Plasma uric acid and hypertension in a Chinese community: prospective study and metaanalysis

Correlation between hyperuricemia and thickened left ventricular wall in hypertensive young adults

BACKGROUND

In this study, we examine the association between the hyperuricemia(HU) and hypertension(HTN) in Chinese young adults. Besides, the correlation between the occurrence of thickened left ventricular wall and HU was identified in patients with HTN.

METHODS

In all, 360 patients with HTN and 1991 young adults with normal blood pressure(NBP) were enrolled in the study. Participant characteristics were collected. Univariable and multivariable logistic regression tests were utilized to identify the correlation between the presence of HU and HTN, and the correlation between the occurrence of thickened ventricular septum and HU in patients with HTN.

RESULTS

The prevalence of HU in Chinese young adults with HTN was significantly higher than young adults with NBP(36.39% vs. 16.93%). Univariable analyses revealed that 8 factors were related with the presence of HTN with p value < 0.001, including HU, male, body mass index(BMI) ≥ 24 kg/m2, total cholesterol(TC) > 5.17mmol/L, triglyceride(TG) > 1.70mmol/L, high density lipoprotein cholesterol(HDL-C) < 1.0mmol/L, fasting blood glucose(FBG) > 6.10mmol/L and fatty liver. After adjusting these covariates, multivariable analysis revealed that HU[odds ratio(OR):1.47, 95% confidence interval(CI): 1.10-1.95, p = 0.008] remained independent association with HTN in young adults. Additionally, univariable and multivariable logistic analyses revealed that HU kept the independent effect on the presence of thickened interventricular septum(adjusted OR = 1.81, 95% CI: 1.05-3.11, P = 0.03) and thickened left ventricular posterior wall(adjusted OR = 2.28, 95% CI: 1.28-4.08, P = 0.005) in young adults with HTN.

CONCLUSION

HU was independently associated with HTN in young adults. HU was independently correlated with thickened left ventricular wall, including interventricular septum and left ventricular posterior wall, in young adults with HTN.

Correlation between serum uric acid and body fat distribution in patients with MAFLD

BACKGROUND

Metabolic dysfunction associated with fatty liver disease (MAFLD) is often correlated with obesity and hyperuricemia. The present study aimed to determine the association between serum uric acid (SUA) and central fat distribution in patients with MAFLD.

METHODS

A total of 485 patients were classified into the following groups: (1) controls without MAFLD and hyperuricemia (HUA), (2) MAFLD with normal SUA, and (3) MAFLD with HUA. DUALSCAN HDS-2000 was used to measure visceral fat (VAT) and subcutaneous fat (SAT). Dual-energy X-ray absorptiometry (DEXA) was used to measure body fat distribution.

RESULTS

MAFLD patients with HUA had remarkably higher BMI, fasting insulin, OGIRT AUC, ALT, AST, TG, VAT, SAT, Adipo-IR, trunk fat mass, android fat, and total body fat than MAFLD patients with normal SUA (all p < 0.05). The increase in VAT, SAT, CAP, Adipo-IR, upper limbs fat mass, trunk fat mass, and android fat, as well as the percentage of MAFLD, were significantly correlated with the increase in SUA. The percentage of MAFLD patients with HUA increased significantly with increasing VAT or SAT, as determined by the Cochran-Armitage trend test (all p < 0.05). Furthermore, VAT (OR = 1.01 CI: 1.00, 1.03; p < 0.05) and adipo-IR (OR = 1.09 CI: 1.00, 1.19; p < 0.05) were associated with circling SUA in MAFLD after adjusting for sex, age, TG, TC, HOMA-IR, and BMI.

CONCLUSION

Abdominal fat promotes the co-existence of HUA and MAFLD, while weight loss, especially, decreasing VAT, is of great importance to decrease SUA levels and manage MAFLD.

Hyperuricemia and kidney damage in patients with cardiovascular disease: A review

Many studies have been conducted confirming the effect of uric acid (UA) on kidney function. It is obvious that there is a relationship between the effect of UA not only on kidney function, but also on the cardiovascular system, increasing cardiovascular risk. The review article provides basic information about the pathogenesis, principles and features of prescribing therapy to patients with chronic kidney disease (CKD) and cardiovascular disease. A lot of data currently indicates that hyperuricemia, both with and without crystal deposition, is associated with high cardiovascular risk and decreased kidney function. A number of studies and meta-analyses indicate that urate-reducing therapy prevents and slows down the decline in kidney function in patients with CKD, many of whom suffer from cardiovascular diseases or at least have several risk factors. Despite the fact that currently the guidelines for the treatment of CKD do not include a recommendation for the start of urate-lowering therapy, a large amount of data has been accumulated on the potential benefits of such treatment even in the absence of a diagnosis of gout. The preferred group of drugs for this group of patients are xanthine oxidase inhibitors, and for patients with eGFR below 30 ml/min/1.73 m2, it seems that allopurinol currently has larger evidence base for the efficacy and safety of prescribing.

Association between Serum Uric Acid and Hypertension in Han and Yugur of Gansu Province: The China National Health Survey

INTRODUCTION

Serum uric acid (SUA) has been found correlated with an increased risk of hypertension, but evidence is sparse regarding the association in Gansu Province, especially in Yugur people. This study aimed to explore the nonlinear relationship between SUA levels and hypertension in Han and Yugur people in China.

METHODS

The cross-sectional study samples (n = 5,327) were from the China National Health Survey (CNHS) in Gansu Province. Participants were selected using a multistage stratified cluster sampling method. SUA was measured by enzymatic methods. The restricted cubic spline regression was performed to evaluate the shape of the association.

RESULTS

The overall prevalence of hypertension and hyperuricemia was 28.4% and 17.0%, respectively, in this study. Comparing the highest (>416.4 μmol/L) to the lowest (<254.1 μmol/L) SUA level groups, the multivariable adjusted differences and 95% confidence intervals (CIs) in blood pressure (BP) were 6.15 (4.22, 8.08) mm Hg and 4.87 (3.51, 6.23) mm Hg for SBP and DBP in Han, and 2.22 (-0.73, 5.18) mm Hg and 2.56 (0.38, 4.75) mm Hg for SBP and DBP in Yugur people, respectively. The corresponding odds ratios (95% CIs) for hypertension were 3.16 (2.26, 4.43) and 2.37 (1.46, 3.89) in Han and Yugur people, respectively. The restricted cubic spline regression models illustrated that both BP level and the risk of hypertension increased with elevated SUA levels in Han and Yugur people.

CONCLUSIONS

SUA was significantly and independently associated with an increased risk of hypertension in Han and Yugur people. Prospective studies are needed to confirm these findings.

Dose-response association between serum uric acid levels and incident hypertension: a systematic review and meta-analysis of 17 prospective cohort studies of 32 thousand participants

BACKGROUND

Various magnitudes of the risk of incident hypertension (IHTN) have been reported to be associated with increased serum uric acid (SUA) levels in observational studies, however, whether a dose-response relation exists is unclear. We aimed to quantitatively evaluate the SUA-IHTN association.

METHODS

We searched the PubMed and Embase databases for relevant articles published prior to 21 October 2019. Random-effects models were used to estimate the summary relative risks (RRs) and 95% confidence intervals (CIs) of the IHTN risk in relation to SUA levels. We used restricted cubic splines to model the dose-response association between SUA levels and IHTN.

RESULTS

A total of 17 articles (17 prospective cohort studies) including 321,716 adults and 65,890 IHTN cases were identified. The pooled RR was 1.10 (95% CI 1.07-1.13; I²=90.7%; n = 17) per 1 mg/dL change in the SUA level. In addition, we found evidence of a linear and positive dose-response association between SUA levels and IHTN (P_{non-linearity} = 0.069). The results of the subgroup and sensitivity analyses were consistent with those of the primary analysis.

CONCLUSION

These data suggested that people with higher SUA levels had a higher IHTN risk. SUA levels need to be controlled to reduce or eliminate the risk of IHTN associated with SUA levels. Clinical trial studies or diagnostic studies are needed to determine the optimal cut-off point for SUA.

