A genetic marker of hyperuricemia predicts cardiovascular events in a meta-analysis of three cohort studies in high risk patients

Weak Association Between Genetic Markers of Hyperuricemia and Cardiorenal Outcomes: Insights From the STANISLAS Study Cohort With a 20-Year Follow-Up

Background Hyperuricemia is associated with poor cardiovascular outcomes, although it is uncertain whether this relationship is causal in nature. This study aimed to: (1) assess the heritability of serum uric acid (SUA) levels, (2) conduct a genome-wide association study on SUA levels, and (3) investigate the association between certain single-nucleotide polymorphisms and target organ damage. Methods and Results The STANISLAS (Suivi Temporaire Annuel Non-Invasif de la Santé des Lorrains Assurés Sociaux) study cohort is a single-center longitudinal cohort recruited between 1993 and 1995 (visit 1), with a last visit (visit 4 [V4]) performed ≈20 years apart. Serum lipid profile, SUA, urinary albumin/creatinine ratio, estimated glomerular filtration rate, 24-hour ambulatory blood pressure monitoring, transthoracic echocardiography, pulse wave velocity, and genotyping for each participant were assessed at V4. A total of 1573 participants were included at V4, among whom 1417 had available SUA data at visit 1. Genome-wide association study results highlighted multiple single-nucleotide polymorphisms on the SLC2A9 gene linked to SUA levels. Carriers of the most associated mutated SLC2A9 allele (rs16890979) had significantly lower SUA levels. Although SUA level at V4 was highly associated with diabetes, prediabetes, higher body mass index, CRP (C-reactive protein) levels, estimated glomerular filtration rate variation (visit 1-V4), carotid intima-media thickness, and pulse wave velocity, rs16890979 was only associated with higher carotid intima-media thickness. Conclusions Our findings demonstrate that rs16890979, a genetic determinant of SUA levels located on the SLC2A9 gene, is associated with carotid intima-media thickness despite significant associations between SUA levels and several clinical outcomes, thereby lending support to the hypothesis of a link between SUA and cardiovascular disease.

Relationship Between Change in Serum Uric Acid and Ischemic Stroke in Chinese Hypertensive Patients

Background: Limited studies focused on the association between serum uric acid (SUA) change with ischemic stroke, and their results remain controversial. The present study aimed to investigate the relationship between change in SUA with ischemic stroke among hypertensive patients.

Method: This was a retrospective cohort study. We recruited adult hypertensive patients who had two consecutive measurements of SUA levels from 2013 to 2014 and reported no history of stroke. Change in SUA was assessed as SUA concentration measured in 2014 minus SUA concentration in 2013. Multivariable Cox proportional hazards models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The Kaplan–Meier analysis and log-rank test were performed to quantify the difference in cumulative event rate. Additionally, subgroup analysis and interaction tests were conducted to investigate heterogeneity.

Results: A total of 4,628 hypertensive patients were included, and 93 cases of ischemic stroke occurred during the mean follow-up time of 3.14 years. Participants were categorized into three groups according to their SUA change tertiles [low (SUA decrease substantially): <-32.6 μmol/L; middle (SUA stable): ≥-32.6 μmol/L, <40.2 μmol/L; high (SUA increase substantially): ≥40.2 μmol/L]. In the fully adjusted model, setting the SUA stable group as reference, participants in the SUA increase substantially group had a significantly elevated risk of ischemic stroke [HR (95% CI), 1.76 (1.01, 3.06), P = 0.0451], but for the SUA decrease substantially group, the hazard effect was insignificant [HR (95% CI), 1.31 (0.75, 2.28), P = 0.3353]. Age played an interactive role in the relationship between SUA change and ischemic stroke. Younger participants (age < 65 years) tended to have a higher risk of ischemic stroke when SUA increase substantially.

Conclusion: SUA increase substantially was significantly correlated with an elevated risk of ischemic stroke among patients with hypertension.

Uric acid lowering improves insulin sensitivity and lowers blood pressure: a meta-analysis of randomized parallel-controlled clinical trials

Objectives

This meta-analysis aimed to investigate whether uric acid lowering treatment can improve β-cell function and insulin sensitivity.

Methods

PubMed, Cochrane Library, EMBASE and China Biology Medicine were searched up to March 1, 2020. Randomized controlled clinical trials of urate lowering therapy in hyperuricemia patients were included in meta-analysis. Effect size was estimated as mean difference with 95% confidence interval (CI).

Results

Our search yielded 7 eligible trials with 503 participants. This meta-analysis showed that uric acid-lowering therapy decreased fasting insulin -1.43 µIU/ml (weighted mean differences (WMD, 95% CI -2.78 to -0.09), homeostasis model assessment of insulin resistance -0.65 (WMD, 95% CI -1.05 to -0.24), systolic blood pressure -2.45 mm Hg (WMD, 95%CI -4.57 to -0.33) and diastolic blood pressure -3.41 mm Hg (WMD, 95%CI -3.87 to -2.95). However, the treatment had no significant effect on fasting plasma glucose (WMD -0.19 mmol/L, 95%CI -0.42 to 0.05), homeostasis model assessment of β-cell function index (WMD -0.02, 95%CI -0.28 to 0.24), total cholesterol (WMD 0.18 mg/dl; 95%CI, -1.39 to 1.75) and triglyceride (WMD 3.15 mg/dl, 95% CI -9.83 to 16.14).

