The association between anthropometric factors and anti-Müllerian hormone levels in premenopausal women.

Adiposity has been associated with several health conditions as well as timing of menopause. Prior epidemiologic studies on the association of adiposity and anti-Müllerian hormone (AMH) have been inconsistent. We evaluated the relations of anthropometric measures with AMH at two time periods in a subset of premenopausal participants in the Nurses' Health Study II. This prospective study included 795 women who provided a premenopausal sample in 1996-1999 and in 2010-2012. Current weight and height, and weight at age 18 were assessed in 1989 and weight again in 1996-1999. Waist and hip circumference were measured and reported in 1993. In linear regression models adjusted for smoking, reproductive events, and other factors, AMH was inversely related to BMI at age 18 (P = .03) and in 1996-1999 (P < .0001). Higher waist circumference was related to lower AMH levels in 1996-1999 (p = .0009). BMI in 1996-1999 was inversely associated with AMH levels in 2010-2012 (P = .005). Weight gain between age 18 and 1996-1999 was strongly inversely associated with AMH levels in 1996-1999 (P < .0001) and in 2010-2012 (P < .0001). Our results indicate that adiposity and weight gain are associated with lower AMH levels, suggesting an adverse impact on ovarian function.

Anti-Müllerian hormone levels and breast cancer risk in the study of women's health across the nation.

PURPOSE: The relation of premenopausal anti-Müllerian hormone (AMH) levels with breast cancer risk has been evaluated in a few studies, but primarily in non-Hispanic White women. METHODS: We evaluated the association of AMH levels with breast cancer risk in Study of Women's Health Across the Nation (SWAN), a multi-ethnic cohort of women. At enrollment, participants had an intact uterus and ≥ 1 ovary, and ≥ 1 menstrual period in the last 3 months. AMH at first measurement was assessed in 1,529 pre- or perimenopausal women using a high-sensitivity ELISA assay; values were natural log transformed. Breast cancer diagnoses were assessed at enrollment and subsequent follow-up visits through 2018 (median 6.1 years). RESULTS: In total, 84 women reported an incident breast cancer diagnosis. In multivariable Cox regression models adjusting for age, race and ethnicity, body mass index, and other factors, higher AMH levels were associated with a non-significant increased breast cancer risk. Compared to women in the 1st quartile, the hazard ratio (95% confidence interval) for women in the 4th quartile was 1.77 (0.87-3.60). CONCLUSION: Our results did not suggest a significant association between AMH and breast cancer risk; however, estimates were consistent with prior studies that reported positive associations.

The association of parity and breastfeeding with anti-Müllerian hormone levels at two time points.

OBJECTIVE: To evaluate the association between parity and breastfeeding and anti-Müllerian hormone levels (AMH) and change in AMH levels over time. Furthermore, we examined whether AMH levels mediate the relation of parity and breastfeeding with age at menopause. STUDY DESIGN: Observational, prospective cohort study. MAIN OUTCOME MEASURES: AMH levels were assessed in a subset of premenopausal participants in the Nurses' Health Study II, including 1619 women who provided a blood sample in 1996-1999 and an additional 800 women who provided a second premenopausal sample in 2010-2012. RESULTS: In multivariable linear regression models adjusted for parity, body mass index, smoking, and other factors, mean log AMH levels in 1996-1999 were 39% higher in women reporting ≥25 months of total breastfeeding vs. <1 month (P for trend = 0.009). Parity was not associated with AMH levels after adjustment for breastfeeding. Neither parity nor breastfeeding was associated with decline in AMH levels over 11 to 15 years. Breastfeeding duration was positively associated with age at menopause (P for trend = 0.01), with evidence that the association was mediated via AMH. CONCLUSIONS: Our results suggest that breastfeeding is associated with higher AMH levels and later onset of menopause, and support the hypothesis that observed relations of parity with AMH levels and menopause timing may be largely attributable to breastfeeding.

Urinary Phthalate Biomarkers and Bone Mineral Density in Postmenopausal Women.

CONTEXT: Phthalates are endocrine-disrupting chemicals that could disrupt normal physiologic function, triggering detrimental impacts on bone. OBJECTIVE: We evaluated associations between urinary phthalate biomarkers and BMD in postmenopausal women participating in the prospective Women's Health Initiative (WHI). METHODS: We included WHI participants enrolled in the BMD substudy and selected for a nested case-control study of phthalates and breast cancer (N = 1255). We measured 13 phthalate biomarkers and creatinine in 2 to 3 urine samples per participant collected over 3 years, when all participants were cancer free. Total hip and femoral neck BMD were measured at baseline and year 3, concurrent with urine collection, via dual-energy x-ray absorptiometry. We fit multivariable generalized estimating equation models and linear mixed-effects models to estimate cross-sectional and longitudinal associations, respectively, with stratification on postmenopausal hormone therapy (HT) use. RESULTS: In cross-sectional analyses, mono-3-carboxypropyl phthalate and the sum of di-isobutyl phthalate metabolites were inversely associated with total hip BMD among HT nonusers, but not among HT users. Longitudinal analyses showed greater declines in total hip BMD among HT nonusers and with highest concentrations of mono-3-carboxyoctyl phthalate (-1.80%; 95% CI, -2.81% to -0.78%) or monocarboxynonyl phthalate (-1.84%; 95% CI, -2.80% to -0.89%); similar associations were observed with femoral neck BMD. Among HT users, phthalate biomarkers were not associated with total hip or femoral neck BMD change. CONCLUSION: Certain phthalate biomarkers are associated with greater percentage decreases in total hip and femoral neck BMD. These findings suggest that phthalate exposure may have clinically important effects on BMD, and potentially fracture risk.