Serum uric acid shows a J-shaped trend with coronary mortality in non-insulin-dependent diabetic elderly people. The CArdiovascular STudy in the ELderly (CASTEL)

Drug-Induced Hypouricemia

Hypouricemia is defined as a serum uric acid concentration of ≤ 2.0 mg/dL or 119 μmol/L. Hypouricemia may occur secondarily to a number of underlying conditions, including severe hepatocellular disease, neoplasia, defective renal tubular reabsorption of uric acid, inherited metabolic defect in purine metabolism, and drugs. Medications are an important cause of hypouricemia. They can cause hypouricemia by a variety of mechanisms. Drug-induced hypouricemia mostly occurs as overtreatment of hyperuricemia by urate-lowering therapies including xanthine oxidase inhibitors, uricosuric agents and uricases. Drugs not used in the treatment of gout may also lead to a decrease of uric acid levels. In this literature review, medications leading to hypouricemia are summarized with regard to their mechanism of action and clinical significance.

Association of serum uric acid to high-density lipoprotein cholesterol ratio with all-cause and cardiovascular mortality in patients with diabetes or prediabetes: a prospective cohort study

Background and aims

The serum uric acid (UA) to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) is a novel biomarker that indicates inflammation and metabolic disorders. Also, it has been shown that UHR correlates with the risk of cardiovascular disease. Despite this, limited research exists on its prognostic significance. This study aimed to explore the association of UHR with all-cause and cardiovascular mortality in patients with diabetes or prediabetes.

Methods

This cohort study included 18,804 participants from the National Health and Nutrition Examination Survey (NHANES) 2005-2018 with diabetes or prediabetes aged 20 years or older, followed until December 31, 2019. Patients with diabetes or prediabetes were grouped according to quartiles of UHR, which was calculated as serum UA (mg/dL)/HDL-C (mg/dL). Kaplan-Meier survival analysis, multivariable Cox proportional hazards regression models, restricted cubic spline analysis, and threshold effects were performed to assess the association between baseline UHR and all-cause and cardiovascular mortality. Subgroup analysis and sensitivity analysis were also conducted.

Results

During a median follow-up of 80 months, a total of 2,748 (14.61%) deaths occurred, including 869 (4.63%) cardiovascular deaths. Kaplan-Meier survival analysis revealed that the highest quartile of UHR had the highest mortality rates. Multivariable Cox regression analysis indicated that individuals in the highest quartile of UHR had a significantly higher risk of all-cause mortality (HR: 1.24, 95% CI: 1.07-1.45) and cardiovascular mortality (HR: 1.56, 95% CI: 1.19-2.04) compared to those in the second quartile. A J-shaped association between UHR and both all-cause and cardiovascular mortality was observed, with threshold points of 13.73% and 9.39%, respectively. Specifically, when UHR was above the respective thresholds, the HRs of a 10% increment of UHR for all-cause mortality and cardiovascular mortality were 1.45 (95% CI: 1.31-1.61) and 1.38 (95% CI: 1.20-1.60). However, UHR below the threshold did not significantly correlate with mortality. Furthermore, subgroup analyses showed that the correlation of UHR with all-cause mortality was significantly modified by sex and age, with a persistent positive correlation observed in women and those aged < 60.

Conclusion

Higher UHR was correlated with increased all-cause and cardiovascular mortality in patients with diabetes or prediabetes.

J-shaped Association between Serum Uric Acid Levels and the Prevalence of a Reduced Kidney Function: A Cross-sectional Study Using Japanese Health Examination Data

Objective While an association between a reduced kidney function and hyperuricemia has been reported, its association with hypouricemia is not well understood. The present study therefore investigated this association. Methods Using a large Japanese health examination dataset, we performed a multivariable logistic regression analysis to assess the association between serum uric acid (SUA) levels and a reduced kidney function. The covariates included the age, body mass index, alcohol intake, and the presence of hypertension, dyslipidemia, or diabetes. Patients This study included 227,672 patients (104,854 men; 46.1%), and the analyses were performed separately for men and women. The patients were classified into 5 groups: hypouricemia (SUA ≤2.0 mg/dL) (1st) and four other (2nd-5th) groups with SUA levels of ≤2.0, 2.1-5.1, 5.2-5.9, 6.0-6.8, ≥6.9 mg/dL in men and ≤2.0, 2.1-3.7, 3.8-4.4, 4.5-5.1, ≥5.2 mg/dL in women, respectively. Results The characteristics of the study population were as follows: men, age 55.9±14.9 years old, SUA 5.9±1.3 mg/dL, estimated glomerular filtration rate (eGFR) 80.0±17.2 mL/min/1.73 m2, and a reduced kidney function (eGFR <60.0 mL/min/1.73 m2) 9.4%; women, age 57.3±15.0 years old, SUA 4.5±1.1 mg/dL, eGFR 81.2±18.0 mL/min/1.73 m2, and a reduced kidney function 9.4%. Compared with the 2nd group, the other 4 groups groups had a significantly higher prevalence of a reduced kidney function [odds ratio (OR), 2.58; 95% confidence interval (CI), 1.64-4.06 in men; OR, 1.66; 95% CI, 1.16-2.39 in women]. Conclusion The prevalence of a reduced kidney function was high in both men and women in the hypouricemia and high-SUA groups. SUA levels and the prevalence of a reduced kidney function showed a J-shaped association.

Uric acid in health and disease: From physiological functions to pathogenic mechanisms

Owing to renal reabsorption and the loss of uricase activity, uric acid (UA) is strictly maintained at a higher physiological level in humans than in other mammals, which provides a survival advantage during evolution but increases susceptibility to certain diseases such as gout. Although monosodium urate (MSU) crystal precipitation has been detected in different tissues of patients as a trigger for disease, the pathological role of soluble UA remains controversial due to the lack of causality in the clinical setting. Abnormal elevation or reduction of UA levels has been linked to some of pathological status, also known as U-shaped association, implying that the physiological levels of UA regulated by multiple enzymes and transporters are crucial for the maintenance of health. In addition, the protective potential of UA has also been proposed in aging and some diseases. Therefore, the role of UA as a double-edged sword in humans is determined by its physiological or non-physiological levels. In this review, we summarize biosynthesis, membrane transport, and physiological functions of UA. Then, we discuss the pathological involvement of hyperuricemia and hypouricemia as well as the underlying mechanisms by which UA at abnormal levels regulates the onset and progression of diseases. Finally, pharmacological strategies for urate-lowering therapy (ULT) are introduced, and current challenges in UA study and future perspectives are also described.

The association of low serum uric acid with mortality in older people is modified by kidney function: National Health and Nutrition Examination Survey (NHANES) 1999-2018

BACKGROUND

In older individuals, the role of low serum uric acid (SUA) as risk factor for mortality is debated. We therefore studied whether SUA levels, particularly low SUA concentrations, are associated with all-cause and cardiovascular (CV) mortality in older population, and to clarify potential effect modification of kidney function.

METHODS

We identified 14,005 older people in National Health and Nutrition Examination Survey (NHANES) data from 1999 to 2018. SUA was measured only at baseline. The relationship between SUA and mortality was assessed using Cox proportional hazards models and restricted cubic spline Cox regression stratified by the estimated glomerular filtration rate (eGFR).

RESULTS

During mean 8.3 years of follow-up, 4852 all-cause death and 1602 CV death were recorded. A significant U-shaped association was observed between SUA with all-cause mortality, with the lowest risk concentration of 5.5 mg/dL. Comparing to the reference group (5 to 7 mg/dL), the HR of 2 to < 5 mg/dL group was 1.11 (1.03-1.21) and 1.14 (1.00-1.30). This relationship was more pronounced in participants with an eGFR ≥ 60 ml/min/1.73m2 (HR, 1.16; 95%CI, 1.06-1.28). This situation similarly occurred in Urine protein negative group (HR, 1.14; 95%CI, 1.04-1.25).

CONCLUSIONS

Low SUA concentrations are associated with an increased risk in all-cause and CV mortality among older participants. Extremely low SUA concentrations are especially undesirable, especially in the older adults with normal kidney function.

J-shaped association between uric acid and breast cancer risk: a prospective case-control study

BACKGROUND/AIM

In terms of breast cancer risk, there is no consensus on the effect of uric acid (UA) levels. The aim of our study was to clarify the link between UA and breast cancer risk in a prospective case-control study and to find the UA threshold point.

METHODS

We designed a case-control study with 1050 females (525 newly diagnosed breast cancer patients and 525 controls). We measured the UA levels at baseline and confirmed the incidence of breast cancer through postoperative pathology. We used binary logistic regression to study the association between breast cancer and UA. In addition, we performed restricted cubic splines to evaluate the potential nonlinear links between UA and breast cancer risk. We used threshold effect analysis to identify the UA cut-off point.

