Serum uric acid to creatinine ratio and metabolic syndrome in postmenopausal Chinese women

Association between the serum uric acid/serum creatinine ratio and cognitive function in older adults: NHANES in the United States

Cognitive impairment can potentially become a significant health concern in older adults. However, early effective diagnostic methods are still lacking. Therefore, we utilized the NHANES database in the US to investigate the relationship between serum uric acid to serum creatinine (SUA/SCR) ratio and cognitive impairment. In our study, a total of 3874 participants were included (2001-2002, 2011-2014). Weighted t tests or chi-square tests were utilized to analyze the basic characteristics of the population. Weighted logistic regression analysis, smooth-fit curves, threshold effects, and subgroup analysis were conducted to investigate the correlation between the SUA/SCR and cognitive impairment. In this study, the SUA/SCR was significantly lower in individuals with cognitive impairment. The logistic regression model, after adjusting for all covariates, revealed that the Q2-Q4 were 0.65 (95% CI 0.49, 0.86), 0.60 (95% CI 0.40, 0.90), 0.55 (95% CI 0.39, 0.77) respectively. This indicates that participants in the Q4 had a 45% reduced risk of cognitive impairment. Smooth-fit curves and threshold effect analysis revealed a nonlinear relationship between SUA/SCR and cognitive impairment, with a turning point at 4.13. Subgroup analysis showed no statistically significant differences in the relationship between SUA/SCR and cognitive impairment among different subgroups (P > 0.05). Our findings indicate a negative correlation between the SUA/SCR and the risk of cognitive impairment in the population of adults aged 60 and above in the US. This suggests that the SUA/SCR holds promise as a potential indicator for cognitive impairment.

Does Serum Uric Acid to Creatinine Ratio Predict Mortality Risk in Patients With Heart Failure?

BACKGROUND

Previous studies have established a positive correlation between serum uric acid to creatinine (SUA/Cr) ratio and cardiovascular disease, but the relationship between SUA/Cr ratio and the prognosis of heart failure (HF) remains unknown. This study investigated the potential of SUA/Cr ratio as a prognostic predictor for patients with HF.

METHODS

This single-center prospective cohort study enrolled 2,122 patients with HF between March 2013 and June 2017. All patients were divided into 3 groups according to SUA/Cr ratio tertiles and were followed up with until December 31, 2022. The association between SUA/Cr ratio and the prognosis of HF was assessed using the Cox proportional hazards model.

RESULTS

The mean (SD) age and mean (SD) SUA/Cr ratio of the study cohort (66% male) were 59.3 (14.7) years and 4.71 (2.09), respectively. During a median follow-up period of 15 months (range, 11-26 months), 390 end-point events were observed. Prognosis analysis revealed that a high SUA/Cr ratio was associated with an increased mortality risk of HF (hazard ratio, 1.62 [95% CI, 1.26-2.09]; P < .001) compared with the SUA/Cr ratio in the lowest tertile. After adjusting for covariates, the hazard ratio for mortality risk of HF was 1.71 (95% CI, 1.23-2.37; P = .001). Subgroup analysis showed that mortality risk increased in direct proportion with the SUA/Cr ratio in female patients, patients with a history of hypertension and β-blocker use, and patients with UA levels below 428 μmol/L and creatinine levels less than 97 mg/dL. Stratification by age; by history of diabetes, hyperlipidemia, and smoking; and by level of fasting plasma glucose, however, had no obvious effect on the association between SUA/Cr ratio and HF prognosis. Patients with higher SUA/Cr ratios had reduced left ventricular ejection fraction and increased left ventricular end-diastolic diameter.

CONCLUSION

A high SUA/Cr ratio was an independent risk factor for the mortality risk of HF.

TG: A Mediator of the Relationship of Serum Uric Acid to Creatinine Ratio and Nonalcoholic Fatty Liver Disease in Non-Obese Patients with Type 2 Diabetes

Background

The study estimated the association between NAFLD and SUA/Cr in Chinese non-obese patients with type 2 diabetes mellitus (T2DM) and also investigated mediating effect of TG.

Methods

All patients were divided into NAFLD group (n = 420) and non-NAFLD group (n = 347). The differences of biochemical indicators between the two groups were compared. The link between SUA/Cr and other parameters was checked through Spearman correlation analysis. Differences in the incidence rate of NAFLD between SUA/Cr and TG 3 tertile subgroups were tested by chi-squared. To explore the independent influence of SUA/Cr and TG on NAFLD, logistic regression was performed. The predictive value of SUA/Cr and SUA/Cr combined with BMI for NAFLD was analyzed using ROC curves. In addition, to confirm whether TG has a mediating effect on the link of SUA/Cr and NAFLD, we conducted a mediating analysis.

Results

NAFLD group had higher SUA/Cr values than individuals without NAFLD (P < 0.01). SUA/Cr was linked with TC and TG (r = 0.081, 0.215 respectively). NAFLD prevalence increased progressively from quartile 1 to quartile 3 of SUA/Cr (44% vs 57% vs 62%). Prevalence of NAFLD increased from quartile 1 to quartile 3 of TG (35.8% vs 58.7% vs 69.9%). Analysis of the logistic regression revealed that SUA/Cr and TG were statistically linked with NAFLD. The ROC curve pointed out that the area under the curve (AUC), sensitivity and specificity of SUA/Cr were 0.59, 0.629 and 0.522, respectively. The AUC, sensitivity and specificity for SUA/Cr combined with BMI were 0.719, 0.644 and 0.677, separately. The mediation analysis showed a statistically direct effect of SUA/Cr on NAFLD (β=0.148, 95% CI: 0.0393, 0.2585). The function of SUA/Cr on NAFLD partially mediated by TG (β=0.1571, 95% CI: 0.0704, 0.2869).

