Effect of Delayed Surgery for Ventricular Septal Rupture on Postoperative Outcomes.

OBJECTIVES: The prognosis of ventricular septal rupture (VSR) after acute myocardial infarction remains poor; hence, surgical repair is essential. However, the appropriate timing for surgical intervention remains unclear. We aimed to compare the prognosis between early (<96 hours) and delayed (≥96 hours) surgery for VSR. METHODS: This single-center, retrospective cohort study used data from 49 patients who underwent VSR repair after acute myocardial infarction (AMI) between 2007 and 2022 at our institution. In-hospital and one-, three-, and 10-year mortality and major adverse cardiac and cerebrovascular events were compared between the early (group A) and delayed (group B) surgery after AMI. RESULTS: No significant differences were found between the patients' backgrounds of the two groups. The in-hospital mortality rates were 37.5 and 16.0% for groups A and B, respectively (P = 0.114). The overall survival rates estimated using Kaplan-Meier analysis were 66.5 ± 6.9, 58.2 ± 7.5, and 28.8 ± 10.6% after one, three, and 10 years, respectively. The mortality rates in group B at three (hazard risk ratio: 2.691; 95% confidence interval: 1.02-7.097) and 10 (hazard risk ratio: 2.575; 95% confidence interval: 1.125-5.891) years were significantly better than those in group A. Major adverse cardiac and cerebrovascular events were significantly different between the two groups at all time points. CONCLUSIONS: These results showed that patients who underwent surgery for VSR 96 hours after AMI had better long-term survival than those who underwent surgery within 96 hours.

Prediction for Risk of Hypouricemia in Hospitalized Patients: A Single-center, Retrospective Cohort Study.

Background Hypouricemia, defined as a serum uric acid (SUA) level ≤2 mg/dL, could be a risk factor for death in hospitalized patients. However, how explanatory variables can explain hypouricemia as an objective variable in a logistic regression analysis remains unknown. Purpose To predict the risk factors for hypouricemia in hospitalized patients using a robust Bayesian logistic (RBL) model. Methods This study retrospectively enrolled patients who visited Yonago Medical Center between April 2020 and March 2021. The association between potential risk factors and hypouricemia was analyzed using the RBL model in Python-modulated PyMC3. The final model was selected based on the lowest Watanabe-Akaike information criterion (WAIC). Results Of the 618 patients, 64 (10.4%) had hypouricemia. Based on the model according to the lowest WAIC, independent risk factors for hypouricemia were febuxostat [odds ratio (OR) 5.46, 95% confidence interval (CI) 2.32-13.4], amino acids in parenteral nutrition (OR 5.19, 95% CI 1.62-15.1), TMP-SMX (OR 4.20, 95% CI 1.66-10.9), emaciation (OR 3.48, 95% CI 1.75-7.21), and serum sodium level (OR 0.90, 95% CI 0.84-0.96). Conclusion The RBL model predicted amino acids in parenteral nutrition, TMP-SMX, emaciation, and low serum sodium levels for hypouricemia, in addition to the authentic risk factor febuxostat.

Coronary artery complications in patients with Kawasaki disease who successfully responded to the standard initial IVIG treatment.

