Assessment and management of heart failure in patients with chronic kidney disease.

Heart failure (HF) and chronic kidney disease (CKD) are two pathological conditions with a high prevalence in the general population. When they coexist in the same patient, a strict interplay between them is observed, such that patients affected require a clinical multidisciplinary and personalized management. The diagnosis of HF and CKD relies on signs and symptoms of the patient but several additional tools, such as blood-based biomarkers and imaging techniques, are needed to clarify and discriminate the main characteristics of these diseases. Improved survival due to new recommended drugs in HF has increasingly challenged physicians to manage patients with multiple diseases, especially in case of CKD. However, the safe administration of these drugs in patients with HF and CKD is often challenging. Knowing up to which values ​​of creatinine or renal clearance each drug can be administered is fundamental. With this review we sought to give an insight on this sizable and complex topic, in order to get clearer ideas and a more precise reference about the diagnostic assessment and therapeutic management of HF and CKD.

Acute Kidney Injury at Hospital Admission for SARS-CoV-2 Infection as a Marker of Poor Prognosis: Clinical Implications for Triage Risk Stratification.

BACKGROUND/AIMS: The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a wide spectrum of effects, including acute kidney injury (AKI) in up to 40% of hospitalized patients. Given the established relationship between AKI and poor prognosis, whether AKI might be a prognostic indicator for patients admitted to the hospital for SARS-CoV-2 infection would allow for a straightforward risk stratification of these patients. METHODS: We analyzed data of 623 patients admitted to San Raffaele Hospital (Milan, IT) between February 25 and April 19, 2020, for laboratory-confirmed SARS-CoV-2 infection. Incidence of AKI at hospital admission was calculated, with AKI defined according to the KDIGO criteria. Multivariable Cox regression models assessed the association between AKI and overall mortality and admission to the intensive care unit (ICU). RESULTS: Overall, 108 (17%) patients had AKI at hospital admission for SARS-CoV-2 infection. After a median follow-up for survivors of 14 days (interquartile range: 8, 23), 123 patients died, while 84 patients were admitted to the ICU. After adjusting for confounders, patients who had AKI at hospital admission were at increased risk of overall mortality compared to those who did not have AKI (hazards ratio [HR]: 2.00; p = 0.0004), whereas we did not find evidence of an association between AKI and ICU admission (HR: 0.95; p = 0.9). CONCLUSIONS: These data suggest that AKI might be an indicator of poor prognosis for patients with SARS-CoV-2 infection, and as such, given its readily availability, it might be used to improve risk stratification at hospital admission.

Serum Irisin May Predict Cardiovascular Events in Elderly Patients With Chronic Kidney Disease Stage 3-5.

OBJECTIVE: Irisin is a circulating myokine released from skeletal muscles after physical exercise. Irisin production decreases during the course of chronic kidney disease (CKD) as a potential consequence of sarcopenia and physical inactivity. METHODS: This observational study explored the relationship of serum irisin with cardiovascular outcome in 79 patients with stage 3-5 CKD. RESULTS: Serum irisin was significantly higher in healthy subjects (n = 20) than that in CKD patients (7 ± 2 vs. 3.1 ± 0.9 µg/mL; P = .0001) and was higher in patients with CKD stage 3 (3.2 ± 1 µg/mL) than in patients at stage 4 and 5 taken together (n = 36, 2.8 ± 0.7 µg/mL, P = .05). Patients in the lowest serum irisin tertile had lower serum 1,25(OH)2D levels (21 ± 11 pg/mL) than patients in the middle (30 ± 13 pg/mL; P = .005) and the highest tertile (27 ± 14 pg/mL; P = .047). Patients in the highest tertile had lower Kauppila score (10.6 ± 6.9) than patients in the middle (11.8 ± 5.5; P = .007) and the lowest tertile (6.9 ± 6.8; P = .043). Twenty patients suffered from cardiovascular events during a 3-year follow-up. A Cox regression model using age, body weight, presence of diabetes mellitus, gender, Kauppila calcification score, serum values of FGF23 (as logarithm), phosphate, sclerostin, albumin and cholesterol, estimated glomerular filtration rate, and serum irisin tertiles as covariates showed that patients in the highest tertile of serum irisin had a lower cardiovascular risk than patients in the middle tertile (B, 2.38; odds ratio, 10.8; 95% confidence interval, 1.65-58.13; P = .013) or in the lowest tertile (B, 1.61; odds ratio, 5; 95% confidence interval, 1.09-22.83; P = .038). CONCLUSIONS: These findings suggest that serum irisin may be a marker of cardiovascular outcome in patients with CKD.

