Understanding the Associations of Prenatal Androgen Exposure on Sleep Physiology, Circadian Proteins, Anthropometric Parameters, Hormonal Factors, Quality of Life, and Sex Among Healthy Young Adults: Protocol for an International, Multicenter Study (Preprint)

Abstract

UNSTRUCTURED Background The ratio of second finger length to fourth finger length (2D:4D) is considered to be a negative correlate of prenatal androgen exposure and a positive correlate of prenatal oestrogen. Therefore males, on average, have a lower value of 2D:4D ratio as compared to females. Coincidentally, various brain regions are sensitive to prenatal androgen exposure, and their function in adulthood may be influenced by these prenatal actions of sex hormones. An example of such a brain region is the preoptic area which is involved in sleep and sexual functions. The objective of this study is to assess the relationship between prenatal androgen exposure (indicated by the 2D:4D ratio) and various physiological (sex hormone levels, sleep-wake parameters), psychological (mental health), as well as sexual parameters in young healthy adults. Methods The study consists of two phases: 1. In Phase I, we will conduct a survey-based study and anthropometric assessments (including 2D:4D ratio, body mass index) in healthy young adults. Using validated questionnaires, we will collect self-report data on sleep quality, sexual function, sleep chronotype, anxiety and depressive symptoms. 2. In Phase II, a sub-sample of Phase I will have polysomnography, physiological and genetic assessments. The sample recruited to this phase will comprise 100 healthy adults in each institution involved. Sleep architecture data will be obtained using a portable polysomnography. Venous blood will be drawn before and after polysomnograpy night and urine sample will be obtained in the morning. The level of testosterone, estradiol, progesterone, luteinizing hormone, follicle stimulating hormone, prolactin, melatonin and circadian regulatory proteins (CLOCK, TIM, PER) and a few miRNAs expression level, will be measured. The rest and activity cycle will be monitored using an actigraphy for a 7 days period. Discussion The impact of the study may help to better understand the role of plausible prenatal androgen exposure on sleep physiology, mental health and sexual quality of life in young adults.