Conclusion

SUA/Cr was significantly associated with NAFLD in non-obese T2DM patients, and TG partially mediated this association. SUA/Cr can be applied to predict for NAFLD.

The dynamic nexus: exploring the interplay of BMI before, during, and after pregnancy with Metabolic Syndrome (MetS) risk in Chinese lactating women

BACKGROUND AND AIM

The health implications of BMI and MetS in lactating women are significant. This study aims to investigate the relationship between risk of Mets in lactation and BMI in four stages: pre-pregnancy, prenatal period, 42 days postpartum, and current lactation.

METHODS AND RESULTS

A total of 1870 Lactating Women within 2 years after delivery were included from "China Child and Lactating Mother Nutrition Health Surveillance (2016-2017)". Logistic regression model and Restricted cubic spline (RCS) were used to estimate the relationship between BMI and risk of MetS. ROC analysis was used to determine the threshold for the risk of MetS. Chain mediating effect analysis was used to verify the mediating effect. BMI of MetS group in all stages were higher than non-MetS group (P < 0.0001). There were significant positive correlations between BMI in each stage and ORs of MetS during lactation (P < 0.05). The best cut-off values for BMI in the four stages were 23.47, 30.49, 26.04 and 25.47 kg/m2. The non-linear spline test at BMI in 42 days postpartum, current and MetS in lactation was statistically significant (P non-linear = 0.0223, 0.0003). The mediation effect of all chains have to work through lactation BMI. The total indirect effect accounted for 80.95% of the total effect.

CONCLUSIONS

The risk of MetS in lactating women is due to a high BMI base before pregnancy and postpartum. High BMI in all stages of pregnancy and postpartum were risk factors for MetS in lactation. BMI during lactation plays a key role in the risk of MetS.

The association between lipid profile, oxidized LDL and the components of metabolic syndrome with serum mineral status and kidney function in individuals with obesity

BACKGROUND

Metabolic syndrome (MetS) is presented with a cluster of cardio-metabolic risk factors with widespread prevalence. In the present case-control study, we aimed to examine the relationship between several minerals and renal function tests with the components of MetS in individuals with obesity.

METHODS

This study included 127 individuals with obesity of both gender with or without MetS as the case and control, respectively. MetS was characterized based on the Adult Treatment Panel III (ATP III) criteria. Anthropometric variables and blood pressure were recorded. Mineral status including serum magnesium, copper, calcium, phosphorous, and iron were measured using standard colorimetric methods. Also, the serum lipid levels, concentrations of oxidized low-density lipoprotein (Ox-LDL), and renal function tests, including total protein, albumin, urea, creatinine, and uric acid were evaluated using commercial enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

According to our results, individuals with obesity and MetS had higher levels of waist circumference (WC) and diastolic blood pressure (P < 0.05) compared to individuals with obesity and without MetS. Moreover, individuals with obesity and MetS had higher levels of serum total cholesterol (TC), triglyceride (TG), insulin, and iron (P < 0.05). In individuals with obesity and MetS, iron and albumin showed a positive relationship with LDL cholesterol and TG concentrations, respectively (P < 0.05 for all of them). Also, there was a positive association between serum magnesium and Ox- LDL in individuals with obesity with MetS. While, in individuals with obesity and without MetS, only a positive association between urea and uric acid with WC was observed (P < 0.05).

CONCLUSION

Our results suggest that disturbed serum lipids in obesity-metabolic syndrome is associated with homeostatic changes in the level of minerals or proteins that are involved in their metabolism. Although, further studies are needed to better explain and clarify the underlying mechanism of observed relationships.

Serum Uric Acid is a Better Indicator of Kidney Impairment Than Serum Uric Acid-to-Creatinine Ratio and Serum Uric Acid-to-High-Density Lipoprotein Ratio: A Cross-Sectional Study of Type 2 Diabetes Mellitus Patients

Background

Type 2 diabetes mellitus (T2DM) patients are likely to develop kidney disease. Early diagnosis, finding predictors and controlling risk factors are of great significance for T2DM patients. This study investigated the ability of uric acid (UA), the uric acid to creatinine (CR) ratio (UA/CR) and the uric acid to high-density lipoprotein cholesterol ratio (UHR) to assess the kidney function of T2DM patients and determined the relationship between the three indicators and the estimated glomerular filtration rate (eGFR).

Methods

A total of 1326 adult T2DM patients were enrolled in the current study. Patients were stratified into three groups according to their eGFRs. Spearman correlation was used to analyze the correlation between three indicators and the clinical variables. Logistic regression analysis was used to assess the association between the three indicators and diabetic kidney disease (DKD) and kidney impairment (eGFR <60 mL/min/1.73 m2). Receiver operating characteristic (ROC) analyses and the area under the ROC curve (AUC) were then used to assess the ability of UA, UA/CR, and UHR to discriminate kidney impairment in T2DM.