RESULTS

After adjusting for multiple confounding factors, we found that compared with the referential level (3.5-4.4 mg/dl), the odds ratio (OR) of breast cancer was 1.946 (95% CI 1.140-3.321) (P < 0.05) in the lowest UA level and 2.245 (95% CI 0.946-5.326) (P > 0.05) in the highest level. Using the restricted cubic bar diagram, we disclosed a J-shaped association between UA and breast cancer risk (P-nonlinear < 0.05) after adjusting for all confounders. In our study, 3.6 mg/dl was found to be the UA threshold which acted as the optimal turning point of the curve. The OR for breast cancer was 0.170 (95% CI 0.056-0.512) to the left and 1.283 (95% CI 1.074-1.532) to the right of 3.6 mg/dl UA (P for log likelihood ratio test < 0.05).

CONCLUSION

We found a J-shaped association between UA and breast cancer risk. Controlling the UA level around the threshold point of 3.6 mg/dl provides a novel insight into breast cancer prevention.

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.

Dysuricemia-A New Concept Encompassing Hyperuricemia and Hypouricemia

The importance of uric acid, the final metabolite of purines excreted by the kidneys and intestines, was not previously recognized, except for its role in forming crystals in the joints and causing gout. However, recent evidence implies that uric acid is not a biologically inactive substance and may exert a wide range of effects, including antioxidant, neurostimulatory, proinflammatory, and innate immune activities. Notably, uric acid has two contradictory properties: antioxidant and oxidative ones. In this review, we present the concept of "dysuricemia", a condition in which deviation from the appropriate range of uric acid in the living body results in disease. This concept encompasses both hyperuricemia and hypouricemia. This review draws comparisons between the biologically biphasic positive and negative effects of uric acid and discusses the impact of such effects on various diseases.

Association between serum uric acid and phase angle in patients with type 2 diabetes mellitus: A cross-sectional study

Background

The purpose of this analysis was to investigate the associations between serum uric acid and phase angle in patients with type 2 diabetes mellitus.

Methods

In this retrospective cross-sectional study, we included 200 type 2 diabetes mellitus (T2DM) patients treated during 2018-2019 at Zhongda Hospital Southeast University. Phase angle (PhA) and other body composition indicators were measured by bioelectrical impedance analysis (BIA). All patients underwent routine clinical examinations on the day of hospitalization, and the basic information and clinical symptoms of these patients were recorded.

Results

Serum uric acid (UA) was significantly associated with PhA (p <0.001). Overall, in the crude model and minor, all adjusted models (crude model, Models I-II), the phase angle increased as the tertiles of serum uric acid increased. In the minor adjusted model (Model I, adjustment for age and duration) fully adjusted model (Model II, adjustment for age, duration, Lpa, BMI, and WHR), the adjusted β for participants in tertiles of serum uric acid were 0.26 (95% CI: 0.05-0.46) and 0.32 (95% CI: 0.11-0.54), respectively, compared with those in the lowest tertile 1.

Conclusion

There was a nonlinear relationship between serum uric acid and PhA in T2DM patients, and the phase angle increased as uric acid increased within a certain range, and this effect disappeared when uric acid exceeded a certain value.

Sex differences between serum uric acid levels and cardiovascular outcomes in patients with coronary artery disease after stent implantation

Background

The relationship between elevated serum uric acid (SUA) levels and cardiovascular outcomes after stent implantation remains uncertain. This study sought to evaluate the impact of SUA on 12-month cardiovascular outcomes after stent implantation.

Methods

We performed a retrospective study of patients who successfully underwent stent implantation and enrolled 3,222 patients with coronary artery disease (CAD) from a single center. SUA levels were measured before stent implantation. The patients were divided into six groups (<4, 4-4.9, 5-5.9, 6-6.9, 7-7.9 and ≥ 8 mg/dL) at SUA intervals of 1.0 mg/dL. The incidence of cardiovascular outcomes in the six groups was monitored for 1 year after stent implantation and the hazard ratios were estimated. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) for cardiovascular outcomes were estimated using a Cox proportional hazard regression analysis. The primary endpoint was all-cause death. The secondary endpoint was a composite of all-cause death, myocardial infarction, target vessel revascularization, stent thrombosis and stroke. The follow-up duration was 12 months.

Results

Over the 12-month follow-up period, there were 101 all-cause deaths and 218 MACCE. After adjustment for several parameters, the group with SUA levels of more than or equal to 8 mg/dL had significantly higher hazard ratios in the incidence of all-cause death or MACCE. The group with <4.0 mg/dL had significantly higher hazard ratios in all-cause death only in male patients. In contrast, there were no significant differences observed for cardiovascular outcomes in female patients.

Conclusions

Our study identified a U-shaped association between SUA levels and cardiovascular outcomes during 12-month follow-up for males, but not for females. Further studies are warranted to clarify the sex differences between SUA levels and clinical outcomes.

U-shaped association of uric acid to overall-cause mortality and its impact on clinical management of hyperuricemia

Serum uric acid (SUA) is significantly elevated in obesity, gout, type 2 diabetes mellitus, and the metabolic syndrome and appears to contribute to the renal, cardiovascular and pulmonary comorbidities that are associated with these disorders. Most previous studies have focused on the pathophysiologic effects of high levels of uric acid (hyperuricemia). More recently, research has also shifted to the impact of hypouricemia, with multiple studies showing the potentially damaging effects that can be caused by abnormally low levels of SUA. Along with these observations, recent inconclusive data from human studies evaluating the treatment of hyperuricemia with xanthine oxidoreductase (XOR) inhibitors have added to the debate about the causal role of UA in human disease processes. SUA, which is largely derived from hepatic degradation of purines, appears to exert both systemic pro-inflammatory effects that contribute to disease and protective antioxidant properties. XOR, which catalyzes the terminal two steps of purine degradation, is the major source of both reactive oxygen species (O2.-, H2O2) and UA. This review will summarize the evidence that both elevated and low SUA may be risk factors for renal, cardiovascular and pulmonary comorbidities. It will also discuss the mechanisms through which modulation of either XOR activity or SUA may contribute to vascular redox hemostasis. We will address future research studies to better account for the differential effects of high versus low SUA in the hope that this will identify new evidence-based approaches for the management of hyperuricemia.

The association of uric acid with mortality modifies at old age: data from the uric acid right for heart health (URRAH) study

OBJECTIVES

In older individuals, the role of serum uric acid (SUA) as risk factor for mortality is debated. This study investigated the association of SUA with all-cause and cardiovascular (CV) mortality in older adults participating in the large multicentre observational uric acid right for heart health (URRAH) study.

METHODS

Eight thousand URRAH participants aged 65+ were included in the analysis. The predictive role of SUA was assessed using Cox regression models stratified according to the cut-off age of 75. SUA was tested as continuous and categorical variable (age-specific quartiles). The prognostic threshold of SUA for mortality was analysed using receiver operating characteristic curves.

RESULTS

Among participants aged 65-74, multivariate Cox regression analysis adjusted for CV risk factors and comorbidities identified an independent association of SUA with both all-cause mortality (hazard ratio [HR] 1.169, 95% confidence interval [CI] 1.107-1.235) and CV mortality (HR 1.146, 95% CI 1.064-1.235). The cut-off value of 4.8 mg/dl discriminated mortality status. In participants aged 75+, we observed a J-shaped relationship of SUA with all-cause and CV mortality, with risk increasing at extreme SUA levels.

CONCLUSIONS

These results confirmed the predictive role of SUA for all-cause and CV mortality in older adults, while revealing considerable age-related differences. Mortality risk increased at higher SUA levels in participants aged 65-74, with a prognostic threshold of 4.8 mg/dl. The relationship between SUA and mortality was J-shaped in oldest participants. Large interventional studies are needed to clarify the benefits and possible risks of urate-lowering treatments in older adults.

Protective Effect of Luminal Uric Acid Against Indomethacin-Induced Enteropathy: Role of Antioxidant Effect and Gut Microbiota

BACKGROUND

Uric acid (UA) has anti- and pro-inflammatory properties. We previously revealed that elevated serum UA levels provide protection against murine small intestinal injury probably via luminal UA secreted in the small intestine. Luminal UA may act as an antioxidant, preventing microbiota vulnerability to oxidative stress. However, whether luminal UA is increased under hyperuricemia and plays a protective role in a dose-dependent manner as well as the mechanism by which luminal UA exerts its protective effects on enteropathy remains unknown.

METHODS

Inosinic acid (IMP) (1000 mg/kg, i.p.) was administered to obtain high serum UA (HUA) and moderate serum UA (500 mg/kg IMP, i.p.) mice. UA concentrations and levels of oxidative stress markers in the serum and intestine were measured. Mice received indomethacin (20 mg/kg, i.p.) to evaluate the effects of UA on indomethacin-induced enteropathy. Reactive oxygen species (ROS) on the ileal mucosa were analyzed. The fecal microbiota of HUA mice was transplanted to investigate its effect on indomethacin-induced enteropathy.

RESULTS

IMP increased luminal UA dose-dependently, with higher levels of luminal antioxidant markers. Indomethacin-induced enteropathy was significantly ameliorated in both UA-elevated groups, with decreased indomethacin-induced luminal ROS. The microbiota of HUA mice showed a significant increase in α-diversity and a significant difference in β-diversity from the control. Fecal microbiota transplantation from HUA mice ameliorated indomethacin-induced enteropathy.

