Hyperuricemia and coronary heart disease: a systematic review and meta-analysis

Effıcacy and safety of dapagliflozin on diabetic patients receiving high-doses of insulin

OBJECTIVE

In this study we aimed to investigate the efficacy and safety of dapagliflozin addition to diabetic patients using high dose insulin.

METHODS

The current study was carried out in the outpatient diabetic clinics of Fatih Sultan Mehmet Education and Research Hospital. Thirty diabetic patients who were receiving high dose (>0,5U/kg) insulin and oral antidiabetic treatment (other than SGLT 2 inhibitors) were included in this study. Primary end point was the change in HbA1c, insulin doses and serum electrolyte from the addition of dapagliflozin 10 mg to the week 12.

RESULTS

At the end of three month BMI were obviously decreased from 33.31 ±4.51 to 32.14 ±4.66 (p: 0.001). There was also an evident decrease of insulin requirement from 76 ±23.15 U/kg to 57.60 ±17.61 U/day (p<0.001). As well as the decrease in insulin doses, there was also a significant decline in HbA1c (Δ 1.6 %) and fasting blood glucose levels (Δ68.6 mg/dl) (p<0.001). Among serum electrolyte levels slight but meaningful increase of blood urea nitrogen (BUN) and sodium (Na) levels were seen (p: 0.044 and p: 0.026). There were no significant changes in serum cholesterol levels with electrolytes such as potassium, calcium, phosphorus magnesium and vitamin D (p> 0.05).

CONCLUSION

In diabetic patients with inadequately controlled glucose regulation despite high-dose insulin therapy, dapagliflozin may be an alternative combination choice to decrease the need of insulin dose and obtain an optimal HbA1c, fasting plasma glucose levels and weight without major side effects.

Effects of sodium glucose cotransporter-2 inhibitors on serum uric acid in type 2 diabetes mellitus: A systematic review with an indirect comparison meta-analysis

To describe the effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on serum uric acid (SUA) in patients with type 2 diabetes mellitus (T2DM). PubMed, EMBASE, and CENTRAL were searched for randomized controlled trials of SGLT2 inhibitors in patients with T2DM up to Aug 10, 2017, without language or date restrictions. Thirty-one studies totaling 13,650 patients were included. SGLT2 inhibitors significantly decreased SUA levels compared with placebo, canagliflozin WMD -37.02 μmol/L, 95% CI [-38.41, -35.63], dapagliflozin WMD -38.05 μmol/L, 95% CI [-44.47, -31.62], empagliflozin WMD -42.07 μmol/L, 95% CI [-46.27, -37.86]. The drug class effect of SUA reduction suggesting SGLT2 inhibitors might be beneficial for diabetic patients with hyperuricemia.

The association between gout and cardiovascular disease in patients with atrial fibrillation

Objective

Gout is a sign of a disturbed metabolism and associated with atrial fibrillation (AF) and other cardio-vascular diseases. Our aim was to study associations between gout and cardiovascular co-morbidities in patients with AF.

Methods

The study population included all adults (n=12,283) ≥45 years diagnosed with AF visiting 75 primary care centers in Sweden 2001-2007. Logistic regression was used to calculate odds ratios with 95% confidence intervals (CIs) for the associations between prevalent gout and cardiovascular co-morbidities. In subsamples we studied incident congestive heart failure (CHF) and ischemic stroke (IS), excluding patients with earlier registered specific diagnosis, using Cox regression (to estimate hazard ratios (HR) with 95% CIs).

Results

Gout was significantly and positively associated with CHF, obesity and diabetes among men and women, and among men also with hypertension and coronary heart disease. Prevalent gout was negatively associated with incident IS (HR and 95% CI: 0.64, 0.49-0.82; 0.50, 0.39-0.64) in both full model (adjusted for sex, age, socio-economic factors and comorbidities) and CHA₂DS₂-VASc model (adjusted for CHA₂DS₂-VASc, sex and age). Adding gout to full model increased Harrell's C by 1% in CHA₂DS₂-VASc model.

Conclusions

In this clinical setting we found gout to be associated with most cardiometabolic diseases except cerebrovascular diseases, and with decreased risk of IS, with gout adding significantly to the predictive value compared to CHA₂DS₂-VASc without gout included.

Serum uric acid and cardiovascular mortality in chronic kidney disease: a meta-analysis

Background

Conflicting results have been reported from studies evaluating serum uric acid (SUA) levels as an independent risk factor for cardiovascular mortality in patients with chronic kidney disease (CKD).

Methods

We systematically searched MEDLINE, Web of Science, and bibliographies of retrieved articles to identify studies reporting on the association between SUA levels and cardiovascular mortality in patients with CKD. Random-effects models were used to calculate the pooled hazard ratios (HR) and corresponding 95% confidence intervals (CI).

Results

We included 11 studies with an overall sample of 27,081 patients with CKD in this meta-analysis. By meta-analysis, restricted to 7 studies (n = 11,050), patients with the highest SUA were associated with an increased risk of cardiovascular mortality (HR 1.47, 95% CI 1.11–1.96) compared with patients with the lowest SUA. There was no indication of publication bias or significant heterogeneity (I² = 40.4%; P = 0.109). Meta-analysis of 10 studies (n = 26,660) indicated that every 1 mg/dl increase in SUA levels increased a 12% risk in cardiovascular mortality (HR 1.12, 95% CI 1.02–1.24), with significant heterogeneity (I² = 79.2%, P < 0.001).

Conclusions

Higher SUA levels are associated with significantly increased risk of cardiovascular mortality in patients with CKD. More designed studies, especially randomized controlled trials, should be conducted to determine whether high SUA levels is a potentially modifiable risk factor for cardiovascular mortality in patients with CKD.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1143-7) contains supplementary material, which is available to authorized users.

Dynamic changes in purine catabolism in patients with acute coronary syndrome that underwent percutaneous coronary intervention

BACKGROUND

Cardiovascular diseases are global problems. They are causes of death in about 43% of people worldwide and may become the most widespread reason of death by 2020. The prognosis is directly dependent to immediate diagnosis and on time treatment. Introduction of new biochemical markers as the early diagnosis of complications after coronary revascularization is very important in this period. Herein, we assayed the changes of purine catabolites in patients with acute coronary syndrome (ACS) before and after percutaneous coronary intervention (PCI) in comparison with control group.

METHODS

Thirty five ACS patients (20 males and 15 females) were included (57±17 years old) in the study. The determination of intermediates of purine catabolism as guanine, hypoxanthine (GCS), adenine, xanthine (Kc) and uric acid (MK) were assayed before and 3 days after PCI. Conditionally, 35 healthy-matched persons were included in the control group. Purine catabolites were determined in plasma through the method of Oreshnikov E.V (2008).

RESULTS

In ACS patients, prior to PCI, there was a tendency to increase the concentration of guanine (P=0.001), hypoxanthine (P=0.002) adenine (P=0.0003), xanthine (P=0.000003) and uric acid (P=-0.000001) relative to the upper limits of normal ranges. And on the third day after PCI, there was the second tendency to increase the levels of guanine (P=0.000001), hypoxanthine (P=0.000001) adenine (P=0.0000001), xanthine (P=0.000001) and uric acid (P=0.0000001) relative to upper limits of normal ranges.

CONCLUSION

Increment of plasma purine catabolites can be a marker of inflammation and instability of coronary artery plaques and may be used as a restenosis marker in patients with history of PCI.

Effects of dapagliflozin on serum uric acid levels in hospitalized type 2 diabetic patients with inadequate glycemic control: a randomized controlled trial

Background

Raised serum uric acid (SUA) level is commonly observed in patients with type 2 diabetes mellitus (T2DM) and is associated with increased morbidity and mortality. Sodium-glucose cotransporter 2 inhibitor, a novel oral diabetic drug, might exert a potential hypouricemic effect. We evaluated the effects of dapagliflozin on SUA levels in hospitalized T2DM patients with inadequate glycemic control.

Methods

In this randomized controlled trial, 59 T2DM hospitalized patients with inadequate glycemic control were assigned to the dapagliflozin 10 mg group (n=29) or the control group (n=30). The primary outcome was changes in SUA levels from the baseline to good glycemic control. Additional outcomes included correlations between baseline SUA levels, urinary parameters, and the changes in SUA levels. This trial is registered in the Chinese Clinical Trial Registry (number ChiCTR1800015830).

