Age-differential association between serum uric acid and incident hypertension

Contribution of Food, Energy, Macronutrients and Fiber Consumption Patterns to Obesity and Other Non-Communicable Disease Risks in the Indonesian Population

BACKGROUND

Obesity, characterized by excess body fat, has been recognized as one of the main global health problems of the current times. This article, based on the data from the Cohort study of risk factors for non-communicable diseases in Indonesia (FRPTM), aims to analyze the food consumption patterns and their association with the risk of obesity and related non-communicable diseases (NCDs) in the Indonesian population.

METHODS

The article presents data collected from 867 respondents aged 25 years and above observed for 5 years: 2011, 2013, 2015, 2017 and 2019. It includes sociodemographic characteristics, consumption (1 × 24-h recall), anthropometry, and biomedical data (lipid profile, blood glucose, blood pressure).

RESULTS

The study identified cereals as the food group consumed in the largest amount and the largest contributor to energy, protein, carbohydrates and fiber intake. The fats and oils group exceeded the recommended intake, while vegetable and fruit consumption, and consequently the fiber intake, were far below the recommendations. The energy and macronutrient intake, and the percentage of respondents with excessive intake levels, were consequently increasing during the studied years. The consumption patterns were associated with the incidence of obesity, which increased from 43.9% in 2011 to 69.9% (central obesity) and 67.9% (BMI-based obesity) in 2019.

CONCLUSIONS

The dynamics of the consumption patterns clearly impacted the obesity prevalence. At the same time, the NCDs biomarkers measured remained relatively stable despite increasing obesity and macronutrient intake over the study period. The study provides important insights into diet-related risks for obesity in Indonesia, with a potential to inform public health policies and relevant intervention strategies.

Association of uric acid to high-density lipoprotein cholesterol ratio with the presence or absence of hypertensive kidney function: results from the China Health and Retirement Longitudinal Study (CHARLS)

OBJECTIVE

Some studies have shown that uric acid (UA) to high-density lipoprotein (HDL-C) ratio (UHR), as an indicator of inflammation, is associated with metabolic syndrome and hypertension, but its relationship with decreased renal function is unclear. This study intends to analyze the relationship between UHR and decline in renal function.

METHODS

Data were obtained from the 2011-2015 data of the China Health and Aging Tracking Survey (CHARLS) of Peking University, and 7,198 study participants were included and followed up until 2015. The eGFR (Total glomerular filtration rate) was estimated according to the CKD-EPI [1] creatinine equation. eGFR ≥ 60mL/min/1.73 m² at baseline renal function was defined as normal renal function, and eGFR < 60mL/min/1.73 m² at baseline renal function was defined as chronic kidney disease; new-onset eGFR < 60mL/min/1.73 m² was defined as the occurrence of decline in renal function; in the chronic kidney disease population decrease in eGFR ≥ 5mL/min/1.73 m²/year or 30% from baseline or admission to dialysis was defined as rapid progression of chronic kidney disease. eGFR slope was defined as the ratio of the difference between the final eGFR and the baseline eGFR over 4 years of follow-up. Binary logistic regression was used to analyze the relationship between UHR and renal function decline or progression, as well as linear regression and non-linear regression to clarify the relationship between UHR and GFR slope in hypertensive patients, and the correlation between UHR and CRP, and to assess the relationship between UHR levels and the risk of renal function decline in hypertensive people.

RESULTS

(1) Hypertension was a risk factor for the decline of renal function (OR: 1.34, P = 0.03); (2) UHR was a risk factor for the decline of renal function in the hypertensive population (OR: 1.32, P = 0.02), and with the increasing level of UHR, the risk of developing CKD (Chronic Kidney Disease) in hypertension was higher (P for trend = 0.03); (3) The subgroup analyses showed that there was no interaction between hypertension and age, cystatin C and hemoglobin did not interact with each other; (4), In the hypertensive population, the slope of UHR and eGFR showed a J-shaped correlation, with UHR > 7.6% as the cut-off point, and the slope of eGFR tended to increase with increasing UHR; in the non-hypertensive population UHR and eGFR showed a linear correlation, and the slope of the decline in eGFR was smaller than that of the hypertensive population; (5), After adjusting for confounders, UHR and CRP were positive correlation (t = 3.56, P < 0.05); (6) In the hypertensive population with normal CRP, the risk of decline in renal function increased accordingly with increasing UHR (P = 0.003). UHR did not show a correlation with CRP in the hypertensive population with abnormal CRP (P = 0.24).

CONCLUSION

In the hypertensive population, elevated UHR is associated with an increased risk of decline in renal function; with UHR > 7.6% as the cut-off point, the slope of eGFR tended to increase with increasing UHR, and UHR can be used as an indicator for risk stratification of renal injury in the hypertensive population.

High serum uric acid/creatinine ratio is a useful predictor of hypertension among Japanese community-dwelling persons

Background

The correlation between serum uric acid/creatinine (SUA/Cr) ratio and hypertension risk has not been well studied. This study aims to examine whether the SUA/Cr ratio is a predictor of hypertension.

Methods

This cohort study comprised 171 men aged 64 ± 11 (mean ± standard deviation) years and 266 women aged 65 ± 10 years recruited for a survey at the community-based annual medical check-up. The main outcome was the presence of hypertension (antihypertensive medication) and having systolic blood pressure (SBP) ≥ 140 mmHg and diastolic blood pressure (DBP) ≥ 90 mmHg.