CONCLUSIONS

The protective role of luminal UA in intestinal injury is likely exerted via oxidative stress elimination and microbiota composition modulation, preferably for gut immunity. Therefore, enhancing anaerobic conditions using antioxidants is a potential therapeutic target.

Optimal uric acid levels by febuxostat treatment and cerebral, cardiorenovascular risks: post hoc analysis of a randomised controlled trial

OBJECTIVES

Hyperuricaemia is recognised as an independent risk marker for cardiovascular and renal diseases. However, uric acid is a powerful free-radical scavenger, and the optimal level of serum uric acid (SUA) determining outcomes are unknown. This study explored whether interventional treatments for excessive SUA reduction were harmful and what constituted the optimal lowering of SUA levels for the prevention of events in patients with asymptomatic hyperuricaemia.

METHODS

This was a post hoc analysis of a randomised trial (Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy [FREED]) in which 1070 older patients with asymptomatic hyperuricaemia were enrolled and allocated to febuxostat (n = 537) or non-febuxostat treatment group (n = 533). We assessed the relationship between the end point (withdrawal or study completion) SUA levels and clinical outcomes. Primary end point was defined as a composite of all-cause mortality, cerebral and cardiorenovascular events.

RESULTS

In the febuxostat group, patients achieving SUA levels ≤4 mg/dl (hazard ratio: 2.01 [95% confidence interval: 1.05-3.87]), >4 to ≤ 5 mg/dl (2.12 [1.07-4.20], >6 to ≤ 7 mg/dl (2.42 [1.05-5.60]), and >7 mg/dl (4.73 [2.13-10.5]) had significantly higher risks for a primary composite event than those achieving SUA levels >5 to ≤ 6 mg/dl (p= 0.003 [log-rank test]). This J-shaped relationship applied to patients with renal impairment (p= 0.007 [Gray's test]) and was not significant in the non-febuxostat treatment group (p= 0.212 [log-rank test]).

CONCLUSION

Optimal SUA levels by febuxostat treatment is 5-6 mg/dl for reducing all-cause mortality, cerebral, cardiovascular, and renal events. Excessive SUA reduction may be harmful in older hyperuricaemic populations.

TRIAL REGISTRATION

ClinicalTrial.gov, https://clinicaltrials.gov, NCT01984749.

Identification of two novel heterozygous SLC2A9 mutations in a Chinese woman and review of literature

OBJECTIVE

This study is aimed to describe the clinical and genetic characteristics of a Chinese woman diagnosed with renal hypouricemia type 2 (RHUC2). We also summarize the advances in research on RHUC2 by reviewing related literature.

METHODS

We measured clinical parameters of a 57-year-old female and performed whole-exome sequencing to screen for mutations. Human embryonic kidney 293 cells were transiently transfected with plasmids containing wild-type or mutants. Relative mRNA quantification was determined by real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR).

RESULTS

This patient was diagnosed with diabetes and coronary heart disease. In addition, a decrease in 24-hour urinary chloride was observed. Two novel heterozygous variants of SLC2A9 (NM_020041.2): c.682-2_682-1insC and c.267C > G (p.Y89X) were identified. The mini-gene splicing assay revealed that c.682-2_682-1insC variant resulted in a frameshift mutation p. E228PfsX23. There was a statistically significant difference in mRNA expression level between the two mutants and the wild-type.

CONCLUSIONS

These findings strongly suggest that the two novel mutations are the causative agents of RHUC2. In particular, our findings provide further insights into the function of SLC2A9 and mechanisms of the complications.

Serum Uric Acid and Diabetes: From Pathophysiology to Cardiovascular Disease

Hyperuricemia, has been traditionally related to nephrolithiasis and gout. However, it has also been associated with the development of type 2 diabetes mellitus (T2DM) and cardiometabolic and cardiovascular diseases. Pathophysiologically, elevated serum uric acid (SUA) levels may be associated with abnormal lipid and glucose metabolism. In this narrative review, we consider the associations between hyperuricemia, hyperglycemia, atherosclerosis and thrombosis. Furthermore, we comment on the available evidence linking elevated SUA levels with the incidence and outcomes of coronary heart disease, stroke, peripheral artery disease and non-alcoholic fatty liver in subjects with T2DM. The effects of antidiabetic drugs (e.g. metformin, pioglitazone, sulfonylureas, dipeptidyl peptidase 4 inhibitors, glucagon-like peptide-1 receptor agonists, sodium-glucose cotransporter 2 inhibitors and insulin) on SUA concentrations are also reviewed.

J-shaped curve for the association between serum uric acid levels and the prevalence of blood pressure abnormalities

Low and high serum uric acid levels are associated with an increased risk of cardiovascular diseases. However, whether there is a similar association between serum uric acid levels and blood pressure abnormalities has not yet been elucidated. Data from 236,221 individuals (age, 56.0 ± 15.0 years; 107,146 men) who underwent routine health checkups were analyzed. Participants with a serum uric acid level ≤2.0 mg/dL were separated, and the remaining participants were divided into quartiles according to their serum uric acid levels. Among each group, the proportions of participants with high blood pressure (≥130/80 mmHg, and/or medication) and hypertension (≥140/90 mmHg, and/or medication), were calculated. The adjusted odds ratio of each group compared to the group with the lowest proportion of blood pressure abnormalities was calculated. The participants were divided into five groups according to their serum uric acid levels, ≤2.0, 2.1-4.0, 4.1-5.0, 5.1-6.0, and ≥6.1 mg/dL, and the prevalence of high blood pressure was 49.0, 44.6, 52.3, 58.6, and 65.3% and that of hypertension was 31.0, 27.4, 33.5, 38.7, and 43.8%, respectively. Compared to the second-lowest serum uric acid group (2.1-4.0 mg/dL), groups with higher serum uric acid levels (4.1-5.0, 5.1-6.0, and ≥6.1 mg/dL), as well as the group with the lowest serum uric acid level (≤2.0 mg/dL), showed significantly higher odds ratios for high blood pressure and hypertension. High and low serum uric acid levels were significantly associated with an increased prevalence of high blood pressure and followed a J-shaped curve.

Prognostic impacts of serum uric acid levels in patients with chronic heart failure: insights from the CHART-2 study

AIMS

Prognostic impacts of serum uric acid (UA) levels in patients with chronic heart failure (CHF) remain inconclusive, especially for the whole range of serum UA levels.

METHODS AND RESULTS

In the Chronic Heart Failure Registry and Analysis in the Tohoku District-2 (CHART-2) study, we enrolled 4652 consecutive patients with CHF and classified them into four groups based on baseline serum UA levels by the Classification and Regression Tree: G1 (<3.8 mg/dL, N = 313), G2 (3.8-7.1 mg/dL, N = 3070), G3 (7.2-9.2 mg/dL, N = 1018), and G4 (>9.2 mg/dL, N = 251). Mean age was 71 ± 12, 69 ± 12, 68 ± 13, and 69 ± 15 years in G1, G2, G3, and G4, respectively (P < 0.001). During the median follow-up of 6.3 years, in G1, G2, G3, and G4, 111 (35%), 905 (29%), 370 (36%), and 139 (55%) patients died and 79 (25%), 729 (24%), 300 (29%), and 115 (46%) experienced heart failure hospitalization, respectively (both P < 0.001). G1 was characterized by a significantly high prevalence of women as compared with G2, G3, and G4 (59%, 32%, 24%, and 23%, respectively). Serum creatinine levels (0.8 ± 0.4, 0.9 ± 0.4, 1.2 ± 0.6, and 1.4 ± 0.8 mg/dL, respectively), prevalence of atrial fibrillation (34%, 39%, 45%, and 50%, respectively), and diuretics use (36%, 45%, 67%, and 89%, respectively) increased from G1, G2, G3 to G4 (all P < 0.001), while left ventricular ejection fraction decreased from G1, G2, G3 to G4 (59 ± 15, 58 ± 15, 54 ± 15, and 52 ± 17%, respectively, P < 0.001). Multivariable Cox proportional hazards models showed that, as compared with G2, both G1 and G4 had increased incidence of all-cause death [adjusted hazard ratio (aHR) 1.34, 95% confidence interval (CI) 1.08-1.67, P = 0.009; aHR 1.28, 95% CI 1.02-1.61, P = 0.037, respectively] and heart failure admission (aHR 1.39, 95% CI 1.09-1.78, P = 0.008 and aHR 1.35, 95% CI, 1.06-1.71, P = 0.014, respectively). This U-shaped relationship was evident in the elderly patients. Furthermore, abnormal transitions to either higher or lower levels of serum UA from G2 were associated with increased mortality (aHR 1.29, 95% CI 1.06-1.57, P = 0.012; aHR 1.57, 95% CI 1.12-2.20, P = 0.009).

CONCLUSIONS

These results demonstrate that serum UA levels have the U-shaped prognostic effects and abnormal transitions to either higher or lower levels are associated with poor prognosis in the elderly patients with CHF.