Results

Compared to baseline level, SUA levels had significantly decreased in both groups (P<0.001 for the dapagliflozin group and P=0.013 for the control group). Mean changes from baseline in SUA levels for dapagliflozin vs the control group were 68.03 vs 25.90 μmol/L (P=0.0406). Adjusted mean SUA levels were lower in the dapagliflozin group (273.28 vs 307.57 μmol/L; P=0.0089). In T2DM patients treated with dapagliflozin, the decrease in SUA levels was positively correlated with baseline SUA levels (P<0.0001) but not correlated with changes in 24-hour urine volume, 24-hour urine glucose, or 24-hour urinary uric acid.

Conclusion

Dapagliflozin could improve glycemic control and lower SUA levels in hospitalized patients with uncontrolled T2DM. Longer-time trials are required to further demonstrate the hypouricemic effect of dapagliflozin and explore the potential underlying mechanisms.

White blood cell count: an independent predictor of coronary heart disease risk in middle-aged and elderly population with hyperuricemia

Previous studies have shown that hyperuricemia is an independent risk factor for cardiovascular disease. The aim of the study was to examine the association between white blood cell (WBC) count and coronary heart disease (CHD) risk in middle-aged and elderly population with hyperuricemia.Data included in this analysis were from a population-based cross-sectional study, that is, the Xiangya Hospital Health Management Center Study. Hyperuricemia was defined as uric acid ≥416 μmol/L in male population and ≥360 μmol/L in female population. The WBC count was classified into 3 categories based on the tertile distribution of the study population. Framingham risk scores calculated by the Adult Treatment Panel III charts were used to estimate 10-year CHD risk for each participant. The relationship between WBC count and CHD risk in patients with hyperuricemia was examined using the multivariable logistic analysis.A total of 1148 hyperuricemia patients (855 males and 293 females) aged from 40 to 85 years were included and 418 (36.4%) of them were defined with relatively high 10-year CHD risk. Compared with the lowest tertile, the crude odds ratios (ORs) of high 10-year CHD risk were 1.43 (95% confidence interval [CI] 1.06-1.92) and 1.56 (95% CI 1.16-2.11) in the 2nd and 3rd tertiles of WBC count (P for trend = .004), and the multivariable adjusted ORs of high 10-year CHD risk were 1.39 (95% CI 1.03-1.89) and 1.47 (95% CI 1.08-2.00) in the 2nd and 3rd tertiles of WBC count (P for trend = .015).This study indicated that WBC count was associated with CHD risk in patients with hyperuricemia, suggesting that WBC count, an easily accessible biomarker, could probably predict CHD risk in middle-aged and elderly population with hyperuricemia.

Gout and dementia in the elderly: a cohort study of Medicare claims

Background

Conflicting data in the literature raise the question whether gout, independent of its treatment, increases the risk of dementia in the elderly. Our objective was to assess whether gout in older adults is associated with the risk of incident dementia.

Methods

We used the 5% Medicare claims data for this observational cohort study. We used multivariable-adjusted Cox proportional hazard models to assess the association of gout with a new diagnosis of dementia (incident dementia), adjusting for potential confounders/covariates including demographics (age, race, sex), comorbidities (Charlson-Romano comorbidity index), and medications commonly used for cardiac diseases (statins, beta-blockers, diuretics, and angiotensin converting enzyme (ACE)-inhibitors) and gout (allopurinol and febuxostat).

Results

In our cohort of 1.71 million Medicare beneficiaries, 111,656 had incident dementia. The crude incidence rates of dementia in people without and with gout were 10.9 and 17.9 per 1000 person-years, respectively. In multivariable-adjusted analyses, gout was independently associated with a significantly higher hazard ratio of incident dementia, with a HR of 1.15 (95% CI, 1.12, 1.18); sensitivity analyses confirmed the main findings. Compared to age 65 to < 75 years, age 75 to < 85 and ≥ 85 years were associated with 3.5 and 7.8-fold higher hazards of dementia; hazards were also higher for females, black race or people with higher medical comorbidity.

Conclusion

Gout was independently associated with a 15% higher risk of incident dementia in the elderly. Future studies need to understand the pathogenic pathways involved in this increased risk.

Gender-Related Association of Serum Uric Acid Levels with Premature Ventricular Contraction

In this study, we aim to investigate the association of serum uric acid (SUA) with the prevalence of premature ventricular contraction (PVC). The relationship between SUA and the prevalence of PVC in 98,965 subjects (79,034 male subjects, mean age: 51.9 ± 12.6 years old) in the Kailuan cohort study (n = 101,510, age range: 18-98 years) from June 2006 to October 2007 was investigated. These subjects were divided into five groups on the basis of their SUA levels. A multivariate logistic regression model was constructed to evaluate the association between SUA and the prevalence of PVC. The prevalence of PVC was 1.1% in all subjects, 1.1% in male subjects, and 1.0% in female subjects. Compared with the first quintile of SUA, the odds ratio (OR) and 95% confidence interval (95% CI) of other quintiles were 1.33 (1.05-1.69), 1.14 (0.90-1.46), 1.37 (1.08-1.74), and 1.63 (1.30-2.06) in male subjects; 1.12 (0.68-1.87), 1.27 (0.77-2.09), 1.45 (0.90-2.36), and 1.33 (0.81-2.18) in female subjects; and 1.30 (1.04-1.61), 1.20 (0.96-1.50), 1.33 (1.07-1.66), and 1.57 (1.26-1.95) for all subjects. The correlation between SUA and the prevalence of PVC was significant in all subjects and in male subjects, but not in female subjects. We demonstrated that SUA was apparently associated with the prevalence of PVC. The significant relationship between SUA and PVC identified in male subjects suggests the potential involvement of a gender-specific mechanism. Prospective studies are needed to further corroborate our results.

Uric Acid Level and New-Onset Atrial Fibrillation in the Japanese General Population - Longitudinal Study

BACKGROUND

The independent role of uric acid (UA) as a risk factor for atrial fibrillation (AF) has not been fully elucidated. Methods and Results: We studied 111,566 subjects (53,416 men; 58,150 women) who underwent annual health check-ups. We divided them by sex into tertile of baseline UA. To investigate the predictive power of UA for new-onset AF, we performed Cox proportional hazard analysis including UA tertiles, body mass index, creatinine, smoking and drinking status, and presence of hypertension, diabetes, and dyslipidemia. During 4.1 years, 467 men (0.87%) and 180 women (0.31%) had AF (P<0.001). Cut-off points for tertiles of UA were as follows: women, ≤3.9, 4.0-4.8, and ≥4.9 mg/dL; men, ≤5.4, 5.5-6.4, and ≥6.5 mg/dL. Hazard ratio (HR) for third to first tertile was 1.74 (95% CI: 1.15-2.70; P=0.008), whereas there were no differences between tertiles in men. Rate of new-onset AF was significantly higher in the group with initially increased UA (ΔUA ≥0.3 mg/dL) than that with unchanged UA (ΔUA, -0.2 or +0.2 mg/dL) in the third tertile of baseline UA in both sexes.

CONCLUSIONS

Higher baseline UA was significantly associated with higher AF incidence in women. Initial increase in UA was significantly associated with AF incidence when baseline UA was ≥6.5 mg/dL in men, and ≥4.9 mg/dL in women.

Comprehensive analysis of predictive factors for rapid angiographic stenotic progression and restenosis risk in coronary artery disease patients underwent percutaneous coronary intervention with drug-eluting stents implantation

BACKGROUND

This study aimed to explore the correlation of baseline, procedural, and postprocedure characteristics with the risk of rapid angiographic stenotic progression (RASP) and restenosis in coronary artery disease (CAD) patients after percutaneous coronary intervention (PCI) with drug-eluting stents implantation.

METHODS

Two hundred fourteen CAD patients underwent PCI with drug-eluting stents implantation were consecutively enrolled. Baseline, procedural, and postprocedure characteristics of patients were collected for analysis. Coronary angiography was performed to evaluate coronary stenosis before PCI and at 12 months after PCI. RASP of nontarget lesions and restenosis of stent-implanted target lesions were then assessed.

RESULTS

37.8% CAD patients occurred RASP at 12 months after PCI and compared to non-RASP group, RASP group presented with increased diabetes mellitus (DM) complication, higher concentration of serum uric acid (SUA), cardiac troponin I, N-terminal probrain natriuretic peptide, and high sensitive C-reactive protein (hs-CRP) as well as elevated occurrence of multivessel artery lesions. In addition, DM, SUA, hs-CRP, and multivessel artery lesions independently predicted high RASP risk. For restenosis, 21.0% patients occurred restenosis at 12 months after PCI, and patients in restenosis group presented with increased hypertension and DM occurrence, higher concentrations of SUA, LDL-C, and hs-CRP, as well as longer target lesion and length of stent in surgery compared to nonrestenosis group. Also, DM, SUA, LDL-C, hs-CRP, and length of target lesion independently predicted increased restenosis risk.

