AUTHOR=Felício João Soares , de Alcântara Angélica Leite , Janaú Luísa Corrêa , de Moraes Lorena Vilhena , de Oliveira Maria Clara Neres Iunes , de Lemos Manuela Nascimento , de Souza Neto Norberto Jorge Kzan , Neto João Felício Abrahão , da Silva Wanderson Maia , de Souza Ícaro José Araújo , Said Nivin Mazen , de Lemos Gabriela Nascimento , Vieira Giovana Miranda , Khayat André Salim , Santos Ândrea Kely Campos Ribeiro dos , de Queiroz Natércia Neves Marques , de Sousa Ana Carolina Contente Braga , Santos Márcia Costa dos , de Melo Franciane Trindade Cunha , Piani Pedro Paulo Freire , Felício Karem Miléo TITLE=Association of Soy and Exclusive Breastfeeding With Central Precocious Puberty: A Case-Control Study JOURNAL=Frontiers in Endocrinology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2021.667029 DOI=10.3389/fendo.2021.667029 ISSN=1664-2392 ABSTRACT=Introduction

While soy is suggested as a possible risk factor, exclusive breastfeeding (EBF) has a likely protective effect in precocious puberty. Our aim was to evaluate the association between both of these variables with central precocious puberty (CPP)

Methods

We performed a retrospective, case-control study. A total of 161 girls were divided into two groups: 84 patients diagnosed with CPP composed the case group and 77 patients without the diagnosis of CPP (had gone through normal onset of puberty) were the control group.

Results

Our control group had a higher presence of EBF >6 months, which was an important protective factor for CPP (OR: 0.5; IC 95%: 0.3–0.9, p = 0.05) and also correlated negatively with the presence of it (r = −0.2; p < 0.05). Oppositely, the use of soy was significantly higher in the CPP group, (OR: 3.8; IC 95%: 1.5–6, p < 0.05) and positively correlating (r = 0.2; p < 0.01) with the presence of CPP. Duration of soy intake (years) correlated with bone age (r = 0.415; p < 0.05). A logistic regression was performed to evaluate the effects of EBF duration and soy on CPP. The model was significant (x² (2) = 20,715, p = <0.001) and explained 12.2% (Nagelkerke R2) of the variance, correctly classifying 62.5% of cases. EBF was associated with a reduction of likelihood of having CPP [OR = 0,187 (CI = 0.055–0,635); Wald = 7,222, p = 0.007], while soy intake increased the risk [OR = 3.505 (CI) = 1,688–7,279, Wald = 11,319, p = 0.001].

Conclusion

Our data found the use of soy was associated with CPP. Additionally, EBF was pointed as a protective factor. However, future prospective studies are needed to clarify this issue.