Results

The baseline SUA/Cr ratio was significantly correlated only with DBP at 3 years in men (r = 0.217, P = 0.004) and women (r = 0.126, P = 0.040), and with both SBP (r = 0.103, P = 0.031) and DBP (r = 0.15, P = 0.001) in the overall participants of men and women. A plausible prognostic cut-off of SUA/Cr ratio (≥ 7.41) was found and was the same in women and in all participants. Multivariable logistic regressions showed that SUA/Cr ratio was significantly linked with hypertension (as a categorical variable, SUA/Cr ratio-2 vs. SUA/Cr ratio-1: odds ratio [OR], 1.68; 95% confidence interval [CI], 0.66-4.30; P = 0.275, SUA/Cr ratio-3 vs. SUA/Cr ratio-1: OR, 2.86; 95% CI, 1.08-7.60; P = 0.035, SUA/Cr ratio-4 vs. SUA/Cr ratio ratio-1: OR, 4.05; 95% CI, 1.32-12.5; P = 0.031, and SUA/Cr ratio ≥ 7.41 vs. SUA/Cr ratio < 7.41: OR, 2.25; 95% CI, 1.32-3.84; P = 0.003). Significant ORs were found for age < 65 years, women, and BMI <25 kg/m2, but no interactions were identified within each group.

Conclusions

These results suggest that the baseline SUA/Cr ratio could be an important predictor for the incidence of hypertension in Japanese community-dwelling persons.

Serum Albumin and Uric Acid Levels in Hypertensive Patients: A Cross-Sectional Analysis From Central Tamil Nadu, South India

Introduction Hypertension represents a significant global health challenge, with an increasing incidence among adults. Despite the prominence of infectious diseases, non-communicable conditions like hypertension remain a silent yet critical health concern. Liver and kidney functions play crucial roles in blood pressure maintenance, with serum albumin and uric acid serving as key metabolic indicators. Objective The primary objective of this study is to analyze the association between serum albumin and uric acid levels in hypertensive patients aged 30-50 years. The secondary objective is to determine whether deranged serum albumin and uric acid levels are associated with other variables like body mass index and blood pressure values. Methods An analytical cross-sectional study was conducted between September and October 2021 at a hospital in Perambalur, Tamil Nadu, India. The study employed non-probability convenient sampling to recruit hypertensive patients aged 30-50 years. Participants with coronary artery disease, stroke, liver disease, renal failure, hyperuricemia, gout, diabetes mellitus, or taking medications that affect albumin or uric acid levels were excluded. Blood pressure measurements were taken after ensuring adequate rest, and 4 ml of venous blood was collected from each participant for biochemical analysis. Serum albumin and uric acid levels were determined using the analyzer. The data analysis was performed using Microsoft Excel and statistical software. The statistical significance of the findings was evaluated using appropriate statistical tests, providing a robust framework for understanding the metabolic associations in hypertension. Results The study population of 150 hypertensive patients demonstrated a majority of 88 (58.67%) aged over 40 years and 62 (41.33%) under 40 years. The gender distribution revealed 87 (58%) males and 63 (42% females). The mean systolic blood pressure was 158.2 mmHg, with a mean diastolic blood pressure of 94.73 mmHg, indicating moderate to severe hypertension. Biochemical analysis showed an average serum uric acid level of 6.41 mg/dL and a mean serum albumin level of 3.54 mg/dL. Statistical analysis revealed a significant association between elevated uric acid levels and decreased serum albumin levels (p < 0.05), suggesting a potential interrelationship between these metabolic markers in hypertensive patients. Conclusion The study establishes hyperuricemia and hypoalbuminemia as significant risk factors for hypertension development or pathogenesis. Early detection of these metabolic derangements may provide opportunities for preventive interventions and potential disease management strategies. The findings emphasize the importance of comprehensive biochemical assessment in understanding and mitigating hypertension risk.

Bibliometric and visual assessment of research trends in the management of hyperuricemia (HUA)

OBJECTIVE

To analyze the development status and trend of related research in the health management of hyperuricemia and provide a theoretical basis for clinical treatment.

METHODS

A bibliometric analysis was conducted on hyperuricemia health management research data from 2000 to 2024 using the Web Science Core Collection database, PubMed, and SINOMED. A total of 789 articles were evaluated for specific characteristics, such as year of publication, journal, author, institution, country/region, reference, and keyword. The VOSviewer was used for co-author, co-occurrence, co-citation, and network visualization. Important sub-topics identified by bibliometric characteristics were discussed and reviewed.

RESULTS

The number of articles published in the last 24 years has generally followed a year-on-year trend, and the total number of papers published is increasing. Over 200 affiliations from 70 countries and regions contributed papers, and PLOS ONE has the highest number of linked publications. Dalbeth N, is the author with the most publications, with an H-index of 17. Hyperuricemia, gout, management, prevalence, allopurinol, risk, and other keywords were often used. Researchers formed mature teams, and the teams' study directions intersect and are comparable. However, these teams demonstrated a lack of communication and coordination.

CONCLUSIONS

This study highlights research hotspots, global cooperation models, and emerging frontiers in hyperuricemia, focusing on uric acid control, disease screening, health education, and epidemiological investigation in hyperuricemia-associated complications over the past two decades. However, there is still a lack of standardized management processes and systems, and the communication between research teams needs to be enhanced. Key Points • The study analyzed hyperuricemia health management research data from 2000 to 2024 using the Web Science Core Collection database, PubMed, and SINOMED, evaluating 789 articles and discussing key sub-topics using VOSviewer. • Over 200 articles from 70 countries, including PLOS ONE, have been published over the past 24 years, focusing on hyperuricemia, gout, management, prevalence, allopurinol risk, etc. • Our study outlines research hotspots, global cooperation models, and emerging hyperuricemia frontiers, emphasizing the need for standardized management processes and improved communication between research teams.

