0343 Associations of Endogenous Hormones and Phthalate Exposure with Subjective and Objective Sleep Measures in Midlife Women

Abstract

Abstract Introduction Impaired sleep during the menopausal transition reduces quality of life and increases risk of multiple diseases. The changing hormonal milieu during midlife is associated with impaired sleep. Endocrine disrupting chemicals, such as phthalates, may also contribute to the increased prevalence of sleep disturbances in midlife women. Phthalates are known to impact the endogenous hormones associated with sleep. However, the link between phthalate exposure and sleep quality remains unexplored. Methods We recruited 26 midlife women (median age 50 years) through the Carle Regional Sleep Disorders Center in Urbana, Illinois. Subjective sleep was assessed through the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and self-reported frequency of sleep disturbances, insomnia, and restless sleep. Objective sleep was measured using actigraphy and manual sleep logs (7-day average). Serum levels of follicle-stimulating hormone, estradiol, progesterone, testosterone, free estradiol, and free testosterone were quantified using ELISAs from a single sample from each participant. Phthalate metabolites were quantified from urine using high performance liquid chromatography-mass spectrometry (HPLC-MS). Covariates, including depression, hot flashes, quality of life, demographics, and lifestyle factors, were measured via surveys. Results Preliminary unadjusted logistic regression was used to determine the association between hormone values and subjective sleep quality binomial variables, including daytime sleepiness, sleep efficiency, sleep onset latency, sleep duration, number of sleep disturbances, and frequency of sleep disturbances. Each of these subjective sleep measures is significantly associated with one or more hormones. Conclusion Our results are consistent with literature identifying associations between hormones and subjective sleep in midlife women. Additional analyses will determine associations between hormones and objective sleep, and phthalates with both subjective and objective sleep measures. Excitingly, our study will be among the first to investigate the association between endocrine disruption and sleep quality in this population. Support Carle Illinois Seed Grant Program