Influence of skinfold sum and peak VO(2) on immune function in children.

OBJECTIVE: To measure the relationship of skinfold sum and peak VO 2 power with immune function in children. DESIGN: Cross-sectional, with all children tested twice during a 2 month period for peak VO 2 , sum of two skinfolds, and immune function, with data from the two measures averaged and then correlated (α level, < 0.01). Immune measures included leukocyte and lymphocyte subset counts, delayed-typed hypersensitivity (DTH), global IgG antibody response over 4 weeks to pneumococcal vaccination (plgG), salivary IgA concentration (slgA), PHA-stimulated lymphocyte proliferation (PHA-SLP), natural killer cell activity (NKCA), and granulocyte and monocyte phagocytosis and oxidative burst activity. SUBJECTS: Seventy-three children (n = 42 males, n = 31 females) ranging in age from 7 to 13 y (mean±s.d. age, 9.9±1.7y). The mean skinfold sum was 28.9±17.1 mm, and peak VO 2 45.8±8.1 ml/kg/min. RESULTS: Peak VO 2 , skinfold sum, and immune measures did not differ significantly by age or gender. Therefore, correlations were made on combined indices for all subjects. Peak VO 2 and the skinfold sum were not significantly correlated with NKCA, oxidative burst activity, plgG or DTH. Peak VO 2 was negatively correlated with monocyte phagocytosis (r= -0.30, P=0.012) and positively correlated with PHA-SLP (6.25 μg/ml; r=0.35, P=0.004). The skinfold sum was positively correlated with the total leukocyte count (r=0.39, P<0.001), granulocyte count (r=0.36, P=0.002), monocyte count (r=0.38, P=0.001), monocyte phagocytosis (r=0.41, P<0.001), granulocyte phagocytosis (r= 0.35, P=0.003), and slgA (r= 0.32, P=0.006), and negatively correlated with PHA-SLP (6.25 μg/ml; r=-0.39, P=0.001). CONCLUSIONS: Data from this study indicate that a high skinfold sum is related to elevated leukocyte subset counts and monocyte/granulocyte phagocytosis, and low PHA-SLP in children.