Effects of uric acid on oxidative stress in vascular smooth muscle cells

Hyperuricemia during hypertension is associated with aberrant vascular functions and increased oxidative stress, which affects endothelial dysfunction. Nevertheless, the molecular mechanisms underlying the effects of uric acid on vascular smooth muscle cells (VSMCs) through oxidative stress remain unclear. The aim of the present study was to investigate the dose- and time-dependent effects of uric acid on oxidative stress and p53 protein expression in VSMCs. VSMCs were incubated with various concentrations of uric acid (0-50 mg/dl) for different time periods (1-24 h). Thiobarbituric acid reactive substances (TBARs), protein carbonylation and nitric oxide (NO) levels were determined using appropriate assay kits. Superoxide anion release was detected using the Görlach method. Western blotting was performed to determine the protein expression levels of p53. The findings demonstrated that the application of uric acid led to an increase in protein carbonylation and superoxide anion levels while causing a decrease in NO levels. Conversely, no significant effect was observed on TBARS levels. Additionally, it was observed that high concentrations of uric acid suppressed p53 expression at 6, 12 and 24 h. The present study provided evidence that the influence of uric acid on oxidative stress was more closely associated with time than dose; however, not all effects observed were strictly time-dependent.

The role of uric acid in the risk of hypertension developed from prehypertension: a five-year Chinese urban cohort study

BACKGROUND

Uric acid as a prominent causal factor in the pathogenesis of hypertension is well recognized. Nevertheless, the influence of uric acid on the transition from prehypertension to hypertension within the Chinese population remains understudied.

METHODS

A cohort of 1,516 prehypertensive individuals, aged 35 to 84 years, underwent recruitment following a comprehensive health assessment in 2017 and subsequent re-evaluation in 2022. Baseline characteristics and relevant clinical data were collected. The analytical approach encompassed multiple logistic regression and propensity score matching.

RESULTS

Over 5 years, the cumulative incidence of hypertension amounted to 35.1%, with 33.9% in males and 37.3% in females, respectively. Notably, prehypertensive subjects concomitant with hyperuricemia exhibited a higher cumulative incidence of hypertension in comparison to the non-hyperuricemic counterparts (40.7% vs. 34.0%, p = 0.041). Multiple logistic regression unveiled a significant association between hyperuricemia and heightened hypertension risk (adjusted odds ratio [OR] = 1.44; 95% confidence interval [CI], 1.05-1.98; p = 0.022). Nonetheless, this association did not reach statistical significance when examining female subjects (adjusted OR = 1.10; 95% CI, 0.58-2.09; p = 0.781) or participants aged ≥ 60 years (adjusted OR = 1.07; 95% CI, 0.61-1.88; p = 0.814). Further validation through propensity score matching affirmed that subjects afflicted by hyperuricemia experienced a substantially elevated risk of transitioning from prehypertension to hypertension over the course of five years compared with the non-hyperuricemic counterparts (41.3% vs. 32.3%, p = 0.045), after adjusting for 12 covariates including age and gender. Hyperuricemia emerged as an independent risk factor predisposing individuals to the development of hypertension from a prehypertensive state.

CONCLUSION

This observation prompted the formulation of a hypothesis suggesting that ameliorating elevated uric acid levels may potentially mitigate the progression from prehypertension to hypertension.

Blood Lead Mediates the Relationship between Biological Aging and Hypertension: Based on the NHANES Database

Hypertension remains a major global public health crisis due to various contributing factors, such as age and environmental exposures. This study delves into exploring the intricate association between biological aging, blood lead levels, and hypertension, along with examining the mediating role of blood lead levels in the relationship between biological aging and hypertension. We analyzed data from two cycles of the NHANES, encompassing 4473 individuals aged 18 years and older. Our findings indicate that biological aging potentially escalates the risk of hypertension and the incidences of systolic blood pressure (SBP) and diastolic blood pressure (DBP) abnormalities. Utilizing weighted quantile sum (WQS) and quantile g-computation (QGC) model analyses, we observed that exposure to heavy metal mixtures, particularly lead, may elevate the likelihood of hypertension, SBP, and DBP abnormalities. Further mediation analysis revealed that lead significantly mediated the relationship between biological aging and hypertension and between biological aging and SBP abnormalities, accounting for 64% (95% CI, 49% to 89%) and 64% (95% CI, 44% to 88%) of the effects, respectively. These outcomes emphasize the criticality of implementing environmental health measures.

Hyperuricemia and coronary heart disease: The mediating role of blood pressure and thrombospondin 3

BACKGROUND & AIMS

Although hyperuricemia is a known risk factor for coronary heart disease (CHD), little is known about the role of blood pressure in mediating this association. The purpose of this study is to investigate the role of blood pressure-related indicators and Thrombospondin 3 (THBS3) in the association between hyperuricemia and CHD.

METHODS AND RESULTS

Our observational epidemiology study included 593 CHD cases and 760 controls from a residential stable sample. We also chose 43 new CHD patients and 43 controls to test the expression levels of THBS3 using ELISA kits. We used logistic regression models and mediating effect analysis to investigate the relationships between hyperuricemia and CHD, as well as the mediating role of blood pressure-related indicators and THBS3. In the general population (OR: 2.001 [95% CI: 1.528-2.622]), male population (OR: 1.591 [95% CI: 1.119-2.262]), and female population (OR: 2.813 [95% CI: 1.836-4.310]), hyperuricemia is an independent risk factor for CHD. In general, average systolic blood pressure (SBP) and average pulse pressure difference (PPD) mediated 3.35% and 4.59%, respectively, of the association between hyperuricemia and CHD, and 6.60% and 6.60% in women. However, in the male population, we have not yet found that blood pressure-related indicators had a significant mediating effect. Meanwhile, we found that THBS3 mediated 19.23% of the association between hyperuricemia and CHD.

CONCLUSIONS

Average SBP, PPD, and THBS3 all play a role in the association of hyperuricemia and CHD. In the female population, similar mediating results in blood pressure-related indicators were observed.

Associations of serum uric acid with cardiovascular disease risk factors: a retrospective cohort study in southeastern China

OBJECTIVE

To evaluate the associations between serum uric acid (SUA) levels and cardiovascular disease (CVD) risk factors, focusing on potential sex-specific differences.

DESIGN

A retrospective cohort study.