Results

UA and UHR demonstrated a positive association with DKD risk (P < 0.05). The odds ratios (ORs) were 1.005 (95% CI, 1.004-1.007) and 1.057 (95% CI, 1.039-1.076), respectively. UA/CR was negatively correlated with DKD risk (OR, 0.922 (95% CI, 0.876, 0.970), P < 0.05). Furthermore, UA and UHR demonstrated a strong positive association with kidney impairment risk, while UA/CR was negatively correlated with kidney impairment risk in T2DM patients (P < 0.05 for all) after adjusting for confounding factors. UA had the highest AUC (0.762) among the three indicators. UHR had a greater AUC (0.713) than UA/CR, which had an AUC value of 0.148 (p < 0.001).

Conclusion

UA is the best indicator of renal impairment (eGFR <60 mL/min/1.73 m2) among the three indicators, and UHR is a better indicator than UA/CR.

The Association of Serum Uric Acid Levels and Various Uric Acid-Related Ratios with Insulin Resistance and Obesity: A Preliminary Study in Adolescents

BACKGROUND

Studies have shown that serum uric acid levels and uric acid-related ratios, such as uric acid-to-albumin ratio (UAR), uric acid-to-creatinine ratio (UCR), uric acid-to-high-density lipoprotein cholesterol (HDL cholesterol) ratio (UHR), and uric acid-to-lymphocyte ratio (ULR), are associated with various diseases and their complications, and that these ratios can be used as biomarkers. In the current study, we aimed to investigate uric acid levels in obese adolescents and the relationship of uric acid-related ratios with insulin resistance and obesity for the first time in the literature.

METHODS

A total of 100 adolescents (60 obese and 40 healthy) aged 10-17 years were retrospectively included. Participants were assigned to two groups: the obese group and the healthy control group. Obesity was defined as a body mass index (BMI) >the 95th percentile for age and gender. Demographic and laboratory data (serum glucose, urea, creatinine, uric acid, albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), C-reactive protein (CRP), total cholesterol, triglyceride, HDL cholesterol, thyroid-stimulating hormone (TSH), free T4 (fT4), insulin levels, and complete blood count) were obtained from the laboratory information management system. A homeostatic model of assessment for insulin resistance (HOMA-IR), low-density lipoprotein cholesterol (LDL cholesterol), and uric acid-related ratios were calculated.

RESULTS

Uric acid, UAR, UCR, and UHR levels of obese adolescents were significantly higher than the healthy group (p < 0.05). We found that HOMA-IR was positively correlated with uric acid, UAR, and UHR. No correlation was found between BMI and uric acid or uric acid-related ratios. We did not find any difference between the two groups in terms of ULR levels, and we did not find any correlation between BMI and HOMA-IR.

CONCLUSION

High levels of serum uric acid, UAR, UCR, and UHR were associated with obesity. Furthermore, we found that uric acid, UAR, and UHR were positively correlated with insulin resistance.

Serum uric acid to creatinine ratio and metabolic syndrome in middle-aged and elderly population: Based on the 2015 CHARLS

BACKGROUND AND AIMS

Serum uric acid to creatinine ratio (SUA/Cr) may be associated with metabolic syndrome (MS). Here, we investigated the correlation between SUA/Cr and MS in Chinese residents aged ≥ 45 years.

METHODS AND RESULTS

Data were obtained from the 2015 China Health and Retirement Longitudinal Study (CHARLS) database. MS was diagnosed using the Chinese Diabetes Society 2017 criteria. We grouped the population according to SUA/Cr quartiles and compared the index differences between groups. We used spearman correlation analysis and binary logistic regression. The possible dose-response association of SUA/Cr with MS were analyzed using restricted cubic spline model. Of 12,946 included participants, 3370 (26.0%) had MS, and 1900 (56.4%) were female. After adjusting for multiple confounders, binary logistic regression analysis showed that compared with Quartile 1, the odds ratio (95% confidence interval) of the MS risk was 1.29 (1.09-1.52), 1.47 (1.25-1.74), and 1.80 (1.53-2.12) in Quartiles 2, 3, and 4, respectively. The restricted cubic spline model indicated a significant nonlinear dose-response association (P_overall < 0.001, P_{non-linearity} = 0.029) between SUA/Cr and strength of MS prevalence association; MS risk began increasing when SUA/Cr > 6.22.

CONCLUSIONS

A significant positive correlation existed between SUA/Cr and MS risk in Chinese individuals aged ≥ 45 years, which may be a new predictive marker for MS risk.

Serum Uric Acid Levels Are Associated with the Echogenic Features of Carotid Plaque Vulnerability in Elderly Patients with Atherosclerotic Disease

Uric acid is a marker of inflammation and a risk factor for atherosclerosis that has been suggested to play a role in carotid plaque instability. Reduced atherosclerotic plaque echogenicity at ultrasound examination is associated with alarming histopathological features and inflammation. In this study, we investigated the relationship between serum uric acid (SUA) levels and echogenic patterns of plaque instability in elderly subjects with carotid atherosclerosis. Since uric acid metabolism largely depends on renal function, SUA levels were indexed for serum creatinine levels (SUA/SCr). We enrolled 108 patients aged 65 years or more (72.7 ± 5.9 years; 50 females and 58 males) who underwent carotid duplex ultrasound to evaluate plaque echogenicity by greyscale median (GSM). The regression analysis demonstrated a significant inverse association between the GSM and the SUA/SCr ratio (β: -0.567; 95% CI -0.751 to -0.384 and p < 0.0001). Stepwise multivariate regression showed that the SUA/SCr ratio explained 30.3% of GSM variability (β: -0.600; 95% CI -0.777/-0.424, p < 0.0001, and semi-partial correlation 0.303). After a mean period of 3.5 ± 0.5 years, 48 patients were reevaluated according to the same baseline study protocol. The regression analysis demonstrated a still significant inverse association between the GSM and the SUA/SCr ratio (β: -0.462; 95% CI -0.745 to -0.178 and p = 0.002). Stepwise multivariate regression showed that the SUA/SCr ratio explained 28.0% of GSM variability (coefficient -0.584, 95% CI -0.848/-0.319, p < 0.0001, and semi-partial R² 0.280). In conclusion, this study demonstrates that SUA levels indexed for serum creatinine are associated with the echogenic features of carotid plaque vulnerability in elderly patients with atherosclerotic disease. These data could suggest an influential role for uric acid metabolism in carotid plaque biology.