CONCLUSION

Diabetes mellitus, SUA, and hs-CRP are potential predictive factors for increased risk of both RASP and restenosis in CAD patients underwent PCI and drug-eluting stents implantation.

Risk factors for hyperuricemia in congenital heart disease patients and its relation to cardiovascular death

INTRODUCTION

Hyperuricemia has been associated with cardiovascular risk factors but it remains controversial if uric acid is an independent predictor of cardiac mortality.

METHODS

A total of 503 CHD patients (457 nonhypoxemic and 46 hypoxemic) and 772 control patients fulfilled inclusion criteria. Demographic, clinical, and analytical data [serum uric acid and 24h urine uric acid levels, N-terminal pro-B-type natriuretic peptide (NT-pro-BNP), and C-reactive-protein (CRP) concentrations] were studied. Survivals curves to determine cardiac death and arterial thrombosis in CHD patients were also examined.

RESULTS

Noncyanotic and cyanotic CHD patients had significant higher serum uric acid concentration (5.2 ± 1.5 vs 4.9 ± 1.3mg/dL, P = .007 and 6.7 ± 2.1 vs 4.9 ± 1.3mg/dL, P < .001, respectively) and gout (1% vs 0%, P = .003 and 4% vs 0%, P < .01, respectively) than the control population. Among CHD patients, hyperuricemic patients were significant older and with overweight, used more diuretics, were more cyanotic and had higher serum creatinine, NT-pro-BNP and CRP concentrations than nonhyperuricemic. In the multivariable analysis, the body mass index (BMI) (OR 1.09; 95% CI 1.01-1.18), cyanosis (OR 6.2; 95 CI 1.5-24.6), serum creatinine concentration (OR 49; 95% CI 44-538), and being under diuretic treatment (OR 4.5; 95% CI 1.4-14.5) proved to be risk factors for hyperuricemia in CHD patients. The Kaplan-Meier events free survival curves, during a 5.2 ± 2.7 years follow-up of up time, showed that hyperuricemic CHD patients had significant higher cardiovascular death (P = .002). However, after applying the Cox regression analysis uric acid levels lost its statistical significance. No significant differences were seen in relation to thrombotic events between CHD patients with and without hyperuricemia.

CONCLUSIONS

CHD patients, noncyanotic and cyanotic, have higher serum uric acid levels and gout than patients in the general population. BMI, renal insufficiency, cyanosis, and the use of diuretics were risk factor for hyperuricemia among CHD patients.

Gout and the risk of incident atrial fibrillation in older adults: a study of US Medicare data

Objective

To assess the association of gout with new-onset atrial fibrillation (AF) in the elderly.

Methods

We used the 5% Medicare data from 2005 to 2012 to assess whether a diagnosis of gout was associated with incident AF. We used multivariable Cox regression adjusted for demographics, Charlson-Romano comorbidity index, common cardiovascular medications, allopurinol and febuxostat use, to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

Among 1 647 812 eligible people, 9.8% had incident AF. The mean age was 75 years, 42% were male, 86% were white and the mean Charlson-Romano index score was 1.52. We noted 10 604 incident AF cases in people with gout and 150 486 incident AF cases in people without gout. The crude incidence rates of AF in people with and without gout were 43.4 vs 16.3 per 1000 patient-years, respectively. After multivariable-adjustment, gout was associated with a higher HR of incident AF, 1.92 (95% CI 1.88 to 1.96), with minimal attenuation of HR in sensitivity models that replaced the Charlson-Romano index score with a categorical variable, HR was 1.91 (95% CI 1.87 to 1.95). In another model that adjusted for AF-specific risk factors including hypertension, hyperlipidaemia and coronary artery disease and individual Charlson-Romano index comorbidities, the HR was slightly attenuated at 1.71 (95% CI 1.67 to 1.75). Older age, male sex, white race and higher Charlson-Romano index score were each associated with higher hazard of incident AF.

Conclusion

A diagnosis of gout almost doubled the risk of incident AF in the elderly. Future studies should explore the pathogenesis of this association.

Asymptomatic hyperuricemia and coronary flow reserve in patients with metabolic syndrome

Background

Patients with metabolic syndrome (MetS) are at increased risk of asymptomatic hyperuricemia (i.e., elevated serum uric acid (SUA) level without gout) and cardiovascular disease. We conducted a cross-sectional study to examine associations between SUA levels and coronary flow reserve and urate deposits in carotid arteries in patients with asymptomatic hyperuricemia and MetS.

Methods

Adults aged ≥40 years with MetS and SUA levels ≥6.5 mg/dl, but no gout, were eligible. Using a stress myocardial perfusion positron emission tomography (PET), we assessed myocardial blood flow (MBF) at rest and stress and calculated coronary flow reserve (CFR). CFR < 2.0 is considered abnormal and associated with increased cardiovascular risk. We also measured insulin resistance by homeostatic model assessment (HOMA-IR) method and urate deposits using dual-energy CT (DECT) of the neck for the carotid arteries.

Results

Forty-four patients with the median age of 63.5 years underwent a blood test, cardiac PET and neck DECT scans. Median (IQR) SUA was 7.8 (7.1-8.4) mg/dL. The median (IQR) CFR was abnormally low at 1.9 (1.7-2.4) and the median (IQR) stress MBF was 1.7 (1.3-2.2) ml/min/g. None had urate deposits in the carotid arteries detected by DECT. In multivariable linear regression analyses, SUA had no association with CFR (β = - 0.12, p = 0.78) or stress MBF (β = - 0.52, p = 0.28). Among non-diabetic patients (n = 25), SUA was not associated with HOMA-IR (β = 2.08, p = 0.10).

Conclusions

Among MetS patients with asymptomatic hyperuricemia, we found no relationship between SUA and CFR, stress MBF, and insulin resistance. No patients had any DECT detectable subclinical urate deposition in the carotid arteries.

Uric acid and obesity-related phenotypes in postmenopausal women

The aim of this study was to find the genetic, metabolic, and nutritional risk factors, which can be associated with uric acid (UA) level. The risk factors related to uricemia were assessed among 271 postmenopausal women without cardiometabolic disorders and hypolipidemic/hypoglycemic treatment selected from a cohort of 1423 obese postmenopausal women. The bioimpedance analysis and biochemical and genetic analyses were performed in two groups characterized by serum UA ≥ 4 mg/dL (238 μmol/L) and < 4 mg/dL. The TaqMan-based real-time PCR method was applied to assess the role of Pro12Ala of peroxisome proliferation-activated receptor (PPAR)gamma-2 and Trp64Arg of beta-3-adrenergic receptor (ADRB) polymorphisms. Women with UA level ≥ 4 mg/dL were characterized by larger body mass, triceps skinfold, waist circumference, body fat amount, and serum insulin, glucose, and triglyceride levels. There was no difference in dietary habits between the analyzed groups. Body mass, waist circumference, body fat amount, diastolic blood pressure, and serum insulin, glucose, high-density lipoprotein, and triglyceride levels, Homeostasis Model Assessment-Insulin Resistance, and energy from the dietary fat influence the UA level ≥ 4 mg/dL; however, the serum UA was not determined by Pro12Ala and Trp64Arg polymorphism analyses. The model of linear regression revealed that the group characterized by body mass index  ≥ 25 kg/m2 and glucose ≥ 100 mg/dL has 4 times increased risk of UA level (p = 0.0009); after adding triglycerides ≥ 150 mg/dL, the risk of UA increased 7 times (p = 0.0216). Increasing the level of UA ≥ 4 mg/dL is associated with overweight, hyperglycemia, and hypertriglyceridemia in women without a history of cardiometabolic disorders. A better management of metabolic factors could help prevent further increase in UA levels.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

Physiology of Hyperuricemia and Urate-Lowering Treatments

Gout is the most common form of inflammatory arthritis and is a multifactorial disease typically characterized by hyperuricemia and monosodium urate crystal deposition predominantly in, but not limited to, the joints and the urinary tract. The prevalence of gout and hyperuricemia has increased in developed countries over the past two decades and research into the area has become progressively more active. We review the current field of knowledge with emphasis on active areas of hyperuricemia research including the underlying physiology, genetics and epidemiology, with a focus on studies which suggest association of hyperuricemia with common comorbidities including cardiovascular disease, renal insufficiency, metabolic syndrome and diabetes. Finally, we discuss current therapies and emerging drug discovery efforts aimed at delivering an optimized clinical treatment strategy.

