Normative Reference Values for Handgrip Strength in Chilean Children at 8-12 Years Old Using the Empirical Distribution and the Lambda, Mu, and Sigma Statistical Methods.

ABSTRACT: Garcia-Hermoso, A, Cofre-Bolados, C, Andrade-Schnettler, R, Ceballos-Ceballos, R, Fernández-Vergara, O, Vegas-Heredia, ED, Ramírez-Vélez, R, and Izquierdo, M. Normative reference values for handgrip strength in Chilean children at 8-12 years old using the empirical distribution and the lambda, mu, and sigma statistical methods. J Strength Cond Res 35(1): 260-266, 2021-The aim of this study was 2-fold (a) to provide sex- and age-specific handgrip reference standards for Chilean children aged 8-12 years and (b) to compare the levels of handgrip strength of Chilean children with those of children from other countries. This cross-sectional study enrolled 2,026 schoolchildren (boys n = 1,334 and girls n = 692, mean age 10.18 [1.16] years old). Handgrip strength was measured using a hand dynamometer with an adjustable grip. Relative handgrip strength was calculated by dividing handgrip strength by body mass (handgrip strength kg per mass kg). Smoothed centile curves and tables for the 10th, 20th, 30th, 40th, 50th, 60th, 70th, 80th, and 90th centiles were calculated using Cole's lambda, mu, and sigma method. The results indicate that mean handgrip strength was greater among boys than girls. Handgrip strength peaked at 16.25 (5.03) kg in boys and 14.90 (4.32) kg in girls. In addition, relative handgrip strength peaked at 0.38 (0.08) in boys and 0.34 (0.07) in girls. Chilean children of both sexes scored higher than their South American counterparts from Colombia and Peru but showed lower handgrip strength than European and Australian children. Our results provide, for the first time, sex- and age-specific handgrip reference standards for Chilean children aged 8-12.9 years. These normative reference values could help identify the levels of handgrip strength that need attention to provide appropriate feedback and advice to children about how to best improve their overall physical fitness.

Independent and combined effects of handgrip strength and adherence to a Mediterranean diet on blood pressure in Chilean children.

OBJECTIVE: The aim of the study was to examine the combined associations between handgrip strength (HGS) and adherence to a Mediterranean diet with blood pressure (BP) in Chilean children. METHODS: This cross-sectional study enrolled 1140 children (794 boys and 346 girls) 8 to 12 y of age. HGS was measured using a hand dynamometer with an adjustable grip. Adherence to a Mediterranean diet was assessed with the Kidmed score. Resting BP was measured by an automated monitor using an appropriately sized cuff. Elevated BP was defined as ≥90th percentile, and high HGS was defined as sex- and age-specific normative ≥80th percentile for the HGS. RESULTS: The prevalence of elevated systolic BP, diastolic BP, and overall BP were 16.6%, 12.9%, and 8.1%, respectively. HGS was negatively associated with BP parameters in an unadjusted and adjusted model after considering potential confounders (age, sex, body mass index z-score, and HGS). Regarding diet adherence, the unadjusted model reveals that children with high adherence to the Mediterranean diet showed lower BP levels (systolic, diastolic, and mean arterial pressure) compared with children with low-medium adherence; however, these differences disappear after considering potential confounders. The combination of high HGS and optimal adherence to a Mediterranean diet was negatively associated with BP. CONCLUSIONS: Children with a high HGS levels (i.e., ≥80th percentile) may somewhat overcome the deleterious effects of low adherence to a Mediterranean diet. Therefore, these findings suggest that the combination of these two components of a healthy lifestyle, especially HGS may be beneficial to children's BP.