Early menstruation increases the likelihood of hot flushes and nights sweats decades later at menopause, according to a University of Queensland study.
School of Public Health researchers analysed data from more than 18,000 middle aged women across the UK, USA and Australia, as part of the Life course Approach to reproductive health and Chronic disease Events (InterLACE) international collaboration.
UQ's Dr Hsin-Fang Chung said the study showed women who started menstruating aged 11 or younger had a 50 per cent higher risk of experiencing frequent hot flushes and night sweats - known as vasomotor symptoms - at menopause.
The group was compared with women who had their first period at 14 or older.
"The risk of the women who menstruated early experiencing both symptoms was greater than having either hot flushes or night sweats alone," Dr Chung said.
She said early menstruation previously had been linked to adverse health conditions later in life, including type 2 diabetes and cardiovascular diseases.
InterLACE project leader Professor Gita Mishra said obesity played a significant role in the findings.
"Women who experienced early menstruation and were overweight or obese in midlife had a two times greater risk of frequent hot flushes and night sweats, compared with women who experienced their first period aged 14 years or older, and had normal weight," she said.
"These findings encourage women with early menstruation to engage in health promotion programs, especially weight management in adulthood," Professor Mishra said.
To examine the association between age at menarche and risk of vasomotor menopausal symptoms (VMS) and whether midlife body mass index (BMI) modified the association.
A pooled analysis of six cohort studies.
The International collaboration on the Life course Approach to reproductive health and Chronic disease Events (InterLACE).
18 555 women from the UK, USA and Australia.
VMS frequency data (never, rarely, sometimes and often) were harmonised from two studies (n = 13 602); severity data (never, mild, moderate and severe) from the other four studies (n = 4953). Multinominal logistic regression models were used to estimate relative risk ratios (RRRs) and 95% CIs adjusted for confounders and incorporated study as random effects.
Main outcome measures
Hot flushes and night sweats.
Frequency data showed that early menarche ≤11 years was associated with an increased risk of ‘often’ hot flushes (RRR 1.48, 95% CI 1.24–1.76) and night sweats (RRR 1.59, 95% CI 1.49–1.70) compared with menarche at ≥14 years. Severity data showed similar results, but appeared less conclusive, with RRRs of 1.16 (95% CI 0.94–1.42) and 1.27 (95% CI 1.01–1.58) for ‘severe’ hot flushes and night sweats, respectively. BMI significantly modified the association as the risk associated with early menarche and ‘often’ VMS was stronger among women who were overweight or obese than those of normal weight, while this gradient across BMI categories was not as strong with the risk of ‘severe’ VMS.
Early age at menarche is a risk factor for VMS, particularly for frequent VMS, but midlife BMI may play an important role in modifying this risk.
H‐F Chung, D Zhu, AJ Dobson, D Kuh, EB Gold, SL Crawford, NE Avis, ES Mitchell, NF Woods, DJ Anderson, GD Mishra. Age at menarche and risk of vasomotor menopausal symptoms: a pooled analysis of six studies.
First published: BJOG 21 July 2020 https://doi.org/10.1111/1471-0528.16393