Lanosterol Synthase Genetic Variants, Endogenous Ouabain, and Both Acute and Chronic Kidney Injury.

RATIONALE & OBJECTIVE: Studies of humans and animals have suggested that endogenous ouabain (EO) and related genes are mediators of acute (AKI) and chronic kidney injury. We sought to examine the relationship among EO levels, genetic variants in lanosterol synthase (LSS; an enzyme that catalyzes synthesis of cholesterol, a precursor of EO), and both AKI and chronic kidney injury. STUDY DESIGN: 2 prospective observational cohort studies and a cross-sectional study of kidney tissue. SETTING & PARTICIPANTS: (1) A prospective cohort study of patients undergoing cardiovascular surgery, (2) measurement of EO concentration in kidney tissue removed because of an adjacent tumor, and (3) a prospective cohort study of patients with newly diagnosed essential hypertension. EXPOSURE: Missense variant in LSS (A instead of C allele at rs2254524), which leads to a valine to leucine substitution at amino acid 642. OUTCOMES: Development of postoperative AKI in the cardiovascular surgery cohort, EO concentration in kidney tissue, and estimated glomerular filtration rate (eGFR) reductions in the essential hypertension cohort. ANALYTICAL APPROACH: Logistic regression for analysis of postoperative AKI, analysis of variance for EO concentration in kidney tissue, and generalized linear models for changes in eGFR over time. RESULTS: AKI incidence following cardiovascular surgery was greater among those with the LSS rs2254524 AA genotype (30.7%) than in those with the CC genotype (17.4%; P=0.001). LSS rs2254524 AA kidneys had higher EO concentrations than CC kidneys (2.14±0.29 vs 1.25±0.08ng/g; P<0.001). In the longitudinal study of patients with essential hypertension (median follow-up, 4 years; range, 1-15 years), eGFR decline was greater among the LSS rs2254524 AA genotype group (-4.39±1.18mL/min/1.73m2 per year) than in the AC or CC genotype groups (-1.07±0.55 and -2.00±0.45mL/min/1.73m2 per year respectively; P = 0.03). LIMITATIONS: These associations do not necessarily represent causal relationships; LSS rs2254524 variants may have effects on other steroid hormones. CONCLUSIONS: These findings support the potential value of LSS rs2254524 genotype-based risk stratification to identify patients at high risk for AKI before cardiovascular surgery, as well as predict accelerated eGFR in the setting of hypertension. These findings also suggest that LSS may in part drive EO-mediated kidney damage. EO may represent a new potential therapeutic target for the prevention of AKI and slowing of kidney damage in the setting of hypertension.

Reply: "Comment on: Endogenous Ouabain and Related Genes in the Translation from Hypertension to Renal Diseases".

In his recent letter, Dr [...].

Endogenous Ouabain and Related Genes in the Translation from Hypertension to Renal Diseases.

The endogenous ouabain (EO) is a steroid hormone secreted by the adrenal gland with cardio-tonic effects. In this article, we have reviewed and summarized the most recent reports about EO, particularly with regard to how it may interact with specific genetic backgrounds. We have focused our attention on the EO's potential pathogenic role in several diseases, including renal failure, essential hypertension and heart failure. Notably, these reports have demonstrated that EO acts as a pro-hypertrophic and growth-promoting hormone, which might lead to a cardiac remodeling affecting cardiovascular functions and structures. In addition, a possible role of EO in the development of acute kidney injury has been hypothesized. During the last decays, many important improvements permitted a deeper understanding of EO's metabolisms and functions, including the characteristics of its receptor and the effects of its activation. Such progresses indicated that EO has significant implications in the pathogenesis of many common diseases. The patho-physiological role of EO in the development of hypertension and other cardiac and renal complications have laid the basis for the development of a new selective compound that could selectively modulate the genetic and molecular mechanisms involved in EO’s action. It is evident that the knowledge of EO has incredibly increased; however, many important areas remain to be further investigated.

