Prognostic significance of serum creatinine and uric acid in older Chinese patients with isolated systolic hypertension

Association of serum uric acid with anemia in U.S. adults: a cross-sectional study using secondary data

BACKGROUND

High serum uric acid (SUA) is a risk factor of cardiovascular disease (CVD). Abnormal SUA have been correlated with a significant increase in mortality. Anemia is an independent predictor of mortality and CVD. To date, no study has investigated the relationship between SUA and anemia. Here, we explored the correlation between SUA and anemia in the American population.

METHODS

The cross-sectional study involved 9205 US adults from NHANES (2011-2014). The relationship between SUA and anemia was explored using multivariate linear regression models. Two-piecewise linear regression model, generalized additive models (GAM) and smooth curve fitting were performed to explore the non-linear relationships between SUA and anemia.

RESULTS

We found a U-shaped non-linear relationship between SUA and anemia. The inflection point of the SUA concentration curve was 6.2 mg/dL. The ORs (95% CIs) for anemia on the left and right of the inflection point were 0.86 (0.78-0.95) and 1.33 (1.16-1.52), respectively. The 95% CI of inflection point was 5.9-6.5 mg/dL. The findings showed that both genders presented a U-shaped correlation. Safe ranges of SUA in men and women were 6-6.5 and 4.3-4.6 mg/dL, respectively.

CONCLUSIONS

Both high and low SUA levels were correlated with increased risk of anemia, and a U-shaped relationship was observed between SUA and anemia.

Incident hyperuricemia in relation to antihypertensive therapy with the irbesartan/hydrochlorothiazide combination

OBJECTIVE

We investigated serum uric acid changes and incident hyperuricemia in relation to the achieved blood pressure (BP) after 12 weeks of antihypertensive therapy with the irbesartan/hydrochlorothiazide combination.

METHODS

The study participants were 449 patients who completed the study. Analysis of covariance and multiple logistic regression analyses were performed to calculate the least square mean changes (± standard error) from baseline in serum uric acid and odds ratios (ORs) for incident hyperuricemia according to the achieved levels of BP.

RESULTS

Adjusted analyses showed that serum uric acid changes differed according to the achieved SBP/DBP (P = 0.002), with a smaller mean (± standard error) increase in the range of 130-139/<90 mm Hg (n = 132, 19.8 ± 5.7 µmol/L) than that of ≥140/90 (n = 129, 32.4 ± 7.3 µmol/L) or <130/90 mm Hg (n = 188, 39.5 ± 5.1 µmol/L). Adjusted analyses showed similar results for the incident hyperuricemia (n = 95, 24.0%) in those patients with normal serum uric acid at baseline (n = 396). The risk of incident hyperuricemia was lower (OR, 0.45; 95% confidence interval 0.25-0.83; P = 0.04) in patients with an achieved SBP/DBP of 130-139/<90 mm Hg (n = 117, incidence rate, 17.1%) than those with an achieved SBP/DBP of ≥140/90 (n = 118, 31.4%) or <130/90 mm Hg (n = 161, 23.6%).

CONCLUSIONS

Thiazide-induced changes in serum uric acid or incident hyperuricemia were associated with the achieved SBP/DBP, being lower at the level of 130-139/<90 mm Hg.

Serum Uric Acid Is a Weak Independent Predictor of Overall Survival in Older Adults

Hyperuricemia accompanies many pathologies that contribute to overall death rate. The population-based multifaceted study of older adults in Poland made it possible to assess the effect of serum uric acid (SUA) on overall mortality. The PolSenior study performed between 2007–2011 included 3926 participants aged 65 years or above (mean age 79 ± 9 years) not treated with xanthin oxidase inhibitors (XOI) who were stratified by sex and SUA concentration into six subgroups increasing by 1 mg/dL. In 2019, survival data were retrieved from the population register. The crude risk of death was significantly higher in men and women with SUA ≥ 7 mg/dL. After adjustment to statistically significant factors, SUA remained a risk factor of death in men with SUA ≥ 8 mg/dL only, potentially due to the limited number of women with high SUA levels. Furthermore, age, heart failure, diabetes, and activities of daily living ≤ 4 pts were identified as factors increasing mortality risk regardless of sex. The risk of death increased also with smoking, past stroke, COPD/asthma, and hs-CRP > 3 mg/dL for men; and eGFR < 45 mL/min/1.73 m², mini nutritional assessment ≤ 7 pts, and loop diuretics use for women. Mild hyperuricemia is a significant health status marker and an independent risk factor for overall mortality in older Caucasians not receiving XOI. Increased mortality is mostly limited to subjects with SUA levels ≥ 8 mg/dL.

Association of serum uric acid with mortality and cardiovascular outcomes in patients with hypertension: a meta-analysis

Studies on the association of uric acid with mortality and cardiovascular outcomes in patients with hypertension have produced contradictory results. The objective of this meta-analysis was to evaluate the prognostic utility of uric acid in hypertensive patients. We comprehensively searched PubMed and Embase databases (until July 31, 2020) to identify eligible studies that reported the association of uric acid with mortality and cardiovascular outcomes in hypertensive patients. Outcome measures included cardiovascular or all-cause mortality, coronary artery disease (CAD), stroke, and major adverse cardiovascular events (MACEs). Eleven eligible studies of 49,800 hypertensive patients were identified. For patients with the highest than those with reference lower group of uric acid level, the pooled hazard ratio (HR) was 1.51 (95% confidence interval [CI] 1.12-2.02) for all-cause mortality, 1.68 (95% CI 1.28-2.20) for cardiovascular mortality, 1.31 (95% CI 1.10-1.55) for CAD, and 1.48 (95% CI 1.28-1.70) for MACEs. However, there was no significant association between elevated uric acid level and incident stroke in hypertensive patients. This meta-analysis indicates that elevated uric acid level is significantly associated with an increased risk of cardiovascular or all-cause mortality, CAD and MACEs in hypertensive patients. Hypertensive patients with highest uric acid level exhibited a tendency for reduced risk of stroke, but the difference is not significant.

Prevalence of Hyperuricemia and the Use of Allopurinol in Older Poles-Results from a Population-Based PolSenior Study

BACKGROUND

Our study analyzes the frequency and risk factors of hyperuricemia and the use of allopurinol in a representative cohort of the older Polish adult population.