Sex-Specific Association of Uric Acid and Kidney Function Decline in Taiwan

An elevated serum urate concentration is associated with kidney damage. Men’s uric acid levels are usually higher than women’s. However, postmenopausal women have a higher risk of gout than men, and comorbidities are also higher than in men. This study examined the sex differences in the relationship between hyperuricemia and renal progression in early chronic kidney disease (CKD) and non-CKD, and further examined the incidence of CKD in non-CKD populations among patients over 50 years of age. We analyzed 1856 women and 1852 men participating in the epidemiology and risk factors surveillance of the CKD database. Women showed a significantly higher risk of renal progression and CKD than men within the hyperuricemia group. After adjusting covariates, women, but not men resulted in an hazard ratio (HR) for developing renal progression (HR = 1.12; 95% CI 1.01–1.24 in women and HR = 1.03; 95% CI 0.93–1.13 in men) and CKD (HR = 1.11; 95% CI 1.01–1.22 in women and HR = 0.95; 95% CI 0.85–1.05 in men) for each 1 mg/dL increase in serum urate levels. The association between serum urate levels and renal progression was stronger in women. Given the prevalence and impact of kidney disease, factors that impede optimal renal function management in women and men must be identified to provide tailored treatment recommendations.

Levels and Predictors of Self-Care Among Patients with Hypertension in Pakistan

Background

Globally, hypertension is the leading non-communicable disease and strongest predictor of cardiovascular diseases. To mitigate and prevent hypertension-related complications, self-care behavior adaptation has proven to be vital. In this study, we examined the six clinically prescribed levels of self-care as prescribed by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure and its predictors among a select sample of hypertensive individuals in Karachi, Pakistan.

Methods

This study reports the cross-sectional survey of a sequential mixed method study which assessed the levels of self-care of hypertensive individuals residing in an urban cosmopolitan setting within Karachi Pakistan. Four hundred and two patients were screened using the H-SCALE questionnaire, while socio-demographic predictors of self-care and level of knowledge of hypertension were identified using a study-specific checklist. Self-care was assessed against six clinical domains including medication adherence, diet, weight management, physical activity, and abstinence from alcohol.

Results

Participants were recruited from the two largest tertiary care hospitals in Karachi. Good knowledge about hypertension, including its causes, management, and complications was reported by 4.47% of the participants. Highest levels of self-care adherence were found for abstinence from alcohol (100%), smoking cessation (83.33%), and medication compliance (71.89%), whereas lowest levels were found for diet (27.11%), and physical activity (24.88%). In terms of predictors for self-care, age, male gender, and self-checking of blood pressure at home, followed by the level of education were the most common predictors for each self-care behavior in the given population.

Conclusion

Overall knowledge of self-care for hypertension is sub-optimal among hypertensive patients in Pakistan which is reflected in their behaviors. There is a need to introduce healthcare educational programs in Pakistan which can improve self-care behaviors of hypertensive individuals and potentially reduce the prevalence of associated cardiovascular diseases and its complications.

Incidence and Risk Factors of Hyperuricemia among 2.5 Million Chinese Adults during the Years 2017-2018

Objective: To assess the incidence and risk factors of hyperuricemia among Chinese adults in 2017-2018. Methods: A total of 2,015,847 adults (mean age 41.2 ± 12.7, 53.1% men) with serum uric acid concentrations assayed on at least two separate days in routine health examinations during 2017-2018 were analyzed. Hyperuricemia was defined as fasting serum urate concentration >420 μmol/L in men and >360 μmol/L in women. The overall and sex-specific incidence rate were stratified according to age, urban population size, geographical region, annual average temperature and certain diseases. Logistic regression analyses were performed to explore risk factors associated with hyperuricemia. Results: 225,240 adults were newly diagnosed with hyperuricemia. The age- and sex-standardized incidence rate per 100 person-years was 11.1 (95%CI: 11.0-11.1) (15.2 for men and 6.80 for women). The risk of hyperuricemia was positively associated with younger age, being male, larger urban population size, higher annual temperature, higher body mass index, lower estimate glomerular filtration rate, hypertension, dyslipidemia and fat liver. Conclusions: The incidence of hyperuricemia was substantial and exhibited a rising trend among younger adults, especially among men. Socioeconomic and geographic variation in incidence were observed. The risk of hyperuricemia was associated with estimate glomerular filtration rate, fat liver and metabolic factors.

Reference intervals for routine biochemical markers and body mass index: A study based on healthcare center database in northeastern Iran

Age- and sex-specific reference intervals (RIs) for some biochemical tests may be useful for their interpretation, due to the variations in lifestyle and genetic, or ethnic factors. The aim of this study was to obtain RIs for some routine biochemical markers including a serum lipid profile, fasting blood glucose (FBG), aspartate and alanine aminotransferase (AST and ALT), uric acid, and body mass index (BMI) in subjects who attended primary healthcare centers. The large database of primary healthcare centers uses RIs to report results for children, adolescents, and young and old adults. RIs were obtained by using the indirect method, recommended by the CLSI Ep28-A3 guidelines. RIs for FBG, BMI, and serum lipid profile, including triglyceride, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol in people aged 18 to 120 years, were obtained without age/sex segmentation. RIs for serum AST, ALT, and uric acid were obtained without age segmentation, though these RIs were higher in males than females. The RIs for AST, ALT, and uric acid were higher in men, while the RIs for the other variables were similar in both sexes. This is the first study reporting the use of indirect RIs for BMI.

[Asymptomatic Hyperuricemia and Risk Of Cardiovascular and Renal Diseases]

Asymptomatic hyperuricemia (HU) is common in the population and significantly contributes to the general cardiovascular risk. Despite extensive study of this condition there is still no conclusive answers to questions about detection of asymptomatic HU and its effect on the risk for development and progression of cardiovascular and kidney diseases. This review summarizes key information about these issues, which has been accumulated by the present time.

High serum uric acid within the normal range is a useful predictor of hypertension among Japanese community-dwelling elderly women

Background

The risk associated with serum uric acid (SUA) levels when within the normal range is unknown. This study aims to examine whether SUA within the normal range is a predictor of hypertension.

Methods

The subjects comprised 704 men aged 71 ± 9 (mean ± standard deviation) years and 946 women aged 70 ± 8 years recruited for a survey at the community based annual medical check-up. The main outcome was the presence of hypertension (antihypertensive medication and/or having SBP ≥140 mmHg and/or DBP ≥90 mmHg).

Results

At baseline, 467 (66.3%) men and 608 (64.3%) women had hypertension. Comparing to lowest quartile in women (SUA-1, uric acid < 4.1 mg/dL), the unadjusted odds ratios (ORs) [95% confidence interval (CI)] for hypertension of SUA-2 (4.1 to 4.7 mg/dL), SUA-3 (4.8 to 5.4 mg/dL), and SUA-4 (≥5.5 mg/dL) were 1.11 (0.78–1.59), 1.75 (1.20–2.55), and 1.89 (1.30–2.77), respectively. These associations were apparent even after adjustments for age, but ORs were attenuated after adjusting for all confounding factors. During a follow-up of 3.0 years, there were 35 (24.0%) hypertension cases in men and 51 (20.8%) in women. In women only, a significant association between increased SUA categories and incidence of hypertension was observed, and the multivariate-ORs (95% (CI) for incident hypertension of SUA-3 (4.5–5.2 mg/dL) and SUA-4 (≥5.3 mg/dL) were 2.23 (0.81–6.11) and 3.84 (1.36–10.8), respectively.

Conclusions

These results suggest that baseline SUA within the normal range could be an important predictor for incidence of hypertension in Japanese community-dwelling elderly women.

Association of serum uric acid, morning home blood pressure and cardiovascular risk factors in a population with previous prehypertension: a cross-sectional study

OBJECTIVE

To observe the changes in blood pressure (BP) over 10 years and to investigate current BP association to serum uric acid (SUA) levels and cardiovascular risk factors in the epidemiological data of a target group of patients with prehypertension in 2007.

DESIGN

Cross-sectional study.

SETTING

Mlati Subdistrict, Sleman District, Yogyakarta Province, Indonesia.

PARTICIPANTS

A total of 733 patients from 'Mlati Study Database' in 2007 were selected by simple random sampling using statistical software. Subjects had both physical and laboratory examinations.

OUTCOME MEASURES

Morning home BP and laboratory examination of urine (uric acid excretion and creatinine) and blood samples (SUA, blood urea nitrogen, creatinine, a lipid profile and fasting blood glucose levels).

RESULTS

About 31.1% of 733 subjects with prehypertension became hypertensive after 10 years, 24.6% returned to normal tension and the rest of it remained in prehypertensive state. Mean (SD) of SUA levels in 2017 was significantly higher in men than in women (5.78 (1.25) mg/dL vs 4.52 (1.10) mg/dL, p<0.001). Furthermore, men tended to have high-normal (5-7 mg/dL) or high SUA levels (≥7 mg/dL) compared with women (p<0.001, Relative Risk (RR)=2.60). High-normal and high SUA levels in population with a history of prehypertension were significantly associated with current prehypertension and hypertension only in women (p=0.001, RR=1.21). Age and body mass index was found to be significantly associated with both systolic and diastolic BP in men, but only with systolic BP in women. Fasting blood glucose and SUA levels were significantly associated with systolic and diastolic BP only in women.

