Disease Burden in Axial Psoriatic Arthritis Differs Significantly by Gender

The burden of disease in patients with axial psoriatic arthritis (PsA) can differ significantly between genders, according to a new study published in Modern Rheumatology. While the authors found differences in disease expression among male and female patients with axial PsA, the cause of the differences remained unknown.

Researchers in Turkey analyzed the effect of gender on clinical findings, disease activity, functional status, and quality of life in 1018 patients with PsA. A total of 373 (150 male and 223 female) patients had axial involvement. In patients with axial involvement of PsA, the inflammation has progressed to the spine.

“The prevalence of axial involvement in PsA varies according to the duration of the disease,” the authors explained. “The incidence in the early stage of the disease varies between 5% and 28%, while this value increases up to 25-70% in the later stages of the disease.”

The cohort of patients was formed through participation of 25 different universities and research hospitals in Turkey. The researchers collected clinical, laboratory, and radiographic data. In the overall cohort, axial PsA was more common in women (21.9%) than men (14.7%). The cause for this discrepancy is unknown, according to the authors, but sex hormones and environmental factors may be important, they surmised.

While inflammatory back pain was more common in men, the difference was not statistically significant. Women were more likely than men to have peripheral arthritis, enthesitis, dactylitis, gluteal pain, and hip pain.

The visual analog scales for pain and fatigue, as well as the Health Assessment Questionnaire (HAQ), HAQ for Spondyloarthropathies, Functional Assessment of Chronic Illness Therapy, the Fibromyalgia Rapid Screening Tool, the Psoriatic Arthritis Quality of Life scale, the Bath Ankylosing Spondylitis Disease Activity Index, Disease Activity Score-28, and erythrocyte sedimentation rate were all worse for female patients compared with male patients.

Although male patients with axial PsA had statistically better quality of life parameters than female patients, they had worse Psoriasis Area Severity Index scores. Men with PsA without axial involvement also had better quality of life than women with PsA without axial involvement.

The female patients had higher rates of spondylitis in the first 10 years of their disease, while male patients had higher rates after 10 years:

• <1 year: 13.5% in females vs 12.7% in males
• 1 to <5 years: 39.0% in females vs 34.7% in males
• 5 to <10 years: 25.6% in females vs 20.7% in males
• 10 to <15 years: 12.1% in females vs 16.0% in males
• 15 to <20 years: 4.9% in females vs 6.0% in males
• 20+ years: 4.9% in females vs 10.0% in males

“We found that, at any given level of radiographic damage, women report worse functional outcomes,” the authors concluded. “All of these findings suggest that the phenotype of axial PsA differs between the genders, and this may influence the manner and timing of the diagnosis of PsA as well as the choice and timing for initiation of treatment.”

Reference

Nas K, Kiliç E, Tekeoğlu İ, et al. The effect of gender on disease activity and clinical characteristics in patients with axial psoriatic arthritis. Mod Rheumatol. Published online August 21, 2020. doi:10.1080/14397595.2020.1812870