METHODS

The analysis was a part of a cross-sectional PolSenior study on aging in Poland. The complete medication data were available in 4873 out of 4979 community dwelling respondents aged 65 and over. Serum uric acid concentrations were evaluated in 4028 participants (80.9% of the cohort).

RESULTS

Hyperuricemia was observed in 28.2% of women and 24.7% of men. Ten risk factors of hyperuricemia were selected based on multivariable LASSO logistic regression analysis. Nine factors showed significant odds ratios: eGFR < 60 mL/min/1.73 m2 (OR = 4.10), hypertriglyceridemia (OR = 1.88), obesity (OR = 1.75), heart failure (1.70), CRP > 3.0 mg/dL (OR = 1.64), coronary artery disease (OR = 1.30), use of loop-diuretics (OR = 4.20), hydrochlorothiazide (OR = 2.96), and thiazide-like diuretics (OR = 2.81). Allopurinol was used by 2.8% of men and 1.8% of women. The therapy was considered effective in 46.7% of men and 53.3% of women.

CONCLUSIONS

Hyperuricemia was present in 23.1% (95% CI: 21.8-24.4) of the older Polish population. The frequency of hyperuricemia increases with age, reaching 30.5% in men and 33.7% in women aged 90 years or more. Chronic kidney disease, obesity, heart failure, hypertriglyceridemia, and the use of diuretics were the strongest risk factors for hyperuricemia in older adults. The treatment with allopurinol was ineffective in more than half of participants.

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

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

The differential role of uric acid - The purpose or cause of cardiovascular diseases?

For 40 years many studies have been conducted to verify the connection between serum uric acid concentration and cardiovascular diseases, such as myocardial infarction. Unfortunately, it remains unclear which form of uric acid - prooxidant or antioxidant - could be a predictive marker of cardiovascular disease, especially in patients after myocardial infarction. It is well-known that uric acid is an organic compound and the water-soluble final product of purine catabolism, which is catalysed by xanthine oxidoreductase and excreted by kidneys. An increased concentration of UA in human plasma leads to diseases like tumours, renal disorders, atherosclerosis, hypertension, diabetes, metabolic syndrome, polycythaemia vera, haemolytic anaemias, ischemia, oxidative stress, and rare genetic disorders connected with UA degradation. Epidemiological studies have shown that UA might be a marker of oxidative stress, progression of inflammation, or renal disease. A fortiori, it is possible that could also be a predictor for short/long-term survival of patients with CVD. Evidence provided by multiple studies is controversial and mutually exclusive. Among 71 studies the most of them found an independent association between SUA and CVD risk. Some of those studies confirm that CVD risk is higher in women who had elevated SUA levels. On the other hand, many studies reached the opposite conclusion and did not find any relationship between SUA and CVD mortality and morbidity.

Platelet mitochondrial DNA methylation predicts future cardiovascular outcome in adults with overweight and obesity

BACKGROUND

The association between obesity and cardiovascular disease (CVD) is proven, but why some adults with obesity develop CVD while others remain disease-free is poorly understood. Here, we investigated whether mitochondrial DNA (mtDNA) methylation in platelets is altered prior to CVD development in a population of adults with overweight and obesity.

METHODS

We devised a nested case-control study of 200 adults with overweight or obesity who were CVD-free at baseline, of whom 84 developed CVD within 5 years, while 116 remained CVD-free. Platelet mtDNA was isolated from plasma samples at baseline, and mtDNA methylation was quantified in mitochondrially encoded cytochrome-C-oxidase I (MT-CO1; nt6797 and nt6807), II (MT-CO2; nt8113 and nt8117), and III (MT-CO3; nt9444 and nt9449); tRNA leucine 1 (MT-TL1; nt3247 and nt3254); D-loop (nt16383); tRNA phenylalanine (MT-TF; nt624); and light-strand-origin-of-replication (MT-OLR; nt5737, nt5740, and nt5743) by bisulfite-pyrosequencing. Logistic regression was used to estimate the contribution of mtDNA methylation to future CVD risk. ROC curve analysis was used to identify the optimal mtDNA methylation threshold for future CVD risk prediction. A model was generated incorporating methylation at three loci (score 0, 1, or 2 according to 0, 1, or 2-3 hypermethylated loci, respectively), adjusted for potential confounders, such as diastolic and systolic blood pressure, fasting blood glucose, and cholesterol ratio. mtDNA methylation at MT-CO1 nt6807 (OR = 1.08, 95% CI 1.02-1.16; P = 0.014), MT-CO3 nt9444 (OR = 1.22, 95% CI 1.02-1.46, P = 0.042), and MT-TL1 nt3254 (OR = 1.30, 95% CI 1.05-1.61, P = 0.008) was higher at baseline in those who developed CVD by follow-up, compared with those who remained CVD-free. Combined use of the three loci significantly enhanced risk prediction, with hazard ratios of 1.38 (95% CI 0.68-2.78) and 2.68 (95% CI 1.41-5.08) for individuals with score 1 or 2, respectively (P = 0.003). Methylation at these sites was independent of conventional CVD risk factors, including inflammation markers, fasting blood glucose concentration, and blood pressure.

CONCLUSIONS

Methylations of MT-CO1, MT-CO3, and MT-TL1 are, together, strong predictors of future CVD incidence. Since methylation of these mtDNA domains was independent of conventional CVD risk factors, these markers may represent a novel intrinsic predictor of CVD risk in adults with overweight and obesity.

Uric Acid and Arterial Stiffness

Hyperuricemia is usually associated with hypertension, diabetes mellitus, metabolic syndrome and chronic kidney disease. Accumulating data from epidemiological studies indicate an association of increased uric acid (UA) with cardiovascular diseases. Possible pathogenic mechanisms include enhancement of oxidative stress and systemic inflammation caused by hyperuricemia. Arterial stiffness may be one of the possible pathways between hyperuricemia and cardiovascular disease, but a clear relationship between increased UA and vascular alterations has not been confirmed. The review summarizes the epidemiological studies investigating the relationship between UA and arterial stiffness and highlights the results of interventional studies evaluating arterial stiffness parameters in patients treated with UA-lowering drugs.

