Michele Bardini

Arterial stiffness, intima-media thickness and carotid artery fibrosis in patients with primary aldosteronism

Objectives To evaluate vascular wall structure and conduit artery stiffness in patients with primary aldosteronism. Methods This observational study, conducted in a University Hypertension Center, evaluated the carotid wall by 2-D ultrasonography and ultrasonic tissue characterization, and analyzed arterial stiffness by applanation tonometer. Twenty-three consecutive patients with primary aldosteronism, 24 matched patients with essential hypertension and 15 controls were studied. Intima-media thickness and corrected integrated backscatter signal of the carotid arteries were evaluated. Radial and femoral pulse wave velocity and aortic augmentation index were also investigated. Results Intima-media thickness in patients with essential hypertension (0.69 ± 0.03 mm) was higher (P < 0.04) than that in controls (0.59 ± 0.02 mm). This finding was more evident in primary aldosteronism patients (0.84 ± 0.03 mm), in whom intima-media thickness was greater than that in controls (P < 0.0001) or in patients with essential hypertension (P < 0.01). Similarly, corrected integrated backscatter signal in patients with essential hypertension (−23.6 ± 0.35 dB) was higher (P < 0.0001) than that in controls (−26.2 ± 0.44 dB), but it was even more elevated in patients with primary aldosteronism (−22.1 ± 0.46 dB), who showed greater corrected integrated backscatter signal than was the case in patients with essential hypertension (P < 0.009) or in controls (P < 0.0001). Femoral pulse wave velocity was higher in primary aldosteronism patients (10.8 ± 0.57 m/s) than in patients with essential hypertension (9.1 ± 0.34 m/s, P < 0.03) or in controls (7.1 ± 0.51 m/s, P < 0.0001). Femoral pulse wave velocity was lower in controls than in patients with essential hypertension (P < 0.0001). The same pattern was observed for radial pulse wave velocity. Aortic augmentation index was higher in primary aldosteronism patients (28.2 ± 2.1%) than in patients with essential hypertension (26.0 ± 1.8%) or in controls (16.8 ± 2.0%, P < 0.001). Patients with essential hypertension likewise exhibited higher aortic augmentation index than controls (P < 0.001). Conclusion Aldosterone excess is responsible per se for vascular morphological (wall thickening and carotid artery fibrosis) and functional (central stiffness) damage.

Plasma and urine aldosterone to plasma renin activity ratio in the diagnosis of primary aldosteronism.

Objective To establish the best cut-off value of the aldosterone (ALD)/plasma renin activity (PRA) ratio when screening patients for primary aldosteronism. One hundred and six patients with primary aldosteronism and 100 essential hypertensive patients were investigated in rigorous standardized conditions. Methods The ALD/PRA cut-off values were calculated from both the plasma and urine ALD/PRA ratio and analyzed by receiver operating characteristic (ROC) curve. In patients with PRA below 0.2 ng/ml/h [our radioimmunoassay detection limit], values were calculated both with PRA levels set at 0.2 ng/ml/h (‘adjusted’) and with PRA levels detected (‘unadjusted’) in the assay. Results ROC analysis on the ALD/PRA ratio indicated that the best performance was obtained when the plasma ALD (ng/dl)/PRA ratio was used in comparison with that observed in the urine ALD (μg/day)/PRA ratio. In patients with primary aldosteronism, as a whole group, the cut-off value of 69 corresponded to the best compromise value between sensitivity (96%) and specificity (85%), with and without PRA adjustment. In patients with aldosterone-producing adenoma, the cut-off to obtain 100% sensitivity with high specificity (85%) proved to be 69, with and without PRA adjustment. In patients with bilateral adrenal hyperplasia, both with and without PRA adjustment, the best compromise between sensitivity (94%) and specificity (86%) was a cut-off value of 71. Conclusion The best cut-off to identify patients with primary aldosteronism, corresponding to 69, was obtained by using the plasma ALD/PRA ratio. Adjustment of PRA to 0.2 ng/ml/h does not interfere with calculation of the plasma ALD/PRA ratio cut-off.