Hyperuricemia and the Risk of Heart Failure: Pathophysiology and Therapeutic Implications

The association between hyperuricemia and cardiovascular disease (CVD) has been reported and studied in the past two decades. Xanthine oxidase (XO) induced uric acid (UA) serves as a risk factor and has the independent prognostic and functional impact of heart failure (HF), but whether it plays a positive role in the pathogenesis of HF has remained unclear. Growing evidence suggest the up-regulated XO avtivity and increased production of free oxygen radical (ROS) correspondingly are the core pathogenesis of HF with hyperuricemia, which results in a whole cluster of pathophysiologic cardiovascular effects such as oxidative stress, endothelial dysfunction, vascular inflammation, left ventricular (LV) dysfunction as well as insulin resistance (IR). The use of XO inhibition represents a promising therapeutic choice in patients with HF due to its dual effect of lowering serum UA levels as well as reducing ROS production. This review will discuss the pathophysiologic mechanisms of hyperuricemia with HF, the targeted therapeutic interventions of UA lowering therapies (ULT) with XO inhibition and mechanism underlying beneficial effects of ULT. In addition, the review also summarizes current evidence on the role of ULT in HF and compares CV risk between allopurinol and febuxostat for practical and clinical purposes. Guidelines and implementation of CV risk management in daily practice will be discussed as well.

Association between mortality and serum uric acid levels in non-diabetes-related chronic kidney disease: An analysis of the National Health and Nutrition Examination Survey, USA, 1999-2010

The relationship between serum uric acid (SUA) and cardiovascular (CV) mortality in patients with chronic kidney disease (CKD) has been described as either a J- or U-shaped function. However, its effect in non-diabetic CKD (and varying severities of CKD) remains unclear. We analyzed the database of the National Health and Nutrition Examination Survey, USA, from the years 1999 to 2010. We then grouped the subjects into 4 categories according to their SUA levels: (a) < 5 mg/dl, (b) 5-7 mg/dl, (c) 7-9 mg/dl and (d) ≥ 9 mg/dl. For mortality comparison purposes (CV related, cancer related and all-cause mortality), we set the SUA group of 5-7 mg/dl as the reference. We also separated this population into moderate (stage 3) and severe (stages 4 and 5) CKD. A total of 1860 participants were included in this study. Results showed that the group with the lowest SUA levels (< 5 mg/dl), were the least male gender (19.25%), had the lowest body mass index (26.41(95% CI = 25.66-27.16) kg/m2), highest systolic blood pressure (139.02 (95% CI 135.72-142.32) mmHg), highest high-density cholesterol (59.55 (95% CI 57.37-61.74) mg/dl), lowest blood glucose (95.46 (95% CI 93.16-97.76) mg/dl), highest total cholesterol (210.31 (95% CI 203.36-217.25) mg/dl), lowest serum albumin (4.09 (95% CI 4.04-4.14) g/dl), highest estimated glomerular filtration rate (eGFR) (47.91 (95% CI 45.45-50.49) ml/min/1.732m2), least history of hypertension (54.4%), and least total energy intake (1643.7 (95% CI 1536.13-1751.27) kcal/day). In the group with SUA ≥ 9 mg/dl, patients had higher all-cause mortality (HR = 2.15) whatever their baseline CVD status. In non-DM CKD patients with a CVD history, the group with SUA ≥ 9 mg/dl had the highest all-cause mortality (HR = 5.39), CVD mortality (HR = 8.18) and CVD or cancer (HR = 8.25) related mortality. In non-DM patients with severe CKD (eGFR < 30 ml/min/1.732m2), the group with SUA < 5 had a significantly increased all-cause mortality. On the contrary, in non-DM patients with moderate CKD (eGFR = 30-60 ml/min/1.832m2), the group with SUA ≥ 9 had a significantly increased all-cause mortality. In moderate non-DM CKD, SUA ≥ 9 mg/dl is associated with higher all-cause mortality. However, once progressing to severe non-DM CKD, SUA < 5 mg/dl is associated with higher all-cause mortality (even though it has the least risk factors for metabolic syndrome).

Serum uric acid, predicts heart failure in a large Italian cohort: search for a cut-off value the URic acid Right for heArt Health study

OBJECTIVE

To assess the prognostic cut-off values of serum uric acid (SUA) in predicting fatal and morbid heart failure in a large Italian cohort in the frame of the Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension.

METHODS

The URic acid Right for heArt Health (URRAH) study is a nationwide, multicentre, cohort study involving data on individuals aged 18-95 years, recruited on a community basis from all regions of Italy under the patronage of the Italian Society of Hypertension with a mean follow-up period of 128 ± 65 months. Incident heart failure was defined on the basis of International Classification of Diseases Tenth Revision codes and double-checked with general practitioners and hospital files. Multivariate Cox regression models having fatal and morbid heart failure as dependent variables, adjusted for sex, age, SBP, diabetes, estimated glomerular filtration rate, smoking habit, ethanol intake, BMI, haematocrit, LDL cholesterol, previous diagnosis of heart failure and use of diuretics as possible confounders, were used to search for an association between SUA as a continuous variable and heart failure. By means of receiver operating characteristic curves, two prognostic cut-off values (one for all heart failure and one for fatal heart failure) were identified as able to discriminate between individuals doomed to develop the event. These cut-off values were used as independent predictors to divide individuals according to prognostic cut-off values in a multivariate Cox models, adjusted for confounders.

RESULTS

A total of 21 386 individuals were included in the analysis. In Cox analyses, SUA as a continuous variable was a significant predictor of all [hazard ratio 1.29 (1.23-1.359), P < 0.0001] and fatal [hazard ratio 1.268 (1.121-1.35), P < 0.0001] incident heart failure. Cut-off values of SUA able to discriminate all and fatal heart failure status were identified by mean of receiver operating characteristic curves in the whole database: SUA more than 5.34 mg/dl (confidence interval 4.37-5.6, sensitivity 52.32, specificity 63.96, P < 0.0001) was the univariate prognostic cut-off value for all heart failure, whereas SUA more than 4.89 mg/dl (confidence interval 4.78-5.78, sensitivity 68.29, specificity 49.11, P < 0.0001) for fatal heart failure. The cut-off for all heart failure and the cut-off value for fatal heart failure were accepted as independent predictors in the Cox analysis models, the hazard ratios being 1.645 (1.284-2.109, P < 0.0001) for all heart failure and 1.645 (1.284-2.109, P < 0.0001) for fatal heart failure, respectively.

CONCLUSION

The results of the current study confirm that SUA is an independent risk factor for all heart failure and fatal heart failure, after adjusting for potential confounding variables and demonstrate that a prognostic cut-off value can be identified for all heart failure (>5.34 mg/dl) and for fatal heart failure (>4.89 mg/dl).

The Optimal Range of Serum Uric Acid for Cardiometabolic Diseases: A 5-Year Japanese Cohort Study

The optimal range of serum uric acid (urate) associated with the lowest risk for developing cardiometabolic diseases is unknown in a generally healthy population. This 5-year cohort study is designed to identify the optimal range of serum urate. The data were collected from 13,070 Japanese between ages 30 and 85 at the baseline (2004) from the Center for Preventive Medicine, St. Luke’s International Hospital, Tokyo. We evaluated the number of subjects (and prevalence) of those free of the following conditions: hypertension, diabetes, dyslipidemia, and chronic kidney disease (CKD) over 5 years for each 1 mg/dL of serum urate stratified by sex. Furthermore, the odds ratios (ORs) for remaining free of these conditions were calculated with multiple adjustments. Except for truly hypouricemic subjects, having lower serum urate was an independent factor for predicting the absence of hypertension, dyslipidemia, and CKD, but not diabetes. The OR of each 1 mg/dL serum urate decrease as a protective factor for hypertension, dyslipidemia, and CKD was 1.153 (95% confidence interval, 1.068–1.245), 1.164 (1.077–1.258), and 1.226 (1.152–1.306) in men; 1.306 (1.169–1.459), 1.121 (1.022–1.230), and 1.424 (1.311–1.547) in women, respectively. Moreover, comparing serum urate of 3–5 mg/dL in men and 2–4 mg/dL in women, hypouricemia could be a higher risk for developing hypertension (OR: 4.532; 0.943–21.78) and CKD (OR: 4.052; 1.181–13.90) in women, but not in men. The optimal serum urate range associated with the lowest development of cardiometabolic diseases was less than 5 mg/dL for men and 2–4 mg/dL for women, respectively.

A U-shaped association between serum uric acid with all-cause mortality in normal-weight population

BACKGROUND

It is uncertain how serum uric acid (SUA) associated with all-cause mortality among people with normal weight, hence was explored in this study.

METHODS

We enrolled participants from 1999 to 2006 National Health and Nutrition Examination Survey (NHANES) that had mortality status through 31 December 2015. We estimated adjusted hazard ratios (HRs) and 95% confidence intervals (CI) for all-cause mortality using Cox proportional hazard models, and propensity score analyses were performed. We also performed restricted cubic splines to demonstrate the nonlinear relationship, and used subgroup analysis to examine the effect modification.