CONCLUSION

We concluded that after 10 years, of 733 subjects with prehypertension, 31.1% became hypertensive. The SUA levels in men are significantly higher than those in women. Moreover, high-normal and high SUA levels were significantly associated with prehypertension and hypertension in women but not in men.

Uric acid is independent and inversely associated to glomerular filtration rate in young adult Brazilian individuals

BACKGROUND AND AIMS

Uric acid, the end-product of human purine metabolism, is associated with hypertension, diabetes and obesity. It has also been independently associated with the onset of chronic kidney disease in several populations. In this study, the association between serum uric acid (SUA) level and estimated glomerular filtration rate (eGFR) was investigated in healthy individuals belonging to two Brazilian birth cohorts.

METHODS AND RESULTS

Data from 3541 to 3482 individuals, aged 30 and 22-years old, respectively, was included. eGFR was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine measurement. Regression analyses were sex-stratified due to interaction between SUA and sex (p < 0.001) and adjusted for perinatal, cardiometabolic and behavioral variables. We observed an inverse association between eGFR and SUA even after adjustment. In the highest tertile (3rd) of SUA, the eGFR coefficients at 30-years were-0.21 (95%CI -0.24;-0.18) for men and -0.20 (95%CI -0.23; -0.17) for women; at 22-years, were -0.09 (95%CI -0.12;-0.05) for men and -0.13 (95%CI -0.15; -0.10) for women. Higher differences among exponential means (95% CI) of eGFR between the 1st and the 3rd tertile of SUA were seen in older participants, being more pronounced in men. At 22-years, the highest difference was found in women.

CONCLUSIONS

In young healthy individuals from a low-middle income country, SUA level was inversely associated with eGFR. Gender-related differences in eGFR according tertiles of SUA were higher in men at 30-years and in women at 22-years.

Uric Acid and Prevalence of Hypertension in a General Population of Japanese: ISSA-CKD Study

Background

There is uncertainty surrounding the causal relationship between serum uric acid and hypertension. The aim was to investigate the association between serum uric acid and prevalence of hypertension in a general population of Japanese.

Methods

This was a population-based cross-sectional study using health check-up data of the residents of the Iki City, Nagasaki Prefecture, Japan. A total of 7,484 participants aged 30 years or older were included in this study. Serum uric acid was classified into four groups: group 1 (< 357 µmol/L (< 6 mg/dL)), group 2 (357 - 415 µmol/L (6 - 6.9 mg/dL)), group 3 (416 - 475 µmol/L (7 - 7.9 mg/dL)) and group 4 (≥ 476 µmol/L (≥ 8 mg/dL)). Hypertension was defined as blood pressure (BP) levels of ≥ 140/90 mm Hg or use of BP lowering medications.

Results

Hypertension was observed among 3,467 participants (prevalence 46.3%). The prevalence of hypertension increased with elevation of serum uric acid levels: 42.8% in group 1, 55.0% in group 2, 57.6% in group 3 and 59.8% in group 4 (P < 0.001 for trend). This association was significant even after adjustment for other risk factors including age, sex, current smoking, current alcohol intake, obesity, diabetes, dyslipidemia, estimated glomerular filtration rate and proteinuria: odds ratios (95% confidence intervals) were 1.50 (1.28 - 1.77) for group 2, 1.58 (1.25 - 1.99) for group 3 and 1.89 (1.36 - 2.64) for group 4 compared with the reference group of group 1 (P < 0.001 for trend).

Conclusions

Serum uric acid was clearly associated with prevalence of hypertension in a general population of Japanese.

Effect of febuxostat on blood pressure in hyperuricemic patients: A protocol for a systematic review and meta-analysis

BACKGROUND

Increasing evidence connects serum uric acid (sUA) with hypertension. Previous studies on the efficacy of febuxostat on blood pressure (BP) in hyperuricemic patients have provided conflicting results. Thus, we aim to perform a systematic review and meta-analysis to investigate the efficacy of febuxostat on BP.

METHODS

Five electronic databases (included The Cochrane Library, MEDLINE, Embase, Web of Science, and Cochrane Central Register of Controlled Trials) will be searched. Randomized controlled trials will be included if they recruited hyperuricemic participants for assessing the effect of febuxostat on BP versus control (placebo, no treatment, and other therapeutic agents). The primary outcome will be BP, secondary outcomes will be sUA, serum creatinine, and estimated glomerular filtration rate. Relevant literature search, data extraction, and quality assessment will be performed by 2 researchers independently, and the third researcher will be involved in a discussion for any disagreements. All analyses will be performed based on the Cochrane Handbook for Systematic Reviews of Interventions. Stata 12.0 software will be used for statistical analysis. The effect size of dichotomous data will be measured using the odds ratio , and the effect size of continuous data will be measured using the standardized mean difference. And 95% confidence intervals will be calculated. Heterogeneity will be tested by χ-based Cochran Q statistic and I statistic. Sensitivity analysis and subgroup analysis will be used to observe changes in the pooled effect size and heterogeneity between included studies, to assess the reliability and stability of the pooled results. The funnel plot and Egger's and Begg's tests will be used to judge publication bias, and the trim and fill method will be used to correct the funnel asymmetry caused by publication bias. P < .05 will be considered to indicate a statistically significant result.

RESULTS

This systematic review and meta-analysis will be to assess the efficacy of febuxostat on BP.

CONCLUSIONS

Our findings will show the effect of febuxostat on BP in hyperuricemic patients. And such a study may find a new therapeutic option for hypertensive patients and assist clinicians and health professionals make clinical decisions.

ETHICS AND DISSEMINATION

This study is a protocol for systematic review and meta-analysis of the effect of febuxostat on BP in hypertensive patients. This systematic review and meta-analysis will be published in a journal and disseminated in print by peer-review.

INPLASY REGISTRATION NUMBER

INPLASY202050031.

The Association between Serum Uric Acid and Peripheral Neuropathy in Patients with Type 2 Diabetes Mellitus: A Multicenter Nationwide CrossSectional Study

Background

The role of uric acid in the development of diabetic peripheral neuropathy remains unclear. This study aimed to determine the association between uric acid and peripheral neuropathy among type 2 diabetes mellitus (T2DM) patients.

Methods

We conducted a nationwide cross-sectional study based on the diabetes and hypertension study of the Medical Research Network of the Consortium of Thai Medical Schools. Adult T2DM patients from 831 public hospitals in Thailand were evaluated. The serum uric acid level was categorized into five groups based on quintiles (<4.4, 4.4–5.3, 5.3–6.2, 6.2–7.3, and >7.3 mg/dL). A multivariate logistic regression model was used to assess the independent association between serum uric acid level and peripheral neuropathy.

Results

In total, 7,511 T2DM patients with available data about serum uric acid levels were included in the analysis. The mean age of the participants was 61.7±10.9 years, and approximately 35.6% were men. The prevalence rate of peripheral neuropathy was 3.0%. Moreover, the prevalence rates of peripheral neuropathy stratified according to uric acid levels <4.4, 4.4–5.3, 5.3–6.2, 6.2–7.3, and >7.3 mg/dL were 2.5%, 2.8%, 2.4%, 2.5%, and 4.7%, respectively. A serum uric acid level ≥7.3 mg/dL was found to be associated with an increase in odds ratio (1.54; 95% confidence interval, 1.02–2.32) for peripheral neuropathy compared with a serum uric acid level <4.4 mg/dL.

Conclusion

Serum uric acid level is independently associated with peripheral neuropathy in T2DM patients, and elevated serum uric acid levels should be considered a risk factor for diabetic peripheral neuropathy in clinical practice.

Characteristics of the urinary microbiome in kidney stone patients with hypertension

Background

Kidney stone disease (KSD) is more common in individuals with hypertension (HTN) than in individuals with normotension (NTN). Urinary dysbiosis is associated with urinary tract disease and systemic diseases. However, the role of the urinary microbiome in KSD complicated with HTN remains unclear.

Methods

This study investigated the relationship between the pelvis urinary microbiome and blood pressure (BP) in patients with KSD co-occurring with HTN (KSD-HTN) and healthy controls (HC) by conducting 16S rRNA gene sequencing of bacteria in urine samples. The urine samples were collected (after bladder disinfection) from 50 patients with unilateral kidney calcium stones and NTN (n = 12), prehypertension (pHTN; n = 11), or HTN (n = 27), along with 12 HCs.