J-shaped association between serum uric acid and acute coronary syndrome in patients with essential hypertension

BACKGROUND

The prognostic value of serum uric acid (SUA) for incident acute coronary syndrome (ACS) in hypertensive subjects is uncertain. Therefore, the present study examined the association between SUA and incident ACS in a large cohort of Chinese hypertensive adults.

METHODS

This was a retrospective cohort study, which enrolled 5473 Chinese community-dwelling hypertensive patients from 1 January 2012 to 31 December 2012. Study outcomes were ACS events, and patients were followed until 31 December 2016. Cox regression analyses were conducted to determine adjusted HRs and 95% CIs for baseline SUA tertiles (low, middle and high group) and for men and women separately.

RESULTS

A total of 5473 participants were included in the analysis (median follow-up was 4.5 years). Participants were divided into tertiles based on SUA levels. During follow-up, 9 (0.49%), 14 (0.77%) and 25 (1.37%) patients developed ACS in the lowest, middle and highest tertiles, respectively. When compared with the lowest tertile of SUA, the highest tertile of SUA was associated with ACS risk in all subjects and in men and women separately (HR: 2.62, 95% CI 1.14 to 7.01, p=0.0233; 2.15, 95% CI 1.08 to 6.04, p=0.021, and 3.49, 95% CI 1.25 to 7.74, p=0.017, respectively).

CONCLUSIONS

Higher SUA levels were independently associated with an elevated risk of ACS incidence. The relationship between SUA levels and ACS in hypertensive patients was J-shaped.

Asymptomatic hyperuricemia and incident stroke in elderly Chinese patients without comorbidities

BACKGROUND/OBJECTIVES

Hyperuricemia is usually associated with other comorbidities; so it is difficult to distinguish the effects of hyperuricemia from other coexisting comorbidities in patients who suffer a stroke.

SUBJECT/METHODS

Data for this study were collected from the patients of Kangjian Community Health Center of Shanghai. Selected participants ≥65 years of age were available at enrollment (2009-2013). Subjects were excluded if they had hypertension, diabetes mellitus, pre-existing cardiovascular disease, or hyperlipidemia. Further, patients who were overweight or obese, had gout or drug-treated hyperuricemia, or had chronic kidney disease were also excluded. Cox regression was used in order to assess the hazard ratio (HR) for the incidence of stroke events between hyperuricemic and normouricemic patients.

RESULTS

A total of 3243 subjects without comorbidities (70.8 ± 6.0 years) were followed for 35.5 ± 3.0 months. Hyperuricemia conferred increased cumulative incident stroke events (6.9 versus 3.1%, odds ratio [OR] = 2.27, 95% confidence index [CI] 1.52-3.37, p < 0.001). Male and female hyperuricemic subjects also showed a significantly higher incident stroke incidence than normouricemic subjects (6.1 versus 2.7%, OR = 2.34, 95% CI 1.31-4.18, p = 0.003 and 7.6 versus 3.7%, OR = 2.16, 95% CI 1.25-3.72, p = 0.005, respectively). Cox regression showed that hyperuricemia independently predicted incident stroke risk (HR = 2.32, 95%CI 1.56-3.45).

CONCLUSION

Asymptomatic hyperuricemia carried a significant risk of stroke events in Chinese elderly without comorbidities.

Dietary Sodium Intake and Serum Uric Acid: A Mini-Review

The aim of the present review is to summarize recent studies on the relationship between dietary sodium intake and serum uric acid concentration. In short-term dietary sodium intervention studies, including a recent further analysis of a previously published trial, high dietary sodium intake (200 mmol/day), compared with a low sodium diet (20-60 mmol/day), resulted in a significant reduction in serum uric acid, being approximately 20-60 μmol/L. This finding, though consistent across short-term studies, is in contradiction to the long-term observational evidence on the relationship between dietary sodium intake and serum uric acid. Indeed, in a population-based prospective study, high dietary sodium intake was associated with a higher serum uric acid concentration. If serum uric acid would be followed up, several currently ongoing long-term randomized dietary sodium intervention studies may shed some light on how dietary sodium intake interacts with serum uric acid in the development of hypertension.

Cardiovascular Disease Consequences of CKD

Chronic kidney disease, defined as reduced glomerular filtration rate (estimated using serum creatinine- and/or serum cystatin C-based equations) or excess urinary protein excretion, affects approximately 13% of adult Americans and is linked to a variety of clinical complications. Although persons with end-stage renal disease requiring chronic dialysis therapy experience a substantially high cardiovascular burden, whether mild-to-moderate chronic kidney disease is an independent risk factor for fatal and nonfatal cardiovascular events has been more controversial. This review evaluates the current evidence about the clinical and subclinical cardiovascular consequences associated with chronic kidney disease of varying levels of severity. In addition, it discusses the predictors of adverse cardiovascular outcomes while also focusing on recent insights into the relationships between chronic kidney disease and cardiovascular disease from the Chronic Renal Insufficiency Cohort study, a large current prospective cohort study of adults from across the spectrum of chronic kidney disease.

Hyperuricemia, Cardiovascular Disease, and Hypertension

In recent years, there has been an increase in the prevalence of hyperuricemia, and the latter has attracted attention as an adult lifestyle-associated disease, together with hypertension, diabetes, and dyslipidemia. Although hyperuricemia is known to be an independent risk factor for hypertension, whether it is an independent risk factor for cardiovascular disease remains controversial. Recently, some small-scale interventional studies on antihyperuricemic medications showed that the latter improved angina symptoms and prevented cardiovascular disease. Here, we will mainly explain the cause of hyperuricemia and the associations between hyperuricemia, hypertension, and cardiovascular disease based on the latest published evidence.

Effect of combination tablets containing amlodipine 10 mg and irbesartan 100 mg on blood pressure and cardiovascular risk factors in patients with hypertension

Background

Hypertension is one of the major risk factors for cardiovascular and cerebrovascular disease and mortality. Patients who receive insufficient doses of antihypertensive agents or who are poorly adherent to multidrug treatment regimens often fail to achieve adequate blood pressure (BP) control. The aim of this study was to determine the efficacy of an angiotensin II receptor blocker (ARB) and calcium channel blocker (CCB) combination tablet containing a regular dose of irbesartan (100 mg) and a high dose of amlodipine (10 mg) with regard to lowering BP and other risk factors for cardiovascular disease.

