[Analysis of insulin and cytokines during development using a multiplexed immunoassay: implications in pediatrics]

Multiplexed immunoassays allow the simultaneous determination of multiple parameters from minute biological samples. Our aim was to establish the normal values of cytokines and insulin during pubertal development, as well as their relationship with adrenal and gonadal steroids.

Serum insulin, adiponectin, resistin, leptin, tumoral necrosis factor-α, interleukin-1β, interleukin-6 and interleukin-8 concentrations were studied in 147 healthy children (Tanner I, 18 males and 18 females; Tanner II, 17 males and 13 females; Tanner III and IV, 21 males and 19 females and Tanner V, 18 males and 23 females). The relationship of these parameters with free and total testosterone, estradiol, sex-hormone binding globulin, 17-hydroxyprogesterone, dehydroepiandrosterone sulphate, 3α-androstanediol glucuronide and Δ4-androstenedione levels were also analyzed.

The concentrations of insulin, resistin and leptin increased during development, with higher levels found in females. Adiponectin levels did not change, although higher concentrations were also observed in females than in males. Interleukin-6 and 8 increased and interleukin-1β levels decreased throughout development, without any evidence of sexual dimorphism. There are good correlations between adiponectin and sex-hormone binding globulin, as well as between leptin and Δ4-androstenedione.

Changes in these parameters seem to be related with adrenal and gonadal function. Pubertal stage and sex must be taken into consideration when these data are used.