OBJECTIVES: To identify clinical characteristics of patients with non-refractory Kawasaki disease (KD), which were defined as those who successfully responded to the standard initial intravenous immunoglobulin (IVIG) treatment (2 g/kg/day, single infusion) without any secondary or later additional specific treatments, and to investigate the factors associated with the development of coronary artery (CA) complications in patients with non-refractory KD. DESIGN: Retrospective cohort study. SETTING: Hospitals specialising in paediatrics and hospitals with ≥100 beds and a paediatric department throughout Japan. PATIENTS: A total of 122 489 patients who developed KD across Japan during 2011-2018. MAIN OUTCOME MEASURES: CA abnormalities identified after acute illness of KD (defined as CA sequelae). RESULTS: A total of 69 735 patients with non-refractory KD were identified, of which 672 (0.96%) experienced CA sequelae. Among patients with non-refractory KD, the presence of CA abnormalities identified at initial echocardiographic assessment was strongly associated with CA sequelae (adjusted OR (95% CI): 37.8 (31.9 to 44.7)). CA sequelae was also associated with male patients, infants (<12 months old), older patients (≥60 months old) and patients who received delayed initial IVIG treatment (>7 days from KD onset). Subgroup analyses demonstrated that delayed initial IVIG treatment was significantly associated with the development of CA sequelae in both patients with and without CA abnormalities identified at initial echocardiographic assessment. CONCLUSIONS: Approximately 1% of patients with non-refractory KD may develop CA sequelae. Our findings highlight the importance of initial echocardiographic assessment and early initiation of IVIG treatments for patients with KD.

Activation of AMPD2 drives metabolic dysregulation and liver disease in mice with hereditary fructose intolerance.

Hereditary fructose intolerance (HFI) is a painful and potentially lethal genetic disease caused by a mutation in aldolase B resulting in accumulation of fructose-1-phosphate (F1P). No cure exists for HFI and treatment is limited to avoid exposure to fructose and sugar. Using aldolase B deficient mice, here we identify a yet unrecognized metabolic event activated in HFI and associated with the progression of the disease. Besides the accumulation of F1P, here we show that the activation of the purine degradation pathway is a common feature in aldolase B deficient mice exposed to fructose. The purine degradation pathway is a metabolic route initiated by adenosine monophosphate deaminase 2 (AMPD2) that regulates overall energy balance. We demonstrate that very low amounts of fructose are sufficient to activate AMPD2 in these mice via a phosphate trap. While blocking AMPD2 do not impact F1P accumulation and the risk of hypoglycemia, its deletion in hepatocytes markedly improves the metabolic dysregulation induced by fructose and corrects fat and glycogen storage while significantly increasing the voluntary tolerance of these mice to fructose. In summary, we provide evidence for a critical pathway activated in HFI that could be targeted to improve the metabolic consequences associated with fructose consumption.

Clinical characteristics and impact of pseudo-lumen blood flow on long-term vessel dilatation in spontaneous isolated dissection of superior mesenteric/celiac artery.

This study aimed to identify the clinical characteristics associated with spontaneous isolated dissection of superior mesenteric artery/celiac artery (SIDSMA/SIDCA). This observational study, conducted at Toranomon Hospital, Japan between 2009 and 2020, analyzed consecutive SIDSMA/SIDCA cases based on radiology data. The study compared clinical characteristics between symptomatic and asymptomatic patients with SIDSMA/SIDCA and investigated factors related to future vessel dilatation. Among 57 cases (44 SIDSMA, 17 SIDCA, and 4 both), the majority were male (87.7%), nearly half having hypertension (43.9%) and smokers (48.9%). Of those, 17 cases (29.8%) were symptomatic; abdominal pain (94.1%), back pain (23.5%), nausea (17.6%) and fever (5.9%). The symptomatic group was younger (52.6 ± 9.4 versus 67.2 ± 7.9 years, P < 0.001), had higher systolic and mean blood pressure (142.6 ± 20.0 versus 129.5 ± 16.5 mmHg, P = 0.017; 96.1 ± 14.6 versus 88.2 ± 17.7 mmHg, P = 0.038), a higher white blood cell count (9975 ± 5032 versus 6268 ± 1991 /µL, P = 0.012), and a higher LDL cholesterol level at diagnosis (129.7 ± 21.7 versus 87.2 ± 25.6 mg/dL, P = 0.002) than the asymptomatic group. The factors associated with future vessel dilatation included the presence of pseudo-lumen flow in the dissection vessel (73.9% versus 41.4%, p = 0.019) and a larger vessel diameter (13.5 ± 2.4 mm versus 11.5 ± 2.1 mm, p = 0.005) at diagnosis after multiple adjustments, pseudo-lumen flow was a predictor of future vessel dilatation (odds ratio, 4.80; 95% confidence interval, 1.11-20.75; p = 0.036). The study revealed that only 30% of SIDSMA/SIDCA cases were symptomatic. Symptomatic cases were generally younger and exhibited higher blood pressure and elevated white blood cell counts. These findings offer valuable insights for the acute diagnosis of SIDSMA/SIDCA.

