The relation between body mass index and primary dysmenorrhea: A systematic review and meta-analysis

The relation between body mass index (BMI) categories and the occurrence of primary dysmenorrhea has been investigated, but the results of these studies are inconsistent and controversial. The aim of our study was to systematically review the literature and investigate the association between each category of BMI and the occurrence of primary dysmenorrhea.

We conducted a systematic review and meta-analysis of observational studies related to BMI and primary dysmenorrhea. Eleven databases-PubMed, Medline, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), Chinese Science and Technology Periodical Database (VIP), Chinese Biomedical Literature Database (CBM), and Wanfang database-were systematically searched from inception to March 2022. We used the 11 items recommended by the Agency for Healthcare Research and Quality to assess the quality of included studies. The Q test and the I² test were used to evaluate the heterogeneity among studies. Odds ratios (OR) and their 95% confidence intervals (CI) were pooled by fixed-effects models or random-effects models. Stata software version 16.0 was used to complete the statistical analyses.

A total of 4181 articles were collected from the database, and 12 studies were included based on inclusion and exclusion criteria. A total of 29 647 participants were included in the study, with a mean baseline age of 17-45 years. All included literature was published between 2017 and 2021 and was conducted in six countries. Eleven included studies were of medium quality and one included study was of high quality. Being underweight may be related to the occurrence of primary dysmenorrhea (12 studies, n = 6545, OR 1.43, 95% CI 1.18-1.73). Being overweight (12 studies, n = 3098) and obesity (four studies, n = 94) may not be associated with the development of primary dysmenorrhea.

Being underweight may increase the risk of the occurrence of primary dysmenorrhea, whereas overweight and obesity might not be associated with primary dysmenorrhea. Due to the limitations of the meta-analysis, more studies are needed to investigate the relation between each category of BMI and the occurrence of primary dysmenorrhea. To maintain a balanced diet and an appropriate lifestyle is beneficial for people to have the normal category of BMI and live a healthy life, which may play a role in preventing the occurrence of primary dysmenorrhea.