Increased dioxin-like compounds in the serum of women with peritoneal endometriosis and deep endometriotic (adenomyotic) nodules.

OBJECTIVE: To investigate the possible association between the body burden of dioxin-like compounds and endometriotic disease.
DESIGN: Case-control study.
SETTING: Gynecology ward in a university hospital. PATIENT(S): Seventy-one women with peritoneal endometriosis (n = 25) or deep endometriotic (adenomyotic) nodules (n = 25) and controls (n = 21). INTERVENTION(S): Collection of 200 mL of blood (fasted) and face-to-face interview. MAIN OUTCOME MEASURE(S): Assessment of dioxin (PCDD), furan (PCDF), and dioxin-like PCB serum concentrations (picograms toxic equivalent [TEQ]/g lipids). RESULT(S): Age and body mass index were traced by linear multiple regression as determinants of total TEQ levels. After standardization for these variables (30 years and 22.5 kg/m2), the mean TEQ levels were 24.21 (controls), 30.62 (peritoneal endometriosis), and 37.60 (deep endometriotic [adenomyotic] nodules) pg TEQ/g lipids. Logistic regression analysis indicated a significantly increased risk of deep endometriotic (adenomyotic) nodules (odds ratio [OR], 3.3; 95% confidence interval [CI], 1.4-7.6) for an increment of 10 pg in total TEQ levels/g lipids. An increased risk was also found for peritoneal endometriosis (OR, 1.9; 95% CI, 0.9-3.8) for total TEQ levels and for dioxins alone (OR, 3.2; 95% CI, 1.0-9.9). CONCLUSION(S): The results provide the first epidemiological evidence of an association between increased PCDD/PCDF and PCB body burden and endometriosis.