Association between parental decisions regarding abortion and severity of fetal heart disease.

The prenatal diagnosis of fetal heart disease potentially influences parental decision-making regarding pregnancy termination. Existing literature indicates that the severity, whether in complexity or lethality, significantly influences parental decisions concerning abortion. However, questions remain as to how fetal heart disease severity impacts parental decisions, given recent advancements in postsurgical outcomes. Therefore, we investigated risk factors associated with parents' decision-making regarding abortion following a prenatal diagnosis of fetal heart disease. Our analysis included 73 (terminated: n = 37; continued: n = 36) pregnancies with a fetal heart disease diagnosed before 22 weeks of gestation. Increased gestational age at diagnosis reduced the likelihood of parents' decision on termination (Model 1: adjusted odds ratio, 0.94; 95% confidence interval 0.89-0.99; Model 2: 0.95 0.90-0.997). Critical disease (5.25; 1.09-25.19) and concurrent extracardiac or genetic abnormalities (Model 1: 4.19, 1.21-14.53; Model 2: 5.47, 1.50-19.96) increased the likelihood of choosing abortion. Notably, complex disease did not significantly influence parental decisions (0.56; 0.14-2.20). These results suggest that parental decision-making regarding abortion may be influenced by earlier gestational age at diagnosis, the lethality of heart disease, and extracardiac or genetic abnormalities, but not its complexity if prenatal diagnosis and parental counseling are provided at a cardiovascular-specialized facility.

Impact of a national initiative to provide civilian cardiopulmonary resuscitation training courses on the rates of bystander intervention by citizens and survival after out-of-hospital cardiac arrest.

BACKGROUND: The impact of a national initiative to provide cardiopulmonary resuscitation (CPR) education to the public on the rates of citizen-initiated CPR and survival following out-of-hospital cardiac arrest (OHCA) remains uncertain. METHODS: We examined 358,025 cases of citizen-witnessed OHCA with presumed cardiac origin, recorded in the Japanese nationwide registry from 2005 to 2020. We assessed the relationship between the number of individuals certified in CPR courses, citizen interventions, and neurologically favorable survival at one month. RESULTS: The cumulative number of certified citizens has linearly increased from 9,930,327 in 2005 to 34,938,322 in 2020 (incidence rate ratio for annual number = 1.03, p < 0.001), encompassing 32.3% of the Japanese population aged 15 and above. Similarly, the prevalence of citizen-initiated CPR has consistently increased from 40.6% in 2005 to 56.8% in 2020 (P for trend < 0.001). Greater citizen CPR engagement was significantly associated with better outcome in initial shockable rhythm patients [chest compression only: odds ratio (OR) 1.24; 95% confidence interval (CI) 1.02-1.51; P = 0.029; chest compression with rescue breathing: OR 1.33; 95% CI 1.08-1.62; P = 0.006; defibrillation with chest compression: OR 2.27; 95% CI 1.83-2.83; P < 0.001; defibrillation with chest compression and rescue breathing: OR 2.15; 95% CI 1.70-2.73; P < 0.001 vs. no citizen CPR]. CONCLUSIONS: The incidence of citizen-initiated CPR across Japan has consistently and proportionately increased with the rising number of individuals certified in CPR courses. Greater citizen CPR involvement has been linked to neurologically favorable survival, particularly in cases with an initial shockable rhythm.

Higher Cholesterol Absorption Marker at Baseline Predicts Fewer Cardiovascular Events in Elderly Patients Receiving Hypercholesterolemia Treatment: The KEEP Study.

