Sex differences in neuropathic pain intensity in diabetes

Introduction: Sex and gender play roles in the pain experience, such that pain is more frequent in women. Explanations for this observation range from factors related to biological sex to those related to psychosocial gender. Objectives: To explore neuropathic pain characteristics in females with diabetes with and without established polyneuropathy. Methods: We compared the presence and intensity of pain in males and females in 2 separate cohorts of patients with type II diabetes, with and without established diabetic polyneuropathy. Cohort #1 was recruited prospectively, while cohort #2 was studied retrospectively. Results: Cohort #1 of 223 patients with diabetes with a relatively broad spectrum of nerve injury, showed more frequent pain in females (68% versus 53% in males), a higher frequency of additional neuropathic symptoms, and evidence of milder nerve injury. Cohort #2 of 128 patients with established diabetic polyneuropathy, showed a similar frequency of pain and additional neuropathic symptoms in both sexes. In both cohorts, females reported greater pain intensity (7.9-8.5 versus 6.8-6.9 in males, on visual analog scale). Discussion: Though nerve injury and polyneuropathy are more common in males, females with diabetes report a higher frequency and intensity of pain despite milder polyneuropathy. Prospective epidemiological studies are required in order to confirm these findings in the community setting.