Uric acid level in climacteric women and its association with clinical and metabolic parameters

Climacteric women often experience unfavorable metabolic changes. Consequently, identifying markers that may contribute to such undesirable changes is imperative. This study aimed to evaluate serum uric acid (UA) concentration and its association with metabolic and clinical parameters in climacteric women. We selected 672 women between 40 and 65 years and performed interviews, biochemical analyses, blood pressure, and anthropometric measurements. UA levels were determined using the enzymatic-colorimetric method. We compared variables according to the quartiles of UA using the Kruskal-Wallis test. The mean UA level was 4.9 ± 1.5 mg/dl, ranging from 2.0 to 11.6 mg/dl. We found that UA levels greater than 4.8 mg/dl were associated with adverse metabolic parameters in climacteric women. For all anthropometric and biochemical variables, we observed significantly better results in women who had lower UA levels (p < 0.05). Similarly, we observed a significant increase in blood pressure, frequency of metabolic syndrome, and cardiovascular risk as UA levels increased (p < 0.05). Our findings showed that climacteric women with high levels of UA were more likely to have adverse metabolic and clinical parameters than those with lower UA levels. Further studies may determine the causal relationship between UA and metabolic changes in climacteric women.

Serum uric acid: creatinine ratio (UCR) is associated with recurrence of atrial fibrillation after catheter ablation

Background and aims

Studies showed that elevated preoperative serum uric acid(SUA) levels are associated with recurrence of atrial fibrillation(AF) after catheter ablation. UA:creatinine ratio(UCR - UA normalised for renal function) has appeared as a new biomarker and is considered to reflect endogenous UA levels preferably because it eliminates the influence of renal function. This study aimed to investigate the correlation between UCR and recurrence of AF after catheter ablation.

Methods and results

A total of 233 consecutive patients with symptomatic, drug-refractory AF underwent catheter ablation. All participants underwent history-taking, physical examination and blood biochemistry analysis at baseline. After a mean follow-up of 23.99 ± 0.76 months, recurrence ratios for each UCR quartile (from lowest quartile to highest) were 10.9%, 23.6%, 23.6%, and 41.8%, respectively (P = 0.005). Multivariate Cox regression analysis revealed that UCR was an independent predictor of AF recurrence (HR 1.217, 95%CI 1.008-1.468; P = 0.041). Subgroup analysis showed that UCR was associated with AF recurrence in paroxysmal AF (HR 1.426, 95% CI 1.092-1.8608; P = 0.009) and in male patients (HR 1.407, 95% CI 1.015-1.950; P = 0.04). A cut-off point of 4.475 for the UCR had sensitivity of 65.5% and specificity of 59.6% in predicting AF recurrence (P = 0.001).

Conclusion

Our results demonstrate that elevated preoperative UCR is associated with recurrence of AF after catheter ablation, and it indicate UCR maybe a predictive factor for the recurrence of AF.

Exposure to Cadmium, Lead, Mercury, and Arsenic and Uric Acid Levels: Results from NHANES 2007-2016

Mechanisms underlying abnormal uric acid (UA) levels from exposure to toxic metals/metalloids have not been not fully elucidated, especially in the context of mixtures. The aim was to identify major toxic metals/metalloids that affected UA levels with a mixture exposure concept in the association model. From 2007-2016 National Health and Nutrition Examination Survey (NHANES), 4794 adults were involved. Serum UA (SUA) and SUA to serum creatinine ratio (SUA/SCr) were used to estimate the UA levels, and cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As) in the blood and/or urine were evaluated in the study. We assessed the associations between toxic metals and UA levels using linear regression and Bayesian kernel machine regression (BKMR). The median [P₂₅, P₇₅] SUA/SCr and SUA level were 6.22 [5.27, 7.32] and 0.83 [0.72, 0.98], respectively. There was no difference for SUA/SCr by gender (men, 6.25 [5.39, 7.29]; women, 6.17 [5.17, 7.36], P = 0.162), but men had higher SUA than women (men, 0.95 [0.85, 1.05]; women, 0.72 [0.64, 0.82], P < 0.001). Blood Pb (β_men = 0.651 and β_women = 1.014) and urinary Cd (β_men = 0.252 and β_women = 0.613) were positively associated with SUA/SCr, and urinary Pb (β_men =  - 0.462 and β_women =  - 0.838) was inversely associated with SUA/SCr in multivariate linear regression analysis. However, urinary As (β_men = 0.351) was positively associated with SUA/SCr only in men. BKMR showed that higher concentrations of exposure to a mixture of toxic metals were positively associated with higher UA levels, where Cd, Pb, and urinary As contributed most to the overall mixture effect in men, while Pb and urinary Cd in women. Our study provided the first evidence that mixtures of metals are associated with the UA levels. Increased concentrations of metals, mainly blood Pb, urinary Cd, and As (only in men) may increase the level of UA.

