Lowest Uric Acid Quartile Research Articles

Association of serum uric acid levels with benign prostatic hyperplasia in US men: results from NHANES 2005–2008

Background The relationship between uric acid (UA) and benign prostatic hyperplasia (BPH) is controversial and has rarely been studied in American populations. Methods Data from two cycles of the National Health and Nutrition Examination Surveys, comprising data from 2005 to 2008, were used. The majority of BPH were identified by self-report. We investigated the relationship between UA and BPH using univariate and multivariate logistic regression analyses. Results 2,845 participants were enrolled in the study, including 531 participants with BPH and 2,314 controls. After fully adjusting for all confounders, the risk of developing BPH was reduced by 18% for every 100 μmol/L increase in UA (OR = 0.82, 95% CI: 0.69–0.97, p = 0.023). Participants in the highest quartile of UA were found to have a reduced likelihood of developing BPH (ORQ4vs1 = 0.61, 95% CI: 0.41–0.91) in comparison to those in the lowest quartile of UA. Subgroup analyses found that among those younger than 60 years, non-Hispanic whites, former smokers, heavy drinkers, those without diabetes, or those with hypertension, high UA remained negatively associated with BPH. Conclusions The above results suggest that UA may be a potential protective factor for BPH, but the mechanism needs to be further explored.

Elevated Uric Acid Is Associated With New-Onset Atrial Fibrillation: Results From the Swedish AMORIS Cohort.

Background The role of uric acid is gaining increasing importance in the evaluation of cardiovascular disease, but its relationship with atrial fibrillation (AF) is unclear. This study aims to investigate the association between uric acid levels and risk of new-onset AF. Methods and Results A total of 339 604 individuals 30 to 60 years of age and free from cardiovascular disease at baseline (1985-1996) in the Swedish AMORIS (Apolipoprotein-Mortality Risk) cohort were followed until December 31, 2019 for incident AF. Cox regression models were used to examine the association between uric acid and AF, adjusting for potential confounders and stratifying by incident cardiovascular disease. Over a mean follow-up of 25.9 years, 46 516 incident AF cases occurred. Compared with the lowest uric acid quartile, each of the upper 3 quartiles were associated with an increased risk of AF in a dose-response manner. Adjusted hazard ratios were 1.09 (95% CI, 1.06-1.12) for second quartile, 1.19 (95% CI, 1.16-1.23) for third quartile, and 1.45 (95% CI, 1.41-1.49) for fourth quartile. The association was similar among individuals with and without incident hypertension, diabetes, heart failure, or coronary heart disease. The dose-response pattern was further supported in a subsample of individuals with repeated measurements of uric acid. Conclusions Elevated uric acid was associated with an increased risk of AF, not only among people with cardiovascular disease and cardiovascular risk factors but also among those without. Future investigations are needed to examine whether lowering uric acid is relevant for AF prevention.

Dose-Response Relationship of Uric Acid With Fasting Glucose, Insulin, and Insulin Resistance in a United States Cohort of 5,148 Non-diabetic People.

BackgroundThere is a limited number of studies on the dose-response relationship between serum uric acid and impaired glucose metabolism in people without diabetes, and no large-scale research exploring the relationship in women without diabetes is based on menopausal status. Consequently, the present study aimed to investigate the above relationship in United States adults without diabetes.Materials and MethodsData from 2,498 men and 2,650 women aged ≥20 years were obtained from the National Health and Nutrition Examination Survey 2011–2016 conducted in the United States. Binary logistic regression analysis was applied to evaluate the association between uric acid and impaired glucose metabolism. Restricted cubic spline analysis, sensitivity analysis, and stratified analysis by menopausal status were performed to explore the above relationships.ResultsA positive correlation was found between uric acid and the risk of insulin resistance in all participants (P < 0.05). In binary logistic regression analysis, after adjusting for confounding factors, compared with the lowest quartile of uric acid, the odds ratio (95% confidence intervals) of insulin resistance in the highest quartile was 1.9 (1.1–3.1) and 2.2 (1.2–4.3) in men and women, respectively. A significant positive relationship was also observed between uric acid and impaired fasting glucose and hyperinsulinemia in women, while in men, uric acid was positively associated with the risk of hyperinsulinemia but not impaired fasting glucose. Restricted cubic spline showed that the odds ratios of insulin resistance and hyperinsulinemia increased with elevating uric acid levels in both men and women. When stratified by menopause, the association remained significant in pre-menopausal women aged ≥20, but insignificant in post-menopausal women.ConclusionUric acid was positively associated with the risk of impaired glucose metabolism in a cohort of United States adults, and uric acid increased the risk of insulin resistance in pre-menopausal, but not in post-menopausal women.

