CYP17Genotypes Differ in Salivary 17-β Estradiol Levels: A Study Based on Hormonal Profiles from Entire Menstrual Cycles

Abstract

Variation in the levels of sex-steroid hormones results from differences in developmental conditions, adult lifestyle, and genetic polymorphism. Genes involved in sex-steroid biosynthesis have been implicated to influence levels of hormones in premenopausal women, but the results were inconclusive. We tested variation among women in levels of salivary estradiol (E 2 ) corresponding to CYP17 genotypes. CYP17 encodes cytochrome P450c17A, which mediates two enzymes important in E 2 synthesis. In contrast to the earlier studies that relied on one or a few samples for assessing the E 2 levels of an individual woman, our study is based on daily collected saliva samples for one entire menstrual cycle. Sixty Polish women, ages 24 to 36 years, with regular menstrual cycles and no reported fertility problems participated in the study. Women with A2/A2 genotype had 54% higher mean E 2 levels than women with A1/A1 genotype (P = 0.0001) and 37% higher than women with A1/A2 genotype (P = 0.0008). Heterozygous A1/A2 women had 13 % higher E 2 levels than homozygous A1/A1 women (but this difference was significant only in a nonparametric test). Levels of E 2 during the day with highest E 2 (day À1) were 72% higher in A2/A2 compared with A1/A1 (P = 0.01) and 52 % higher compared with A1/A2 (P = 0.03). Our results suggest that CYP17 genotype may serve as a biomarker of endocrine function in women of reproductive age. (Cancer Epidemiol Biomarkers Prev 2006;15(11):2131 -5)

Ethnicity or environment: effects of migration on ovarian reserve among Bangladeshi women in the United Kingdom

“…Interpopulation variation in rates of reproductive aging and age at menopause could explain why agematched women from different ethnic groups vary in hormonal levels reflecting ovarian reserve, and why they respond differently to ART (8,20,36). Rather than offering primarily genetic explanations, reproductive ecologists have focused instead on aspects of the environment such as nutritional stress, excessive energy expenditure, or immunological challenges to explain the often significant differences in gonadal function across populations (37)(38)(39), although the role of genetics has not been overlooked (40).…”

Influence of birth weight and adult body composition on 17β-estradiol levels in young women

“…Furthermore, as saliva can be readily collected from 21.01.2009 3 individuals on many occasions, it is possible to compare steroid levels across entire menstrual cycles among different women, rather than relying on one or a few timed blood samples (20).…”

Variants in hormone biosynthesis genes and risk of endometrial cancer

“…In addition, there is no evidence of association of genotype with serum levels of androgens, the precursors of estrogens (Figure 1). Higher levels of estrogens in women with the C allele have been reported in saliva [27], urine [28], and follicular fluid [29]. The association of the variant with higher levels of estrogen found in some studies would lead to the hypothesis that it would increase risk of endometrial cancer, in contrast to the reductions in risk noted in this and some other studies.…”