Relationship between uric acid and blood pressure in different age groups

Hyperuricemia and associated factors among hypertensive patients attending an academic hospital of Ethiopia: A cross-sectional study

Background

Hypertension is a major public health problem in developing countries. Globally, nearly 1.13 billion adults had hypertension in 2015 and this is estimated to increase to 1.56 billion by 2025. Hyperuricemia is an important predictor of the progression of hypertension and is common in hypertensive patients. Hypertensive patients with hyperuricemia are at higher risk of cardiovascular disease.

Objective

To assess the prevalence of hyperuricemia and its associated factors among hypertensive patients attending the University of Gondar Comprehensive Specialized Hospital (UGCSH).

Method

An institutional-based cross-sectional study was conducted on 248 hypertensive patients attending the University of Gondar Comprehensive Specialized Hospital from January 2020 to February 2021. A convenient sampling technique was employed to select study participants. Socio-demographic and clinical characteristics were collected using a structured questionnaire via face-to-face interviews and reviewing medical records respectively. The biochemical parameters were measured by using a Mindray BS-200E chemistry analyzer. Data was entered using EpiData version 4.6.0.0 and analyzed using STATA vs. 14.0. Bivariable and multivariable binary logistic regression were fitted to identify factors associated with hyperuricemia. The odds ratio and 95 % CI were calculated to assess the strength of the association and a P-value <0.05 in the multivariable was considered statistically significant.

Results

A total of 248 patients were enrolled; 140 (56.5 %) were female. The mean age of patients was 57.9 ± 10.5 years. The overall prevalence of hyperuricemia was 42.3 %; males had a prevalence of 36.1 % and females of 47.1 %. High waist circumference, high body mass index, dyslipidemia, low estimated Glomerular Filtration Rate, elevated fasting blood glucose, elevated total cholesterol, elevated triglycerides, elevated Low-Density Lipoprotein cholesterol, and Low High-Density Lipoprotein cholesterol were found to be significantly associated with hyperuricemia.

Conclusion

This study demonstrated the predominant existence of hyperuricemia in hypertensive patients. Therefore, early diagnosis and monitoring of hyperuricemia are required before further complications occur.

Hyperuricemia - consequences of not initiating therapy. Benefits and drawbacks of treatment

Hyperuricemia, characterized by elevated levels of uric acid in the body, is associated with several health risks, including gout, urolithiasis and cardiovascular disease. Although treatment options are available, they can lead to hypersensitivity reactions, particularly with allopurinol therapy. This paper provides a comprehensive review of the consequences of hyperuricemia, the need for treatment and the potential adverse effects of allopurinol, illustrated by a case study. The study highlights the importance of careful consideration before initiating therapy, particularly in patients with comorbidities and concomitant medication. It emphasizes the need for vigilant monitoring and individualized treatment approaches to reduce adverse effects. In addition, genetic factors, particularly HLA-B*5801, play an important role in determining susceptibility to allopurinol hypersensitivity reactions. This paper highlights the importance of informed decision making in the management of hyperuricemia to optimize patient outcomes while minimizing the risks associated with treatment.

Comparison of metabolic syndrome prevalence and characteristics using five different definitions in China: a population-based retrospective study

Background

Metabolic syndrome (MetS) is on the rise in developing countries and is characterized by a series of indications of metabolic disturbance. However, the prevalence of MetS varies under different definitions. The study aimed to compare five definitions of MetS in the China adult population, to explore their prevalence, characteristics and agreement.

Methods

The data for the retrospective study came from the China Health and Retirement Longitudinal Study (CHARLS), consisting of 9,588 participants (≥45). MetS definitions from International Diabetes Federation (IDF) (2006), National Cholesterol Education Program Adult Treatment Panel III (ATPIII) (2005), National Cholesterol Education Program Adult Treatment Panel III (ATPIII) (2001), Chinese Diabetes society (CDS) (2004) and the World Health Organization (WHO) (1999). We used binary and multivariable logistic analysis to explore factors connected with MetS.

Results

The five definitions of MetS led to different prevalence of MetS:34.52% by IDF (2006), 38.63% by ATP (2005), 25.94% by ATP (2001), 26.31% by CDS (2004), 21.57% by WHO (1999). According to the definition of IDF (2006) (22.32% vs. 45.06%), ATPIII (2005) definition (27.99% vs. 47.82%), ATPIII (2001) definition (15.37% vs. 35.07%), CDS (2004) definition (19.96% vs. 31.80%), and WHO (1999) definition (17.44% vs. 25.14%), the prevalence of MetS in men was low but in women was high. The agreement between the five definitions for men was good except for the IDF (2006) definition and ATPIII (2001) definition (kappa = 0.51), with kappa values from 0.64 to 0.85. For women, the agreement between the five definitions was good ranging from 0.67 to 0.95, however, except for the definition of CDS (2004) and the definition of IDF (2006) (kappa = 0.44), the definition of WHO (1999) and the definition of IDF (2006) (kappa = 0.55), and the definition of WHO (1999) and the definition of ATPIII (2005) (kappa = 0.54). Binary logistic analysis indicated that although the impact and relevance varied by sex and definition, age, education, marital status, current residence, current smoking, alcohol using, taking activities and number of chronic diseases were factors connected to MetS.

Conclusion

the prevalence and characteristics of the five definitions of MetS are different in the Chinese population. Therefore, it is vital to use the same definition for a country to diagnose MetS. On the other side, a lower prevalence in men than in women and the consistency of five MetS definitions are good in men but relatively poor in women.

Predicting metabolic syndrome by obesity- and lipid-related indices in mid-aged and elderly Chinese: a population-based cross-sectional study

Objective

To predict the optimal cut-off values for screening and predicting metabolic syndrome(MetS) in a middle-aged and elderly Chinese population using 13 obesity and lipid-related indicators, and to identify the most suitable predictors.

Methods

The data for this cross-sectional investigation came from the China Health and Retirement Longitudinal Study (CHARLS), including 9457 middle-aged and elderly people aged 45-98 years old. We examined 13 indicators, including waist circumference (WC), body mass index (BMI), waist-height ratio (WHtR), visceral adiposity index (VAI), a body shape index (ABSI), body roundness index (BRI), lipid accumulation product index (LAP), conicity index (CI), Chinese visceral adiposity index (CVAI), triglyceride-glucose index (TyG-index) and their combined indices (TyG-BMI, TyG-WC, TyG-WHtR). The receiver operating characteristic curve (ROC) was used to determine the usefulness of indicators for screening for MetS in the elderly and to determine their cut-off values, sensitivity, specificity, and area under the curve (AUC). Association analysis of 13 obesity-related indicators with MetS was performed using binary logistic regression analysis.

Results

A total of 9457 middle-aged and elderly Chinese were included in this study, and the overall prevalence of the study population was 41.87% according to the diagnostic criteria of NCEP ATP III. According to age and gender, the percentage of males diagnosed with MetS was 30.67% (45-54 years old: 30.95%, 55-64 years old: 41.02%, 65-74 years old: 21.19%, ≥ 75 years old: 6.84%). The percentage of females diagnosed with MetS was 51.38% (45-54 years old: 31.95%, 55-64 years old: 39.52%, 65-74 years old: 20.43%, ≥ 75 years old: 8.10%). The predictive power of Tyg-related parameters was more prominent in both sexes. In addition, LAP and CVAI are also good at predicting MetS. ABSI had a poor prediction ability.

