Association Of Serum Uric Acid Levels Research Articles

Effect of high sensitivity C-reactive protein on uric acid-related cardiometabolic risk in patients with coronary artery disease—a large multicenter prospective study

Although serum uric acid (SUA) is a risk factor for cardiometabolic outcome, but it remains unclear which patients with coronary artery disease (CAD) benefit the most from SUA lowering therapy (ULT). The association of SUA level, systemic inflammation and cardiometabolic risk is still unclear. The current study is aimed to examine whether SUA-associated cardiometabolic risk is modulated by systemic inflammation in CAD patients. A total of 16,598 CAD patients with baseline high-sensitivity C-Reactive Protein (hsCRP) and SUA available were included. Baseline and follow-up data were collected. The primary endpoint was major adverse cardiovascular and cerebrovascular events (MACCE), including death, myocardial infarction and stroke. In patients with hsCRP ≥ 2 mg/L, increasing quintiles of SUA were significantly associated with increased rates of 2-year MACCE (adjusted p < 0.001 for trend, p = 0.037 for interaction). Each unit increase in SUA levels was associated with a 11.3% increased risk of MACCE (adjusted p < 0.001, p = 0.002 for interaction). However, in patients with hsCRP < 2 mg/L, increasing quintiles of SUA were not associated with increased MACCE (adjusted p = 0.120). Elevated SUA levels are related to MACCE when hsCRP levels are 2 mg/L or more but not less than 2 mg/L. This finding suggests a potential benefit of combined ULT and anti-inflammation therapy in patients with hyperuricemia and greater systemic inflammation.

Association of uric acid with length of stay and mortality in pediatric hospitalized population

PurposeElevated uric acid (UA) levels have been associated with acute and chronic diseases, which could affect the prognosis of pediatric hospitalized patients. However, the association of UA levels with length of hospital stay (LOS) and mortality in hospitalized children and adolescents remains unknown. Therefore, the aim of this study was to evaluate the association of serum UA levels with in-hospital mortality and prolonged LOS in hospitalized children and adolescents. MethodsA retrospective cohort study was conducted, involving 128 patients under 18 years of age, admitted to a tertiary-care hospital between January 2014 and December 2018. UA levels were assessed with an average of 3 days before the in-hospital outcome (discharge or death). Logistic regression was used to determine the association of UA with prolonged LOS (defined as over 30 days of hospitalization), while Cox regression multivariate analysis was employed to assess UA as a predictor of in-hospital mortality. ResultsUA levels showed an inverse association with prolonged LOS. Specifically, for every 1 mg/dL increase in UA level, the odds of experiencing prolonged LOS decreased by 31% (OR=0.69; 95% CI: 0.50 – 0.95). Additionally, individuals with elevated UA levels had lower odds of prolonged LOS (OR = 0.23; 95% CI: 0.08 - 0.66). However, UA levels were not associated with in-hospital mortality (HR = 1.63; 95% CI: 0.94 – 2.82). ConclusionSerum UA is inversely associated with LOS among children and adolescents, but no association was observed with in-hospital mortality.

Serum Uric Acid Associates with Systemic Complement C3 Activation in Severe ANCA-Associated Renal Vasculitides.

Involvement of the complement system is key to the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated renal vasculitis, but immunometabolic implications, especially on serum uric acid (UA) levels, still need to be elucidated. A total of 34 patients with biopsy-proven ANCA-associated renal vasculitis between 2015 and 2020 were retrospectively enrolled. Serum UA levels were correlated with clinical and histopathological characteristics, separated for critically ill (CI, n = 19), myeloperoxidase (MPO)-ANCA (n = 21) and proteinase 3 (PR3)-ANCA (n = 13) subgroups. We here identified inverse correlations of serum UA levels and complement C3 levels in the total cohort (p = 0.005) and the CI subgroup (p < 0.001). Intrarenal complement C4d deposition in venules correlated with serum UA levels in the total cohort (p = 0.007) and in the CI subgroup (p = 0.016). Significant associations of serum UA levels and tubulitis in areas of scarred cortex (t-IFTA) were identified in the total cohort (p = 0.008), and both subgroups of CI (p = 0.034) and MPO-ANCA (p = 0.029). In PR3-ANCA, interstitial fibrosis (ci) was observed as the strongest association with serum UA levels (p = 0.022). Our observations broaden our current understanding of contributory metabolic factors that influence the initial disease course in ANCA-associated renal vasculitis.

