Association Of Uric Acid Research Articles

The significance of uric acid in the diagnosis and treatment of Parkinson disease: An updated systemic review.

Background:Parkinson disease (PD) is a neurodegenerative disease characterized by chronic and progressive loss of dopaminergic neurons in substansia nigra pars compacta. Oxidative stress is proposed to play a critical role in the pathogenesis of PD. Uric acid (UA), as an important physiological antioxidant, is identified a molecular predictor associated with a decreased risk and a slower disease progression for PD and potential neuroprotectant of PD by increasing epidemiological and clinical evidences. Within this review, we will present a comprehensive overview of the data linking UA to PD in recent years.Methods:We searched PubMed, EMBASE, Web of Science databases for relevant studies. Any observational or experimental studies that evaluated UA and PD were our goal of searching the electric databases.Results:Twelve studies that evaluated UA and PD were identified in this review. We reviewed the roles of UA in the pathogenesis of PD, the association of UA with morbidity, severity/progression, nonmotor symptoms, motor complications of PD, with an attempt to provide new ideas for diagnosis and treatment in PD.Conclusion:Our findings supported that lots of clinical and epidemiological data observed lower UA levels in PD patients. Manipulation of UA or its precursors’ concentration could be effective to treat or prevent PD. However, it is still suspectable that higher UA levels are better enough to PD patients. Furthermore, for the complex nature of PD and its heterogeneous genetic and environmental influences, it is inadequate for just manipulating UA in treating the disease.

Abstract P516: Arterial Stiffness is a Mediator of Uric Acid-related Development of Hypertension

Objectives: Uric acid (UA) is a risk for the development of hypertension, but the underlying mechanisms of this development has not been fully clarified. On the other hand, arterial stiffness is also noted as a risk for the development of hypertension. Then, the present prospective observational study examined whether UA is associated with the development of hypertension mediated by the increase of arterial stiffness. Methods and Results: In 3274 middle-aged Japanese men (aged 42 ± 9 years old) without hypertension at the study baseline, the brachial-ankle pulse wave velocity (baPWV), radial augmentation index (rAI), systolic and diastolic blood pressure (SBP/DBP) and serum UA level were measured annually over a 9-year period. During this study period, 474 subjects (14.5%) developed hypertension. Binary logistic regression analysis demonstrated that serum UA levels has a significant odds ratio for the development of hypertension even after the adjustment [1.3 (1.1-1.5), p<0.01]. Multivariate linear regression analysis also demonstrated that serum UA levels at the baseline of study period had a significant association with delta changes of SBP (beta=0.10 p<0.01), DBP (beta = 0.13, p<0.01) and baPWV (beta=1.12 p<0.01), but not that of rAI, during the study period. Mixed model linear regression analysis in repeated measurement data revealed the following: 1) At each annual measurement, higher serum UA levels were associated with a higher annual increase of the SBP (estimate=0.63 p<0.01), DBP (estimate=0.63 p<0.01) and baPWV (estimate=6.70 p<0.01). Mediation analysis demonstrated that baPWV had a significant indirect effect on the association of UA at the baseline with the delta change of SBP (indirect effect = 0.03 p<0.01). Conclusion: UA is a risk for the development of hypertension. In there, UA may elevate blood pressure via increase in arterial stiffness, at least in parts.

Serum Uric Acid Relation for Hearing Threshold Shift.

Objectives The effects of serum uric acid (UA) level on a variety of diseases were found from experimental and observational studies via oxidative stress and anti-oxidants. However, research on the association of UA and hearing thresholds is relatively sparse. We investigated this issue in the U.S. general population to evaluate the relationship of serum UA levels and pure tone threshold of hearing.Methods Forty four thousand eighty four eligible participants aged 20 to 69 years who have serum UA data and received Audiometry Examination Component were enrolled from the National Health and Nutrition Examination Survey 1999–2004. Hearing thresholds (dB) as a pure tone average at low frequencies (0.5, 1, 2 kHz) and at high frequencies (3, 4, 6, and 8 kHz) were computed. Multivariate linear regression models and tertile-based analysis with an extended-model approach for covariates adjustment were used to assess the correlation between serum UA level and hearing thresholds.Results In the adjusted mode of tertile-based analysis, the regression coefficients elucidated as the change of log-transformed mean hearing thresholds upon comparing participants in the highest tertile of serum UA to those in the lowest tertile were –0.067 (P=0.023) in high frequency and –0.058 (P=0.054) in low frequency. After adjusting for multiple pertinent covariates, inverse association between tertiles of serum UA and hearing thresholds remained essentially unchanged. The negative trends between serum UA and hearing thresholds were statistically significant (P for trends <0.05) in tertile-based multiple linear regressions.Conclusion Individuals with elevated UA levels independently were found to be inversely associated with hearing thresholds for pure tone audiometry in a nationally representative sample of U.S. adults.

Hepatic, renal and inflammatory biomarkers are positively associated with blood pressure changes in healthy pregnant women: a prospective cohort.

