Quantitative value of aldosterone-renin ratio for detection of aldosterone-producing adenoma: The Aldosterone-Renin Ratio for Primary Aldosteronism (AQUARR) study

Background Current guidelines recommend use of the aldosterone\u2010renin ratio (ARR) for the case detection of primary aldosteronism followed by confirmatory tests to exclude false\u2010positive results from further diagnostic workup. We investigated the hypothesis that this could be unnecessary in patients with a high ARR value if the quantitative information carried by the ARR is taken into due consideration. Methods and Results We interrogated 2 large data sets of prospectively collected patients studied with the same predefined protocol, which included the captopril challenge test. We used an unambiguous diagnosis of aldosterone\u2010producing adenoma as reference index. We also assessed whether the post\u2010captopril ARR and plasma aldosterone concentration fall furnished a diagnostic gain over baseline ARR values. We found that the false\u2010positive rate fell exponentially, and, conversely, the specificity increased with rising ARR values. At receiver operating characteristics curves and diagnostic odds ratio analysis, the high baseline ARR values implied very high positive likelihood ratio and diagnostic odds ratio values. The baseline and post\u2010captopril ARR showed similar diagnostic accuracy (area under the receiver operating characteristics curve) in both the exploratory and validation cohorts, indicating lack of diagnostic gain with this confirmatory test (between\u2010area under the curve difference, 0.005; 95% CI, 120.031 to 0.040; P=0.7 for comparison, and 0.05; 95% CI, 120.061 to 0.064; P=0.051 for comparison, respectively). Conclusions These results indicate that the ARR conveys key quantitative information that, if properly used, can simplify the diagnostic workup, resulting in saving of money and resources. This can offer the chance of diagnosis and ensuing adrenalectomy to a larger number of hypertensive patients, ultimately resulting in better control of blood pressure

A rare combination consisting of aldosterone-producing adenoma and adrenal myelolipoma in a patient with heterozygosity for retinoblastoma (RB) gene

Various pathological disorders have been associated with primary aldosteronism, including glucagonoma, phaeochrornocytoma and primary hyperparathyroidism. In this report, a case of adrenal myelolipoma (a rare non-functioning turnout composed of mature adipose tissue and normal haematopoietic elements similar to bone marrow cells), aldosterone-producing adenoma and a pituitary microadenoma coexisting in a 62-year-old man with a 15-year history of arterial hypertension, previous ablation of an autonomously-functioning thyroid adenoma, multiple lipomas and an heterozygosity of the retinoblastoma (RB) susceptibility gene is reported. We believe that this case probably represents another variant of the multiple neoplasia syndrome and we speculate that structural alteration of the RB gene may play a role in the tumorogenesis

High plasma adrenomedullin concentrations in patients with high-renin essential hypertension

Adrenomedullin (AM) is a novel peptide, first isolated from human phaeochromocytoma, which elicits a long-lasting vasorelaxant activity. Recently, it has been reported that endothelial cells produce AM and that immunoreactive AM plasma levels may be elevated in human arterial hypertension, although the exact pathophysiological role of AM remains to be established. The aim of our study was to determine the relationship between the components of the renin-angiotensin-aldosterone system (RAAS) and plasma AM levels in patients with low-, medium- or high-renin essential hypertension. The study groups included 10 patients with low-renin essential hypertension (average age 42+/-15 years), nine patients with medium-renin essential hypertension (46+/-13 years), I I patients with high-renin essential hypertension (42+/-14 years) and 12 healthy subjects (43 1 1 years). Our results demonstrated that the mean AM values of all patients with essential hypertension were 10.85+/-3.14 pg/ml; there was a statistical correlation (r=0.705; p<0.001) between plasma renin activity (PRA) and AM levels in hypertensives. In patients with high-renin essential hypertension, plasma AM levels (14.2+/-2.2 pg/ml) were significantly higher (p<0.001) than those of healthy subjects (8.7+/-2.1 pg/ml), patients with medium-renin essential hypertension (8.5+/-1.4 pg/ml), and patients with low-renin essential hypertension (9.1+/-1.5 pg/ml). There was no statistical difference in AM concentrations between medium- and low-renin hypertensive patients. In conclusion, we have found that, in hypertensive patients, plasma AM levels were increased only in high-renin individuals, suggesting a role of AM in this particular form of human essential hypertension

A prospective study of the prevalence of primary aldosteronism in 1,125 hypertensive patients

OBJECTIVES We prospectively investigated the prevalence of curable forms of primary aldosteronism (PA) in newly diagnosed hypertensive patients. BACKGROUND The prevalence of curable forms of PA is currently unknown, although retrospective data suggest that it is not as low as commonly perceived. METHODS Consecutive hypertensive patients referred to 14 hypertension centers underwent a diagnostic protocol composed of measurement of Na+ and K+ in serum and 24-h urine, sitting plasma renin activity, and aldosterone at baseline and after 50 mg captopril. The patients with an aldosterone/renin ratio > 40 at baseline, and/or > 30 after captopril, and/or a probability of PA (by a logistic discriminant function) >= 50% underwent imaging tests and adrenal vein sampling (AVS) or adrenocortical scintigraphy to ident4 the underlying adrenal pathology. An aldosterone-producing adenoma (APA) was diagnosed in patients who in addition to excess autonomous aldosterone secretion showed: 1) lateralized aldosterone secretion at AVS or adrenocortical scintigraphy, 2) adenoma at surgery and pathology, and 3) a blood pressure decrease after adrenalectomy. Evidence of excess autonomous aldosterone secretion without such criteria led to a diagnosis of idiopathic hyperaldosteronism (IHA). RESULTS A total of 1,180 patients (age 46 +/- 12 years) were enrolled; a conclusive. diagnosis was attained in 1,125 (95.3%). Of these, 54 (4.8%) had an APA and 72 (6.4%) had an IHA. There were more APA (62.5%) and fewer IHA cases (37.5%) at centers where AVS was available (p = 0.002); the opposite occurred where AVS was unavailable. CONCLUSIONS In newly diagnosed hypertensive patients referred to hypertension centers, the prevalence of APA is high (4.8%). The availability of AVS is essential for an accurate identification of the adrenocortical pathologies underlying PA