Gender Difference of Symptom Severity in Lumbar Spinal Stenosis: Role of Pain Sensitivity

Abstract

Background: Given that there are gender differences in pain perception, it is likely that there are differences in pain responses between men and women with lumbar spinal stenosis (LSS). Furthermore, these differences may lead to different degrees of impairment in both daily activities and quality of life between men and women. Objective: To elucidate the difference of LSS symptom severity between genders in relation to pain sensitivity. Study Design: Retrospective analysis of prospectively collected data. Methods: A total of 160 patients who had symptomatic degenerative lumbar spinal stenosis completed a series of questionnaires on their first visit in the outpatient clinic, including a pain sensitivity questionnaire (PSQ) (total PSQ and PSQ-minor), Oswestry Disability Index (ODI), visual analog scale (VAS) for back pain, and Short Form-36 (SF-36). Using magnetic resonance images, the degree of canal stenosis and disc degeneration were graded based on the method by Schizas and the Pfirrmann classification, respectively. Symptom severity, pain sensitivity, and radiologic findings were compared between men and women. In each gender group analysis, the correlation between pain sensitivity and symptom severity was analyzed. Results: After adjustment for age and the grade of disc degeneration, the pain sensitivity represented by total PSQ and PSQ-minor was significantly higher in women than in men. Moreover, there was a higher VAS for back pain/leg pain and ODI in women compared to men after adjustment for body mass index (BMI), age, and the grades of canal stenosis and disc degeneration. After additional adjustment for pain sensitivity including total PSQ and PSQminor, there was no difference in VAS for back pain/leg pain between genders. On the SF36 women demonstrated a lower quality of life than men in terms of Physical Function, Role Physical, Bodily Pain, General Health, and Physical Component Summary. Each gender group analysis showed that pain sensitivity was associated with symptom severity and disability caused by LSS in both women and men. Limitations: The present study did not evaluate psychological factors including catastrophizing and/or undiagnosed personal traits which possibly can influence the severity of symptoms from LSS. Conclusions: Women showed increased low back pain and leg pain due to degenerative LSS compared to men. The current study demonstrates that this difference in symptom severity may be partly mediated by pain sensitivity. Key words: Lumbar spinal stenosis, gender difference, visual analog scale, Oswestry Disability Index, Short Form-36, pain sensitivity