Muscle strength and body fat percentage in children and adolescents from the Maule region, Chile

Objective. To analyze the association between relative handgrip strength (RHGS) and fat mass (FM) after controlling for the potential effect of maturity status. Methodology. Both male and female children and adolescents aged ≥ 7.5 to ≤ 15.49 years were studied. RHGS was assessed using a hydraulic hand dynamometer. FM percentage was established using a dual-energy X-ray absorptiometry. Age and sex differences in RHGS levels between normal weight and obese participants were studied with an analysis of covariance. A covariate was years from peak height velocity (maturity status). The association between RHGS and FM levels was analyzed using a partial correlation and controlling for age at peak height velocity. Results. A total of 1685 students (731 girls and 954 boys) participated. Four age groups were established (7.5-9.4 years, 9.5-11.4 years, 11.5- 13.4 years, and 13.5-15.4 years). RHGS increased with age in both males and females. FM values were high in all age groups. No differences were observed in groups 3 and 4 among girls or in group 4 among boys. Participants classified as normal weight showed a significantly higher RHGS than their obese peers. A negative association was noted between RHGS and FM. Conclusion. RHGS was shown to be negatively associated with FM after controlling for the effect of maturity status.