RESULTS

We enrolled 6169 participants (2905 men and 3264 women, mean age 42.3 ± 21.4 years) and 1060 (17.2%) cases of all-cause mortality occurred during the mean follow-up of 11.9 years. When using the lowest quartile of SUA as referent, the multivariable HRs for all-cause mortality increased in not parallel with the quartiles of SUA (HRs were 0.92 (95%CI: 0.68, 1.23), 1.10 (95%CI: 0.82, 1.47), and 1.08 (95%CI: 0.80, 1.45) from the second to the fourth quartiles, respectively. When treating SUA as continuous variable, the HRs for all-cause mortality were 1.07 (95%CI: 1.00, 1.15; P = 0.046), 1.03 (95%CI: 0.94, 1.12; P = 0.518) and 1.15 (95%CI: 1.01, 1.31; P = 0.032) in all population, male and female subjects, respectively. Elevated SUA was associated with all-cause mortality and the propensity scores analysis showed the similar results. Subgroup analysis showed SUA was an independent risk of all-cause mortality in female (HR1.17, 95%CI: 1.05, 1.31, P = 0.005), people aged <60 years (HR1.18, 95%CI: 1.03, 1.35, P = 0.018), non-diabetic population (HR1.10, 95%CI: 1.02, 1.18, P = 0.017) and people with eGFR<90 (HR1.10, 95%CI: 1.02, 1.19, P = 0.016). Smoothing spline plots suggested the optimal SUA for the lowest risk of all-cause mortality was approximately 4.7 mg/dl.

CONCLUSION

In normal-weight population, SUA was seemed to be a U-shaped relationship with all-cause mortality.

Added predictive value of high uric acid for cardiovascular events in the Ambulatory Blood Pressure International Study

The prognostic value of uric acid (UA) for cardiovascular events (CVE) is still debated. Our purpose was to investigate the association between UA and CVE in 5243 participants of the ABP-International study with the main aim of identifying optimal sex-specific cut-points. In multivariable Cox analyses, the relationship between CVE and UA as a continuous variable was modeled by including both linear and nonlinear terms. Survival models were also estimated with UA as a categorical variable. Optimal UA cut-points were determined using an outcome-oriented approach. During a median follow-up of 5.9 years, there were 423 CVE (93 fatal). In age- and sex-adjusted Cox models, UA as a continuous variable was a significant predictor of CVE in all individuals and in men and women considered separately. The relationship between UA and CVE was linear (P-value for nonlinearity 0.54 and 0.80 for men and women, respectively). For each 1 mg/dL increase in UA, the relative hazard increase was 16% in men and 19% in women. In fully adjusted models, UA remained a significant predictor of CVE in the whole study cohort. The optimal cut-point best separating patients at low and high risk of CVE was 6.3 mg/dL for men and 4.4 mg/dL for women. Subjects with high UA had a 38% greater risk of CVE. In a sex-specific analysis, the association remained significant only in men (hazard ratio, 1.47; P < 0.01). In conclusion, high UA is an independent predictor for subsequent CVE and significantly improves risk discrimination and reclassification over the baseline multivariable model.

Association between allopurinol and cardiovascular outcomes and all-cause mortality in diabetes: A retrospective, population-based cohort study

AIM

To assess the association between allopurinol and mortality and cardiovascular outcomes in an allopurinol-treated diabetes cohort.

MATERIALS AND METHODS

We conducted a population-based retrospective cohort study in Ontario, Canada. Eligible subjects were ≥ 66 years old with diabetes and a first prescription for allopurinol between 1 April, 2002 and 31 March, 2012 and were followed until 31 March, 2016. The primary outcome was a composite: all-cause mortality, non-fatal cardiovascular event (myocardial infarction, revascularization procedure, or stroke) or congestive heart failure (CHF). Secondary outcomes were components of the primary outcome and pneumonia as a negative tracer. Allopurinol was modelled as time-varying exposed versus unexposed, daily dose category and cumulative dose using sex-specific multivariable Cox proportional hazards models.

RESULTS

Over a median follow-up of 4.65 years (interquartile range 1.79-7.81), 16 266/23 103 males and 10 571/15 313 females experienced the primary outcome. Allopurinol was associated with a reduction in the primary outcome [adjusted hazard ratios (aHR) 0.77 (95% confidence interval 0.75-0.80) and 0.81 (0.78-0.84) for males and females, respectively], driven by marked reductions in all-cause mortality and modest reductions in cardiovascular events/CHF. There was no effect of cumulative allopurinol dose on any outcome, and allopurinol was also associated with reduced risk of pneumonia in males [aHR 0.88 (0.83, 0.93)].

CONCLUSIONS

Allopurinol was associated with reduced mortality and cardiovascular outcomes. However, lack of cumulative dose effect and a positive tracer outcome in males suggests residual bias. Future research assessing whether allopurinol prevents vascular complications in diabetes requires a clinical trial.

Distribution and Characteristics of Hypouricemia within the Japanese General Population: A Cross-Sectional Study

Background and objectives: There is insufficient epidemiological knowledge of hypouricemia. In this study, we aimed to describe the distribution and characteristics of Japanese subjects with hypouricemia. Materials and Methods: Data from subjects who underwent routine health checkups from January 2001 to December 2015 were analyzed in this cross-sectional study. A total of 246,923 individuals, which included 111,117 men and 135,806 women, met the study criteria. The participants were divided into quartiles according to their serum uric acid (SUA) levels. We subdivided the subjects with hypouricemia, which was defined as SUA level ≤ 2.0 mg/dL, into two groups and compared their characteristics, including their cardiovascular risks. Results: The hypouricemia rates were 0.46% overall, 0.21% for the men and 0.66% for the women (P < 0.001). The number of the subjects with hypouricemia showed two distributions at SUA levels of 0.4–1.1 mg/dL (lower hypouricemia group), which included a peak at 0.7–0.8 mg/dL, and at SUA levels of 1.4–2.0 mg/dL (higher hypouricemia group). The men in the higher hypouricemia group had lower body mass indexes (BMI) and triglyceride (TG) levels and had higher fasting blood glucose levels than those in the lower hypouricemia group. The women in the higher hypouricemia group were younger; had lower BMI, total protein, TG, total cholesterol and low-density lipoprotein cholesterol levels; and had higher estimated glomerular filtration rates levels compared to those in the lower hypouricemia group. Conclusions: The characteristics of the individuals in the lower and higher hypouricemia groups differed significantly, indicating different pathophysiologies within each group.

Prevalence of cardiovascular disease in type 2 diabetes: a systematic literature review of scientific evidence from across the world in 2007-2017

BACKGROUND

Cardiovascular disease (CVD) is a common comorbidity in type 2 diabetes (T2DM). CVD's prevalence has been growing over time.

PURPOSE

To estimate the current prevalence of CVD among adults with T2DM by reviewing literature published within the last 10 years (2007-March 2017).

METHODS

We searched Medline, Embase, and proceedings of major scientific meetings for original research documenting the prevalence of CVD in T2DM. CVD included stroke, myocardial infarction, angina pectoris, heart failure, ischemic heart disease, cardiovascular disease, coronary heart disease, atherosclerosis, and cardiovascular death. No restrictions were placed on country of origin or publication language. Two reviewers independently searched for articles and extracted data, adjudicating results through consensus. Data were summarized descriptively. Risk of bias was examined by applying the STROBE checklist.

RESULTS

We analyzed data from 57 articles with 4,549,481 persons having T2DM. Europe produced the most articles (46%), followed by the Western Pacific/China (21%), and North America (13%). Overall in 4,549,481 persons with T2DM, 52.0% were male, 47.0% were obese, aged 63.6 ± 6.9 years old, with T2DM duration of 10.4 ± 3.7 years. CVD affected 32.2% overall (53 studies, N = 4,289,140); 29.1% had atherosclerosis (4 studies, N = 1153), 21.2% had coronary heart disease (42 articles, N = 3,833,200), 14.9% heart failure (14 studies, N = 601,154), 14.6% angina (4 studies, N = 354,743), 10.0% myocardial infarction (13 studies, N = 3,518,833) and 7.6% stroke (39 studies, N = 3,901,505). CVD was the cause of death in 9.9% of T2DM patients (representing 50.3% of all deaths). Risk of bias was low; 80 ± 12% of STROBE checklist items were adequately addressed.

CONCLUSIONS

Globally, overall CVD affects approximately 32.2% of all persons with T2DM. CVD is a major cause of mortality among people with T2DM, accounting for approximately half of all deaths over the study period. Coronary artery disease and stroke were the major contributors.

U-Shaped Association Between Serum Uric Acid Levels With Cardiovascular and All-Cause Mortality in the Elderly: The Role of Malnourishment

BACKGROUND

The link between elevated serum uric acid (SUA) levels and cardiovascular disease (CVD)-related mortality in the elderly population remains inconclusive. Nutritional status influences both SUA and CVD outcomes. Therefore, we investigated whether SUA-predicted mortality and the effect-modifying roles of malnourishment in older people.

