LOW BONE-MINERAL CONTENT IS COMMON BUT OSTEOPOROTIC FRACTURES ARE RARE IN ELDERLY RURAL GAMBIAN WOMEN

Osteoporosis is reported to be rare in Black Africa. The low fracture incidence among North American black women is explained by a high peak bone mass and preservation of bone mineral into old age, To assess wh ether this is the case among Black African women, we measured bone min eral content (BMC) and bone mineral density (BMD), using single- and d ual-photon absorptiometry, in 195 rural Gambian women aged over 44 yea rs and 391 white women of comparable age from three centers in the U.K . Measurements were made at the midshaft of the radius, distal radius, lumbar spine, and femoral neck The influence of height, weight, and n ationality on BMC and BMD was analyzed, BMC and BMD decreased,vith age at all sites, Age, decreasing weight, but not height were independent ly associated with lower BMC at all sites, BMC in Gambian women was lo wer than in British women by 31% at the lumbar spine and 16% at the mi dshaft of the radius, After adjustment for age, height, and weight, BM C among Gambian women remained 24% lower at the lumbar spine and 10% l ower at the radius, In women aged over 64 years, BMC at the lumbar spi ne was 42% lower and BMD was 31% lower in The Gambia (for all comparis ons, p < 0.005), We conclude that bone mineral mass is not preserved i n elderly Gambian women, However, minimal trauma fractures are rare in this population, These results challenge the concept of BMC as a prim ary determinant of fracture risk.