Serum Uric Acid/Serum Creatinine Ratio and Cardiovascular Mortality in Diabetic Individuals-The Uric Acid Right for Heart Health (URRAH) Project.

Several studies have detected a direct association between serum uric acid (SUA) and cardiovascular (CV) risk. In consideration that SUA largely depends on kidney function, some studies explored the role of the serum creatinine (sCr)-normalized SUA (SUA/sCr) ratio in different settings. Previously, the URRAH (URic acid Right for heArt Health) Study has identified a cut-off value of this index to predict CV mortality at 5.35 Units. Therefore, given that no SUA/sCr ratio threshold for CV risk has been identified for patients with diabetes, we aimed to assess the relationship between this index and CV mortality and to validate this threshold in the URRAH subpopulation with diabetes; the URRAH participants with diabetes were studied (n = 2230). The risk of CV mortality was evaluated by the Kaplan-Meier estimator and Cox multivariate analysis. During a median follow-up of 9.2 years, 380 CV deaths occurred. A non-linear inverse association between baseline SUA/sCr ratio and risk of CV mortality was detected. In the whole sample, SUA/sCr ratio > 5.35 Units was not a significant predictor of CV mortality in diabetic patients. However, after stratification by kidney function, values > 5.35 Units were associated with a significantly higher mortality rate only in normal kidney function, while, in participants with overt kidney dysfunction, values of SUA/sCr ratio > 7.50 Units were associated with higher CV mortality. The SUA/sCr ratio threshold, previously proposed by the URRAH Study Group, is predictive of an increased risk of CV mortality in people with diabetes and preserved kidney function. While, in consideration of the strong association among kidney function, SUA, and CV mortality, a different cut-point was detected for diabetics with impaired kidney function. These data highlight the different predictive roles of SUA (and its interaction with kidney function) in CV risk, pointing out the difference in metabolic- and kidney-dependent SUA levels also in diabetic individuals.

Triglyceride-glucose Index and Mortality in a Large Regional-based Italian Database (Urrah Project).

PURPOSE: Recently, a novel index (triglyceride-glucose index-TyG) was considered a surrogate marker of insulin resistance (IR); in addition, it was estimated to be a better expression of IR than widely used tools. Few and heterogeneous data are available on the relationship between this index and mortality risk in non-Asian populations. Therefore, we estimated the predictive role of baseline TyG on the incidence of all-cause and cardiovascular (CV) mortality in a large sample of the general population. Moreover, in consideration of the well-recognized role of serum uric acid (SUA) on CV risk and the close correlation between SUA and IR, we also evaluated the combined effect of TyG and SUA on mortality risk. METHODS: The analysis included 16,649 participants from the URRAH cohort. The risk of all-cause and CV mortality was evaluated by the Kaplan-Meier estimator and Cox multivariate analysis. RESULTS: During a median follow-up of 144 months, 2569 deaths occurred. We stratified the sample by the optimal cut-off point for all-cause (4.62) and CV mortality (4.53). In the multivariate Cox regression analyses, participants with TyG above cut-off had a significantly higher risk of all-cause and CV mortality, than those with TyG below the cut-off. Moreover, the simultaneous presence of high levels of TyG and SUA was associated with a higher mortality risk than none or only one of the two factors. CONCLUSIONS: The results of this study indicate that these TyG (a low-cost and simple non-invasive marker) thresholds are predictive of an increased risk of mortality in a large and homogeneous general population. In addition, these results show a synergic effect of TyG and SUA on the risk of mortality.

Prognostic Value and Relative Cutoffs of Triglycerides Predicting Cardiovascular Outcome in a Large Regional-Based Italian Database.