Temporal trends in hyperuricaemia in the Irish health system from 2006-2014: A cohort study

Background

Elevated serum uric acid (sUA) concentrations are common in the general population and are associated with chronic metabolic conditions and adverse clinical outcomes. We evaluated secular trends in the burden of hyperuricaemia from 2006–2014 within the Irish health system.

Methods

Data from the National Kidney Disease Surveillance Programme was used to determine the prevalence of elevated sUA in adults, age > 18 years, within the Irish health system. Hyperuricaemia was defined as sUA > 416.4 μmol/L in men and > 339.06 μmol/L in women, and prevalence was calculated as the proportion of patients per year with mean sUA levels above sex-specific thresholds. Temporal trends in prevalence were compared from 2006 to 2014 while general estimating equations (GEE) explored variation across calendar years expressed as odds ratios (OR) and 95% Confidence intervals (CI).

Results

From 2006 to 2014, prevalence of hyperuricaemia increased from 19.7% to 25.0% in men and from 20.5% to 24.1% in women, P<0.001. The corresponding sUA concentrations increased significantly from 314.6 (93.9) in 2006 to 325.6 (96.2) in 2014, P<0.001. Age-specific prevalence increased in all groups from 2006 to 2014, and the magnitude of increase was similar for each age category. Adjusting for baseline demographic characteristics and illness indicators, the likelihood of hyperuricemia was greatest for patients in 2014; OR 1.45 (1.26–1.65) for men and OR 1.47 (1.29–1.67) in women vs 2006 (referent). Factors associated with hyperuricaemia included: worsening kidney function, elevated white cell count, raised serum phosphate and calcium levels, elevated total protein and higher haemoglobin concentrations, all P<0.001.

Conclusions

The burden of hyperuricaemia is substantial in the Irish health system and has increased in frequency over the past decade. Advancing age, poorer kidney function, measures of nutrition and inflammation, and regional variation all contribute to increasing prevalence, but these do not fully explain emerging trends.

Medication Regimen Complexity Measured by MRCI: A Systematic Review to Identify Health Outcomes

Objective: To perform a systematic review to identify health outcomes related to medication regimen complexity as measured by the Medication Regimen Complexity Index (MRCI) instrument. Data Sources: Cochrane Library, LILACS, PubMed, Scopus, EMBASE, Open Thesis, and Web of Science were searched from January 1, 2004, until April 02, 2018, using the following search terms: outcome assessment, drug therapy, and Medication Regimen Complexity Index and their synonyms in different combinations. Study Selection and Data Extraction: Studies that used the MRCI instrument to measure medication regimen complexity and related it to clinical, humanistic, and/or economic outcomes were evaluated. Two reviewers independently carried out the analysis of the titles, abstracts, and complete texts according to the eligibility criteria, performed data extraction, and evaluated study quality. Data Synthesis: A total of 23 studies met the inclusion criteria; 18 health outcomes related to medication regimen complexity were found. The health outcomes most influenced by medication regimen complexity were hospital readmission, medication adherence, hospitalization, adverse drug events, and emergency sector visit. Only one study related medication regimen complexity with humanistic outcomes, and no study related medication regimen complexity to economic outcomes. Most of the studies were of good methodological quality. Relevance to Patient Care and Clinical Practice: Health care professionals should pay attention to medication regimen complexity of the patients because this may influence health outcomes. Conclusion: This study identified some health outcomes that may be influenced by medication regimen complexity: hospitalization, hospital readmission, and medication adherence were more prevalent, showing a significant association between MRCI increase and these health outcomes.

Uric acid levels are associated with endothelial dysfunction and severity of coronary atherosclerosis during a first episode of acute coronary syndrome

The role of serum uric acid in coronary artery disease has been extensively investigated. It was suggested that serum uric acid level (SUA) is an independent predictor of endothelial dysfunction and related to coronary artery lesions. However, the relationship between SUA and severity of coronary atherosclerosis evaluated via endothelial dysfunction using peripheral arterial tone (PAT) and the reactive hyperhemia index (RHI) has not been investigated during a first episode of acute coronary syndrome (ACS). The aim of our study was to address this point. We prospectively enrolled 80 patients with a first episode of ACS in a single-center observational study. All patients underwent coronary angiography, evaluation of endothelial function via the RHI, and SUA measurement. The severity of the coronary artery lesion was assessed angiographically, and patients were classified in three groups based on the extent of disease and Gensini and SYNTAX scores. Endothelial function was considered abnormal if RHI < 1.67. We identified a linear correlation between SUA and RHI (R² = 0.66 P < 0.001). In multivariable analyses, SUA remained associated with RHI, even after adjustment for traditional cardiovascular risk factors and renal function. SUA was associated with severity of coronary artery disease. SUA is associated with severity of coronary atherosclerosis in patients with asymptomatic hyperuricemia. This inexpensive, readily measured biological parameter may be useful to monitor ACS patients.

High serum uric acid levels may increase mortality and major adverse cardiovascular events in patients with acute myocardial infarction

Objectives:

To determine the validity of uric acid as a potential prognostic marker for long-term outcomes of patients with acute myocardial infarction (AMI) and those with AMI undergoing percutaneous coronary intervention (PCI).

Methods:

Systematic review and meta-analysis were performed. We retrieved data from retrospective and prospective cohort studies that investigated whether serum uric acid (SUA) level affects the prognosis of patients with AMI.

Results:

Thirteen studies involving 9371 patients were included. High serum uric acid (HSUA) level increased mid/long-term mortality (risk ratio (RR)=2.32, 95% confidence intervals (CI): 2.00–2.70) and had higher short-term mortality (RR=3.09, 95% CI: 2.58–3.71), higher mid/long-term major adverse cardiovascular events (MACE) risk (RR=1.70, 95% CI: 1.54–1.88), and higher short-term MACE risk (RR=2.47, 95% CI: 2.08–2.92) for patients with AMI. In the PCI subgroup, the HSUA level also increased mid/long-term mortality (RR=2.33, 95% CI: 1.89 to 2.87) and had higher mid/long-term MACE risk (RR=1.64, 95% CI: 1.48–1.82), and higher short-term MACE risk (RR 2.43, 95% CI: 2.02–2.93) for patients who were treated with PCI after AMI. Particularly in the PCI subgroup, a higher short-term mortality (RR=6.70, 95% CI: 3.14–14.31) was presented in the group with lower HSUA cut-off level, and the mortality was higher than the group with higher HSUA cut-off level (RR=2.69, 95% CI: 2.09–3.46).

Conclusion:

The HSUA level significantly increased the mortality and MACE risk of patients with AMI. Mild elevation of SUA levels (normal range) have started to have a significant impact on the short-term mortality of patients who underwent PCI, and has not received the attention of previous studies. However, this condition should be further investigated.

Prevalence and correlates of hyperuricemia in the middle-aged and older adults in China

Hyperuricemia, the physiological prerequisite for gout, is linked to the presence and severity of multiple comorbidities that affect longevity and well-being. By using the baseline data from the China Health and Retirement Longitudinal Study, a nationally representative survey, the prevalence of hyperuricemia in general middle-aged and older Chinese was estimated. The potential effects of health behaviours and comorbidities on hyperuricemia were also explored. In 2010, the prevalence of hyperuricemia among middle-aged and older Chinese was 6.4%. Hyperuricemia was more prevalent in males than in females (7.9% vs. 4.9%). The risk of hyperuricemia increased with advanced age in both sexes. In males, current drinking, obesity and dyslipidemia were positively associated with hyperuricemia, whereas singles males and males living in North China were with lower odds of having hyperuricemia. For females, being single, at a higher economic level, living in the Southwest China, smoking, obesity, diabetes, hypertension and dyslipidemia were all significant risk factors for hyperuricemia, but females living in North China and Northwest China were with a lower hyperuricemia prevalence than females in East China. Therefore, hyperuricemia in China was not as prevalent as in developed countries, its prevalence varied greatly according to demographic, socioeconomic, and geographic factors.

Hyperuricemia and severity of coronary artery disease: An observational study in adults 35 years of age and younger with acute coronary syndrome

BACKGROUND

Coronary artery disease (CAD) in adults ≤ 35 years of age is rare, but the incidence is on the rise and the risk factors for this age group are largely uncertain. Previous studies have shown that hyperuricemia (HUA) is an independent risk factor for CAD in the general population, whereas the role in adults ≤ 35 years of age with acute coronary syndrome (ACS) is unclear.

