VITAMIN-D-RECEPTOR ALLELES DO NOT PREDICT BONE-MINERAL DENSITY OR BONE LOSS IN DANISH PERIMENOPAUSAL WOMEN

A BsmI restriction enzyme polymorphism in the vitamin D receptor (VDR) gene has been reported to be associated with bone mineral density (BM D) and bone turnover. However, findings in other studies suggest the p resence of considerable interaction by race, body size, and environmen tal Factors. Therefore, we VDR BsmI genotyped 200 healthy perimenopaus al Danish white women (mean age 50.8 years, mean calcium intake 900 mg /day) in a comprehensive, longitudinal, community-based population stu dy. Bone loss was assessed by dual-energy X-ray absorptiometry (DXA) u sing cross-calibrated Hologic QDR-1000W and QDR-2000 densitometers, wi th a mean follow-up period of 4 years (range 1-5 years). Despite a dis tribution of genotypes similar to that of other white populations (28% bb, 49% Bb, 23% BB), VDR genotypes were not associated with lumbar or femoral baseline BMD, subsequent bone loss rates, or biochemical mark ers of bone metabolism (bone-specific alkaline phosphatase, urinary hy droxyproline, and serum osteocalcin), Controlling for body size, calci um intake, and serum levels of 25-hydroxyvitamin D-3 [25(OH)D-3] did n ot alter this finding. The possible existence of a threshold effect wa s subsequently investigated by restricting analysis to women with low serum 25(OH)D-3 levels or low calcium intake, VDR BsmI genotypes showe d no significant impact on bone density or bone loss in healthy Danish early postmenopausal women, even when allowance was made for calcium intake, serum 25(OH)D-3, and body size. (C) 1998 by Elsevier Science I nc. All rights reserved.