Gender characterization on the clinical characteristics and life quality of patients with ankylosing spondylitis

Objective To investigate the gender-attributable differences in clinical characteristics and life quality of ankylosing spondylitis (AS) patients. Methods A total of 522 AS patients (80 females and 442 males) were collected from the Department of Rheumatology, Chinese PLA General Hospital from August 2013 to September 2015. A comparison was conducted in terms of age at onset, disease course, family history, HLA-B27, clinical manifestations, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). The disease activity was assessed by the bath ankylosing spondylitis disease activity index (BASDAI) and AS disease activity score (ASDAS), physical function by the bath ankylosing spondylitis functional index (BASFI), spinal mobility by the bath ankylosing spondylitis metrology index (BASMI) and quality of life (QoL) by the Short Form-36 between male and female patients. Results Compared with male patients, female patients were older at disease onset (24.3±9.2 vs 20.5±7.5, P< 0.001), and had higher rates of peripheral articular involvement (55.6% vs 40.5%, P< 0.05), and a lower mental health score(54.2±15.4 vs 58.2±16.9, P< 0.05). But no significant gender-attributable difference was observed in other clinical parameters like low back pain, patients' global assessment scores, enthesitis, BASDAI, BASFI and ASDAS. In age< 40 years old group, female patients had lower BASMI scores (0.4±0.9 vs 1.0±1.5, P< 0.05), lower ASDAS scores (2.5±1.3 vs 2.7±1.2, P< 0.05) and lower mental health scores (54.8±14.8 vs 58.5±17.0, P< 0.05) than male. In the age ≥ 40 years old group, female had lower physical functioning (45.6±4.9 vs 75.0±23.9, P< 0.05) and bodily pain scores (42.9±24.1 vs 59.4±22.0, P< 0.05) in SF-36 than man. Female patients with positive HLA-B27 had lower mental health and bodily pain scores (48.6±25.1 vs 55.3±23.2, P< 0.05; 53.0±14.5 vs 58.1±17.1, P< 0.05), and female patients in highly active disease stage had lower bodily pain score than male patients (29.7±16.3 vs 38.9±18.9, P< 0.05). There was a significant improvement in ASDAS scores in female patients compared with male (1.3±1.7 vs 0.9±1.0, P=0.044). Conclusion AS more likely occurs in older age, had higher rates of peripheral articular involvement, and results in poor QoL in female patients than in male, especially in mental health domain. Moreover, significant impairment of spinal mobility are found in male AS patients.No gender-attributable differences in disease activity or physical function are found between male and female patient, which indicating that female disease should be paid the same attention on as male patients in clinical diagnosis and treatment.