METHODS AND RESULTS

A longitudinal Taiwanese cohort including 127 771 adults 65 years and older participating in the Taipei City Elderly Health Examination Program from 2001 to 2010 were stratified by 1-mg/dL increment of SUA. Low SUA (<4 mg/dL) strata was categorized by malnourishment status defined as Geriatric Nutritional Risk Index <98, serum albumin <38 g/L, or body mass index <22 kg/m2. Study outcomes were all-cause and CVD-related mortality. Cox models were used to estimate hazard ratios (HRs) of mortality, after adjusting for 20 demographic and comorbid covariates. Over a median follow-up of 5.8 years, there were 16 439 all-cause and 3877 CVD-related deaths. Compared with the reference SUA strata of 4 to <5 mg/dL, all-cause mortality was significantly higher at SUA <4 mg/dL (HR, 1.16; 95% confidence interval, 1.07-1.25) and ≥8 mg/dL (HR, 1.13; confidence interval, 1.06-1.21), with progressively elevated risks at both extremes. Similarly, increasingly higher CVD-related mortality was found at the SUA level <4 mg/dL (HR, 1.19; confidence interval, 1.00-1.40) and ≥7 mg/dL (HR, 1.17; confidence interval, 1.04-1.32). Remarkably, among the low SUA (<4 mg/dL) strata, only malnourished participants had greater all-cause and CVD-related mortality. This modifying effect of malnourishment remained consistent across subgroups.

CONCLUSIONS

SUA ≥8 or <4 mg/dL independently predicts higher all-cause and CVD-related mortality in the elderly, particularly in those with malnourishment.

Exploration into Uric and Cardiovascular Disease: Uric Acid Right for heArt Health (URRAH) Project, A Study Protocol for a Retrospective Observational Study

The relevance of cardiovascular role played by levels of serum uric acid is dramatically growing, especially as cardiovascular risk factor potentially able to exert either a direct deleterious impact or a synergic effect with other cardiovascular risk factors. At the present time, it still remains undefined the threshold level of serum uric acid able to contribute to the cardiovascular risk. Indeed, the available epidemiological case studies are not homogeneous, and some preliminary data suggest that the so-called "cardiovascular threshold limit" may substantially differ from that identified as a cut-off able to trigger the acute gout attack. In such scenario, there is the necessity to clarify and quantify this threshold value, to insert it in the stratification of risk algorithm scores and, in turn, to adopt proper prevention and correction strategies. The clarification of the relationship between circulating levels of uric acid and cardio-nephro-metabolic disorders in a broad sample representative of general population is critical to identify the threshold value of serum uric acid better discriminating the increased risk associated with uric acid. The Uric acid Right for heArt Health (URRAH) project has been designed to define, as primary objective, the level of uricemia above which the independent risk of cardiovascular disease may increase in a significantly manner in a general Italian population.

A Point-based Mortality Prediction System for Older Adults with Diabetes

The mortality prediction models for the general diabetic population have been well established, but the corresponding elderly-specific model is still lacking. This study aims to develop a mortality prediction model for the elderly with diabetes. The data used for model establishment were derived from the nationwide adult health screening program in Taiwan in 2007-2010, from which we applied a 10-fold cross-validation method for model construction and internal validation. The external validation was tested on the MJ health screening database collected in 2004-2007. Multivariable Cox proportional hazards models were used to predict five-year mortality for diabetic patients ≥65 years. A total of 220,832 older subjects with diabetes were selected for model construction, of whom 23,241 (10.5%) died by the end of follow-up (December 31, 2011). The significant predictors retained in the final model included age, gender, smoking status, body mass index (BMI), fasting glucose, systolic and diastolic blood pressure, leukocyte count, liver and renal function, total cholesterol, hemoglobin, albumin, and uric acid. The Harrell's C in the development, internal-, and external-validation datasets were 0.737, 0.746, and 0.685, respectively. We established an easy-to-use point-based model that could accurately predict five-year mortality risk in older adults with diabetes.

On the non-linear association between serum uric acid levels and all-cause mortality rate in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

High levels of serum uric acid (SUA) are associated with increased mortality risk in the general population. Contrasting results are available in people with diabetes. The aim of our study was to investigate the association and its functional form between SUA and all cause-mortality in patients with type 2 diabetes mellitus (T2DM).

METHODS

We studied three cohorts of patients with T2DM: Gargano Mortality Study, Foggia Mortality Study, Pisa Mortality Study. All-cause mortality rate was the end point of this study.

RESULTS

The most reliable relationship between SUA levels and all-cause mortality rate was quadratic, with such model being well approximated by SUA tertiles. Both tertiles 1 and 3 were at higher risk of mortality as compared to tertile 2: Hazard Ratio (HR) [95% Confidence Interval (CI)] = 1.34 (1.07-1.68) and 1.61 (1.29-1.99), respectively. In the pseudo-sample, created from the real pooled sample, the best relationship between SUA and all-cause mortality rate was quadratic. In a tree-based Recursive Partitioning and Regression Tree analysis two subgroups at increased risk of mortality were identified, namely those with SUA levels ≥7.28 mg/dl and with SUA levels <4.16 mg/dl as compared to patients with intermediate SUA levels (i.e. 4.16-7.28), thus providing further evidence on the J-shaped relationship between SUA levels and mortality rate.

CONCLUSIONS

SUA was not linearly associated with all-cause mortality rate in patients with T2DM. For clinical and public health purposes such association is J-shaped.

stpm: an R package for stochastic process model

BACKGROUND

The Stochastic Process Model (SPM) represents a general framework for modeling the joint evolution of repeatedly measured variables and time-to-event outcomes observed in longitudinal studies, i.e., SPM relates the stochastic dynamics of variables (e.g., physiological or biological measures) with the probabilities of end points (e.g., death or system failure). SPM is applicable for analyses of longitudinal data in many research areas; however, there are no publicly available software tools that implement this methodology.

RESULTS

We developed an R package stpm for the SPM-methodology. The package estimates several versions of SPM currently available in the literature including discrete- and continuous-time multidimensional models and a one-dimensional model with time-dependent parameters. Also, the package provides tools for simulation and projection of individual trajectories and hazard functions.

CONCLUSION

In this paper, we present the first software implementation of the SPM-methodology by providing an R package stpm, which was verified through extensive simulation and validation studies. Future work includes further improvements of the model. Clinical and academic researchers will benefit from using the presented model and software. The R package stpm is available as open source software from the following links: https://cran.r-project.org/package=stpm (stable version) or https://github.com/izhbannikov/spm (developer version).

Asymptomatic hyperuricemia is a strong risk factor for resistant hypertension in elderly subjects from general population

OBJECTIVE

In clinical practice, patient characteristics predicting resistant hypertension (RH) include higher blood pressure levels, left ventricular hypertrophy, older age, obesity, chronic kidney disease and diabetes. On the contrary little is known about the role of serum uric acid (SUA) as a risk factor for RH in subjects from general population.

MATERIAL AND METHODS

580 elderly subjects aged ≥65 years were enrolled in the Risk Of Vascular complications Impact of Genetics in Old people (ROVIGO) study. RH was defined as the failure to maintain blood pressure values below 140mmHg (systolic) and 90mmHg (diastolic) despite therapeutic interventions that include appropriate lifestyle measures plus adherence to treatment with full doses of at least three antihypertensive drugs, including a diuretic. RH was confirmed using 24-h ambulatory blood pressure measurement. Hyperuricemic was defined as the subjects having SUA ≥6.8mg/dl or taking uricosuric drugs. Gender-specific odds ratio (OR) for RH was calculated by logistic regression analysis.

RESULTS

The prevalence of RH was 5.7% in the cohort and was higher in women (8.3%) than in men (3.0%, p<0.05). Independent of chronic kidney disease (OR 3.89, 95% confidence interval 1.49-10.1), hyperuricemia predicted resistant hypertension in women (odds ratio 3.11, 95% confidence intervals 1.06-9.1, p=0.03) but not in men.

CONCLUSIONS

In elderly women from the general population, an SUA value of ≥6.8mg/dl triples the risk of RH. SUA assessment should be recommended to better define the pattern of risk associated with RH.

Uric Acid Is Associated With Inflammation, Coronary Microvascular Dysfunction, and Adverse Outcomes in Postmenopausal Women

Uric acid is a risk factor for coronary artery disease in postmenopausal women, but the association with inflammation and coronary endothelial dysfunction (CED) is not well defined. The aim of this study was to determine the relationship of serum uric acid (SUA), inflammatory markers, and CED. In this prospective cohort study, SUA, high-sensitivity C-reactive protein levels, and neutrophil count were measured in 229 postmenopausal women who underwent diagnostic catheterization, were found to have no obstructive coronary artery disease, and underwent coronary microvascular function testing, to measure coronary blood flow response to intracoronary acetylcholine. The average age was 58 years (interquartile range, 52-66 years). Hypertension was present in 48%, type 2 diabetes mellitus in 5.6%, and hyperlipidemia in 61.8%. CED was diagnosed in 59% of postmenopausal women. Mean uric acid level was 4.7±1.3 mg/dL. Postmenopausal women with CED had significantly higher SUA compared with patients without CED (4.9±1.3 versus 4.4±1.3 mg/dL; P=0.02). There was a significant correlation between SUA and percent change in coronary blood flow to acetylcholine (P=0.009), and this correlation persisted in multivariable analysis. SUA levels were significantly associated with increased neutrophil count (P=0.02) and high-sensitivity C-reactive protein levels (P=0.006) among patients with CED, but not among those without CED. SUA is associated with CED in postmenopausal women and may be related to inflammation. These findings link SUA levels to early coronary atherosclerosis in postmenopausal women.