A new clinical multivariable model that predicts postoperative acute kidney injury: impact of endogenous ouabain.

BACKGROUND: Acute kidney injury (AKI) is an important complication of cardiac surgery. Recently, elevated levels of endogenous ouabain (EO), an adrenal stress hormone with haemodynamic and renal effects, have been associated with worse renal outcome after cardiac surgery. Our aim was to develop and evaluate a new risk model of AKI using simple preoperative clinical parameters and to investigate the utility of EO. METHODS: The primary outcome was AKI according to Acute Kidney Injury Network stage II or III. We selected the Northern New England Cardiovascular Disease Study Group (NNECDSG) as a reference model. We built a new internal predictive risk model considering common clinical variables (CLIN-RISK), compared this model with the NNECDSG model and determined whether the addition of preoperative plasma EO improved prediction of AKI. RESULTS: All models were tested on >800 patients admitted for elective cardiac surgery in our hospital. Seventy-nine patients developed AKI (9.9%). Preoperative EO levels were strongly associated with the incidence of AKI and clinical complication (total ICU stay and in-hospital mortality). The NNECDSG model was confirmed as a good predictor of AKI (AUC 0.74, comparable to the NNECDSG reference population). Our CLIN-RISK model had improved predictive power for AKI (AUC 0.79, CI 95% 0.73-0.84). Furthermore, addition of preoperative EO levels to both clinical models improved AUC to 0.79 and to 0.83, respectively (ΔAUC +0.05 and +0.04, respectively, P < 0.01). CONCLUSION: In a population where the predictive power of the NNECDSG model was confirmed, CLIN-RISK was more powerful. Both clinical models were further improved by the addition of preoperative plasma EO levels. These new models provide improved predictability of the relative risk for the development of AKI following cardiac surgery and suggest that EO is a marker for renal vascular injury.

Is denosumab an efficient and safe drug for osteoporosis in dialysis patients? Considerations and state of the art about its use in this setting.

PURPOSE: In patients with chronic kidney disease (CKD), renal osteodystrophy may be associated with a progressive bone mass loss that increases fracture risk. Denosumab, a monoclonal antibody inhibiting osteoclast activity, is an antiresorptive medication used for the treatment osteoporosis. METHODS: Its efficacy and safety were initially established in the FREEDOM study, showing a significant reduction in incident fractures in osteoporotic women treated with denosumab. Subsequent post hoc analyses showed its efficacy in patients stratified by kidney function, but these analyses did not include patients with advanced stages of CKD. The capability of denosumab in improving bone mineral density in uremic patients was evaluated in 12 studies including 461 dialysis patients with low bone mineral density. The improvement of bone mineral density was the final end point in these studies assessed during a follow-up of 6-60 months. Nine of these studies did not have hyperparathyroidism among criteria for patient inclusion and their participants may have low-turnover bone disease. Despite current recommendations, no patients underwent bone biopsy before denosumab therapy. RESULTS: Overall, findings in these studies suggest that denosumab is a viable option for promoting bone mass recovery in patients with advanced stages of CKD having either high or low serum levels of PTH. However, the increase of bone mineral density was lower in patients with low serum markers of bone turnover at baseline. These studies also highlighted the need for calcium and vitamin D supplementation to prevent hypocalcemia that remains a serious concern. CONCLUSIONS: Denosumab emerges as a potentially safe and effective option for enhancing bone health in CKD patients.

Preoperative endogenous ouabain predicts acute kidney injury in cardiac surgery patients.

