AXIAL AND HIP BONE-MINERAL DENSITY AND RADIOGRAPHIC CHANGES OF OSTEOARTHRITIS OF THE KNEE - DATA FROM THE BALTIMORE LONGITUDINAL-STUDY OF AGING

Objective, To examine the relationship between axial and hip bone mine ral density (BMD) and radiographic changes of knee osteoarthritis (OA) . Methods. BMD of the lumbar spine and/or right hip was measured, usin g dual photon absorptiometry, in 402 men and 247 women in the Baltimor e Longitudinal Study of Aging who had bilateral standing knee radiogra phs taken between 1984 and 1991. Radiographs were read for features of OA using Kellgren-Lawrence and reliable individual feature scales. Th e relationship between BMD and radiographic changes of OA was examined using multiple linear regression adjusting for age, body mass index, and smoking. Additional analyses with adjustment for menopausal status and estrogen replacement therapy were performed in a subset of women. Results. Adjusted mean lumbar spine BMD was higher in subjects with k nee osteophytes in both sexes: 1.23 +/- 0.02 vs 1.18 +/- 0.01 g/cm(2) (p = 0.02) in men, and 1.12 +/- 0.02 vs 1.08 +/- 0.01 g/cm(2) (p = 0.0 7) in women. There were no differences in levels of adjusted hip BMD b y presence of any radiographic features of OA in either men or women. Conclusion, These results show that both men and women with radiograph ic changes of knee OA, specifically osteophytosis, have higher levels of adjusted spine but not hip BMD.