This article evaluates the association of hepatic, renal, and inflammatory biomarkers with changes in systolic (SBP) and diastolic (DBP) blood pressure (BP) during healthy pregnancies.A prospective cohort study with 225 healthy pregnant women was conducted in Rio de Janeiro, Brazil. SBP and DBP were evaluated throughout pregnancy (5th–13th, 20th–26th, and 30th–36th gestational weeks) and were the outcomes. The following biomarkers were measured at the first trimester and analyzed according to tertiles of the sample distribution and were considered the main independent predictors: alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid (UA), creatinine (Cr), and C-reactive protein (CRP) concentrations. The statistical analysis included 3 stages of modeling with the longitudinal linear mixed-effects procedures: Model 1 was adjusted for gestational age and quadratic gestational age; Model 2 included interactions between the biomarkers and gestational age; and Model 3 was adjusted for self-reported skin color, education, parity, early-pregnancy body mass index (BMI) (under/normal <25; overweight/obese ≥25 kg/m2), smoking habit, and leisure-time physical activity. Additional models were performed for CRP and UA with the inclusion of interaction terms between the biomarkers and BMI.Women classified in the third tertile of the ALP (≥61.1 U/L; βSBP = 3.474; 95% confidence interval [CI]: 0.955–5.992; βDBP = 3.291; 95% CI: 1.098–5.485), ALT (≥14.3 U/L; βSBP = 2.232; 95% CI: 0.221–4.242; βDBP = 2.355; 95% CI: 0.721–3.989), and Cr values (≥48.6 μmol/L; βDBP = 1.927; 95% CI: 0.347–3.508) presented higher BP levels during pregnancy compared to those in the first and second tertiles. Women in the highest tertile of the ALP concentration distribution presented a lower rate of change in SBP and DBP during pregnancy (interaction term with gestational age βSBP = −0.004; 95% CI: −0.007 to −0.001; P = 0.02; βDBP = −0.003; 95% CI: −0.006 to −0.001; P = 0.01). Higher UA concentrations were associated with higher SBP levels only in overweight/obese women (β = 3.878; 95% CI: 0.687–7.068), whereas higher CRP concentrations (≥2.6 mg/L) were associated with higher DBP in under/normal weight women (β =2.252; 95% CI: 0.267–4.236).ALP, ALT, and Cr concentrations were positively associated with BP levels, whereas ALP was associated with a lower rate of change in BP. The associations of UA and CRP with BP differ according to the early-pregnancy BMI.

A cross-sectional analysis of the relationship between uric acid and coronary atherosclerosis in patients with suspected coronary artery disease in China.

BackgroundAlthough many studies have examined the relationship between uric acid (UA) and coronary artery disease (CAD), whether UA is an independent risk factor contributing to progression of CAD is still controversial. Whether UA plays a different role in different sexes is also unclear.MethodsA total of 1116 individuals with suspected CAD were stratified into four groups according to their serum UA quartiles in total (men and women combined), in men, and in women. The association of UA with coronary atherosclerosis was assessed by univariable and multivariable logistic regression.ResultsIn total and in women, the prevalence of any plaques and significant/severe stenosis was significantly increased with an increase in quartiles of UA (all P < 0.05). The proportion of triple-vessel disease and left main artery lesion was highest in the fourth quartile (both p < 0.05). Increasing quartiles of UA were significantly associated with a coronary artery calcium score (CACS) >10 (all P < 0.01). As UA levels increased in women, the incidence of double-vessel lesions (p = 0.017) and the proportion of mixed plaques (p = 0.022) were significantly increased. The proportion of a CACS of 0 in total, in men and women was highest in the first quartile (all P < 0.01). UA was the strongest predictor of significant stenosis, multivessel disease, and mixed plaques in women (all p < 0.05). UA was the only risk factor for mixed plaques in total (P = 0.046).ConclusionThe level of UA was significantly associated with coronary atherosclerosis in women, but not men.

Does uric acid qualify as an independent risk factor for cardiovascular mortality?

UA (uric acid) is the final product of purine metabolism in humans and is implicated in many disease conditions. Sustained hyperuricaemia has putative adverse roles in cardiovascular diseases. Despite strong evidence emerging from large epidemiological studies supporting the hypothesis that UA independently influences cardiovascular disease outcomes and mortality, a causal role is yet to be established. Serum UA is also considered as a useful biomarker for mortality in high-risk patients with acute coronary syndromes, heart failure and hypertension and in patients with Type 2 diabetes mellitus. Post-hoc analyses of clinical trial data suggest beneficial effects of reducing serum UA. However, these findings are inconclusive and are only hypothesis-generating. In the present issue of Clinical Science, Ndrepepa and co-workers have investigated the prognostic role of UA in high-risk Type 2 diabetic patients with established coronary artery disease in predicting 1-year survival and cardiovascular mortality. These results support the independent role of serum UA in predicting survival in Type 2 diabetic patients. However, long-term follow-up studies are required with serial UA measurement to establish the time-dependent association of UA with mortality outcomes.

