Chapter 21 Chapter 20 — 內分泌動態測試對照表

📅 最後更新：2026-05-01（v0.1 — 兩位 fellow camp 老師均強調「Endocrine dynamic tests 建議背熟」）

葉老師：「Endocrine dynamic tests 建議背熟」

21.1 20.1 🎯 fellow camp 老師強調的考點

葉老師 / 鄭老師強調點	標籤	為什麼考
HDDST（高劑量 dex）vs 1mg DST	筆試 + 口試	Cushing 鑑別
CRH test	筆試	Cushing’s disease vs Ectopic ACTH
OGTT for GH（acromegaly）	筆試	<1 / <0.4 切點
ITT (Insulin Tolerance Test)	筆試	GH + Cortisol gold standard
Synacthen / Cosyntropin (ACTH stim)	筆試	AI 鑑別
Salt loading + Saline infusion (PA confirmation)	筆試
Captopril challenge (PA confirmation)	筆試
Posture test (PA subtype)	筆試
Glucagon stim test	筆試	GH + Cortisol（ITT 不能用時）
GnRH stim test (precocious puberty)	筆試	Central vs peripheral
Water deprivation + DDAVP (DI)	筆試
Copeptin（DI 新工具）	筆試	Williams 15 update
TRH stim	筆試	Central vs primary hypoT
72hr fast (Insulinoma)	筆試	Hypoglycemia gold standard

21.2 20.2 📚 Pituitary / Adrenal Axis Tests

21.2.1 20.2.1 1mg Overnight Dexamethasone Suppression Test (1mg DST)

篩 Cushing’s syndrome

晚 11pm: 給 dex 1 mg PO
8 am:    抽 cortisol
判讀:    cortisol >1.8 μg/dL → fail (suspicious for Cushing)

干擾：CYP3A4 inducer（phenobarbital, phenytoin, rifampin → false positive）

21.2.2 20.2.2 24hr Urine Free Cortisol (UFC)

確認 Cushing’s syndrome

• ≥3× ULN → Cushing
• 至少 2 次 + creatinine 校正

21.2.3 20.2.3 Late-night Salivary Cortisol

• 兩次以上升高 → Cushing
• 24 hr cortisol rhythm 失調

21.2.4 20.2.4 High-Dose Dexamethasone Suppression Test (HDDST)

Cushing 鑑別 — Cushing’s disease vs Ectopic ACTH

方案 A (overnight): 11pm 給 dex 8 mg → 8am cortisol
方案 B (48-hr):     dex 2 mg q6h × 48 hr → 8am cortisol after last dose

判讀:
  Cortisol 抑制 >50% baseline → Cushing's disease
  Cortisol 抑制 <50%           → Ectopic ACTH

21.2.5 20.2.5 CRH Stimulation Test

Cushing 鑑別

Baseline ACTH + cortisol
給 ovine CRH 1 μg/kg IV
30, 45, 60 min: 抽 ACTH + cortisol

判讀:
  ACTH 升 >35% 或 cortisol 升 >20% → Cushing's disease
  No response                       → Ectopic ACTH

21.2.6 20.2.6 Inferior Petrosal Sinus Sampling (IPSS)

Cushing’s disease 確認 + 定位 — Gold standard

雙側 IPS catheterization + 周邊靜脈
抽 ACTH (baseline + post-CRH)
計算 Center:Peripheral ratio:
  Baseline ≥2  或 post-CRH ≥3 → Cushing's disease
  右/左 ≥1.4   → 微腺瘤側 (但定位敏感度有限)

21.2.7 20.2.7 ACTH Stimulation Test (Synacthen / Cosyntropin)

AI 鑑別

Baseline cortisol + ACTH
給 cosyntropin 250 μg IV / IM
30, 60 min cortisol

判讀:
  Peak ≥18-20 μg/dL → 排除 Adrenal Insufficiency
  Peak <18 μg/dL    → AI

注意:
  急性 2° AI (<3 個月)    cosyntropin 可能仍正常 (adrenal 還沒萎縮)
                           → 需 ITT 或 Metyrapone
  Low-dose ACTH (1 μg)   敏感度更高（但 lab 困難）