Methods

We retrospectively evaluated data from 68 patients with essential hypertension whose treatment regimen was changed either from combination treatment with an independent ARB and a low-dose or regular-dose CCB or from a combination tablet of ARB and a low-dose or regular-dose CCB to a combination tablet containing amlodipine 10 mg and irbesartan 100 mg, because of incomplete BP control. Previous treatments did not include irbesartan as the ARB.

Results

The combination tablet decreased systolic and diastolic BP. In addition, it significantly decreased serum uric acid, low-density lipoprotein cholesterol, and increased high-density lipoprotein cholesterol levels, independent of the BP-lowering effect. Treatment with the combination tablet did not affect serum triglycerides, plasma glucose, glycated hemoglobin, serum potassium or creatinine levels, or the urinary albumin excretion rate.

Conclusion

The combination tablet containing amlodipine 10 mg and irbesartan 100 mg had a greater BP-lowering effect than an ARB and a low-dose or regular-dose CCB. In addition, the combination tablet had more favorable effects on serum uric acid, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol levels in patients with hypertension.

Development and validation of the Surgical Outcome Risk Tool (SORT)

Background

Existing risk stratification tools have limitations and clinical experience suggests they are not used routinely. The aim of this study was to develop and validate a preoperative risk stratification tool to predict 30-day mortality after non-cardiac surgery in adults by analysis of data from the observational National Confidential Enquiry into Patient Outcome and Death (NCEPOD) Knowing the Risk study.

Methods

The data set was split into derivation and validation cohorts. Logistic regression was used to construct a model in the derivation cohort to create the Surgical Outcome Risk Tool (SORT), which was tested in the validation cohort.

Results

Prospective data for 19 097 cases in 326 hospitals were obtained from the NCEPOD study. Following exclusion of 2309, details of 16 788 patients were analysed (derivation cohort 11 219, validation cohort 5569). A model of 45 risk factors was refined on repeated regression analyses to develop a model comprising six variables: American Society of Anesthesiologists Physical Status (ASA-PS) grade, urgency of surgery (expedited, urgent, immediate), high-risk surgical specialty (gastrointestinal, thoracic, vascular), surgical severity (from minor to complex major), cancer and age 65 years or over. In the validation cohort, the SORT was well calibrated and demonstrated better discrimination than the ASA-PS and Surgical Risk Scale; areas under the receiver operating characteristic (ROC) curve were 0·91 (95 per cent c.i. 0·88 to 0·94), 0·87 (0·84 to 0·91) and 0·88 (0·84 to 0·92) respectively (P < 0·001).

Conclusion

The SORT allows rapid and simple data entry of six preoperative variables, and provides a percentage mortality risk for individuals undergoing surgery.

Comparison of olmesartan combined with a calcium channel blocker or a diuretic in elderly hypertensive patients (COLM Study): safety and tolerability

The cardiovascular effects of combined therapy with the angiotensin receptor blocker (olmesartan) and a dihydropyridine calcium channel blocker (CCB) or a diuretic were compared in high-risk elderly Japanese hypertensive patients by performing a randomized, open label, blinded-endpoint study of morbidity and mortality (the COLM study). Here we report the results obtained with respect to safety and tolerability. High-risk hypertensive patients aged 65–84 years were enrolled and were randomized to receive olmesartan combined with either a CCB (amlodipine or azelnidipine) or a low-dose diuretic for at least 3 years. The primary endpoint was a composite of fatal and non fatal cardiovascular events, whereas adverse events (AEs) and the percentage of patients who discontinued the allocated treatment were evaluated as secondary endpoints. A total of 5141 patients were randomized. Both combination regimens achieved a similar reduction of cardiovascular morbidity and mortality. The incidences of AEs, serious AEs, drug-related serious AEs and discontinuation due to serious AEs were lower in the olmesartan plus CCB group than in the olmesartan plus diuretic group. Serum levels of uric acid and creatinine were significantly higher in the olmesartan plus diuretic group than in the olmesartan plus CCB group. Olmesartan combined with a CCB was significantly superior to olmesartan plus a diuretic with regard to the frequency of AEs and discontinuation of treatment.

The relationship between serum levels of uric acid and prognosis of infection in critically ill patients

BACKGROUND

Serum uric acid level is associated with some chronic diseases and prognosis of severe infection. This study aimed to investigate the relationship between serum uric acid (SUA) and prognosis of infection in critically ill patients.

METHODS

The data from 471 patients with infection admitted from January 2003 to April 2010 were analyzed retrospectively at Huashan Hospital Affiliated to Fudan University, Shanghai, China. The data of SUA, serum creatinine, blood urea nitrogen (BUN) and other relevant examinations within 24 hours after admission were recorded and the levels of SUA in those patients were described, then Student's t test was used to evaluate the relationship between SUA and pre-existing disorders. Different levels of SUA were graded for further analysis. The Chi-square test was used to examine the difference in the prognosis of infection.

RESULTS

The mean initial level of SUA within 24 hours after admission was 0.232±0.131 mmol/L and the median was 0.199 mmol/L. Remarkable variations in the initial levels of SUA were observed in patients with pre-existing hypertension (t=-3.084, P=0.002), diabetes mellitus (t=-2.487, P=0.013), cerebral infarction (t=-3.061, P=0.002), renal insufficiency (t=-4.547, P<0.001), central nervous system infection (t=5.096, P<0.001) and trauma (t=2.875, P=0.004). SUA was linearly correlated with serum creatinine and BUN (F=159.470 and 165.059, respectively, P<0.001). No statistical correlation was found between the initial levels of SUA and prognosis of infection (χ2=60.892, P=0.100).

CONCLUSION

The current study found no direct correlation between the initial levels of SUA after admission and prognosis of infection in critically ill patients.