BACKGROUND: Despite longstanding epidemiologic data on the association between increased serum triglycerides and cardiovascular events, the exact level at which risk begins to rise is unclear. The Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension has conceived a protocol aimed at searching for the prognostic cutoff value of triglycerides in predicting cardiovascular events in a large regional-based Italian cohort. METHODS AND RESULTS: Among 14 189 subjects aged 18 to 95 years followed-up for 11.2 (5.3-13.2) years, the prognostic cutoff value of triglycerides, able to discriminate combined cardiovascular events, was identified by means of receiver operating characteristic curve. The conventional (150 mg/dL) and the prognostic cutoff values of triglycerides were used as independent predictors in separate multivariable Cox regression models adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, serum uric acid, arterial hypertension, diabetes, chronic renal disease, smoking habit, and use of antihypertensive and lipid-lowering drugs. During 139 375 person-years of follow-up, 1601 participants experienced cardiovascular events. Receiver operating characteristic curve showed that 89 mg/dL (95% CI, 75.8-103.3, sensitivity 76.6, specificity 34.1, P<0.0001) was the prognostic cutoff value for cardiovascular events. Both cutoff values of triglycerides, the conventional and the newly identified, were accepted as multivariate predictors in separate Cox analyses, the hazard ratios being 1.211 (95% CI, 1.063-1.378, P=0.004) and 1.150 (95% CI, 1.021-1.295, P=0.02), respectively. CONCLUSIONS: Lower (89 mg/dL) than conventional (150 mg/dL) prognostic cutoff value of triglycerides for cardiovascular events does exist and is associated with increased cardiovascular risk in an Italian cohort.

Kidney Biopsy and Immuno-Rheumatological Diseases: A Retrospective and Observational Study.

Renal involvement is a common occurrence in patients with immuno-rheumatological diseases (IRDs). Several instances of glomerulonephritis (GN) occur in the setting of IRD and complicate the clinical course of an underlying condition. The aim of this study was to observe the spectrum of nephropathies according to age, kidney function, history of IRD at the time of biopsy, and histopathological kidney diagnosis. We evaluated data relating to 699 consecutive kidney native biopsies (female 52.1%) with a median age of 48 years (IQR 34-62) performed in adult patients collected over 15 years. The study population was divided into three groups: patients with kidney histological findings correlated to underlying IRD (Group 1), patients with kidney histological findings not correlated to underlying IRD (Group 2), and patients with kidney histological findings compatible with "de novo" IRD (absent in personal medical history) (Group 3). Kidney involvement related to IRD was found in 25.2% of patients. Group 1 was mostly represented by lupus nephritis (76.6%), with a younger age than Group 3 (p < 0.001) and by a higher percentage of females than other groups (p < 0.001). Group 3 was the most represented by microscopic polyangiitis (50.8%) when compared with the other two groups (p < 0.001). Acute nephritic syndrome (p < 0.001), acute kidney injury (AKI), and abnormal urinalysis (p < 0.001) were more represented in Group 3 than the other groups. In conclusion, IRDs are characterized by different clinical presentations and heterogeneous histological findings. Kidney biopsy remains fundamental to achieving the correct diagnosis and starting targeted therapy.

Changes in renal microcirculation in patients with nephrotic and nephritic syndrome: The role of resistive index.