METHODS

Patients, 18-35 years of age, diagnosed with ACS for the first time at the documented institu- tion between January 2005 and December 2015, were enrolled in the current study. The severity of CAD was assessed by the Gensini score. Patients were divided into two groups according to the definition of HUA. The relationship between HUA and CAD severity was assessed based on multi-variate analysis.

RESULTS

Seven hundred seventy-one participants fulfilling the criteria were included in this study (mean age, 31.6 years; 94.4% male). HUA, which was defined as a serum uric acid level ≥ 7.0 mg/dL (420μmol/L) in males and ≥ 6.0 mg/dL (357 μmol/L) in females, accounted for 37% of the participants. Multivariate analysis identified that HUA is an independent risk factor of CAD severity, as assessed by the Gensini score, in very young adults with ACS (OR 8.28; 95% CI 1.96-14.59; p = 0.01), and the effect of HUA on CAD severity was second only to diabetes mellitus.

CONCLUSIONS

Hyperuricemia was shown to be an independent risk factor for CAD severity in young adults with ACS (18-35 years of age).

An evaluation of longitudinal changes in serum uric acid levels and associated risk of cardio-metabolic events and renal function decline in gout

OBJECTIVE

Gout patients have a high burden of co-morbid conditions including diabetes mellitus (DM), chronic kidney disease (CKD), and cardiovascular disease (CVD). We sought to evaluate the association between changes in serum uric acid (SUA) levels over time and the risk of incident DM, CVD, and renal function decline in gout patients.

METHODS

An observational cohort study was conducted among enrollees of private health insurance programs in the US between 2004 and 2015. Gout patients were included on the index date of a SUA measurement ≥6.8 mg/dl. The exposure of interest was cumulative change in SUA levels from baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for incident DM, incident CVD, and renal function decline (≥30% reduction in glomerular filtration rate) were derived using marginal structural models with stabilized inverse probability weights accounting for baseline confounders (age, gender, co-morbidities, co-medications) and time-varying confounders (serum creatinine, blood urea nitrogen, glycated hemoglobin).

RESULTS

Among 26,341 patients with gout, the average age was 62, 75% were men, and the median baseline SUA was 8.6 mg/dl (interquartile range 7.7 to 9.5). The incidence rates/100 person-years (95% CI) were 1.63 (1.51-1.75) for DM, 0.77 (0.70-0.84) for CVD, and 4.32 (4.14-4.49) for renal function decline. The adjusted HR (95% CI) per 3 mg/dl reduction in SUA, corresponding on average to achieving the target level of <6 mg/dl in this population, was 1.04 (0.92-1.17) for DM, 1.07 (0.89-1.29) for CVD, and 0.85 (0.78-0.92) for renal function decline.

CONCLUSIONS

Reduction in SUA in patients with gout may be associated with a reduced risk of renal function decline, but not with DM or CVD.

Hyperuricemia, Acute and Chronic Kidney Disease, Hypertension, and Cardiovascular Disease: Report of a Scientific Workshop Organized by the National Kidney Foundation

Urate is a cause of gout, kidney stones, and acute kidney injury from tumor lysis syndrome, but its relationship to kidney disease, cardiovascular disease, and diabetes remains controversial. A scientific workshop organized by the National Kidney Foundation was held in September 2016 to review current evidence. Cell culture studies and animal models suggest that elevated serum urate concentrations can contribute to kidney disease, hypertension, and metabolic syndrome. Epidemiologic evidence also supports elevated serum urate concentrations as a risk factor for the development of kidney disease, hypertension, and diabetes, but differences in methodologies and inpacts on serum urate concentrations by even subtle changes in kidney function render conclusions uncertain. Mendelian randomization studies generally do not support a causal role of serum urate in kidney disease, hypertension, or diabetes, although interpretation is complicated by nonhomogeneous populations, a failure to consider environmental interactions, and a lack of understanding of how the genetic polymorphisms affect biological mechanisms related to urate. Although several small clinical trials suggest benefits of urate-lowering therapies on kidney function, blood pressure, and insulin resistance, others have been negative, with many trials having design limitations and insufficient power. Thus, whether uric acid has a causal role in kidney and cardiovascular diseases requires further study.

Assessment of coronary vascular function with cardiac PET in relation to serum uric acid

BACKGROUND

Elevated serum uric acid (SUA) levels have been independently associated with cardiovascular disease. Stress myocardial perfusion positron emission tomography (PET) allows for measurement of absolute myocardial blood flow (MBF) and quantification of global left ventricular coronary flow reserve (CFR). A CFR <2.0 is considered impaired coronary vascular function, and it is associated with increased cardiovascular risk. We evaluated the relationship between SUA and PET-measured markers of coronary vascular function.

METHODS

We studied adults undergoing a stress myocardial perfusion PET on clinical grounds (1/2006-3/2014) who also had ≥1 SUA measurement within 180 days from the PET date. Multivariable linear regression estimated the association between SUA and PET-derived MBF and CFR. We also stratified analyses by diabetes status.

RESULTS

We included 382 patients with mean (SD) age of 68.4 (12.4) years and mean (SD) SUA level of 7.2 (2.6) mg/dl. 36% were female and 29% had gout. Median [IQR] CFR was reduced at 1.6 [1.2, 2.0] and median [IQR] stress MBF was 1.5 [1.1, 2.1] ml/min/g. In the adjusted analysis, SUA was inversely associated with stress MBF (β = -0.14, p = 0.01) but not with CFR. Among patients without diabetes (n = 215), SUA had a negative association with CFR (β = -0.15, p = 0.02) and stress MBF (β = -0.19, p = 0.01) adjusting for age, sex, extent of myocardial scar and ischemia, serum creatinine and gout. In diabetic patients (n = 167), SUA was not associated with either CFR or MBF.

CONCLUSIONS

In this cross-sectional study, higher SUA is modestly associated with worse CFR and stress MBF among patients without diabetes.

Baseline and changes in serum uric acid independently predict glucose control among community-dwelling women

BACKGROUND

Elevated serum uric acid (SUA) levels are associated with glucose control. However, whether baseline and changes in SUA predict long-term follow-up glucose control [e.g., glycated hemoglobin (HbA1c)] remains unclear.

METHODS

The subjects comprised 393 women aged 71 ± 8 years and 279 men aged 71 ± 10 years from a rural village. We have identified participants who underwent a similar examination 11 years prior, and subjects were divided into four groups based on the tertiles of baseline and changes in SUA, and examined the relationship between baseline and changes in SUA, and glucose control evaluated by follow-up HbA1c after 11-years.

RESULTS

In both genders, follow-up SUA were significantly higher in Group 4 (i.e., women: Group 4, baseline SUA ≥ 4.0 mg/dL and changes in SUA ≥ 0.8 mg/dL; men: Group 4, ≥ 5.3 mg/dL and ≥ 0.4 mg/dL) than in the other Groups, but eGFR was significantly lower. Only in women, there were significant differences among the four groups regarding follow-up HbA1c, and follow-up HbA1c was highest in Group 4. In addition, the interaction between baseline and changes in SUA (F = 5.391, p = 0.021) as well as baseline low-density lipoprotein cholesterol (LDL-C) (F = 13.793, p < 0.001), estimated glomerular filtration ratio (F = 10.715, p = 0.001), HbA1c (F = 118.285, p < 0.001), SUA (F = 9.457, p = 0.002), and changes in SUA (F = 7.757, p = 0.006) was a significant and independent determinant of follow-up HbA1c. Multivariate-adjusted follow-up HbA1c (p = 0.002) were significantly higher in Group 4 than the other groups.

CONCLUSIONS

These results suggested that combined assessment of baseline and changes in SUA provides increased information for long-term predictive glucose control, independent of other confounding factors in community-dwelling women.

Is gout a risk equivalent to diabetes for stroke and myocardial infarction? A retrospective claims database study

Background

Gout is a risk factor for cardiovascular disease, but associations with specific cardiovascular outcomes, myocardial infarction (MI), and stroke are unclear. Our objective in the present study was to assess whether gout is as strong a risk factor as diabetes mellitus (DM) for incident MI and incident stroke.

Methods

In this retrospective study, we used U.S. claims data from 2007 to 2010 that included a mix of private and public health plans. Four mutually exclusive cohorts were identified: (1) DM only, (2) gout only, (3) gout and DM, and (4) neither gout nor DM. Outcomes were acute MI or stroke with hospitalization. We compared the age- and sex-specific rates of incident MI and stroke across the four cohorts and assessed multivariable-adjusted HRs.

