The epidemiology of bone loss in populations of Asian heritage is still poorly known. This study compared the skeletal status of a convenience sample of 396 Southeast Asian immigrants (172 Vietnamese, 171 Cambodians and 53 Laotians) residing in Rochester, Minnesota in 1997 with 684 white subjects previously recruited from an age-stratified random sample of community residents. Areal bone mineral density (BMD, g/cm2) and volumetric bone mineral apparent density (BMAD, g/cm3) were determined for lumbar spine and proximal femur using the Hologic QDR 2000 instrument for the white population and the QDR 4500 for Southeast Asian subjects; the machines were cross-calibrated from data on 20 volunteers. Lumbar spine BMD was 7% higher in white than Southeast Asian women (p < 0.001), and similar results were observed for the femoral neck; lumbar spine BMD was 12% higher in white than nonwhite men (p < 0.001). Race-specific discrepancies were reduced by calculating BMAD: for premenopausal women, lumbar spine and femoral neck differences between whites and Southeast Asians were eliminated; for postmenopausal women the lumbar spine differences persisted (p < 0.0001), while femoral neck BMAD was actually higher for Southeast Asians. There were no race-specific differences in femoral neck BMAD among men of any age (p = 0.312), but lumbar spine BMAD was less for younger (p = 0.042) but not older (p = 0.693) Southeast Asian men. There were differences among the Southeast Asian subgroups, but no clear pattern emerged. Predictors of lumbar spine BMAD in Southeast Asian women were age (p < 0.001), weight (p = 0.015) and gravidity (p = 0.037). Even after adjusting for bone size using BMAD, 32% and 9% of Southeast Asian women and men, respectively, would be considered to have osteoporosis at the femoral neck and 25% and 4%, respectively, at the lumbar spine. These findings indicate a need for culturally sensitive educational interventions for Southeast Asians and for physicians to pursue diagnosis and treatment to prevent osteoporosis-related disabilities in this population.

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To meet expectations for the participation of minority populations in research, we committed to enroll 140 minority subjects in addition to a random sample of Olmsted County, Minnesota residents (90% white) for a study of risk factors for age-related bone loss and fractures. We successfully enrolled 597 additional minority subjects but encountered specific problems with respect to identification of potential subjects, recruitment, obtaining informed consent, transportation to the study site, and collecting study data. These problems were resolved by observing the tenets of outreach to a diverse study population, namely (1) understand the target population; (2) establish explicit recruitment goals; (3) agree on research plans between study staff and minority communities; (4) continuously evaluate the recruitment process; and (5) maintain lines of communication. Success depended especially on the recruitment of cultural advisors from the different ethnic groups. These special efforts increased the recruitment cost substantially; the total expense of $122,000 for recruiting 550 Asian, Hispanic, and Somali subjects was almost 5-fold higher than the $26,000 required to recruit 699 mostly white study subjects from the population who were contacted by mail. Although it is not impossible to recruit minority subjects, investigators (and grant reviewers) should recognize that significant resources are required to gain access to ethnic communities for research. These results should contribute to more realistic budgets for recruiting minority subjects into clinical research studies. (J Bone Miner Res 2003;18:3-8)

The epidemiology of bone loss in populations of African heritage is still poorly known. We compared a convenience sample of 47 African-American (AA) residents of Rochester, Minnesota (32 women, 15 men) and 66 recent immigrants from Somalia (all women) with 684 white subjects (349 women, 335 men) previously recruited from an age-stratified random sample of community residents. Areal bone mineral density (BMD, g/cm(2)) and volumetric bone mineral apparent density (BMAD, g/cm(3)) were determined for lumbar spine and proximal femur using the Hologic QDR 2000 for white subjects and the QDR 4500 for the others; the instruments were cross-calibrated from data on 20 volunteers. Lumbar spine BMD was 18% higher in AA ( p<0.001) and 4% lower in Somali ( p = 0.147) than white women. Femoral neck BMD was 27% higher in AA women but also 11% greater in Somali women (both p<0.001) compared with whites. Lumbar spine BMD was 6% higher ( p = 0.132) and femoral neck BMD 21% higher ( p<0.001) in AA than white men. No Somali men were studied. After correcting for bone size differences, both lumbar spine ( p<0.01) and femoral neck BMAD ( p<0.001) were greater for Somali than white women, but the difference between Somali and AA women persisted. Lumbar spine and femoral neck BMAD values also remained significantly greater for AA women (both p<0.001) and men ( p<0.05; p<0.001) compared with whites. Weight was associated with BMAD at both skeletal sites in all groups, but adjustment for differences in weight did not reduce the discrepancy in BMAD values between Somali and AA women or between the latter group and whites. This heterogeneity among different ethnic groups of African heritage may provide an opportunity for research to better explain race-specific differences in bone metabolism.