SETTING

A large community-based survey was conducted every two years from 2010 to 2018 in Hangzhou, Zhejiang Province, outheastern China.

PARTICIPANTS

6119 participants aged 40 years and above who underwent at least three times of physical examinations were enrolled.

METHODS

Participants were categorised into four groups (Q1-Q4) based on baseline SUA quartiles within the normal range, with hyperuricaemia (HUA) as the fifth group. The Q1 was the reference. By stratifying participants by gender, the relationships between SUA levels and systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG) and total cholesterol (TC) were investigated using linear regression models in the generalised estimating equation. Additionally, the associations of elevated SUA levels and HUA with hypertension, hyperglycaemia and dyslipidaemia were correspondingly examined using multivariate logistic regression models.

RESULTS

After adjusting for confounding variables, we found positive associations between SUA levels and SBP, DBP, FBG and TC in women, and with TC in men (p<0.01). Likewise, elevated SUA quartiles and HUA were linked to increased dyslipidaemia risk in both sexes, and increased hyperglycaemia risk only in women, with HRs (95% CI) of 1.64 (1.05 to 2.55) and 2.37 (1.47 to 3.81) in the Q4 and HUA group, respectively. Women with HUA had higher hypertension risk (HR=1.45, 95% CI 1.21 to 1.73), while no such association was observed in men. Stratified analyses revealed significant associations between elevated SUA levels and CVD risk factors in postmenopausal and non-obese women.

CONCLUSIONS

Elevated SUA levels increase the risk of dyslipidaemia in both sexes. SUA levels within normal range and HUA are positively associated with hyperglycaemia and hypertension in postmenopausal women, but not in men.

Relationship between serum uric acid and hypertension in the general US population aged 20 years and older: A cross-sectional study based on NHANES 2007 to 2016

The aim of this study was to investigate the association between serum uric acid (UA) levels and hypertension in American individuals 20 years of age and older. We used continuous cross-sectional surveys from the National Health and Nutrition Examination Survey in the United States from 2007 to 2016. Our selected population was adults aged 20 years and older in the United States. We examined the association between serum UA and risk of hypertension using weighted univariate logistic regression analysis, weighted multivariate logistic regression analysis, weighted subgroup analysis, and weighted restricted cubic spline analysis. Serum UA was significantly linked with hypertension in a multivariate logistic regression model adjusted for all variables (odds ratio [OR]: 1.22, 95% confidence interval [CI]: 1.15-1.28, P < .001). Furthermore, dividing serum UA into quartiles (Q) revealed an association between elevated serum UA and increased risk of hypertension [Q1 = (OR: 1.00), Q2 = (OR: 1.13, 95% CI: 0.95-1.37, P = .159), Q3 = OR: 1.30, 95% CI: 1.10-1.52, P = .002), Q4 = OR: 1.94, 95% CI: 1.58-2.38, P = .161). Additionally, we conducted subgroup analyses for age, sex, race, education, marital status, diabetes status, smoking, and alcohol use and discovered that these factors had a moderating effect on serum UA and hypertension (P < .05). Last but not least, we looked into the nonlinear link between serum UA and hypertension using weighted restricted cubic splines and discovered that there was no such relationship. The segmental effect of serum UA and hypertension, with an inflection point of 5.079 (mg/dL), was discovered in our gender-stratified study. And in analyses stratified by race and marital status, we similarly found a dose-response relationship between UA and hypertension among Hispanics and unmarried people. Our study showed a positive correlation between serum UA and hypertension.

The Ratio of Serum Uric Acid to Glycosylated Haemoglobin as a Predictor of All-Mortality in Elderly Patients with Diabetic Foot Ulcers: A Longitudinal Cohort Study

Aim

To clarify the relationship between serum uric acid (UA) and glycosylated hemoglobin (UA/HbA1c) ratio and all-cause mortality in patients with diabetic foot ulcers (DFUs).

Methods

A total of 172 inpatients with DFUs (PEDIS grades 2-4) were eligible for inclusion in this study from 2018 to 2023. This was a retrospective, longitudinal cohort study. All subjects were followed up every 6 months for a median of 60 months. According to the cutoff value of the UA/HbA1c ratio of 39.07 obtained from ROC analysis, the participants were divided into two groups: low-level (≤ 39.07, n = 107) and high-level (> 39.07, n = 65) groups. The correlation between UA/HbA1c ratio and all-cause mortality was also evaluated by Cox regression analysis TheKaplan-Meier survival curve analysis and Log rank tests were used to assess the incidence rates of all-cause mortality. The contribution rate of risk factors was estimated by the population-attributable risk percentage (PAR%) analysis.

Results

ROC analysis showed that the optimal cutoff values for UA and the UA/HbA1c ratio were 372 μmol/L and 39.07, respectively. Multivariate Cox regression analysis indicated that a high UA/HbA1c ratio (HR =4.63; 95% CI = 2.004-10.7, P < 0.001) was independently associated with a high risk of all-cause mortality in patients with DFUs. Stratified analysis indicated that subjects aged ≥ 60 years had a greater risk of all-cause mortality associated with a high UA/HbA1c ratio (HR = 4.450; 95% CI = 1.711-11.574, P = 0.002). Kaplan-Meier survival analysis showed that all-cause mortality had a significant positive association with a high UA/HbA1c ratio (log-rank, P < 0.001) and a significant negative correlation with the lowered HbA1c level (< 6.5%) after a follow-up of 32 months (log-rank, P < 0.001). The population attributable risk percentage (PAR%) analysis suggested that the contribution rate of the high-level UA/HbA1c ratio to all-cause mortality was 33.7%, which was much greater than the 19.69% of UA.

Conclusion

In brief, our study showed that for every 1.0% increase in the UA/HbA1c ratio, the all-cause mortality rate in elderly patients with DFUs aged ≥ 60 years increased by 3.45-fold. For elderly patients with DFUs, a safe and effective strategy to reduce all-cause mortality is to strictly control serum UA levels to < 372 μmol/L and appropriately loosen the control goal of HbA1c to ≥ 6.5%.

