Ankylosing spondylitis in women and men: a case-control study.

During an ongoing survey of 161 patients with ankylosing spondylitis (AS), 25 females were identified and retrospectively studied in detail. For each, a case-control male subject with similar age of onset of illness (mean, 23.0 years for women, 22.2 years for men) and duration of followup (mean, 20.7 years for women, 17.0 years for men) was selected. The diagnosis of AS was delayed an average of 12.8 years for females and 10.3 years for males. Extraspinal arthropathy occurred in 18 women (72%) and 8 men (32%) (p less than 0.05). Cervical spine disease and shoulder arthritis each occurred in 10 women (40%) and 4 men (16%) (NS). Hip disease affected 10 females and 6 males (NS). Peripheral joint disease occurred in 12 women (48%) and 9 men (36%); the knees were most commonly involved. Recurrent uveitis affected 10 females and 1 male (p less than 0.01). Anemia was detected in 8 women and 2 men (p less than 0.05). Sixty percent of the women had relatives with spondylarthritis, compared to 35% of the men (p less than 0.05). This last finding suggests that, in addition to possible hormonal and anatomic influences on the expression of disease, there may be some sex-linked, genetic factors.