The menstrual cycle associated with insomnia in newly employed nurses performing shift work: a 12-month follow-up study
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This study aimed to investigate whether insomnia among newly-employed shift-working nurses is associated with menstrual cycle irregularity.
We followed 287 nurses employed between 2015 and 2016 for 12 months. An Insomnia Severity Index (ISI) was completed to determine levels of insomnia 6 months after beginning work. At baseline and at 12-month follow-up, menstrual cycle information was obtained using clinical interviews. We analyzed baseline data separately by prevalence (participants with menstrual irregularity, n = 287) and incidence (participants with no reported menstrual irregularity, n = 238).
In a multivariate logistic regression analysis, including age, body mass index, and physical activity, insomnia was associated with a 2.05-fold increase in the odds of newly developing menstrual cycle irregularity compared with not having insomnia [odds ratio (OR) 2.05, 95% confidence interval (CI) 1.12–3.77]. Insomnia was associated with a 3.05-fold increase in the prevalence of menstrual cycle irregularity compared with not having insomnia (OR 3.05, 95% CI 1.81–5.13). As the ISI score increased, both the incidence and prevalence odds of menstrual cycle irregularity tended to increase.
Insomnia can induce menstrual cycle irregularity among nurses working shifts, and insomnia may have an important role in the pathway from shift work to menstrual dysfunction, aside from the possible effects of circadian rhythm disruption.
KeywordsSleep disturbance Menstruation Menstrual cycle irregularity Infertility Shift worker Circadian rhythm
We thank all of the members of the health promotion center at Chonnam National University Hwasun Hospital. We also thank the company and workers for their participation. WY and WJ designed the study, and analyzed and interpreted the data. WY drafted the first manuscript, and WJ made revisions. WY had the initial idea for this study. HM and JS recruited study participants and obtained medical data. KH was involved in data management and data interpretation. The authors have no competing interests to declare. This study received no funding.
This study received no funding.
Compliance with ethical standards
Conflict of interest
The authors have no competing interests to declare.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.
- Akerstedt T (1985) Adjustment of physiological and circadian rhythms and the sleep-wake cycle to shift work. In: Folkard S, Monk TH (eds) Hours of work: temporal factors in work scheduling. John Wiley, Chichester, United Kingdom, pp 185–198Google Scholar
- Baumgartner A, Dietzel M, Saletu B, Wolf R, Campos-Barros A, Gräf KJ et al (1993) Influence of partial sleep deprivation on the secretion of thyrotropin, thyroid hormones, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone, and estradiol in healthy young women. Psychiatry Res 48:153–178CrossRefGoogle Scholar
- Centers for Disease Control and Prevention [Internet] (2018) Physical activity. physical activity basics; [cited 2018 Jan 22]. http://www.cdc.gov/physicalactivity/basics/adults/index.htm
- Douglas NC, Lobo RA (2016) Reproductive endocrinology. In: Lobo RA, Gershenson D, Lentz G, Valea F (eds) Comprehensive gynecology, 7th edn. Elsevier, Amsterdam, pp 77–107Google Scholar
- Glymour MM, Greenland S (2008) Causal diagrams. In: Rothman KJ, Greenland S, Lash TL (eds) Modern epidemiology, 3rd edn. Lippincott Williams & Wilkins, Philadelphia, pp 183–209Google Scholar
- John CM (2016) The menstrual cycle and disorders of ovulation. In: Jameson JL, De Groot LJ (eds) Endocrinology: adult and pediatric, 7th edn. Elsevier, Amsterdam, pp 2231–2241 lnGoogle Scholar
- Park T (2017) Samsung semiconductor worker is first case of female infertility recognized as industrial accident; 2018 [cited 2018 Jan 22]. http://english.hani.co.kr/arti/english_edition/e_business/787230.html
- Roth T (2007) Insomnia: definition, prevalence, etiology, and consequences. J Clin Sleep Med 3(5 Suppl):S7–S10Google Scholar