The Relation between Caffeine Consumption and Endometriosis: An Updated Systematic Review and Meta-Analysis.

Konstantinos S Kechagias,Konstantinos Katsikas Triantafyllidis,Maria Kyrgiou,Panagiotis Giannos,Ilkka Kalliala,Maria Paraskevaidi,Margarita Kyriakidou,Areti Angeliki Veroniki

doi:10.3390/nu13103457

Abstract

While the contributing factors leading to endometriosis remain unclear, its clinical heterogeneity suggests a multifactorial causal background. Amongst others, caffeine has been studied extensively during the last decade as a putative contributing factor. In this systematic review and meta-analysis, we provide an overview/critical appraisal of studies that report on the association between caffeine consumption and the presence of endometriosis. In our search strategy, we screened PubMed and Scopus for human studies examining the above association. The main outcome was the relative risk of endometriosis in caffeine users versus women consuming little or no caffeine (<100 mg/day). Subgroup analyses were conducted for different levels of caffeine intake: high (>300 mg/day) or moderate (100–300 mg/day). Ten studies were included in the meta-analysis (five cohort and five case-control studies). No statistically significant association was observed between overall caffeine consumption and risk for endometriosis (RR 1.12, 95% confidence interval (CI) 0.97–1.28, I2 = 70%) when compared to little or no (<100 mg/day) caffeine intake. When stratified according to level of consumption, high intake was associated with increased risk of endometriosis (RR 1.30, 95%CI 1.04–1.63, I2 = 56%), whereas moderate intake did not reach nominal statistical significance (RR 1.18, 95%CI 0.99–1.40, I2 = 37%). In conclusion, caffeine consumption does not appear to be associated with increased risk for endometriosis. However, further research is needed to elucidate the potential dose-dependent link between caffeine and endometriosis or the probable role of caffeine intake as a measurement of other unidentified biases.

Highlights

Endometriosis is a common disorder defined as the presence of endometrial tissue outside the uterine cavity [1]
The majority of the studies (10/13) explored caffeine as part of a number of risk factors that associated with endometriosis in women with and without disease
Caffeine consumption was based on the intake of caffeine containing beverages, in four studies, caffeine consumption was based on coffee intake only, and in three studies, beverage type was not defined

Summary

Introduction

Endometriosis is a common disorder defined as the presence of endometrial tissue (glandular cells and stroma) outside the uterine cavity [1]. The most common sites of endometriosis include the pelvic peritoneum, the ovaries, and the uterosacral ligaments. Women with endometriosis may be asymptomatic or suffer from subfertility, pelvic pain, and dyspareunia [2]. While the definitive cause of endometriosis constitutes a matter of debate, its clinical heterogeneity suggests a multifactorial causal background that consists of both genetic and environmental factors [4]. During the last two decades, several studies have correlated endometriosis with modifiable risk factors, such as food intake and lifestyle habits, given their potential influence on hormonal levels, immune response, and inflammatory activity [5,6,7]

Results

Discussion

Conclusion