C-reactive protein-triglyceride–glucose index associated with high incident endometriosis: BMC study

A new study published in the journal of BMC Women's Health found that there is a favorable correlation between the prevalence of endometriosis (EM) and the C-reactive protein–triglyceride glucose index (CTI).

About 10% of women of reproductive age have endometriosis which is a benign gynecological condition marked by the formation of endometrioid tissue outside the uterine cavity. Laparoscopy-guided biopsy is the conventional procedure for identifying endometriosis; however, it sometimes results in considerable delays in diagnosis, usually lasting between 6 and 11 years. To increase diagnostic sensitivity and accuracy and, eventually, improve patient quality of life, new diagnostic techniques and predictive biomarkers must be developed.

An innovative and promising tool for assessing the degree of inflammation is the C-reactive protein (CRP)–triglyceride (TG)–glucose index (CTI). Endometriosis is a common, estrogen-influenced chronic inflammatory disease that mostly affects women who are of reproductive age. Yet, no research has shown a connection between EM and CTI. Thereby, to provide strong evidence in favor of this correlation, Yanan Ren and her team set out to investigate the connection between endometriosis and CTI by examining data from the National Health and Nutrition Examination Survey (NHANES, 1999–2006).

Data from the National Health and Nutrition Examination Survey (NHANES) 1996–2006 was used in this cross-sectional study to include females aged 20 to 50. These women self-reported having EM and had enough information to compute the CTI, which is calculated as 0.412 × ln (C-reactive protein [CRP]) + ln (triglycerides [mg/dL] × fasting plasma glucose [mg/dL]/2). The relationship between the CTI and EM was investigated using subgroup analysis, limited cubic splines, and multivariate logistic regression.

A total of 2235 women were included in this study where the CTI was strongly correlated with the occurrence of EM, and those with EM tended to have greater CTI. A 56% increase in the occurrence of EM was linked to a 1 mg/dL increase in CTI in Model 1.

Both Model 2 and Model 3 showed this correlation to be significant. Interestingly, the prevalence of EM was significantly greater in those in the top tertile of residual cholesterol than in those in the lowest tertile. A nonlinear positive correlation between CTI and the occurrence of EM was found using restricted cubic splines.

Also, individuals who were older than 40, had a body mass index of 25 kg/m2, smoked 100 cigarettes or more, were married or cohabitating, and used oral contraceptives had higher EM prevalence with CTI. Overall, the findings suggest that EM and CTI were positively correlated in American women. The application of the CTI as an inflammatory indicator may offer fresh perspectives on EM management and prevention.

Source:

Ren, Y., Xu, R., Zhang, J., Jin, Y., Zhang, D., Wang, Y., & Su, L. (2025). Association between the C-reactive protein-triglyceride–glucose index and endometriosis: a cross-sectional study using data from the national health and nutrition examination survey, 1996–2006. BMC Women's Health, 25(1). https://doi.org/10.1186/s12905-024-03541-x