EFFECT OF NIGHT SHIFT WORK ON ANTI-MULLERIAN HORMONE (AMH) LEVELS IN REPRODUCTIVE-AGED AFRICAN AMERICAN WOMEN (AAW)

Abstract

Circadian disruption, as commonly occurs in night shift workers, has been associated with adverse reproductive outcomes. Very few studies have examined the association between night shift work and ovarian reserve, and no prior studies have investigated this association in African American women (AAW). The objective of this study was to determine whether levels of AMH, a widely used serum biomarker of ovarian reserve, are associated with working night shift in a cohort of reproductive-aged AAW. Cross-sectional study This study utilized an established cohort of AAW from Detroit, MI aged 25 to 35 years old, who had been recruited as a part of the NIEHS Study of the Environment, Lifestyle and Fibroids. Anthropometric measurements, self-reported medical history, and serum AMH levels (picoAMH assay, Ansh Labs, Webster, TX) were analyzed. Multivariable linear regression models were used to estimate the impact of night shift work on AMH levels (SAS 9.4- Cary, NC). Models were adjusted for age, age2, body mass index, recent or current hormonal contraception use, and irregular menses (>35 days). AMH was log transformed for inclusion in the linear regression model. A total of 1,646 women were included in this analysis with an average age of 29.2±3.4 years old and a median AMH of 4.1 ng/mL (IQR 2.3-6.7). Of these women, 236 (14%) reported working night shifts, with an average of 113±97 night shifts worked per year, and a median AMH value of 3.74 (IQR 1.90-5.91). Adjusted models demonstrated that working night shift was significantly associated with lower AMH levels (-13.5%, 95% CI -23.9% to -1.7%, p=0.02). These findings suggest that ovarian reserve, as measured by serum AMH levels, is lower in reproductive-aged AAW who work night shifts than in those who do not work night shifts. Further research is needed to establish the mechanistic link between disruptions in circadian rhythm and decreased ovarian reserve. Providers should have an understanding of the factors that impact ovarian reserve in a diverse cross-section of women, as this will improve our ability to provide personalized recommendations and empowers all patients to make informed reproductive choices.