A COMPARISON OF BONE-MINERAL DENSITY BETWEEN CAUCASIAN, ASIAN AND AFRO-CARIBBEAN WOMEN

1. We analysed the lumbar spine (L2-L4) and femoral neck bone mineral density results of Caucasian (n = 2232), Asian (Indian sub-continent) (n = 153) and Afro-Caribbean (n = 102) women referred for bone densito metry over a 30 month period. To assess the risk of osteoporosis, the results of Caucasian and Asian women were compared with those of a ref erence Caucasian population supplied by Lunar. 2. Subject characterist ics were similar in all three groups, other than expected ethnic diffe rences in stature and weight. We found that lumbar spine and femoral n eck bone mineral density in Caucasians was lower than in Afro-Caribbea ns, but higher than in Asians. Consistent with this, bone mineral dens ity was also lower in Asians as compared with the reference Caucasian population, both at the lumbar spine and femoral neck. As a consequenc e, a higher proportion of Asian women were classified as being at incr eased risk of osteoporosis than Caucasian women. 3. Since ethnic diffe rences in skeletal size might influence bone mineral density, we also obtained values for bone mineral content in Caucasian and Asian women that were corrected for projected skeletal area, and weight and years since menopause, using regression equations derived from the Caucasian study population. After this analysis, the difference in bone mineral content between Caucasians and Asians at the lumbar spine disappeared , while that at the femoral neck persisted. 4. We conclude that the as sessment of risk of osteoporosis in Asian women by comparing bone mine ral density with a reference Caucasian population may have limited val idity because of the influence of skeletal size on such measurements.