BACKGROUND: Renal Resistive Index (RRI) is an important and non-invasive parameter of renal damage and it is associated with abnormal microcirculation or to a parenchymal injury. The aim of our study was to compare the RRI in a cohort of patients with renal diseases categorized in three groups: nephrotic syndrome (NS), acute nephritic syndrome (ANS) and patients with urinary abnormalities (UA). METHODS: Four hundred eighty-two patients with median age of 48 years (IQR 34-62) with indications for kidney disease were included in the study. Biochemical analyses, clinical assessment with detection of NS, ANS and UA and comorbidities were reported. Renal Doppler ultrasound with RRI was evaluated in all patients at the time of enrolment. RESULTS: NS was present in 81 (16.8 %) patients while ANS in 81 (16.8 %) and UA in 228 (47.3 %) patients. Patients with ANS showed significant higher RRI compared to both patients with NS [0.71 (IQR 0.67-0.78) vs 0.68 (0.63-0.73), p < 0.001] and UA [0.71 (0.67-0.78) vs 0.65 (0.61-0.71), p < 0.001]; RRI was higher in NS patients than in patients with UA [0.68 (0.63-0.73) vs 0.65 (0.61-0.71), p < 0.001]. Patients with ANS had significantly lower median estimated glomerular filtration rate (eGFR) compared respectively to NS and UA patients [19.7 ml/min vs 54.8 ml/min and vs 72.3 ml/min, p < 0.001], while renal length was significantly higher in patients with NS compared to both patients with ANS and UA [111.88 mm vs 101.98 mm and vs 106.15, p < 0.001]. Patients with ANS had more frequently hematuria and RRI ≥ 0.70 (p < 0.001) compared to both patients with NS and patients with UA. The multiple regression analysis, weighted for age, showed that RRI inversely correlates with eGFR (ß coefficient = -0.430, p < 0.001). CONCLUSIONS: Higher and pathological RRI were found in ANS than NS and UA. Renal resistive index in ANS reflects changes in intrarenal perfusion and microvascular dysfunction related to disease characteristics.

Novel Genetic Microvascular Dysplasia Causing Hypoperfusion of Cardiac, Renal, and Cerebral Circulation.

BACKGROUND: Microvascular disorders represent an uncommon site of tissue hypo-perfusion and damage. Various genetic and acquired causes can be involved. A 65-year-old man was admitted because of refractory angina, which he had had since the age of 30 years, micro-hematuria, and recurrent transitory ischemic attacks from the age of 64. METHODS: Hematochemical studies, ECG, Holter monitoring, 2D-echo, cardiac magnetic resonance (CMR), CTA of cerebral vessels, endomyocardial coronary angiography, and kidney biopsy processes were undertaken. Gene mutation analysis was conducted using next-generation sequencing, which included more than 5000 genes associated with inherited diseases. RESULTS: Hematochemical findings were unremarkable. The ECG, Holter, 2D-echo, and CTA of brain vessels were normal. Cerebral magnetic resonance showed the presence of multiple small foci of ischemia. Coronary and ventricular angiography showed normal arteries with remarkably slow flow and multiple biventricular micro-aneurysms. At the endomyocardial biopsy, five of seven arterioles presented severe lumen obstruction due to hypertrophy and disarray of the muscular coat. Similarly, obstructed pre-glomerular arteries with glomerular sclerosis were seen at the renal biopsy. Genetics identified mutations in the ABCC6, MMP2, and XYLT1 genes, which play pivotal roles in the extracellular matrix. CONCLUSION: This study described a new genetic microvascular obstructive disease causing progressive hypo-perfusion of the human brain, heart, and kidney.

Resistant Hypertension and Related Outcomes in a Cohort of Patients with Cardiorenal Multimorbidity Hospitalized in an Internal Medicine Ward.

INTRODUCTION: Resistant hypertension (RH) is characterized by the failure to reach a goal blood pressure despite the administration of three medications at maximally tolerated doses, one of which being a diuretic. RH can be observed in a variety of clinical conditions, such as heart failure and reduced renal function and may confer high cardiovascular risk. AIM: To evaluate the prevalence of RH and its association with clinical outcomes; the primary outcome was in-hospital mortality and the composite outcome was all-cause of mortality and morbidity in a cohort of patients with cardiorenal multimorbidity hospitalized in an internal medicine ward. METHODS: We conducted a retrospective analysis of consecutive hypertensive patients with cardiorenal multimorbidity. The composite outcome incorporated all-cause of in-hospital mortality and occurrence of sepsis, pulmonary embolism, acute coronary syndrome, stroke and renal replacement therapy. RESULTS: We collected data in 141 inpatients with a mean age of 77 years ± 10 (males 65.9 %), estimated glomerular filtration rate of 34 ± 18.6 ml/min with length of stay of 17 ± 12 days. The prevalence of RH was 52.4%. In-hospital mortality was observed in 24 patients (17%) and the composite outcome occurred in 87 patients (61.7%) and among these 74 (85.1%) were patients with RH. Free survival for composite outcome was significantly higher in patients without RH than patients with RH (log rank 7.52, p = 0.006). Resistant hypertension was a risk factor for composite outcome [HR 1.857(C.I. 1.170-2.946, p = 0.009)]. CONCLUSION: In patients with cardiorenal multimorbidity there is a high proportion of RH that represents a risk factor for composite outcome but not for in-hospital mortality.