Prevalence and association of hyperuricemia with liver function in Saudi Arabia: a large cross-sectional study.

Hyperuricemia is linked to an increased risk of various chronic diseases, but data on the prevalence and association of hyperuricemia with liver function in Saudi Arabia are scarce. Evaluate the prevalence, association, and risk measures of hyperuricemia and liver function in the Saudi population. Retrospective, cross-sectional analysis. Database on large portion of Saudi population. Laboratory data, age, and gender of the studied subjects were collected from Al Borg Diagnostics. Subjects were stratified, based on their uric acid (UA) levels, into three groups: hypouricemic, normouricemic, and hyperuricemic. The association of UA with liver enzymes was examined in all three groups. Association of serum UA levels with alanine transaminase (ALT), aspartate transferase (AST), alkaline phosphatase (ALP), and total bilirubin (TB). 13 314 subjects. Our study showed that the prevalence of hyperuricemia in the Saudi population is 17.3% (20.3% in males and 15.1% in females). We also found a positive correlation between ALT, AST, and TB with UA levels. The risk of being hyperuricemic was significantly increased in individuals with elevated ALT, AST, and TB. Individuals with elevated ALT, AST, and total TB had a higher chance of having hyperuricemia than those with normal activity. Notably, ALT, AST, and TB had good discriminating capacity for hyperuricemia. Hyperuricemia is highly prevalent in the Saudi population and is associated with compromised liver function. However, further studies are needed to elucidate the mechanisms underlying these findings in large prospective cohort studies in different populations. Lack of data on other potential confounding variables.

Association of serum uric acid levels with bone mineral density and the presence of osteoporosis in Chinese patients with Parkinson's disease: a cross-sectional study.

As the population ages, the incidence of osteoporosis among patients suffering from Parkinson's disease (PD) will surge continually, and the ensuing disability from falls is becoming a serious social burden. Due to its antioxidant properties, much literature has indicated the possible ability of serum uric acid (UA) to prevent ageing-related diseases caused by oxidative stress, including osteoporosis and PD. Therefore, this study was for exploring the connection of serum UA levels with bone mineral density (BMD) and the osteoporosis presence in Chinese PD patients. A cross-sectional design was used to statistically analyze 42 clinical parameters obtained from 135 patients with PD treated in Wuhan Tongji Hospital during 2020-2022. Multiple stepwise linear regression and multiple logistic regression analyses were constructed for identifying the association of serum UA levels with BMD as well as osteoporosis in PD patients, respectively. With receiver operative characteristic (ROC) curves, the optimal cutoff value was acquired for serum UA in the diagnosis of osteoporosis. According to the regression analysis adjusted for confounders, serum UA levels in PD patients had positive correlation with BMD at each site and negative correlation with the presence of osteoporosis (P < 0.05 for all). ROC curves determined that the optimal cutoff value for UA to perform well in diagnosing osteoporosis in PD patients was 284.27μmol/L (P < 0.001). Relatively higher serum UA levels in the physiological range can work as a biomarker of higher BMD, and were strongly linked to lower prevalence of osteoporosis in Chinese PD patients.

Gender Difference in Serum Levels of Uric Acid in Patients with Acute Myocardial Infarction

