Association of Erectile Dysfunction With Neuropathic Pain, Disease Activity, and Functional Status in Male Patients With Axial Spondyloarthritis: A Cross-Sectional Observational Study

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease primarily affecting the axial skeleton and leading to progressive spinal stiffness, chronic pain, and functional impairment. The disease commonly affects young adults and may significantly impair physical, psychological, and social well-being.

Sexual dysfunction is increasingly recognized as an important yet underreported issue in patients with rheumatic diseases. Chronic pain, fatigue, reduced mobility, depression, altered body image, and systemic inflammation may all contribute to impaired sexual function in AS. In addition, neuropathic pain mechanisms may coexist with inflammatory pain and further affect quality of life and sexual performance.

Anti-tumor necrosis factor (anti-TNF) agents are effective in reducing disease activity and improving functional status and quality of life in AS. While improvement in physical symptoms may theoretically enhance sexual function, current evidence regarding the impact of anti-TNF therapy on sexual dysfunction remains limited and inconsistent.

This prospective observational study aims to compare sexual function, neuropathic pain, quality of life, and disease activity among three groups:

• Male AS patients receiving anti-TNF therapy,
• Male AS patients receiving only NSAIDs,
• Healthy male volunteers.

Sexual function will be assessed using the International Index of Erectile Function (IIEF). Neuropathic pain will be evaluated using the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS). Disease activity and functional status will be measured using BASDAI, BASFI, and BASMI indices. Quality of life will be assessed using the Ankylosing Spondylitis Quality of Life (ASQoL) questionnaire.

No experimental intervention will be performed, and no changes in ongoing treatments will occur during the study. The primary objective is to determine whether treatment modality and neuropathic pain are associated with sexual dysfunction in male patients with ankylosing spondylitis.

Inclusion criteria

Male participants aged 18 years or older

Diagnosis of ankylosing spondylitis according to accepted classification criteria (for patient groups)

Receiving anti-TNF therapy or NSAIDs for at least 3 months (for patient groups)

Ability to understand and complete study questionnaires

Provided written informed consent

For healthy control group:

Male volunteers aged 18 years or older

No history of inflammatory rheumatic disease

Exclusion criteria

Age under 18 years

Use of anti-TNF therapy or NSAIDs for less than 3 months

History of neurological disorders affecting sexual function

Known severe psychiatric illness

Use of medications known to significantly affect sexual function (e.g., antidepressants, antipsychotics)

Refusal to participate or incomplete questionnaire data