Osteonecrosis with renal damage in HIV patients undergoing HAART

Rheumatoid arthritis in HIV patients undergoing HAART is associated with increased risk of side effect. Elevation of uric acid (UA) is important in tissue damage, deposition of crystal in joints leads to the development of rheumatoid arthritis in the HAART complaint group. This study was carried out to investigate the relationship of uric acid, RA factor, ANA, ESR, cystatin C, urea and creatinine in the HAART complaint group. Moreover; the ratio of uric acid/cystatin C, uric acid/urea and uric acid/creatinine were also studied. To analyze the progression of HIV, the immunological parameters were correlated with uric acid. Our result showed a statistically high significant increase in uric acid, RA factor, ANA, ESR, cystatin C, urea and creatinine in the HAART complaint group when compared to HAART non-complaint group, early stage and control. The ratio of uric acid/cystatin C, uric acid/urea, uric acid/creatinine were significantly increased in the HAART complaint group. Statistically significant positive correlation was observed between uric acid and cystatin C, urea, creatinine, absolute CD4 and CD8 count. The increased level of uric acid, RA factor, ANA, ESR, cystatin C and increased ratio of uric acid/cystatin C in the HAART complaint group might conclude the mechanism underlying the increased risk for rheumatoid arthritis in the HAART complaint group which may relate to the combined effects of low-grade inflammation and renal dysfunction.

Association of uric acid and carotid artery disease in patients with ischemic stroke

BACKGROUND AND PURPOSE

Some previous studies reported an independent association between uric acid and coronary artery disease, while little is known on the association among uric acid and carotid artery disease (CAD). To address this issue, we investigated the association between CAD and higher uric acid level because of the well-known importance of the carotid artery pathologies for ischemic stroke.

METHODS

Between 2009 and 2012, we conducted a study among 406 consecutive first-ever ischemic stroke patients to assess the relationship between uric acid and carotid artery. A mean intima-media thickness IMT was calculated for the wall of the left and right common carotid arteries (CCA) and IMT of the bifurcation of the carotid arteries. CAD was assessed by neuroimaging techniques in patients with carotid artery stenosis more than 50%. Logistic regression models were used to determine the relation among pathological changes of the carotid artery and higher uric acid level.

RESULTS

In patients with hyperuricemia, the frequency of age (>60 years), hypertriglyceridemia, higher apo B, renal failure were significantly higher than those with normal uric acid level. CAD was more frequent in patients with hyperuricemia than those with normal uric acid level (OR, 1.8, 95% CI, 1.1-3.1; P = 0.01). In patients with higher uric acid level, the mean of the IMT of the CCA and of the bifurcation of the carotid artery were higher than those with normal uric acid level (P = 0.001 for each). Covariance matrix analysis displayed a strong correlation between CAD and age (>60 years) (P < 0.05), sex (P < 0.01), hyperuricemia (P < 0.01), hypertension (P < 0.05), and hypercholesterolemia (P < 0.05). In the models of regression analysis, a strong association was found among patients with CAD and sex, renal failure, hyperuricemia, number of plaques, and size of plaques.

CONCLUSION

Our study demonstrated that higher uric acid level is strongly associated with CAD. Elevated uric acid might be injurious for large cerebral arteries with some probable confounding risk factors. Further prospective large clinical trials will determine whether lowering uric acid level reduces the frequency of CAD and ischemic stroke.

Uric acid and risk of heart failure: a systematic review and meta-analysis

AIMS

We aimed to perform a systematic review and meta-analysis to assess the association between serum uric acid and incident heart failure (HF)/prognosis of HF patients.

METHODS AND RESULTS

A systematic electronic literature search was conducted in Embase (Ovid SP, from 1974 to May 2013), Medline (Ovid SP, from 1946 to May 2013), and the Chinese Biomedical Literature Database (CBM, from 1978 to May 2013) to identify studies reporting on the association between serum uric acid and HF. Either a random effects model or a fixed effects model was used for pooling data. Five studies reporting on incident HF and 28 studies reporting on the adverse outcomes of HF patients were included. The results showed that hyperuricaemia was associated with an increased risk of incident HF [hazard ratio (HR) 1.65, 95% confidence interval (CI) 1.41-1.94], and the risk of all-cause mortality (HR 2.15, 95% CI 1.64-2.83), cardiovascular mortality (HR 1.45, 95% CI 1.18-1.78), and the composite of death or cardiac events (HR 1.39, 95% CI 1.18-1.63) in HF patients. For every 1 mg/dL increase in serum uric acid, the odds of development of HF increased by 19% (HR 1.19, 95% CI 1.17-1.21), and the risk of all-cause mortality and the composite endpoint in HF patients increased by 4% (HR 1.04, 95% CI 1.02-1.06) and 28% (HR 1.28, 95% CI 0.97-1.70), respectively. Subgroup analyses supported the positive association between serum uric acid and HF.

CONCLUSIONS

Elevated serum uric acid is associated with an increased risk of incident HF and adverse outcomes in HF patients.

Independent and conjoint associations of gout and hyperuricaemia with total and cardiovascular mortality

BACKGROUND

Gout and serum uric acid are associated with mortality but their simultaneous contributions have not been fully evaluated in the general population.

PURPOSE

To explore the independent and conjoint relationships of gout and uric acid with mortality in the US population.

METHODS

Mortality risks of gout and serum uric acid were determined for 15 773 participants, aged 20 years or older, in the Third National Health and Nutrition Examination Survey by linking baseline information collected during 1988-1994 with mortality data up to 2006. Multivariable Cox proportional hazards regression determined adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for each exposure and all analyses were conducted in 2011 and 2012.

RESULTS

Compared with subjects without a history of gout, the multivariable HR for subjects with gout were 1.42 (CI 1.12-1.82) for total and 1.58 (CI 1.13-2.19) for cardiovascular mortality. Adjusted HRs per 59.5 µmol/l (1 mg/dl) increase in uric acid were 1.16 (CI 1.10-1.22) for total and cardiovascular mortality and this pattern was consistent across disease categories. In the conjoint analysis, the adjusted HRs for mortality in the highest two uric acid quartiles were 1.64 (CI 1.08-2.51) and 1.77 (CI 1.23-2.55), respectively, for subjects with gout, and were 1.09 (CI 0.87-1.37) and 1.37 (CI (1.11-1.70), respectively, for subjects without gout, compared with those without gout in the lowest quartile. A similar pattern emerged for cardiovascular mortality.

CONCLUSION

Gout and serum uric acid independently associate with total and cardiovascular mortality. These risks increase with rising uric acid concentrations.