Association of blood uric acid and cognitive impairment in oldest-old aged 80 years and older in 9 longevity areas of China

Objective: To examine the association of blood uric acid (UA) and cognitive impairment (CI) among oldest-old adults in China. Methods: Data was collected in 9 longevity areas of China from Healthy Aging and Biomarkers Cohort Study (HABCS) conducted during 2017-2018. Finally,1, 622 elderly aged 80 years and older with complete information on blood UA and cognitive function score were included in this study. Information on demographic characteristics, lifestyle, and health status were collected through questionnaire and physical examination. Venous blood samples of the participants were collected to test blood UA level. Cognitive impairment (CI) was assessed using the Chinese Mini-Mental State Examination (MMSE) according to personal educational level. Generalized Estimating Equations (GEE) model for binary data was used to analyze the association of blood UA and CI, and further compared the associations among different age and body mass index (BMI) groups. Results: Of the 1 622 oldest-old, the mean age was (92.2±8.1) years, 656 (40.4%) were male, the mean level of blood UA was (343.3±86.2) μmol/L, and 482 (29.7%) oldest-old had CI. Compared with the lowest quartile of UA, the risks of CI in the second, third and highest quartiles were gradually reduced, the corresponding ORs and 95%CI were 0.99 (0.71-1.33), 0.87 (0.68-0.94) and 0.69 (0.48-0.85), respectively; and the linear trend test was statistically significant (P<0.001). Subgroup analysis showed that the effects of higher UA associated with lower risk of CI were stronger in younger oldest-old (aged 80-89 years) and thinner group (BMI<24) (Pinteraction<0.05). Conclusions: Blood UA was negatively associated with the risk of having CI in the oldest-old among the nine longevity areas of China.

Serum uric acid levels and risk of kidney cancer incidence and mortality: A prospective cohort study.

ObjectiveEpidemiological evidence investigating serum uric acid and kidney cancer risk remains unclear. We conducted this study to examine the relationship between serum uric acid and the incidence and mortality of kidney cancer.MethodsThis is a prospective analysis of 444 462 participants without any cancer from the UK Biobank. Serum uric acid was measured at baseline and the incidence and mortality of kidney cancer was determined through contact with the cancer and death registry. Cox regression models were fitted to estimate the hazard ratio (HR) and 95% confidence interval (95%CI), adjusting for demography, lifestyle style, comorbidities, and medication use.ResultsWe documented 638 incidence cases and 188 mortality cases of kidney cancer over a median of 6.5 years follow‐up. People with the highest quartile had a 45% increased risk of kidney cancer compared to those with the lowest uric acid quartile (HR 1.45, 95%CI 1.08 to 1.93). Subgroup analyses showed that serum uric acid was associated with cancer risk among females but not among males (Q1 vs Q4: females HR1.47, 95%CI 1.01 to 2.16; males HR 1.19, 95%CI 0.91 to 1.56). Although we found serum uric acid was associated with an increased risk of kidney cancer mortality in age‐stratified model (HR 2.49, 95% CI 1.61 to 3.84), this association disappeared after further adjustment for other confounders.ConclusionsHigh uric acid is associated with a high incidence of kidney cancer, especially in women. More research is needed to confirm our findings.

Serum Uric Acid is Associated with the Predicted Risk of Prevalent Cardiovascular Disease in a Community-dwelling Population without Diabetes