Hyperuricemia is associated with more cardiometabolic risk factors in hypertensive younger Chinese adults than in elderly

Background

Numerous studies have shown that hyperuricemia (HUA) is associated with cardiovascular and renal outcomes, but few studies specifically explored the effect of age on this relationship. Therefore, our study aimed to explore the relationship between HUA and other cardiometabolic risk factors in different age groups.

Methods

This cross-section study used the data from Survey on uric acid in Chinese subjects with essential hypertension (SUCCESS). We performed multivariate logistic regressions in different age groups.

Results

After adjusting for potential confounders, among young and middle-aged adults less than 60, HUA was associated with higher body mass index (BMI, adjusted OR = 1.114, 95% CI: 1.057–1.174), higher fasting blood glucose (FBG, adjusted OR = 1.099, 95% CI: 1.003–1.205), triglycerides (TG, adjusted OR = 1.425, 95% CI: 1.247–1.629), higher low-density lipoprotein cholesterol (LDL-C, adjusted OR = 1.171, 95% CI: 1.025–1.337), and lower estimated glomerular filtration rate (eGFR, adjusted OR = 0.992, 95% CI: 0.988–0.996). Among elderly adults 60 years or older, HUA was associated with higher SBP (adjusted OR = 1.024, 95% CI: 1.005–1.042), higher TG (adjusted OR = 1.716, 95% CI: 1.466–2.009), and higher LDL-C (adjusted OR = 1.595, 95% CI: 1.366–1.863).

Conclusion

HUA is associated with more cardiometabolic risk factors in younger adults with hypertension (HT). Comprehensive management of HT with HUA is needed in clinical settings.

Association Between Uric Acid to HDL Cholesterol Ratio and Diabetic Complications in Men and Postmenopausal Women

AIM

Previous studies have implicated the uric acid to high-density lipoprotein cholesterol (HDL-C) ratio (UHR) was associated with type 2 diabetes. However, the association between UHR and diabetes-related vascular damages is still unclear.

METHODS

The total of 4551 patients with type 2 diabetes from the cross-sectional Environmental Pollutant Exposure and Metabolic Diseases in Shanghai study (METAL study) were enrolled. UHR was calculated as uric acid to HDL-C ratio. Cardiovascular disease (CVD) was defined as previously diagnosed with stroke, coronary heart disease, or peripheral arterial disease. Chronic kidney disease (CKD) was defined as estimated glomerular filtration rate ≤60 mL/min/1.73 m² and/or urinary albumin to creatinine ratio ≥30 mg/g. Fundus image was examined by trained individuals and degree of diabetic retinopathy (DR) was evaluated.

RESULTS

UHR was positively correlated with CVD (OR = 1.28, 95% CI: 1.02-1.61) and CKD (OR = 1.78, 95% CI: 1.39-2.27) after adjusting for all confounders. No association was found between UHR and DR. In stratified analyses, UHR was predominantly correlated with CVD in diabetic patients with age older than 65 (OR = 1.41, 95% CI: 1.08-1.85), female (OR = 1.43, 95% CI: 1.06-1.94) and BMI≥24kg/m² (OR = 1.57, 95% CI: 1.17-2.11). A 1-SD increment of UHR was also positively associated with CVD (OR 1.26, 95% CI 1.03, 1.15) and CKD (OR 1.28, 95% CI 1.20,1.39). UHR was positively associated with CKD in all subgroups analysis. No significant interaction effect was observed between UHR and all subgroup variables in CVD and CKD risk.

CONCLUSION

Our study reported a positive association between the UHR and diabetic-related vascular complications in men and postmenopausal women. The relationship between the UHR and DR seems to be uncertain and requires further investigation. And no significant interaction effect was observed between the UHR and all subgroup variables in CVD and CKD risk.

Comorbidities of nontuberculous mycobacteria infection in Korean adults: results from the National Health Insurance Service–National Sample Cohort (NHIS–NSC) database

Background

The global prevalence and incidence of nontuberculous mycobacteria (NTM) infection are increasing. However, the prevalence of NTM infection-associated comorbidities remains understudied. Thus, we investigated the comorbidities associated with NTM infection using the National Health Insurance Service-National Sample Cohort (NHIS–NSC) 2.0 database of the National Health Insurance Service (NHIS).

Methods

In this case–control study, patients with NTM infection and controls aged 20–89 years of age were matched 1:4 by sex, age, region, and income. A total of 26 comorbidities were selected based on previous reports and claims data analysis. The distribution of comorbidities was compared between patients with NTM infection and controls by sex and age using logistic regression analysis.

Results

In total, 893 patients (379 men and 514 women) with NTM infection (mean age, 56.1 years) and 3,572 controls (mean age, 55.6 years) were included. The odds ratio for prevalence of respiratory diseases, metabolic diseases, musculoskeletal disorders, gastrointestinal diseases, skin diseases, mental diseases, and neoplasms was significantly higher in patients with NTM infection than in the control group. Among comorbid diseases, the odds ratios (ORs) for the prevalence of the respiratory diseases such as bronchiectasis (OR [95% confidence interval (CI)]: 26.79 [19.69–36.45]) and interstitial pneumonitis (OR [95% CI]: 15.10 [7.15–31.89]) were the highest. No significant differences were observed in NTM infection-related comorbidities between men and women. In the younger age group (20–39 years old), the prevalence of respiratory and systemic diseases such as hypertension and diabetes was higher in the patient group than in the control group.

Conclusions

NTM infection is associated with several respiratory and systemic diseases that should be considered when providing medical care to patients with NTM infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02075-y.

Synergistic Interaction between Hyperuricemia and Abdominal Obesity as a Risk Factor for Metabolic Syndrome Components in Korean Population

BACKGROUND

The present study investigated the role of synergistic interaction between hyperuricemia and abdominal obesity as a risk factor for the components of metabolic syndrome.

