Background. Despite being widely recognized as the most common form of secondary hypertension, the true prevalence of primary aldosteronism (PA) and its main subtypes, aldosterone-producing adenoma (APA) and bilateral adrenal hyperplasia (BAH), among the general hypertensive population remains a matter of debate. Objectives. To determine the prevalence and clinical phenotype of PA in a large cohort of unselected hypertensive patients, consecutively referred to our Hypertension Unit, by 19 general practitioners from Torino, Italy. Methods. Patients were screened for PA using the serum aldosterone to plasma renin activity ratio after withdrawal from all interfering medications and PA was diagnosed according to the Endocrine Society guidelines. The diagnosis was confirmed/excluded by an i.v. saline infusion test or captopril challenge test and subtype differentiation was performed by adrenal CT scanning and adrenal vein sampling (AVS) using strict criteria to define both successful cannulation and lateralization of aldosterone production. Results. A total of 1,672 primary care hypertensive patients, 569 newly diagnosed hypertensives and 1,103 patients already diagnosed with arterial hypertension, were included in the study. A total of 99 patients (5.9%) were diagnosed with PA and conclusive subtype differentiation by AVS was made in 91 patients (27 patients with an APA and 64 patients with BAH). The overall prevalence of PA increased with the severity of hypertension, from 3.9% in hypertensives stage I to 11.8% in hypertensives stage III. Patients with PA more frequently displayed target organ damage and cardiovascular events compared to non-PA hypertensives, independent of confounding variables. Conclusions.The results from the present study demonstrated that PA is a frequent cause of secondary hypertension even in the general hypertensive population and indicates that the majority of hypertensive patients should be screened for PA. Keywords: Primary aldosteronism, aldosterone-producing adenoma, bilateral adrenal hyperplasiaAbbreviation list AC = aldosterone concentration APA = aldosterone-producing adenoma AVS = adrenal vein sampling ARR = serum aldosterone to plasma renin activity ratio BAH = bilateral adrenal hyperplasia CV events = cardiovascular events GP = general practitioner HT = hypertension LREH = low renin essential hypertensives MRA= mineralocorticoid receptor antagonist PA = primary aldosteronism PATO = primary aldosteronism in Torino Condensed AbstractThe prevalence of primary aldosteronism (PA) among general hypertensive population remains unknown. We screened 1,672 primary care hypertensives and 5.9% were diagnosed with PA (27 3 with an aldosterone-producing adenoma and 64 with bilateral adrenal hyperplasia). PA prevalence increased with the severity of hypertension, from 3.9% in hypertensives stage I to 11.8% in stage III. PA patients more frequently displayed target organ damage and cardiovascular events compared to non-PA hypertensives. The study demonstrated that PA is a frequent cause ...

Our findings confirm a negative effect of aldosterone excess on glucose metabolism and suggest that the recently reported higher rates of cardiovascular events in primary aldosteronism than in essential hypertension might be due to increased prevalence of the metabolic syndrome in the former condition.

This study demonstrates in a large population of patients the pathogenetic role of aldosterone excess in the cardiovascular system and thus the importance of early diagnosis and targeted PA treatment.

RABBIA, FRANCO, BERNARD SILKE, ANDREA CONTERNO, TIZIANA GROSSO, BARBARA DE VITO, IVANA RABBONE, LIVIO CHIANDUSSI, AND FRANCO VEGLIO. Assessment of cardiac autonomic modulation during adolescent obesity. Obes Res. 2003; 11:541-548. Objective: To investigate the cardiovascular autonomic function in pediatric obesity of different duration by using standard time domain, spectral heart rate variability (HRV), and nonlinear methods. Research Methods and Procedures: Fifty obese children (13.9 Ϯ 1.7 years) were compared with 12 lean subjects (12.9 Ϯ 1.6 years). Obese children were classified as recent obese (ROB) (Ͻ4 years), intermediate obese (IOB) (4 to 7 years), and long-term obese (OB) (Ͼ7 years). In all participants, we performed blood pressure (BP) measurements, laboratory tests, and 24-hour electrocardiogram/ambulatory BP monitoring. The spectral power was quantified in total power, very low-frequency (LF) power, high-frequency (HF) power, and LF to HF ratio. Total, long-term, and short-term time domain HRV were calculated. Poincaré plot and quadrant methods were used as nonlinear techniques. Results: All obese groups had higher casual and ambulatory BP and higher glucose, homeostasis model assessment, and triglyceride levels. All parameters reflecting parasympathetic tone (HF band, root mean square successive difference, proportion of successive normal-to-normal intervals, and scatterplot width) were significantly and persistently reduced in all obese groups in comparison with lean controls. LF normalized units, LF/HF, and cardiac acceleration (reflecting sympathetic activation) were significantly increased in the ROB group. In IOB and OB groups, LF, but not nonlinear, measures were similar to lean controls, suggesting biphasic behavior of sympathetic tone, whereas nonlinear analysis showed a decreasing trend with the duration of obesity. Long-term HRV measures were significantly reduced in ROB and IOB. Discussion: Autonomic nervous system changes in adolescent obesity seem to be related to its duration. Nonlinear methods of scatterplot and quadrant analysis permit assessment of autonomic balance, despite measuring different aspects of HRV.

Abstract-Primary aldosteronism is a specifically treatable and potentially curable form of secondary hypertension. The aldosterone/plasma renin activity ratio (ARR) is routinely used as a screening test. Antihypertensive therapy can interfere with the interpretation of this parameter, but a correct washout period can be potentially harmful. We have investigated the effects of therapy with atenolol, amlodipine, doxazosin, fosinopril, and irbesartan on the ARR in a group of 230 patients with suspected primary aldosteronism. The percent change from control of ARR in patients taking amlodipine was Ϫ17%Ϯ32; atenolol, 62%Ϯ82; doxazosin, Ϫ5%Ϯ26; fosinopril, Ϫ30%Ϯ24; and irbesartan, Ϫ43%Ϯ27. The ARR change induced by atenolol was significantly higher compared with that induced by all other drugs (PϽ0.0001), and the ARR change induced by irbesartan was significantly lower than that induced by doxazosin (PϽ0.0001). One of 55 patients from the group taking amlodipine (1.8%) and 4/17 of the patients taking irbesartan (23.5%) gave a false-negative ARR (Ͻ50). None of the patients of the groups taking fosinopril, doxazosin, and atenolol displayed a false-negative ARR. Doxazosin and fosinopril can be used in hypertensive patients who need to undergo aldosterone and PRA measurement for the diagnosis of primary aldosteronism; amlodipine gave a very small percentage of false-negative diagnoses. ␤-Blockers also do not interfere with the diagnosis of primary aldosteronism, but they can be responsible for an increased rate of false-positive ARRs. The high rate of false-negative diagnoses in patients undergoing irbesartan treatment requires confirmation in a higher number of patients.