Results

Principal coordinates analysis showed that there were significant differences in the urinary microbiomes not only between KSD patients and HCs but also between KSD-pHTN or KSD-HTN patients and KSD-NTN patients. Gardnerella dominated in HCs, Staphylococcus dominated in KSD-NTN patients and Sphingomonas dominated in both KSD-pHTN and KSD-HTN patients. The abundance of several genera including Acidovorax, Gardnerella and Lactobacillus was correlated with BP. Adherens junction and nitrogen and nucleotide metabolism pathways, among others, were associated with changes in BP.

Conclusions

The findings suggest that patients with KSD complicated with HTN have a unique urinary microbiome profile and that changes in the microbiome may reflect disease progression and may be useful to monitor response to treatments.

Association of serum uric acid with visceral, subcutaneous and hepatic fat quantified by magnetic resonance imaging

Elevated serum uric acid (SUA) is associated with a variety of medical conditions, such as hypertension, diabetes and obesity. Analyses investigating uric acid and obesity were primarily conducted using anthropometric measures like BMI and waist circumference. However, different adipose tissue depots might be differentially affected in uric acid metabolism. We analyzed the relation of SUA with visceral, subcutaneous and hepatic fat as quantified by Magnetic Resonance Imaging in N = 371 individuals from a cross-sectional sample of a population-based cohort. Associations of SUA and fat depots were calculated by regressions adjusted for potential confounders. We found that SUA was correlated with all fat measures (e.g. Pearson’s r between SUA and hepatic fat: 0.50, 95%-CI: 0.42, 0.57). Associations with visceral and hepatic fat, but not with subcutaneous fat, remained evident after adjustment for anthropometric measures (e.g. visceral fat: β = 0.51 l, 95%-CI: 0.30 l, 0.72 l). In conclusion, these results show how different adipose tissue compartments are affected by SUA to varying degrees, thus emphasizing the different physiological roles of these adipose tissues in uric acid metabolism.

Hyperuricemia Inhibition Protects SD Rats Against Fructose-Induced Obesity Hypertension Via Modulation of Inflammation and Renin-Angiotensin System in Adipose Tissue

OBJECTIVE

The present study was aimed to reveal the relationship between uric acid and fructose-induced obesity hypertension and its mechanisms.

METHODS

A rat model with obesity hypertension was induced by a high-fructose diet. In the experiment I, the rats were fed with fructose for 8 wks along with allopurinol or benzbromarone at the beginning. In the experiment II, the rats were fed with fructose for 8 wks firstly. And then, these rats were treated with allopurinol or benzbromarone for additional 6 wks.

RESULTS

Fructose-fed rats showed hyperuricemia, abdominal obesity hypertension and an activation in adipose renin-angiotensin system (RAS). Also, fructose-fed rats had higher levels of proinflammatory cytokines and more macrophages infiltrating in adipose tissue. In the experiment I, allopurinol and benzbromarone significantly reduced serum uric acid at 8 wk. Adipose RAS overactivation, adipose inflammatory responses and the development of obesity hypertension were all effectively prevented by hyperuricemia inhibition. In the experiment II, 6-wk treatment with allopurinol and benzbromarone significantly decreased serum uric acid, downregulated adipose RAS, abolished adipose inflammation and improved obesity hypertension.

CONCLUSION

In conclusion, urate-lowering therapy protects rats against fructose-induced obesity hypertension. The mechanisms appear to be via downregulated adipose RAS and reduced inflammation in adipose tissue.

Association between serum uric acid and chronic kidney disease in patients with hypertension: A multicenter nationwide cross-sectional study

INTRODUCTION

Current data on the role of hyperuricemia as a risk factor for renal progression in patients with hypertension is inconclusive. This study aimed to assess the association of uric acid and chronic kidney disease (CKD) in hypertensive patients using a nationwide patient sample.

METHODS

We conducted a nationwide cross-sectional study based on the DM/HT study of the Medical Research Network of the Consortium of Thai Medical Schools. This study evaluated adult patients with hypertension from 831 Thailand public hospitals in the year 2014. Serum uric acid (SUA) was categorized into quintiles (≤4.5, 4.6 to 5.4, 5.5 to 6.2, 6.3 to 7.4, ≥7.5 mg/dL). CKD was defined as estimated glomerular filtration rate of ≤ 60 mL/min/1.73 m² . Multivariate logistic regression was performed to assess the association between SUA and CKD using uric acid of ≤4.5 mg/dL as the reference group.

RESULTS

A total of 9776 hypertensive patients with available SUA were included in the analysis. The mean SUA was 6.1±1.8 mg/dL. The prevalence of CKD in hypertensive patients was 31.8%. SUA of 4.6 to 5.4, 5.5 to 6.2, 6.3 to 7.4, and ≥7.5 mg/dL were associated with an increased CKD with ORs of 1.57 (95% CI 1.28 to 1.92), 2.15 (95% CI 1.74 to 2.66), 3.31 (95% CI 2.72 to 4.04), and 7.11 (95% CI 5.76 to 8.78), respectively. The restricted cubic spline showed significant increased CKD prevalence when uric acid ≥4.6 mg/dL.

CONCLUSION

Higher SUA was associated with increased CKD prevalence in patients with hypertension. SUA should be monitored in hypertensive patients for CKD prevention.

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

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

Prevalence and factors associated with fast resting heart rate in hypertensive and normotensive patients

Background: Fast resting heart rate (RHR) is easily neglected in clinical practice of hypertension treatment.Aims: We aimed to investigate the prevalence of fast RHR and associated factors in hypertensive and normotensive individuals.Methods: We retrospectively analyzed data from two cross-sectional studies conducted in China. A total of 6763 hypertensive patients and 2807 age and sex-matched normotensive subjects with complete data on resting electrocardiogram and medical history were included. Fast RHR was defined as RHR > 85 bpm.Results: The prevalence of fast RHR was higher in hypertensive patients as compared with the normotensives (14.4% vs 7.1%, P < 0.01). In both hypertensive and normotensive subjects, fast RHR appeared as a "U-type" distribution as aging and a "inverted J type" trend as body mass index (BMI) increasing. Multivariate regression analysis showed that fast RHR was associated with age >65 or <25 years old (OR = 1.32, 95% CI 1.08-1.61), BMI <18.5 kg/m² (OR = 2.94, 95%CI 1.47-5.87) and hypercholesterolemia (OR = 1.30, 95%CI 1.10-1.53) in hypertensive patients. Fast RHR in the normotensives was associated with female (OR = 1.78, 95%CI 1.27-2.48), pre-hypertensive state (OR = 2.38, 95%CI 1.61-3.52), and rural area origin (OR = 1.50, 95%CI 1.01-2.42). Stroke and diabetes conferred closer relevance to fast RHR in both hypertensive (OR = 1.31, 95%CI 1.02-1.69 and OR 2.26, 95%CI 1.60-3.21) and normotensive individuals (OR = 2.67, 95%CI 1.36-5.21 and OR = 2.77, 95%CI 1.47-5.23).Conclusion: Fast RHR might be common in patients with hypertension. Prior stroke and diabetes history is common associated with fast RHR. Other factors associated with fast RHR seem to be different between hypertensive patients and normotensive subjects.Abbreviations: BMI: body mass index; CI: Confidence Interval; DBP: diastolic blood pressure; ECG: electrocardiogram; OR: odd ratio; RHR: resting heart rate; SBP: systolic blood pressure.

High serum uric acid is associated with oxidation of nucleosides in patients with type 2 diabetes

Uric acid presents different roles in an organism, since it can act as an antioxidant or a pro-oxidant molecule. High serum uric acid levels may cause damage to several structures, including nucleic acids and its components. Therefore, in this study the association between increased serum uric acid concentrations and oxidation of nucleosides was investigated by assessment of urinary 8-hydroxydeoxyguanosine (8-OHdG) in patients with type 2 diabetes (T2D) and in healthy individuals. Urinary 8-OHdG and biochemical parameters were assessed in 61 patients who were initially grouped into 2 groups based on the median serum uric acid levels (<5.3 mg/dL and ≥5.3 mg/dL). Urinary 8-OHdG was higher in patients with T2D and serum uric acid levels ≥5.3 mg/dL, when compared with the patients with serum uric acid levels <5.3 mg/dL; however, co-occurrence of high serum uric acid with high urinary 8-OHdG was not observed in healthy individuals. A significant positive correlation between 8-OHdG and uric acid (r = 0.40, P < 0.01) was observed in patients with T2D. High serum uric acid levels were associated with high urinary 8-OHdG levels in patients with T2D, and this association was independent of gender, hypertension, body mass index, and serum creatinine.