BACKGROUND: Higher cholesterol absorption has been reported to be related to a higher incidence of cardiovascular events (CVEs). The KEEP (Kyushu Elderly Ezetimibe Phytosterol) study, a substudy of the EWTOPIA 75 (Ezetimibe Lipid-Lowering Trial on Prevention of Atherosclerotic Cardiovascular Disease in 75 or Older) study, investigated the relationships of cholesterol absorption and synthesis markers with CVEs in older old individuals with hypercholesterolemia, particularly in relation to ezetimibe treatment. METHODS AND RESULTS: Eligible patients were those aged ≥75 years who had low-density lipoprotein cholesterol ≥140 mg/dL, no history of coronary artery disease, and no recent use of lipid-lowering drugs. Participants were randomly assigned into a diet-only or diet-plus-ezetimibe group. Baseline and 24-week follow-up blood samples were analyzed for cholesterol absorption (eg, campesterol) and synthesis markers (eg, lathosterol). Of 1287 patients, 1061 patients with baseline measurement were analyzed. Over a median follow-up of 4.0 years, 64 CVEs occurred. Higher campesterol levels at baseline were significantly associated with a lower risk of CVEs. After adjustment for sex, age, and treatment, the hazard ratios for the lowest to highest quartile categories of baseline campesterol were 1.00 (reference), 0.59 (95% CI, 0.30-1.17), 0.44 (95% CI, 0.21-0.94), and 0.44 (95% CI, 0.21-0.93), respectively (trend P=0.01). This association persisted after further adjustment for hypertension, diabetes, and other cardiovascular risk factors. Neither interactions with ezetimibe treatment nor mediating effects of the changes in cholesterol absorption markers were observed. CONCLUSIONS: The KEEP study indicated that higher campesterol levels without lipid-lowering drugs were associated with a lower incidence of CVEs in older old individuals with hypercholesterolemia who were subsequently treated with diet or ezetimibe. REGISTRATION: URL: https://www.umin.ac.jp; unique identifier: UMIN000017769.

World Heart Federation Roadmap for Secondary Prevention of Cardiovascular Disease: 2023 Update.

Background: Secondary prevention lifestyle and pharmacological treatment of atherosclerotic cardiovascular disease (ASCVD) reduce a high proportion of recurrent events and mortality. However, significant gaps exist between guideline recommendations and usual clinical practice. Objectives: Describe the state of the art, the roadblocks, and successful strategies to overcome them in ASCVD secondary prevention management. Methods: A writing group reviewed guidelines and research papers and received inputs from an international committee composed of cardiovascular prevention and health systems experts about the article's structure, content, and draft. Finally, an external expert group reviewed the paper. Results: Smoking cessation, physical activity, diet and weight management, antiplatelets, statins, beta-blockers, renin-angiotensin-aldosterone system inhibitors, and cardiac rehabilitation reduce events and mortality. Potential roadblocks may occur at the individual, healthcare provider, and health system levels and include lack of access to healthcare and medicines, clinical inertia, lack of primary care infrastructure or built environments that support preventive cardiovascular health behaviours. Possible solutions include improving health literacy, self-management strategies, national policies to improve lifestyle and access to secondary prevention medication (including fix-dose combination therapy), implementing rehabilitation programs, and incorporating digital health interventions. Digital tools are being examined in a range of settings from enhancing self-management, risk factor control, and cardiac rehab. Conclusions: Effective strategies for secondary prevention management exist, but there are barriers to their implementation. WHF roadmaps can facilitate the development of a strategic plan to identify and implement local and national level approaches for improving secondary prevention.

2023 update and perspectives.

Total 276 manuscripts were published in Hypertension Research in 2022. Here our editorial members picked up the excellent papers, summarized the current topics from the published papers and discussed future perspectives in the sixteen fields. We hope you enjoy our special feature, 2023 update and perspectives in Hypertension Research.

Japanese Clinical Practice Guidelines for Rehabilitation in Critically Ill Patients 2023 (J-ReCIP 2023).

