In study results published in the article "The association between shift work exposure and the variations in age at natural menopause among adult Canadian workers: results from the Canadian Longitudinal Study on Aging (CLSA)."
Over the past few years, shift work has become more prevalent throughout the world, with an estimated 20 percent of people who are economically active in North America and Europe working some kind of irregular or alternate shifts. To meet the growing demand for products and services, shift employment has become economically necessary, but it comes with some health hazards.
Previous research has connected shift employment to an increased risk of coronary events, with night shifts having the highest risk. Peptic ulcers, type 2 diabetes, and malignancies like prostate, colorectal, and breast are further associated health issues. Although there hasn’t been much research on how shift work affects older and middle-aged people.
Middle-aged and older women should be especially cautious about their age of menopause because both early and late menopause may be a significant risk factor for future morbidity and mortality. Smoking, parity, and socioeconomic level are examples of environmental factors that have been previously found to be highly related to variations in age at natural menopause.
As prospective effects of circadian rhythm disruption on ovulation and fertility have been identified by earlier studies. It has been proven that prolonged exposure to artificial light during the nighttime suppresses melatonin, which then disturbs ovarian activity.
Little research has been done so far on the connection between shift work and age at menopause naturally.
This new study sought to determine the relationship between shift work exposure and variations in age at natural menopause in adult Canadian employees. It was based on secondary data analyses of over 3,700 premenopausal women. Rotating shifts have been linked to a considerable delay in the start of menopause, according to study findings. Though more research is needed, the researchers hypothesise that disrupted circadian rhythms may be involved.
“This study shows a potential influence of circadian regulation on age at natural menopause, with current rotating shift work linked to later age at menopause and current night shift work linked to earlier age at menopause. Whether these differences in age at menopause are directly related to the effect of circadian rhythm changes on underlying hypothalamic regulation or are because of other sociodemographic factors such as chronic stress, economic insecurity, and substance use or abuse requires further study,” says Dr. Stephanie Faubion, NAMS medical director.
Parvathy Sukumaran 
