Measurement of bone mineral density in mother-daughter pairs for evaluating the family influence on bone mass acquisition: A GRIO survey

The relative influence of genetic and environmental determinants on bone ma ss is still unclear. Using an original multicentric mode of recruitment, ba sed on absorptiometry current practice, the hypothesis of a familial predis position to low bone mineral content was assessed. The study was based on d ual-energy X-ray absorptiometry (DXA) measurements of lumbar and femoral ne ck bone mineral density (BMD), using daughters of women with a low BMD (cas e mothers). These BMD values were compared with those of control daughters of women with a normal BMD. Case mothers (n = 72) aged 54.3 +/- 4.8 years w ere recruited on the basis of a questionnaire and a vertebral Z-score < - 2 SD. Their healthy daughters of more than 20 years (n = 77) aged 28.2 +/- 4 .9 years had their vertebral and femoral BMD Z-score determined. The contro l groups were composed of mothers aged 54.1 +/-4.7 years, paired by age +/- 2 years to the case mothers, and of their daughters of more than 20 years old, aged 27.7 +/- 5.8 years. For daughters, a significant difference was f ound between the mean vertebral Z-scores (-0.82 +/- 1.08 for cases and 0.01 +/- 1.14 for controls, p < 0.0001). The difference was in the same directi on but was not statistically significant for mean femoral Z-scores (-0.58 /- 1.15 for cases and -0.22 +/- 1.33 for controls, p < 0.073). These findin gs confirm the hypothesis of a familial predisposition to low BMD.