ObjectiveTo examine the association between serum uric acid levels and cardiovascular disease risk among individuals without diabetes. MethodsWe investigated the association between serum uric acid levels and the risk of prevalent cardiometabolic diseases, 10-year Framingham risk for coronary heart disease, and 10-year risk for atherosclerotic cardiovascular diseases (ASCVD) among 8,252 participants aged ≥ 40 years without diabetes from Jiading district, Shanghai, China. ResultsBody mass index, waist circumference, blood glucose, glycated hemoglobin, blood pressure, and serum lipids increased progressively across the sex-specific quartiles of uric acid (all P trend < 0.05). Compared with individuals in the lowest quartile, those in the higher quartiles had a significantly higher prevalence of obesity, hypertension, and dyslipidemia (all P trend < 0.05). A fully adjusted logistic regression analysis revealed that individuals in the highest quartile had an increased risk of predicted cardiovascular disease compared with those in the lowest quartile of uric acid. The multivariate adjusted odds ratios (ORs) [95% confidence intervals (CIs)] for the highest quartiles for high Framingham risk were 3.00 (2.00–4.50) in men and 2.95 (1.08–8.43) in women. The multivariate adjusted ORs (95% CIs) for the highest quartile for high ASCVD risk were 1.93 (1.17–3.17) in men and 4.53 (2.57–7.98) in women. ConclusionSerum uric acid level is associated with an increased risk of prevalent obesity, hypertension, dyslipidemia, 10-year Framingham risk for coronary heart disease, and 10-year risk for ASCVD among Chinese adults without diabetes.

Uric acid and incident chronic kidney disease in dyslipidemic individuals

Background: Elevated uric acid (UA) is a recognized risk factor for chronic kidney disease (CKD). This study aimed to investigate whether this association exists in dyslipidemic patients receiving multifactorial treatment. Methods: An observational study conducted in Greece including 1,269 dyslipidemic individuals followed-up in a lipid clinic for ≥3 years. Estimated glomerular filtration rate (eGFR) was calculated by CKD-EPI equation and CKD was defined as ≤60 mL/min/1.73 m2. The correlation was assessed between UA levels and the CKD risk after adjusting for potential confounding factors, after defining the following UA quartiles: Q1: < 4, Q2: 4–5, Q3: 5–6, and Q4: > 6 mg/dL. Results: After excluding patients with baseline eGFR <60 mL/min/1.73 m2, gout and those taking UA-lowering drugs, 1,095 individuals were eligible; of those, 91% and 69% were treated with statins and anti-hypertensive drugs, respectively. During their follow-up (6 years; IQR = 4–10), 11.9% of the subjects developed CKD, whereas the median annual eGFR decline was 0.69 mL/min/1.73 m2 (IQR = 0.45–2.33). Multivariate analysis showed that baseline UA levels (HR = 1.26; 95% CI = 1.09–1.45, p = .001), female gender (HR = 1.74; 95% CI = 1.14–2.65, p = .01), age (HR = 1.10; 95% CI = 1.07–1.12, p < .001), diabetes (HR = 1.67; 95% CI = 1.05–2.65, p = .03), cardiovascular disease (HR = 1.62; 95% CI = 1.02–2.58, p = .04), decreased baseline renal function (eGFR <90 mL/min/1.73 m2) (HR = 2.38; 95% CI = 1.14–4.81, p = .02), and low-density lipoprotein cholesterol reduction (HR = 0.995; 95% CI = 0.991–0.998, p = .01) were associated with incident CKD. Additionally, patients with UA ≥6 mg/dL exhibited a higher risk of incident CKD compared with those in the lowest UA quartile (HR = 2.01; 95% CI = 1.11–3.65, p = .02). Conclusion: Higher UA levels are correlated with a higher risk of incident CKD in dyslipidemic individuals taking multifactorial treatment.

Serum uric acid concentration is associated with hypertensive retinopathy in hypertensive chinese adults

BackgroundThis cross sectional investigation included 12,966 subjects with hypertension, a cohort of the China Stroke Primary Prevention Trial (CSPPT), a randomized, multicenter clinical trial. This study aimed to explore the correlation between serum uric acid (SUA) concentration and hypertensive retinopathy in hypertensive adults.MethodsDiagnosis of hypertensive retinopathy was determined by non-mydriatic fundus photography and classified with Keith-Wagener-Barker (KWB) system. The correlation of SUA levels with hypertensive retinopathy prevalence and severity was assessed by statistical analysis.Results9848 (75.95%) subjects were diagnosed with hypertensive retinopathy with the following retinopathy grade distribution: grade 1: 58.80%, grade 2: 14.81%, and grade 3–4: 2.34%. SUA levels were significantly associated with hypertensive retinopathy prevalence. Patients with hypertensive retinopathy had higher SUA levels than those without hypertensive retinopathy. Patients in the highest uric acid quartile had an odds ratio for hypertensive retinopathy of 1.21 compared to patients in the lowest uric acid quartile (OR = 1.21, 95% CI: 1.05–1.40, P = 0.008). When compared to the non-hyperuricemia group, those in the hyperuricemia group had an odds ratio for hypertensive retinopathy of 1.18(OR = 1.18, 95% CI: 1.05–1.33, P = 0.004). Every 1 mg/dl increase in uric acid concentration was significantly associated with a 6% higher odds of hypertensive retinopathy (OR = 1.06, 95% CI: 1.02–1.10, P = 0.002).ConclusionsThe prevalence of hypertensive retinopathy was high (75.95%) among hypertensives in our patients cohort. In addition, SUA concentration was significantly associated with hypertensive retinopathy.