Hyperuricemia and hypertension

Over the past century, uric acid has been considered a possible risk factor for hypertension and cardiovascular disease. However, only in the past decade, animal models and clinical trials have supported a more mechanistic link. Results from animal models suggest a 2-phase mechanism for the development of hyperuricemic hypertension in which uric acid induces acute vasoconstriction by activation of renin-angiotensin system, followed by uric acid uptake into vascular smooth muscle cells leading to cellular proliferation and secondary arteriolosclerosis that impairs pressure natriuresis. This acute hypertension remains uric acid dependent and sodium independent, whereas the chronic hypertension becomes uric acid independent and sodium dependent. Small clinical trials, performed in adolescents with newly diagnosed essential hypertension, demonstrate that reduction of serum uric acid can reduce blood pressure. Although more research is clearly necessary, the available data suggest that uric acid is likely causative in some cases of early onset hypertension.

Predictive value of serum uric acid levels for the diagnosis of metabolic syndrome in adolescents

OBJECTIVE

To evaluate the cause-effect relationships between serum levels of uric acid (UA) and metabolic syndrome (MetS) in an adolescent-male cohort that was followed for 2.7 years.

STUDY DESIGN

We enrolled male adolescents aged between 10 and 15 years at the baseline. A total of 613 subjects were divided into quartiles according to their UA levels, from UA-1 (the lowest) to UA-4 (the highest).

RESULTS

After the mean follow-up period of 2.7 ± 0.97 years, 19 (3.1%) subjects developed MetS. Waist circumference (WC), systolic blood pressure, high density lipoprotein cholesterol (HDL-C), and log triglyceride levels were significantly related to baseline UA levels. Compared with the UA-1 group, subjects in the UA-4 group had significantly higher OR for abnormal WC, blood pressure, and HDL-C at the end of follow-up and had a 6.39-fold higher OR (95% CI 1.41-29.08; P < .05) for having MetS. Subjects with UA >7.6 mg/dL had a 4.32 (95% CI 1.57-11.93) higher risk of developing MetS.

CONCLUSIONS

In this longitudinal study, we found that serum UA is correlated with future WC, systolic blood pressure, triglyceride, and HDL-C and is a risk factor for developing MetS. UA might be valuable in predicting adolescent MetS.

Ischemic stroke among the patients with end-stage renal disease who were undergoing maintenance dialysis

PURPOSE

In spite of higher incidence of stroke in end-stage renal disease (ESRD) patients compared to general population, the risk factor for stroke which is specific to ESRD is not fully understood. The ESRD patients who develop stroke may have certain additional risk factors compared to ESRD patients without stroke. We used registered data of Hallym Stroke Registry to elucidate the factors which affect development of ischemic stroke among the dialysis patients.

MATERIALS AND METHODS

We recruited patients with acute ischemic stroke in ESRD patients undergoing maintenance dialysis. Dialysis patients without stroke were selected as control group with age and gender matching. We compared the demographic features, stroke risk factors, and laboratory findings in ESRD patients with or without ischemic stroke.

RESULTS

The total of 25 patients with ESRD developed ischemic stroke. Fifty ESRD patients without stroke were chosen as the control group. The mean age of acute ischemic stroke patients was 59.80±9.94 and male gender was 48%. The most common ischemic stroke subtype was small vessel occlusion (n=12), followed by large artery atherosclerosis (n=7). The patients with stroke had more frequent history of hypertension and higher systolic/diastolic blood pressure at the time of admission than the ESRD patients without stroke. Total cholesterol and LDL-cholesterol levels were significantly lower in the stroke group. In multivariate analysis, LDL-cholesterol was found to be the only risk factor for ischemic stroke.

CONCLUSION

The results of our study reveal that LDL-cholesterol is associated with greater risk for ischemic stroke in the patients on dialysis.

Effects of cilnidipine on serum uric acid level and urinary nitrogen monoxide excretion in patients with hypertension

The effects of cilnidipine on the serum uric acid level and urinary NO excretion in hypertensive patients were investigated. Blood and urine samples of 16 hypertensive outpatients were collected before and 2 months after cilnidipine therapy (10 mg). The serum uric acid level decreased significantly after cilnidipine treatment, while the uric acid-creatinine clearance ratio was unaffected. The cilnidipine medication produced a significant increase in urinary NO excretion, although amlodipine did not change it significantly. Therefore, cilnidipine has a profound antihypertensive effect and may reduce the serum uric acid level and increase NO production in the kidney.

Allopurinol as a cardiovascular drug

Cardiovascular disease (CVD) remains the leading cause of death in the United States. There is evidence that shows a direct relationship between an elevated uric acid level and an increased risk of cardiovascular (CV) events, which has set the foundation for the investigation of uric acid-lowering drugs for the treatment of CVD. Although traditionally the cornerstone therapy for gout, allopurinol's ability to be a competitive inhibitor of the key enzyme, xanthine oxidase, needed for uric acid formation, has prompted recent clinical research evaluating allopurinol as a CV drug. Epidemiologic and biochemical studies on uric acid formation have shown that it is not only uric acid itself that leads to worsening prognosis and increased CV events, but also the free radicals and superoxides formed during xanthine oxidase activity. The combination of uric acid formation and formed free radicals could ultimately lead to coronary endothelial dysfunction and worsening of myocardial oxidative stress. Along with preventing uric acid formation, allopurinol also has the ability to behave as a free radical scavenger of the superoxide anions and free radicals released during uric acid formation.Clinical studies have shown that allopurinol improves endothelial dysfunction and subsequently improves the exercise capacity in patients diagnosed with angina pectoris. Allopurinol has also been shown to decrease oxidative stress and ameliorate the morbidity and mortality of congestive heart failure patients by possibly improving mechanoenergetic uncoupling, with the enhancement of myocardial contractility and the left ventricular ejection fraction. This review presents the pharmacologic action of allopurinol on the CV system and describes the effectiveness of allopurinol as a potential drug to treat 2 CVD morbidities: ischemic heart disease and congestive heart failure.

Relationship between serum uric acid and cerebral white matter lesions in the elderly

BACKGROUND AND AIMS

Recent evidence suggests that hyperuricemia might increase the risk of cardiovascular disease. Cardiovascular risk factors are well recognized to be associated with cerebral white matter lesion (WML). We hypothesized that hyperuricemia is related to higher grade of WML in both men and women.