A analysis on association of serum uric acid levels with ischemic stroke

Objective To investigate the relation between serum uric acid ( UA ) levels and ischaemic stroke.Methods 78 patients with ischaemic stroke were assigned to the study group and 80 healthy people were enrolled as control.Serum UA levels were compared between the two group.The association of UA with disease serverity and prognosis in patients was analyzed.Results UA levels were significantly higher in the study group than in the control group ( [375.93 ± 42.67]mol/L vs.[260.43 ±24.78]mol/L,P＜ 0.01 ).Serum UA levels increased gradually in all the patients with slight,moderate,or severe ischemic stroke ( P＜ 0.05 for all comparisons ).The number of the patients who were not cured or were dead was greater in the patients with an elevated UA level than in those with a normal UA level( P＜ 0.05 ).Conclusions Serum uric acid level was closely associated with the disease severity and prognosis in patients with ischemic stroke. Key words: Ischemic stroke; Uric acid

A prospective study of uric acid by glucose tolerance status and survival: the Rancho Bernardo Study

Abstract. Kramer CK, von Mühlen D, Jassal SK, Barrett‐Connor E (University of California, La Jolla, CA; and Hospital de Clinicas de Porto Alegre, RS, Brazil). A prospective study of uric acid by glucose tolerance status and survival: the Rancho Bernardo Study. J Intern Med 2010.Objectives. Little is known about uric acid (UA) levels and mortality in the context of glycaemia. We examined whether serum UA levels predict all‐cause and cardiovascular disease (CVD) mortality differentially in older adults by glucose tolerance status.Design and methods. Between 1984 and 1987, 2342 community‐dwelling men and women had an oral glucose tolerance test, UA measurement, and assessment of traditional CVD risk factors. We defined glucose tolerance status as normoglycaemia (NG), pre‐diabetes (pre‐DM), and type 2 diabetes mellitus (T2DM). Ninety per cent were followed for vital status up to 23 years. Death certificates were coded using the Ninth International Classification of Diseases.Results. Baseline age was 69.5 years; 44.4% were men. At baseline 939 had NG, 957 pre‐DM, and 446 T2DM. The mean UA by glucose tolerance status was 327.1, 362.8, and 374.7 μmol L−1. During follow‐up, there were 1318 deaths 46.8% attributed to CVD. In Cox‐regression analysis, each 119 μmol L−1 (2 mg dL−1) increment in UA levels predicted an increased hazard ratio (HR) for all‐cause deaths independent of age, smoking, body mass index, alcohol, physical activity, diuretic use and estimated glomerular filtration rate in all groups (NG: HR 1.25 95% CI 1.06–1.47, P =0.005; pre‐DM: HR 1.20 95% CI 1.06–1.37, P = 0.04; T2DM: HR 1.20 95% CI 1.01–1.47, P = 0.04). After adjusting for CVD risk factors, the UA association with CVD mortality was significant only in the pre‐DM and T2DM groups.Conclusion. All‐cause mortality was independently associated with UA in all groups, but UA predicted CVD mortality only in those with abnormal glucose tolerance.

A prospective study of uric acid by glucose tolerance status and survival: the Rancho Bernardo Study

Little is known about uric acid (UA) levels and mortality in the context of glycaemia. We examined whether serum UA levels predict all-cause and cardiovascular disease (CVD) mortality differentially in older adults by glucose tolerance status. Between 1984 and 1987, 2342 community-dwelling men and women had an oral glucose tolerance test, UA measurement, and assessment of traditional CVD risk factors. We defined glucose tolerance status as normoglycaemia (NG), pre-diabetes (pre-DM), and type 2 diabetes mellitus (T2DM). Ninety per cent were followed for vital status up to 23 years. Death certificates were coded using the Ninth International Classification of Diseases. Baseline age was 69.5 years; 44.4% were men. At baseline 939 had NG, 957 pre-DM, and 446 T2DM. The mean UA by glucose tolerance status was 327.1, 362.8, and 374.7 micromol L(-1). During follow-up, there were 1318 deaths 46.8% attributed to CVD. In Cox-regression analysis, each 119 micromol L(-1) (2 mg dL(-1)) increment in UA levels predicted an increased hazard ratio (HR) for all-cause deaths independent of age, smoking, body mass index, alcohol, physical activity, diuretic use and estimated glomerular filtration rate in all groups (NG: HR 1.25 95% CI 1.06-1.47, P =0.005; pre-DM: HR 1.20 95% CI 1.06-1.37, P = 0.04; T2DM: HR 1.20 95% CI 1.01-1.47, P = 0.04). After adjusting for CVD risk factors, the UA association with CVD mortality was significant only in the pre-DM and T2DM groups. All-cause mortality was independently associated with UA in all groups, but UA predicted CVD mortality only in those with abnormal glucose tolerance.