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

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

Elevated Serum Uric Acid Is Associated with Greater Bone Mineral Density and Skeletal Muscle Mass in Middle-Aged and Older Adults.

Background and objectivePrevious studies have suggested a positive link between serum uric acid (UA) and bone mineral density (BMD). In this study, we re-examined the association between UA and BMD and further explored whether this was mediated by skeletal muscle mass in a general Chinese population.MethodThis community-based cross-sectional study was conducted among 3079 (963 men and 2116 women) Chinese adults aged 40–75 years. Face-to-face interviews and laboratory analyses were performed to determine serum UA and various covariates. Dual-energy X-ray absorptiometry was used to assess the BMD and appendicular skeletal muscle mass. The skeletal muscle mass index (SMI = ASM/Height2, kg/m2) for the total limbs, arms, and legs was then calculated.ResultsThe serum UA was graded and, in general, was significantly and positively associated with the BMD and muscle mass, after adjustment for multiple covariates in the total sample. Compared with participants in lowest quartile of UA, those participants in highest quartile showed a 2.3%(whole body), 4.1%(lumbar spine), 2.4%(total hip), and 2.0% (femoral neck) greater BMDs. The mean SMIs in the highest (vs. lowest) quartile increased by 2.7% (total), 2.5% (arm), 2.7% (leg) respectively. In addition, path analysis suggested that the favorable association between UA and BMD might be mediated by increasing SMI.ConclusionThe elevated serum UA was associated with a higher BMD and a greater muscle mass in a middle-aged and elderly Chinese population and the UA-BMD association was partly mediated by muscle mass.

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

BackgroundA relationship of blood uric acid (UA) with hypertension and cardiovascular risk is under debate thus salt intake is hypothesized to contribute to such associations.MethodsIn this cross-sectional study, stratified cluster random sampling elicited a sample of 1805 Kazakhs with 92.4% compliance. Hypertension and moderate-or-high total cardiovascular risk (mTCR) were defined according to guidelines. Sodium intake was assessed by urinary sodium excretion. Prevalence ratios (PRs) were used to express associations of UA with hypertension and mTCR.ResultsIn the highest tertile of sodium intake in women, the adjusted PRs (95% confidence intervals) of low to high quartiles compared with the lowest quartile of UA, were 1.22(0.78–1.91), 1.18(0.75–1.85), and 1.65(1.09–2.51) for hypertension and 1.19(0.74–1.90), 1.39(0.91–2.11), and 1.65(1.10–2.47) for mTCR (P for trend <0.05). However, these findings were not shown for other sodium intake levels. There were similar results in men. PRs markedly increased with a concomitant increase in UA and sodium intake and there was a significant interaction (P = 0.010) for mTCR with PRs of 1.69(1.10–2.60) for men and 3.70(2.09–6.52) for women in those with the highest compared with the lowest quartile of UA and tertile of sodium intake. Similar findings were shown for hypertension.ConclusionsThis study implied that a high salt intake may enhance the associations of UA with hypertension and cardiovascular risk.