Providing standardized, high-quality rehabilitation for critically ill patients is a crucial issue. In 2017, the Japanese Society of Intensive Care Medicine (JSICM) promulgated the "Evidence-Based Expert Consensus for Early Rehabilitation in the Intensive Care Unit" to advocate for the early initiation of rehabilitations in Japanese intensive care settings. Building upon this seminal work, JSICM has recently conducted a rigorous systematic review utilizing the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. This endeavor resulted in the formulation of Clinical Practice Guidelines (CPGs), designed to elucidate best practices in early ICU rehabilitation. The primary objective of this guideline is to augment clinical understanding and thereby facilitate evidence-based decision-making, ultimately contributing to the enhancement of patient outcomes in critical care settings. No previous CPGs in the world has focused specifically on rehabilitation of critically ill patients, using the GRADE approach. Multidisciplinary collaboration is extremely important in rehabilitation. Thus, the CPGs were developed by 73 members of a Guideline Development Group consisting of a working group, a systematic review group, and an academic guideline promotion group, with the Committee for the Clinical Practice Guidelines of Early Mobilization and Rehabilitation in Intensive Care of the JSICM at its core. Many members contributed to the development of the guideline, including physicians and healthcare professionals with multiple and diverse specialties, as well as a person who had been patients in ICU. Based on discussions among the group members, eight important clinical areas of focus for this CPG were identified. Fourteen important clinical questions (CQs) were then developed for each area. The public was invited to comment twice, and the answers to the CQs were presented in the form of 10 GRADE recommendations and commentary on the four background questions. In addition, information for each CQ has been created as a visual clinical flow to ensure that the positioning of each CQ can be easily understood. We hope that the CPGs will be a useful tool in the rehabilitation of critically ill patients for multiple professions.

Comparison of Recommendations Made by Committee Members with and without Financial Conflict of Interest on Japanese Guideline of Treatment of Hyperuricemia and Gout, Third Edition.

Clinical practice guidelines (CPGs) consist of clinical questions (CQs) and corresponding recommendations. Considering the estimation of body of evidence, patients' opinions, and medical economics, recommendations can vary depending on the votes of the committee members of CPGs. Taking this into consideration, concerns have already been raised on how financial conflict of interest (COI) potentially influences recommendations. In this study, we developed the third edition of guideline for the management of hyperuricemia and gout. This CPG was composed of seven CQs and recommendations. The direction and strength of the recommendations were determined by votes. There are three CQs. Individual questions asked whether uric acid-lowering-agents (ULAs) could be applied to hyperuricemic patients with chronic kidney disease (CKD) (CQ A), hypertension (CQ B), or heart failure (CQ C) to prevent organ damage. We examined whether the absence (18 members) or presence (8 members) of COIs of committee members could influence the votes. In total, 26 committee members with and without COI have equally determined the direction and strength of recommendations. In CQ A, members without financial COIs and those with financial COI selected conditional recommendation for the use of ULAs in patients with CKD (without COI, 17/18; with COI, 7/8). In CQ B, members without financial COIs and those with financial COI selected conditional recommendation against the use of ULAs in hypertensive patients (without COI, 14/18; with COI, 5/8). In CQ C, members without financial COIs and those with financial COIs have selected conditional recommendation against the use of ULAs in patients suffering from heart failure (without COI, 15/18; with COI, 4/8). We found that members with financial COIs have determined their recommendations in the same direction and strength as those without financial COIs.

Exploring the Multifaceted Nexus of Uric Acid and Health: A Review of Recent Studies on Diverse Diseases.