The Results of the URRAH (Uric Acid Right for Heart Health) Project: A Focus on Hyperuricemia in Relation to Cardiovascular and Kidney Disease and its Role in Metabolic Dysregulation.

The relationship between Serum Uric Acid (UA) and Cardiovascular (CV) diseases has already been extensively evaluated, and it was found to be an independent predictor of all-cause and cardiovascular mortality but also acute coronary syndrome, stroke and heart failure. Similarly, also many papers have been published on the association between UA and kidney function, while less is known on the role of UA in metabolic derangement and, particularly, in metabolic syndrome. Despite the substantial number of publications on the topic, there are still some elements of doubt: (1) the better cut-off to be used to refine CV risk (also called CV cut-off); (2) the needing for a correction of UA values for kidney function; and (3) the better definition of its role in metabolic syndrome: is UA simply a marker, a bystander or a key pathological element of metabolic dysregulation?. The Uric acid Right for heArt Health (URRAH) project was designed by the Working Group on uric acid and CV risk of the Italian Society of Hypertension to answer the first question. After the first papers that individuates specific cut-off for different CV disease, subsequent articles have been published responding to the other relevant questions. This review will summarise most of the results obtained so far from the URRAH research project.

Contrast-Induced Acute Kidney Injury and Endothelial Dysfunction: The Role of Vascular and Biochemical Parameters.

INTRODUCTION: Contrast-induced acute kidney injury (CIAKI) is one of the main causes of acute renal failure in hospitalized patients, following the administration of iodinated contrast medium used for CT scans and angiographic procedures. CIAKI determines a high cardiovascular risk and appears to be one of the most feared complications of coronary angiography, causing a notable worsening of the prognosis with high morbidity and mortality. AIM: To evaluate a possible association between the renal resistive index (RRI) and the development of CIAKI, as well as an association with the main subclinical markers of atherosclerosis and the main cardiovascular risk factors. MATERIALS AND METHODS: We enrolled 101 patients with an indication for coronary angiography. Patients underwent an assessment of renal function (serum nitrogen and basal creatinine, 48 and 72 h after administration of contrast medium), inflammation (C reactive protein (CRP), serum calcium and phosphorus, intact parathormone (iPTH), 25-hydroxyvitaminD (25-OH-VitD), serum uric acid (SUA), total cholesterol, serum triglycerides, serum glucose and insulin). All patients also carried out an evaluation of RRI, intima-media thickness (IMT), interventricular septum (IVS) and the ankle-brachial index (ABI). RESULTS: 101 patients (68 male), with a mean age of 73.0 ± 15.0 years, were enrolled for the study; 35 are affected by type 2 diabetes mellitus. A total of 19 cases of CIAKI were reported (19%), while among diabetic patients we reported an incidence of 23% (8 patients). In our study, patients with CIAKI had significantly higher RRI (p < 0.001) and IMT (p < 0.001) with respect to the patients who did not develop CIAKI. Furthermore, patients with CIAKI had significantly higher CRP (p < 0.001) and SUA (p < 0.006). CONCLUSIONS: We showed a significant difference in RRI, IMT, SUA and CRP values between the population developing CIAKI and patients without CIAKI. This data appears relevant considering that RRI and IMT are low-cost, non-invasive and easily reproducible markers of endothelial dysfunction and atherosclerosis.

Parasympathetic activity and total fibrotic kidney in autosomal-dominant polycystic kidney disease patients: a pilot study.

