Laparoscopically confirmed endometriosis and midlife plasma markers of inflammation, cholesterol, and adipokines among participants in the Nurses' Health Study II.

OBJECTIVE

Endometriosis may increase the risk of cardiovascular disease, possibly through a detrimental impact on circulating biomarkers. However, there is a paucity of research on endometriosis and inflammation, lipids, and adipokines at midlife.

METHODS

We used generalized linear models to determine the association between laparoscopically confirmed endometriosis and log-transformed levels of plasma C-reactive protein (n = 3936), interleukin-6 (n = 3495), tumor necrosis factor-alpha receptor 2 (n = 2967), high-density lipoprotein cholesterol (n = 1533), low-density lipoprotein cholesterol (n = 1324), total cholesterol (n = 4898), leptin (n = 2480), and adiponectin (n = 4262) among participants with existing biomarker measurements in the Nurses' Health Study II (average age 44 years). We investigated heterogeneity by body mass index (<25 kg/m vs. ≥ 25 kg/m).

RESULTS

We did not observe associations between endometriosis and midlife inflammatory biomarkers (C-reactive protein % difference: -4.6, 95 % CI [-15.7,7.9]; interleukin-6: -0.4 % [-7.2,7.1]; tumor necrosis factor-alpha receptor 2: -1.3 % [-4.1,1.6]) or levels of high-density lipoprotein cholesterol (0.8 % [-3.7,5.6]), low-density lipoprotein cholesterol (-0.2 % [-5.2,5.1]), total cholesterol (1.0 % [-0.7,2.7]), or adiponectin (-4.0 [-8.8,1.0]). Women with endometriosis had higher leptin levels (9.0 % [0.5, 18.1]). Associations varied by body mass index for total cholesterol (p-value 0.05) and leptin (p-value 0.02). Among women with a body mass index ≥25 kg/m, those with endometriosis had a mean total cholesterol level that was 2.7 % higher (0.2,5.2) than among those without; among those with a body mass index <25 kg/m, those with endometriosis had a mean leptin level that was 15.7 % higher (4.6, 28.1) than among those without endometriosis.

CONCLUSIONS

Endometriosis was not associated with midlife systemic inflammation, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, or adiponectin. Endometriosis was associated with higher leptin among those with a body mass index <25 kg/m and higher total cholesterol among those with a body mass index ≥25 kg/m. These findings suggest that endometriosis may influence cardiovascular disease risk via midlife cholesterol and leptin.