Endometriosis and Microvascular Dysfunction: Role of Inflammation

Endometriosis is an estrogen-dependent gynecological disorder associated with considerable chronic pelvic pain, pain during intercourse, and is a major cause of infertility. This disorder affects 6% - 10% of reproductive age women and can be as high as 35-50% in women experiencing pain or infertility. Endometriosis derives from the presence of endometrium-like tissue in sites outside the uterine cavity. While endometriosis is a local inflammatory syndrome, the inflammatory process is systemic.

Endometriosis is associated with higher risk of hypercholesterolemia and hypertension 8. Epidemiologic data demonstrate a clear association between endometriosis, reproductive risk factors, inflammation and cardiovascular (CV) risk.

Endometriosis a disease of inflammation and increased systemic inflammatory cytokine production, although the precise mechanisms by which localized lesion results in systemic inflammation are incompletely understood. Published data confirm an elevation of several inflammatory cytokines in the circulation of women with endometriosis. Alterations in circulating miRNAs specific to endometriosis are one mechanism causing immune dysfunction and subsequent increased cytokine expression in areas remote from the endometriotic lesions. This aberrant increase in systemic cytokine production is a highly plausible putative link to accelerated vascular dysfunction and atherosclerosis in women with endometriosis.

The circulating factors LDL and oxidized LDL are two of the many biomarkers of cardiovascular and inflammatory disease of endometriosis. An important signaling mechanism through which circulating LDL and oxLDL act is the lectin-like oxidized LDL receptor (LOX-1). LOX-1 is a ubiquitously expressed scavenger receptor, stimulated by oxLDL, Ang II, and other inflammatory cytokines, and inhibited by estrogen. LOX-1 is the upstream signaling initiator of mechanisms including increased oxidant production, reduced nitric oxide (NO) metabolism, and impaired intracellular trafficking. Thus, LOX-1 signal transduction functionally results in pronounced endothelial dysfunction.

Inclusion criteria

• Healthy women between the ages of 18 and 45 years (Controls), taking oral contraceptive or with regular menses every 26-34 days
• Women between the ages of 18 and 45 years with endometriosis (diagnosis by prior laparoscopy by subject's own physician <5 years prior, and reported by the subject to the researchers)
• Tylenol if the subject has acute pain is allowed
• Contraceptive use is allowed

Exclusion criteria

• Use of nicotine-containing products (e.g. smoking, chewing tobacco, etc.)
• Diabetes (HbA1C 6.5%)
• BP>140/90
• Taking pharmacotherapy that could alter peripheral vascular control (e.g. insulin sensitizing, cardiovascular medications)
• Pregnancy
• Breastfeeding
• Taking illicit and/or recreational drugs
• Abnormal liver function
• Rash, skin disease, disorders of pigmentation, known skin allergies
• Diagnosed or suspected metabolic or cardiovascular disease
• Persistent unexplained elevations of serum transaminases
• Known allergy to latex or investigative substances (including salsalate or simvastatin)
• History of gastrointestinal bleeding