Results

In this study, 232,592 patients had DM, 71,755 had gout, 23,261 had both, and 1,010,893 had neither. The incidence of acute MI was lowest in patients with neither gout nor DM, followed by patients with gout alone, DM alone, and both. Among men >80 years of age, the respective rates/1000 person-years were 14.6, 25.4, 27.7, and 37.4. Similar trends were noted for stroke and in women. Compared with DM only, gout was associated with a significantly lower adjusted HR of incident MI (HR 0.81, 95% CI 0.76–0.87) but a similar risk of stroke (HR 1.02, 95% CI 0.95–1.10). Compared with patients with DM only, patients with both gout and DM had higher HRs for incident MI and stroke (respectively, HR 1.35, 95% CI 1.25–1.47; HR 1.42, 95% CI 1.29–1.56).

Conclusions

Gout is a risk equivalent to DM for incident stroke but not for incident MI. Having both gout and DM confers incremental risk compared with DM alone for both incident MI and stroke.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1427-5) contains supplementary material, which is available to authorized users.

Asymptomatic hyperuricemia: is it time to intervene?

Whether to treat hyperuricemia uncomplicated by articular gout, urolithiasis, or uric acid nephropathy is an exercise in clinical judgment and universal agreement is lacking. Patients with coronary artery disease, chronic kidney disease, and early onset hypertension with persistent hyperuricemia are likely to be benefited with urate-lowering therapy. The paradigm of the causative association of hyperuricemia with cardiovascular and chronic kidney diseases seems to have progressed from skepticism to increasing evidence of a true relationship. Although such evidences are mounting, they are not enough to support pharmacotherapy for all patients with asymptomatic hyperuricemia. Further studies are needed to determine which patients are likely to get beneficial effects from pharmacotherapy and the minimum threshold of uric acid level required to experience clinical benefits.

Association of serum uric acid level with coronary artery stenosis severity in Korean end-stage renal disease patients

Background

Hyperuricemia is common in end-stage renal disease (ESRD) patients, and many previous studies have reported the associations between hyperuricemia and adverse cardiovascular outcomes, which are the major cause of death in such patients. We investigated the relationship between serum uric acid level and the severity of coronary stenosis in ESRD patients on maintenance hemodialysis (MHD).

Methods

Among 721 patients who started MHD treatment, 102 underwent coronary angiographic tests complaining of chest discomfort that was new at initiation of MHD. We collected data on uric acid level and coronary artery luminal diameter, defining luminal diameter narrowing of more than 50% in any major coronary artery as critical-stenosis.

Results

We detected critical coronary artery stenosis in 52 (57.8%) patients. The mean uric acid level was 6.6 ± 2.2 mg/dL, and that was significantly higher in the critical-stenosis group (4.9 ± 1.4 mg/dL vs. 7.8 ± 2.0 mg/dL, P < 0.001). The only independent predictor of critical-stenosis in multivariate analysis was serum uric acid level (P < 0.001).

Conclusion

High serum uric acid was associated with severe coronary artery stenosis in Korean ESRD patients. Hyperuricemia is a readily modifiable factor, and appropriately preventing it could provide significant benefits in ESRD patients.

Asymptomatic hyperuricemia and coronary artery disease in elderly patients without comorbidities

Because many subjects with hyperuricemia have comorbidities, it can be difficult to differentiate the role of hyperuricemia from that of other comorbidities of coronary artery disease (CAD). Subjects aged ≥ 65 years were enrolled in the study and were available at enrollment and at 5-year follow-up. Subjects were excluded if they were overweight or obese, hypertensive, diabetic, hyperlipidemic, had a pre-existing cardiovascular disease, a history of gout or hyperuricemia on medications, or chronic kidney disease as estimated by a glomerular filtration rate (eGFR) < 60 mL/min per 1.73 m². We used Poisson regression to estimate the hazard ratio (HR) for incident CAD events between hyperuricemic (> 7 mg/dL in men and ≥ 6 mg/dL in women) and normouricemic subjects. A total of 2,142 subjects without comorbidities (mean age of 70.7 ± 5.9 years, 1,194 men) were followed for 57.4 ± 8.9 months. Hyperuricemia was associated with an increased cumulative incidence of incident CAD events (15.0% versus 8.8%, P < 0.001). After adjusting for confounding factors, hyperuricemia independently predicted the risk of incident CAD events (HR=1.71, 95% CI 1.26-2.34). In conclusion, asymptomatic hyperuricemia is a valuable biomarker for predicting the development of incident CAD events.

Determination of risk factors affecting the in-hospital prognosis of patients with acute ST segment elevation myocardial infarction after percutaneous coronary intervention

BACKGROUND

To determine the factors affecting the in-hospital prognosis of patients with acute ST segment elevation myocardial infarction (STEMI) after percutaneous coronary intervention (PCI), and to establish its prognostic discriminant model.

METHODS

A total of 701 consecutive STEMI patients undergoing PCI were enrolled in this study. The patients were divided into two groups, good prognosis and poor prognosis, based on whether the patient had adverse outcomes (death or heart function ≥ grade III) at discharge. Demographic and basic clinical characteristics, diagnosis at admission (e.g., ventricular function, complications, or hyperlipidemia), and biomedical indicators (e.g., blood count, basal metabolism and biochemical composition, blood lipid and glucose levels, myocardial biomarkers, and coagulation) were collected and analyzed.

RESULTS

We determined 22 factors as risk factors for the in-hospital prognosis of STEMI patients after PCI: age, cardiac function during hospitalization, complications, history of diabetes mellitus, et al., among which the history of diabetes, uric acid, urea nitrogen, and activated partial thromboplastin time (APTT) were independent risk factors.

CONCLUSION

We identified four independent risk factors for the in-hospital prognosis of STEMI patients after PCI and generated a prognostic model to predict the adverse outcomes of these patients.

Prevalence of hyperuricemia and its related risk factors among preschool children from China

To estimate the prevalence of hyperuricemia and its major risk factors among Chinese preschool children. A cross-sectional survey was carried out in six central urban districts of Tianjin from March to June 2015. A cluster sampling was employed to obtain a random sample of preschool children. A total of 4073 children aged from 3 to 6 years participated in this survey. Logistic regression was used to obtain odds ratios and 95% confidence intervals. The overall mean serum uric acid concentrations was 243.0 ± 53.2 μmol/L, corresponding to a mean concentrations of 247.3 ± 53.7 μmol/L among boys and 238.3 ± 52.4 μmol/L among girls. The overall prevalence of serum uric acid ≥ 310 μmol/L among children was 10.1%. Boys, obesity, diastolic blood pressure, and serum triglyceride concentrations were associated with the increased risk of hyperuricemia in univariable models, although the statistically significant association between diastolic blood pressure, serum triglyceride concentrations and hyperuricemia disappeared in multivariable models. The prevalence of hyperuricemia among children aged from 3 to 6 years was relatively high. Several metabolic syndrome components were associated with the risk of hyperuricemia.

Relationship between plasma xanthine oxidoreductase activity and left ventricular ejection fraction and hypertrophy among cardiac patients

Background and purpose

Xanthine oxidoreductase (XOR), which catalyzes purine catabolism, has two interconvertible forms, xanthine dehydrogenase and xanthine oxidase, the latter of which produces superoxide during uric acid (UA) synthesis. An association between plasma XOR activity and cardiovascular and renal outcomes has been previously suggested. We investigated the potential association between cardiac parameters and plasma XOR activity among cardiology patients.

Methods and results

Plasma XOR activity was measured by [¹³C₂,¹⁵N₂]xanthine coupled with liquid chromatography/triplequadrupole mass spectrometry. Among 270 patients who were not taking UA-lowering drugs, XOR activity was associated with body mass index (BMI), alanine aminotransferase (ALT), HbA1c and renal function. Although XOR activity was not associated with serum UA overall, patients with chronic kidney disease (CKD), those with higher XOR activity had higher serum UA among patients without CKD. Compared with patients with the lowest XOR activity quartile, those with higher three XOR activity quartiles more frequently had left ventricular hypertrophy. In addition, plasma XOR activity showed a U-shaped association with low left ventricular ejection fraction (LVEF) and increased plasma B-type natriuretic peptide (BNP) levels, and these associations were independent of age, gender, BMI, ALT, HbA1C, serum UA, and CKD stages.