Conclusions

Among the middle-aged and elderly population in China, after adjusting for confounding factors, all the indicators except ABSI had good predictive power. The predictive power of Tyg-related parameters was more prominent in both sexes. In addition, LAP and CVAI are also good at predicting MetS.

Predicting hypertension by obesity- and lipid-related indices in mid-aged and elderly Chinese: a nationwide cohort study from the China Health and Retirement Longitudinal Study

BACKGROUND

Currently, the study outcomes of anthropometric markers to predict the risk of hypertension are still inconsistent due to the effect of racial disparities. This study aims to investigate the most effective predictors for screening and prediction of hypertension (HTN) in the Chinese middle-aged and more elderly adult population and to predict hypertension using obesity and lipid-related markers in Chinese middle-aged and older people.

METHODS

The data for the cohort study came from the China Health and Retirement Longitudinal Study (CHARLS), including 4423 middle-aged and elderly people aged 45 years or above. We examined 13 obesity- and lipid-related indices, including waist circumference (WC), body mass index (BMI), waist-height ratio (WHtR), visceral adiposity index (VAI), a body shape index (ABSI), body roundness index (BRI), lipid accumulation product index (LAP), conicity index (CI), Chinese visceral adiposity index (CVAI), triglyceride-glucose index (TyG-index) and their combined indices (TyG-BMI, TyG-WC, TyG-WHtR). To compare the capacity of each measure to forecast the probability of developing HTN, the receiver operating characteristic curve (ROC) was used to determine the usefulness of anthropometric indices for screening for HTN in the elderly and determining their cut-off value, sensitivity, specificity, and area under the curve (AUC). Association analysis of 13 obesity-related anthropometric indicators with HTN was performed using binary logistic regression analysis.

RESULTS

During the four years, the incident rates of HTN in middle-aged and elderly men and women in China were 22.08% and 17.82%, respectively. All the above 13 indicators show a modest predictive power (AUC > 0.5), which is significant for predicting HTN in adults (middle-aged and elderly people) in China (P < 0.05). In addition, when WHtR = 0.501 (with an AUC of 0.593, and sensitivity and specificity of 63.60% and 52.60% respectively) or TYg-WHtR = 4.335 (with an AUC of 0.601, and sensitivity and specificity of 58.20% and 59.30% respectively), the effect of predicting the incidence risk of men is the best. And when WHtR = 0.548 (with an AUC of 0.609, and sensitivity and specificity of 59.50% and 56.50% respectively) or TYg-WHtR = 4.781(with an AUC of 0.617, and sensitivity and specificity of 58.10% and 60.80% respectively), the effect of predicting the incidence risk of women is the best.

CONCLUSIONS

The 13 obesity- and lipid-related indices in this study have modest significance for predicting HTN in Chinese middle-aged and elderly patients. WHtR and Tyg-WHtR are the most cost-effective indicators with moderate predictive value of the development of HTN.

Obesity-and lipid-related indices as a predictor of hypertension in Mid-aged and Elderly Chinese: A Cross-sectional Study

Objective

Middle-aged and elderly people in China probably suffer from hypertension. There is a close relationship between obesity-and lipid-related index and hypertension, which is recognized by recent studies. However, these studies have not systematically compared the relationship between the two. We aim to find the most effective obesity-and lipid-related index for predicting hypertension.

Method

A total of 9488 middle-aged and elderly people in China participated in this study. In this study, the subjects were divided into male and female groups by the definition of the 2018 Chinese Guidelines for Prevention and Treatment of Hypertension. Searching for the best predictors among 13 obesity-and lipid-related indicators through binary logistic regression analyses and receiver operator curve (ROC). These 13 indicators are body mass index (BMI), waist circumference (WC), waist-height ratio (WHtR), conicity index (CI), visceral adiposity index (VAI), Chinese visceral adiposity index (CVAI), lipid accumulation product (LAP), a body shape index (ABSI), body roundness index (BRI), triglyceride glucose index (TyG-index) and its correlation index (TyG-BMI, TyG-WC, TyG-WHtR).

Results

After adjusting bias, all 13 indexes are risk factors for hypertension. In ROC curve analysis, thirteen obesity-and lipid-related factors can predict the occurrence of hypertension. Among them, CVAI has the best prediction effect (male: AUC = 0.660, female: AUC = 0.699). AUC for WHtR was equal to that for BRI and TyG - WHtR in identifying hypertension in male. Similarly, AUC of TyG-BMI and BMI were the same. In females, AUC for WHtR and BRI were the same when predicting hypertension. AUC of ABSI was much lower than other test indexes.

Conclusion

In predicting hypertension, thirteen obesity-and lipid-related factors are effective. In addition, in males and females, CVAI is the best indicator to indicate hypertension. TyG-WHtR, WHtR, and BRI performed well in predicting metabolic syndrome in both males and females. ABSI has a poor ability to predict hypertension.

Obesity- and lipid-related indices as a predictor of obesity metabolic syndrome in a national cohort study

Objective

Metabolic syndrome is a common condition among middle-aged and elderly people. Recent studies have reported the association between obesity- and lipid-related indices and metabolic syndrome, but whether those conditions could predict metabolic syndrome is still inconsistent in a few longitudinal studies. In our study, we aimed to predict metabolic syndrome by obesity- and lipid-related indices in middle-aged and elderly Chinese adults.

Method

A national cohort study that consisted of 3,640 adults (≥45 years) was conducted. A total of 13 obesity- and lipid-related indices, including body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), conicity index (CI), visceral adiposity index (VAI), Chinese visceral adiposity index (CVAI), lipid accumulation product (LAP), a body shape index (ABSI), body roundness index (BRI), and triglyceride glucose index (TyG-index) and its correlation index (TyG-BMI, TyG-WC, and TyG-WHtR), were recorded. Metabolic syndrome (MetS) was defined based on the criteria of the National Cholesterol Education Program Adult Treatment Panel III (2005). Participants were categorized into two groups according to the different sex. Binary logistic regression analyses were used to evaluate the associations between the 13 obesity- and lipid-related indices and MetS. Receiver operating characteristic (ROC) curve studies were used to identify the best predictor of MetS.

Results

A total of 13 obesity- and lipid-related indices were independently associated with MetS risk, even after adjustment for age, sex, educational status, marital status, current residence, history of drinking, history of smoking, taking activities, having regular exercises, and chronic diseases. The ROC analysis revealed that the 12 obesity- and lipid-related indices included in the study were able to discriminate MetS [area under the ROC curves (AUC > 0.6, P < 0.05)] and ABSI was not able to discriminate MetS [area under the ROC curves (AUC < 0.6, P > 0.05)]. The AUC of TyG-BMI was the highest in men, and that of CVAI was the highest in women. The cutoff values for men and women were 187.919 and 86.785, respectively. The AUCs of TyG-BMI, CVAI, TyG-WC, LAP, TyG-WHtR, BMI, WC, WHtR, BRI, VAI, TyG index, CI, and ABSI were 0.755, 0.752, 0.749, 0.745, 0.735, 0.732, 0.730, 0.710, 0.710, 0.674, 0.646, 0.622, and 0.537 for men, respectively. The AUCs of CVAI, LAP, TyG-WC, TyG-WHtR, TyG-BMI, WC, WHtR, BRI, BMI, VAI, TyG-index, CI, and ABSI were 0.687, 0.674, 0.674, 0.663, 0.656, 0.654, 0.645, 0.645, 0.638, 0.632, 0.607, 0.596, and 0.543 for women, respectively. The AUC value for WHtR was equal to that for BRI in predicting MetS. The AUC value for LAP was equal to that for TyG-WC in predicting MetS for women.

