Men's Shift Worker Study

Seeking Men Who Work NIGHT SHIFT or DAY SHIFT in a Health Care Setting to Participate in a Study

Study Background
Eligibility Requirements
Compensation

Welcome to the Men's Shift Worker Study Website. Thank you for your interest in our study. The primary purpose of the Men's Shift Worker Study is to assess whether working night shifts changes the levels of melatonin, cortisol and male reproductive hormones in healthy men of reproductive age. Data collection methods include questionnaires and collecting urine and blood samples from 200 men currently working night shifts and from 150 men currently working day shifts. All information obtained for this study is kept strictly confidential.

Background and Rationale for the Study

There is increasing scientific interest in how environmental factors affect a person's normal circadian rhythm or 24-hour "biological clock." Disruption of circadian rhythm in humans, including the wake/sleep cycle, may affect endocrine function and the regulation of hormones most directly involved in the development of prostate cancer. Of particular interest is the potential influence of exposure to light-at-night, and sleep disruption on hormones.

Persons who engage in night shift work are subject to the influence of both factors, and as a result, may exhibit altered hormone profiles that could increase the risk of hormone-related diseases, including prostate cancer. Recent studies suggest that men who work shifts at night, leading to potential circadian disruption, exposure to light-at-night, and sleep deprivation, are at an increased risk of prostate cancer. To date, no studies have investigated the direct influence of working night shifts on reproductive hormone levels in men.

The primary objective of this study is to investigate whether working at night is associated with decreased levels of the urinary concentration of melatonin and increased levels of urinary and serum concentrations of reproductive hormones and stress hormones in healthy men of reproductive age.

Secondarily, this study will look at characteristics of sleep among night shift workers that are related to the hormone patterns identified. It is expected that this study will improve our understanding of the possible relationship between night shift work and prostate cancer, and will provide important new information regarding the underlying biological basis of the emerging evidence linking night shift work with prostate cancer risk.

Eligibility Requirements

• Male, 22-55 years of age
• Working in a hospital, laboratory, nursing home or other health care facility
• Working day or night shifts at least 20 hours per week
• Not currently taking steroids, hormones, or any type of recreational drug.

Compensation

Upon completion of the study, day shift workers will receive $150 and night shift workers will receive $200 for their efforts.

	Summary of Participation
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