The burden of endometriosis on quality of life in Danish women: an analysis of the Danish Blood Donor Study

Abstract Background Endometriosis is a complex condition with a wide range of comorbidities. It is widely underdiagnosed, with a diagnostic delay of 4 to 10 years, potentially leading to worsened disease progression and a higher burden of comorbidities affecting quality of life. Understanding the link between endometriosis and its comorbidities is essential for improving early detection of the disease. Methods We analysed data from 953 women with a clinical diagnosis of endometriosis and 23,652 age-matched female controls enrolled in the Danish Blood Donor Study, using a case-control design. Participants completed one to four questionnaires covering a wide range of potential comorbidities; genetic data were available for a subset of participants. First, we compared the potential comorbidities between women with endometriosis and controls. Next, we investigated whether a polygenic score (PGS) for endometriosis was associated with those comorbidities. Lastly, we investigated whether women with a high genetic burden of endometriosis (highest PGS decile) experienced similar comorbidities to those diagnosed with endometriosis. Results Women with endometriosis experienced challenges in conception, gastrointestinal symptoms, and disturbed sleep patterns, compared to age-matched controls. The endometriosis PGS showed to be a predictor for endometriosis (OR per unit PGS = 1.43, 95% CI = 1.32–1.55). Gastrointestinal symptoms were also nominally associated with the endometriosis PGS, suggesting shared genetic pathways. Women without a diagnosis of endometriosis but with a high genetic burden of endometriosis did not suffer from the same wide range of comorbidities as women diagnosed with endometriosis. Conclusions Our findings highlight the complex genetic and clinical relationships between endometriosis and its comorbidities, emphasizing the need for future research investigating potential endometriosis subtypes.