Introduction: Serum uric acid (SUA) level has been shown to be increased in patients with cardiovascular disease. This increase is generally higher in women than men. However, there is conflicting evidence based on different population. This study was aimed to explore and assed gender-based differences in the level of SUA in an Iranian subjects with acute myocardial infarction (AMI). We also investigated the relationship between SUA and clinical characteristics including, BMI, Killip class, hypertension and diabetes. Method: A total of 78 AMI patients, aged 20-90 years, comprised of 39 men and 39 women were enrolled in this cross sectional study. Venous blood samples were drawn from each of the participants after a nocturnal fasting on days 1, 3 and 4. Anthropometric indices, fasting plasma glucose, lipid profile and uric acid level as well as the ejection fraction (EF) were measured using standard protocols. Results: The mean SUA level in women was significantly higher than that in male on days 1,3,4 (P=0.001, 0.002, 0.03 respectively). A strong association was found between SUA on day 3 and hypertension, even after adjustment for BMI (OR=2.29, 95% CI, 1.21-4.3). There was also a significant correlation between SUA and age in women (p=0.03). However, such relationship was no found for diabetes. Conclusion: An increased level of SUA was observed in women. This increment was also associated with hypertension and age in women. Our results suggest a gender differences in the association of SUA level with AMI related adverse events.

Association between Serum Uric Acid Levels and Primary Open-angle Glaucoma: A Cross-sectional Study

Introduction: There is an intricate association between serum Uric Acid (UA) levels and Primary Open Angle Glaucoma (POAG). UA levels in the blood are known to be a good indicator of antioxidant function, and a decrease in UA plays a key role in the pathogenesis of POAG. However, the association of serum UA and Uric Acid Creatinine Ratio (UACR) in POAG cases in the Indian population remains unexplored. Aim: To investigate the association of serum UA levels and serum UACR with POAG. Materials and Methods: This cross-sectional study was conducted among patients who attended the Outpatient Department (OPD) of Opthalmology at Maharajah’s Institute of Medical Sciences, Vizianagaram, Andhra Pradesh, India. The duration of the study was one year and six months, from January 15, 2021 to July 15, 2022. The study included 200 recently diagnosed patients with POAG, who were divided into three groups based on Intraocular Pressure (IOP): Group 1 (mild) with an IOP of 21-30 mmHg, group 2 (moderate) with an IOP of 31-50 mmHg, and group 3 (severe) with an IOP greater than 51 mmHg. Age and gender-matched 199 healthy subjects were included as the control group. Blood samples were collected from the study subjects after obtaining informed consent and were tested for serum UA (using the modified Trinder method) and serum creatinine (using Jaffe’s method) in a semiautomatic analyser (Erba chem 7). The data were analysed using Statistical Package for Social Sciences (SPSS) version 21.0 software and MS Excel 2007. Results: The mean age of the study participants of all three groups was found to be 51.19±5.06 years with 46.7% male and 53.3% female subjects. The serum UA levels were 5.55±0.74 mg/dL in the mild POAG group, 4.1±0.5 mg/dL in the moderate POAG group, and 2.67±0.6 mg/dL in the severe POAG group (p-value &lt;0.001). The present study also found that among the three study groups of POAG, UA levels were the lowest in the severe POAG group, followed by the moderate POAG group, and then the mild POAG group. This pattern was observed in both the males and females population. Conclusion: The present study found that serum UA levels were decreased in POAG patients compared to the normal healthy control group. Furthermore, the study revealed a significant negative association between serum UA levels and serum UACR levels with the severity of POAG.

Detailed association between serum uric acid levels and the incidence of chronic kidney disease stratified by sex in middle-aged adults

Background and aimsChronic kidney disease (CKD) is a global health burden. Previous studies have shown a J- or U-shaped association between serum uric acid (SUA) and cardiovascular mortality. We assessed the risk of CKD incidence in a refined SUA category in middle-aged adults stratified by sex. MethodsWe analyzed data from 138,511 participants <65 years old (29.6% women; mean age 44.1 years) without CKD at baseline acquired from the JMDC database. The Cox model was used to assess the adjusted hazard ratio (HR). ResultsDuring the mean follow-up period of 4.68 years, 12,589 participants developed CKD. The fully adjusted HRs (95% confidence interval [CI], p-value) for CKD incidence in men with SUA <4.0, 10.0–10.9 and ≥ 11.0 mg/dL compared to men with SUA 4.0–4.9 mg/dL were 1.13 (1.01–1.26, p = 0.030), 1.98 (1.32–2.97, p = 0.0010), and 3.74 (1.68–8.35, p = 0.0013), respectively. The fully adjusted HRs for CKD incidence in women with SUA <4.0, 8.0–8.9, and ≥9.0 mg/dL compared to women with SUA 4.0–4.9 mg/dL were 1.08 (1.01–1.16, p = 0.032), 2.39 (1.07–5.35, p = 0.034), and 3.20 (0.80–12.8, p = 0.10), respectively. ConclusionsBoth high and low SUA levels were identified as risk factors for CKD incidence in middle-aged men and women. The association of SUA levels with the increase in the risk of CKD incidence differed by sex, and the range of SUA levels associated with an increase in the risk of CKD incidence varied by sex.