21.2.8 20.2.8 Insulin Tolerance Test (ITT) — Gold Standard

評估 GH + Cortisol axis 同步

Insulin 0.05-0.15 U/kg IV
監測：glucose, GH, cortisol
目標 hypoglycemia: glucose <40 mg/dL

判讀:
  Adult GH deficiency:  peak GH <3 ng/mL
  Cortisol deficiency:  peak cortisol <18 μg/dL

禁忌:
  IHD / 癲癇 / 老年 / cortisol 已知 severely low

21.2.9 20.2.9 Glucagon Stimulation Test

ITT 替代（IHD / 癲癇）

Glucagon 1 mg (≥90 kg: 1.5 mg) IM/SC
監測 glucose, GH, cortisol q30min × 4 hr

判讀:
  GH peak <3 ng/mL → GH deficiency
  Cortisol <18 μg/dL → AI

21.2.10 20.2.10 Macimorelin Test

較新；GH-secretagogue receptor agonist；FDA 2017 approved

口服 0.5 mg/kg
30, 45, 60, 90 min GH
GH peak <2.8 ng/mL → Adult GH deficiency

21.2.11 20.2.11 OGTT for GH（Acromegaly Confirmation）

75g glucose PO
0, 30, 60, 90, 120 min: glucose + GH

判讀:
  Standard assay: nadir GH >1 μg/L → 仍有 acromegaly 活動
  Ultrasensitive: nadir GH >0.4 μg/L → 仍有 acromegaly

21.2.12 20.2.12 Metyrapone Test

ACTH reserve（替代 ITT）

Metyrapone 30 mg/kg PO 半夜 → 抑制 11β-hydroxylase → cortisol ↓ → ACTH ↑
8am: 抽 11-deoxycortisol + ACTH

判讀:
  11-deoxycortisol <7 μg/dL → 2° AI
  ACTH <100 pg/mL → 2° AI

21.3 20.3 📚 Aldosterone / PA Tests

21.3.1 20.3.1 Aldosterone-Renin Ratio (ARR) — 篩檢

晨抽 (≥30 min standing):
  Plasma aldosterone (PAC, ng/dL) / Plasma renin activity (PRA, ng/mL/hr)

判讀:
  ARR ≥20-30（依 lab）+ aldosterone >10 ng/dL → 進確認

干擾藥停 4-6 週:
  停: MRA (8 wk) / β-block / ACEi / ARB / 利尿劑
  替代藥（葉老師標）:
    Non-DHP CCB (Verapamil, Diltiazem)
    α1-blocker (Doxazosin)
    Vasodilator (Hydralazine)

21.3.2 20.3.2 PA Confirmation — 4 選 1

21.3.2.1 Saline Infusion Test

2 L NS over 4 hr (lying)
判讀: aldosterone <5 ng/dL → 排除 PA
       aldosterone >10 ng/dL → 確認 PA
       5-10 ng/dL → equivocal

21.3.2.2 Oral Salt Loading

高鈉飲食 200 mEq/d × 3 天
24-hr urine aldosterone + Na excretion
判讀: urine aldosterone >12 μg + urine Na >200 mEq → PA

21.3.2.3 Fludrocortisone Suppression

Fludrocortisone 0.1 mg q6h × 4 d + KCl + NaCl
Day 4 morning: aldosterone + renin
判讀: aldosterone >6 ng/dL → PA

21.3.2.4 Captopril Challenge

口服 Captopril 25-50 mg
60-90 min: aldosterone + renin
判讀: aldosterone 抑制 <30% → PA

21.3.3 20.3.3 Adrenal Vein Sampling (AVS)

確認後 + 考慮手術 → AVS 鑑別 unilateral vs bilateral

雙側腎上腺靜脈 + 周邊靜脈
抽 cortisol + aldosterone (baseline ± post-cosyntropin)

