Background. Premature thelarche in later childhood may progress to central precocious puberty (CPP), which does not spontaneously resolve. Thelarche variant (TV) is a slowly progressive variant of precocious puberty. Aim: To determine and compare levels of insulin-like growth factor-I (IGF-I), IGF binding protein-3 (IGFBP-3) and anthropomorphic measures in girls with TV and CPP. Subjects: Prepubertal controls and girls with TV and CPP. Methods: Chronological and bone age, weight, height, BMI, height velocity (HV), and serum IGF-I, IGFBP-3, leptin, follicle-stimulating hormone (FSH) and lutenizing hormone (LH) levels were assessed. Results: Serum IGF-I levels, HV and IGF-I/IGFBP-3 ratio were significantly higher in girls with CPP compared to both controls and girls with TV. IGFBP-3 values for bone age (IGFBP-3(BA)) were significantly higher in the TV group compared to both controls and girls with CPP. FSH and LH concentrations were significantly higher in the CPP group compared to TV. Conclusion: HV, IGF-I, LH and FSH levels and IGF-I/IGFBP-3 ratio are elevated in girls with CPP compared to those with TV.
