17.3 16.3 📚 Primary Aldosteronism (PA)
17.3.2 16.3.2 篩檢適應症(Endocrine Society)
- HTN + Hypokalemia (spontaneous or diuretic-induced)
- Resistant HTN (≥3 藥)
- Adrenal incidentaloma + HTN
- HTN < 30 歲
- 家族史 PA / 早發 stroke
17.3.3 16.3.3 篩檢
- Aldosterone-Renin Ratio (ARR):通常 cutoff ≥20-30 ng/dL per ng/mL/hr(依 lab)
- 干擾:MRA / β-block / ACEi / ARB / 利尿劑 → 應停 4-6 週
- 替代藥(葉老師標):non-DHP CCB (Verapamil, Diltiazem) / α1-blocker (Doxazosin) / Vasodilator (Hydralazine)
17.3.4 16.3.4 確認測試(4 選 1)
| Test | 內容 |
|---|---|
| Saline infusion | 2L NS 4 hr → aldosterone ↓ <5 ng/dL = 排除 |
| Oral salt loading | 高鈉飲食 3 天 → 24 hr 尿 aldosterone ↑ → 確認 |
| Fludrocortisone suppression | Fludrocortisone × 4 d → aldosterone 不抑制 |
| Captopril challenge | Captopril → aldosterone 不抑制 |
17.3.5 16.3.5 亞型鑑別 — Adrenal Vein Sampling (AVS)
確認 PA 後,如果考慮手術 + <35 歲 + 影像清楚 → 可不做 AVS;否則 AVS 鑑別 unilateral vs bilateral
- AVS lateralization index (LI) >4 = unilateral
- LI <3 = bilateral
17.3.6 16.3.6 Familial Forms (FH-1 ~ FH-4) — 葉老師大表
| 類型 | 基因 / 機轉 | 臨床特徵 | 治療 |
|---|---|---|---|
| FH-1 | Hybrid CYP11B1/B2 (chimeric gene) | 兒童或年輕人 HTN / 家族史 / 出血性 stroke | Dexamethasone, MRA |
| FH-2 | CLCN2 | More common than type I FH but <6% all PA | MRA |
| FH-3 | KCNJ5 | More than type I but less than 6% in all PA | MRA |
| FH-4 | CACNA1H | MRA |
17.3.8 16.3.8 PA 治療
| 病因 | 治療 |
|---|---|
| Unilateral aldosterone-producing adenoma | Adrenalectomy |
| Bilateral idiopathic hyperaldosteronism (IHA) | MRA (Spironolactone / Eplerenone) |
| FH-1 (GRA / DSH) | Dexamethasone (suppress ACTH-driven aldosterone) |