Cardiorespiratory fitness: relationship with the immune system of adolescents

Abstract

This work to investigate the relationship between cardiorespiratory fitness with count of cells in the immune system (IS) in adolescents. The sample was composed by 102 boys (B) and 131 (G) girls (12 to 17 years-old). BMI was calculated and categorized (Cole et al.) and absolute and relative VO2max was obtained through the shuttle run test (Leger et al.) and categorized according to Rodrigues et al. Maturation stage was assessing (Tanner). The cells of IS by leukogram was obtained. It was hypothesized (H) that individuals with higher VO2max could present a higher ratio of chances in the counting of cells in the SI. Was used frequency distribution, Student t test, ANOVAs one-way and binary logistic regression (p< 0.05). The overweight was demonstrated that 27.8% (B) 13.2% (G). The values of VO2max were between 29 to 59 ml.kg-1.min-1 and 25 to 53 ml.kg-1.min-1 to B and G, respectively. The average of IS cells differ between B and G, and in greater range in the: Leukocytes (B = 5697.1 cel.ml and G = 6496.9 cel.ml; t= 3,959 p = 0,000), Segmented (B= 3288,1 cel.ml and G= 4023,8 cel.ml; t= 4,145; p= 0,000), and neutrophils (B = 3306,9 cel.ml and G = 4101.2 cel.ml; t= 4,431 , p= 0,000) in G, while Eosinophils (B = 286.1 cel.ml and G = 211.1 cel.ml; t= 2,644; p= 0,009) had a higher count for B. There were differences between the maturational stages only between puberty stage and pos puberty for Leukocytes and Segmented in G. The analyses of relative VO2max indicated the M with low cardiorespiratory fitness is 4,6; 2,76; 3,57 respectively have more chances of eosinophils, lymphocytes and monocytes below the 50th percentile, as well as to observe the absolute VO2max, the R with regular fitness is 9,0; 5,16; 9,65 respectively have more chances of leukocytes, monocytes and neutrophils below the 50th percentile. The M showed that the regular fitness has 3.0 times more chances to have leukocytes and neutrophils below the 50th percentile. It is concluded that the higher the VO2max, the better the counting of cells of the SI in adolescents.