Pre-Conditioning Serum Uric Acid as a Risk Factor for Sinusoidal Obstruction Syndrome of the Liver in Children Undergoing Hematopoietic Stem Cell Transplantation

Objective:Uric acid (UA), a known danger signal released from injured cells, is a valuable sign of inflammation. We aimed to evaluate the association of serum UA levels before the start of conditioning regimens with the risk of hepatic sinusoidal obstruction syndrome (SOS) development after hematopoietic stem cell transplantation (HSCT).Materials and Methods:Two hundred and twenty-two children who underwent allogeneic HSCT at the Pediatric BMT Unit of Hacettepe University between 2000 and 2014 were included in this retrospective study. Serum UA levels were measured before conditioning as an indicator of the pre-transplant inflammatory status of the patients. Patients with and without a diagnosis of SOS were compared regarding primary diagnosis, previously described risk factors for SOS, and pre-conditioning serum UA.Results:SOS was diagnosed in 42 patients who had higher pre-conditioning serum UA levels compared to those who did not. Pre-transplant serum creatinine, gamma-glutamyl transferase, bilirubin, ferritin, and C-reactive protein levels did not differ significantly among patients with and without SOS; however, serum albumin was lower in the patients who developed SOS. Receiver operating characteristic analysis revealed that a pre-conditioning UA level higher than 3.32 mg/dL was predictive of SOS. When applied to a multivariate model, only pre-conditioning UA and albumin levels remained significant risk factors for SOS (UA: odds ratio [OR], 2.54; 95% confidence interval [CI], 1.26-5.12, p=0.009; albumin: OR, 0.45, 95% CI, 0.22-0.95, p=0.037).Conclusion:Our results suggest that pre-conditioning serum UA is an independent risk factor for SOS, and it might be used as an early predictor of hepatic SOS together with previously described clinical and laboratory parameters.

Tea consumption and serum uric acid levels among older adults in three large-scale population-based studies in China

Background and aimsThe association between serum uric acid (SUA) and tea consumption has been studied in previous work, and there were arguments among various population group employed as well as different statistical approaches. The aim of this work is to investigate the tea effect on SUA levels among older adults by comparing three large-scale populations with both cross-sectional and longitudinal analyses.MethodWe examined the relationship between intake and SUA levels among older adults using linear regression. All the studies include the parameters SUA levels, tea intake, age, sex, education level, smoking status, alcohol drinking status, body mass index (BMI), and health history (diabetes, hypertension, and fasting plasma glucose). The cross-sectional analyses were conducted with 4579 older adults in the Weitang Geriatric Diseases Study (WGDS, ≥60 years), 2440 in the China Health and Nutrition Survey (CHNS, ≥60 years) and 1236 in the Chinese Longitudinal Healthy Longevity Survey (CLHLS, ≥62 years); and the longitudinal analyses were performed with 3870 (84.5%) in the WGDS and 420 (34.0%) in the CLHLS. Multivariable linear regression analyses were performed in both cross-sectional and longitudinal studies.ResultsCross-sectional studies showed that tea consumers tended to have higher SUA levels than non-tea consumers in all the three datasets (P < 0.05). However, longitudinal associations of SUA levels with tea consumption had no statistical significance (P>0.05). The results of sex-stratified analyses were consistent with those of the whole datasets.ConclusionsThis work implied that any possible association between tea consumption and SUA levels could be very weak.

