Dietary Inflammatory Index score and risk of developing endometriosis: A case–control study

The possible relationship between chronic inflammation from dietary exposure and endometriosis has not been investigated. Thus, the aim of this study was to investigate the association between the Dietary Inflammatory Index (DII®) and endometriosis. Women with endometriotic lesions were defined as cases (n = 59), and controls (n = 59) had no visible ectopic endometrium sites. Body mass index (BMI=weight(kg)/height(m)2) was calculated from measured height and weight and waist circumference was measured. A validated semi-quantitative food frequency questionnaire was used to calculate the DII score. Women with endometriosis were younger, thinner; and had a more pro-inflammatory diet and more pain (dysmenorrhea, chronic pelvic pain, deep dyspareunia), than controls. Women with higher DII scores (>0.86) were more likely to have endometriosis and to present with dyspareunia. Results obtained from modeling DII as a categorical variable in relation to risk of endometriosis showed a near tripling of risk (OR = 2.77; 95% CI = 1.13–6.77) for women with DII >0.86 versus those with DII ⩽ 0.86, after adjusting for age and BMI. After multivariable adjustment, women with DII > 0.86 were four times more likely to have endometriosis compared to women with DII ⩽ 0.86 (OR = 4.14; 95% CI= 1.50–11.4). In conclusion, a pro-inflammatory diet was significantly associated with endometriosis.