Conclusion

Among middle-aged and older adults, all obesity- and lipid-related indices, except ABSI, were able to predict MetS. In addition, in men, TyG-BMI is the best indicator to indicate MetS, and in women, CVAI is considered the best hand to indicate MetS. At the same time, TyG-BMI, TyG-WC, and TyG-WHtR performed better than BMI, WC, and WHtR in predicting MetS in both men and women. Therefore, the lipid-related index outperforms the obesity-related index in predicting MetS. In addition to CVAI, LAP showed a good predictive correlation, even more closely than lipid-related factors in predicting MetS in women. It is worth noting that ABSI performed poorly, was not statistically significant in either men or women, and was not predictive of MetS.

Assessment of the relationship between serum xanthine oxidase levels and type 2 diabetes: a cross-sectional study

Xanthine oxidase (XO) is an enzyme associated with purine metabolism. The relationship between XO levels and type 2 diabetes (T2D) is not clear yet or little is known so far. Therefore, we conducted a cross-sectional study to determine the association of XO levels with T2D in a Bangladeshi adult cohort. A total of 325 participants (234 males and 91 females) were enrolled in the study. The participants were divided into three groups; diabetic (n = 173), prediabetic (n = 35), and non-diabetic control (n = 117). Serum levels of XO were measured by enzyme-linked immunosorbent assay (ELISA) and other biochemical parameters including fasting blood glucose (FBG), serum uric acid (SUA), and lipid profile markers measured by colorimetric methods. Participants with T2D were confirmed according to the definition of the American Diabetic Association. The association between serum XO levels and T2D was determined by logistic regression models. The mean level of serum XO was significantly higher in females (6.0 ± 3.7 U/L) compared to male (4.0 ± 2.8 U/L) participants (p < 0.001). In contrast, males had a higher mean level of SUA (6.1 ± 1.9 mg/dL) than female (4.4 ± 1.9 mg/dL) participants (p < 0.001). The mean level of XO was significantly higher in the diabetic group (5.8 ± 3.6 U/L) compared to the prediabetic (3.7 ± 1.9 U/L) and control (2.9 ± 1.8 U/L) groups (p < 0.001). On the other hand, the mean SUA concentration was significantly lower in the diabetic group than in the other two groups (p < 0.001). A significant increasing trend was observed for FBG levels across the XO quartiles (p < 0.001). A decreasing trend was found for SUA levels in the XO quartiles (p < 0.001). Serum levels of XO and SUA showed a positive and negative correlation with FBG, respectively. In regression analysis, serum XO levels showed an independent association with T2D. In conclusion, this study reports a positive and independent association between XO levels and T2D in Bangladeshi adults. Monitoring serum levels of XO may be useful in reducing the risk of T2D. Further research is needed to determine the underlying mechanisms of the association between elevated XO levels and T2D.

Gene Dose-Dependent and Additive Effects of ABCG2 rs2231142 and SLC2A9 rs3733591 Genetic Polymorphisms on Serum Uric Acid Levels

This study aimed to evaluate whether the single nucleotide polymorphisms of ATP-binding cassette subfamily G member 2 (ABCG2) and solute carrier family 2 member 9 (SLC2A9) affect individual blood uric acid levels using pyrosequencing. ABCG2 (rs2231142, rs72552713, rs2231137), SLC2A9 (rs3734553, rs3733591, rs16890979), and individual uric acid levels were prospectively analyzed in 250 healthy young Korean male participants. Prominent differences in uric acid levels of the alleles were observed in the SLC2A9 rs3733591 polymorphism: wild-type (AA) vs. heterozygote (AG), 0.7 mg/dL (p < 0.0001); AA vs. mutant type (GG), 1.32 mg/dL (p < 0.0001); and AG vs. GG, 0.62 mg/dL (p < 0.01). In ABCG2 single nucleotide polymorphisms (SNPs), the statistically significant differences in uric acid levels were only found in rs2231142 between CC vs. AA (1.06 mg/dL; p < 0.001), and CC vs. CA (0.59 mg/dL; p < 0.01). Serum uric acid levels based on the ABCG2 and SLC2A9 diplotype groups were also compared. The uric acid levels were the lowest in the CC/AA diplotype and highest in the AA/AG diplotype. In addition, the SNP SLC2A9 rs3733591 tended to increase the uric acid levels when the ABCG2 rs2231142 haplotypes were fixed. In conclusion, both the ABCG2 rs2231142 and SLC2A9 rs3733591 polymorphisms may additively elevate blood uric acid levels.

Uric acid and blood pressure in NHANES dated from 2009 to 2018: A cross-sectional research

BACKGROUND AND AIM

This study aimed to explore the association between uric acid (UA) and blood pressure (BP), included systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP).

METHODS AND RESULTS

A cross-sectional study with 22,478 individuals aged from 12 to 80 years (11,443 males and 11,035 females) from the National Health and Nutrition Examination Survey (NHANES) was performed. Multiple linear regression analysis was applied to explore the relationship between UA and BP, Stratified analysis and interaction were performed based on gender, race, age, body mass index (BMI), and alcohol consumption. Significantly positively associations were presented in SBP(β, 0.84 [95% CI, 0.67, 1.00]), DBP(β, 0.23 [95% CI, 0.11, 0.36]), and MAP (β, 0.43 [95% CI, 0.31, 0.55]). The associations were much more stronger between UA and SBP in females (β, 1.04 [95% CI, 0.78, 1.30], p for interaction 0.0003), black group (β, 1.17 [95% CI, 0.77, 1.56], p for interaction 0.0296), age (≥45) group (β, 1.03 [95% CI, 0.68, 1.39], p for interaction <0.0001) and drinking group (β, 0.98 [95% CI, 0.75, 1.21], p for interaction <0.0001). The significant interactions were found between UA and DBP in gender and alcohol consumption (all p for interaction <0.05). In terms of MAP, the significant interactions were found in race, age, and alcohol consumption (all p for interaction <0.05).

CONCLUSIONS

A significantly positively association was found between UA and BP, including SBP, DBP, and MAP.

Validation of age- and sex-dependent association of uric acid and incident hypertension in rural areas

Background

A previous study based on urban areas suggested the age- and sex-dependent association of uric acid (UA) and incident hypertension. We aimed to investigate whether this association is valid even in rural areas with different lifestyle.

Methods

Data from the cardiovascular disease association study, a prospective cohort study based on rural residents, was analyzed. A total of 4,592 subjects (mean age, 60.1 ± 9.5 years; men, 37.7%) without hypertension were included. We first investigated whether UA was a risk factor for incident hypertension using Cox regression, and then compared the relative risk by stratification according to age and sex.

Results

During the follow-up period (mean, 2.0 years), 579 subjects (12.6%) were newly diagnosed with hypertension. The risk factors for incident hypertension were age (Hazard ratios [HR] for ≥ 65, 1.26), systolic blood pressure (HR per 1 mmHg increase, 1.07), and serum UA concentration (HR per 1 mmHg increase, 1.10). The risk of UA-related incident hypertension was higher in the non-elderly than in the elderly for both men and women (HR, 1.74 for non-elderly men; 1.88 for non-elderly women; 1.66 for elderly men; 1.10 for elderly women). Even after adjusting for multiple confounders, the risk of UA-related incident hypertension was significantly higher in non-elderly women (HR, 1.59; P < 0.05).

Conclusions

Age- and sex-dependent association of UA with incident hypertension suggested in cohort study based on urban areas was consistently found in rural areas as well. In particular, non-elderly women were at a higher risk for UA-related incident hypertension.