OBJECTIVES: Acute kidney injury is a frequent complication of cardiac surgery and increases morbidity and mortality. As preoperative biomarkers predicting the development of acute kidney injury are not available, we have tested the hypothesis that preoperative plasma levels of endogenous ouabain may function as this type of biomarker. RATIONALE AND DESIGN: Endogenous ouabain is an adrenal stress hormone associated with adverse cardiovascular outcomes. Its involvement in acute kidney injury is unknown. With studies in patients and animal settings, including isolated podocytes, we tested the above mentioned hypothesis. PATIENTS: Preoperative endogenous ouabain was measured in 407 patients admitted for elective cardiac surgery and in a validation population of 219 other patients. We also studied the effect of prolonged elevations of circulating exogenous ouabain on renal parameters in rats and the influence of ouabain on podocyte proteins both "in vivo" and "in vitro." MAIN RESULTS: In the first group of patients, acute kidney injury (2.8%, 8.3%, 20.3%, p < 0.001) and ICU stay (1.4±0.38, 1.7±0.41, 2.4±0.59 days, p = 0.014) increased with each incremental preoperative endogenous ouabain tertile. In a linear regression analysis, the circulating endogenous ouabain value before surgery was the strongest predictor of acute kidney injury. In the validation cohort, acute kidney injury (0%, 5.9%, 8.2%, p < 0.0001) and ICU stay (1.2±0.09, 1.4±0.23, 2.2±0.77 days, p = 0.003) increased with the preoperative endogenous ouabain tertile. Values for preoperative endogenous ouabain significantly improved (area under curve: 0.85) risk prediction over the clinical score alone as measured by integrate discrimination improvement and net reclassification improvement. Finally, in the rat model, elevated circulating ouabain reduced creatinine clearance (-18%, p < 0.05), increased urinary protein excretion (+ 54%, p < 0.05), and reduced expression of podocyte nephrin (-29%, p < 0.01). This last finding was replicated ex vivo by incubating podocyte primary cell cultures with low-dose ouabain. CONCLUSIONS: Preoperative plasma endogenous ouabain levels are powerful biomarkers of acute kidney injury and postoperative complications and may be a direct cause of podocyte damage.

Profiling Covid-19 patients with respect to level of severity: an integrated statistical approach.

A full understanding of the characteristics of Covid-19 patients with a better chance of experiencing poor vital outcomes is critical for implementing accurate and precise treatments. In this paper, two different advanced data-driven statistical approaches along with standard statistical methods have been implemented to identify groups of patients most at-risk for death or severity of respiratory distress. First, the tree-based analysis allowed to identify profiles of patients with different risk of in-hospital death (by Survival Tree-ST analysis) and severity of respiratory distress (by Classification and Regression Tree-CART analysis), and to unravel the role on risk stratification of highly dependent covariates (i.e., demographic characteristics, admission values and comorbidities). The ST analysis identified as the most at-risk group for in-hospital death the patients with age > 65 years, creatinine [Formula: see text] 1.2 mg/dL, CRP [Formula: see text] 25 mg/L and anti-hypertensive treatment. Based on the CART analysis, the subgroups most at-risk of severity of respiratory distress were defined by patients with creatinine level [Formula: see text] 1.2 mg/dL. Furthermore, to investigate the multivariate dependence structure among the demographic characteristics, the admission values, the comorbidities and the severity of respiratory distress, the Bayesian Network analysis was applied. This analysis confirmed the influence of creatinine and CRP on the severity of respiratory distress.

New Landmarks to Slow the Progression of Chronic Kidney Disease.

Chronic kidney disease (CKD) is a serious condition whose incidence is steadily rising, particularly in the Western world, due to the increasing prevalence of diabetes, hypertension, and obesity, which are nowadays the major causes of CKD in the Western population, as well as the aging of the population [...].

Inverse salt sensitivity: an independent risk factor for cardiovascular damage in essential hypertension.