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

BackgroundIncreased levels of uric acid (UA) have been associated with cardiovascular disease. This association is generally stronger in women than men. However, gender differences in the prognostic value of UA in patients with acute coronary syndrome (ACS) are unknown. We investigated gender differences in the relationship between UA level and the prognosis in patients with ACS. MethodThis was an observational analysis of patients with ACS undergoing percutaneous coronary intervention enrolled in the Ibaraki Cardiac Assessment Study (ICAS) registry. We analyzed 1380 patients (330 women, 1050 men) with ACS who had information on UA. We assessed the association between UA and the incidence of major cardiovascular adverse events (MACE), defined as all-cause death, congestive heart failure, reinfarction, and stroke. Patients were divided according to gender-specific UA quartile. ResultsThe mean UA level in women was significantly lower than that in men (4.9mg/dl vs 5.9mg/dl, p<0.001). After a median duration of follow-up period of 437 days (interquartile range 222–801 days), MACE had occurred in 186 (13%) patients [56 (17%) events in women; 130 (12%) events in men]. Kaplan-Meier analysis for MACE-free survival demonstrated that a higher quartile of UA was associated with MACE in both women and men (p<0.001, p=0.002, respectively). Multivariate Cox regression analysis revealed that the highest quartile of UA, as compared with the lowest quartile of UA, was an independent predictor of MACE in women [hazard ratio (HR), 2.84; 95% CI, 1.19–6.77; p=0.018] but not in men (HR, 1.32; 95% CI, 0.66–2.64; p=0.422). ConclusionsAn increased level of UA was associated with MACE more strongly in women than in men with ACS. These results suggest that there are gender differences in the association of UA level with the prognosis in patients with ACS.

Plasma Uric Acid Is Associated with Increased Risk of Type 2 Diabetes Independent of Diet and Metabolic Risk Factors

Current evidence suggests a direct association of uric acid with diabetes risk, but it is still unclear whether this is independent of risk factors such as obesity and diet. We aimed to investigate whether plasma uric acid concentrations are independently associated with incident type 2 diabetes and to investigate the role of a uric acid–related dietary pattern in this association. We used a case-cohort nested in the European Prospective Investigation into Cancer and Nutrition-Netherlands study. The study included 2318 subcohort members and 845 incident diabetes cases, with a mean follow-up of 10 y. At baseline, blood samples were taken and diet was assessed using a validated FFQ. A uric acid–related dietary pattern was derived with reduced rank regression. Diabetes was mainly self-reported and verified against general practitioner records. Plasma uric acid was (mean ± SD) 231 ± 54.6 μmol/L in the subcohort. After adjustment for established diabetes risk factors such as age, the HR (highest vs. lowest quartile of uric acid) for diabetes was 4.36 (95% CI: 3.22, 5.90). Further adjustment for adiposity attenuated the HR to 1.86 (95% CI: 1.32, 2.62). Additional adjustment for hypertension and biochemical markers, such as TG, slightly attenuated the association [HR = 1.43 (95% CI: 0.97, 2.10)]. A uric acid–related dietary pattern did not confound the association. In conclusion, this study supports that high uric acid concentrations are associated with increased diabetes risk, although a large part of the association can be explained by the degree of adiposity.

Association of serum uric acid level with coronary artery lesion and metabolic syndrome

Objective To analyze the association of blood uric acid level with the severity of coronary artery stenotic changes, metabolic syndrome (MS), and its components. Methods A total of 343 individuals ( male 223,female 120) who underwent coronary angiography and had complete data on MS and serum uric acid were collected. The severity of coronary artery disease (CAD) was assessed by the coronary stenesis index (CSI). MS was diagnosed according to the Guideline on Prevention and Treatment of Blood Lipid Abnormality in Chinese Adults. Results (1)The mean uric acid level was significantly lower in women than in men [ ( 306.3±76.9 vs 358.9±85.2 ) μmol/L, P＜0.01 ]. The prevalence of MS and its components showed no difference between men and women. (2) The uric acid level in women with 3 components was higher than those with1( P＜0. 01 ) or 2 ( P＜0.05 ) components of metabolic disorders, but not in men. (3) Quartiles of concentration of uric acid were computed. Compared with those in the lowest quartile of uric acid, women in the highest quartile had higher CSI score [ 7.0 (2.5-12.0) vs 2. 0( 0.0-6.0), P= 0. 025 ]. Moreover, the uric acid level was higher in women with multivessel lesions than nonCAD patients [ (327.0±81.9 vs 284.9±78.6) μmol/L, P = 0.033 ]. However, no correlation was found between uric acid level and the severity of coronary artery lesion in men. (4) Logistic regression showed that age (β=0.042, P=0. 007) and dyslipidemia(β=0.836, P=0. 037 ) were the independent risk factors of CAD in men, and hypertension(β=1. 127, P=0.039) and dyslipidemia(β=0.901, P=0.009)in women. Conclusions In women with higher uric acid level, the clustering of metabolic abnormalities was increased, and the coronary artery lesion was more severe. High uric acid level might be a marker of CAD for women. Key words: Uric acid; Coronary artery disease; Coronary angiography; Metabolic syndrome