Supplementary information

The online version contains supplementary material available at 10.1186/s40885-022-00206-5.

Hyperuricemia is independently associated with hypertension in men under 60 years in a general Chinese population

Hyperuricemia has been associated with hypertension, however, whether this association exists across all decades of adult life is unknown. This study aimed to assess the association between hyperuricemia and hypertension in relation to age. This retrospective cross-sectional study included a total of 22,556 adult Chinese people who attended Health Physical Examination in a Chinese hospital. Participants were aged between 18 and 95 years (mean [standard deviation], 45.4 [14.0]). Serum uric acid levels and blood pressure were measured. Associations between serum uric acid and blood pressure, and between hyperuricemia and hypertension diagnosis were analyzed using linear or logistic regression, adjusting for confounding risk factors including age, sex, total cholesterol, high-density lipoprotein cholesterol, and fasting blood glucose. Sub-analysis was stratified by age and sex. Before adjustment, high serum uric acid was associated with higher systolic blood pressure (β = 0.214, P < 0.001) and higher diastolic blood pressure (β = 0.271, P < 0.001). Hyperuricemia was associated with hypertension diagnosis (OR, 1.763; 95% CI, 1.635-1.901; P < 0.001) in an unadjusted analysis. These findings remained significant after adjusting for confounding factors. Sub-analysis suggested that the association between uric acid and blood pressure was weaker in older age groups and the association between hyperuricemia and hypertension was limited to people under 60 years. Hyperuricemia was independently associated with hypertension diagnosis in men but not in women, and the independent association between hyperuricemia and hypertension only presented in men under 60 years. This study suggests that hyperuricemia is independently associated with hypertension in Chinese men under 60 years.

A Study of Metabolic Parameters in Patients with Gout: A Single Center Study from Nepal

BACKGROUND AND AIMS

To study the prevalence of deranged metabolic parameters in patients with gout.

METHODS

This was a prospective, cross-sectional observational study conducted at a tertiary level rheumatology center in Nepal. Patients over 18 years and diagnosed as gout using the ACR/EULAR 2015 classification criteria were included in the study. Known cases of chronic kidney disease, liver disease and heart diseases were excluded. Baseline demographic data along with records of weight, waist circumference, lipid profile, glucose profile, blood pressure measurement, serum uric acid level and inflammatory markers were taken. Diagnosis of metabolic syndrome (MS) was made according to the National Cholesterol Education Program criteria. Approval was obtained from the ethical review board of the National Center for Rheumatic Diseases.

RESULTS

A total of 523 patients with gout were enrolled in the study, out of which 97.0% were male. The mean age at diagnosis was 49.1±12.8 years. Most of the patients were overweight with a mean BMI of 27.0±3.6 kg/m2. About 8.1% had preexisting diabetes mellitus, 24.6% had hypertension, 5.1% had hypothyroidism and 45.1% had dyslipidemia. Patients fulfilling 2 out of 5 criteria of MS were 60.6% whereas 30.6% fulfilled 3 out of 5 criteria.

CONCLUSION

Gout was commonly observed in middle-aged men. The prevalence of metabolic syndrome and its components was high in patients with gout. Management of gout should also include screening and management of the metabolic syndrome.

Age and sex dependent association of uric acid and incident hypertension

BACKGROUND AND AIMS

A previous meta-analysis suggested that the relationship between hyperuricemia and hypertension may be stronger in younger individuals and women. We aimed to investigate the age and sex dependent association of uric acid (UA) and incident hypertension.

METHODS AND RESULTS

We analyzed data from the Health Examinees Study, a community-based prospective cohort study conducted in Korea from 2004 to 2013. It included 29,088 non-hypertensive subjects aged 40-79 (age, 52.5 ± 7.8 years; men, 31.4%) who had serum UA measurement and participated in the follow-up survey. The risk factors of hypertension were assessed using Cox regression. Over a mean 3.8 years of follow-up, 1388 men (15.2%) and 1942 women (9.7%) were newly diagnosed with hypertension. Upon age- and sex-based stratification, the risk of hypertension was highest in hyperuricemic subjects aged 40-49 years (HR: women, 2.16; men, 1.30). Across the entire cohort, the risk of incident hypertension was higher in groups with higher serum UA levels, and highest in women aged 40-49 years (HR, 1.44; P < 0.001). On multivariable linear regression analysis, the higher the baseline serum UA level, the greater the increase in blood pressure during follow-up, and this effect was strongest in women aged 40-49 years (β = 0.87 and P < 0.01 for systolic blood pressure).

CONCLUSIONS

The relationship between uric acid and incident hypertension tended to be dependent on age and sex. Younger women are at highest risk of UA-related incident hypertension.

Asymptomatic hyperuricemia: is it really asymptomatic?

PURPOSE OF REVIEW

Hyperuricemia is highly prevalent, affecting approximately 38 million individuals in the United States. However, the significance of asymptomatic hyperuricemia - hyperuricemia in the absence of gout - continues to be debated.

RECENT FINDINGS

Asymptomatic hyperuricemia results in monosodium urate crystal deposition in tissues, which may promote chronic inflammation. Intracellularly, hyperuricemia inhibits the master regulator adenosine monophosphate (AMP)-associated protein kinase and may condition innate immune responses through durable epigenetic modifications. At the population level, asymptomatic hyperuricemia is associated with multiple comorbidities, including hypertension, chronic kidney disease, coronary artery disease, and diabetes; limitations of these studies include that most are retrospective and some do not rigorously distinguish between asymptomatic hyperuricemia and gout. Treatment studies suggest that urate lowering may reduce the risk of incidence or progression of some of these comorbidities; unfortunately, many of these treatment studies are small or flawed, and not all study results are consistent.

SUMMARY

Accumulating evidence suggests that asymptomatic hyperuricemia contributes to the comorbidities with which it associates and that proper asymptomatic hyperuricemia treatment may reduce future risk. Additional prospective trials are needed to definitely establish causality and support decision-making as to whether, and which patients with asymptomatic hyperuricemia would warrant urate-lowering treatment.

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 and cardiometabolic diseases

Hyperuricemia, which has been considered as a cause of gout and nephrolithiasis has recently been suggested to be associated with hypertension, coronary heart disease, heart failure, atrial fibrillation, insulin resistance, and nonalcoholic fatty liver disease. Several clinical and experimental studies have supported uric acid (UA) as an independent risk factor for predicting disease development along with the traditional risk factors. The mechanism by which UA causes cardiometabolic disease has not been fully elucidated to date; however, it has been explained by several hypotheses such as oxidative stress, reduced nitric oxide bioavailability, inflammation, endothelial dysfunction, and so on. Although evidence of the preventive and therapeutic effects of UA lowering therapy on cardiometabolic diseases is still insufficient, it is expected to be considered as a new treatment strategy for such diseases through additional, carefully designed, large-scale clinical studies.