OBJECTIVE: Salt sensitivity is a powerful risk factor for cardiovascular (CV) disease and mortality in both normotensive and hypertensive patients. We investigated the predictive value of the salt sensitivity phenotype in the development of CV events and hypertensive target organ damage (TOD) among essential hypertensive patients. METHODS: Eight hundred forty-four naive hypertensive patients were recruited and underwent an acute saline test during which blood pressure (BP) displayed either no substantial variation (salt-resistant, SR individuals), an increase (salt-sensitive, SS), or a paradoxical decrease (inverse salt-sensitive, ISS). Sixty-one patients with the longest monitored follow-up (median 16 years) for blood pressure and organ damage were selected for the present study. A clinical score for TOD development based on the severity and the age of onset was set up by considering hypertensive heart disease, cerebrovascular damage, microalbuminuria, and vascular events. RESULTS: CV events were significantly higher among SS and ISS than in SR patients. The relative risk of developing CV events was 12.67 times higher in SS than SR and 5.94 times higher in ISS than SR patients. The development of moderate to severe TOD was 10-fold higher in SS and over 15-fold higher in ISS than in SR patients. Among the three phenotypes, changes in plasma endogenous ouabain were linked with the blood pressure effects of saline. CONCLUSIONS: Salt sensitivity and inverse salt sensitivity appear to be equivalent risk factors for CV events. The response to an acute saline test is predictive of CV damage for newly identified ISS individuals.

[Anti-angiogenic drugs and hypertension: from multidisciplinary collaboration to greater care].

Anti-angiogenic drugs are widely used in cancer therapy. Their main targets of action are the vascular endothelial growth factor (VEGF) and its receptors (VEGF-R). Anti-angiogenic drugs are used to reduce the growth of the tumor and its metastases by acting on the phenomenon of tumor neo-angiogenesis. However, they are known for their side effects such as hypertension, acute kidney injury (AKI), and congestive heart failure. Methods: retrospective study conducted on 57 consecutive patients known for ovarian cancer. Patients treated with Bevacizumab, as first-line, relapse, or maintenance treatment (2015-2022). Results: according to FIGO staging, 98.2% (56 out of 57) of the patients in the study had third degree disease (G3). 49% of patients developed hypertension after starting Bevacizumab therapy (82% grade 2 according to CTCAE v.5). 89% of hypertensive patients started treatment and its management was multidisciplinary with nephrological consultation in 68% of cases. Only 3 out of 57 women discontinued treatment due to hypertension, and in only one of them it was not possible to restart it. Conclusions: the evaluation of the patient by a multidisciplinary team (gynecologist and nephrologist) is essential to minimize the morbidity and mortality of patients, and to avoid the interruption of antineoplastic treatment.

Serum concentrations of free indoxyl and p-cresyl sulfate are associated with mineral metabolism variables and cardiovascular risk in hemodialysis patients.

BACKGROUND: Indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are uremic toxins associated with cardiovascular outcome in CKD patients. The present work is an analysis of the association of serum free, total IS and PCS with cardiovascular events and calcium-phosphate metabolism variables in hemodialysis patients. METHODS: Serum levels of total and free IS and PCS were measured in 139 hemodialysis patients. Their relationship with calcium-phosphate metabolism variables were tested in an observational cohort study. In addition, their association with cardiovascular events was investigated during a 4-year follow-up. RESULTS: Patients in the highest tertile (T3) of serum free IS showed lower serum 1,25(OH)2D compared to patients in the middle (T2) and lowest tertile (T1); in addition to this, T3 patients showed lower serum irisin than T1 patients and lower serum PTH than all the other subjects (T1 + T2) combined. Serum PTH was also measured during the two years after the baseline measurement and was higher in patients in the T1 than in those in the T3 of serum free IS. Cox regression analysis showed that cardiovascular risk was lower in T1 patients than in those in the T3 of serum free PCS, both using a univariate (OR 2.55, 95% CI 1.2-5.43; p = 0.015) or multivariate model (OR 2.48, 95% CI 1.12-5.51; p = 0.003). CONCLUSIONS: Serum free IS may be associated with PTH and 1,25(OH)2D secretion, whereas free PCS may predict cardiovascular risk in hemodialysis patients.

Dissecting the Polygenic Basis of Primary Hypertension: Identification of Key Pathway-Specific Components.