METHODS AND RESULTS

A total of 108 men and 123 women were enrolled from those who signed up for the annual Health Examination for the Elderly Program in Taipei from 2006 to 2008. Information in interview data, clinical and laboratory examinations were collected. Hyperuricemia was defined by uric acid ≥458.0 μmol/L in men and ≥392.6 μmol/L in women. Two types of WML including periventricular hyper-intensity (PVH) and deep white matter hyper-intensity (DWMH), ascertained by cranial magnetic resonance imaging, were graded. Association between hyperuricemia and high grade WML was evaluated by using multiple logistic regression analysis. The prevalences of hyperuricemia were 13.9% and 17.9% for men and women, respectively. The prevalences of moderate-to-severe PVH among men and women were 16.7% and 7.3%; while the prevalences of moderate-to-severe DWMH for men and women were 19.4% and 11.4%, respectively. Hyperuricemia was related to moderate-to-severe DWMH in men, after controlling for age, education years, smoking, alcohol consumption, metabolic Z score, silent infarct, and the use of anti-hypertensives, lipid-lowering and anti-diabetic agents, the association remained significant. The relationship was not evident among women. We did not find an association between hyperuricemia and PVH.

CONCLUSIONS

Hyperuricemia was positively associated with high grade DWMH in older men, but not in women.

Allopurinol and global left myocardial function in heart failure patients

Background and Aim:

Increased xanthine oxidase (XO) activity may contribute to heart failure pathophysiology. This study evaluated whether a XO inhibitor, allopurinol produces clinical and functional benefits in patients with New York Heart Association functional class III to IV heart failure due to systolic dysfunction receiving optimal medical therapy as estimated by global left myocardial function.

Patients and Methods:

Fifty-nine patients with a diagnosis of chronic heart failure due to coronary heart disease or idiopathic dilated cardiomyopathy and 20 healthy controls who attended the outpatient clinic of cardiology were subjected to full echocardiographic study including left ventricular diastolic and systolic function, and the combined index of myocardial performance [Tei index: isovolumetric relaxation time (IRT) + isovolumetric contraction time (ICT)/ejection time (ET)]. Patients were randomized to allopurinol (300 mg/day) or placebo. Improvement at 36 weeks was assessed using a composite end point comprising global left cardiac function as well as heart failure morbidity and mortality.

Results:

The percentage of patients characterized as improved, unchanged, or worsened did not differ between those receiving allopurinol or placebo. Allopurinol reduced serum uric acid (SUA) by 1.5 mg/dL (P = 0.001). In a subgroup analysis, patients with elevated SUA (more than 7mg/ dL) responded favorably to allopurinol whereas those with SUA less than 7mg/dL exhibited a trend toward no change. In addition, SUA reduction to allopurinol correlated with favorable clinical and functional response. Within the entire allopurinol patient cohort, those characterized as either improved or unchanged had significantly greater reductions in SUA compared with patients who did not change (P = 0.0007). In placebo patients, lower baseline SUA, but not change in SUA, correlated with improved clinical outcome.

Conclusions:

Allopurinol did not produce significant clinical and functional improvement in unselected patients with moderate-to-severe heart failure. However, it is suggested that it is useful in patients with elevated SUA in a manner according to degree of SUA reduction. SUA may serve as a valuable biomarker to target heart failure therapy.

Effect of allopurinol on blood pressure and aortic compliance in hypertensive patients

BACKGROUND

Arterial hypertension is commonly associated with hyperuricemia. Several studies have shown that allopurinol reduces arterial blood pressure in animal models and in adolescent patients with newly diagnosed hypertension. Moreover, allopurinol has shown beneficial effects on endothelial function and arterial wave reflection in contrast to uricosuric agents. Antihypertensive drugs produce different effects on serum uric acid levels.

OBJECTIVE

The aim of the study was to evaluate the influence of allopurinol on blood pressure and aortic compliance in patients with arterial hypertension depending on hypotensive therapy with angiotensin-converting enzyme inhibitor (ACE-I) or thiazide diuretic, hypotensive drugs with distinct effects on serum uric acid levels and conversely, a positive influence on pulse wave velocity (PWV) in the aorta.

MATERIAL AND METHODS

Sixty-six patients aged 25-70 (mean age 46.17 ± 10.89) with mild and moderate arterial hypertension diagnosed on the basis of office blood pressure, were studied. They were randomized to antihypertensive therapy on either perindopril (n = 35) or hydrochlorothiazide (n = 31). After 8 weeks of antihypertensive therapy, 150 mg of allopurinol daily was added for the next 8 weeks. Measurement of the serum uric acid level, PWV and 24-h ambulatory blood pressure monitoring (ABPM) were performed at baseline, after 8 weeks antihypertensive therapy and again after the final 8 weeks with the additional allopurinol.

RESULTS

No significant changes in systolic (SBP) and diastolic blood pressure (DBP) or ABPM were observed after allopurinol treatment in either of the subgroups receiving ACE-I or thiazide-based antihypertensive therapy. The mean PWV decreased from 10.7 ± 1.4 m/s to 10.0 ± 1.2 m/s (p = 0.00008) in the ACE-I-based therapy subgroup and from 11.5 ± 1.7 m/s to 10.4 ± 1.5 m/s (p = 0.00002) in the thiazide-based therapy subgroup after treatment with allopurinol. However, significant correlations were found between PWV changes and the basic PWV (r = -0.52; p < 0.001) or SBP changes (r = 0.29; p < 0.019) after allopurinol treatment.

CONCLUSIONS

Allopurinol does not produce additional antihypertensive effects in patients with treated arterial hypertension. Allopurinol increases aortic compliance independently of ACE-I or thiazide-based, antihypertensive therapy. However, this effect is significantly dependent on the initial PWV in the aorta and on SBP changes during allopurinol therapy.

Association of serum uric acid with aortic stiffness and pressure in a Chinese workplace setting

BACKGROUND

In the present analysis, we investigated the association of serum uric acid with aortic stiffness and pressure as measured by carotid-femoral pulse wave velocity (cf-PWV) and central systolic blood pressure (SBP), respectively.

METHODS

Our study was conducted in the framework of cardiovascular health examinations for the employees of a factory and their family members (ages 15-79 years). We performed arterial measurements using the SphygmoCor device. Hyperuricemia was defined as a serum uric acid concentration of at least 420 micromol/l in men and 360 micromol/l in women.

