Effects of night shift on plasma concentrations of melatonin, LH, FSH and prolactin, and menstrual irregularity.

Miyauchi, Fumihisa; Nanjo, K; Otsuka, Kyoichi

doi:10.1539/joh1959.34.545

Cited by 38 publications

(25 citation statements)

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“…Because we did not observe differences in urinary estrogen levels between the night and day shift groups but did observe such differences within the night shift workers, it is possible that the effect of night shift work on estrogen levels is too small (or, conversely, the variability in estrogen levels is too great) to detect differences between the 2 groups. At least 4 other studies have investigated the effect of night shift work and/or exposure to light-atnight on levels of reproductive hormones (80)(81)(82)85). Two studies reported increased serum estradiol levels associated with either not being asleep by 1:00 am (82) or longer durations of night shift work (80); however, neither study analyzed FSH or LH levels.…”

Section: Discussionmentioning

confidence: 99%

Night Shift Work and Hormone Levels in Women

Davis

Mirick

Chen

et al. 2012

Cancer Epidemiology, Biomarkers &Amp; Prevention

109

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Background: Night shift work may disrupt the normal nocturnal rise in melatonin, resulting in increased breast cancer risk, possibly through increased reproductive hormone levels. We investigated whether night shift work is associated with decreased levels of urinary 6-sulfatoxymelatonin, the primary metabolite of melatonin, and increased urinary reproductive hormone levels.Methods: Participants were 172 night shift and 151 day shift-working nurses, aged 20-49 years, with regular menstrual cycles. Urine samples were collected throughout work and sleep periods and assayed for 6-sulfatoxymelatonin, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and estrone conjugate (E1C).Results: 6-Sulfatoxymelatonin levels were 62% lower and FSH and LH were 62% and 58% higher, respectively, in night shift-working women during daytime sleep than in day shift-working women during nighttime sleep (P 0.0001). Nighttime sleep on off-nights was associated with 42% lower 6-sulfatoxymelatonin levels among the night shift workers, relative to the day shift workers (P < 0.0001); no significant differences in LH or FSH were observed. 6-Sulfatoxymelatonin levels during night work were approximately 69% lower and FSH and LH were 35% and 38% higher, compared with day shift workers during nighttime sleep. No differences in E1C levels between night and day shift workers were observed. Within night shift workers, 6-sulfatoxymelatonin levels were lower and reproductive hormone levels were higher during daytime sleep and nighttime work, relative to nighttime sleep (P < 0.05).Conclusions: These results indicate that night shift workers have substantially reduced 6-sulfatoxymelatonin levels during night work and daytime sleep and that levels remain low even when a night shift worker sleeps at night.Impact: Shift work could be an important risk factor for many other cancers in addition to breast cancer. MeSH Subject Headings: breast cancer, shift work, circadian rhythm, environmental carcinogens, estrogen, melatonin, 6-sulfatoxymelatonin, pineal. Cancer Epidemiol Biomarkers Prev; 21(4); 609-18. Ó2012 AACR.

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Section: Discussionmentioning

confidence: 99%

Night Shift Work and Hormone Levels in Women

Davis

Mirick

Chen

et al. 2012

Cancer Epidemiology, Biomarkers &Amp; Prevention

109

View full text Add to dashboard Cite

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“…Hospital nurses engaged in shift work tend to have irregular menstruation 8) . Among all non-pregnant nurses who agreed to cooperate with this study, only six had regular menstrual cycles and could participate in the study as subjects.…”

Section: Discussionmentioning

confidence: 99%

“…On the night shift, the urinary aMT6s levels during night work were decreased, and its day/night difference became small. The melatonin secretion during night work is variable in literatures, i.e., unaltered 20) , or decreased 8) . The results by ANOVA in the present study evidently indicated that the urinary excretion rates of aMT6s during daytime and nighttime were affected by work shifts, and supported the latter.…”