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.

Association between serum uric acid and atrial fibrillation: a cross-sectional community-based study in China

OBJECTIVES

To investigate the effects of gender on the association of serum uric acid (SUA) levels and atrial fibrillation (AF) prevalence in a community-based Chinese population.

SETTING

Data were obtained from annual Jidong Oilfield employee and family member health checkups. The Jidong community is geographically located in Tangshan City in northern China.

PARTICIPANTS

A total of 9078 residents were invited to take part in the survey and provided informed consents. Individuals without data of ECG or SUA were excluded, leaving 8937 residents in our study.

PRIMARY AND SECONDARY OUTCOME MEASURES

SUA was measured at baseline using the uricase-peroxidase method. Hyperuricaemia was defined as a SUA level >7.0 mg/dL in men and >5.7 mg/dL in women. AF was diagnosed based on ECG findings and/or any medical history of AF from referring physicians. The crude and independent association between SUA levels and AF prevalence was evaluated with logistic regression analysis.

RESULTS

AF prevalence was 0.6% (53/8937). Participants with hyperuricaemia had a higher AF prevalence compared with those with normal SUA levels (1.1% vs 0.5%; P=0.02). Hyperuricaemia was correlated with AF after adjustment for various cardiovascular risk factors in all participants (P=0.03, OR 2.051, 95% CI 1.063 to 3.856). This correlation was particularly stronger in women compared with men (P<0.001, OR 6.366, 95% CI 2.553 to 15.871 in women and P=0.96, OR 1.025, 95% CI 0.400 to 2.626 in men).

CONCLUSIONS

We demonstrated a significant association between increased SUA levels and AF prevalence in a Chinese population. Our data indicate that there is a gender-specific mechanism underlying the relationship between SUA and AF.

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 Excretion Predicts Increased Blood Pressure Among American Adolescents of African Descent

BACKGROUND

Hyperuricemia predicts the incidence of hypertension in adults and its treatment has blood pressure (BP)-lowering effects in adolescents. To date, no studies have examined the predictive usage of hyperuricemia or urinary uric acid excretion on BP changes in adolescents. Mechanistic models suggest that uric acid impairs both endothelial function and vascular compliance, which would potentially exacerbate a myriad of hypertensive mechanisms, yet little is known about interaction of uric acid and other hypertension risk factors.

MATERIALS AND METHODS

The primary study was aimed at the effects of stress on BP in adolescents. A community sample of 84 low-income, urban adolescents (50% male, 95% African American, mean age = 13.36 ± 1 years) was recruited from public schools. Youth completed a 12-hour (overnight) urine collection at home and their BP was measured during rest and in response to acute psychosocial stress. Seventy-six of the adolescents participated in a follow-up visit at 1.5 years when their resting BP was reassessed. In this substudy, we assessed the relationship of renal urate excretion and BP reactivity.

RESULTS

After adjusting for resting BP levels at baseline and other covariates, higher levels of uric acid excretion predicted greater BP reactivity to acute psychosocial stress and higher resting BP at 18 months.

CONCLUSIONS

Urinary excretion of uric acid can serve as an alternative, noninvasive measure of serum uric acid levels that are predictive of BP changes. As hyperuricemia-associated hypertension is treatable, urban adolescents may benefit from routine screening for hyperuricemia or high uric acid excretion.

Effect of uric acid-lowering therapy on blood pressure: systematic review and meta-analysis

BACKGROUND

The purpose of this meta-analysis was to determine if uric acid-lowering therapy is associated with a decrease in blood pressure (BP) and serum creatinine levels.

MATERIALS AND METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 29 June 2016, with keywords: uric-acid-lowering therapy, allopurinol, febuxostat, uricosuric, and BP. Only randomized controlled trials were included. The primary outcomes were reduction in systolic BP (SBP) and diastolic BP (DBP), and secondary was reduction in serum creatinine level.

RESULTS

Patients treated with allopurinol had greater reduction in SBP (standardized difference in means [SDM] = 0.321, 95% confidence interval [CI]: 0.145-0.497, p < 0.001), DBP (SDM = 0.260, 95% CI: 0.102 to 0.417, p = 0.001), and creatinine level (SDM = 0.312, 95% CI: 0.008 to 0.615, p = 0.044) than control patients. Subgroup analysis showed that allopurinol significantly decreased SBP whether or not antihypertensive drugs were being administered; a decrease in DBP was only seen in patients receiving antihypertensive drugs. Low-dose allopurinol (≤300 mg/day) was more effective at reducing SBP than high-dose (>300 mg/day) in patients receiving antihypertensive drugs.

CONCLUSIONS

These results support that allopurinol decreases BP and creatinine levels in patients with hyperuricemia. KEY MESSAGES Allopurinol decreases SBP and DPB, and creatinine levels in patients with hyperuricemia. Allopurinol resulted in a significant decrease in SBP in patients with or without treatment of antihypertensive drugs. A dose of allopurinol of ≤300 mg per day might be more effective than a higher dose.

High salt intake does not aggravate glucose dysregulation and dyslipidemia induced by estrogen-progestin oral contraceptive

BACKGROUND

Estrogen-progestogen combined oral contraceptive (OC) use has been associated with increased cardiometabolic risk factors, including glucose dysregulation, dyslipidemia, hypertension, and pro-inflammatory state. However, the effect of a high-salt diet on these risk factors during OC use is not yet investigated. We therefore hypothesized that a high-salt diet would increase cardiometabolic risk factors in female rats treated with a combination of OC steroids, levonorgestrel (L) and ethinylestradiol (EE), and that elevated plasma levels of pro-inflammatory markers are associated with the cardiometabolic effects.

METHODS

Female Wistar rats were given (p.o.) vehicle, high-dose (1.0μg EE plus 5.0μgL) or low-dose (0.1μg EE plus 0.5μgL) OC with or without a high-salt diet (8%) daily for 8 weeks. Insulin resistance (IR) was estimated using the homeostatic model of assessment (HOMA).

RESULTS

Results showed that OC treatment or high salt diet led to significant increases in insulin resistance, plasma insulin, total cholesterol (TC), triglyceride (TG), TC/HDL-cholesterol, uric acid levels, and decreased glucose tolerance. OC treatment but not a high-salt diet resulted in increased plasma C-reactive protein and TG/HDL-cholesterol. However, a high-salt diet did not aggravate the effects of OC treatment.

CONCLUSION

The results from the present study indicate that glucose dysfunction and dyslipidemia induced by OC use, but not those induced by increased dietary salt are associated with elevated plasma C-reactive protein. Besides, increased dietary salt does not worsen abnormal cardiometabolic impact of OC use.

Serum uric acid levels are associated with obesity but not cardio-cerebrovascular events in Chinese inpatients with type 2 diabetes

We aim to explore the associations between serum uric acid (SUA) and obesity and cardio-cerebrovascular events (CCEs) in Chinese inpatients with type 2 diabetes mellitus (T2DM). 2 962 inpatients with T2DM were stratified into quartile based on SUA concentrations. There were significant increases in the prevalence of both obesity (32.6%, 41.9%, 50.1%, and 62.8%, respectively, p < 0.001 for trend) and severe obesity (0.4%, 0.6%, 0.8%, and 1.3%, respectively, p < 0.001 for trend) across the SUA quartiles. A fully adjusted multiple logistic regression analysis revealed that SUA quartiles were independently associated with the presence of obesity (p < 0.001). The prevalence of CCEs was significantly higher in the obese diabetics than in the nonobese diabetics (16.8% vs. 13.2%, p = 0.027). After controlling for multiple confounding factors, BMI levels were also significantly correlated with the presence of CCEs (p = 0.020). However, there was no significant association of SUA quartiles/SUA levels with the presence of CCEs in T2DM. This study suggested that SUA levels were independently associated with obesity but not with CCEs in patients with T2DM. In selected populations such as subjects with T2DM, the role of uric acid in cardiovascular complications might be attributable to other cardiovascular risk factors, such as obesity.

