Influence of Cardiorespiratory Fitness onPPARGmRNA Expression Using Monozygotic Twin Case Control

Abstract

The influence of cardiorespiratory fitness (VO2max) on anthropometric variables andPPARGmRNA expression was investigated. Monozygotic twin pairs aged 11–18 years were grouped into discordant (D) and concordant (C) high and low VO2max groups. VO2max was determined by progressive maximal exercise test on treadmill with gas exchange analysis. Body mass (BM), BMI, waist circumference (WC), triceps (TR), and subscapular (SB) skinfold thicknesses were measured. Twins from the discordant group had differences in VO2max values (D-high =45.9±10.0versus D-low =32.4±10.6 mL·kg−1·min−1,P=0.025), while no differences were found in the concordant group (C-high =42.4±9.2versus C-low =38.8±9.8 mL·kg−1·min−1,P=0.952). In discordant group, VO2max was negatively correlated with TR + SB (r=-0.540,P=0.021) and positively correlated withPPARGexpression in leukocytes (r=0.952,P=0.001). Moreover,PPARGexpression was directly correlated with BM (r=0.714,P=0.047) and height (r=0.762,P=0.028). In concordant twins, VO2max was inversely correlated with BM (r=-0.290,P=0.027), BMI (r=-0.472,P=0.001), WC (r=-0.426,P=0.001), and TR + SB (r=-0.739,P=0.001). Twins D-high had 1.78-fold greaterPPARGexpression when compared with twins D-low (P=0.048). In conclusion, the cardiorespiratory fitness may modulatePPARGexpression in childhood and adolescence, independently of the genetic background.