A cross-sectional study on the association of serum uric acid levels with depressive and anxiety symptoms in people with epilepsy

BackgroundHigh serum uric acid (SUA) levels may provide protection against depression and anxiety through its defensive role in oxidative damage. The aim of this study was to test the hypothesis of the independent associations of lower SUA levels with depressive and anxiety symptoms among patients with epilepsy (PWE).MethodsA cross-sectional study was performed among 320 PWE aged ≥18 years old in Northeast China. The Neurological Disorders Depression Inventory for Epilepsy (NDDI-E; Chinese version) and the Generalized Anxiety Disorder-7 scale (GAD-7; Chinese version) were used as screening tools for depressive and anxiety symptoms for PWE. Serum uric acid levels were measured. The associations of SUA levels with depressive and anxiety symptoms were assessed by using binary logistic regression models, with adjustment for the related risk factors (P< 0.05).ResultsLower SUA tertiles were significantly associated with higher C-NDDI-E and GAD-7 scores compared with the higher two tertiles (p=0.001, and p= 0.002). Patients with depressive symptoms exhibited significantly lower SUA levels compared to those without depressive symptoms (p< 0.001). SUA levels of patients with anxiety symptoms were significantly lower than those of patients without anxiety symptoms (p< 0.001). The first and second SUA tertiles were associated with depressive symptoms, with the third tertile group as the reference group, after adjusting for confounders (first tertile: OR = 4.694, 95% CI = 1.643~ 13.413, P = 0.004; second tertile: OR = 3.440, 95% CI = 1.278~9.256, P = 0.014). However, The first and second SUA tertiles were not associated with the risk of anxiety symptoms compared with the third tertile in the adjusted logistic regression model (First tertile: OR = 1.556, 95% CI = 0.699~3.464, P = 0.279; second tertile: OR = 1.265, 95% CI = 0.607~2.635, P = 0.530).ConclusionWe found that lower SUA levels were independently associated with depressive symptoms but not with anxiety symptoms among PWE. Further well-designed prospective cohort studies are required to determine the causality of the associations and to further clarify the mechanisms of SUA in depressive symptoms.

The role of serum uric acid in the prediction of graft‐versus‐host disease in allogeneic hematopoietic stem cell transplantation

BackgroundUric acid (UA) level is of the valuable signs of inflammation. However, the role of UA in the outcomes of hematopoietic stem cell transplantation (HSCT) such as GVHD and patients’ overall survival is still a matter of debate. In this study, we aimed to evaluate the relationship between UA levels and GVHD incidence and overall survival in allogeneic HSCT patients.MethodsA total of 201 patients who were admitted for allogeneic transplantation at Taleghani hospital, Tehran, Iran, were considered for retrospective analysis. Serum UA levels from 1 week before transplantation until 2 weeks after transplantation were used to determine thresholds and find out the association of serum UA levels with GVHD and overall survival.ResultsWe showed that the determined thresholds using receiver operating characteristic curves have poor predictive value for GVHD and overall survival. The patients with serum UA higher than 3.4 mg/dL had 37% lower odds of GVHD incidence and 35% lower hazard of death than patients with UA lower than 3.4 mg/dL.ConclusionOur results indicated that serum UA levels lower than 3.4 mg/dL could significantly increase the incidence of GVHD and hazard of death. The antioxidant functions of UA could explain the lower incidence of GVHD in hyperuricemic patients. However, the inconsistencies of the previous studies require further investigation to elucidate the role of UA in the prediction of GVHD.

The association of serum uric acid level with dialysis adequacy and nutritional status in maintenance hemodialysis

Objective To investigate the association of serum uric acid(SUA) level with dialysis adequacy and nutritional status in maintenance hemodialysis(MHD). Methods From July 2016 to July 2018, a total of 100 MHD patients were recruited in our hospital. Patients were allocated into dialysis adequacy group and inadequate dialysis group according to the urea drop rate. Also, patients were divided into good nutrition group and malnutrition group depending on their serum albumin levels. Complete blood count, serum albumin, creatinine, urea nitrogen, SUA, calcium, phosphorus, C-reactive protein, β2 microglobulin and intact parathyroid were assayed. The association between SUA and clinical parameters were analyzed. Results Compared to inadequate dialysis patients, the SUA, creatinine, urea nitrogen, serum phosphorus and C-reactive proteinlevels were significantly lower in dialysis adequacy patients(P<0.05). Also, compared to malnutrition group, the SUA and serum albumin levels were significantly higher in good nutrition group(P<0.05). However, C-reactive protein levels were significantly lower in good nutrition group(P<0.05). Correlation studies revealed that SUA levels were positively correlated with creatinine(r=0.202, P<0.05), while negatively correlated with age(r=-0.303, P<0.01) and urea drop rate(r=-0.220, P<0.05). Conclusions SUA levels in MHD are closely correlated with nutritional status and dialysis adequacy. Higher SUA in MHD patients may suggest the relatively good nutritional status, but hyperuricemia may also associate with inadequate dialysis. Key words: Renal Dialysis; Uric Acid; Nutritional Status