Sex-specific Association Between Uric Acid and Outcomes After Acute Ischemic Stroke: A Prospective Study from CATIS Trial

The relationship between serum uric acid (UA) and outcomes after acute ischemic stroke remains debatable in human studies, and the sex effect on this association has yet to be explored. Here, we investigated these associations in a prospective study from the China Antihypertensive Trial in Acute Ischemic Stroke. Baseline UA levels were measured in 3284 acute ischemic stroke patients. Primary outcome was defined as a combination of death and major disability (modified Rankin Scale score ≥3) at 3 months. UA levels were significantly higher in men than women (310.6 ± 96.1 vs 257.5 ± 89.9 μmol/L, P < 0.001). The association between serum UA and the primary outcome was appreciably modified by sex (P-interaction = 0.007). After multivariate adjustment, a high serum UA was associated with a decreased risk of primary outcome in men [odds ratio (OR), 0.63; 95% confidence interval (CI), 0.44-0.91; P-trend = 0.01] but not in women (OR, 1.29; 95% CI, 0.83-2.01; P-trend = 0.15), when two extreme quartiles were compared. Subgroup and sensitivity analyses further confirmed these sex-specific findings. Our study indicated that there was a sex-specific association between serum UA and prognosis of acute ischemic stroke. Elevated serum UA was positively associated with better prognosis in men, but not in women.

Serum uric acid is an independent predictor for developing prehypertension: a population-based prospective cohort study

Although the prevalence of prehypertension is rapidly increasing in China, the medical community has paid little attention to its prevention. Prior studies have demonstrated that uric acid directly contributes to vascular remodelling and endothelial dysfunction. However, few prospective studies have assessed the relationship between serum uric acid and prehypertension. We therefore designed a larger-scale cohort study to examine whether uric acid level is a predictive factor for developing prehypertension in adults. Participants were recruited from Tianjin Medical University General Hospital-Health Management Centre. A prospective assessment (n=15 143) was performed. Participants without a history of hypertension or prehypertension were followed up for 2 to 6 years with a median follow-up duration of 2.8 years. Serum uric acid levels and blood pressure were assessed yearly during the follow-up. Adjusted Cox proportional hazards regression models were used to assess relationships between the quintiles of uric acid levels and the incidence of prehypertension. The incidence of prehypertension was 191 per 1000 person-years. In the final multivariate models, the hazard ratios (95% confidence interval) for prehypertension across uric acid quintiles were 1.00 (reference), 0.98 (0.90-1.07), 1.01 (0.93-1.10), 1.09 (1.001-1.20) and 1.17 (1.06-1.29) (P for trend <0.001), respectively. This population-based prospective cohort study has demonstrated that uric acid level is an independent predictor for developing prehypertension.

Hyperuricemia and uncontrolled hypertension in treated hypertensive patients: K-MetS Study

Previous epidemiological studies have suggested that uric acid is an independent risk factor for incident hypertension, whereas few studies have evaluated the effect of hyperuricemia on blood pressure control in hypertensive patients. We investigated whether hyperuricemia predicts uncontrolled hypertension through a large-scale prospective cohort study with hypertensive patients treated with fimasartan in the Republic of Korea (the Kanarb-Metabolic Syndrome study).Of the 10,601 hypertensive patients who were recruited from 582 private clinics and 11 university hospitals at baseline, 7725 completed the follow-up after 3 months of fimasartan medication, and 6506 were included in the analysis after excluding those with missing values. We estimated the risk of uncontrolled hypertension after 3 months (≥130/80 mm Hg in those with diabetes or chronic renal failure and ≥140/90 mm Hg in the remaining patients) related with baseline hyperuricemia (serum uric acid ≥7 mg/dL in males ≥6 mg/dL in females) using multiple logistic regression models.Hyperuricemia increased the risk of uncontrolled hypertension after 3 months of fimasartan medication (odds ratio, 1.247; 95% confidence interval, 1.063-1.462). Males in the highest quartile of uric acid level were at a 1.322 (95% confidence interval, 1.053-1.660) times higher risk of uncontrolled hypertension in reference to the lowest quartile; the same analyses in females were not significant. Patients without metabolic syndrome had significantly higher odds of uncontrolled hypertension with hyperuricemia (odds ratio, 1.328; 95% confidence interval, 1.007-1.751).Hyperuricemia predicted uncontrolled hypertension even after 3 months of fimasartan treatment in hypertensive patients.

Associations between serum uric acid and the incidence of hypertension: a Chinese senior dynamic cohort study

Background

The prevalence of hyperuricemia has increased dramatically during the past several decades. Studies indicating uric acid is an independent risk factor for hypertension did not sufficiently control for other known risk factors. We explored this relationship in a comprehensive Chinese senior dynamic cohort.

Methods

To investigate the relationship between serum uric acid (SUA) levels and hypertension, we carried out a 6-year retrospective study (2006–2011) in a dynamic cohort with 3591 subjects free of hypertension. The first occasion of documented hypertension per subject was the index event. A Cox proportional hazards model assessed the relationship between SUA and hypertension. Kaplan–Meier survival analysis compared incidence of hypertension among individuals with each SUA quartile. Receiver operating characteristic curves were generated to obtain the area under the curve as a prediction of hypertension from SUA levels.

Results

The cumulative prevalence of hypertension in our cohort was 20.7 %. The prevalence of hyperuricemia was 17.5 %. Cox regression analysis showed that, compared with the lowest SUA quartile (<4.69 mg/dl), the 4.69–5.58, 5.58–6.52, and ≥6.52 mg/dl quartiles yielded hazard ratios (95 % confidence intervals) for hypertension of 1.652 (1.265–2.156), 2.195 (1.705–2.825), and 3.058 (2.399–3.899), respectively. Cumulative incidence of hypertension was consistently higher among individuals with hyperuricemia than among those with normal SUA levels. A Kaplan–Meier survival analysis showed that hyperuricemia predicted higher incidences of hypertension in a dose-dependent manner: hypertension onset significantly differed across SUA quartiles. SUA levels were significantly and independently associated with incidence of hypertension in our cohort.

Conclusions

Our results, controlling for known risk factors, suggest that SUA level is an independent risk factor for hypertension and could be a useful indicator of hypertension.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-016-0866-0) contains supplementary material, which is available to authorized users.

Serum uric acid and the risk of cardiovascular and renal disease

Substantial evidence suggests that chronic hyperuricemia is an independent risk factor for hypertension, metabolic syndrome, chronic kidney disease (CKD) and cardiovascular diseases. This highlights the need for greater attention to serum uric acid levels when profiling patients, and suggests that the threshold above which uricemia is considered abnormal is 6  mg/dl, in light of the available evidence. Another important question is whether lowering serum uric acid can improve cardiovascular and renal outcomes, and what therapeutic mechanism of action could provide more clinical benefits to patients; the available literature shows a trend toward improvement associated with administration of urate-lowering drugs, in particular for the xanthine oxidase inhibitors. The demonstrated efficacy of urate-lowering therapy on outcomes other than gout flares leads to the consideration that treatment may be beneficial even in the absence of overt gout when hyperuricemia accompanies other clinical conditions, such as urate deposition, advanced CKD or cardiovascular risk factors.

Influence of Salt Intake on Association of Blood Uric Acid with Hypertension and Related Cardiovascular Risk

Background

A relationship of blood uric acid (UA) with hypertension and cardiovascular risk is under debate thus salt intake is hypothesized to contribute to such associations.

Methods

In this cross-sectional study, stratified cluster random sampling elicited a sample of 1805 Kazakhs with 92.4% compliance. Hypertension and moderate-or-high total cardiovascular risk (mTCR) were defined according to guidelines. Sodium intake was assessed by urinary sodium excretion. Prevalence ratios (PRs) were used to express associations of UA with hypertension and mTCR.

Results

In the highest tertile of sodium intake in women, the adjusted PRs (95% confidence intervals) of low to high quartiles compared with the lowest quartile of UA, were 1.22(0.78–1.91), 1.18(0.75–1.85), and 1.65(1.09–2.51) for hypertension and 1.19(0.74–1.90), 1.39(0.91–2.11), and 1.65(1.10–2.47) for mTCR (P for trend <0.05). However, these findings were not shown for other sodium intake levels. There were similar results in men. PRs markedly increased with a concomitant increase in UA and sodium intake and there was a significant interaction (P = 0.010) for mTCR with PRs of 1.69(1.10–2.60) for men and 3.70(2.09–6.52) for women in those with the highest compared with the lowest quartile of UA and tertile of sodium intake. Similar findings were shown for hypertension.

Conclusions

This study implied that a high salt intake may enhance the associations of UA with hypertension and cardiovascular risk.

