Evaluating Gender Differences in Egyptian Fibromyalgia Patients Using the 1990, 2011, and 2016 ACR Criteria.

Background: Fibromyalgia (FM) is a common rheumatic illness distinguished by chronic pain, fatigue, cognitive problems, and functional disability. However, the differences between men and women have not yet been comprehensively studied, especially after the development of the last 2016 American College of Rheumatology (ACR) criteria. The aim of this study was to evaluate the gender differences in symptom characteristics, cognitive dysfunction, and disease severity in Egyptian FM patients considering both the ACR 1990, 2011, and the last 2016 ACR diagnostic criteria.

Methods: This is a prospective cross-sectional study that was carried out on 352 patients with FM in the Rheumatology Department, Al-Azhar University Hospital in Egypt, in the period between January 1, 2020, and June 1, 2021. In addition to the number of tender points (TPC), data was collected on age, gender, body mass index (BMI), marital status, disease onset, duration, and diagnostic delay. The widespread pain index (WPI), the symptom severity scale (SSS), fatigue, cognitive dysfunction, sleep disturbance, awakening unrefreshed, headache, abdominal pain, and depression were evaluated and scored according to 2010 and 2016 ACR criteria. A visual analog scale (VAS) for pain, fatigue, stiffness, anxiety, and depression is included in the questionnaire. The total score ranges were produced using total score ranges ranging from 0 to 80 (excluding job items), with higher scores indicating a stronger negative effect and/or intensity of symptoms. The polysymptomatic distress scale (PDS) has been calculated by the summation of the SSS with the WPI. The Revised FM impact questionnaire (FIQR) has also been evaluated.

Results: The study shows that females have a significantly higher prevalence of fatigue, cognitive dysfunction, sleep disturbance, headache, and abdominal pain (p < 0.05). Also, females showed significantly higher scores than males regarding WPI, SSS, and mean TPC (p = 0.004, 0.027, and 0.001, respectively). While there was no difference regarding the FIQR (p=0.93), PDS was significantly higher in women (p= 0.001).

Conclusion: Female patients with FM had greater disease severity scores, symptomatology, and number of tender points. Whatever the criteria applied, the prevalence and intensity of the disease features are higher in females, which may underestimate the disease in male patients.