Determination of adrenal hypersecretion in primary Aldosteronism without aldosterone-production adenomas.

BACKGROUND: Primary aldosteronism (PA) is highly prevalent in hypertensive population. Adrenal vein sampling (AVS) is the only procedure to assess adrenal aldosterone hypersecretion in PA. PA patients without aldosterone-producing adenomas (APA) frequently have unilateral aldosterone hypersecretion (UAH). These patients could bear inappropriate adrenalectomy without AVS. This study aims to identify which clinical characteristics should be recommended to perform AVS in these PA patients. METHODS: This study was performed from January 2018 to July 2019 at a center for hypertension and metabolic diseases. Adrenal computed tomography (CT) scan, biochemical evaluation, and AVS were performed. RESULTS: Total 141 patients were included in this study. Aldosterone to renin ratio (ARR) after confirmatory test is highly associated with adrenal laterality. The specificity of ARR > 10 (ng/dL)/(mU/L) after confirmatory test is 100%. After confirmatory test, patients with ARR > 10 (ng/dL)/(mU/L) had higher plasma aldosterone concentration and incidences of ischemic heart diseases and renal damage(p < 0.05). CONCLUSIONS: After confirmatory tests, ARR > 10 (ng/dL)/(mU/L) indicates adrenal laterality, with increasingly cardiorenal damage in PA patients without APA. Thus, AVS should be recommended in these patients before surgery. TRIAL REGISTRATION: NCT03398785 , Date of Registration: December 24, 2017.

Adrenal artery ablation for primary aldosteronism without apparent aldosteronoma: An efficacy and safety, proof-of-principle trial.

Primary aldosteronism (PA) is associated with resistant hypertension and cardiovascular events. There are some limitations of current medical and surgical therapies for PA. To determine the efficacy and safety of catheter-based adrenal artery ablation for treatment of PA patients who refused both surgery and medical therapy, we performed this prospective cohort study. Thirty-six PA patients without apparent aldosteronoma were treated by adrenal artery ablation. Primary outcome was postoperative blood pressure and defined daily dose (DDD) of antihypertensive medications after adrenal ablation. Secondary outcome was biochemical success. We assessed outcomes based on Primary Aldosteronism Surgical Outcome (PASO) criteria. Adrenal CT scan, biochemical evaluation, adrenal artery ablation and adrenal venous sampling (AVS) were underwent. After adrenal ablation, complete clinical success (normotension without antihypertensive medication) was achieved in 9/36 (25.0%) patients and partial clinical success (reduction in blood pressure or less antihypertensive medication) in 13/36 (36.1%) patients. Complete biochemical success (correction of hypokalemia and normalization of aldosterone-to-renin ratio) was achieved in 16/36 (44.4%) patients. Office-based and ambulatory blood pressures were reduced by 17/7 and 11/2 mmHg at 6 months after ablation, respectively. The plasma cortisol level in the ablation group decreased slightly, but no patient developed hypoadrenocorticism. Catheter-based adrenal ablation appears to produce substantial and sustained blood pressure reduction and biochemical improvement, with only minor adverse events in PA patients without apparent aldosteronoma. This therapy could be an important supplement for current PA treatments.

Activation of Transient Receptor Potential Channel Vanilloid 4 by DPP-4 (Dipeptidyl Peptidase-4) Inhibitor Vildagliptin Protects Against Diabetic Endothelial Dysfunction.

Endothelial dysfunction is an early step to the progression of cardiovascular diseases in diabetes. Apart from their anti-diabetic action, DPP-4 (dipeptidyl peptidase-4) inhibitors also reduce cardiovascular events in diabetic patients. However, the underlying mechanism of the beneficial effect of DPP-4 inhibitor on endothelial function is still obscure. In this study, we intervened type 1 or 2 diabetic model mice with vildagliptin for 4 weeks and measured the vascular reactivity. We found that vildagliptin improved endothelium-dependent vasodilation in diabetic mice independent of GLP-1 (glucagonlike peptide-1), but this effect was blocked by a SIRT1 (Sirtuin 1) inhibitor, Ex527. Mechanistically, vildagliptin-activated Transient Receptor Potential Channel Vanilloid 4 (TRPV4) to promote extracellular calcium uptake in endothelial cells, which activated AMPK (AMP-activated protein kinase)/SIRT1 pathway to counteract hyperglycemia-induced endothelial reactive oxygen species generation and senescence. Vildagliptin directly binds to TRPV4 by forming a hydrogen bond, which is critical to vildagliptin-evoked endothelial calcium intake. Knockout or inhibition of TRPV4 erased the beneficial role of vildagliptin. In addition, activation of SIRT1 by SRT1720 improved endothelial function independent of TRPV4 and reduced TRPV4 transcription to maintain an appropriate calcium level. In summary, our findings prove that vildagliptin protects against hyperglycemia-induced endothelial dysfunction by activating TRPV4-meditaed Ca2+ uptake, which helps to re-understand the mechanism of DPP-4 inhibitors and expand the therapeutic scope.