Disparities in Hypertension Prevalence, Awareness, Treatment and Control between Bouyei and Han: Results from a Bi-Ethnic Health Survey in Developing Regions from South China

Hypertension is highly prevalent in low-income population. This study aims to investigate ethnic disparities in hypertension and identify modifiable factors related to its occurrence and control in developing regions in South China. Blood pressure was measured in the Bouyei and Han populations during a community-based health survey in Guizhou, 2012. A multistage stratified sampling method was adopted to recruit Bouyei and Han aged from 20 to 80 years. Taking mixed effects into consideration, multilevel logistic models with random intercept were used for data analysis. The prevalence rates of hypertension were 35.3% for the Bouyei and 33.7% for the Han. Among the hypertensive participants, 30.1% of the Bouyei and 40.2% of the Han were aware of their hypertensive conditions, 19.7% of the Bouyei and 31.1% of the Han were receiving treatment, and only 3.6% of the Bouyei and 9.9% of the Han had their blood pressure under control. Age-sex standardized rates of awareness, treatment, and control were consistently lower in the Bouyei than the Han. Such ethnic disparities were more evident in the elderly population. Avoidance of excessive alcohol consumption and better education were favorable lifestyle for reduction in risk of hypertension. Moderate physical activity improved control of hypertension in Bouyei patients under treatment. Conclusively, hypertension awareness, treatment, and control were substantially lower in Bouyei than Han, particularly in the elderly population. Such ethnic disparities indicate that elderly Bouyei population should be targeted for tailored interventions in the future.

Qingdao Port Cardiovascular Health Study: a prospective cohort study

PURPOSE

In China, efforts are underway to respond to rapidly increasing rates of heart disease and stroke. Yet the epidemiology of cardiovascular disease in China may be different from that of other populations. Thus, there is a critical need for population-based studies that provide insight into the risk factors, incidence and outcomes of cardiovascular disease in China. The Qingdao Port Cardiovascular Health Study is designed to investigate the burden of cardiovascular disease and the sociodemographic, biological, environmental and clinical risk factors associated with disease onset and outcomes.

PARTICIPANTS

For this study, from 2000 through 2013, 32,404 employees aged 18 years or older were recruited from the Qingdao Port Group in China, contributing 221,923 annual health assessments. The mean age at recruitment was 43.4 (SD=12.9); 79% were male. In this ongoing study, annual health assessments, governed by extensive quality control mechanisms, include a questionnaire (capturing demographic and employment information, medical history, medication use, health behaviours and health outcomes), physical examination, ECG, and blood and urine analysis. Additional non-annual assessments include an X-ray, echocardiogram and carotid ultrasound; bio-samples will be collected for future genetic and proteomic analyses. Cardiovascular outcomes are accessed via self-report and are actively being verified with medical insurance claims; efforts are underway to adjudicate outcomes with hospital medical records.

FINDINGS TO DATE

Early findings reveal a significant increase in cardiovascular risk factors from 2000 to 2010 (hypertension: 26.4-39.4%; diabetes: 3.3-8.9%; hyperlipidaemia: 5.0-33.6%; body mass index >28 m/kg(2): 14.1-18.6%).

FUTURE PLANS

We aim to generate novel insights about the epidemiology and outcomes of cardiovascular disease in China, with specific emphasis on the potentially unique risk factor profiles of this Chinese population. Knowledge generated will be disseminated in the peer-reviewed literature, and will inform population-based strategies to improve cardiovascular health in China.

TRIAL REGISTRATION NUMBER

NCT02329886.

Bidirectional Association between Self-Reported Hypertension and Gout: The Singapore Chinese Health Study

It has been hypothesized that the association between hypertension and gout is bidirectional, however, few studies have examined this in a prospective cohort. We analyzed data from the Singapore Chinese Health Study (SCHS) follow-up I (1999–2004) and II (2006–2010) interviews, when both physician-diagnosed hypertension and gout were self-reported. We included participants with data for both follow-up interviews and who were free of heart disease, stroke and cancer at follow-up I. The analysis of hypertension and risk of gout included 31,137 participants when prevalent gout cases were excluded, while the analysis of gout and risk of hypertension included 20,369 participants when prevalent hypertension cases were excluded. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). The mean age at follow-up I was 60.1 (SD 7.3) years, and the average follow-up was 6.8 (SD 1.4) years. In the analysis of hypertension and risk of gout, 682 incident cases were identified. Compared to normotensive participants, hypertensive patients had an88% increased risk of developing gout (HR 1.88; 95% CI 1.61–2.21). In the parallel analysis, 5,450 participants reported to have newly diagnosed hypertension during follow-up. Compared to participants without gout, those with gout had an18% increased risk of developing hypertension (HR 1.18; 95% CI 1.02–1.37). The bidirectional association was stronger in normal weight adults compared to overweight/obese individuals (P_interaction = 0.06 and 0.04, respectively). The hypertension to gout association was stronger in women compared to men (P_interaction = 0.04), while the gout to hypertension association was evident in women but not in men (P_interaction = 0.02). In conclusion, our results suggest that the hypertension-gout association is bidirectional in this cohort of Singapore Chinese adults. The potential interactions of the bidirectional association with obesity and sex deserve further investigations.

Potential causal associations between vitamin D and uric acid: Bidirectional mediation analysis

Vitamin D deficiency, a major public-health worldwide, is associated with hyperuricemia but casual association is questioned. The study was conducted to determine potential causal associations between 25-hydroxy vitamin D (25(OH)D) and uric acid (UA). A cross-sectional study of the Electricity Generating Authority of Thailand (EGAT3) cohort was conducted. Subjects (n = 2,288) were used to genotype the group-specific component (GC) at rs2282679 and ATP-binding cassette subfamily G member 2 (ABCG2) at rs2231142. Mediation analysis with 1000-replication bootstrap was applied to construct causal pathways i.e., rs2282679 → 25(OH)D → UA and rs2231142 → UA → 25(OH)D: The mediator (i.e., 25(OH)D and UA) was firstly regressed on the studied gene (i.e., rs2282679 and rs2231142). A potential causal effect of C allele on UA through 25(OH)D was -0.0236 (95% CI: -0.0411, -0.0058), indicating every minor C allele resulted in decreasing the 25(OH)D and then significantly decreased the UA by 0.0236 unit. For the second pathway, the mediation effect was 0.0806 (95% CI: 0.0107, 0.1628); every T allele copy for rs2231142 increased UA and thus increased 25(OH)D by 0.0806 unit. Our study suggested potential causal associations between the GC gene and UA through the 25(OH)D mediator, and the ABCG2 and the 25(OH)D through the UA mediator but the absolute effects are very clinically small.

Gender differences in the association between serum uric acid and prognosis in patients with acute coronary syndrome

BACKGROUND

Increased levels of uric acid (UA) have been associated with cardiovascular disease. This association is generally stronger in women than men. However, gender differences in the prognostic value of UA in patients with acute coronary syndrome (ACS) are unknown. We investigated gender differences in the relationship between UA level and the prognosis in patients with ACS.

METHOD

This was an observational analysis of patients with ACS undergoing percutaneous coronary intervention enrolled in the Ibaraki Cardiac Assessment Study (ICAS) registry. We analyzed 1380 patients (330 women, 1050 men) with ACS who had information on UA. We assessed the association between UA and the incidence of major cardiovascular adverse events (MACE), defined as all-cause death, congestive heart failure, reinfarction, and stroke. Patients were divided according to gender-specific UA quartile.

RESULTS

The mean UA level in women was significantly lower than that in men (4.9mg/dl vs 5.9mg/dl, p<0.001). After a median duration of follow-up period of 437 days (interquartile range 222-801 days), MACE had occurred in 186 (13%) patients [56 (17%) events in women; 130 (12%) events in men]. Kaplan-Meier analysis for MACE-free survival demonstrated that a higher quartile of UA was associated with MACE in both women and men (p<0.001, p=0.002, respectively). Multivariate Cox regression analysis revealed that the highest quartile of UA, as compared with the lowest quartile of UA, was an independent predictor of MACE in women [hazard ratio (HR), 2.84; 95% CI, 1.19-6.77; p=0.018] but not in men (HR, 1.32; 95% CI, 0.66-2.64; p=0.422).

CONCLUSIONS

An increased level of UA was associated with MACE more strongly in women than in men with ACS. These results suggest that there are gender differences in the association of UA level with the prognosis in patients with ACS.

Serum uric acid and the incidence of CKD and hypertension

Background

Uric acid (UA) levels correlate positively with the prevalence of chronic kidney disease (CKD) and/or hypertension. We tested the hypothesis that UA may also have a link to a new incidence of CKD and hypertension.