Serum uric acid to creatinine ratio is a useful predictor of all-cause mortality among hypertensive patients

BACKGROUND

Many of the existing research studies have shown that serum uric acid (SUA) is a predictor of renal disease progression. More recently, studies have suggested an association between renal function-normalized SUA and all-cause mortality in adults. This study aims to examine the association between the ratio of SUA to creatinine (SUA/Cr) and all-cause mortality with a focus on hypertensive patients.

METHODS

This study is based on 2,017 participants, of whom 916 were male (mean age, 67 ± 11 years) and 1,101 were female (mean age, 69 ± 9 years). All participants were part of the Nomura Cohort Study in 2002 (cohort 1) and 2014 (cohort 2), as well as the follow-up period (2002 follow-up rate, 94.8%; 2014 follow-up rate, 98.0%). We obtained adjusted relative risk estimates for all-cause mortality from a basic resident register. In addition, we employed a Cox proportional hazards model and adjusted it for possible confounders to determine the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Of the total participants, 639 (31.7%) were deceased; of these, 327 (35.7%) were male and 312 (28.3%) were female. We found an independent association between a higher ratio of SUA/Cr and a higher risk of all-cause mortality in female participants only (HR, 1.10; 95% CI, 1.02-1.18). The multivariable-adjusted HRs (95% CI) for all-cause mortality across quintiles of baseline SUA/Cr were 1.28 (0.91-1.80), 1.00, 1.38 (0.95-1.98), 1.37 (0.94-2.00), and 1.57 (1.03-2.40) for male participants, and 0.92 (0.64-1.33), 1.00, 1.04 (0.72-1.50), 1.56 (1.06-2.30), and 1.59 (1.06-2.38) for female participants. When the data were further stratified on the basis of age (< 65 or ≥ 65 years), body mass index (< 22.0 or ≥ 22.0 kg/m²), estimated glomerular filtration rate (< 60 or ≥ 60 mL/min/1.73 m²), and presence of SUA-lowering medication, trends similar to those of the full population were found in all groups.

CONCLUSION

Baseline SUA/Cr is independently and significantly associated with future all-cause mortality among hypertensive patients.

Association between serum uric acid/serum creatinine ratios and lung function in the general American population: National Health and Nutrition Examination Survey (NHANES), 2007-2012

BACKGROUND

Assessment of lung function is essential for the early screening chronic airway diseases (CADs). Nevertheless, it is still not widely used for early diagnosing CADs in epidemiological or primary care settings. Thus, we used data from the US National Health and Nutrition Examination Survey (NHANES) to discuss the relationship between the serum uric acid/serum creatinine (SUA/SCr) ratio and lung function in general adults to gain the role of SUA/SCr in early assessment of lung function abnormalities.

METHODS

From 2007 to 2012 NHANES, a total of 9569 people were included in our study. Using the regression model, XGBoost algorithm model, generalised linear model and two-piecewise linear regression model, the link between the SUA/SCr ratio and lung function was investigated.

RESULTS

After correcting for confounding variables, the data revealed that forced vital capacity (FVC) declined by 47.630 and forced expiratory volume in one second (FEV1) decreased by 36.956 for each additional unit of SUA/SCr ratio. However, there was no association between SUA/SCr and FEV1/FVC. In the XGBoost model of FVC, the top five most important were glycohaemoglobin, total bilirubin, SUA/SCr, total cholesterol and aspartate aminotransferase, whereas in FEV1, were glycohaemoglobin, total bilirubin, total cholesterol, SUA/SCr and serum calcium. In addition, we determined the linear and inverse association between SUA/SCr ratio and FVC or FEV1 by constructing a smooth curve.

CONCLUSIONS

In the general American population, the SUA/SCr ratio is inversely linked with FVC and FEV1, but not with FEV1/FVC, according to our research. Future studies should investigate the impact of SUA/SCr on lung function and identify possible mechanisms of action.

Serum uric acid / serum creatinine ratio as a predictor of cardiovascular events. Detection of prognostic cardiovascular cut-off values

OBJECTIVE

In the frame of the Uric Acid Right for Heart Health (URRAH) study, a nationwide multicenter study involving adult participants recruited on a regional community basis from all the territory of Italy under the patronage of the Working Group on Uric Acid and Cardiovascular Risk of the Italian Society of Hypertension, we searched for the cut-off values of the ratio between serum uric acid (SUA) and serum creatinine (sCr) able to predict cardiovascular (CV) events.

METHODS

Among 20 724 participants followed-up for 126 ± 64 months, after detecting cut-off by the receiver operating characteristic curves, we calculated by Cox models adjusted for confounders having CV events as dependent variable the hazard ratio (HR) of SUA/sCr > cut-off. We also verified if the role of cut-off varied with increasing SUA/sCr.

