relationship between the heart rate variability parameters and the indicators of central and general obesity in obese normotensive adolescents. Methods: Seventy-four 13 to 18 year-old obese normotensive adolescents participated in this study. The indicators analyzed for central and general obesity were waist circumference and body mass index, respectively. Heart rate variability was obtained by heart rate monitoring. For this, the adolescents remained in a supine position for 7 minutes with controlled breathing. Parameters were obtained in time domain (standard deviation of all the RR intervals, root mean square of successive differences between the normal adjacent RR intervals and the percentage of adjacent intervals with more than 50ms) and frequency domain variables (low and high frequency bands and the sympathovagal balance). Results: After adjustments for gender, age, and cardiorespiratory fitness, a negative correlation between the waist circumference and the root mean square of successive differences between the normal adjacent RR intervals (ß=-1.51; standard error=0.56; p<0.05) and the percentage of adjacent intervals with more than 50 ms (ß=-0.96; standard error=0.34; p<0.05) were observed, while the body mass index showed no significant correlation with any heart rate variability parameter (p>0.05). Conclusion: Central obesity is a better discriminator than general obesity of autonomic cardiac dysfunction in obese normotensive adolescents

Effect of Aerobic Exercise on Hunger Feelings and Satiety Regulating Hormones in Obese Teenage Girls

Exercise is implicated in modifying subsequent energy intake (EI) through alterations in hunger and/or satiety hormones. Our aim was to examine the effects of aerobic exercise on hunger, satiety regulatory peptides, and EI in obese adolescents. Nine obese girls (age: 13-18 years old, BMI: 33.74 ± 4.04 kg/m2) participated in this randomized controlled crossover study. Each participant randomly underwent 2 experimental protocols: control (seated for 150 min) and exercise (exercised for 30 min on a treadmill performed at ventilatory threshold [VT] intensity and then remained seated for 120 min). Leptin, peptide YY(3-36) (PYY(3-36)), and subjective hunger were measured at baseline as well as 30 min and 150 min, followed by 24-hr EI measurement. Exercise session resulted in an acute increase in PYY(3-36) (p < .01) without changes in leptin and/or hunger scores. The control session increased hunger scores (p < .01) and decreased circulating leptin levels (p = .03). There was a strong effect size for carbohydrate intake (d = 2.14) and a modest effect size for protein intake (d = 0.61) after the exercise compared with the control session. Exercise performed at VT intensity in this study appears to provoke a state of transient anorexia in obese girls. These changes may be linked to an increase in circulating PYY3-36 and maintenance of leptin levels.

Relation between leukocyte count, adiposity, and cardiorespiratory fitness in pubertal adolescents

Objective To compare the total and differential leukocyte count in obese and normal-weight adolescents, and to verify their possible relations with cardiorespiratory fitness and adiposity indicators. Methods A cross-sectional study conducted with 139 adolescents (107 obese and 32 normal weight) aged between 13 and 18 years. Cardiorespiratory fitness was determined by direct gas analysis during an incremental treadmill test. Total leukocytes and subsets were estimated by flow cytometry. Body composition was assessed by dual-energy X-ray absorptiometry. The t-test for independent samples was used for comparison between groups. The relation between leukocytes, cardiorespiratory fitness and adiposity indicators was verified by Pearson’s correlation and multiple linear regression (adjusted for age and body mass index) tests. Results Obese adolescents had higher leukocyte (8.12±2.36u/L x 103; p=0.001), neutrophil (4.33±1.86u/L x 103; p=0.002), and monocyte (0.70±0.22u/L x 103; p=0.002) counts compared to the levels of normal weight subjects. After the necessary adjustments, cardiorespiratory fitness had a negative association with leukocytes, neutrophils, and monocytes in boys. Conclusion Obese adolescents had higher total and differential leucocyte count when compared to normal weight individuals. We also observed a weak positive association between adiposity and total leukocyte, monocyte, and neutrophil counts, and in boys, a negative association between cardiorespiratory fitness and total count of leukocytes, monocytes, and neutrophils.

Efeitos de diferentes intensidades de exercício sobre a concentração sérica de interleucinas

The aim of this study was to analyze the acute and short-term effects of high and low exercise intensities on IL-6 and IL-10. Fifteen young healthy physically active males (21.0 ± 1.9 yrs) were submitted to 2 experimental trials (cross-over) with a 7-dais wash-out: high exercise intensity (80% VO2peak) and low exercise intensity (40% VO2peak) session. Blood samples were collected before exercise (baseline), immediately after exercise (acute), and two hours after the end of the exercise session (2 h). IL-6 and IL-10 circulating levels were determinate by ELISA. The results demonstrated an acute increase in IL-6 levels after high intensity compared to low intensity exercise (p < 0.05), however, IL-10 presented an acute decrease in response to low intensity exercise (p < 0.05). No effects were observed after 2 h of recovery from the session. Thus we conclude that acute exercise sessions are able to modulate the circulating levels of the studies cytokines, and the magnitudes of these changes are dependent of the exercise intensity.

Obstetric complications and mother's age at delivery are predictors of eating disorder symptoms among Health Science college students.

ABSTRACT Objective To identify the association between perinatal/neonatal factors and symptoms of eating disorders among college students. Methods Four hundred and eight college students (283 women), aged 18 to 23 years old, enrolled in the first semester of a Bachelor of Health Science degree program were included in the sample. Eating disorder symptoms and body image dissatisfaction were assessed with the Eating Attitudes Test and Bulimic Investigatory Test of Edinburgh. Information regarding birth weight, breastfeeding, obstetric complications, mother’s age at delivery, type of delivery, and birth order were self-reported by the volunteers after consulting their parents. Association between perinatal and neonatal factors and symptoms of anorexia nervosa and bulimia nervosa were assessed by binary logistic regression adjusted for sex, age, and body mass index. Results The likelihood of presenting with symptoms of anorexia nervosa was 0.5 time lower for those students born from the oldest mothers (odds ratio – OR=0.37; 95% confidence interval – 95%CI: 0.17-0.83). Relative to bulimia nervosa, the risk was higher among students who reported obstetric complications (OR=2.62; 95%CI: 1.03-6.67). Conclusion We observed the association between perinatal and neonatal factors with symptoms of eating disorders in college students.