Genome-wide association study identifies CAMKID variants involved in blood pressure response to losartan: the SOPHIA study

BACKGROUND Essential hypertension arises from the combined effect of genetic and environmental factors. A pharmacogenomics approach could help to identify additional molecular mechanisms involved in its pathogenesis. AIM The aim of SOPHIA study was to identify genetic polymorphisms regulating blood pressure response to the angiotensin II receptor blocker, losartan, with a whole-genome approach. MATERIALS & METHODS We performed a genome-wide association study on blood pressure response in 372 hypertensives treated with losartan and we looked for replication in two independent samples. RESULTS We identified a peak of association in CAMK1D gene (rs10752271, effect size -5.5 ± 0.94 mmHg, p = 1.2 × 10(-8)). CAMK1D encodes a protein that belongs to the regulatory pathway involved in aldosterone synthesis. We tested the specificity of rs10752271 for losartan in hypertensives treated with hydrochlorothiazide and we validated it in silico in the GENRES cohort. CONCLUSION Using a genome-wide approach, we identified the CAMK1D gene as a novel locus associated with blood pressure response to losartan. CAMK1D gene characterization may represent a useful tool to personalize the treatment of essential hypertension.

Unique association of non-functioning pheochromocytoma, ganglioneuroma, adrenal cortical adenoma, hepatic and vertebral hemangiomas in a patient with a new intronic variant in the VHL gene.

We analyzed the clinical, hormonal, immunohistochemical and genetic features in a 69-yr-old Caucasian woman with a very rare “composite and mixed pheochromocytoma”. This was characterized by right adrenal pheochromocytoma associated with homolateral ganglioneuroma and controlateral adrenal cortical adenoma. The three tumors, incidentally discovered, proved to be non-functioning (normal secretion of catecholamines and of other neuroendocrine peptides, glucocorticoids, mineralcorticoids and androgens). Accordingly, the patient showed no sign or symptom of endocrine disease. Computed tomography (CT) and magnetic resonance (MR) demonstrated a typical adenomatous lesion on the left adrenal gland with precocious uptake of the radiotracer on radioidine (131I)-norcholesterol adrenal scintigraphy, while the controlateral gland showed hyperdensity on CT, hyperintensity on MR and no uptake at adrenal scintigraphy. In addition, CT and MR revealed a vertebral and two hepatic hemangiomas. The right adrenal gland was surgically removed and, microscopically, pheochromocytoma and ganglioneuroma areas appeared intermixed without a predominant component. The former showed strong immunoreactivity for chromogranin, synaptophysin, vascular endothelial growth factor (VEGF) and CD34, while the latter appeared positive for neuron-specific enolase (NSE) and S−100. Peripheral blood genomic DNA analysis revealed a new intronic variant (5557A>G) in the von Hippel-Lindau gene (VHL) not observed in our control population.

Normalization of catecholamine production following resection of phaeochromocytoma positively influences carotid vascular remodelling

OBJECTIVE To evaluate the influence of plasma catecholamines on the vascular structure in humans, the effects of catecholamine normalization on the carotid wall of patients with phaeochromocytoma (PHEO) were investigated. A prospective study in patients with PHEO before and after (first follow-up: 20.5+/-1.8 months, second follow-up: 31.5+/-2.2 months) successful surgery was conducted in the University Referral Center for Blood Pressure Diseases. Ten consecutive patients with PHEOs and ten age- and blood pressure-matched controls were investigated. Intima-media thickness (IMT) by two-dimensional conventional ultrasonography and corrected ultrasonic integrated backscatter signal (C-IBS) analysis of carotid arteries were investigated in basal conditions and after mass removal. RESULTS In PHEOs, at variance with the expected reduction in metanephrines and catecholamines, no variation in body weight, blood pressure and lipid profile was observed after operation. IMT and C-IBS values in patients with PHEO were greater (at least P<0.01) than in controls. At long-term follow-up after surgery, a significant reduction in mean carotid IMT (P<0.0009) and C-IBS (P<0.009) values was observed. A significant correlation (r=0.54, P<0.03) was found between absolute reduction in C-IBS values and absolute decrement in urinary normetanephrine levels. CONCLUSIONS Our study shows that normalization of catecholamine levels after the removal of PHEO improves carotid IMT and reduces carotid wall fibrosis even without influencing blood pressure and lipid profile. These findings confirm that high catecholamine tone in humans directly influences vascular remodelling of carotid arteries.