Selectivity index (SI) = adrenal vein cortisol / IVC cortisol > 5
Lateralization index (LI) = (高側 A/C) / (低側 A/C)
  LI >4 → unilateral
  LI <3 → bilateral

21.3.4 20.3.4 Posture Test

已較少用；FH-1 (GRA) 鑑別

8am 平躺 → 抽
站立 4 hr → 抽

判讀:
  Aldosterone 下降 → GRA
  Aldosterone 上升 → 一般 PA

21.4 20.4 📚 Pheochromocytoma Tests

21.4.1 20.4.1 Plasma Free Metanephrines

24-hr 卧位後晨抽
Metanephrine + Normetanephrine

判讀: >3-4× ULN → Pheo high probability
干擾: TCA / labetalol / acetaminophen / caffeine 停 2 週

21.4.2 20.4.2 24hr Urinary Fractionated Metanephrines

次選（敏感度高、特異度較弱）

21.4.3 20.4.3 Clonidine Suppression Test

已較少用；emergency Pheo 鑑別

21.5 20.5 📚 Posterior Pituitary — DI / SIADH

21.5.1 20.5.1 Water Deprivation Test (WDT)

禁水（依嚴重度 4-12 hr）
監測 urine osm + serum osm + 體重

階段 1 — 禁水至 serum osm >295：
  Urine osm >700 → 排除 DI
  Urine osm <300 → DI

階段 2 — DDAVP 0.03 μg/kg SC:
  Urine osm 上升 >50% → Central DI
  Urine osm 上升 <50% → Nephrogenic DI

21.5.2 20.5.2 Copeptin（Williams 15 update）

基線 + Hypertonic saline (3% NaCl) infusion
serum osm 達 295 → 抽 copeptin

判讀:
  Copeptin <4.9 pmol/L  → Central DI
  Copeptin >4.9 pmol/L  → 排除 Central DI

替代法 — Arginine + Copeptin:
  Arginine infusion + 60 min copeptin
  <3.5 pmol/L → Central DI
  較安全（不需嚴重高鈉）

21.5.3 20.5.3 SIADH 確認

• Hyponatremia + low serum osm + concentrated urine + euvolemia + 排除 hypothyroid + AI

21.6 20.6 📚 Thyroid Tests

21.6.1 20.6.1 TRH Stimulation Test

Central hypoT 鑑別（已較少用）

TRH 200-500 μg IV
30, 60 min TSH

判讀:
  TSH >5 mIU/L 升 → Primary hypoT (TSH 已高 + 過度反應)
  TSH 反應遲鈍 → Central (3°)
  TSH 反應差 / 不下降 → TSH-oma

21.6.2 20.6.2 24-hr RAI Uptake (RAIU)

口服 I-131 → 24 hr 後計算 thyroid uptake %

判讀:
  10-30% = 正常
  >30% (high uptake) → Graves / 多結節 / 單結節
  <10% (low uptake) → Subacute / silent / postpartum thyroiditis / 外因性 LT4 / Iodide excess

21.7 20.7 📚 Hypoglycemia Tests

21.7.1 20.7.1 72-hr Fasting Test — Insulinoma Gold Standard

監測 glucose q4-6h
出現低血糖（<55 mg/dL）+ 症狀（Whipple's triad）→ 抽:

  Glucose / Insulin / C-peptide / Proinsulin / β-OH-B / SU screen / Anti-insulin Ab

判讀（已於 Ch 7）:
  Glu <55 + Insulin ≥3 + C-pep ≥0.6 + Proinsulin ≥5 + β-OH-B ≤2.7 + SU(-) → Insulinoma

21.7.2 20.7.2 Selective Pancreatic Arterial Calcium Stimulation Test (SACST)

NIPHS 鑑別 + 定位

Catheter 進胰臟分區動脈 (gastroduodenal / SMA / splenic)
注 Ca + 採肝靜脈 insulin
某分區 insulin 急升 → 該分區 β cell 過度活躍

21.7.3 20.7.3 Mixed Meal Tolerance Test (MMTT)

