A follow-up study for planning preventive procedures of osteoporosis based on genetic and lifestyle risk assessment

为了建立预防骨质疏松症的有效方法，我们评估了与骨代谢相关的几个基因多态性的影响，以及各种生活方式因素对腰椎骨密度及其在随访期间变化的影响。结果表明：(1)维生素D受体基因型对基线骨密度有显著影响，在调整了年龄、绝经状态、身高和体重的混杂效应后。(2)雌激素受体基因型对基线骨密度的影响相对较小，但与维生素D受体基因型的影响无关。(3)利用单链构象多态性技术在骨钙素基因启动子区发现了一个新的多态性。我们建立了一个程序，以检测该基因的这个位置的限制性片段长度多态性使用Hind III酶。这种多态性的突变等位基因的纯合子被认为对骨质减少的发生具有显著更大的风险。(4)这些多态性在基线时对骨密度有显著影响，而在随访期间对骨密度变化无显著影响。(5)增加膳食钙摄入量和增加躯干肌肉力量对增加骨密度有显著影响，而吸烟习惯对绝经后妇女骨密度的影响逐渐减弱。遗传因素可能在获得峰值骨量方面发挥重要作用，但在决定绝经后骨质流失的量方面不起作用。考虑到遗传风险的骨质疏松症预防措施可能适用于年轻人。

To establish effective procedures for the prevention of osteoporosis, we evaluated the effects of polymorphisms of several genes relating to bone metabolism and the effects of various lifestyle factors on bone mineral density of the lumbar spine and on its change during the follow-up period. The results obtained were as follows :(1)Vitamin D receptor genotype showed a significant effect on the bone mineral density at baseline after the adjustment of the confounding effects of age, menopausal status, height and weight.(2)Estrogen receptor genotype had relatively smaller but still significant effect on the bone mineral density at baseline independently from the effect of vitamin D receptor genotype.(3)We found a novel polymorphism in the promoter region of the osteocalcin gene by single strand conformation polymorphism technique. We established a procedure to detect a restriction fragment length polymorphism of this site of the gene using a restriction enzyme Hind III.The homozygote of the mutant allele of this polymorphism was suggested to have a significantly greater risk for the development of osteopenia.(4)These polymorphism exhibited significant effects on bone mineral density at baseline while no significant effect was observed on the change in bone density during the follow-up.(5)Greater dietary calcium intake and greater muscle strength of the trunk had a significant effect in increasing bone density and smoking habits showed a decreasing effect in postmenopausal women.Genetic factors may play a great role in acquiring the peak bone mass but not in determining the amount of postmenopausal bone loss. Preventive procedures for osteoporosis allowing for the genetic risk might be applied on younger people.