Association of hyperuricemia and pulmonary hypertension: A systematic review and meta-analysis

Objectives: To investigate the association of hyperuricemia with pulmonary hypertension (PH) in term of subsequent development, severity, and prognosis of PH.Methods: The authors systematically reviewed articles from databases and conducted meta-analyses as follows: (1) association of serum uric acid (UA) levels with the presence of PH; (2) association between serum UA levels and subsequent development of PH, in terms of odds ratio of the development of PH; and (3) association of serum UA levels with severity and prognosis of PH, in terms of pulmonary arterial pressure and hazard ratio of death.Results: Twenty-six studies published between 1999 and 2017 were included. The level of serum UA was higher in subjects with PH than subjects without PH and this finding was observed regardless of status of diuretics use or renal function. The odds ratio of the development of PH was 2.32 (95% CI, 1.05–5.15) in subjects with hyperuricemia. Pulmonary arterial pressure among subjects with PH was also higher in subjects with hyperuricemia than subjects with normouricemia. There was a 19% increased hazard ratio of death (95% CI, 1.06–1.33) among patients with PH who had hyperuricemia.Conclusion: Hyperuricemia is associated with the subsequent development, worse severity and poor prognosis of PH.

Cardiovascular Autonomic Neuropathy and Uric Acid in Subjects with Type 1 Diabetes—Preventing Early Renal Loss (PERL) in Type 1 Diabetes Trial

Elevated serum uric acid (SUA), an established risk factor for diabetic nephropathy (DN) may also be a risk factor for cardiovascular autonomic neuropathy (CAN). We evaluated the cross-sectional association between CAN and SUA levels in subjects with type 1 diabetes (T1D), mild to moderate chronic kidney disease (CKD) and a SUA ≥4.5 mg/dl enrolled in the ongoing PERL trial that is evaluating the effect of SUA lowering by allopurinol on kidney function decline, specifically iohexol plasma disappearance glomerular filtration rate (iGFR). Also measured are estimated GFR (eGFR) and albumin excretion rates (AER). Measures of baseline CAN included resting heart rate, standard deviation of normal RR interval (SDNN), and QTi (Bazzett formula) derived from resting ECG recordings (RR interval extracted from digital ECG images by ECGSCAN software). Four hundred ninety seven PERL participants had valid baseline CAN and renal function data (age 51 ± 11 years, 68% male, T1D duration 35 ± 12 years, HbA1c 8±1%). Subjects in the highest tertile of serum UA levels had worse measures of renal function (iGFR 60 ± 16 vs. 74 ± 60 ml/min/1.73 m2, eGFR 65.7 ± 18.1 vs. 82.7 ± 17.2 ml/min/1.73 m2, AER 370 ± 783 vs. 1181 ± 475 mcg/mg creatinine) compared to those in the lowest tertile. SDNN correlated negatively with SUA levels (r = -0.11, P = 0.0093). In a multiple linear regression model, lower SDNN was associated with higher SUA levels independent of age, gender, BMI, blood pressure, and HbA1c (β = -0.061, SE= 0.021, P = 0.0049), but this association was no longer significant when adjusted for iGFR (β = -0.0184, SE= 0.024, P = 0.46). In summary, elevated SUA was significantly associated with CAN in subjects with T1D independent of some traditional cardiovascular risk factors. This relationship operated, at least in part, through the inverse association of SUA levels with renal function. Disclosure M. Jaiswal: None. A. Doria: Research Support; Self; Sanofi-Aventis. M. Mauer: None. R. Pop-Busui: Research Support; Self; AstraZeneca.