RESULTS

The 940 study participants included 207 (22.0%) hypertensive patients, of whom 92 (9.8%) took antihypertensive medication. Men (n = 620), compared with women (n = 320), had significantly (P < or = 0.03) higher serum uric acid concentration (363 +/- 76 vs. 272 +/- 64 micromol/l), prevalence of hyperuricemia (17.9% vs. 7.5%), cf-PWV (7.41 vs. 7.16 m/s), and central SBP (114.4 vs. 108.8 mm Hg). Both before and after adjustment for age, serum uric acid was significantly (P < or = 0.02) and positively associated with cf-PWV and central SBP in all subjects and in men and women separately. After full adjustment for covariates, the association with cf-PWV remained statistically significant (P < or = 0.009) in all subjects and men, and with central SBP in all subjects only. Categorical analyses were confirmatory. In all subjects, patients with hyperuricemia had significantly (P = 0.03) higher cf-PWV (7.51 vs. 7.29 m/s) and central SBP (114.9 vs. 112.1 mm Hg) than those with normal serum uric acid.

CONCLUSIONS

Serum uric acid was associated with aortic stiffness and pressure in a Chinese workplace setting, especially in men.

The potential for xanthine oxidase inhibition in the prevention and treatment of cardiovascular and cerebrovascular disease

There is a now a wealth of epidemiological, animal, and clinical data to suggest the benefits of uric acid reduction and hxanthine oxidase inhibition in prevention of vascular disease. This review discusses the available epidemiological, preclinical, and clinical data and considers arguments for and against a role for serum uric acid in common cardiovascular disorders. It concludes that large scale trials with clinical endpoints are justified to address this important question and to define whether use of drugs such as allopurinol should be a routine part of preventative strategies.

Effects of the Yangtze River source of drinking water on metabolites of Mus musculus

The effects of the Yangtze River source of drinking water on metabolites of mouse (Mus musculus) were implemented to observe the environmental health issue of the water by use of the 1H nuclear magnetic resonance (NMR) spectroscopy-based metabonomics. All the sampled mice were treated for 90 days. There were 20 organic pollutants discovered in the water with total concentration of 9.41 microg/l. The NMR spectra for the sampled mice were different at delta2.06, delta2.24 and delta5.22. The concentrations of alanine, glycoprotein, acetone and trimethylamine-N-oxide in the source water group mice were decreased but that of creatinine and glucose were increased, which indicated that hepatotoxicity and kidney dysfunction occurred. There were six parameters for the source water group mice were different or extremely different from that of the control group. And these metabolites are responsible for separation of the data along PC1 and PC2 which may be used as biomarkers to indicate the source water pollution. The results indicate that 1H NMR-based metabonomic approach is a useful technique to test toxicity of xenobiotics on metabolites for observation of the environmental health issue of source water.

Elevated blood pressure, obesity, and hyperlipidemia

OBJECTIVES

To investigate the association of blood pressure elevation with body mass index (BMI) and total cholesterol levels in children who screened positive for proteinuria, glucosuria, and/or hamaturia.

STUDY DESIGN

From 1992 to 2000, a mass urine screening program was conducted annually for nearly 3,000,000 students aged 6 to 18 years. Of 99,350 students with positive results on urine tests, further examination found 17,548 students (17.7%) had blood pressure elevation. A case-control analysis was performed with randomly selected subjects with normal blood pressure who were frequency matched by sex and age.

RESULTS

The adjusted odds ratio for blood pressure elevation in obese students was 3.45 (95% CI, 3.20-3.72), compared with students of normal weight. The odds ratio for blood pressure elevation increased to 6.15 (95% CI, 4.12-9.18) for students with a total cholesterol level > or =250 mg/dL and obesity, compared with students with a total cholesterol level <200 mg/dL and normal weight.

CONCLUSION

This study found a high prevalence of elevated blood pressure in children with abnormal urinalysis results, with a strong association with BMI and total cholesterol level.

The role of uric acid in stroke: the issue remains unresolved

BACKGROUND

Although in the past decade a large number of studies have been performed to identify the relationship between uric acid and stroke, the issue remains unresolved and it is not clear whether the correlation between uric acid and stroke is circumstantial or causal.

REVIEW SUMMARY

Some studies have found uric acid predictive for the development of cardiovascular disease, whereas others have failed to identify uric acid as a significant and independent risk factor after controlling for other atherosclerotic risk factors. Furthermore, uric acid, a powerful endogenous antioxidant, is increased in oxidative stress situations such as stroke. Still, it remains controversial whether elevated serum uric acid is neuroprotective or injurious at the onset of acute stroke.

CONCLUSIONS

Large trials are required to provide definite answers in clinical practice and to reevaluate the goals of hypouricemic treatment in subjects with increased cardiovascular risk or during an acute cardiovascular event like stroke. This review tries to keep pace with the data concerning the association between uric acid and stroke.

Relationship between silent brain infarction and chronic kidney disease

Background. The presence of silent brain infarction (SBI) increases the risk of symptomatic stroke and dementia. The association between SBI and chronic kidney disease (CKD) has not been clarified. Moreover, little is known about what factors are related to SBI in CKD patients and whether the prevalence of SBI differs in CKD stage or cause of CKD.

Methods. This is a cross-sectional study. A total of 375 subjects—335 with CKD and 40 with essential hypertension—were included. All subjects underwent magnetic resonance imaging (MRI) of the brain to detect SBI. Glomerular filtration rate (GFR) was estimated using Modification of Diet in Renal Disease equation, and cardiovascular risk factors were examined.

Results. The prevalence of SBI was 56.5% in all subjects. Among causes of CKD, hypertensive nephrosclerosis had a strong association with SBI. According to the estimated GFR (eGFR) stage, the more severe the stage of eGFR, the higher the prevalence of SBI (age-adjusted odds ratio [95% confidence interval] for eGFR 30–59, 15–29 and <15 versus ≥60 mL/min/1.73 m²: 1.34 [0.68–1.99], 1.94 [1.30–2.57] and 2.51 [1.91–3.10]). In multivariate logistic analysis, eGFR was related to SBI independently, in addition to age and blood pressure (P = 0.025). However, other traditional and non-traditional risk factors were not.

Conclusion. There was an independent association between eGFR and SBI. CKD patients should receive active detection of SBI and more intensive preventive management, especially for hypertension, should be needed in CKD patients to prevent SBI.