- Early menopause may be exacerbated by rotating night shifts.
Why this matters
- Early age at menopause has been associated with increased risk for cardiovascular disease, osteoporosis, and cognitive decline.
- Late age at menopause has been associated with increased risk for breast and endometrial cancer.
- Night work has been associated with changes in ovulation and preterm labor.
- 61% reported working rotating night shifts, with a mean cumulative duration of 70.5 months prior to 1989.
- 38% reported working rotating night shifts, with a mean cumulative duration of 36.9 months between 1989 and 2011.
- As women aged, their mean cumulative duration decreased (8% at >50 years vs 23% at
- Women with ≥10 months of rotating night shift work in the previous 2-year interval had an increased risk for early menopause (multivariable adjusted HR, 1.09; 95% CI, 1.02-1.16).
- Prospective cohort study.
- Cohort identified from the Nurses' Health Study 2 (n=80,840).
- Women with rotating night shift work (working nights concurrently with evenings and/or days).
- Questionnaires used to assess cumulative months of rotating night shifts and age at natural menopause.
- Funding: CDC; National Institute for Occupational Safety and Health; NIH.
- Self-reporting bias possible.