METHODS

We performed a cross-sectional study using the data of 16,094 individuals from the seventh Korean National Health and Nutrition Examination Survey (2016 to 2018). The adjusted odds ratios of metabolic syndrome and its components were analyzed by multivariate logistic regression analysis. The presence of synergistic interaction between hyperuricemia and abdominal obesity was evaluated by calculating the additive scales-the relative excess risk due to interaction, attributable proportion due to interaction, and synergy index (SI).

RESULTS

There was a synergistic interaction between hyperuricemia and abdominal obesity in hypertriglyceridemia (men: SI, 1.39; 95% confidence interval [CI], 1.01 to 1.98; women: SI, 1.61; 95% CI, 1.02 to 2.69), and low high-density lipoprotein cholesterol (HDL-C) (men: SI, 2.03; 95% CI, 1.41 to 2.91; women: SI, 1.70; 95% CI, 1.05 to 2.95). There was no significant synergistic interaction between hyperuricemia and abdominal obesity for the risk of high blood pressure (men: SI, 1.22; 95% CI, 0.85 to 1.77; women: SI, 1.53; 95% CI, 0.79 to 2.97), and hyperglycemia (men: SI, 1.03; 95% CI, 0.72 to 1.47; women: SI, 1.39; 95% CI, 0.75 to 2.57).

CONCLUSION

Hyperuricemia and abdominal obesity synergistically increased the risk of hypertriglyceridemia and low HDL-C in both sexes.

The reality of treatment for hyperuricemia and gout in Japan: A historical cohort study using health insurance claims data

Hyperuricemia causes gout and has also been associated with metabolic syndrome and cardiovascular disease. Uric acid‐lowering drugs (ULDs) are used to reduce uric acid levels for the treatment of hyperuricemia and gout. However, there is a lack of robust and real‐world data on the history and treatment of patients with newly diagnosed hyperuricemia or gout in Japan. This retrospective, longitudinal, historical cohort study determined the characteristics of patients with hyperuricemia and/or gout, and prescription of, and adherence to, ULDs using data from the JMDC Claims Database. The primary evaluation population included 64 677 patients with newly diagnosed hyperuricemia and/or gout. Of these, only 26 501 (41.0%) had a prescription for ULDs at diagnosis. Even when ULDs were prescribed, the persistence rate of prescriptions declined over time, with a 54.4% persistence rate for ULDs at 12 months after the index diagnosis. In subgroups of patients with or without hypertension and diabetes, the rate of ULD prescription continuation was significantly higher in those with comorbidities than in those without (76.8% vs. 42.6% in those with vs. without hypertension, and 78.7% vs. 52.2% in those with vs. without diabetes). These finding suggest that therapeutic interventions to lower serum uric acid levels are under‐utilized for patients with newly diagnosed hyperuricemia and/or gout in Japan.

Development of a risk prediction score for hypertension incidence using Japanese health checkup data

Hypertension is a risk factor for cardiovascular disease. We developed a simple scoring method for predicting future hypertension using health checkup data. A total of 41,902 participants aged 30-69 years without baseline hypertension who underwent annual health checkups (mean age, 52.3 ± 10.2 years; male, 47.7%) were included. They were randomly assigned to derivation (n = 27,935) and validation cohorts (n = 13,967) at a ratio of 2:1. In the derivation cohort, we performed multivariable logistic regression analysis and assigned scores to each factor significantly associated with 5-year hypertension. We evaluated the predictive ability of the scores using area under the curve (AUC) analysis and then applied them to the validation cohort to assess their validity. The score including items requiring blood sampling ranged from 0 to 14 and included seven indicators (age, body mass index, blood pressure, current smoking, family history of hypertension, diabetes, and hyperuricemia). The score not including items requiring blood sampling ranged from 0 to 12 and included five indicators (the above indicators, except diabetes and hyperuricemia). The score not including items requiring blood sampling was better; blood sampling did not improve diagnostic ability. The AUC of the score not including items requiring blood sampling was 0.76, with a sensitivity and specificity of 0.82 and 0.60, respectively, for scores ≥6 points. The incidence of hypertension gradually and constantly increased (from 0.9 to 49.6%) as the score increased from 0 to ≥10. Analysis in the validation cohort yielded similar results. We developed a simple and useful clinical prediction model to predict the 5-year incidence of hypertension among a general Japanese population. The model had reasonably high predictive ability and reproducibility.

Serum Uric Acid Might Be Positively Associated With Hypertension in Chinese Adults: An Analysis of the China Health and Nutrition Survey

Background: Previous studies have clarified the relationship between serum uric acid (SUA) and hypertension; most of previous studies suggest that elevated uric acid levels are associated with an increased risk of hypertension, while in China, there are relatively few studies to explore above association. The objective of this longitudinal study is to investigate the correlation of SUA and hypertension in Chinese adults with a nationwide large-scale sample.

Methods: Data from the China Health and Nutrition Survey 2009, 2011, and 2016 were used; a total of 8,469 participants (3,973 men and 4,496 women) were involved. This study was conducted separately by gender. Clinical characteristics of the participants among different uric acid groups are compared. The binary logistic regression analysis was conducted to examine the association between SUA and hypertension. Restricted cubic spline analysis with three knots of the SUA concentration were used to characterize the dose-response relationship. Additionally, we compared the incidence of hypertension in the different baseline uric acid groups during follow-up in 2011 and 2015.

Results: After the covariates were fully adjusted, we found that elevated uric acid levels were correlated with increased risk of hypertension in both males (p < 0.01) and females (p < 0.01). With 2-year or 6-year of follow-up, we found participants with higher baseline uric acid levels had a higher incidence of hypertension (p < 0.01). In stratified analysis by obesity, above relationship remained significant in nonobesity population (males: p < 0.05, females: p < 0.01) and became nonsignificant in obesity people. In stratified analysis by age, above positively correlation remained significant in middle-aged men (p < 0.05) and elderly women (p < 0.01). Restricted cubic spline revealed the dose-response relationship between SUA and hypertension; we also found that above relationship was much stronger in females.