PURPOSE: Renin-angiotensin system hyperactivation in autosomal-dominant polycystic kidney disease (ADPKD) patients leads to early hypertension. Cystic enlargement probably causes parenchymal hypoxia, renin secretion, and endothelial dysfunction. Sympathetic and parasympathetic balance is altered in this condition, especially during the night, also affecting blood pressure circadian rhythm. Aim of this study was to evaluate sympathetic/parasympathetic balance using heart rate variability (HRV) parameters and find a correlation between HRV and renal damage progression, as total kidney volume enlargement, in ADPKD patients. METHODS: Sixteen adult ADPKD patients were enrolled in the study. Eleven patients (68.8%) were male, and the median age was 42 years (IQR 36-47.5). HRV parameters were calculated using 24 h-ECG Holter. A kidney magnetic resonance imaging (MRI) scan 3 Tesla was performed to evaluate total kidney volume (TKV) and total fibrotic volume (TFV). RESULTS: A statistically significant positive linear correlation was observed between length of kidneys and frequency domain parameters as low frequency (LF) (r = 0.595, p < 0.05) and LFday (r = 0.587, p < 0.05). Moreover, a statistically significant positive linear correlation exists between high frequency (HF) and TFV (r = 0.804, p < 0.01) or height-adjusted (ha) TFV (r = 0.801, p < 0.01). Finally, we found a statistically significant positive linear correlation between HFnight and TKV (r = 0.608, p < 0.05), ha-TKV (r = 0.685, p < 0.01), TFV (r = 0.594, p < 0.05), and ha-TFV (r = 0.615, p < 0.05). CONCLUSION: We suppose that the increase in TKV and TFV could lead to a parasympathetic tone hyperactivation, probably in response to hypoxic stress and vasoconstriction due to cystic enlargement.

Stem Cells in Kidney Ischemia: From Inflammation and Fibrosis to Renal Tissue Regeneration.

Ischemic nephropathy consists of progressive renal function loss due to renal hypoxia, inflammation, microvascular rarefaction, and fibrosis. We provide a literature review focused on kidney hypoperfusion-dependent inflammation and its influence on renal tissue's ability to self-regenerate. Moreover, an overview of the advances in regenerative therapy with mesenchymal stem cell (MSC) infusion is provided. Based on our search, we can point out the following conclusions: 1. endovascular reperfusion is the gold-standard therapy for RAS, but its success mostly depends on treatment timeliness and a preserved downstream vascular bed; 2. anti-RAAS drugs, SGLT2 inhibitors, and/or anti-endothelin agents are especially recommended for patients with renal ischemia who are not eligible for endovascular reperfusion for slowing renal damage progression; 3. TGF-ß, MCP-1, VEGF, and NGAL assays, along with BOLD MRI, should be extended in clinical practice and applied to a pre- and post-revascularization protocols; 4. MSC infusion appears effective in renal regeneration and could represent a revolutionary treatment for patients with fibrotic evolution of renal ischemia.

Serum Uric Acid Predicts All-Cause and Cardiovascular Mortality Independently of Hypertriglyceridemia in Cardiometabolic Patients without Established CV Disease: A Sub-Analysis of the URic acid Right for heArt Health (URRAH) Study.

High serum uric acid (SUA) and triglyceride (TG) levels might promote high-cardiovascular risk phenotypes across the cardiometabolic spectrum. However, SUA predictive power in the presence of normal and high TG levels has never been investigated. We included 8124 patients from the URic acid Right for heArt Health (URRAH) study cohort who were followed for over 20 years and had no established cardiovascular disease or uncontrolled metabolic disease. All-cause mortality (ACM) and cardiovascular mortality (CVM) were explored by the Kaplan-Meier estimator and Cox multivariable regression, adopting recently defined SUA cut-offs for ACM (≥4.7 mg/dL) and CVM (≥5.6 mg/dL). Exploratory analysis across cardiometabolic subgroups and a sensitivity analysis using SUA/serum creatinine were performed as validation. SUA predicted ACM (HR 1.25 [1.12-1.40], p < 0.001) and CVM (1.31 [1.11-1.74], p < 0.001) in the whole study population, and according to TG strata: ACM in normotriglyceridemia (HR 1.26 [1.12-1.43], p < 0.001) and hypertriglyceridemia (1.31 [1.02-1.68], p = 0.033), and CVM in normotriglyceridemia (HR 1.46 [1.23-1.73], p < 0.001) and hypertriglyceridemia (HR 1.31 [0.99-1.64], p = 0.060). Exploratory and sensitivity analyses confirmed our findings, suggesting a substantial role of SUA in normotriglyceridemia and hypertriglyceridemia. In conclusion, we report that SUA can predict ACM and CVM in cardiometabolic patients without established cardiovascular disease, independent of TG levels.