RESULTS

A plausible prognostic cut-off of SUA/sCr was found and was the same in the whole database, in men and in women (>5.35). The HR of SUA/sCr > cut-off was 1.159 (95% confidence interval [CI] 1.092-1.131, P < 0.03) in all, 1.161 (95% CI 1.021-1.335, P < 0.02) in men, and 1.444 (95% CI 1.012-1.113, P < 0.03) in women. In increasing quintiles of SUA/sCr the cut-offs were >3.08, >4.87, >5.35, >6.22 and >7.58, respectively. The HRs significantly increased from the 3rd to the 5th quintile (1.21, 95% CI 1.032-1.467, P = 0.018; 1.294, 95% CI 1.101-1.521, P = 0.002; and 1.642, 95% CI 1.405-1.919, P < 0.0001; respectively), that is, over 5.35, whereas the 2nd quintile was not significantly different from the 1st (reference).

CONCLUSION

Having SUA/sCr >5.35 is an independent CV risk indicator both in men and women. The cut-off is dynamic and significantly increases with increasing SUA/sCr.

Association between metabolic syndrome and uric acid: a systematic review and meta-analysis

This systematic review and meta-analysis aim to provide the best evidence on the association between metabolic syndrome (MetS) and uric acid (UA) by determining the size of the effect of this biomarker on MetS. The review protocol is registered with PROSPERO (CRD42021231124). The search covered the PubMed and Scopus databases. Methodological quality was assessed with the STROBE tool, overall risk of bias with RevMan (Cochrane Collaboration) and quality of evidence with Grade Pro. Initially, 1582 articles were identified. Then, after excluding duplicates and reviewing titles and abstracts, 1529 articles were excluded from applying the eligibility criteria. We included 43 papers (56 groups) comparing UA concentrations between subjects 91,845 with MetS and 259,931 controls. Subjects with MetS had a higher mean UA of 0.57 mg/dl (95% CI 0.54-0.61) (p < 0.00001). Given the heterogeneity of the included studies, the researchers decided to perform subgroups analysis. Men with MetS have a higher UA concentration mg/dl 0.53 (95% CI 0.45-0.62, p < 0.00001) and women with MetS 0.57 (95% CI 0.48-0.66, p < 0.00001) compared to subjects without MetS. Assessment of UA concentration could provide a new avenue for early diagnosis of MetS, as a new biomarker and the possibility of new therapeutic targets.

Association between serum uric acid to serum creatinine ratio and poor functional outcomes in patients with acute ischemic stroke

BACKGROUND

The role of serum uric acid (SUA) in prognosis is controversial because SUA levels largely depend on renal clearance function. This study aimed to investigate the association between renal function-normalized SUA (SUA to serum creatinine ratio, SUA/SCr) and poor functional outcomes in patients with acute ischemic stroke (AIS).

METHODS

All patients were recruited from the Third China National Stroke Registry. Poor functional outcomes were defined by modified Rankin Scale (mRS) scores of 3-6 at 3 months or 2-6 at 1 year.

RESULTS

Among 8169 enrolled patients, the median SUA/SCr was 4.19 (interquartile range, 3.47-5.08). Compared with patients in the fourth quintile group, those in the first quintile group had higher proportions of mRS score 3-6 (odds ratio [OR] 1.55; 95% confidence interval [CI] 1.24-1.93) and mRS score 2-6 (OR 1.28; 95% CI 1.08-1.53) at 3 months. The addition of SUA/SCr to the conventional risk model had a greater incremental value than the addition of SUA or SCr alone. Subgroup analysis showed that the association was only significant in patients with normal kidney function (P for interaction<0.05). Similar results were found for outcomes at 1 year.

CONCLUSIONS

A lower level of SUA/SCr was associated with poor functional outcomes in patients with AIS at 3 months and at 1 year, suggesting the potential use of SUA/SCr in clinical practice as a preferable marker for stroke outcomes.

The association between the serum uric acid to creatinine ratio and all-cause mortality in elderly hemodialysis patients

BACKGROUND

Elderly hemodialysis patients have a higher rate of mortality than nonelderly hemodialysis patients. Recent studies shown that the serum uric acid to creatinine ratio (SUA/Scr) was associated with all-cause mortality in general adults. The purpose of the present study was to investigate the association between the SUA/Scr and all-cause and cardiovascular disease mortality among elderly hemodialysis patients.

METHODS

A total of 222 patients (≥ 60 years) who received hemodialysis more than 8 h per week at Taizhou Second People's Hospital for at least 3 months were enrolled in the present study from January 2015 to December 2019. Clinical characteristics including age, sex and height et. al, were obtained from the hemodialysis database. The laboratory data, including albumin (ALB), total cholesterol (TC), serum uric acid (SUA), serum creatinine (Scr) and so on, were collected before hemodialysis and analyzed by automatic biochemical analyzer. Survival information was recorded during the follow-up period. Multiple Cox regression was carried out to analyze the association between SUA/Scr and all-cause mortality. The survival rate of each group was calculated by the Kaplan-Meier method, and the ratio of survival curves was analyzed by the log-rank test. The contribution of SUA/Scr for predicting all-cause mortality risk was evaluated by net reclassification improvement (NRI).

RESULTS

During the 19-month observation period, 78 patients died. Individuals in the nonsurviving group had significantly older ages (P < 0.001), body mass index (BMI) (P = 0.004), serum creatinine (P = 0.005) and prealbumin (P = 0.006) than surviving patients. After adjusting for age, sex, BMI, prealbumin, dialysis vintage, dialysis frequency, single-pool Kt/V (spKt/V), DM, hypertension and comorbidities, a higher ratio of SUA/Scr was independently associated with a higher risk of all-cause mortality (HR: 1.292; 95% CI: 1.013-1.648; P = 0.039). The predict value on all-cause mortality of SUA/Scr was superior to SUA (additive NRI = 0.214, P = 0.015) and Scr (additive NRI = 0.476, P < 0.001) among elderly hemodialysis patients.