Body mass index and serum uric acid level: Individual and combined effects on blood pressure in middle-aged and older individuals in China

Few studies on the individual and combined analysis between serum uric acid (SUA) and body mass index (BMI) and blood pressure (BP) were conducted in individuals aged ≥45 years. We aimed to assess the extent to which BMI and SUA and their interaction affect BP in Chinese middle-aged and older adults.Data were selected from the China Health and Retirement Longitudinal Study (CHARLS). A total of 5888 individuals aged 45 to 96 was included. Differences between BMI, or between categories of blood pressure were evaluated by t test or chi-square test. The trend of related variables according to four BMI categories was also tested using contrast analysis. The adjusted associations between various characteristics and BP status were first compared using linear regression models, as appropriate. Then, general linear models adjusting for related potential confounders were used to examine the synergistic effect of SUA and BMI level on BP for middle-aged and elderly individuals in China.Age-adjusted partial Pearson correlation coefficient showed that BMI was significantly and positively correlated with BP both in male and female, SUA positively correlated with both systolic blood pressure (SBP) and diastolic blood pressure (DBP) in males with BMI <24.0 kg/m and females with BMI <24.0 kg/m. However, SUA level significantly and positively correlated with DBP, but not with SBP, in females with BMI ≥24.0 kg/m. Multiple linear regression analysis showed that BMI was independently associated with BP both in male and female, SUA significantly and positively associated with SBP in both males and females with BMI <24.0 kg/m, However, SUA level positively correlated with DBP in females with BMI <24.0 kg/m, but not with males with BMI <24.0 kg/m, independent of other confounding factors. A general linear model analysis adjusted for confounding factors did not reveal interaction between BMI, SUA levels and SBP (β=-1.404, P = .686 in males; β=-2.583, P = .575 in females) and DBP (β=-2.544, P = .263 in males; β=-2.619, P = .622 in females).No interaction between BMI, SUA levels, and BP was observed in either males or females; However, BMI was independently associated with BP both in male and female, SUA independently associated with SBP both in males and females with BMI <24.0 kg/m, and SUA independently associated with DBP in females with BMI ≥24.0 kg/m.

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.

The causal role of elevated uric acid and waist circumference on the risk of metabolic syndrome components

BACKGROUND/OBJECTIVES

Hyperuricemia has been found to cluster with multiple components of metabolic syndrome (MetS). It is unclear whether hyperuricemia is a downstream result of MetS or may play an upstream role in MetS development. Using the Mendelian randomization (MR) method, we examined the causal relationship between elevated uric acid and the various components of MetS with waist circumference as a positive control.

SUBJECTS/METHODS

Data from 10k participants of Taiwan Biobank was used to carry out MR analysis with uric acid risk score (wGRS) and waist circumference wGRS as instrumental variables and components of MetS as the outcomes.

RESULTS

We found that genetically increased serum uric acid corresponds to a significant increment of triglyceride (β = 0.065, p < 0.0001), systolic blood pressure (β = 1.047, p = 0.0005), diastolic blood pressure (β = 0.857, p < 0.0001), and mean arterial pressure (β = 0.920, p < 0.0001), but a significant reduction of high-density lipoprotein cholesterol (β = -0.020, p = 0.0014). Uric acid wGRS was not associated with fasting serum glucose, HbA1C, waist circumference, or BMI. On the other hand, waist circumference was causally associated with all the components of MetS including uric acid.

CONCLUSIONS

Our MR investigation shows that uric acid increment may augment the risk of MetS through increasing blood pressure and triglyceride levels and lowering HDL-C value but not through accumulating fat or hyperglycemia. High waist circumference may be a causal agent for all the components of MetS including hyperuricemia.

Relationship between serum uric acid and hypertension: a cross-sectional study in Bangladeshi adults

Experimental evidence suggests a causal role of serum uric acid (SUA) in hypertension development. Currently, there are few data available on the association between SUA and hypertension; data from Bangladeshi adults are not available yet. This study evaluated the association of SUA with hypertension among Bangladeshi adults. Blood samples were obtained from 140 males and 115 females and analyzed for SUA and lipid levels. Hypertension was defined as SBP ≥ 140 mmHg and/or DBP ≥ 90 mmHg. All participants were divided into four quartiles based on SUA concentrations. Association of SUA with hypertension was evaluated by logistic regression models. The prevalence of hypertension and prehypertension was significantly higher in male (15.4 and 47.6%, respectively) than in the female (5.6 and 33.4%, respectively) subjects (p < 0.01). Males had a higher mean level of SUA (310.7 ± 67.9 µmol/L) than in the females (255.3 ± 69.3 µmol/L) (p < 0.001). Hyperuricemia was prevalent 9.1% in males and 10.3% in females. An increasing trend for hypertension and prehypertension was found in both genders with increasing SUA levels in the quartiles (p < 0.01). SUA levels in the quartiles were positively correlated with blood pressure (p < 0.01). After adjusting for baseline covariates, SUA levels were significantly associated with hypertension (p < 0.01). Findings of this study indicate the significance of maintaining normal SUA level to prevent hypertension.

Uric acid: from a biological advantage to a potential danger. A focus on cardiovascular effects

Non-communicable diseases represent nowadays the most common cause of death worldwide, having largely overcome infectious diseases. Among them, cardiovascular diseases constitute the majority. Given these premise, great efforts have been made by scientific societies to emphasize the fundamental role of cardiovascular prevention and risk factors control. In addition to classical cardiovascular risk factors such as smoking, arterial hypertension, hypercholesterolemia and male gender, new risk factors are emerging from international literature. Among them, uric acid is the protagonist. Several evidences show a direct role of hyperuricemia in the determinism of metabolic and vascular disorders. From the other hand, some researchers have demonstrated that uric acid is only a marker of cardiovascular damage and not a risk factor for its development. Aim of this review is to evaluate the scientific evidences on the role of uric acid in cardiovascular diseases in order to shed light on this confusing topic.

Impact of uric acid on incident hypertension: Sex-specific analysis in different age groups

The aim of the present study is to evaluate the association of serum uric acid (UA) levels with the risk of incident hypertension among different age groups in men and women using a single large Japanese general cohort. The present study is based on annual health check-up program in Gunma, Japan. We studied 12,029 participants (mean age, 48 ​± ​9 years old; 31% women) free of prevalent cardiovascular disease and hypertension at baseline (2009). Hypertension was defined by self-report, hypertensive medication use, or measured BP ​> ​140/90 ​mmHg ​at each visit. Discrete proportional hazards regression model was used to evaluate the association of UA level at baseline with incident hypertension through 2012 adjusted for age, gender, baseline blood pressure, and other CVD risk factors among different age decade groups in men and women. During follow-up of 3 years, 12% of the cohort (n ​= ​1457) developed hypertension. UA was strongly associated with incident hypertension in the multivariable model in all participants. In age-stratified analysis, participants below 50 years of age in men had the significant association of UA with incident hypertension, whereas participants above 50 years did not. In women, participants above 40 years had the significant association, whereas participants below 40 years did not. The present data suggest that UA level is an independent predictor for incident hypertension among middle aged men below 50 years old and middle aged and the elderly women above 40 years.

Uric acid association with pulsatile and steady components of central and peripheral blood pressures

OBJECTIVE

Whether the cardiovascular risk attributed to elevated uric acid levels may be explained by changes in central and peripheral pulsatile and/or steady blood pressure (BP) components remains controversial.

METHODS

In a cross-sectional analysis of normotensive and untreated hypertensive participants of the CARTaGENE populational cohort, we examined the relationship between uric acid, and both pulsatile and steady components of peripheral and central BP, using sex-stratified linear regressions.