Conclusions

Among cardiac patients, left ventricular hypertrophy, low LVEF, and increased BNP were significantly associated with plasma XOR activity independent of various confounding factors. Whether pharmaceutical modification of plasma XOR activity might inhibit cardiac remodeling and improve cardiovascular outcome should be investigated in future studies.

Recent advances on uric acid transporters

Uric acid is the product of purine metabolism and its increased levels result in hyperuricemia. A number of epidemiological reports link hyperuricemia with multiple disorders, such as kidney diseases, cardiovascular diseases and diabetes. Recent studies also showed that expression and functional changes of urate transporters are associated with hyperuricemia. Uric acid transporters are divided into two categories: urate reabsorption transporters, including urate anion transporter 1 (URAT1), organic anion transporter 4 (OAT4) and glucose transporter 9 (GLUT9), and urate excretion transporetrs, including OAT1, OAT3, urate transporter (UAT), multidrug resistance protein 4 (MRP4/ABCC4), ABCG-2 and sodium-dependent phosphate transport protein. In the kidney, uric acid transporters decrease the reabsorption of urate and increase its secretion. These transporters’ dysfunction would lead to hyperuricemia. As the function of urate transporters is important to control the level of serum uric acid, studies on the functional role of uric acid transporter may provide a new strategy to treat hyperuricemia associated diseases, such as gout, chronic kidney disease, hyperlipidemia, hypertension, coronary heart disease, diabetes and other disorders. This review article summarizes the physiology of urate reabsorption and excretion transporters and highlights the recent advances on their roles in hyperuricemia and various diseases.

Hyperuricemia and clustering of cardiovascular risk factors in the Chinese adult population

Hyperuricemia is common in China and the relevance of hyperuricemia and cardiovascular disease (CVD) risk has been highlighted, but to date there has been rarely nation-wide study in China. Here, we aim to estimate the current prevalence of hyperuricemia and evaluate the associations between hyperuricemia and cardiovascular risk factors (CRFs) clustering in a large sample of China adults including a plurality of ethnic minorities. Generally, a nationally representative sample of 22983 adults aged ≥18 years was recruited from 2007 to 2011. Questionnaire data and information on anthropometric characteristics, and laboratory measurements were collected. We define hyperuricemia as SUA ≥416 mmol/L for men and SUA ≥357 mmol/L for women. We found that the prevalence of hyperuricemia was 13.0% (18.5% in men and 8.0% in women). To our estimation, hyperuricemic subjects had higher prevalence rates of CRFs clustering than non-hyperuricemic subjects. Furthermore, there was a dose-response association between the number of CVD risk factors clustering and hyperuricemia. Our study revealed a high prevalence of hyperuricemia and CVD risk factors clustering among Chinese adults, and hyperuricemia was significantly associated with coexistence of more CVD risk factors. Therefore, guidance and effective lifestyle intervention are required to prevent hyperuricemia and CVD risk factors in China.

Serum uric acid levels and multiple health outcomes: umbrella review of evidence from observational studies, randomised controlled trials, and Mendelian randomisation studies

Objective To map the diverse health outcomes associated with serum uric acid (SUA) levels.Design Umbrella review.Data sources Medline, Embase, Cochrane Database of Systematic Reviews, and screening of citations and references.Eligibility criteria Systematic reviews and meta-analyses of observational studies that examined associations between SUA level and health outcomes, meta-analyses of randomised controlled trials that investigated health outcomes related to SUA lowering treatment, and Mendelian randomisation studies that explored the causal associations of SUA level with health outcomes.Results 57 articles reporting 15 systematic reviews and144 meta-analyses of observational studies (76 unique outcomes), 8 articles reporting 31 meta-analyses of randomised controlled trials (20 unique outcomes), and 36 articles reporting 107 Mendelian randomisation studies (56 unique outcomes) met the eligibility criteria. Across all three study types, 136 unique health outcomes were reported. 16 unique outcomes in meta-analyses of observational studies had P<10-6, 8 unique outcomes in meta-analyses of randomised controlled trials had P<0.001, and 4 unique outcomes in Mendelian randomisation studies had P<0.01. Large between study heterogeneity was common (80% and 45% in meta-analyses of observational studies and of randomised controlled trials, respectively). 42 (55%) meta-analyses of observational studies and 7 (35%) meta-analyses of randomised controlled trials showed evidence of small study effects or excess significance bias. No associations from meta-analyses of observational studies were classified as convincing; five associations were classified as highly suggestive (increased risk of heart failure, hypertension, impaired fasting glucose or diabetes, chronic kidney disease, coronary heart disease mortality with high SUA levels). Only one outcome from randomised controlled trials (decreased risk of nephrolithiasis recurrence with SUA lowering treatment) had P<0.001, a 95% prediction interval excluding the null, and no large heterogeneity or bias. Only one outcome from Mendelian randomisation studies (increased risk of gout with high SUA levels) presented convincing evidence. Hypertension and chronic kidney disease showed concordant evidence in meta-analyses of observational studies, and in some (but not all) meta-analyses of randomised controlled trials with respective intermediate or surrogate outcomes, but they were not statistically significant in Mendelian randomisation studies.Conclusion Despite a few hundred systematic reviews, meta-analyses, and Mendelian randomisation studies exploring 136 unique health outcomes, convincing evidence of a clear role of SUA level only exists for gout and nephrolithiasis.

Uric acid priming in human monocytes is driven by the AKT-PRAS40 autophagy pathway

Metabolic triggers are important inducers of the inflammatory processes in gout. Whereas the high serum urate levels observed in patients with gout predispose them to the formation of monosodium urate (MSU) crystals, soluble urate also primes for inflammatory signals in cells responding to gout-related stimuli, but also in other common metabolic diseases. In this study, we investigated the mechanisms through which uric acid selectively lowers human blood monocyte production of the natural inhibitor IL-1 receptor antagonist (IL-1Ra) and shifts production toward the highly inflammatory IL-1β. Monocytes from healthy volunteers were first primed with uric acid for 24 h and then subjected to stimulation with lipopolysaccharide (LPS) in the presence or absence of MSU. Transcriptomic analysis revealed broad inflammatory pathways associated with uric acid priming, with NF-κB and mammalian target of rapamycin (mTOR) signaling strongly increased. Functional validation did not identify NF-κB or AMP-activated protein kinase phosphorylation, but uric acid priming induced phosphorylation of AKT and proline-rich AKT substrate 40 kDa (PRAS 40), which in turn activated mTOR. Subsequently, Western blot for the autophagic structure LC3-I and LC3-II (microtubule-associated protein 1A/1B-light chain 3) fractions, as well as fluorescence microscopy of LC3-GFP-overexpressing HeLa cells, revealed lower autophagic activity in cells exposed to uric acid compared with control conditions. Interestingly, reactive oxygen species production was diminished by uric acid priming. Thus, the Akt-PRAS40 pathway is activated by uric acid, which inhibits autophagy and recapitulates the uric acid-induced proinflammatory cytokine phenotype.

Sodium-glucose co-transporter 2 inhibitors for type 2 diabetes mellitus: An overview for the primary care physician

AIMS

Sodium-glucose co-transporter type 2 (SGLT2) inhibitors are a new class of anti-hyperglycaemic agents in type 2 diabetes mellitus (T2DM). This review examines their mechanism of action and provides an overview of safety and efficacy from the main studies of SGLT2 inhibitors marketed in the United States and Europe, namely, canagliflozin, dapagliflozin and empagliflozin.

METHODS

We searched the PubMed database to identify relevant publications on the mechanism of action of SGLT2 inhibitors and clinical trial reports.

RESULTS

Clinical trials in patients with T2DM have shown significant improvements in glycaemic control vs placebo with canagliflozin, dapagliflozin and empagliflozin: patients were more likely to reach target glycated haemoglobin levels compared with patients receiving placebo. All SGLT2 inhibitors also led to modest reductions in body weight and blood pressure vs placebo. Generally, all agents were well tolerated, with the most common adverse events with this class being genital mycotic infections and urinary tract infections. Hypoglycaemia was reported at rates similar to those seen with placebo, except when SGLT2 inhibitors were given in combination with insulin or an insulin secretagogue. Long-term outcome data are available only for empagliflozin: in the EMPA-REG OUTCOME study, empagliflozin demonstrated reduced risk of the composite end-point of 3-point major adverse cardiovascular events (cardiovascular death, non-fatal myocardial infarction or non-fatal stroke), primarily because of a significant reduction in cardiovascular mortality.

CONCLUSIONS

SGLT2 inhibitors are an exciting addition to the list of available agents for T2DM, and may be suitable for various types of patients who need additional glycaemic control.