Renal Stem Cells, Renal Resistive Index, and Neutrophil Gelatinase Associated Lipocalin Changes After Revascularization in Patients With Renovascular Hypertension and Ischemic Nephropathy.

BACKGROUND: Percutaneous transluminal renal angioplasty (PTRA) with or without stenting is the gold standard therapy in patients with atherosclerotic renal artery stenosis (aRAS). However, therapeutic success depends on the correct timing of revascularization and the reversibility of the renal damage. MATERIALS AND METHODS: We report a case series of patients treated with PTRA for renovascular hypertension and ischemic nephropathy. We measured bilateral renal resistive index (RRI), circulating renal stem cells (RSC), and Neutrophil Gelatinase Associated Lipocalin (NGAL) at baseline and after PTRA at different time points to understand their changes in post-revascularization. RESULTS: At baseline, the studied patients (n = 5) had different RSC levels. After PTRAs, all patients showed an improvement in blood pressure, while renal function varied differently within the studied subjects. RRI > 0.75 at baseline and the absence of NGAL decrease after PTRAs were associated with post-PTRA renal function worsening, despite an increase of RSC in all patients. CONCLUSION: Although limited to a few patients, our observation allowed the exploration of the behaviour of the studied parameters in different degrees of renal ischemia. This revealed different disease models suggesting the importance of further investigations in larger and homogeneous cohorts to confirm that a greater basal RSC percentage, low RRI values before PTRA, and a post-revascularization NGAL reduction could be related to better renal outcomes in aRAS patients.

Nephroangiosclerosis not related to hypertension: A matter to resolve in the era of precision medicine.

Nephroangiosclerosis (NAS) associated with hypertension continues to be one of the most causes of end stage renal diseases in Europe, but it is still poorly studied. The prevalence of NAS shows a large variability due to the difference among different countries regarding clinical presentations and the indication to perform renal biopsy. The study aimed to investigate the prevalence in biopsy-proven NAS patients and the association with hypertension and/or glomerulonephritis (GN). We included all patients referred for native kidney biopsy between 2003-2021 at Policlinic Umberto I of Rome. From 837 patients who underwent renal biopsy NAS was diagnosed in 80 (10.5%) patients. Serum creatinine was significantly higher in NAS [2.07 mg/dl (IQR 1.13-5.2) vs 1.1 mg/dl (IQR 0.8-2.1), p < 0.001] compared to patients without NAS. Hypertension was present in 45% of patients with NAS. Proteinuria was significantly higher in patients with mild-moderate NAS compared to patients with severe NAS [2.6 g/die (IQR 1-5) vs 1.5 g/die (IQR 0.86-2.3), p < 0.05]. We did not find any significant differences, including histological features, between NAS patients with hypertension and NAS patients without hypertension (p > 0.05). IgA nephropathy, focal segmental glomerulosclerosis and membranous nephropathy were the most frequent GN associated. In conclusion no specific histological features are reported in NAS with and without hypertension. More information on the phenotype, clinical presentation and markers are needed to improve histological and clinical diagnostics.

The risks associated with percutaneous native kidney biopsies: a prospective study.

