BONE-MINERAL DENSITY IN IMMIGRANTS FROM SOUTHERN CHINA TO DENMARK - ACROSS-SECTIONAL STUDY

Immigration from Japan to USA has been shown to increase bone mineral density (BMD) and body fat in women. The effects of immigration betwee n other geographical areas on bone mass and body composition are large ly unknown, especially in men, In the present study, we measured bone mass and body composition by dual energy X-ray absorptiometry (Hologic QDR-2000) in 73 healthy premenopausal women (age 35 +/- 8 years) and 69 men (age 40 +/- 12 years) who had immigrated from southern China to Denmark; 3 months to 36 years ago. The BMD measurements (Total BMD, t runk BMD and leg BMD) were related positively to years since immigrati on (YSI) (R(2) = 0.10-0.16, p < 0.05) in premenopausal women, but not in men. Fat distribution was related mainly to age in 2 both premenopa usal women and men (R(2) = 0.16-0.26, p < 0.05). For comparison, we in cluded 51 white, Danish premenopausal women (age 36 +/- 6 years). Chin ese premenopausal women with a YSI below or equal to 12 years (N = 38) had significantly lower total and regional RMD (trunk, legs, arms) (p < 0.05), while women with a YSI above 12 years (N = 35)had significant ly lower BMD in the legs only (p < 0.05) when compared to the Danish p remenopausal women. After correction for age, weight and height, Chine se premenopausal women with a YSI below or equal to 12 years still had significantly lower BMD in all regions (4-7%, p < 0.05), whereas no d ifferences in BMD were found between Chinese premenopausal women with a YSI above 12 years compared with Danish premenopausal women. In conc lusion, Chinese premenopausal women who immigrated to Denmark; more th an 12 years ago have a similar BMD to that of Danish premenopausal wom en. In the group who immigrated less than 12 years ago, a significantl y lower BMD was found.