Endocrine Abstracts

It has been well known the primary aldosteronism (PA) is the most common endocrine hypertension, and it is accounted approximately 10% of all hypertensive patients. It is always challenging for physicians which tests we should select for the confirmatory tests for the patients with aldosterone-renin retio (ARR) positive. We analyzed our 83 PA patients for the sensitivity of each confirmatory test.

We screened those PA suspicious patients by ARR and we considered ARR≧20 as positive. We, then, performed the confirmatory tests, such as rapid ACTH stimulating, captopril challenge, upright plus furosemide, and saline infusion tests. When any of those confirmatory tests were positive, the patients undergo an adrenal CT scan. When surgical treatment was practicable and desired, the distinction between unilateral (UHA) and bilateral hyper aldosteronism (BHA) was made by the ACTH-loading adrenal venous sampling (AVS).

The mean age was 55.8±13.4 years old including 33 males and 50 females. The sensitivity of those four confirmatory tests among 65 AVS performed cases were 91.5%, 52.6%, 78.8%, and 29.6%, respectively, and the rapid ACTH stimulating test showed the highest sensitivity in UHA. Fifty-five out of 65 AVS performed cases showed plasma aldosterone concentration ≧1,400 ng/dl in either (46.2%) or both (46.2%) side, and 18 cases showed the ratio of PAC/cortisol in higher side to one in lower side >2.6, which we consider the laterality positive and performed laparoscopic adrenalectomy.

The reason of the sensitivity of saline infusion test is low may be that our daily salt consumption is higher than most countries and this may push down the sensitivity. In conclusion, our results confirm the usefulness of the confirmatory tests, and revealed the sensitivity of rapid ACTH test was high and saline infusion test was low. This indicate that each country should confirm which confirmatory tests are useful under its’ food culture.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.