RESULTS

Of the 20 004 participants, 10 161 individuals without antihypertensive or uric acid-lowering drugs had valid pulse wave analysis and serum uric acid levels. In multivariate analysis, pulsatile components of BP were not associated with uric acid levels, whereas steady components [mean BP (MBP), peripheral and central DBP] were all associated with higher levels of uric acid levels in women and men (all P < 0.001). Furthermore, there was a gradual increase of central SBP (cSBP), DBP and MBP from the lowest to the highest quintiles of uric acid levels but not for MBP-adjusted cSBP. Peripheral and cSBP, which are aggregate measures of pulsatile and steady BP, were also associated with uric acid levels in women (β = 0.063 and 0.072, respectively, both P < 0.001) and men (β = 0.043 and 0.051, both P ≤ 0.003). After further adjustments for MBP to account for the concomitant increase in steady component of BP, SBPs were no longer associated with uric acid levels.

CONCLUSION

Serum uric acid levels appear to be associated with both central and peripheral steady but not pulsatile BP, regardless of sex.

Gender- and Age-Specific Differences in the Association of Hyperuricemia and Hypertension: A Cross-Sectional Study

OBJECTIVE

Both hyperuricemia and hypertension have important clinical implications, but their relationship in terms of gender and age is still a matter of debate. In this study, we aimed to explore gender- and age-specific differences in this association between hyperuricemia and hypertension in a Chinese population.

METHODS

A total of 78596 ostensibly healthy subjects (47781 men and 30815 women) were recruited. The association between hyperuricemia and hypertension was analyzed by multivariate logistic regression, and the analyses were stratified by gender and age.

RESULTS

Overall prevalence of hypertension and hyperuricemia was significantly higher in males than in females. Increasing trends of hypertension prevalence in both genders as well as hyperuricemia prevalence in females were found along with aging. However, males showed a reduced trend in hyperuricemia prevalence with aging. Higher hypertension and hyperuricemia prevalence was found in young and middle-aged men than in women, but not in elderly people older than 70 years. Significantly increased risk of hypertension from hyperuricemia was found only in men with an adjusted odds ratio of 1.131 (P < 0.01), especially in the middle-aged male participants. However, such significant results were not found in women. Similarly, hyperuricemia was also an independent risk factor of increased systolic blood pressure and diastolic blood pressure in males, but not in females.

CONCLUSION

We observed significantly higher overall prevalence of hyperuricemia and hypertension in men than in women. Men with hyperuricemia (particularly in middle age) had a significantly increased susceptibility of hypertension, while this significant association was not observed in women.

Uric acid and angiotensin II additively promote inflammation and oxidative stress in human proximal tubule cells by activation of toll-like receptor 4

Renal proximal tubular cells (PTECs) participate in several mechanisms of innate immunity, express toll-like receptors (TLRs), and proinflammatory cytokines. Hyperuricemia may be a promoter of inflammation and renal damage. Angiotensin II (Ang II) modulate immune and inflammatory responses in renal tubular cells. With the aim to evaluate the effect of uric acid (UA) and Ang II on oxidative stress and inflammation mediated by toll-like receptor 4 (TLR4) activation in human PTECs, human kidney 2 (HK2) were incubated for 24 hr with UA (12 mg/dl) and Ang II (10 ^-7  M). HK2 were pretreated with an antagonist of TLR4 (TAK 242), valsartan or losartan. The genic expression of TLR4, monocyte chemoattractant protein-1 (MCP1), and Nox4 was quantified with reverse transcription polymerase chain reaction, proteins were evaluated with Western blot. The incubation of HK2 either with UA or with Ang II determines an increased expression of TLR4, production of proinflammatory cytokines as MCP1 and pro-oxidants as Nox4 ( p < 0.05). TAK 242 attenuates the expression of MCP1 induced both by UA and Ang II. Valsartan attenuated all the effects we described after exposure to Ang II but not those observed after UA exposure. At variance, pretreatment with losartan, which inhibits UA internalization, attenuates the expression of TLR4, MCP1, and Nox4 in cells previously treated with UA, Ang II, and UA plus Ang II. Proinflammatory pathways are induced in an additive manner by UA and Ang II ( p < 0.05) and might be mediated by TLR4 in PTECs. Renin-angiotensin-aldosterone system (RAAS) activation, hyperuricemia, and innate immunity interplay in the development of chronic tubular damage and the interaction of several nephrotoxic mechanisms blunt the protective effect of RAAS inhibition.

Dissociation between urate and blood pressure in mice and in people with early Parkinson's disease

Background

Epidemiological, laboratory and clinical studies have established an association between elevated urate and high blood pressure (BP). However, the inference of causality remains controversial. A naturally occurring antioxidant, urate may also be neuroprotective, and urate-elevating treatment with its precursor inosine is currently under clinical development as a potential disease-modifying strategy for Parkinson's disease (PD).

Methods

Our study takes advantage of a recently completed phase II trial evaluating oral inosine in de novo non-disabling early PD with no major cardiovascular and nephrological conditions, and of three lines of genetically engineered mice: urate oxidase (UOx) global knockout (gKO), conditional KO (cKO), and transgenic (Tg) mice with markedly elevated, mildly elevated, and substantially reduced serum urate, respectively, to systematically investigate effects of urate-modifying manipulation on BP.

Findings

Among clinical trial participants, change in serum urate but not changes in systolic, diastolic and orthostatic BP differed by treatment group. There was no positive correlation between urate elevations and changes in systolic, diastolic and orthostatic BP ((p = .05 (in inverse direction), 0.30 and 0.63, respectively)). Between UOx gKO, cKO, or Tg mice and their respective wildtype littermates there were no significant differences in systolic or diastolic BP or in their responses to BP-regulating interventions.

Interpretation

Our complementary preclinical and human studies of urate modulation in animal models and in generally healthy early PD do not support a hypertensive effect of urate elevation or an association between urate and BP.

Fund

U.S. Department of Defense, RJG Foundation, Michael J. Fox Foundation LEAPS program, National Institutes of Health, American Federation for Aging Research, Parkinson's Disease Foundation Advancing Parkinson's Therapies initiative.

Serum uric acid and arterial hypertension-Data from Sephar III survey

Objectives

This paper aims to evaluate the association between serum uric acid (SUA) levels, arterial hypertension (HT) prevalence, blood pressure values control, kidney function and intima media thickness (IMT), as a surrogate marker of early atherosclerosis, in a representative group of Romanian adult population.

Materials and methods

The study sample consists in 1920 adults included in SEPHAR III (Study for the Evaluation of Prevalence of Hypertension and cArdiovascular Risk in Romania) survey (mean age 48.63 years, 52.76% females) collecting data for SUA levels, blood pressure (BP) measurements, kidney function by estimated glomerular filtration rate (eGFR) and carotid IMT. SUA levels between 2,40–5,70mg/dl in females and 3,40–7,00mg/dl in males respectively were considered normal. HT and HT control were defined according to the current guidelines. IMT evaluation was assessed by B-mode Doppler ultrasound evaluation.

Results

Hypertensive subjects had significantly higher values of SUA compared with normotensive subjects, hypertensive patients were 1.713 times more likely to have higher values of SUA. Among treated hypertensive patients, those without optimal BP control had significantly higher SUA levels compared with those with optimal BP control, the presence of hyperuricemia increasing the odds of suboptimal BP control by 1.023. Hyperuricemic subjects had significantly lower eGFR values compared with normouricemic ones, on an average with 14.28ml/min/1.73m2 by Modification of Diet in Renal Disease formula (MDRD) and with 16.64ml/min/1.73m2 by Chronic Kidney Disease Epidemiology Collaboration formula (CKD-EPI), with an indirect association between SUA levels and eGFR values (rs = -0.319 / -0.347), independent of age. IMT values recorded in hyperuricemic subjects were significantly increased, on an average with 0.08mm, compared with normouricemic subjects, with a direct association between SUA levels and IMT values (rs = 0.263), independent of BP values.

