Bone mineralization and body composition in turner syndrome

ABSTRACT

Females with Turner syndrome are at risk for decreased bone density from ovarian failure and possibly from haploin-sufficiency for bone-related X-chromosome genes. We studied the relation between bone density, anthropometry, body composition and chromosomal abnormalities in Turner syndrome. The study included 18 females with Turner syndrome. They were divided in two groups. Group A consisted of 12 cases with 45, X karyotype [classic Turner syndrome] and their mean age of 13.5 +/- 5.5 years. Group B included 6 cases with mosaic karyotype and their mean age of 16.3 +/- 4.2 years. Bone mineral density [BMD] was determined using dual energy X-ray absorptiometry scans [DEXA]. BMD was measured in the femoral neck [FN], lumber spine [LS], and forearm [FA]. Body composition was assessed using RJL body fat analyzer. Anthropometry was carried out for each case. Seventy-two percent of females investigated had osteope-nia. When BMD was expressed as z-scores [individual values compared to normal reference data matched for age and weight] for all cases at it was 0.587 +/- 0.10 at FN and was 0.630 +/- 0.17 at LS. In group A bone mineral density was decreased [osteope-nia] by 66.7% in FN, and 25% in LS. In group B bone mineral density was decreased by 66.7% in FN, and 50% in LS. When comparing females in group A with those of group B, there was no statistical difference in BMD at femur and spine. The ostopenia found in patients of group A and B was not related to type of X-chromosomal aberrations. Group A showed significant increase in TBW and Corinic index SDS as compared to group B. Body fat and lean percentages are similar in the two studied groups. Also, no correlation was found between BMD and body weight, body height, body fat or percentage body fat. Body composition changes seem to be more impressive in classic Turner patients, while BMD changes are similar in the two groups. Achieving optimal bone density is of critical importance for fracture prevention in TS