㉮ 고혈압, ㉯ 설명할 수 없는 저칼륨혈증, ㉰ 대사성 알칼리증의 triad가 있는 환자에서 primary mineralocorticoid excess의 존재를 의심해야 합니다. 그러나 primary mineralocorticoid excess가 있는 대부분의 환자는 칼륨 수치가 정상이며, 거의 없지만 일부는 저칼륨혈증이면서 혈압은 정상입니다(주로 젊은 성인 여성). 요즈음 primary aldosteronism 환자의 9 ~ 37 %만이 저칼륨혈증인 것으로 평가됩니다. 이것은 많은 고혈압 환자들이 primary aldosteronism에 대한 case-detection test로서 PAC/PRA ratio 검사를 받아 조기 진단되는 것과 관련이 있는 것 같습니다.
The initial evaluation should consist of documenting that the PRA or PRC is suppressed (PRA <1 ng/mL/hour; PRC less than the lower limit of reference range) and that the PAC is inappropriately high for the PRA (typically >15 ng/dL, but as low as 10 ng/dL). Measurements of the plasma renin activity (PRA) (or plasma renin concentration [PRC]) and plasma aldosterone concentration (PAC) are obtained in the morning in a seated ambulatory patient.
Primary aldosteronism should be suspected when PRA is suppressed to <1 ng/mL/hour (or PRC is below the lower limit of normal) and PAC is ≥10 ng/dL (277 pmol/L) (algorithm). The PAC/PRA ratio is usually >20 ng/dL per ng/mL/hour (>555 pmol/L per ng/mL/hour). Most patients require confirmatory testing. In one study, the combination of a PAC above 20 ng/dL (555 pmol/L) and a PAC/PRA ratio above 30 had a sensitivity and specificity of 90 percent for the diagnosis of APA].
Case-detection testing for diagnosis of primary aldosteronism
HTN: hypertension; BP: blood pressure; PAC: plasma aldosterone concentration; PRA: plasma renin activity; PRC: plasma renin concentration.
* Patient out of bed for at least two hours and seated for at least 5 to 15 minutes before sample is drawn.
¶ Direct PRC can be measured instead of PRA. However, UpToDate authors prefer PRA. Refer to UpToDate topic on diagnosis of primary aldosteronism for interpretation of PRC cutoffs and normal values.
Δ Oral sodium loading over three days is one confirmation test that many experts use. An alternative is the saline infusion test. Details of both are reviewed in the UpToDate topic on diagnosis of primary aldosteronism.
Primary hyperaldosteronism is diagnosed when there is an increased ratio (>20) of morning aldosterone to plasma renin activity(Figure). Except as noted in the figure, one of four tests (usually salt loading) is used to confirm primary hyperaldosteronism by demonstrating a lack of aldosterone suppression.
Algorithm for the diagnosis and treatment of primary aldosteronism (hyperaldosteronism).
Cross-filled circles indicate the quality of evidence, such that ⊕○○○ denotes very low quality evidence; ⊕⊕○○, low quality; ⊕⊕⊕○, moderate quality; and ⊕⊕⊕⊕, high quality. ARR = aldosterone-to-renin ratio; AVS = adrenal venous sampling; CT = computed tomography; MR = mineralcorticoid receptor; PA = primary aldosteronism. (Reprinted, with slight modification of text, from Funder JW, Carey RM, Mantero F, et al. The management of primary aldosteronism: case detection, diagnosis, and treatment: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2016;101:1889-916.)
REF. UpToDate 2019.12.29
Goldman-Cecil Medicine 26th edition