Conclusion

Uric acid-lowering therapies might improve insulin sensitivity and lower blood pressure, but had no significant effect on HOMA-β and serum lipids.

Circulating leptin is associated with serum uric acid level and its tubular reabsorption in a sample of adult middle-aged men

PURPOSE

Leptin is associated with cardiovascular risk factors (e.g. hypertension, insulin resistance, kidney disease and excess body weight). Experimental studies showed that leptin might affect serum uric acid, by modulation of the uric acid excretion. However, there are few observational data on the relationship between leptin and uric acid in the general population. Therefore, the aim of the present study was to evaluate the relationship between leptin and uric acid and its excretion in a large middle-aged male general population.

METHODS

A sample of 930 adult male individuals (mean age: 52 years) without therapy for high uric acid was included in the analysis (the Olivetti Heart Study).

RESULTS

Uric acid was significantly and positively associated with blood pressure, BMI, waist circumference, insulin resistance, C-reactive protein and leptin (p < 0.01), while inversely with renal function (p = 0.01). The multivariate analysis confirmed the association between leptin and uric acid after adjustment for potential confounders (p < 0.01). After division for adiposity, this trend was confirmed separately for normal weight and excess body weight participants. Moreover, leptin was inversely associated with excretion of uric acid (p < 0.01), also in multivariate analysis (p = 0.03).

CONCLUSION

The results of this study indicate a positive association between circulating leptin levels and uric acid, independently of potential confounders, both in normal and excess body weight men. Furthermore, an inverse association between leptin and uric acid excretion was detected.

Associations of Triglyceride-Glucose Index and Its Derivatives with Hyperuricemia Risk: A Cohort Study in Chinese General Population

BACKGROUND

Identification and intervention of insulin resistance may be beneficial to the prevention of hyperuricemia (HUA) and its related diseases. Thus, we conducted this longitudinal study to examine the relation of triglyceride-glucose index (TyG), a simple noninsulin-based IR assessment tool, and its derivatives with the risk of HUA.

METHODS

A total of 42,387 adults who received routine health screening and were free of HUA were included for the longitudinal analyses. TyG, body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WtHR) were calculated through anthropometric and biochemical indicators. Associations of TyG, TyG-BMI, TyG-WC, and TyG-WHtR with HUA risk were estimated using Cox regression analyses.

RESULTS

The incident cases of HUA occurred in 4,230 subjects during the 138,163 person-years of observation, and the crude incidence rate of HUA was 30.6 per 1000 person-years. After multivariate adjustment, we observed an increased risk for incident HUA for the upper TyG and its derivatives' tercile. The HRs of TyG were greater than that of its components in both sexes. Compared with TyG, TyG-related parameters only had higher HRs in women but not in men.

CONCLUSIONS

TyG and its integration with obesity indicators have the potential to help risk stratification and prevention of HUA, especially among women.

Potential Dangers of Serum Urate-Lowering Therapy

In observational studies, high serum urate levels are associated with adverse outcomes, including mortality. However, the hypothesis that urate-lowering may improve nongout outcomes has not been confirmed by placebo-controlled clinical trials. On the contrary, 7 recent placebo-controlled trials of urate-lowering drugs with different mechanisms of action (uricosuric: lesinurad; xanthine oxidase inhibition: febuxostat; uricase: pegloticase) have observed higher mortality or trends to higher mortality in gout patients, with the largest decreases in serum urate. Because all urate-lowering mechanisms were implicated, this raises safety concerns about urate-lowering itself. Far from unexpected, the higher mortality associated with more intense urate-lowering is in line with the U-shaped association of urate with mortality in some observational studies. Urate accounts for most of the antioxidant capacity of plasma, and strategies to increase urate are undergoing clinical trials in neurological disease. Post hoc analysis of recent trials should explore whether the magnitude of urate-lowering is associated with adverse outcomes, and safety trials are needed before guidelines recommend lowering serum urate below certain thresholds.

