High levels of physical activity are associated with a lower occurrence of heavy menstrual bleeding: Data from a large population-based cohort study

Introduction:
Heavy menstrual bleeding (HMB) is a common gynaecological problem that affects a quarter of the female population. HMB negatively impacts on physical, emotional and social quality of life and it is also associated with loss of productivity. While HMB is a highly prevalent problem in women, the role of physical activity (PA) on HMB, and its effect on moderating the association between BMI and HMB are not well understood. The aim of this study was therefore to investigate individual and combined associations between PA and BMI with self-reported HMB over 15 years in young adult women.

Methods:
Participants (22-27 years in 2000; N=10618) in The Australian Longitudinal Study of Women’s Health (ALSWH) completed seven surveys from 2000 to 2015. They reported PA, weight and height and the frequency of HMB (never; rarely; sometimes; or often) in every survey from 2000 to 2015. BMI was calculated from self-reported weight and height. The individual and combined associations between PA and BMI with HMB from 2000 to 2015 were investigated using generalised estimating equation models.

Results:
In 2000, when women were aged 22 to 27 years, the prevalence of HMB was 15.9%. This prevalence doubled after 15 years and it was consistently highest in women in the lowest PA category (<3.33 MET.mins/week). Women who reported high levels of PA (>1000 MET.mins/week) had 10% lower odds [Odds Ratio (OR): 0.90; 95%Confidence Interval (95%CI): 0.82-0.98] of HMB than women who reported no PA. The prevalence of HMB by BMI levels over 15 years was highest in women who were obese. Women who were overweight and obese had higher odds [overweight: OR 1.15, (95%CI 1.07-1.23); obese: OR 1.37, (95%CI 1.26-1.49)] of HMB than women with healthy weight. There was a 19% [OR 0.81, (95%CI 0.68-0.97)] reduction in the odds of HMB in women who reported high levels of PA and were obese.

Discussion:
While BMI is positively associated with HMB, the adverse effects of high BMI on HMB were attenuated by high levels of PA (>1000 MET.mins/week). PA is not usually a first-line treatment for HMB, but it is a key factor in the maintenance of healthy BMI in young women. Findings of this study suggest that promotion of PA at this life stage is important for reproductive health.

Conflict of interest statement:
My co-authors and I acknowledge that we have no conflict of interest of relevance to the submission of this abstract.