Sex-specific association between serum uric acid and self-reported snoring in rural China: a cross-sectional study.

Until now, information has been rare on the association of serum uric acid (SUA) with self-reported snoring. Therefore, the purpose of this study was to explore the sex-specific relationship between SUA and self-reported snoring in a general Chinese population. A large cross-sectional study of 10,912 participants aged ≥35years old were recruited from rural areas of Liaoning Province in China during 2012 to 2013. SUA were divided into quartiles separated for males and females. Anthropometric measurements and blood biochemical indexes were examined according to standard protocols. Sleep duration and self-reported snoring status were investigated by trained personnel using a structured questionnaire. The prevalence of self-reported snoring was 37.9% (n=2197) among females and 47.4% (n=2420) among males, respectively. The proportion of self-reported snoring presented a significant linear increase across the quartile of SUA level in both sexes. In multivariate logistic regression analysis adjusted for possible confounders, the odds ratio (OR) for SUA with regard to self-reported snoring was significantly higher in females. The OR of self-reported snoring associated with per 1 SD increase in SUA was 1.208 (95%CI 1.118-1.305, P<0.001). The highest quartile of SUA (>293μmol/L) conferred an independently increased risk for self-reported snoring with OR of 1.643 (95%CI 1.384-1.950, p<0.001) compared to the lowest quartile of SUA (<209μmol/L). However, there were no significant relationships between SUA and self-reported snoring among males in all the models. Our study showed that in rural China, SUA was positively correlated with an increased risk for self-reported snoring in females but not in males. The strong association of SUA levels with self-reported snoring in females emphasizes the necessity of stratifying the sex in investigations of self-reported snoring and encourages exploration of SUA as an effective clinical tool of self-reported snoring risk.

Higher serum uric acid is associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in healthy postmenopausal women

Higher serum uric acid (UA) was associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in postmenopausal women. Furthermore, UA suppressed osteoclastogenesis and decreased production of reactive oxygen species in osteoclast precursors, indicating UA may have beneficial effects on bone metabolism as an antioxidant. UA is known to play a physiological role as an antioxidant, and oxidative stress has detrimental effects on bone metabolism. In the present study, we investigated the association of serum UA level with the osteoporosis-related phenotypes and its direct effect on bone-resorbing osteoclasts using in vitro systems. This is a large cross-sectional study, including 7,502 healthy postmenopausal women. Bone mineral density (BMD) and serum UA concentrations were obtained from all subjects. Data on bone turnover markers and lateral thoracolumbar radiographs were available for 1,023 and 6,918 subjects, respectively. An in vitro study investigated osteoclastogenesis and reactive oxygen species (ROS) levels according to UA treatment. After adjusting for multiple confounders, serum UA levels were positively associated with BMD at all sites (all p < 0.001). Compared with the participants in the highest UA quartile, the odds for osteoporosis were 40% higher in those in the lowest quartile. The serum UA levels were inversely related to both serum C-terminal telopeptide of type I collagen and osteocalcin levels (p < 0.001 and p = 0.004, respectively). Consistently, subjects with vertebral fracture had lower serum UA levels, compared with those without it (p = 0.009). An in vitro study showed that UA decreased osteoclastogenesis in a dose-dependent manner and reduced the production of ROS in osteoclast precursors. These results provide epidemiological and experimental evidence that serum UA may have a beneficial effect on bone metabolism as an antioxidant in postmenopausal women.

