中青年甲状腺功能亢进患者骨密度特点

Characteristics of bone mineral density in young adult patients with hyperthyroidism

目的分析中青年甲状腺功能亢进(甲亢)患者骨密度特点及其与病程、病情严重程度的关系。方法使用双能X线骨密度仪分别测定340例中青年甲亢患者及160名年龄匹配的正常对照者的前臂、腰椎及股骨颈骨密度,用化学发光法测定甲亢患者游离三碘甲腺原氨酸(FT3)、游离甲状腺激素(FT4)及促甲状腺激素(TSH),用自动生化仪检测血清钙(Ca)、血清磷(P)、碱性磷酸酶(ALP),比较2组间骨密度及Ca、P、ALP的差异。根据国际临床骨密度学会(ISCD)和国际骨质疏松基金会(IOF)对中青年骨质疏松诊断的不同定义分别将甲亢患者分为骨量正常组(ON1)和骨质疏松组(OP1)、骨量正常组(ON2)、骨量减少组(OD2)、骨质疏松组(OP2),比较使用2种诊断方法得出的骨质疏松检出率,比较各组甲状腺激素(TH)及TSH的差异。结果与正常对照组相比,甲亢患者桡骨全部、腰椎L2-4及股骨颈骨密度均明显降低(均P<0.05)。根据ISCD定义得出的骨质疏松检出率为46.8%,根据IOF定义得出的骨质疏松检出率为27.1%,前臂较腰椎、股骨颈骨密度降低更明显。甲亢患者骨质疏松组较骨量正常组的FT3、FT4明显升高(P<0.05),TSH明显降低(P<0.05)。多元线性回归分析显示桡骨骨密度与FT4、Ca呈负相关,与TSH呈正相关。结论中青年甲亢患者骨质疏松患病率高,骨量丢失较明显的部位为桡骨,过量甲状腺激素及低TSH均可导致骨代谢紊乱。

Objective To investigate the effect of the course and condition of hyperthyroidism on the change of bone mineral density （ BMD） in young adult patients .Methods BMDs at forearm , lumbar vertebrae , and femoral neck were measured using dual-energy X-rays absorptiometry （DEXA） in young adult patients （n=340） and normal subjects （n=60）.Free triiodothyronine （FT3）, free thyroxine （FT4）, and thyroid stimulating hormone （TSH） levels were measured using chemiluminescence method . Alkaline phosphatase （ ALP ） , calcium （ Ca ） , phosphorus （ P ） were measured using automatic biochemical analyzer .ALP, Ca, P, BMD at forearm, lumbar vertebrae and femoral neck were compared between patients amd and normal subjects .According to the different definitions of osteoporosis in the young from International Society for Clinical Densitometry （ISCD） and International Osteoporosis Foundation （IOF）, patients were divided into normal group1 （ON1） and osteoporosis group1 （OP1）, normal group2 （ON2）, Osteopenia group2 （OD2） and osteoporosis group2 （OP2）.Compared the incidence of osteoporosis in two different diagnostic criteria .Be-sides, thyroid hormone （TH） and TSH were compared among all groups of patients .Results The BMD at forearm （to-tal radius）, lumbar vertebrae 2-4, and femoral neck in the patients were significantly lower than those of normal subjects （ P＆lt;0.05 ） .Ca, ALP in the patients were significantly higher than those of normal subjects （ P＆lt;0.05 ） .Osteoporosis was found in 46.8%of patients according to definition of ISCD , and in 27.1%of patients according to definition of IOF . Among the three measurement sites , forearm had the highest rate of osteoporosis .. The multiple regression analysis showed that there was an independent negative correlation between BMD of forearm and FT 4, Ca, and an independent positive correlation between BMD of forearm and TSH .Conclusion The rate of osteoporosis in patients with hyperthy-roidism is high and the forearm bone is more obrious .High level of FT3 and FT4 and low level of TSH can cause abnormal bone metabolism .