Reduction of exercise capacity in children from summer to winter is associated with lower sporting activity: a serial study

Polymorphism of the PPARD Gene and Dynamic Balance Performance in Han Chinese Children

BACKGROUND

Athletic performances are complex traits with heritability of ~66%. Dynamic balance is one of the most important athletic performances, and there has been little studies for it in sports genomics. The candidate PPARD gene was reported to be able to affect muscle development for balance predisposition and influence the athletic performance including skiing triumph in the Caucasian population. This study aims to investigate whether the PPARD gene is a susceptibility gene for dynamic balance performance in Han Chinese children.

RESULTS

A total 2244 children were recruited and their balance beam performances were measured. Five polymorphisms in the PPARD gene were genotyped through the MassARRAY Sequenom platform. Rs2016520 exerted significant association with dynamic balance performance (minor allele C, P = 0.015, Pcorrected < 0.05) and was affirmed in a meta-analysis by combining previously reported Caucasian cohorts (OR = 1.57, 95% CI = [1.30, 1.91], P < 10 -5) . Another polymorphism, rs2267668, was also significantly associated with dynamic balance performance (minor allele G, P = 0.015, Pcorrected < 0.05). In the dichotomous study, 321 cases (61% boys and 39% girls) and 370 controls (49% boys and 51% girls) in our samples were selected as representatives, and the thresholds were the mean velocity (0.737 m/s) ± standard deviation (0.264 m/s), in which rs2016520-C and rs2267668-G still remained significant (CI =1.41 [1.11~1.79], P = 0.004, Pcorrected < 0.016; CI =1.45 [1.14~1.86], P = 0.002, Pcorrected < 0.016). In different genders, consistent OR direction was observed for each variant.

CONCLUSIONS

Our results suggested that the PPARD gene is associated with dynamic balance performance of human being, and further studies to reveal its etiology is strongly suggested.

Body Weight and Not Exercise Capacity Determines Central Systolic Blood Pressure, a Surrogate for Arterial Stiffness, in Children and Adolescents

Cardiopulmonary fitness benefits cardiovascular health. Various studies have shown a strong negative correlation between exercise capacity and arterial stiffness in adults. However, evidence for this connection in children and adolescents is scarce. About 320 healthy children and adolescents (252 male, 14.0±2.1 years) were evaluated with regard to their demographic, anthropometric and hemodynamic parameters, and their peak oxygen uptake. Peripheral and central systolic blood pressures were measured with patients in a supine position using an oscillometric device. Peak oxygen uptake was assessed by cardiopulmonary exercise testing. In multivariate regression, only peripheral systolic blood pressure (β=0.653, P<.001) and body weight (β=0.284, P<.001) emerged as independent determinants for central systolic blood pressure. Body weight therefore determines central systolic blood pressure in children and adolescents rather than measures of cardiorespiratory fitness. The prevention of overweight in childhood is necessary to reduce stiffening of the arteries and delay the onset of cardiovascular disease.