INTRODUCTION AND OBJECTIVES: Genome-wide association studies have identified a high number of genetic loci associated with hypertension suggesting the presence of an underlying polygenic architecture. In this study, we aimed to dissect the polygenic component of primary hypertension searching also for pathway-specific components. METHODS: The polygenic risk score (PRS) models, based on the UK biobank genetic signals for hypertension status, were obtained on a target Italian case/control cohort including 561 cases and 731 hyper-normal controls from HYPERGENES, and were then applied to an independent validation cohort composed by multi-countries European-based samples including 1,284 cases and 960 hyper-normal controls. RESULTS: The resulting genome-wide PRS was capable of stratifying the individuals for hypertension risk by comparing between individuals in the last PRS decile and the median decile: we observed an odds ratio (OR) of 3.62, CI = [2.01, 6.32] (P = 9.01E-07) and 3.22, 95% CI = [2.06, 5.10] (P = 6.47E-08) in the target and validation cohorts, respectively. The relatively high case/control ORs across PRS quantiles corroborates the presence of strong polygenic components which could be driven by an enrichment of risk alleles within the cases but also by potential enrichment of protective alleles in the old normotensive controls. Moreover, novel pathway-specific PRS revealed an enrichment of the polygenic signal attributable to specific biological pathways. Among those the most significantly associated with hypertension status was the calcium signaling pathway together with other mainly related such as the phosphatidylinositol/inositol phosphate pathways. CONCLUSIONS: The development of pathway-specific PRS could prioritize biological mechanisms, according to their contribution to the genetic susceptibility, whose regulations might be a potential pharmacological preventive target.

Association between Perceived Health-Related Quality of Life and Depression with Frailty in the FRASNET Study.

Frailty is a major challenge facing the aging world. The phenotype of the frail subject is still far from being satisfactorily defined. We report data on mood, cognition, and quality of life (QoL) in relation to anamnestic factors, health, and socio-economic status in the FRASNET geriatric population (1204 subjects in stable health conditions), which is an observational cohort study that includes fairly balanced groups of Italian frail (421, 35%), pre-frail (449, 37.3%) and robust (334, 27.7%) subjects. A conditional inference tree analysis revealed a substantial influence of psychological variables on frailty. The physical indicator of QoL (Short Form Survey-36-Physical Component Summary, SF-36-PCS) was the predominant variable in the full model (threshold at 39.9, p < 0.001): higher frailty was found in subjects with a caregiver and lower SF-36-PCS. Frailty was also associated with the mental indicator of QoL (Short Form Survey-36-Mental Component Summary, SF-36-MCS), depression (Geriatric Depression Scale, GDS-15), leisure activities, and level of education. In support of the prominent role of inflammation in aging and mental illness, the SF-36-PCS score was correlated with the blood concentration of C-X-C motif chemokine ligand 10 (CXCL10) (r Pearson -0.355, p = 0.015), a critical signal in cell senescence and inflammaging, while the rs7567647 variant in FN1 gene encoding a glycoprotein in the extracellular matrix was significantly associated with frailty in a multivariable model (p = 0.0006). The perception of health-related QoL and subclinical depression contribute to frailty. Their assessment could improve the identification of older patients at increased risk of adverse outcomes.

Urinary proteomics reveals key markers of salt sensitivity in hypertensive patients during saline infusion.

BACKGROUND: Hypertension is a complex disease and is the major cause of cardiovascular complications. In the vast majority of individuals, the aetiology of elevated blood pressure (BP) cannot be determined, thus impairing optimized therapies and prognosis for individual patients. A more precise understanding of the molecular pathogenesis of hypertension remains a pressing priority for both basic and translational research. Here we investigated the effect of salt on naive hypertensive patients in order to better understand the salt intake-blood pressure relationship. METHODS: Patients underwent an acute saline infusion and were defined as salt-sensitive or salt-resistant according to mean blood pressure changes. Urinary proteome changes during the salt load test were analysed by a label-free quantitative proteomics approach. RESULTS: Our data show that salt-sensitive patients display equal sodium reabsorption as salt-resistant patients, as major sodium transporters show the same behaviour during the salt load. However, salt-sensitive patients regulate the renin angiotensin system (RAS) differently from salt-resistant patients, and upregulate proteins, as epidermal growth factor (EGF) and plasminogen activator, urokinase (PLAU), involved in the regulation of epithelial sodium channel ENaC activity. CONCLUSIONS: Salt-sensitive and salt-resistant subjects have similar response to a saline/volume infusion as detected by urinary proteome. However, we identified glutamyl aminopeptidase (ENPEP), PLAU, EGF and Xaa-Pro aminopeptidase 2 precursor XPNPEP2 as key molecules of salt-sensitivity, through modulation of ENaC-dependent sodium reabsorption along the distal tubule.