Methods

Study design is a cohort study and the predictor is UA levels. Of the 15,470 screened cases, 8223 participants without CKD were eligible for the analysis of the incidence of CKD. Among these CKD candidates, 7569 participants were eligible for the analysis of the new development of hypertension. The observation period was 4 years.

Results

Relationship of UA with new cases of CKD. Higher UA levels had a closer association with the new development of CKD; 1.1 % (UA < 5 mg/dL), 1.5 % (5.0–5.9 mg/dL), 1.7 % (6.0–6.9 mg/dL), and 3.4 % (≧7 mg/dL), respectively (p < 0.001 by the Chi-square test). Cox proportional hazard analysis showed that the estimates of the CKD development were eGFR [Hazard Ratio (HR) 0.816, 95 % confidence intervals (CI) 0.791–0.840] and male gender (HR 0.562, 95 % CI 0.322–0.982). UA levels and new development of hypertension. Higher UA levels had a closer association with the new development of hypertension; 5.0 % (UA < 5 mg/dL), 8.9 % (5.0–5.9 mg/dL), 10.6 % (6.0–6.9 mg/dL), and 11.8 % (≧7 mg/dL), respectively (p < 0.001 by the Chi-square test). Cox proportional hazard analysis showed that the estimates of the hypertension development were BMI (HR 1.190, 95 % CI 1.155–1.226), age (HR 1.021, 95 % CI 1.010–1.032), HDL-cholesterol (HR 1.013, 95 % CI 1.007–1.019), male gender (HR 1.791, 95 % CI 1.338–2.395), UA level (HR 1.112, 95 % CI 1.024–1.207), and eGFR (HR 1008, 95 % CI 1.002–1.013). Furthermore, the logistic analysis showed that the odds ratio (OR) to estimate hypertension in the high UA group (UA ≧ 7 mg/dL; OR 1.33, 95 % CI 1.01–1.80) was greater than that in the low UA group (UA < 5 mg/dL). Kaplan–Meier analysis also confirmed the finding that the higher the UA levels the greater the hypertension development (p < 0.001 by the Log-rank test and Cox proportional hazard analysis).

Conclusion

High UA levels are associated with the new development of hypertension, but not with the incidence of CKD.

Plasma Uric Acid as a Prognostic Marker in Patients With Hypertrophic Cardiomyopathy

BACKGROUND

Uric acid (UA) has been shown to be an independent risk factor for various cardiovascular diseases. However, its significance in hypertrophic cardiomyopathy (HCM) has not yet been evaluated. The objective of the present study was to evaluate clinical implications of plasma UA levels on the prognosis of patients with HCM.

METHODS

A total of 588 adult patients with HCM were enrolled at FuWai Hospital from 1999-2011 and followed until 2014. The plasma levels of UA were measured at enrollment.

RESULTS

During the follow-up of 5.2 ± 2.4 years, 44 (7.5%) patients had cardiovascular-related deaths, and 100 (17.0%) patients had cardiac events. Compared with the first tertile of UA concentration (< 284.6 μmol/L), patients in the highest tertile (> 358.7 μmol/L) had a higher risk for the development of adverse events: cardiovascular death (adjusted hazard ratio [HR], 3.10; 95% confidence interval [CI], 1.37-7.04; P = 0.007), all-cause mortality (adjusted HR, 2.33; 95% CI, 1.11-4.89; P = 0.025), cardiac events (adjusted HR, 4.20, 95% CI, 2.38-7.42; P < 0.001), heart failure events (adjusted HR, 3.46; 95% CI, 1.86-6.45; P < 0.001), and arrhythmic events (adjusted HR, 9.19; 95% CI, 2.40-35.25; P = 0.001). Similarly, the continuous variable of UA (for every 1 mg/dL higher concentration) was also an independent predictor for adverse outcomes: cardiovascular death (adjusted HR, 1.29; 95% CI, 1.11-1.49; P = 0.001), all-cause mortality (adjusted HR, 1.23; 95% CI, 1.07-1.41; P = 0.004), cardiac events (adjusted HR, 1.27; 95% CI, 1.15-1.41; P < 0.001), heart failure events (adjusted HR, 1.19; 95% CI, 1.06-1.33; P = 0.003), and arrhythmic events (adjusted HR, 1.60; 95% CI, 1.30-1.98; P < 0.001).

CONCLUSIONS

Our results indicate that UA is an independent predictor of adverse outcomes in patients with HCM.

Reconstruction and analysis of correlation networks based on GC-MS metabolomics data for young hypertensive men

The awareness, treatment, and control rates of hypertension for young adults are much lower than average. It is urgently needed to explore the variances of metabolic profiles for early diagnosis and treatment of hypertension. In current study, we applied a GC-MS based metabolomics platform coupled with a network approach to analyze plasma samples from young hypertensive men and age-matched healthy controls. Our findings confirmed distinct metabolic footprints of young hypertensive men. The significantly altered metabolites between two groups were enriched for the biological module of amino acids biosynthesis. The correlations of GC-MS metabolomics data were then visualized as networks based on Pearson correlation coefficient (threshold=0.6). The plasma metabolites identified by GC-MS and the significantly altered metabolites (P<0.05) between patients and controls were respectively included as nodes of a network. Statistical and topological characteristics of the networks were studied in detail. A few amino acids, glycine, lysine, and cystine, were screened as hub metabolites with higher values of degree (k), and also obtained highest scores of three centrality indices. The short average path lengths and high clustering coefficients of the networks revealed a small-world property, indicating that variances of these amino acids have a major impact on the metabolic change in young hypertensive men. These results suggested that disorders of amino acid metabolism might play an important role in predisposing young men to developing hypertension. The combination of metabolomics and network methods would provide another perspective on expounding the molecular mechanism underlying complex diseases.

Hyperuricemia and risk of incident hypertension: a systematic review and meta-analysis of observational studies

Background

Observational studies of the relationship between hyperuricemia and the incidence of hypertension are controversial. We conducted a systematic review and meta-analysis to assess the association and consistency between uric acid levels and the risk of hypertension development.

Methods

We searched MEDLINE, EMBASE, CBM (Chinese Biomedicine Database) through September 2013 and reference lists of retrieved studies to identify cohort studies and nested case-control studies with uric acid levels as exposure and incident hypertension as outcome variables. Two reviewers independently extracted data and assessed study quality using Newcastle-Ottawa Scale. Extracted information included study design, population, definition of hyperuricemia and hypertension, number of incident hypertension, effect sizes, and adjusted confounders. Pooled relative risks (RRs) and corresponding 95% confidence intervals (CIs) for the association between hyperuricemia and risk of hypertension were calculated using a random-effects model.

Results

We included 25 studies with 97,824 participants assessing the association between uric acid and incident hypertension in our meta-analysis. The quality of included studies is moderate to high. Random-effects meta-analysis showed that hyperuricemia was associated with a higher risk of incident hypertension, regardless of whether the effect size was adjusted or not, whether the data were categorical or continuous as 1 SD/1 mg/dl increase in uric acid level (unadjusted: RR = 1.73, 95% CI 1.46∼2.06 for categorical data, RR = 1.22, 95% CI 1.03∼1.45 for a 1 SD increase; adjusted: RR = 1.48, 95% CI 1.33∼1.65 for categorical data, RR = 1.15, 95% CI 1.06∼1.26 for a 1 mg/dl increase), and the risk is consistent in subgroup analyses and have a dose-response relationship.

Conclusions

Hyperuricemia may modestly increase the risk of hypertension incidence, consistent with a dose-response relationship.

Serum uric acid and the risk of hypertension and chronic kidney disease

PURPOSE OF REVIEW

To discuss the evolving data regarding uric acid as a potential cause of hypertension and progressive renal dysfunction and its clinical and research implications.

RECENT FINDINGS

The potential mechanisms by which uric acid could cause vasoconstriction and a progressive ateriolopathy were established in animal models between 1999 and 2004. Since then, there has been a growing interest in the topic and numerous retrospective and prospective observational studies. The preponderance of data support the hypothesis that serum uric acid is a cause or exacerbating factor of hypertension and progressive kidney disease. Over the last couple of years clinical intervention trials, including randomized controlled trials in the young have supported this mechanistic role.

SUMMARY

Current evidence supports the role of uric acid as marker and mediator of risk for both hypertension and progressive decline in renal function. Data on the impact of xanthine oxidase inhibitors or uricosurics on clinical hypertension and chronic kidney disease are suggestive but inconclusive. Considerably, more data will be required to determine if uric acid lowering therapy will become a mainstay of management in diseases other than gout and tumor lysis syndrome.