Conclusion

The results of our study offers support that increased SUA levels are associated with arterial hypertension and with suboptimal BP control in treated hypertensive subjects. The decline in kidney function, independent of age, and also increased IMT values as a marker of atherosclerosis, were also correlated with elevated SUA values. Hyperuricemia screening may have a role in identifying patients at risk of developing HT and lowering SUA levels may improve not only BP control in treated HT patients but also decrease total cardiovascular mortality by slowing the progression of atherosclerosis and renal failure in hypertensive patients.

Management of hyperuricemia and gout in obese patients undergoing bariatric surgery

BACKGROUND

Hyperuricemia and gout represent important issues in the obese patients. Considering the epidemic trend of overweight and obesity in developed countries, the impact of these conditions is likely to increase. At present, bariatric surgery represents the most effective treatment for the management of severe obesity for reducing weight and the impact of associated comorbidities, but its effects on hyperuricemia and gout have not been fully elucidated.

METHODS

In this narrative review, we discuss the current knowledge about hyperuricemia and gout in obese patients undergoing bariatric surgery. We also suggest a useful approach to prevent gouty attacks in the perioperative period.

RESULTS

Weight loss seems to reduce hyperuricemia in the long-term follow-up, but there is evidence also of a high frequency of acute attacks early after surgery in patients with a diagnosis of gout.

CONCLUSION

Bariatric surgery has a high impact on hyperuricemia and gout. A perioperative approach is suggested, based on appropriate hydration, early physical resumption, urate lowering drugs and nonsteroidal anti-inflammatory drugs (NSAIDs), or colchicine and corticosteroids if NSAIDs are ineffective or not tolerated.

Interaction between body mass index and serum uric acid in relation to blood pressure in community-dwelling Japanese men

Background

Few data is available on the association between body mass index (BMI), serum uric acid (SUA) levels and blood pressure (BP) categories in the disease continuum, when efforts for its prevention may be applicable.

Methods

We performed a cross-sectional study to examine the association between BMI, SUA and BP in a community-dwelling sample of Japanese men. Individuals not on antihypertensive and uric acid lowering medications, and aged 50 to 90 years [817men aged 66 ± 9 (mean ± standard deviation) years] were recruited for the survey during a community based annual medical check-up. The main outcome was the presence of prehypertension [systolic BP (SBP) 120-139 mmHg and/or diastolic BP (DBP) 80-89 mmHg] and hypertension [SBP ≥ 140 and /or DBP ≥ 90].

Results

In participants with a BMI of < 21.0 kg/m², increased SUA levels were positively associated with SBP and DBP, but in those with a BMI of ≥ 21.0 kg/m², increased SUA levels were negatively associated with SBP and DBP. The interaction between BMI and SUA as well as BMI and SUA was a significant and independent determinant for both SBP (β = − 1.125, p = 0.001) and DBP (β = − 0.995, p = 0.005). Among participants, the respective prevalence of normotension, prehypertension, and hypertension was 19.5% and 53.7%, and 19.8%. The prevalence of normotension and prehypertension decreased with increasing BMI and the prevalence of hypertension increased with increasing BMI. In participants with a BMI ≥ 21.0 kg/m², the adjusted-odds ratio of SUA for hypertension was 0.75 (95% CI, 0.59-0.95) compared with normotension and 0.82 (0.70-0.96) compared with prehypertension. In those with a BMI of < 21.0 kg/m², these associations were not shown.

Conclusion

BMI may modify the association between SUA and blood pressure status among community-dwelling men.

Uric Acid Is a Strong Risk Marker for Developing Hypertension From Prehypertension: A 5-Year Japanese Cohort Study

Prehypertension frequently progresses to hypertension, a condition associated with high morbidity and mortality from cardiovascular diseases and stroke. However, the risk factors for developing hypertension from prehypertension remain poorly understood. We conducted a retrospective cohort study using the data from 3584 prehypertensive Japanese adults (52.1±11.0 years, 2081 men) found to be prehypertensive in 2004 and reexamined in 2009. We calculated the cumulative incidences of hypertension over 5 years, examined risk factors, and calculated odds ratios (ORs) for developing hypertension after adjustments for age, sex, body mass index, smoking and drinking habits, baseline systolic and diastolic blood pressure, pulse rate, diabetes mellitus, dyslipidemia, chronic kidney disease, and serum uric acid levels. The additional analysis evaluated whether serum uric acid (hyperuricemia) constituted an independent risk factor for developing hypertension. The cumulative incidence of hypertension from prehypertension over 5 years was 25.3%. There were no significant differences between women and men (24.4% versus 26.0%; P=0.28). The cumulative incidence of hypertension in subjects with hyperuricemia (n=726) was significantly higher than those without hyperuricemia (n=2858; 30.7% versus 24.0%; P<0.001). After multivariable adjustments, the risk factors for developing hypertension from prehypertension were age (OR, 1.023; P<0.001), female sex (OR, 1.595; P<0.001), higher body mass index (OR, 1.051; P<0.001), higher baseline systolic (OR, 1.072; P<0.001) and diastolic blood pressure (OR, 1.085; P<0.001), and higher serum uric acid (OR, 1.149; P<0.001). Increased serum uric acid is a strong risk marker for developing hypertension from prehypertension. Further studies are needed to determine whether treatment of hyperuricemia in prehypertensive subjects could impede the onset of hypertension.

The association between serum uric acid and blood pressure in different age groups in a healthy Chinese cohort

High serum uric acid (sUA) has been reported to be a risk factor for hypertension however, whether this is the case for all age groups is not clear. We examined the association between sUA concentrations and systolic and diastolic blood pressure (SBP and DBP) in different age groups in a cohort of healthy Chinese participants.A total of 1082 healthy participants aged from 41 to 70 years were included. sUA concentration was measured by the uricase-peroxidase method. SBP and DBP were assessed using mercury sphygmomanometry. Hypertension was defined as SBP ≥140 mm Hg or DBP ≥90 mm Hg. Hyperuricemia (HUA) was defined as sUA concentration of >7 mg/dL in men and >6 mg/dL in women. The association between sUA concentration and SBP and DBP was examined using Pearson's correlation test, multivariate linear regression, and logistic regression analysis.The prevalence of hypertension and HUA increased with age (P < .001). Hypertension was more common in participants that had HUA than in those that did not (38.95% vs 30.16%, P = .02). Higher sUA was significantly associated with higher SBP and DBP in the 41- to 50-year-old participants (SBP, β = 0.35, P < .001; DBP, β = .29, P < .001; after adjustment for age, sex, total cholesterol, estimated glomerular filtration rate, and fasting plasma glucose). HUA was also a risk factor for hypertension in this age group (odds ratio 1.425, 95% confidence interval, 1.217-1.668, P < .001). There was no association between sUA concentration and SBP and DBP in the other age groups.In this population of healthy Chinese participants, sUA concentration was positively associated with hypertension only in the 41- to 50-year-old group. Lowering uric acid in this age group may help to reduce the incidence of hypertension.