Conclusion: This study suggests that elevated SUA levels might be positively associated with an increased risk of hypertension in general Chinese adults.

Serum Uric Acid Levels and Their Changes and Risk of Stroke: A 7-Year Prospective Cohort Study in Northwest China

INTRODUCTION

It is not clear whether serum uric acid (SUA) levels and their changes over time are associated with the risk of stroke. A 7-year prospective cohort study in northwest China was conducted to analyze effects of SUA and their changes on the risk of stroke.

METHODS

A total of 23,262 individuals without cardiovascular disease in the Jinchang cohort were followed up for an average of 5.26 years. The Cox proportional hazard model was used to estimate the hazard ratios (HRs) and 95% confidence interval (95% CI) of stroke incidence to SUA and relative changes in SUA. Sensitivity analysis was performed after controlling the effect of renal insufficiency.

RESULTS

Baseline SUA and relative changes in SUA were positively correlated with the incidence of stroke in both males and females (p for overall association <0.0001). Stroke risk increased by 4.6% per 10% increase in the relative change of SUA (HR = 1.046, 95% CI, 1.007-1.086). The fully adjusted regression analysis demonstrated that only the large gain (>30%) in SUA was associated with an increased risk of stroke by 36.5% (95% CI, 1.8-83.0%), compared with the reference group (participants within ±10% changes in SUA). The same trend was observed in people with normal baseline SUA. In the unadjusted model, the risk of stroke associated with elevated SUA was significantly higher in the hyperuricemia group than in the normal SUA group.

CONCLUSION

High initial SUA concentration and an increase in SUA concentration over time would increase the risk of stroke, and this means that there is no safe increase in SUA.

The Relationship Between Elevated Serum Uric Acid and Risk of Stroke in Adult: An Updated and Dose-Response Meta-Analysis

Background: Uric acid (UA) is proposed as a potential risk factor for stroke in adult, yet the results from published studies are not generally accordant.

Method: We included prospective studies that explored the relationship between serum UA (SUA) and strokes. In this study, strokes include ischemic stroke and hemorrhagic stroke, which consists of intracerebral hemorrhage and subarachnoid hemorrhage. The effect-size estimates were expressed as hazard ratio (HR) and 95% confidence interval (CI). Sensitivity and subgroup analyses were performed to assess the robustness of the pooled estimation and potential sources of heterogeneity between studies.

Results: We meta-analyzed 19 prospective cohort articles, which involve 37,386 males and 31,163 females. Overall analyses results showed a significant association between a 1 mg/dl increase in high levels of SUA and the risk of total stroke (HR = 1.13; 95% CI: 1.09–1.18; P < 0.001), ischemic stroke (HR = 1.15; 95% CI: 1.10–1.21; P < 0.001), and hemorrhagic stroke (HR = 1.07; 95% CI: 1.00 to 1.15; P = 0.046). No significant difference was found between ischemic stroke and hemorrhagic stroke. In the subgroup analyses, the association of high SUA levels and the risk of total stroke was statistically significant in females (HR = 1.19; 95% CI: 1.12–1.26; P < 0.001) and males (HR = 1.11; 95% CI: 1.05–1.17; P < 0.001). Coincidentally, the association was also statistically significant for ischemic stroke, both in females (HR = 1.26; 95% CI: 1.17–1.36; P < 0.001) and in males (HR = 1.12; 95% CI: 1.06–1.19; P < 0.001). However, for hemorrhagic stroke, it was only statistically significant in females (HR = 1.19; 95% CI: 1.04–1.35; P = 0.01). Our dose–response research indicated the J-shaped trend between the ascending SUA levels and the higher risk of suffering from a stroke.

Conclusions: Our findings indicate that elevated SUA is a significant risk factor for adult stroke, both for ischemic stroke and hemorrhagic stroke, and especially in females.

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.

Individual and combined association analysis of famine exposure and serum uric acid with hypertension in the mid-aged and older adult: a population-based cross-sectional study

Background

Malnutrition in early life may affect health in later life. The associations between malnutrition and serum uric acid (SUA) and hypertension were inconsistent. The present study aimed to investigate the individual and combined association between famine exposure and serum uric acid and hypertension in middle-aged and older Chinese.

Methods

Data were selected from the China Health and Retirement Longitudinal Study (CHARLS) Wave2011. The analytic sample included 9368 individuals aged 45 to 90. Differences between baseline characteristics and famine exposure/SUA level were evaluated using the Chi-square test, t-test, and F-test. Then, the differences in the prevalence of hypertension between characteristic groups was also estimated by the Chi-square and t-test. Finally, multivariable-adjusted logistic regression models examined association of famine exposure and serum uric acid with odds of prevalence of hypertension.