Plasma and tissue chromogranin in patients with adrenocortical adenomas

Adrenal adenomas frequently arise from cortical islets in the medulla, and these islets seem to present a greater risk for pathological growth than cortical cells within the adrenal cortex. Chromogranin A (CgA), a glycoprotein co-stored in secreting granules and co-released with resident hormones of chromaffin cells, behaves as a prohormone, generating several biologically active peptides capable of influencing growth, morphogenesis and progression of endocrine tumors. The aim of our study was to investigate whether chromaffin cells may be involved in the development and growth of adrenocortical adenomas. We enrolled 19 patients (12 females and 7 males, mean±SD age 54.9±11.2 yr, age range 34–75 yr) with incidental, non-functioning, benign adrenocortical adenomas, and measured circulating levels of CgA, catecholamines and creatinine before and 2 months after surgery. Plasma CgA was evaluated by immunoradiometric assay. Testing for CgA immunoreactivity in the removed tissues was performed by immunohistochemical analysis. Mean plasma CgA did not significantly change following surgery (before 73.7±15.2 ng/ml; after 68.9±14.8 ng/ml). Individual CgA values indicated that 4 patients had plasma CgA levels above our cut-off of normality. After mass removal, CgA further increased in 2 cases, decreased in 1 and normalized in 1. No variation in CgA levels was found in the other patients. No correlation was observed between CgA and the variables measured, except between CgA and plasma creatinine (r=0.472, p<0.05). Histopathological evaluation revealed adrenocortical adenomas in all cases and immunohistochemical analysis detected no CgA immunoreactivity in any specimen.Our results show that in human adrenocortical adenomas CgA is not expressed and that removal of the mass does not modify plasma CgA levels. For these reasons the endocrine involvement of local CgA in adrenocortical tumorigenesis is unlikely.

Preclinical cardiac involvement in phaeochromocytoma: a study with integrated backscatter

Objective  It is well known that vascular and cardiac structure may be influenced by circulating neurohormonal factors. Our aim was to study the myocardial wall texture by integrated backscatter (IBS) analysis in patients with phaeochromocytoma (PHEO).

Conceptual basis and methodology of the SOPHIA study

To clarify the role of gene polymorphisms on the effect of losartan and losartan plus hydrochlorothiazide on blood pressure (primary end point) and on cardiac, vascular and metabolic phenotypes (secondary end point) after 4, 8, 12, 16 and 48 weeks treatment, an Italian collaborative study - The Study of the Pharmacogenomics in Italian hypertensive patients treated with the Angiotensin receptor blocker losartan (SOPHIA) - on never-treated essential hypertensives (n = 800) was planned. After an 8 week run-in, losartan 50 mg once daily will be given and doubled to 100 mg at week +4 if blood pressure is more than 140/90 mmHg. Hydroclorothiazide 25 mg once daily at week +8 and amlodipine 5 mg at week +16 will be added if blood pressure is more than 140/90 mmHg. Cardiac mass (echocardiography), carotid intima-media thickness, 24 h ambulatory blood pressure, homeostatic model assessment (HOMA) index, microalbuminuria, plasma renin activity and aldosterone, endogenous lithium clearance, brain natriuretic peptide and losartan metabolites will be evaluated. Genes of the renin-angiotensin-aldosterone system, salt sensitivity, the beta-adrenergic system and losartan metabolism will be studied (Illumina custom arrays). A whole-genome scan will also be performed in half of the study cohort (1M array, Illumina 500 GX beadstation).

L’edema ciclico idiopatico. Realtà o fantasia?

RiassuntoL’edema ciclico idiopatico è una sindrome non infiammatoria caratterizzata da un obiettivo incremento ponderale o dalla percezione soggettiva di aumento del peso corporeo per cause non precisate. La sindrome colpisce pressoché esclusivamente il sesso femminile nella vita riproduttiva, e si caratterizza per la sensazione di tensione generalizzata e ritenzione idrica in posizione ortostatica. L’escursione ponderale giornaliera è variabile, ma può raggiungere anche svariati chilogrammi. Poco si sa sulla genesi della malattia, anche se, verosimilmente, numerosi fattori possono concorrere in varia misura, come una attivazione del sistema renina-angiotensina, disturbi ipotalamici, alterazioni dopaminergiche sistemiche o renali e alterazioni anatomiche della parete vascolare con aumento della permeabilità capillare. Non raramente la malattia si instaura in pazienti con disturbi della condotta alimentare o comunque con alterazione del tono dell’umore e spesso è aggravata dall’uso di farmaci (diuretici, lassativi) che, assunti con lo scopo di perdere peso, aggravano poi la sintomatologia iniziale. La diagnosi di edema idiopatico è da porre dopo avere escluso tutte le altre forme note di edema localizzato o generalizzato. I provvedimenti terapeutici sono concentrati sul controllo del peso corporeo tramite una dieta povera di sodio, limitata nei carboidrati e generosa nei liquidi, il mantenimento giornaliero di posizione clinostatica alternat o a lunghe camminate e talora l’elastocompressione degli arti inferiori. Dal punto di vista farmacologico, è stato proposto l’uso di ACE-inibitori o antialdosteronici, senza peraltro durevoli successi, mentre i diuretici dell’ansa, i farmaci dopaminergici e soprattutto le amine simpaticomimetiche sembrano del tutto inutili e talora ricchi di effetti collaterali.