Genome-wide association analysis identifies multiple loci associated with kidney disease-related traits in Korean populations

Chronic kidney disease (CKD) is an important social health problem characterized by a decrease in the kidney glomerular filtration rate (GFR). In this study, we analyzed genome-wide association studies for kidney disease-related traits using data from a Korean adult health screening cohort comprising 7,064 participants. Kidney disease-related traits analyzed include blood urea nitrogen (BUN), serum creatinine, estimated GFR, and uric acid levels. We detected two genetic loci (SLC14A2 and an intergenic region) and 8 single nucleotide polymorphisms (SNPs) associated with BUN, 3 genetic loci (BCAS3, C17orf82, ALDH2) and 6 SNPs associated with serum creatinine, 3 genetic loci (BCAS3, C17orf82/TBX2, LRP2) and 7 SNPs associated with GFR, and 14 genetic loci (3 in ABCG2/PKD2, 2 in SLC2A9, 3 in intergenic regions on chromosome 4; OTUB1, NRXN2/SLC22A12, CDC42BPG, RPS6KA4, SLC22A9, and MAP4K2 on chromosome 11) and 84 SNPs associated with uric acid levels. By comparing significant genetic loci associated with serum creatinine levels and GFR, rs9895661 in BCAS3 and rs757608 in C17orf82 were simultaneously associated with both traits. The SNPs rs11710227 in intergenic regions on chromosome 3 showing significant association with BUN is newly discovered. Genetic variations of multiple gene loci are associated with kidney disease-related traits, and differences in associations between kidney disease-related traits and genetic variation are dependent on the population. The meanings of the mutations identified in this study will need to be reaffirmed in other population groups in the future.

Uric acid and cardiovascular risk: What genes can say

BACKGROUND

Although the relationship of elevated serum uric acid levels and cardiovascular disease has been established in a great number of studies, the causal relevance of this finding remains ambiguous. An approach to evaluate the causal relevance of biomarkers is to exploit the natural randomised allocation of allelic variation in genes affecting their level, also known as Mendelian randomisation.

AIM

The aim of this paper is to review the current literature regarding serum uric acid levels and cardiovascular and renal disease risk in Mendelian randomisation studies.

METHODS

PubMed and Scopus databases were searched to retrieve Mendelian studies regarding uric acid, hyperuricaemia and cardiovascular risk.

CONCLUSIONS

Genetic evidence based on conventional and novel Mendelian randomisation approaches suggest a modest, if any, causal effect of serum uric acid concentration on the development of cardiovascular disease, suggesting that further study of uric acid genes is needed in order to elucidate the relationship of serum uric acid levels and cardiovascular disease.

The challenge of Mendelian randomization approach

This review deals with methodological problems in current evidence that suggest links between gout and adverse cardiovascular (CV) outcomes and renal disease, and presents a recently adopted approach aimed at overcoming such drawbacks. The review aims to provide more reliable answers regarding the role of uric acid in the pathogenesis and progression of cardiovascular and renal events.

Serum uric acid is not independently associated with plasma renin activity and plasma aldosterone in hypertensive adults

BACKGROUND AND AIMS

In experimental investigations conducted in rats, raising serum uric acid (SUA) levels resulted in the stimulation of intrarenal renin expression. Studies in humans exploring the association of SUA with plasma renin activity (PRA) yielded conflicting results. Moreover, little is known about the relationship of SUA with plasma aldosterone concentration (PAC). The study aimed to assess the relationship between SUA levels, PRA, and PAC and the influence of age, gender, body mass index (BMI), and hyperuricemia on these relationships in subjects with essential hypertension (EH).

METHODS AND RESULTS

We enrolled 372 hypertensive patients (mean age 45 ± 12 years, men 67%) with uncomplicated EH that was not pharmacologically treated. The study population was divided in tertiles according to SUA levels. While PRA did not differ significantly across the three tertiles, PAC was higher in subjects belonging to the uppermost tertile of SUA than those in the lower ones (p = 0.0429); however, this difference lost statistical significance after adjustment for age, sex, BMI, and serum creatinine. Univariate correlation analyses showed significant associations of SUA with PRA (r = 0.137; p = 0.008) and PAC (r = 0.179; p < 0.001). However, these relationships were not significant after correcting for confounding factors in multiple linear regression analyses. We did not observe statistically significant effect modification by gender, age, BMI, and hyperuricemia.

CONCLUSION

SUA levels are weakly associated with PRA and PAC in adults with untreated EH. These relationships were lost after adjustment for age, sex, BMI, and serum creatinine.

[Chronic kidney disease and dyslipidaemia]

Chronic kidney disease (CKD) has to be considered as a high, or even very high risk cardiovascular risk condition, since it leads to an increase in cardiovascular mortality that continues to increase as the disease progresses. An early diagnosis of CKD is required, together with an adequate identification of the risk factors, in order to slow down its progression to more severe states, prevent complications, and to delay, whenever possible, the need for renal replacement therapy. Dyslipidaemia is a factor of the progression of CKD that increases the risk in developing atherosclerosis and its complications. Its proper control contributes to reducing the elevated cardiovascular morbidity and mortality presented by these patients. In this review, an assessment is made of the lipid-lowering therapeutic measures required to achieve to recommended objectives, by adjusting the treatment to the progression of the disease and to the characteristics of the patient. In CKD, it seems that an early and intensive intervention of the dyslipidaemia is a priority before there is a significant decrease in kidney function. Treatment with statins has been shown to be safe and effective in decreasing LDL-Cholesterol, and in the reduction of cardiovascular events in individuals with CKD, or after renal transplant, although there is less evidence in the case of dialysed patients.