肝硬化病人下丘脑-垂体-甲状腺轴的功能变化及临床意义

目的 探讨不同级别肝硬化(LC)病人下丘脑-垂体-甲状腺轴的变化及临床意义.方法 91例LC病人按Child-Turcotte-Pugh(CTP)计分评级分为三组:LC-A组25例,LC-B组35例,LC-C组31例;另选27名健康人作为对照组.血清总三碘甲状腺原氨酸(TT3)、游离T3(FT3)、反T3(rT3)、总甲状腺素(TT4)、游离甲状腺素(FT4) 及促甲状腺激素(TSH) 均采用化学发光法检测,肝功能生化指标用RXL生化分析仪检测,凝血酶原时间(PT)用全自动血凝仪(血凝固法)检测.结果 从LC-A组到LC-C组随着肝硬化级别的增加,血清TT3和FT3水平逐渐降低,rT3渐次增高,TT4/rT3比值顺次下降,血清TT3分别与白蛋白、前白蛋白、载脂蛋白-A1和胆碱酯酶呈显著正相关(df=89,r值分别为0.568,0.260,0.317和0.599,P<0.05),与CTP分值及PT呈显著负相关(df=89,r值分别为-0.447和-0.297,P<0.01),TSH在各组间差异无统计学意义.共26例LC病人出现低T3综合征,LC-A组为0,LC-B组8例(22.9%),LC-C组18例(58.1%).经保肝、支持治疗1~2周后,随着肝功能好转低T3综合征也随之消失.心得安试验仅见FT4有所下降(16.84±3.16)vs (14.00±2.45) pmol·L-1,地塞米松试验未见甲状腺激素及TSH有明显变化.结论 肝硬化失代偿期随着肝功能的下降,发生低T3综合征的比例增多,与甲状腺激素转运蛋白合成功能减退、T4向T3转化减少有关,但随着病情好转低T3综合征便逐渐消失,无须补充甲状腺素.心得安或地塞米松试验对甲状腺功能未产生明显的影响,提示短期适量应用此类药物是安全的.

Functional changes and clinical significance of hypothalamic-pituitary-thyroid axis in liver cirrhotic patients

Objective To investigate the functional changes and clinical significance of hypothalamic-pituitary-thyroid axis in liver cirrhotic patients.Methods A total of 91 cases with HBV related liver cirrhosis (LC) were assigned into three groups:LC-A group (n=25),LC-B group (n=35) and LC-C group (n=31),according to Child-Turcotte-Pugh (CTP) score.In addition,27 healthy individuals served as control group.Serum thyroid hormones,including total triiodothyronine(TT3),free T3(FT3),revers T3(rT3),total thyroxine(TT4),free T4(FT4) and thyroid stimulating hormone(TSH),were measured with chemiluminescence method;the biochemical markers of liver function were detected by RXL automatic biochemical analyzer,and plasma prothrombin time (PT) was detected by blood cloting method.Results From LC-A to LC-C group,with the exacerbation of liver cirrhosis the serum levels of TT3,FT3 and TT4/rT3 ratio gradually decreased,while serum rT3 gradually increased.Serum TT3 concentrations were positively correlated with those of albumin (Alb,r=0.568,P<0.01),prealbumin (PA,r=0.260,P<0.05),apolipoprotein-A1 (Apo-A1,r=0.317,P<0.01) and cholinesterase (CHE,r=0.599,P<0.01) respectively.Conversely,serum TT3 concentrations were negatively correlated with CTP score and PT (r=-0.447 and-0.297 respectively,P<0.01,both).The serum values of TSH in each group were in the normal range.There were 26 cases with low T3 syndrome,8 of whom occurred in LC-B group (22.9%) and 18 in LC-C group (58.1%).After hepatoprotective and supportive therapy for 1-2 weeks,the liver function improved and the thyroid hormones returned to normal.The propranolol test revealed FT4 decrease(16.84±3.16) vs (14.00±2.45) pmol·L-1 only,and the dexamethasone test showed no obvious change in thyroid hormones and TSH levels.Conclusions The incidence of low T3 syndrome in decompensated LC patients was relatively high,which might result from impaired hepatic function,decreased synthesis of TH transporting proteins and reduced conversion of T4 to T3.However,this syndrome dissolved fastly as the liver function improved,thus the supplement of thyroid hormone seems not to be necessary.The propranolol and d dexamethasone tests showed no significant influence on thyroid function suggesting that short-term administration of these drugs might be safe.