Is the beta estradiol receptor receiving enough attention for its metabolic importance in postmenopause?

The relationship between menopause and the development of metabolic diseases is well established. In postmenopause women, there is an expansion of visceral white adipose tissue (WATv), which highly contributes to the rise of circulating lipids. Meanwhile, muscle glucose uptake decreases and hepatic glucose production increases. Consequently, in the pancreas, lipotoxicity and glycotoxicity lead to deficient insulin production. These factors initiate an energy imbalance and enhance the probability of developing cardiovascular and metabolic diseases. Although the activation of estradiol receptors (ER) has been shown to be beneficial for the WAT stock pattern, leading to the insulin-sensitive phenotype, authors have described the risk of these receptors' activation, contributing to neoplasia development. The selective activation of beta-type ER (ERβ) seems to be a promising strategy in the treatment of energy imbalance, acting on several tissues of metabolic importance and allowing an intervention with less risk for the development of estrogen-dependent neoplasia. However, the literature on the risks and benefits of selective ERβ activation still needs to increase. In this review, several aspects related to ERβ were considered, such as its physiological role in tissues of energy importance, beneficial effects, and risks of its stimulation during menopause. PubMed, SciELO, Cochrane, and Medline/Bireme databases were used in this study.

A multigenic combination of estrogen related genes are associated with the duration of fertility period in the Spanish population

OBJECTIVE

The duration of the fertile period (FP) can be considered a complex parameter that depends on the interaction of multiple factors. In the present study, the role of interaction between genetic variants within estrogen synthesis and signaling pathways in the FP in Spanish women is studied.

MATERIAL AND METHODS

Nine single nucleotide polymorphisms (SNPs) located at different candidate genes related to the estrogen signaling pathway were analyzed in 1980 Spanish postmenopausal women.

RESULTS

Independently, none of the nine markers were significantly associated with age at menopause. In contrast, survival analysis techniques suggest several epistatic interactions including these markers in relation to age at menopause, especially between ESR2, NRIP1 and BMP15: women who showed the three markers ESR2 (AA), BMP15 (rs3897937) (TC) and NRIP1 (AA), the FP was shorter than the control group of women without any of these markers (32.36 ± 1.49 versus 34.94 ± 0.32 years; p = 0.026). The digenic BMP15 (rs3897937) (TC) and NRIP1 (AA) combination were also associated with a decreased duration of the FP (33.32 ± 0.96 years, p = 0.031).

CONCLUSIONS

The results suggest that interactions of estrogen-related alleles may contribute to variance in FP in Spanish women.

A chromosome 19 locus positively influences the number of retrieved oocytes during stimulated cycles in Brazilian women

PURPOSE

To evaluate if several genetic loci that are associated with variation in normal menopause age and early menopause can account for a poor response to controlled ovarian stimulation.

METHODS

A total of 71 patients age ≤35 years old who were undergoing intracytoplasmic sperm injection were genotyped for four genetic variants that are associated with normal variation in menopausal age and early menopause. The patients were divided into two groups based upon treatment response: a poor responder group (PR group, n = 21) and a normal responder group (NR group, n = 50). The genetic variants rs244715, rs9379896, rs4806660 and rs16991615 were analyzed.

RESULTS

There was no significant difference in the incidence of the genetic variants between the NR and PR group. The risk allele for the chromosome 19 variant (rs4806660) demonstrated a protective effect for a poor ovarian response. The presence of a risk allele was associated with an increased response to COS, which resulted in an elevated number of follicles (Coef: 2.54, P = 0.041) and retrieved oocytes (Coef: 1.41, P = 0.041).

CONCLUSIONS

The genetic variants rs244715, rs9379896, rs4806660 and rs16991615 are not risk factors for poor ovarian response in Brazilian women. In contrast, rs4806660 is associated with higher number of follicles and retrieved oocytes. rs4806660 may be associated with an increased response to gonadotrophin stimulation in this population.