Role of blood pressure dysregulation on kidney and mortality outcomes in COVID-19. Kidney, blood pressure and mortality in SARS-CoV-2 infection.

BACKGROUND: In February 2020 the corona virus disease 2019 (COVID-19) infection started spreading throughout Italy, hitting the Lombardy region very hard. Despite the high diffusion, only a subset of patients developed severe COVID-19: around 25% of them developed acute kidney injury (AKI) and one-third of them died. Elderly patients and patients with high comorbidities were identified as being at higher risk of severe COVID-19. METHODS: Our prospective observational cohort study includes 392 consecutive patients hospitalized for COVID-19 in Milan (median age 67 years, 75% male). We evaluated the relationship between blood pressure at presentation, presence of AKI at Emergency Department admission and during hospitalization, and total in-hospital mortality (24%). RESULTS: Although 58% of our study patients reported a history of hypertension (HYP) (86% on treatment), 30% presented with low blood pressure levels. Only 5.5% were diagnosed with AKI on admission; 75% of hypertensive patients discontinued therapy during hospitalization (only 20% were on treatment at discharge). Gender and hypertension were strongly associated with AKI at admission (odds ratio 11). Blood pressure was inversely correlated with increased risk of AKI upon admission, regardless of the severity of respiratory distress. Age over 65, history of hypertension, and severity of respiratory distress were the main predictors of AKI, which developed in 34.7% of cases during hospitalization. AKI was associated with increased in-hospital mortality. Hypertension and low blood pressure at presentation were the main predictors of in-hospital mortality, together with age over 65, baseline pulmonary involvement, and severity of illness. CONCLUSIONS: In patients hospitalized for COVID-19, hypertension and low blood pressure at presentation are important risk factors for AKI and mortality. Early reduction of antihypertensive therapy may improve outcomes in patients with SARS-CoV-2 infection.

Klotho Gene in Human Salt-Sensitive Hypertension.

BACKGROUND AND OBJECTIVES: Hypertension is a common aging-related disorder. Salt intake is one of the main environmental factors contributing to the development of hypertension. Transgenic mice with one-half Klotho deficiency displayed a spontaneous BP increase and salt-sensitive hypertension in response to high sodium intake. Usually circulating levels of α-Klotho decrease with age, and this reduction may be stronger in patients with several aging-related diseases. This study aimed at exploring the association of Klotho with salt sensitivity in humans. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The role of Klotho polymorphisms and α-Klotho serum levels was evaluated in patients with hypertension who were treatment naive and underwent an acute salt-sensitivity test (discovery n=673, intravenous 2 L of 0.9% saline in 2 hours). Salt sensitivity was defined as a mean BP increase of >4 mm Hg at the end of the infusion. A total of 32 single nucleotide polymorphisms in the Klotho gene (KL), previously identified with a genome-wide association study, were used in the genetic analysis and studied for a pressure-natriuresis relationship. RESULTS: Of the patients with hypertension, 35% were classified as salt sensitive. The most relevant polymorphism associated with pressure natriuresis was the common missense single nucleotide polymorphism rs9536314, and the GG and GT genotypes were more represented among patients who were salt sensitive (P=0.001). Those carrying the G allele showed a less steep pressure-natriuresis relationship, meaning that a significant increase in mean BP was needed to excrete the same quantity of salt compared with patients who were salt resistant. KL rs9536314 also replicated the pressure-natriuresis association in an independent replication cohort (n=193) and in the combined analysis (n=866). There was an inverse relationship between circulating Klotho and mean BP changes after the saline infusion (r=-0.14, P=0.03). Moreover, circulating α-Klotho was directly related to kidney function at baseline eGFR (r=0.22, P<0.001). CONCLUSIONS: KL rs9536314 is associated with salt-sensitive hypertension in patients with hypertension who are treatment naive. Moreover, circulating α-Klotho levels were mainly related to diastolic BP changes at the end of a salt load and to eGFR as an expression of kidney aging.