CONCLUSION

The serum uric acid to creatinine ratio is strongly associated with all-cause mortality in elderly hemodialysis patients which is more predictive than SUA or Scr alone.

The Diagnostic Role of Uric Acid to Creatinine Ratio for the Identification of Patients with Adverse Pulmonary Embolism Outcomes

Background: Uric acid (UA) is the final product of purine metabolism and a marker of oxidative stress that may be involved in the pathophysiology of cardiovascular and thromboembolic disease. The aim of the current study is to investigate the potential value of UA to creatinine ratio (UA/Cr) as a diagnostic tool for the outcome of patients admitted with acute pulmonary embolism (PE) and the correlations with other parameters. Methods: We evaluated 116 patients who were admitted for PE in a respiratory medicine department. PE was confirmed with computed tomography pulmonary angiography. Outcomes evaluated were hospitalization duration, mortality or thrombolysis and a composite endpoint (defined as mortality or thrombolysis). Patients were assessed for PE severity with the PE Severity Index (PESI) and the European Society of Cardiology (ESC) 2019 risk stratification. Results: The median (interquartile range) UA/Cr level was 7.59 (6.3–9.3). UA/Cr was significantly associated with PESI (p < 0.001), simplified PESI (p = 0.019), and ESC 2019 risk stratification (p < 0.001). The area under the curve (AUC) for prediction of 30-day mortality by UA/Cr was 0.793 (95% CI: 0.667–0.918). UA/Cr levels ≥7.64 showed 87% specificity and 94% negative predictive value for mortality. In multivariable analysis UA/Cr was an independent predictor of mortality (HR (95% CI): 1.620 (1.245–2.108), p < 0.001) and composite outcome (HR (95% CI): 1.521 (1.211–1.908), p < 0.001). Patients with elevated UA/Cr levels (≥7.64) had longer hospitalization (median (IQR) 7 (5–11) vs. 6 (5–8) days, p = 0.006)), higher mortality (27.3% vs. 3.2%, p = 0.001) and worse composite endpoint (32.7% vs. 3.4%, p < 0.001). Conclusion: Serum UA/Cr ratio levels at the time of PE diagnosis are associated with disease severity and risk stratification, and may be a useful biomarker for the identification of patients at risk of adverse outcomes.

Uric acid and uric acid/creatinine ratio and their correlations with the hemorheological determinants in subjects with subclinical carotid atherosclerosis

BACKGROUND AND OBJECTIVE

we have examined the concentration of serum uric acid and the serum uric acid/creatinine ratio as well as their correlations with the main determinants of the hemorheological profile in a group of subjects with subclinical carotid atherosclerosis.

METHODS

we evaluated the concentration of serum uric acid and the serum uric acid/creatine ratio in 43 men and 57 women [median age 66.00 (25)] with subclinical carotid atherosclerosis, subsequently divided according to the number of traditional cardiovascular risk factors and to the insulin resistance degree.

RESULTS

serum uric acid, but not the serum uric acid/creatinine ratio, results strongly influenced by the number of cardiovascular risk factors and by the insulin resistance degree. In the whole group and in the subgroups of subclinical carotid atherosclerosis subjects, serum uric acid and serum uric acid/creatinine ratio show significant correlation, besides with whole blood viscosity, with plasma viscosity and erythrocyte aggregation. The influence of the serum uric acid on the erythrocyte aggregability that is a part of the erythrocyte aggregation is to ascribe to the action carried out by serum uric acid on the erythrocyte zeta potential.

CONCLUSIONS

it is reasonable to think that the treatment of the asymptomatic or symptomatic hyperuricemia with the urate-lowering therapy that reduces the serum uric acid concentration may reflect on the hemorheological profile which role on the atherosclerotic cardiovascular disease is well known.

The Serum Uric Acid to Serum Creatinine Ratio is an Independent Risk Factor for Diabetic Kidney Disease

PURPOSE

A retrospective study was designed to evaluate whether the serum uric acid to serum creatinine ratio (SUA/SCr) can be used as an indicator of diabetic kidney disease (DKD) and macroangiopathy in patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

We screened 2227 patients diagnosed with T2DM, and 450 patients were finally included. They were assigned to three groups based on the tertile of SUA/SCr (Group Tertile 1, Tertile 2, Tertile 3). Demographic information and biochemical parameters were collected from Electronic Patient Record (EPR).

RESULTS

The estimated glomerular filtration rate (eGFR) values were lowest in Group Tertile 1 and highest in Group Tertile 3 (P < 0.05). There was no significant difference in urinary albumin creatinine ratio (UACR) among the three groups (P > 0.05). Partial correlation analyses revealed that SUA/SCr levels were significantly and positively correlated with eGFR, SUA, body mass index, gamma-glutamyl transpeptidase, alanine transaminase, triglycerides, C-peptide, high-density lipoprotein cholesterol and fatty liver, while they were negatively correlated with SCr, blood urea nitrogen, cystatin-c, age, male sex, DM duration and hypertension history (P < 0.05). Logistic regression analysis revealed that SUA/SCr was an independent risk factor for eGFR < 60 mL/min/1.73 m² (P < 0.05). The ROC curve showed that the cutoff value of SUA/SCr for the identification of eGFR < 60 mL/min/1.73 m² was 3.434. In patients with normal UACR, SUA/SCr levels of patients with eGFR < 60 mL/min/1.73 m² were lower than those with eGFR ≥ 60 mL/min/1.73 m² (P < 0.05). Regression analysis did not show SUA/SCr associate to macrovascular disease after adjusting for confounding factors.