評估 β cell residual function（T1DM / Honeymoon / MODY）

21.8 20.8 📚 Reproductive Tests

21.8.1 20.8.1 GnRH Stimulation Test

中樞 vs 末梢 precocious puberty

GnRH (Leuprolide) 20 μg/kg SC
60 min: LH

判讀:
  Pubertal LH response (>5 mIU/L) → Central PP
  No response                      → Peripheral PP

21.8.2 20.8.2 hCG Stimulation Test

男性 hypogonadism — Leydig cell function

hCG 5000 IU IM × 3 d
72 hr post: testosterone

正常: testosterone 至少 doubling
無反應: Primary testicular failure

21.8.3 20.8.3 Clomiphene Stimulation Test

男性 hypogonadism — central pituitary function

Clomiphene 100 mg/d × 7 d
LH + FSH 升高 → central pituitary 功能完整

21.9 20.9 📚 Calcium-Phosphate Tests

21.9.1 20.9.1 24-hr Urine Calcium

PHPT vs FHH 鑑別

結果	鑑別
24-hr urine Ca >300 mg	PHPT
24-hr urine Ca <100 mg + Ca/Cr clearance ratio <0.01	FHH (Familial Hypocalciuric Hypercalcemia, CaSR mutation)

21.9.2 20.9.2 Intra-operative PTH (ioPTH)

PHPT 手術成功確認

• 切除後 10 min PTH 下降 >50% + 落入正常範圍 = 成功

21.10 20.10 📚 必背速查表（口試最後 30 分鐘背）

Test	結果	鑑別
1mg DST cortisol >1.8	Cushing 篩檢 +
24h UFC ≥3× ULN	Cushing 確認
HDDST 抑制 >50%	Cushing’s disease
HDDST 不抑制 + CRH 無反應	Ectopic ACTH
ACTH stim peak <18	AI
ITT GH peak <3	Adult GH deficiency
OGTT GH nadir >1 (std)	Acromegaly 活動
ARR >20-30	PA 篩檢 +
Saline aldosterone <5	排除 PA
AVS LI >4	Unilateral PA
Plasma metanephrine >3× ULN	Pheo high probability
WDT urine osm 上升 >50% post DDAVP	Central DI
Copeptin <4.9 (post hypertonic)	Central DI
GnRH stim LH >5	Central PP
24h urine Ca <100 + Ca/Cr <0.01	FHH
ioPTH ↓ >50% within 10 min	PHPT 手術成功
72hr fast Glu <55 + Ins ≥3 + C-pep ≥0.6 + SU(-)	Insulinoma

21.11 20.11 💎 Pearls + Cross-ref

21.11.1 Pearls

1. HDDST + CRH + IPSS = Cushing 鑑別三關鍵
2. OGTT GH < 1 (standard) / < 0.4 (ultrasensitive) = Acromegaly disease control
3. ITT GH peak < 3 / Cortisol < 18 = AI / GH deficiency 雙標準
4. ACTH stim 急性 2° AI 可能 false negative → ITT
5. PA 確認 4 選 1：Saline / Oral salt / Fludrocortisone / Captopril
6. AVS LI >4 unilateral / <3 bilateral
7. Plasma metanephrine 比 24h urine 敏感
8. WDT + DDAVP = DI 鑑別；Copeptin = 新一代
9. GnRH stim LH >5 = central PP；FSH stim = peripheral
10. 72hr fast = Insulinoma gold standard
11. ioPTH ↓ >50% = PHPT 手術成功
12. 24h urine Ca + Ca/Cr clearance ratio = PHPT vs FHH 鑑別

21.11.2 Cross-ref

• 本書相關：Ch 14 Pituitary（GH stim）、Ch 15 Adrenal（HDDST/CRH/IPSS/ACTH stim/CAH）、Ch 16 PA（ARR/Saline/AVS）/ Pheo（metanephrines）、Ch 7 Hypoglycemia（72hr fast/SACST）、Ch 17 PHPT（ioPTH/24h urine Ca）、Ch 19 性腺（GnRH stim）