IGF-Ⅱ及CT含量对正常人骨代谢的影响

Effect of Changes of Serum IGF-Ⅱ and CT Contents on BoneMetabolism in Healthy Subjects

目的:了解不同年龄不同性别正常人胰岛素样生长因子-Ⅱ(IGF-Ⅱ)及降钙素(CT)含量变化对 骨代谢的影响。方法:选择180例正常人按不同年龄不同性别分为5组;进行IGF-Ⅱ和CT血清含量的测定, 均采用放射免疫分析法。结果:正常人随年龄的增加,IGF-Ⅱ及CT浓度逐步下降,其中IGF-Ⅱ血清含量(27 ～39)岁组与(60～69)岁组和70岁以上组比较P<0.05～P<0.01;(40～49)岁组与70岁以上组比较P< 0.01;(50～59)岁组与70岁以上组比较P<0.01。CT血清含量(27～39)岁组与50岁以上各组比较P<0.05 ～P<0.01间;(40～49)岁组与50岁以上各组比较P<0.01。不同性别间的比较在50岁以上女性IGF-Ⅱ和 CT含量略低于男性,但无统计学差异(P>0.05)。结论:正常人随着增龄IGF-Ⅱ浓度逐步降低,对骨骼细胞 的增殖和调控能力下降,抑制性IGF结合蛋白增加;同时,CT浓度的下降不能抑制破骨细胞介导的骨质吸收; 而老年女性IGF-Ⅱ及CT含量低于男性与雌激素水平降低可能有关。因此,老年性骨质疏松症与IGF-Ⅱ及 CT含量的变化有关,它们不仅参与了骨代谢而且是骨质疏松疾病发生的启动因子。

Objective To explore the effect of changes of serum insulinlike growth factor Ⅱ (IGF-Ⅱ) and calcitonin (CT) on bone metabolism in both male and female halthy subjects of different age groups. Methods Serum IGF-Ⅱ and CT contents were determined with RIA in 180 healthy subjects of both sexes in 5 age groups (27~39, 40~49, 50~59, 60~69 and over 70). Results The serum contents of IGF-Ⅱ and CT decreased gradually as the age increased. The IGF-Ⅱ contents in subjects above 70 were significantly lower than those in all other subjects (P<0.01); the values in subjects of the age group 27~39 were also significantly higher than those in the 60~69 group (P<0.05). Again, the serum CT contents in subjects over 50 were significantly lower than those in subjects below 50 (P<0.05, P<0.01). There were little differences among the levels in both sexes, with the exception of a slight but not significant lower value in the females above 50. Conclusion In older subjects, the decreased contents of serum IGF-Ⅱ would exert less modulation on osteoblastic activity while the decreased contents of CT would exert less inhibition on osteoclytic activity. The contents in older females were even lower due to the decreased estrogen level. Combination of these two factors would lead to the initiation and development of osteoporosis.