The association between activity patterns and malignant neoplasms of female genital organs: a prospective cohort study of UK biobank.

OBJECTIVE

The role of physical activity timing in the development and progression of malignant neoplasms of the female reproductive system remains to be elucidated. Malignant neoplasms of female genital organs include those of the vulva, vagina, cervix, uterine corpus, uterus (part unspecified, site not further defined), ovaries, placenta, and other unspecified sites. This study aimed to investigate the association between patterns of physical activity and the risk of malignant neoplasms of the female reproductive system.

METHODS

This study was reported in accordance with the STROBE guidelines for observational cohort studies. This research has been conducted using the UK Biobank Resource under Application ID: 103547. This study included 49,540 female participants with valid accelerometer data from the UK Biobank at baseline. Physical activity patterns were defined based on the timing of moderate-to-vigorous physical activity (MVPA) occurrence throughout the day. According to the timing of MVPA, participants were categorized into four groups: morning, evening, mixed-time, and midday-afternoon groups, with the morning group serving as the reference. Cox proportional hazards models were employed to analyze the association between physical activity patterns and the incidence of malignant neoplasms of female genital organs.

RESULTS

During a median follow-up of 12.6 years, 419 incident cases of malignant neoplasms of female genital organs were recorded. After adjusting for potential confounding factors, compared to women who engaged in morning exercise, those in the evening and mixed-time groups exhibited a significantly higher risk of developing reproductive system malignancies (Evening group: hazard ratio [HR] = 1.530, 95% confidence interval [CI]: 1.006-2.326; Mixed-time group: HR = 1.406, 95% CI: 1.026-1.928; P for trend <0.05).

CONCLUSIONS

Compared to the morning group, engaging in MVPA during the evening or at mixed times was associated with an elevated risk of malignant neoplasms of the female reproductive system. This association was not observed in the midday-afternoon group. Furthermore, no statistically significant associations were found between activity patterns and specific types of female genital organ malignancies.