Background Osteoarthritis (OA) is a very frequent disease in postmenopausal women. The question whether high bone mineral density (BMD) plays a role in the development of this disease is under investigation.

Objectives Here we report the preliminary data of a study aimed at investigating the relationship between the BMD of healthy women and women with OA of the hip.

Methods Exclusion criteria included all diseases and drugs known to cause BMD loss. Till now 136 age matched women have entered the study: 46 with OA (mean age 65.76, SD 8.07) and 92 healthy individuals (mean age 65.60, SD 8.12). All subjects underwent Dual Energy X-ray Absorptiometry (DEXA-XR 36 Norland) measurements of the femoral neck, trochanter, Ward?s and the lumbar spine (L2-L4). Age, age of menopause, height and weight were also collected. Data were analysed using the Anova test to compare groups. The ability of selected parameters to discriminate the two groups of patients was tested by logistic regression.

Results Weight (p = 0.003) and femoral neck BMD (p = 0.045) were significantly higher in women with OA than in healthy women. None of the other variables were significantly different in the two groups. At the logistic regression both age corrected  weight (OR: 1.05; 95% CI: 1.01–1.09) and age corrected femoral neck BMD (OR: 1.01; 95% CI: 1.00–1.03) were able to significantly discriminate the two groups of women. Both variables correctly classified 13.04% of OA while 93.48% of healthy women were correctly classified by the variable weight and 97.83% the femoral neck BMD.

Conclusion Our data suggest that the body weight and femoral neck BMD are the main risk factors for OA of the hip. The fact that at the trochanter and at the Ward?s (where BMD measurement does not discriminate between the two groups) the cortical component of bone is lower than at the femoral neck should indicate that high cortical bone density is a marker of OA.