Renal function‐dependent association of serum uric acid with metabolic syndrome and hepatic fat content in a middle‐aged and elderly Chinese population

The effect of uric acid (UA) on the pathogenesis of metabolic disorders is highly dependent on its physicochemical properties, and hyperuricaemia associated with different conditions may have different clinical meanings. The aim of the present study was to investigate the association of serum UA levels with metabolic syndrome and non-alcoholic fatty liver disease (NAFLD) in a middle-aged and elderly population with normal and impaired renal function. The cross-sectional study was performed on 1141 participants (426 men, 715 women; mean age 62years) enrolled from the Shanghai Changfeng community. Each participant underwent a standard interview, with anthropometric and laboratory measurements. Hepatic fat content (HFC) was determined by a newly established quantitative ultrasound method. Univariate correlation analysis showed that serum UA was associated with all components of metabolic syndrome and HFC (r=0.193, P<0.001), especially in participants with a normal estimated glomerular filtration rate (eGFR; r=0.255, P<0.001). Logistic regression analysis demonstrated an independent association of serum UA with metabolic syndrome and NAFLD in participants with normal renal function, but not in those with eGFR <90mL/min per 1.73m(2) . Furthermore, multivariate linear analysis showed that UA levels were independently associated with HFC (P=0.003), but only in participants with normal eGFR. Elevated serum UA is independently associated with metabolic syndrome and NAFLD in patients with normal renal excretory function. However, in those with renal insufficiency, hyperuricaemia has no association with metabolic disorders.

An association between uric acid levels and renal arteriolopathy in chronic kidney disease: a biopsy-based study

Uric acid (UA) can induce renal arteriolopathy in animal models. Whether there is an association between UA and renal arteriolopathy in patients with chronic kidney disease (CKD) is unknown. Here, we examined the cross-sectional association of serum UA levels with renal arteriolar hyalinosis and wall thickening. Arteriolar parameters were assessed by semiquantitative grading (max: grade 3) of arterioles in 167 patients with CKD (mean age, 42.4 years; 86 men and 81 women) who underwent renal biopsy. The mean serum UA level was 6.4 mg dl(-1). We observed hyalinosis in 94 patients (56%) and wall thickening in 119 patients (71%). As the UA level tertile increased, the proportion of higher-grade (grade 2 and 3) hyalinosis and wall thickening increased (hyalinosis, P<0.0001 and wall thickening, P=0.0002, for trend). Multiple logistic analysis adjusted for age ≥40 years, sex, hypertension status, diabetes mellitus status and estimated glomerular filtration rate <60 ml min(-1) per 1.73 m(2) showed that hyperuricemia (UA ≥7 mg dl(-1)) was significantly associated with a higher risk of hyalinosis (adjusted odds ratio: 3.13; 95% confidence interval: 1.23-7.94; P=0.02) and higher-grade (equal to or higher than the mean value) wall thickening (adjusted odds ratio: 2.66; 95% confidence interval: 1.11-6.38; P=0.03). Hence, these results suggest that hyperuricemia may be related to renal arteriolar damage in patients with CKD.

Serum Uric Acid Levels Are Associated with Polymorphism in the SAA1 Gene in Chinese Subjects

ObjectiveSerum uric acid (SUA) is a cardiovascular risk marker associated with inflammation. The serum amyloid A protein (SAA) is an inflammatory factor and is associated with cardiovascular disease (CVD). However, the relationship between genetic polymorphisms of SAA and SUA levels has not been studied. The objective of this study was to investigate the association between SUA levels and SAA genetic polymorphisms.MethodsAll participants were selected from subjects participating in the Cardiovascular Risk Survey (CRS) study. The single nucleotide polymorphism (SNP) rs12218 of the SAA1 gene was genotyped by using the polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method. The association of SUA levels with genotypes was assessed by using the general liner mode.ResultsThe SNP rs12218 was associated with SUA levels by analyses of a dominate model (P = 0.002) and additive model (P = 0.005), and the difference remained significant after adjustment of sex, age, obesity, ethnicity, HDL-C, alcohol intake, smoking, and creatinine (P = 0.006 and P = 0.023, respectively). The TT genotype was associated with an increased SUA concentration of 39.34 mmol/L (95% confidence interval [CI], 3.61–75.06, P = 0.031) compared with the CC genotype, and the TT genotype was associated with an increased SUA concentration of 2.48 mmol/L (95% CI, 6.86–38.10; P = 0.005) compared with the CT genotype.ConclusionsThe rs12218 SNP in the SAA1 gene was associated with SUA levels in Chinese subjects, indicating that carriers of the T allele of rs12218 have a high risk of hyperuricemia.