The prevalence of patients with hyperuricemia or gout is increasing worldwide. Hyperuricemia and gout are primarily attributed to genetic factors, along with lifestyle factors like consuming a purine-rich diet, alcohol and/or fructose intake, and physical activity. While numerous studies have reported various comorbidities linked to hyperuricemia or gout, the range of these associations is extensive. This review article focuses on the relationship between uric acid and thirteen specific domains: transporters, genetic factors, diet, lifestyle, gout, diabetes mellitus, metabolic syndrome, atherosclerosis, hypertension, kidney diseases, cardiovascular diseases, neurological diseases, and malignancies. The present article provides a comprehensive review of recent developments in these areas, compiled by experts from the Young Committee of the Japanese Society of Gout and Uric and Nucleic Acids. The consolidated summary serves to enhance the global comprehension of uric acid-related matters.

Endogenous Fructose Production and Metabolism Drive Metabolic Dysregulation and Liver Disease in Mice with Hereditary Fructose Intolerance.

Excessive intake of sugar, and particularly fructose, is closely associated with the development and progression of metabolic syndrome in humans and animal models. However, genetic disorders in fructose metabolism have very different consequences. While the deficiency of fructokinase, the first enzyme involved in fructose metabolism, is benign and somewhat desirable, missense mutations in the second enzyme, aldolase B, causes a very dramatic and sometimes lethal condition known as hereditary fructose intolerance (HFI). To date, there is no cure for HFI, and treatment is limited to avoiding fructose and sugar. Because of this, for subjects with HFI, glucose is their sole source of carbohydrates in the diet. However, clinical symptoms still occur, suggesting that either low amounts of fructose are still being consumed or, alternatively, fructose is being produced endogenously in the body. Here, we demonstrate that as a consequence of consuming high glycemic foods, the polyol pathway, a metabolic route in which fructose is produced from glucose, is activated, triggering a deleterious mechanism whereby glucose, sorbitol and alcohol induce severe liver disease and growth retardation in aldolase B knockout mice. We show that generically and pharmacologically blocking this pathway significantly improves metabolic dysfunction and thriving and increases the tolerance of aldolase B knockout mice to dietary triggers of endogenous fructose production.

Diurnal Variations in Serum Uric Acid, Xanthine, and Xanthine Oxidoreductase Activity in Male Patients with Coronary Artery Disease.

Hyperuricemia is influenced by diet and can cause gout. Whether it is a potential risk factor for cardiovascular disease (CVD) remains controversial, and the mechanism is unclear. Similar to CVDs, gout attacks occur more frequently in the morning and at night. A possible reason for this is the diurnal variation in uric acid (UA), However, scientific data regarding this variation in patients with CVD are not available. Thus, we aimed to investigate diurnal variations in serum levels of UA and plasma levels of xanthine, hypoxanthine, and xanthine oxidoreductase (XOR) activity, which were measured at 18:00, 6:00, and 12:00 in male patients with coronary artery disease. Thirty eligible patients participated in the study. UA and xanthine levels significantly increased from 18:00 to 6:00 but significantly decreased from 6:00 to 12:00. By contrast, XOR activity significantly increased both from 18:00 to 6:00 and 6:00 to 12:00. Furthermore, the rates of increase in UA and xanthine levels from night to morning were significantly and positively correlated. In conclusion, UA and xanthine showed similar diurnal variations, whereas XOR activity showed different diurnal variations. The morning UA surge could be due to UA production. The mechanism involved XOR activity, but other factors were also considered.

Sugar, salt, immunity and the cause of primary hypertension.

Despite its discovery more than 150 years ago, the cause of primary hypertension remains unknown. Most studies suggest that hypertension involves genetic, congenital or acquired risk factors that result in a relative inability of the kidney to excrete salt (sodium chloride) in the kidneys. Here we review recent studies that suggest there may be two phases, with an initial phase driven by renal vasoconstriction that causes low-grade ischemia to the kidney, followed by the infiltration of immune cells that leads to a local autoimmune reaction that maintains the renal vasoconstriction. Evidence suggests that multiple mechanisms could trigger the initial renal vasoconstriction, but one way may involve fructose that is provided in the diet (such as from table sugar or high fructose corn syrup) or produced endogenously. The fructose metabolism increases intracellular uric acid, which recruits NADPH oxidase to the mitochondria while inhibiting AMP-activated protein kinase. A drop in intracellular ATP level occurs, triggering a survival response. Leptin levels rise, triggering activation of the sympathetic central nervous system, while vasopressin levels rise, causing vasoconstriction in its own right and stimulating aldosterone production via the vasopressin 1b receptor. Low-grade renal injury and autoimmune-mediated inflammation occur. High-salt diets can amplify this process by raising osmolality and triggering more fructose production. Thus, primary hypertension may result from the overactivation of a survival response triggered by fructose metabolism. Restricting salt and sugar and hydrating with ample water may be helpful in the prevention of primary hypertension.