Section: Amt6smentioning

confidence: 99%

“…Melatonin secretion is sensitive to light/dark cycle, and its secretion is suppressed at 500-800 lux 7,8) . This suppression is reflected in the urinary aMT6s level 5) .…”

Section: Amt6smentioning

confidence: 99%

“…Melatonin secretion is sensitive to light/ dark cycle, and has circadian rhythm having a peak level at 2-4 o'clock in the morning [5][6][7] . Serum or urinary melatonin has been used to assess the effects of work stress on biological rhythm in workers 8,9) . It is well known that catecholamines are sensitive to stimuli from the external environment and fluctuate with stress.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Night Work on Urinary Excretion Rates of 6-Sulfatoxymelatonin, Norepinephrine and Estriol in Pregnant Women.

Yamauchi

2004

INDUSTRIAL HEALTH

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It has been suggested that shift work, night work in particular, affects worker's psychophysical health. However, the effects of night work on the health of pregnant women are not physiologically well elucidated. The effects of night work on the biological function of pregnant women were studied in the present study. Three pregnant and six non-pregnant nurses that engaged in fastrotating shift system cooperated for the study. The 24-h urine samples were collected in two time frames, daytime (07:00 to 23:00) and nighttime (23:00 to 07:00) on the day shift, the night shift and the days off. Urinary concentrations of 6-sulfatoxymelatonin and norepinephrine were measured by enzyme-linked immunosorbent assay and estriol by radioimmunoassay. The excretion profiles of urinary 6-sulfatoxymelatonin in the pregnant and the non-pregnant women were altered on the night shift, which might relate the derangement of circadian rhythm of melatonin secretion. The urinary norepinephrine level during the night work was considerably higher in the pregnant women, which indicated the presence of higher physical burden in them due to the night work. The urinary estriol level was not significantly affected by shift, day/night and individual factors, and the effect of night work on urinary estriol level of the pregnant women remained uncertain. The results of the present study suggested that the night work of the pregnant shift workers should be much more relieved.

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IMPACT survey: IMpaired fecundity in Physicians and Association with Clinical Time

et al. 2020

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Objective Studies suggest female physicians experience higher rates of infertility than the general population. The overall objective of this study was to determine the rate of impaired fecundity in a sample of female emergency physicians and compare it to the Centers for Disease Control and Prevention (CDC) National Survey of Family Growth (NSFG) data. Impaired fecundity is defined as physical difficulty in getting pregnant or carrying a pregnancy to live birth. Methods We performed a cross‐sectional survey of female emergency physicians to determine the rate of impaired fecundity. Survey questions were adapted from the NSFG to allow comparison to the general population. Statistical comparisons were made using contingency tables (with chi‐square and tau‐c assessments), 1‐sample t tests, and independent samples t tests, as appropriate. Results A total of 2072 women completed the survey with a mean (SD) current age of 38.9 (7.2) years. Data were analyzed for women of childbearing years (15–44 years old as defined by the CDC; n = 1705 [82% total responses]). The rate of impaired fecundity in emergency physicians was 24.9% as compared to the NSFG cohort (12.1%; P < 0.001). Female emergency physicians with impaired fecundity reported working 9.8 overall more clinical hours (95% CI 2.5–17) and 4.5 more night hours (95% CI 0.8–8.2) than those with normal fecundity. Conclusion Female emergency physicians have increased rates of impaired fecundity when compared with a general population cohort. Clinical workload and night shifts are greater in female emergency physicians with impaired fecundity. Research is needed to elucidate work‐related impaired fecundity risk factors.

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Effects of night shift on plasma concentrations of melatonin, LH, FSH and prolactin, and menstrual irregularity.

Cited by 38 publications

References 0 publications

Night Shift Work and Hormone Levels in Women

Night Shift Work and Hormone Levels in Women

Effects of Night Work on Urinary Excretion Rates of 6-Sulfatoxymelatonin, Norepinephrine and Estriol in Pregnant Women.

IMPACT survey: IMpaired fecundity in Physicians and Association with Clinical Time

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