Hyperuricemia after orthotopic liver transplantation: divergent associations with progression of renal disease, incident end-stage renal disease, and mortality

Background

Although hyperuricemia is common after orthotopic liver transplantation (OLT), its relationship to mortality, progressive kidney disease, or the development of end stage renal disease (ESRD) is not well-described.

Methods

Data from 304 patients undergoing OLT between 1996 and 2010 were used to assess the association of mean serum uric acid (UA) level in the 3-months post-OLT with mortality, doubling of creatinine, and ESRD incidence. Post-OLT survival to event outcomes according to UA level and eGFR was assessed using the Kaplan Meier method and multivariate Cox proportional hazards models.

Results

Mean UA level among the 204 patients with an eGFR level ≥60 ml/min/1.73 m² was 6.4 mg/dl compared to 7.9 mg/dl among the 100 patients with eGFR <60 (p < 0.0001). During a median of 4.6 years of follow-up, mortality rate, doubling of creatinine, and ESRD incidence were 48.9, 278.2, and 20.7 per 1000 person-years, respectively. In the first 5 years of follow-up, elevated UA was associated with mortality (Hazard Ratio, HR = 1.7; p = 0.045). However, among those with eGFR ≥ 60, UA level did not predict mortality (HR = 1.0; p = 0.95), and among those with eGFR < 60, elevated UA was a strong predictor of mortality (HR = 3.7[1.1, 12.0]; p = 0.03). UA was not associated with ESRD, but was associated with doubling of creatinine among diabetics (HR = 2.2[1.1, 4.3]; p = 0.025).

Conclusion

In this post-OLT cohort, hyperuricemia independently predicted mortality, particularly among patients with eGFR < 60, and predicted doubling of creatinine among diabetics.

Electronic supplementary material

The online version of this article (doi:10.1186/s12882-017-0518-5) contains supplementary material, which is available to authorized users.

Allopurinol and the risk of ventricular arrhythmias in the elderly: a study using US Medicare data

BACKGROUND

There are no published human studies investigating whether the use of allopurinol, the most commonly used medication for the treatment of hyperuricemia in gout, the most common type of inflammatory arthritis in adults, has any beneficial effects on ventricular electrophysiology. The objective of our study was to assess whether allopurinol use is associated with a reduction in the risk of ventricular arrhythmias (VA).

METHODS

We used the 5% random sample of Medicare beneficiaries from 2006-2012 to examine new allopurinol use and the risk of incident VA. Multivariable Cox regression analyses were adjusted for demographics (age, race, sex), comorbidity, cardiac medications, and conditions associated with VA. We calculated hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Of the 28,755 episodes of new allopurinol use, 2538 were associated with incident VA (8.8%). Among patients with incident VA, 54% were male, 78% were White, 75% had gout as the underlying diagnosis, and the mean Charlson-Romano comorbidity score was 4.8. The crude incidence of VA per 1,000,000 person-days declined as the duration of allopurinol use increased: 1-180 days, 151; 181 days to 2 years, 105; and > 2 years, 85. In multivariable-adjusted analyses, compared to non-use, allopurinol use was associated with lower HR of VA of 0.82 (95% CI, 0.76-0.90). Compared to allopurinol non-use, longer allopurinol use durations were significantly associated with lower multivariable-adjusted HR for VA: 1-180 days, 0.96 (95% CI, 0.85-1.08); 181 days to 2 years, 0.76 (95% CI, 0.68-0.85); and > 2 years, 0.72 (95% CI, 0.60-0.87). Multiple sensitivity analyses adjusting for cardiac conditions, anti-arrhythmic drugs and alternate definitions confirmed our findings with minimal/no attenuation of estimates.

CONCLUSION

Allopurinol use and use duration of more than 6 months were independently associated with a lower risk of VA. Future studies need to assess the pathophysiology of this potential benefit.

Allopurinol use and the risk of acute cardiovascular events in patients with gout and diabetes

Background

Few studies, if any, have examined cardiovascular outcomes in patients with diabetes and gout. Both diabetes and gout are risk factors for cardiovascular disease. The objective of this study was to examine the effect of allopurinol on the risk of incident acute cardiovascular events in patients with gout and diabetes.

Methods

We used the 2007–2010 Multi-Payer Claims Database (MPCD) that linked health plan data from national commercial and governmental insurances, representing beneficiaries with United Healthcare, Medicare, or Medicaid coverage. In patients with gout and diabetes, we assessed the current allopurinol use, defined as a new filled prescription for allopurinol, as the main predictor of interest. Our outcome of interest was the occurrence of the first Incident hospitalized myocardial infarction (MI) or stroke (composite acute cardiovascular event), after which observations were censored. We employed multivariable-adjusted Cox proportional hazards models that simultaneously adjusted for patient demographics, cardiovascular risk factors and other medical comorbidities. We calculated hazard ratios [HR] (95% confidence intervals [CI]) for incident composite (MI or stroke) acute cardiovascular events. We performed sensitivity analyses that additionally adjusted for the presence of immune diseases and colchicine use, as potential confounders.

Results

There were 2,053,185 person days (5621.3 person years) of current allopurinol use and 1,671,583 person days (4576.5 person years) of prior allopurinol use. There were 158 incident MIs or strokes in current and 151 in prior allopurinol users, respectively. Compared to previous allopurinol users, current allopurinol users had significantly lower adjusted hazard of incident acute cardiovascular events (incident stroke or MI), with an HR of 0.67 (95% CI, 0.53, 0.84). Sensitivity analyses, additionally adjusted for immune diseases or colchicine use, confirmed this association.

Conclusions

Current allopurinol use protected against the occurrence of acute cardiovascular events in patients with gout and diabetes. The underlying mechanisms for this potential cardio-protective effect of allopurinol need further exploration.

Electronic supplementary material

The online version of this article (doi:10.1186/s12872-017-0513-6) contains supplementary material, which is available to authorized users.

Synergistic Degradation of a Hyperuricemia-Causing Metabolite Using One-Pot Enzyme-Nanozyme Cascade Reactions

Multi-enzyme cascade reactions are frequently found in living organisms, in particular when an intermediate should be eliminated. Recently, enzyme-mimic nanomaterials (nanozymes) received much attention for various applications, because they are usually more stable and cost-effective than enzymes. However, enzyme-nanozyme cascade reations have not been yet extensively exploited. Therefore, in this study, we investigated one-pot enzyme-nanozyme cascade reactions using urate oxidase (UOX) and catalase-mimic gold nanoparticle nanozyme (AuNP) with the ultimate goal of treatment of hyperuricemia. UOX degrades hyperuricemia-causing uric acid, but also generates hydrogen peroxide raising several health concerns. We successfully demonstrated that one-pot UOX-AuNP cascade systems degrade uric acid more than five times faster than UOX alone, by eliminating potentially cytotoxic hydrogen peroxide, similar to enzyme-enzyme reactions.

Hiperuricemia assintomática - tratar ou não tratar? - Uma revisão baseada na evidência

Introdução: A avaliação dos níveis séricos de ácido úrico é realizada com frequência nos Cuidados de Saúde Primários, porém sem evidência científica que a justifique. A abordagem terapêutica subsequente constitui frequentemente um desafio clínico, particularmente no caso da hiperuricemia assintomática (HA). O objetivo desta revisão foi rever a evidência sobre a pertinência do tratamento da HA. Métodos: Pesquisa de normas de orientação clínica (NOC), revisões sistemáticas (RS), meta-análises (MA) e estudos originais (EO) no Medline e outros sítios de Medicina Baseada na Evidência, publicados desde abril de 2012 até abril de 2016, em inglês, espanhol e português. Termos MeSH: “hyperuricemia” e ”asymptomatic conditions”. Resultados: Cinco estudos cumpriam os critérios de inclusão: uma MA, três RS e um EO. A MA e o EO recomendam o tratamento da HA, para a prevenção da disfunção renal e para prevenção de eventos cardiovasculares (CV), respetivamente. Duas RS não recomendam o tratamento da HA e uma recomenda uma decisão individualizada para valores de uricemia acima de 9mg/dL, particularmente para a prevenção da gota. Conclusões: A evidência científica disponível é escassa, com limitações, e controversa no que diz respeito à instituição de tratamento farmacológico. O significado clínico da HA e sua relação causal com ocorrência de crises agudas de gota, disfunção renal e doença cardiovascular ainda são incertos. Não existe evidência científica que justifique o tratamento farmacológico da HA em doentes assintomáticos (SOR B). São, por isso, necessários mais estudos, metodologicamente robustos e orientados para o paciente.