High Fructose Corn Syrup Accelerates Kidney Disease and Mortality in Obese Mice with Metabolic Syndrome.

The presence of obesity and metabolic syndrome is strongly linked with chronic kidney disease (CKD), but the mechanisms responsible for the association are poorly understood. Here, we tested the hypothesis that mice with obesity and metabolic syndrome might have increased susceptibility to CKD from liquid high fructose corn syrup (HFCS) by favoring the absorption and utilization of fructose. We evaluated the pound mouse model of metabolic syndrome to determine if it showed baseline differences in fructose transport and metabolism and whether it was more susceptible to chronic kidney disease when administered HFCS. Pound mice have increased expression of fructose transporter (Glut5) and fructokinase (the limiting enzyme driving fructose metabolism) associated with enhanced fructose absorption. Pound mice receiving HFCS rapidly develop CKD with increased mortality rates associated with intrarenal mitochondria loss and oxidative stress. In pound mice lacking fructokinase, the effect of HFCS to cause CKD and early mortality was aborted, associated with reductions in oxidative stress and fewer mitochondria loss. Obesity and metabolic syndrome show increased susceptibility to fructose-containing sugars and increased risk for CKD and mortality. Lowering added sugar intake may be beneficial in reducing the risk for CKD in subjects with metabolic syndrome.

Impact of Hyper- and Hypo-Uricemia on Kidney Function.

Uric acid (UA) forms monosodium urate (MSU) crystals to exert proinflammatory actions, thus causing gout arthritis, urolithiasis, kidney disease, and cardiovascular disease. UA is also one of the most potent antioxidants that suppresses oxidative stress. Hyper andhypouricemia are caused by genetic mutations or polymorphism. Hyperuricemia increases urinary UA concentration and is frequently associated with urolithiasis, which is augmented by low urinary pH. Renal hypouricemia (RHU) is associated with renal stones by increased level of urinary UA, which correlates with the impaired tubular reabsorption of UA. Hyperuricemia causes gout nephropathy, characterized by renal interstitium and tubular damage because MSU precipitates in the tubules. RHU is also frequently associated with tubular damage with elevated urinary beta2-microglobulin due to increased urinary UA concentration, which is related to impaired tubular UA reabsorption through URAT1. Hyperuricemia could induce renal arteriopathy and reduce renal blood flow, while increasing urinary albumin excretion, which is correlated with plasma xanthine oxidoreductase (XOR) activity. RHU is associated with exercise-induced kidney injury, since low levels of SUA could induce the vasoconstriction of the kidney and the enhanced urinary UA excretion could form intratubular precipitation. A U-shaped association of SUA with organ damage is observed in patients with kidney diseases related to impaired endothelial function. Under hyperuricemia, intracellular UA, MSU crystals, and XOR could reduce NO and activate several proinflammatory signals, impairing endothelial functions. Under hypouricemia, the genetic and pharmacological depletion of UA could impair the NO-dependent and independent endothelial functions, suggesting that RHU and secondary hypouricemia might be a risk factor for the loss of kidney functions. In order to protect kidney functions in hyperuricemic patients, the use of urate lowering agents could be recommended to target SUA below 6 mg/dL. In order to protect the kidney functions in RHU patients, hydration and urinary alkalization may be recommended, and in some cases an XOR inhibitor might be recommended in order to reduce oxidative stress.