1、内分泌性高血压低血钾(一)库欣综合征,临床药师 张崇 襄阳市第一人民医院,Cushings Syndrome,1912年,Harvey Cushing发现了1例23岁的女性,表现为肥胖、多毛、闭经20年后, Harvey Cushing提出了由垂体功能异常导致肾上腺增生的“多腺体综合征”的概念随后的数十年里,人们陆续发现了肾上腺肿瘤可导致类似的表现1962年,发现异位ACTH综合征。随后“Cushings Syndrome”被用来描述一系列类似表现的总称,A:向心性肥胖、水牛背;B:满月脸;C:多毛、痤疮;D:向心性肥胖、满月脸;E和F:腹部青色条纹;G:先天性肾上腺皮质增生用过量地塞米松治疗
2、后;H:皮肤变薄,挫伤,A:股骨头坏死B:股骨头坏死C:脊柱塌陷D:肋骨骨折,Hirsutism:多毛症Psychiatric dysfunction:精神异常Backache:腰痛,Plethora:血液系统异常Bruising:挫伤Red-purple striae:紫红色条纹Ankle edema:踝关节水肿Pigmentation:色素沉积,Osteoporosis:骨质疏松Renal calculi:肾结石,1、水盐代谢失衡的发生机制(高血压低血钾):,2、Hypokalemic alkalosis (低血钾性碱中毒)is found in 10% to 15% of patient
3、s with Cushings disease but in more than 95% of patients with ectopic ACTH syndrome.,3、The functions of the pituitary-thyroid axis and the pituitary-gonadal axis are suppressed in patients with Cushings syndrome because of a direct effect of cortisolon TSH and gonadotropin secretion,4、Growth hormone
4、 secretion is reduced,1、ACTH依赖性占7080%,包括垂体肿瘤和异位ACTH综合征;ACTH非依赖性占2030%,主要为肾上腺肿瘤和肾上腺皮质增生2、异位ACTH综合征中肺癌占比超过50%,以小细胞肺癌为主,如何诊断?,1、血ACTH和皮质醇测定,2、24小时尿游离皮质醇(UFC)不受血液皮质醇结合球蛋白浓度的影响,敏感性大91%96%;需至少测定2次饮水过多(5L/d)、任何导致皮质醇增多的病理和生理状态下可出现假阳性中、重度肾功能不全(GFR60)可出现假阴性放免法受皮质醇代谢产物和外源性糖皮质激素影响;HPLC-串联质谱法受某些药物影响,如卡马西平和非诺贝特,3
5、、Low-Dose Overnight Dexamethasone Suppression Tests,原理:在正常人,超生理剂量的地塞米松可抑制ACTH和皮质醇的分泌;而在任何类型的库欣患者,均不能被抑制方法:午夜1112点口服地塞米松 1 mg,早8:00采血监测皮质醇浓度. A normal response is a plasma cortisol level of less than 140 nmol/L (5 g/dL) between 8 and 9 a.m. the following morning(敏感性91%,特异性95%)如果采用50 nmol/L 为介值,敏感性大于9
6、5%,单特异性只有80%左右地塞米松的吸收代谢率不同对结果有影响:CYP3A4诱导剂,苯巴比妥、卡马西平、利福平可导致假阳性;肝肾功能衰竭者地塞米松清除率降低可导致假阴性,检查前测清晨血皮质醇,然后给予地塞米松口服 ,0.5 mg every 6 hours for 48 hours.,然后再测Using a postdexamethasone plasma cortisol concentration of less than 50 nmol/L (2 g/dL) as the cutoff pointthis test is reported to have a 97% to 100% t
7、rue-positive rate and a false-positive rate of less than 1%.,经典方法:,如何诊断?,High-Dose Dexamethasone Suppression Test,2 mg dexamethasone every 6 hours for 48 hours and demonstrating a fall of greater than 50% in urinary 17-hydroxycorticosteroids(2mg,Q6H,48小时),In the modern test, the plasma or urinary fr
8、ee cortisol (or both) is measured at 0 and +48 hours, and a greater than 50% suppression of plasma cortisol from the basal value has been used to define a positive response(下降50%以上为被抑制),About 90% of patients with Cushings disease have a positive 48-hour test, compared with 10% of those with the ecto
9、pic ACTH syndrome,敏感性6080%,特异性8090%,CRH刺激试验中库欣和异位ACTH综合征的表现,生长抑制受体显像(SRS),生长抑制受体是位于细胞膜表现的G蛋白偶联受体,有5种亚型,分别为SSTR15。人工合成的生长抑素类似物,如奥曲肽,可与SSTR结合。异位分泌ACTH的肿瘤高表达SSTR2,给予放射性核素标记的奥曲肽后,可在体内显像。但敏感性较低,仅约49%。需用SPECT,价格较贵。,Medical Treatment of Cushings Syndrome,病例:,女,38岁,BMI 30.67,腰围92cm,臀围100cm,因“眼睑浮肿伴体重增加1年”入院,
10、血压160/105mmHg,甲功TSH 1.09uIU/ml,FT3 1.68pmol/L,FT4 0.68pmol/L;ACTH 1.4ng/L;垂体MRI未见明显异常。病程中无月经紊乱,无纳差乏力。体检无明显阳性体征。初步诊断:1、垂体前叶功能减退? 2、高血压,入院查:1、TC 6.05mmol/L,HbA1c 5.7%,2、IGF-1 393ng/ml (109-284),3、性激素八项+GH:GH 4.087ng/ml;泌乳素27.62ng/ml(3.34-26.72);硫酸脱氢表雄酮 9.76ug/dl(23-266)4、RAAS系统无明显异常5、肾上腺CT:左肾上腺多发占位,参考值:ACTH 0-46;皮质醇上午4.26-24.85,下午2.9-17.3,小剂量地塞米松(1mg)抑制试验,大剂量地塞米(8mg)松抑制试验,手术后复查,24小时尿皮质醇:230.58ug/24h,患者感乏力,予强的松10mg QD1,5mg QD5,口服后好转,出院诊断:非ACTH依赖性皮质醇增多症;左肾结石(病理:左侧肾上腺皮质腺瘤),手术后(mmHg),手术前(mmHg),