Salivary uric acid and C-reactive protein associations with hypertension in Midwestern Latino preadolescents and their parents

Latino families face increased risk for hypertension. Serum-based uric acid and C-reactive protein have been linked to hypertension. However, a paucity of salivary biomarker data exists in this area for Latino families. Using salivary biomarkers enables less invasive options for biomedical and biosocial research, which is especially important among vulnerable populations facing increased health disparities. This study examined the associations between salivary uric (sUA) acid, salivary C-reactive protein (sCRP), and hypertension among 151 participants (57 children, 57 mothers, 37 fathers) from 57 Midwestern Latino families. Participants self-administered the salivary samples, and blood pressure was measured by researchers. Results showed sUA was associated across family members, and child hypertension was related to parents' hypertension. sCRP was only related to sUA in fathers. Findings highlight the family-level health connections, along with the importance for further investigations using salivary biomarkers with Latinos, and the need for a robust sUA cut-off for hyperuricemia.

Uric acid in the pathogenesis of metabolic, renal, and cardiovascular diseases: A review

The association between uric acid (UA) on one side and systemic hypertension (Htn), dyslipidemia, glucose intolerance, overweight, fatty liver, renal disease and cardiovascular disease (CVD) on the other side is well recognized. However, the causal relationship between UA and these different clinical problems is still debatable. The recent years have witnessed hundreds of experimental and clinical trials that favored the opinion that UA is a probable player in the pathogenesis of these disease entities. These studies disclosed the strong association between hyperuricemia and metabolic syndrome (MS), obesity, Htn, type 2 diabetes mellitus (DM), non-alcoholic fatty liver disease, hypertriglyceridemia, acute kidney injury, chronic kidney disease (CKD), coronary heart disease (CHD), heart failure and increased mortality among cardiac and CKD patients. The association between UA and nephrolithiasis or preeclampsia is a non-debatable association. Recent experimental trials have disclosed different changes in enzyme activities induced by UA. Nitric oxide (NO) synthase, adenosine monophosphate kinase (AMPK), adenosine monophosphate dehydrogenase (AMPD), and nicotinamide adenine dinucleotide phosphate (NADPH)-oxidase are affected by UA. These changes in enzymatic activities can lead to the observed biochemical and pathological changes associated with UA. The recent experimental, clinical, interventional, and epidemiologic trials favor the concept of a causative role of UA in the pathogenesis of MS, renal, and CVDs.

Diet-independent relevance of serum uric acid for blood pressure in a representative population sample

A direct relationship between serum uric acid and blood pressure (BP) has been reported, but the possible confounding impact of diet on this association is unclear. The authors performed a cross-sectional analysis in the representative German Health Interview and Examination Survey for Adults (n=6788, aged 18-79 years). In adjusted regression models considering dietary factors, each 1-mg/dL higher uric acid value was associated with a 1.10-mm Hg (P=.0002) and a 0.60-mm Hg (P=.04) higher systolic BP among participants younger than 50 years and participants 50 years and older, respectively. For diastolic BP, uric acid was a significant predictor (β=0.71 mm Hg, P=.0001) among participants younger than 50 years and for participants 50 years and older without antihypertensive treatment. Adjusted odds ratios of hypertension for participants with hyperuricemia were broadly similar in younger (odds ratio, 1.71; P=.02) and older (odds ratio, 1.81; P=.0003) participants. Uric acid is a significant predictor of systolic BP and hypertension prevalence in the general adult population in Germany independently of several known dietary BP influences.

An observational study on the relationship between serum uric acid and hypertension in a Northern Chinese population aged 45 to 59 years

Little is known about the relationship serum uric acid (SUA) and hypertension in Chinese population. Therefore, the aim of this study was to determine the association between SUA and hypertension in a northern Chinese population. The participants were a group of 1730 Chinese adults aged 45 to 59 years in Shandong Province, who were recruited from the Linyi Nutrition and Health Survey (2015-2016). Hypertension was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. Hyperuricemia was defined as SUA >420 μmol/L (7.0 mg/dL) for men and >360 μmol/L (6.0 mg/dL) for women. All anthropometric measurements and biochemical data were collected following standard protocols. Multivariate logistic regression analysis was used to examine the association between SUA and hypertension with adjustment of confounding variables. Body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, fasting blood glucose, triglycerides, alanine aminotransferase, aspartate aminotransferase, SUA, and the prevalence of hypertension and hyperuricemia were significantly higher in males than in females (P < .001). The females had significantly higher levels of total cholesterol and high-density lipoprotein cholesterol. Besides, after adjustment for confounding variables, hyperuricemia was associated with an increased risk of hypertension in both male and female patients, with odds ratios of 2.152 (95% confidence interval 1.324-3.498) and 2.133(95% confidence interval 1.409-3.229), respectively.Hyperuricemia was significantly associated with the risk of hypertension. Further longitudinal studies and trails are needed to confirm our findings.

Baseline and Change in Uric Acid Concentration Over Time Are Associated With Incident Hypertension in Large Korean Cohort

BACKGROUND

It is uncertain whether high-baseline uric acid (UA) or change in UA concentration over time is related to development of incident hypertension. To investigate relationships between: (i) baseline serum UA concentration and (ii) change in UA concentration and incident hypertension.

METHODS

About 96,606 Korean individuals (with follow-up UA data available for 56,085 people) participating in a health check program was undertaken. Cox regression models were used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incident hypertension according to UA quartiles regarding the lowest UA quartile as the reference, and also according to change in UA concentration comparing individuals with an increase in UA to those with a decrease in UA concentration over time.

RESULTS

Total follow up time was 8 years (median follow-up 3.3 years; interquartile range, 1.9-5.1). About 10,405 cases of incident hypertension occurred. In the fully adjusted regression models, the HRs (95% CI) for incident hypertension comparing the highest vs. the lowest quartiles of UA were 1.29 (1.19-1.38) in men and 1.24 (1.09-1.42) in women, with statistically significant P for trend for both gender. Additionally, stable or increasing UA concentration over time was associated with increased risk of incident hypertension, particularly in participants with baseline UA concentration ≥median (aHRs 1.14; 95% CI (1.03-1.26) and 1.18; 95% CI (0.98-1.40) in men and women, respectively).

CONCLUSIONS

High initial UA concentration and increases in UA concentration over time should be considered independent risk factors for hypertension.

Asymptomatic hyperuricemia is a strong risk factor for resistant hypertension in elderly subjects from general population

OBJECTIVE

In clinical practice, patient characteristics predicting resistant hypertension (RH) include higher blood pressure levels, left ventricular hypertrophy, older age, obesity, chronic kidney disease and diabetes. On the contrary little is known about the role of serum uric acid (SUA) as a risk factor for RH in subjects from general population.

MATERIAL AND METHODS

580 elderly subjects aged ≥65 years were enrolled in the Risk Of Vascular complications Impact of Genetics in Old people (ROVIGO) study. RH was defined as the failure to maintain blood pressure values below 140mmHg (systolic) and 90mmHg (diastolic) despite therapeutic interventions that include appropriate lifestyle measures plus adherence to treatment with full doses of at least three antihypertensive drugs, including a diuretic. RH was confirmed using 24-h ambulatory blood pressure measurement. Hyperuricemic was defined as the subjects having SUA ≥6.8mg/dl or taking uricosuric drugs. Gender-specific odds ratio (OR) for RH was calculated by logistic regression analysis.

RESULTS

The prevalence of RH was 5.7% in the cohort and was higher in women (8.3%) than in men (3.0%, p<0.05). Independent of chronic kidney disease (OR 3.89, 95% confidence interval 1.49-10.1), hyperuricemia predicted resistant hypertension in women (odds ratio 3.11, 95% confidence intervals 1.06-9.1, p=0.03) but not in men.

CONCLUSIONS

In elderly women from the general population, an SUA value of ≥6.8mg/dl triples the risk of RH. SUA assessment should be recommended to better define the pattern of risk associated with RH.