Presence of chronic fatigue syndrome in endometriosis is associated with increased psychological stress and reduced cortisol levels

Abstract

OBJECTIVE: The etiology of endometriosis and its different manifestations are poorly understood. Endometriosis is associated with chronic fatigue syndrome (CFS). Stressful experiences during times of heightened neural plasticity are suggested to persistently program neural, endocrine and immune responses leading to pain syndromes such as CFS. In this study, we compared salivary cortisol at awakening, stressful life events, and history of trauma in women with endometriosis with or without a diagnosis of CFS. DESIGN: We analyzed data from a population-based surveillance study of CFS in Wichita, Kansas, which included a two-day clinical evaluation of subjects with CFS and age- and race-matched controls. MATERIALS AND METHODS: Endometriosis was self-reported as part of a gynecological questionnaire. CFS diagnosis was ascertained using the CDC 1994 criteria. Childhood and adult stress were assessed using self-report questionnaires. Saliva cortisol samples, collected during clinic day 1, were analyzed using radioimmunoassay. RESULTS: Of 116 women (n = 58 CFS, n = 58 controls) who attended the clinic, 30 self-reported endometriosis (19 with and 11 without CFS). Endometriosis alone was not associated with any stress-related measures. However, compared to women with endometriosis only, women with both endometriosis and CFS reported significantly higher childhood (emotional neglect, P < 0.05 and adult perceived stress (P < 0.01), more negatively evaluated events (P < 0.05), higher depressivity scores (P < 0.01), and slightly lower awakening cortisol concentrations (not sign.). CONCLUSIONS: Endometriosis alone was not associated with any stress-related measures. However, women with endometriosis and CFS had a higher rate of childhood and adult stress compared to women with a diagnosis of endometriosis only. Cortisol awakening response was marginally lower in women with endometriosis and CFS. The clinical relevance of these findings will be discussed.