Serum uric acid and metabolic syndrome in Taiwanese adults

A positive association between serum uric acid and metabolic syndrome has been reported, but little information is available about the association between serum uric acid and metabolic syndrome in Taiwanese adults. The purpose of this study was to investigate the association between serum uric acid levels and metabolic syndrome in Taiwanese adults. We performed a cross-sectional study of 2085 men and 1557 women. All of the participants underwent a health screening during the period from January 2005 to December 2005 at a health center of the Shin Kong Wu Ho-Su Memorial Hospital. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. The results showed that hyperuricemia was significantly associated with increased risk for hypertriglyceridemia, low high-density lipoprotein cholesterol level, and high blood pressure in men and women. The risk of metabolic syndrome was significantly higher in the fourth quartile than in the first quartile of uric acid level in men (odds ratio [OR], 1.50; 95% confidence interval [CI], 1.06-2.14) and women (OR, 2.33; 95% CI, 1.39-3.93). In addition, uric acid level was inversely associated with hyperglycemia in men. The ORs of hyperglycemia for the second, third, and fourth quartile of uric acid were 0.69 (95% CI, 0.46-1.03), 0.55 (95% CI, 0.37-0.83), and 0.45 (95% CI, 0.29-0.69), respectively, compared with the lowest quartile of uric acid. The results demonstrate that there is a positive association between serum uric acid levels and metabolic syndrome and an inverse association between uric acid and fasting plasma glucose in Taiwanese adults.

Abstract 5414: Serum Uric Acid Levels versus the Abdominal Obesity in Relation to Incident Hypertension in a Prospective Study in a Chinese Community

BACKGROUND: Most Caucasian-based epidemiological data have shown that hyperuricemia is associated with the risk of hypertension, but whether this association is independent of adiposity and other vascular risk factors remains unclear. Therefore, we evaluated the associations of serum uric acid versus abdominal obesity with incident hypertension in a large Chinese Han population. METHODS: We conducted a community-based prospective cohort study comprising 7220 participants (mean age 37 years; 74% men) in the Qingdao Health and Nutrition Examination Survey in China, who were free from hypertension at study entry in 1999–2000. During 4-year follow-up, 1370 men (19.0%) and 208 women (11.0%) had developed hypertension. RESULTS: After adjustment for age, body mass index, waist circumference, and other covariates, the relative risks (RR) of developing hypertension according to uric acid quartiles were 0.97, 1.23, and 1.39 [95% confidence interval (CI), 1.16–1.68; P trend=0.008] for men and 1.49, 1.58, 1.85 (95%CI, 1.06–3.24; P trend=0.007) for women. The associations of hypertension with serum uric acid increased with the component number of metabolic syndrome (none, one, two, or more), which is defined by the criteria of the modified Adult Treatment Panel III and an Asian-specific waist circumference cut-off point (≥90 cm in men, ≥80 in women). Given that abdominal obesity is an important underlying risk factor for metabolic syndrome, in joint analyses of waist circumference and serum uric acid, participants with abdominal obesity had a consistently higher risk than those without. Compared with those in the lowest uric acid quartile and without abdominal obesity, participants who were in the highest quartile and also had abdominal obesity had a 3.0-fold and 3.4-fold greater risk of incident hypertension in men (95%CI, 1.56–2.97) and in women (95%CI, 2.10–3.81), respectively. To minimize the bias from reverse causality due to subclinical hypertension, analyses after excluding the first 2 years of follow-up showed similar results. CONCLUSIONS: These data suggest a positive association between serum uric acid and incident hypertension during short-term follow-up in a Chinese population. The association was partly mediated through abdominal obesity. 1

Plasma Uric Acid and Hypertension in a Chinese Community: Prospective Study and Metaanalysis