Uric Acid Level and Prevalence of Atrial Fibrillation in a Japanese General Population of 285,882

BACKGROUND

The association between serum uric acid (UA) levels and atrial fibrillation (AF) in the general population in Japan is not well known.

METHODS AND RESULTS

In total, 285,882 consecutive subjects (men, 130,897; women, 154,985; age, 58±15 years) not receiving treatment for hyperuricemia who underwent health checkups were enrolled. Subjects were stratified into deciles according to age, body mass index, estimated glomerular filtration rate, systolic blood pressure, and UA level. AF prevalence was calculated for each decile. The odds ratio that defined the decile with the lowest AF prevalence as reference was calculated in each sex. In men, the mean UA was 6.0±1.4 mg/dl; AF prevalence was 1.8% and was lowest in the decile with UA 4.4-4.9 mg/dl. Deciles with both high and low UA (5.4-5.6 mg/dl to >7.8 mg/dl and <4.3 mg/dl) were associated with significantly higher AF prevalence. In women, the mean UA was 4.5±1.1 mg/dl; AF prevalence was 0.7% and was lowest in the decile with UA 3.6-3.8 mg/dl. Deciles with highest UA (5.0-5.2 mg/dl to >5.9 mg/dl) were associated with significantly higher AF prevalence. The analysis adjusted for other clinical covariates demonstrated an independent association between UA and AF in both sexes.

CONCLUSIONS

In a representative Japanese general population, UA level was significantly associated with AF, independently of other cardiovascular risk factors. (Circ J 2016; 80: 2453-2459).

Interactive effect of serum uric acid and total bilirubin for cardiovascular disease in Chinese patients with type 2 diabetes

Serum uric acid (SUA) at high levels and bilirubin at low levels were potent antioxidant but it was uncertain that whether SUA and total bilirubin (TBIL) had additive interaction for the risk of CVD in type 2 diabetes mellitus (T2DM). We conducted a cross-sectional survey of 6713 inpatients with T2DM and admitted to 81 tertiary care hospitals. CVD was defined as having either prior coronary heart disease or stroke or peripheral arterial disease. Binary logistic regression was used to estimate odds ratios of SUA and TBIL for CVD. The effect size of additive interaction was estimated by three measures, i.e., relative excess risk due to interaction, attributable proportion due to interaction and synergy index. Among 6713 patients with T2DM, 561 (8.36%) suffered from CVD. Using ≥283 umol/L (median) to define high SUA and <11.5 umol/L (n = 2290 or 34.11%) to define low TBIL, copresence of both factors (n = 621 or 9.25%) was associated with 5.18-fold (95% CI, 4.00–6.72) risk of CVD with significant additive interactions in multivariable analysis as compared to absence of both risk factors. The copresence of both high SUA and low TBIL was associated with a large increased risk of CVD in high-risk Chinese patients with type 2 diabetes.

A J-shaped association between serum uric acid levels and poor renal survival in female patients with IgA nephropathy

Recently, low serum uric acid (SUA) levels and high SUA levels, have emerged as risk factors for cardiovascular disease, as well as for the incidence of acute kidney injury and chronic kidney disease (CKD). However, the effect of low SUA on the progression of CKD remains unclear. To evaluate the association between SUA and renal prognosis in patients with immunoglobulin A nephropathy (IgAN), one of the most common causes of CKD, we retrospectively followed 1218 patients who were diagnosed with primary IgAN by kidney biopsy between October 1979 and December 2010. Patients were divided into three groups on the basis of SUA level tertiles: low (L group), middle (M group) and high (H group) tertiles (<6.1, 6.1-7.0, and >7.0 mg dl^-1, respectively, for men and <4.4, 4.4-5.3, and >5.3 mg dl^-1, respectively, for women). The risk factors for developing end-stage renal disease (ESRD) were estimated using a Cox proportional hazards model. After a median follow-up of 5.1 years, 142 patients (11.7%) developed ESRD. The hazard ratio (95% confidence interval) showed a J-shaped trend with the tertiles in both men (1.18 (0.55-2.54), 1.00 (reference), and 1.80 (1.01-3.10) in L, M and H groups, respectively) and women (2.73 (1.10-6.76), 1.00 (reference) and 2.49 (1.16-5.34) in L, M and H groups, respectively). Notably, low SUA was significantly associated with incident ESRD in women. This finding suggests that SUA has a J-shaped association with ESRD in patients with IgAN, especially women.

How Genes Modulate Patterns of Aging-Related Changes on the Way to 100: Biodemographic Models and Methods in Genetic Analyses of Longitudinal Data

BACKGROUND AND OBJECTIVE

To clarify mechanisms of genetic regulation of human aging and longevity traits, a number of genome-wide association studies (GWAS) of these traits have been performed. However, the results of these analyses did not meet expectations of the researchers. Most detected genetic associations have not reached a genome-wide level of statistical significance, and suffered from the lack of replication in the studies of independent populations. The reasons for slow progress in this research area include low efficiency of statistical methods used in data analyses, genetic heterogeneity of aging and longevity related traits, possibility of pleiotropic (e.g., age dependent) effects of genetic variants on such traits, underestimation of the effects of (i) mortality selection in genetically heterogeneous cohorts, (ii) external factors and differences in genetic backgrounds of individuals in the populations under study, the weakness of conceptual biological framework that does not fully account for above mentioned factors. One more limitation of conducted studies is that they did not fully realize the potential of longitudinal data that allow for evaluating how genetic influences on life span are mediated by physiological variables and other biomarkers during the life course. The objective of this paper is to address these issues.

DATA AND METHODS

We performed GWAS of human life span using different subsets of data from the original Framingham Heart Study cohort corresponding to different quality control (QC) procedures and used one subset of selected genetic variants for further analyses. We used simulation study to show that approach to combining data improves the quality of GWAS. We used FHS longitudinal data to compare average age trajectories of physiological variables in carriers and non-carriers of selected genetic variants. We used stochastic process model of human mortality and aging to investigate genetic influence on hidden biomarkers of aging and on dynamic interaction between aging and longevity. We investigated properties of genes related to selected variants and their roles in signaling and metabolic pathways.

RESULTS

We showed that the use of different QC procedures results in different sets of genetic variants associated with life span. We selected 24 genetic variants negatively associated with life span. We showed that the joint analyses of genetic data at the time of bio-specimen collection and follow up data substantially improved significance of associations of selected 24 SNPs with life span. We also showed that aging related changes in physiological variables and in hidden biomarkers of aging differ for the groups of carriers and non-carriers of selected variants.

CONCLUSIONS

. The results of these analyses demonstrated benefits of using biodemographic models and methods in genetic association studies of these traits. Our findings showed that the absence of a large number of genetic variants with deleterious effects may make substantial contribution to exceptional longevity. These effects are dynamically mediated by a number of physiological variables and hidden biomarkers of aging. The results of these research demonstrated benefits of using integrative statistical models of mortality risks in genetic studies of human aging and longevity.

Association of Serum Uric Acid Levels in Psoriasis: A Systematic Review and Meta-Analysis

High levels of serum uric acid (SUAC) are frequently detected in patients with psoriasis. However, the relationship between psoriasis and hyperuricemia remains unknown. Here we conducted a meta-analysis to identify the SUAC levels in subjects with psoriasis and to determine whether there is an associated risk between psoriasis and hyperuricemia.A comprehensive search of the literature from January 1980 to November 2014 across 7 databases (MEDLINE, Embase, Cochrane Central Register, and 4 Chinese databases) was conducted to determine whether there is an associated risk between psoriasis and hyperuricemia.Among the 170 identified reports, 14 observational studies were included in this meta-analysis. We found a significant higher SUAC level (MD 0.68, 95% CI 0.26-1.09; P = 0.002) in patients with psoriasis in Western Europe, but no significant differences were found between the East Asia and India subgroup (MD 1.22, 95% CI -0.13-2.56; P = 0.08) or the Middle East subgroup (MD 0.48, 95% CI -0.49-1.44; P = 0.33). Similar results were obtained from the meta-analysis of SUAC levels in subjects with severe psoriasis.Our meta-analysis showed that the correlation between psoriasis and hyperuricemia was either ethnicity- or region-dependent and that patients with psoriasis in Western Europe were more likely to have hyperuricemia.

