Endocrine disruptors as risk factors for idiopathic premature thelarche in girls: A case-control study.

Introduction. Idiopathic premature thelarche (IPT) is defined as breast growth in girls before age 8 without activation of the gonadotrophic axis. Among the probable etiologies, endocrine disruptors (ED) with estrogenic action have been suggested. Objective. To evaluate whether there is an association between exposure and degree of exposure to the main EDs with estrogenic action in our environment and the development of IPT. Population and methods. Structured survey of caregivers of girls aged 3 to 8 years diagnosed with IPT and controls. The exposure evaluated included different EDs: bisphenol A (BPA), phytoestrogens, phthalates, and parabens, considering the degree of exposure according to weekly frequency. Results. Caregivers of 50 cases (7.2±1.3 years) and 48 controls (6.7±1.5 years) were interviewed. An association was found between IPT and exposure to phytoestrogens in food (OR: 14.6; 95%CI 1.8-118; p<0.01), the use of BPA containers exposed to temperature changes (OR 2.6; 95%CI 1.1-6.5; p<0.05), contact with phthalates (OR 2.9; 95%CI 1.2-7.5; p<0.05) and parabens (OR 2.7; 95%CI 1.2-6,1; p<0.05). In all the detailed EDs, we also found an association of IPT according to their degree of exposure. Conclusions. Exposure and degree of exposure to different sources of phytoestrogens, BPA, parabens, and phthalates were associated with the development of IPT.