Hyperinsulinemia may contribute to hyperandrogenism because it reduces the levels of SHBG and IGFBP-1. In this study we determined serum levels of SHBG and IGFBP-1 and their association with androgen and insulin in 44 selected girls with premature pubarche (PP) and 18 pre-pubertal controls (C) (7.3±1.3 x 6.8±1.6years). The body mass index (BMI) and bone age (BA) were determined, as well as the serum levels of SHBG, IGFBP-1, insulin (I), glucose (G), testosterone (T), DHEAS, androstenedione (A), 17-hydroxyprogesterone (17OHP) and cortisol (F). Fasting glucose to insulin ratio (G/I) was calculated as an index of insulin resistance (IR). BA was higher in PP than in C, but BMI was similar in both groups. Serum levels of DHEAS, T and A were higher in PP than in C, whereas SHBG and IGFBP-1 were lower. SHBG was correlated with BMI, SDHEA, T, F, I, G/I and IGFBP-1; and IGFBP-1 was correlated with BMI, I and G/I ratio. In the multiple regression model, SHBG and IGFBP-1 were correlated only with BMI and G/I ratio (r²=0.45; p<0.01 and r²=0.44; p<0.01, respectively). The present data demonstrate that body weight and insulin have a synergic role in the regulation of serum SHBG and IGFBP-1 levels, suggesting that both could be tenuous markers of IR in PP.
SHBG; IGFBP-1; Insulin resistance; Premature pubarche