BACKGROUND: The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy. METHODS: The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression. RESULTS: Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08-1.17], liver disease (OR 2.27, 95% CI 1.21-4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07-1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92-0.99) were protective. CONCLUSIONS: This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

Sonographic evaluation of hypertension: Role of atrophic index and renal resistive index.

Hypertension can cause structural and functional renal damage. Intrarenal ultrasound parameters have been extensively investigated in hypertensive patients and among the parameters introduced, the renal resistive index (RI) is associated with the progression of chronic kidney disease and hypertension. Atrophic index (AI) is an indirect anatomical ultrasound index that reports the atrophic changes of the renal parenchyma and it is mainly studied in chronic glomerular diseases. The present study aimed to evaluate renal RI and AI in hypertensive patients with normal renal function. AI showed correlations with all parameters associated with renal function reduction (age, creatinine, and intrarenal arterial stiffness). AI, in combination with RI, can represent in hypertensive patients an additional marker for renal damage progression.

Assessment of renal microcirculation in biopsy-proven tubulointerstitial nephritis in patients with and without glomerular disease: the role of resistive index.

BACKGROUND: Renal resistive index (RRI) measured by Doppler sonography is a marker of microvascular status and it is associated with changes in renal function. Aim of the study was to assess RRI in biopsy-proven tubulointerstitial nephritis (TIN) in patients with and without glomerular disease. METHODS: 132 consecutive patients underwent to native renal biopsy with diagnosis of isolated TIN or in association with glomerulonephritis. Estimated glomerular filtration rate (eGFR), 24-hour urinary protein excretion and renal ecocolorDoppler ultrasonography with RRI assessment were performed at time of enrollment. RESULTS: Patients with isolated-TIN had significantly higher RRI than both patients with non-immunoglobulin A glomerulonephritis (non-IgA-TIN) [0.73 (0.68-0.77) vs 0.64 (0.60-0.67), p < 0.001] and patients with IgA nephropathy (IgAN) [0.73 (0.68-0.77) vs 0.66 (0.60-0.71), p < 0.01]. Patients with isolated-TIN had mainly RRI ≥ 0.70 (n = 15, 65.2%) with the respect to patients with non-IgA-TIN (n = 7, 12.3%) and patients with IgAN (n = 17, 32.7%). A negative linear correlation was found between RRI and hemoglobin (r = 0.233, p < 0.01) and between RRI and eGFR (r = 0.537, p < 0.001). CONCLUSION: Tubulointerstitial damage is the most accurate histological lesion that correlates with eGFR and renal impairment. RRI can be a useful parameter to detect tubulointerstitial lesions.

Serum uric acid levels threshold for mortality in diabetic individuals: The URic acid Right for heArt Health (URRAH) project.

BACKGROUND AND AIM: The URRAH (URic acid Right for heArt Health) Study has identified cut-off values of serum uric acid (SUA) predictive of total mortality at 4.7 mg/dl, and cardiovascular (CV) mortality at 5.6 mg/dl. Our aim was to validate these SUA thresholds in people with diabetes. METHODS AND RESULTS: The URRAH subpopulation of people with diabetes was studied. All-cause and CV deaths were evaluated at the end of follow-up. A total of 2570 diabetic subjects were studied. During a median follow-up of 107 months, 744 deaths occurred. In the multivariate Cox regression analyses adjusted for several confounders, subjects with SUA ≥5.6 mg/dl had higher risk of total (HR: 1.23, 95%CI: 1.04-1.47) and CV mortality (HR:1.31, 95%CI:1.03-1.66), than those with SUA <5.6 mg/dl. Increased all-cause mortality risk was shown in participants with SUA ≥4.7 mg/dl vs SUA below 4.7 mg/dl, but not statistically significant after adjustment for all confounders. CONCLUSIONS: SUA thresholds previously proposed by the URRAH study group are predictive of total and CV mortality also in people with diabetes. The threshold of 5.6 mg/dl can predict both total and CV mortality, and so is candidate to be a clinical cut-off for the definition of hyperuricemia in patients with diabetes.