CONCLUSION

SUA/SCr is an independent risk factor for DKD in patients with T2DM and may be helpful for identifying normoalbuminuric DKD.

Association of the serum uric acid to creatinine ratio with metabolic syndrome in the middle age and older population in China

BACKGROUND

Metabolic syndrome (MetS) has attracted great interest, with an increasing prevalence. Recent studies have shown that the serum uric acid-to-creatinine ratio (SUACr) might be an excellent biomarker for MetS risk prediction in diabetic patients and postmenopausal women. However, the relationship between SUACr and MetS in a middle-aged and older population remains unclear.

METHODS

A total of 1277 participants were included in this cross-sectional study. Logistic regression modelling was performed to assess the association between SUACr and MetS in the total population. The dose-response relationship of SUACr and MetS was further assessed by a restricted cubic spline model (RCS). Furthermore, to explore the relationships between the levels of SUACr and the number of metabolic components, analysis of covariance (ANCOVA) was applied.

RESULTS

The levels of SUACr were lower in the non-MetS participants (OR 1.60, 95% CI 1.36 to 1.89; P<0.001),. Positive and dose-response relationships were further confirmed by the RCS model. We also found that, with increased number of components, the SUACr tended to increase. Moreover, values of SUACr were strongly related to levels of triglycerides (TGs), body mass index (BMI), blood glucose levels, systolic blood pressure/diastolic blood pressure (SBP/DBP), and hypertension. In addition, the positive association between SUACr and MetS also occurred in those patients with normal uric acid levels.

CONCLUSION

Elevated values of SUACr were strongly associated with an increased risk of MetS; this positive relationship remained in those individuals with normal uric acid levels.

Metabolic Factors Mediate the Association Between Serum Uric Acid to Serum Creatinine Ratio and Cardiovascular Disease

Background

The serum uric acid/serum creatinine ratio (SUA/SCr), which represents renal function‐normalized SUA, is associated with diverse adverse outcomes. The aim of this study was to investigate the association between SUA/SCr and cardiovascular disease (CVD), and determine whether and to what extent this association is mediated by cardiometabolic factors.

Methods and Results

This prospective study enrolled 96 378 participants from the Kailuan study without stroke and myocardial infarction at baseline (2006). Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Mediation analyses were conducted to separately explore the mediating effects of cardiometabolic factors on the association between SUA/SCr and CVD. During median follow up of 11.01 years, 6315 (6.55%) individuals developed incident CVD. After adjustment for potential confounders, the highest quartile of SUA/SCr was associated with the highest risk of CVD (HR, 1.15; 95% CI, 1.07–1.23), stroke (HR, 1.16; 95% CI, 1.07–1.26), ischemic stroke (HR, 1.12; 95% CI, 1.02–1.22), and hemorrhagic stroke (HR, 1.36; 95% CI, 1.11–1.65), but not with myocardial infarction (HR, 1.07; 95% CI, 0.92–1.25). The association was consistent across different degrees of kidney function and glucose tolerance statuses. Additionally, the association between high SUA/SCr and CVD was partially mediated by triglycerides (30.74%), body mass index (BMI) (19.52%), total cholesterol (15.06%), hs‐CRP (high‐sensitivity C‐reactive protein) (13.06%), diastolic blood pressure (11.75%), and blood glucose (−16.38%).

Conclusions

SUA/SCr and CVD were positively associated. Furthermore, this association was partially mediated through blood lipids, BMI, blood pressure, hs‐CRP, and blood glucose.

Association of uric acid and uric acid to creatinine ratio with chronic kidney disease in hypertensive patients

Background

Recent studies have shown that the serum uric acid/creatinine ratio (SUA/SCr) is a better predictor of chronic kidney disease (CKD) than serum uric acid (SUA) isolated. The aim of the present study was to evaluate the association of isolated SUA and the SUA/SCr with CKD in hypertensive patients.

Methods

Cross-sectional study conducted with hypertensive patients followed-up by the Primary Health Care Service (PHC). Sociodemographic, economic, lifestyle, clinical, anthropometric, and biochemical variables were evaluated. The association between SUA parameters (quartiles of SUA and quartiles of SUA/SCr) and CKD was evaluated by bivariate and multivariate logistic regression. The association between SUA parameters (SUA and SUA/SCr) and estimated glomerular filtration rate (eGFR) was evaluated by linear regression. The analyses were performed considering four adjustment models. SUA and SUA/SCr were compared by receiver operating characteristic (ROC) curve.

Results

In the fully adjusted model, SUA was positively associated with the presence of CKD (OR = 6.72 [95 % CI 1.96–22.96]) and inversely associated with eGFR (β Coef. = -2.41 [95 % CI -3.44; -1.39]). SUA/SCr was positively associated with eGFR (β Coef. = 2.39 [1.42; 3.36]). According to the ROC curve, the SUA is a better predictor of CKD than the SUA/SCr.

Conclusions

Elevated levels of isolated SUA were associated with CKD and eGFR. However, the SUA/SCr was not associated with CKD. We do not recommend using the SUA/SCr to predict CKD in hypertensive patients.