Bone mineral density in women with ankylosing spondylitis.

Abstract

To determine bone mineral density (BMD) in premenopausal women with early ankylosing spondylitis (AS). Eighteen premenopausal women with AS without syndesmophytes, interapophysiary arthritis, and/or coxofemoral joint destruction were studied. BMD was analyzed at lumbar spine and femoral neck by dual energy x-ray absorptiometry (Hologic QDR 1000). Z scores and T scores related to the general Spanish population were recorded. Comparisons were performed using the Student t test. Pearson's correlation coefficients were used to study the correlation between BMD and the variables. Following the WHO classification, osteopenia was diagnosed in patients with T score between -1 and -2.5 and osteoporosis in those with T score < -2.5 at lumbar spine or femoral neck. The mean Z score for spine BMD was -0.19+/-0.7, and -0.03+/-0.85 for femoral neck BMD. There were no significant differences of Z score values compared to the general population. No significant correlation was found between BMD and disease duration, radiology sacroiliac score, and spine mobility. Densitometry showed osteopenia in 2 patients and osteoporosis in none. We found a slight reduction in BMD in premenopausal women with early AS, but the difference was not statistically significant. We discuss the factors related to its pathogenesis.