How the effects of aging and stresses of life are integrated in mortality rates: insights for genetic studies of human health and longevity

Increasing proportions of elderly individuals in developed countries combined with substantial increases in related medical expenditures make the improvement of the health of the elderly a high priority today. If the process of aging by individuals is a major cause of age related health declines then postponing aging could be an efficient strategy for improving the health of the elderly. Implementing this strategy requires a better understanding of genetic and non-genetic connections among aging, health, and longevity. We review progress and problems in research areas whose development may contribute to analyses of such connections. These include genetic studies of human aging and longevity, the heterogeneity of populations with respect to their susceptibility to disease and death, forces that shape age patterns of human mortality, secular trends in mortality decline, and integrative mortality modeling using longitudinal data. The dynamic involvement of genetic factors in (i) morbidity/mortality risks, (ii) responses to stresses of life, (iii) multi-morbidities of many elderly individuals, (iv) trade-offs for diseases, (v) genetic heterogeneity, and (vi) other relevant aging-related health declines, underscores the need for a comprehensive, integrated approach to analyze the genetic connections for all of the above aspects of aging-related changes. The dynamic relationships among aging, health, and longevity traits would be better understood if one linked several research fields within one conceptual framework that allowed for efficient analyses of available longitudinal data using the wealth of available knowledge about aging, health, and longevity already accumulated in the research field.

Uric acid levels within the normal range predict increased risk of hypertension: a cohort study

There are data describing that cardiovascular risks related to serum uric acid (SUA) levels may begin below the current diagnostic level for hyperuricemia. Values from 5.2 to 6.0 mg/dL were positively associated with higher cardiovascular risk. The risk associated with lower SUA levels has not been fully assessed in healthy adults. The purpose of this study was to evaluate whether normal SUA levels, even below 5-6 mg/dL, might be related to an increased risk of hypertension, compared with low-normal SUA. This cohort study was conducted in an outpatient setting: all clinics of the largest Health Maintenance Organization in Israel, in a national distribution. A total of 118,920 healthy adults (40-70 years old), who had SUA levels screened during 2002, were eligible for the study. They were stratified according to baseline SUA, and were followed for 10 years. The study endpoint was any new diagnosis of hypertension during the study period (until December 31, 2011). During 10 years of follow-up (2002-2011), 28,436 examinees developed hypertension (23.9%). Compared with the pre-defined SUA reference values (2-3 mg/dL), women with SUA within the normal range had a gradual, increased risk of developing new-onset hypertension, starting at values as low as 3-4 mg/dL (adjusted odds ratio, 1.15; 95% confidence interval, 1.01-1.30). Women with SUA 5-6 mg/dL, still accepted as normouricemia, had a 66% increased risk of developing hypertension. Younger women (ages 40-50 years at baseline) in a similar SUA subgroup (5-6 mg/dL) had an even higher risk (odds ratio, 2.25; 95% confidence interval, 1.96-2.60). Similar results were seen among men. The possibility of subtle confounders exists, despite extensive adjustment. SUA within the normal range is associated with new-onset hypertension among healthy adults, compared with once very common low-normal range values. Further study is warranted to determine new cutoffs of hypo-, normo-, and hyperuricemia, which might be far lower than current scales.

Joint Analyses of Longitudinal and Time-to-Event Data in Research on Aging: Implications for Predicting Health and Survival

Longitudinal data on aging, health, and longevity provide a wealth of information to investigate different aspects of the processes of aging and development of diseases leading to death. Statistical methods aimed at analyses of time-to-event data jointly with longitudinal measurements became known as the "joint models" (JM). An important point to consider in analyses of such data in the context of studies on aging, health, and longevity is how to incorporate knowledge and theories about mechanisms and regularities of aging-related changes that accumulate in the research field into respective analytic approaches. In the absence of specific observations of longitudinal dynamics of relevant biomarkers manifesting such mechanisms and regularities, traditional approaches have a rather limited utility to estimate respective parameters that can be meaningfully interpreted from the biological point of view. A conceptual analytic framework for these purposes, the stochastic process model of aging (SPM), has been recently developed in the biodemographic literature. It incorporates available knowledge about mechanisms of aging-related changes, which may be hidden in the individual longitudinal trajectories of physiological variables and this allows for analyzing their indirect impact on risks of diseases and death. Despite, essentially, serving similar purposes, JM and SPM developed in parallel in different disciplines with very limited cross-referencing. Although there were several publications separately reviewing these two approaches, there were no publications presenting both these approaches in some detail. Here, we overview both approaches jointly and provide some new modifications of SPM. We discuss the use of stochastic processes to capture biological variation and heterogeneity in longitudinal patterns and important and promising (but still largely underused) applications of JM and SPM to predictions of individual and population mortality and health-related outcomes.

Hyperuricaemia: a marker of increased cardiovascular risk in rheumatic patients: analysis of the ACT-CVD cohort

BACKGROUND

Gout and hyperuricaemia may be associated with increased cardiovascular risk, but analyses in different populations show conflicting results. This study investigates the impact of serum uric acid, inflammation and traditional CV risk parameters on CV event risk in patients with gouty arthritis and patients with non-gouty rheumatic disease.

METHODS

cross-sectional and prospective multivariate analysis of the relation between tertiles of serum uric acid and individual traditional CV risk factors in a cohort of gouty arthritis (GA, n=172), rheumatoid arthritis (RA, n=480) and osteoarthritis (OA, n=206) patients.

MAIN OUTCOME MEASURES

systolic blood pressure, TC/HDL ratio, GlyHb, BMI and first CV events.

RESULTS

Individual CV risk factors were significantly less favourable in GA (systolic blood pressure, TC/HDL ratio, BMI, p<0.05). In RA and OA, but not in GA, individual cardiometabolic parameters correlated with serum uric acid values (OA: RA: systolic blood pressure, TC/HDL ratio, BMI; systolic blood pressure, TC/HDL ratio, GlyHb, BMI; p<0.05). In non-GA individuals the highest tertile of serum uric acid (>0.34 mmol/L) and NT proBNP level were independent predictors of first CV events, against age and GlyHb level in GA (p<0.05). The hazard of first CV events was equally significantly increased in GA patients (HR 3.169, 95% CI 1.287-7.806) and non-GA individuals with a serum uric acid ≥ 0.34 mmol/L (HR 3.721, 95% CI 1.603-8.634) compared to non-GA individuals with a serum uric acid < 0.27.

CONCLUSIONS

GA is associated with a 3.1-fold hazard of first CV events. In non-GA rheumatic patients increasing serum uric acid is associated with increased CV risk, whereas CV risk in GA is independent of serum uric acid values. The presence of GA or a baseline serum uric acid in the upper range are possibly stronger predictors of first CV events than some traditional CV risk factors or parameters of inflammation.

Hyperuricemia as an independent predictor of vascular complications and mortality in type 2 diabetes patients: a meta-analysis

Background

Recent data have suggested that serum uric acid (SUA) level is positively associated with the development of type 2 diabetes (T2DM). Whether SUA is also independently associated with the development of vascular complications and mortality in T2DM is controversial.

Methods

A computerized literature search of MEDLINE, Embase and PubMed database was conducted and the odds ratio (OR) or hazard ratio (HR) for per 0.1mmol/l increase in SUA in each study was calculated. Cochrane’s Q and I² statistics were used to evaluate heterogeneity among studies and pooling OR and HR with 95% confidence intervals (CIs) were calculated using random-effects models and fixed-effects models. The pooled analysis was performed using Stata 10.0.

Results

Our search yielded 9 eligible articles (16 ORs and HRs) including 20,891 T2DM patients. Pooled estimates for the relationship suggested that each 0.1 mmol/l increase in SUA resulted in a 28% increase in the risk of diabetic vascular complications and a 9% increase in the risk of diabetic mortality. In stratification-analysis, the positive relationship between SUA and vascular complications remained significant irrespective of mean age, adjustment for metabolic variables and medications. However, it was inconsistent in different populations (significantly positive in the Asian but not in Australian and Italian population) and sample sizes (significantly positive in the relatively large sample size [≥1000] but non-significant in the small sample size [<1000]).

Conclusions

Results of this meta-analysis supported elevated SUA as an independent predictor of vascular complications and mortality in T2DM patients. SUA-lowering therapies might be helpful for prevention and treatment of vascular complications in this population.

Mortality in type 2 diabetes mellitus: magnitude of the evidence from a systematic review and meta-analysis

Background:

Type 2 diabetes is associated with an increase in age-related mortality. A systematic review and meta-analysis were performed to define the relative risks (RR) of all-cause or cause-specific mortality in type 2 diabetes and to determine gaps in current research.

Methods:

A comprehensive literature search was undertaken for studies (published 1990–2010) on mortality in type 2 diabetes. The study reports on the measure of mortality as defined by RR for all-cause and cause-specific mortality, heterogeneity, sensitivity analyses and biases.

Results:

In total 35 studies (220,689 patients; mean follow-up of 10.7 years) were eligible for inclusion: 33 studies reported increased mortality risks; 24 had full data on 95% confidence intervals (CIs), one study reported no excess mortality in men diagnosed after 65 years whereas three reported increased mortality in similar age groups in both sexes. Meta-analysis showed RR = 1.85 (95% CI 1.79–1.92) for all-cause mortality [men RR=1.57 (95% CI 1.46–1.68); women RR=2.0 (95% CI 1.89–2.12)], RR=1.76 (95% CI 1.66–1.88) for cardiovascular mortality and RR=2.26 (95% CI: 1.7-3.02) for stroke. There was no statistically significant evidence of publication bias.

Conclusion:

Type 2 diabetes increases mortality approximately two-fold increase and macrovascular disease is the principal cause of death.