Results

A total of 9368 individuals were enrolled in the study, 4366 (46.61%) and 5002 (53.39%) were male and female, respectively. Among males, 459 (10.51%) had been exposed to the Chinese famine during the fetal stage, whereas 1760 (40.31%) and 1645 (37.68%) had been exposed to the famine during childhood and adolescence/adult stage, respectively. Among females, 635 (12.69%) had been exposed to the Chinese famine during the fetal stage, whereas 1988 (39.74%) and 1569 (31.37%) had been exposed to the famine during childhood and adolescence/adult stage, respectively. Regarding the participants with SUA level measurements, 290 (6.64%) reported having Hyperuricemia (HUA) in males and 234 (4.68%) in the females. Furthermore, 1357 (31.08%) reported having hypertension in male and 1619 (32.37%) in the female. In multivariable-adjusted model, famine exposure and serum uric acid were associated with prevalence of hypertension independently in total populations [(1) Model four^d, fatal exposed group vs non-exposed group: 1.25 (95% CI 1.03, 1.52); childhood-exposed group vs non-exposed group:1.60 (95% CI 1.37, 1.87); adolescence/adult exposed group vs non-exposed group: 2.87 (95% CI 2.44, 3.37), P for trend < 0.001; (2) Model four ^e, high vs normal:1.73 (95% CI 1.44, 2.08)]. When stratified by sex, the results in both males and females were similar to those in the total population. In general, interaction analysis in the multivariable-adjusted model, compared with the combination of normal SUA level and no-exposed famine stage, all groups trended towards higher odds of prevalence of hypertension [the greatest increase in odds, adolescence/adult exposed stage and high SUA level in total participants: OR4.34; 95%CI 3.24, 5.81; P for interaction < 0.001]. When stratified by sex, the results in both males and females were also similar to those in the total population.

Conclusion

Our data support a strongly positive individual and combined association of famine exposure and serum uric acid with hypertension in middle-aged and elderly Chinese.

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.

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

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

Association of childhood anthropometric measurements and laboratory parameters with high blood pressure in young adults

Early intervention to manage high blood pressure (BP) in young adulthood is a promising approach for the prevention of future cardiovascular diseases. We aimed to examine the ability of childhood health information to predict the incidence of young adults with high BP. This cohort study included baseline clinical data of Japanese individuals aged 12-13 years. A total of 1129 participants were followed up for an average of 8.6 years. We examined the association of childhood variables consisting of body weight, body mass index, systolic BP, white blood cell count, red blood cell count, hemoglobin, hematocrit, platelet count, uric acid, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol with the development of high BP defined as ≥120/80 mmHg at 18-22 years old. At follow-up, the prevalence of high BP was 42.2% in men and 7.7% in women. Young men with high BP had childhood baseline characteristics that included higher body weight, body mass index, systolic BP, red blood cell count, hemoglobin, hematocrit, and uric acid than normotensive men. Young women with high BP had higher body weight, systolic BP, and uric acid at baseline. Multivariable logistic regression analysis revealed that a model including body weight, systolic BP, hematocrit, and uric acid had the highest predictive power (AUC 0.65 [95% CI, 0.62-0.69]) for men, and a model including body weight, systolic BP, and uric acid had the highest predictive power (AUC 0.70 [95% CI, 0.58-0.81]) for women. Comprehensive childhood health information contributes to the prediction of high BP in young adults.

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 between serum copper levels and prevalence of hyperuricemia: a cross-sectional study

Hyperuricemia has been recognized as a worldwide public health concern. This study was conducted to examine the association between serum copper (Cu) concentration and the prevalence of hyperuricemia in a middle-aged and elderly population. Serum Cu concentration was measured by Roche modular P800 using the PAESA method. Serum uric acid (UA) concentration was detected by a Beckman Coulter AU 5800. Presence of hyperuricemia was defined as serum UA ≥ 416 μmol/L for men and ≥360 μmol/L for women. The association between serum Cu concentration and the prevalence of hyperuricemia was evaluated by logistic regression. The prevalence of hyperuricemia was 17.6% (n = 6,212) in the present study. Relative to the lowest quintile, the age- and sex-adjusted odds ratios for hyperuricemia were 1.38 (95% CI: 1.12 to 1.70), 1.34 (95% CI: 1.07 to 1.66), and 1.53 (95% CI: 1.23 to 1.91) in the third, fourth, and fifth serum Cu concentration quintiles (P for trend < 0.001). Similar results were found both in men and women subgroups. None of the findings were materially altered after adjustment for additional potential confounders. In conclusion, in this population-based cross-sectional study, serum Cu concentration was positively associated with the prevalence of hyperuricemia.

Hyperuricemia and Hypertension: Links and Risks

Hyperuricemia has long been recognized to be associated with increased cardiovascular risk, including risk of developing hypertension. Epidemiological findings suggest that the link with hypertension is stronger in children and adolescents. Uric acid acts as a strong antioxidant compound in the extracellular environment but has pro-inflammatory effects within the intracellular setting. A chronic phase of microvascular injury is known to occur after prolonged periods of hyperuricemia. This is proposed to contribute to afferent arteriolopathy and elevation of blood pressure that may become unresponsive to uric acid-lowering therapies over time. Studies have struggled to infer direct causality of hyperuricemia due to a vast number of confounders including body mass index. The aim of this review is to present the available data and highlight the need for large scale prospective randomized controlled trials in this area. At present, there is limited evidence to support a role for uric acid-lowering therapies in helping mitigate the risk of hypertension.

Association Between Serum Uric Acid Levels and Benign Paroxysmal Positional Vertigo: A Systematic Review and Meta-Analysis of Observational Studies

Objective: The objective of the present study was to meta-analyze relevant literature to gain a comprehensive understanding of the potential relationship between serum uric acid levels and risk of benign paroxysmal positional vertigo (BPPV).

Methods: The databases of PubMed, Web of Science, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed were systematically searched for observational case-control studies of the association between BPPV and serum uric acid levels published up to October 2018. Data from eligible studies were meta-analyzed using Stata 12.0.

Results: A total of 12 studies were included in the analysis. There was a strong tendency for serum uric acid levels to be associated with risk of BPPV among studies conducted in China (OR 0.69, 95%CI 0.01–1.40, p = 0.053), but not among studies outside China (OR 1.07, 95%CI 1.08–3.22, p = 0.33). Across all studies, serum uric acid level was significantly higher among individuals with BPPV than among controls (OR 0.78, 95%CI 0.15–1.41, p = 0.015), yet it did not independently predict risk of the disorder (OR 1.003, 95%CI 0.995–1.012, p = 0.471).

Conclusion: The available evidence suggests that BPPV is associated with elevated levels of serum uric acid, but these levels may not be an independent risk factor of BPPV.