Hyperuricemia has been positively associated with hypertension, but whether this association is independent of adiposity and other cardiovascular risk factors remains a matter of debate. We conducted a community-based prospective cohort study comprising 7220 participants (mean age 37 years; 73.8% men) in the Qingdao Port Health and Nutrition Examination Survey in China, who were free from hypertension at study entry in 1999-2000. During 4-year follow-up, 1370 men (19.0%) and 208 women (11.0%) had developed hypertension. After adjustment for age, body mass index, and other covariates, the relative risks (RRs) of developing hypertension comparing the highest and lowest uric acid quartiles were 1.55 (95% CI 1.10-2.19; P for trend <0.001) for men and 1.91 (1.12-3.25; P for trend <0.001) for women. After additional adjustment for abdominal obesity, the RRs comparing the participants in the highest and lowest quartiles of uric acid were 1.39 (1.16-1.68; P for trend 0.003) for men and 1.85 (1.06-3.24; P for trend 0.006) for women. In joint analysis, compared with those in the lowest uric acid quartile and without abdominal obesity, participants who were in the highest quartile and also had abdominal obesity had a 3.0- and 3.4-fold greater risk of incident hypertension (1.56-3.97 for men and 2.10-3.81 for women, respectively). These data suggest a positive association between plasma uric acid and incidence of hypertension during short-term follow-up in a Chinese population. The association between hyperuricemia and hypertension was partly mediated by abdominal obesity.

Elevated Uric Acid Levels Predict Allograft Vasculopathy in Cardiac Transplant Recipients

Cardiac allograft vasculopathy (CAV) poses the greatest threat to the long-term survival of cardiac transplant recipients, and these individuals often exhibit elevated levels of uric acid (UA), a stimulator of T cells. We hypothesized that hyperuricemia is associated with CAV in cardiac transplant recipients. UA levels were measured in cardiac transplant recipients between January 2003 and January 2005. Surveillance cardiac catheterizations performed 3 months to 1 year after UA measurement were reviewed. The relationship between UA and CAV was adjusted for possible confounders with propensity scores and confirmed with goodness-of-fit tests. The 105 patients included in this study were a median 63.3 months post-transplant and their left heart catheterizations were performed a median 5.6 months after UA measurement. Focal stenosis was evident in 25 angiograms and 31 showed distal pruning of the coronary arteries. Compared with the lowest quartile of UA, the highest quartile had an increased risk of CAV: odds ratio (OR) 6.11 (95% CI 1.47 to 25.5; p = 0.013) for focal stenosis and OR 4.60 (95% CI 1.34 to 15.8; p = 0.015) for distal pruning. After adjustment, this relationship persisted for both focal stenosis (OR 5.53, 95% confidence interval [CI] 1.29 to 23.7; p = 0.021) and distal pruning (OR 4.21, 95% CI 1.15 to 15.4; p = 0.029). Elevated UA confers an increased risk of CAV. This association may be causal, with pathophysiologic implications for the role of hyperuricemia in allograft failure and, if substantiated, could have clinical implications for the use of xanthine oxidase inhibitors in cardiac transplant recipients.

Plasma Uric Acid Level and Risk for Incident Hypertension Among Men

Several studies have found that uric acid (UA) level is associated with an increased risk for hypertension, but the association could be confounded by metabolic factors that were not included in these previous studies. UA level and risk for incident hypertension was examined prospectively among men who participated in the Health Professionals' Follow-up Study. From among men without hypertension at the time blood was collected, 750 participants who developed hypertension during the subsequent 8 yr and 750 age-matched controls were selected. In addition to adjustment for standard hypertension risk factors and renal function, adjustments controlled for fasting insulin, triglyceride, and cholesterol levels. The mean age of participants was 61 yr, and mean plasma UA level was 6.0 mg/dl (SD 1.25 mg/dl). The multivariable relative risk (RR) for a 1-SD increase in UA was 1.02 (95% confidence interval [CI]0.87 to 1.18); the RR comparing the highest with lowest quartile of UA was 1.08 (95% CI 0.71 to 1.63). The multivariable RR associated with a 1-SD increase in UA was 1.38 (95% CI 1.05 to 1.81) for men aged <60 yr and 0.90 (95% CI 0.74 to 1.10) for men >or=60 yr (P = 0.04 for interaction). However, further adjustment for fasting insulin, triglyceride, and cholesterol levels attenuated the results (RR for men <60 yr 1.24; 95% CI 0.93 to 1.66). In conclusion, no independent association between UA level and risk for incident hypertension was found among older men.