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.

Prospective urinary albumin/creatinine ratio for diagnosis, staging, and organ response assessment in renal AL amyloidosis: results from a large cohort of patients

Objectives Quantification of 24 h-proteinuria is the gold standard for diagnosing, staging, and monitoring of patients with renal AL amyloidosis. However, 24 h-urine collection is cumbersome and may result in preanalytical error. In this prospective study, we investigated the role of urinary albumin/creatinine ratio (UACR) (cut-off: 300 mg/g) identifying renal involvement, evaluated a UACR-based staging system (UACR cut-off: 3,600 mg/g) and assessed whether UACR response (UACR decrease >30% without worsening in eGFR >25%) predicts renal outcome in 531 patients with newly-diagnosed AL amyloidosis. Methods From October 2013 paired 24 h-proteinuria and UACR (on first morning void) were measured in all newly-diagnosed patients with AL amyloidosis. Correlation between 24 h-proteinuria and UACR at baseline was assessed by Pearson’s r test. Impact of UACR response on renal outcome was assessed in randomly created testing (n=354) and validation (n=177) cohorts. Results A strong linear correlation was found between 24 h-proteinuria and UACR at baseline (r=0.90; p<0.001). After a median follow-up of 31 months, 57 (11%) patients required dialysis. A UACR-based renal staging system identified three stages with significantly higher dialysis rate at 36 months comparing stage I with stage II and stage II with stage III. Achieving a renal response, according to a UACR-based criterion, resulted in lower dialysis rate in both testing and validation cohorts. Conclusions UACR is a reliable marker for diagnosis, prognosis, and organ response assessment in renal AL amyloidosis and can reliably replace 24 h-proteinuria in clinical trials and individual patients’ management.

The Effect of Diabetes and the Diabetogenic TBC1D4 p.Arg684Ter Variant on Kidney Function in Inuit in Greenland

ObjectiveDiabetes prevalence in Greenland is high and increasing. The aim of this study was to examine the effect of diabetes and the diabetogenic TBC1D4 variant on kidney function in Greenland in a population-based setting.Research Design and MethodsHealth survey data and TBC1D4 genotypes from 5,336 Greenlanders was used to estimate odds ratios (ORs) of albuminuria (>30 mg/g creatinine) and chronic kidney disease (CKD, eGFR<60 ml/min/1.73m2), comparing individuals with and without diabetes. Using baseline and follow-up data from individuals who participated in two surveys we examined the effect of diabetes on eGFR and urinary albumin creatinine ratio (UACR) at follow-up, stepwise adjusting for baseline confounders including the TBC1D4 variant.ResultsA total of 9.3% had diabetes of the 3,909 participants with complete data. Albuminuria and CKD was found in 27.6% and 9.5% among those with and without diabetes respectively. Diabetes was associated with increased risk of albuminuria (OR(95% CI) = 2.37 (1.69,3.33) p<0.001) and the TBC1D4 variant protected against albuminuria (OR(95% CI) = 0.44 (0.22,0.90) p=0.02) in a multivariable model. Neither diabetes nor the TBC1D4 variant significantly associated with CKD. Diabetes was not associated with changes in eGFR or UACR over a median of 11.3 years.ConclusionDiabetes conferred increased risk of albuminuria and the TBC1D4 variant was associated with decreased risk of albuminuria, but neither were associated with CKD. The presence/absence of diabetes did not predict changes in eGFR and UACR in longitudinal analyses. The potential renoprotective association of the TBC1D4 variant on albuminuria calls for further studies.

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 relationship between urinary albumin to creatinine ratio and all-cause mortality in the elderly population in the Chinese community: a 10-year follow-up study

Background In patients with diabetes and hypertension, proteinuria is independently associated with all-cause death. However, in the general population, urinary albumin to creatinine ratio (UACR) is less used to predict all-cause mortality. When the urinary albumin to creatinine ratio is within the normal range (UACR< 30 mg/g), the clinical relevance of an increased urinary albumin excretion rate is still debated. We studied the relationship between UACR and all-cause mortality in community populations, and compared UACR groups within the normal range. Methods The participants were the inhabitants from the Wanshoulu community in Beijing, China. The average age is 71.48 years, and the proportion of women is 60.1%. A total of 2148 people completed random urine samples to determine the urinary albumin to creatinine ratio (UACR). The subjects were divided into three groups according to UACR: Group 1 (UACR< 10 mg/g), Group 2 (10 mg/g < UACR< 30 mg/g), Group 3 (UACR> 30 mg/g). We used Kaplan-Meier survival analysis and Cox regression model to verify the relationship between UACR and all-cause mortality. Results At an average follow-up of 9.87 years (718,407.3 years), the total mortality rate were 183.4/1000. In the Cox proportional hazards model, after adjusting for possible confounders, those with normal high-value UACR (group 2) showed a higher all-cause mortality than those with normal low-value UACR (group 1) [hazard ratio (HR) 1.289, 95% confidence interval (CI) 1.002 ~ 1.659 for all-cause mortality]. Those with proteinuria (group 3) showed a higher all-cause mortality than those with normal low-value UACR (group 1) [hazard ratio (HR) 1.394, 95% confidence interval (CI) 1.020 ~ 1.905 for all-cause mortality]. Conclusion Urinary albumin to creatinine ratio is an important risk factor for all-cause death in community population. Even if it is within the normal range (UACR< 30 mg/g), it occurs in people with high normal value (10 mg/g < UACR< 30 mg/g), the risk of all-cause death will also increase.

Spot Urine Uric Acid to Creatinine Ratio used in the Estimation of Hyperuricosuria in the Young Korean Population

Background: Uric acid levels in urine are measured using urine specimens 24 hours or by uric acid glomerular filtration rate (UAGFR) with spot urine, which additionally requires a blood sample. This study aimed to investigate whether urinary uric acid creatinine ratio (UUACr) obtained by spot urine alone could be recognized as a substitute for UAGFR value, and hyperuricosuria can be screened by UUACr. UUACr is known to vary with age and regional differences. This study focused on the reference value of each value in Korean young populations.Method: We enrolled Korean subjects 1–20 years with normal kidney function, from a single hospital, classified into 5 age groups, 1–5 years, 6–8 years, 9–12 years, 13–15 years, and 16–20 years. We checked spot urine uric acid, creatinine and serum uric acid, creatinine levels on the same day from February 2014 to December 2018. We measured the average of UAGFR and UUACr in each groups. The UUACr cut-off value of the upper 2 standard deviation (SD) of UAGFR were taken.Results: The upper 2 SD of UUACr (mg/mg) and UAGFR (mg/dL) were determined in all age groups. UUACr decreased with grown up (P=0.000), but UAGFR were not statistically different among the groups. UUACr and UAGFR were not significantly different by gender. UUACr and UAGFR were positively correlated; UUACr cut-off value of upper 2 SD UAGFR (0.54 mg/dL) was 0.65 mg/mg in total age.Conclusions: UUACr could potentially be used to screen for hyperuricosuria.