Association of renal manifestations with serum uric acid in Korean adults with normal uric acid levels

A Cohort Study on the Correlation Between Serum Uric Acid Trajectory and New-Onset Hypertension Based on Longitudinal Health Examination Data in Henan Area

OBJECTIVE

To explore the correlation between serum uric acid (SUA) trajectories and new-onset hypertension, to provide scientific basis for the prevention and treatment of hypertension.

METHODS

The study cohort was composed of 4372 subjects who met the inclusion criteria in the cohort study of Henan physical examination population. According to the SUA values of the subjects' physical examination from 2017 to 2019, three different SUA trajectory groups were determined by R LCTM tools, namely low stability group, medium stability group and high stability group. The incidence of hypertension during physical examination in 2020 was followed up, the cumulative incidence rate in each group was calculated by product limit method, and the correlation between different SUA trajectories and new-onset hypertension was analyzed by Cox proportional hazards regression model.

RESULTS

The incidence rate of hypertension increased with the increase of SUA locus, which was 4.65%, 9.18% and 12.43% respectively, and the difference was statistically significant (P<0.001). After adjusting multiple confounding factors, such as gender, waist circumference (WC), blood pressure, body mass index (BMI), fasting plasma glucose (FPG) and blood lipid by Cox proportional hazards regression model, the risk of hypertension in SUA medium stability and high stability group was still 1.476 times (95% CI: 1.089~2.000) and 1.692 times (95% CI: 1.152~2.484) of low-stable SUA group (P<0.05).

CONCLUSION

The risk of hypertension increases with the increase of SUA level in the long-term normal range. It is necessary to carry out the intervention for hypertension with long-term normal high value to avoid the progress of hypertension disease, to achieve the purpose of early prevention of hypertension.

The clinicopathological features and renal prognostic factors in pure membranous lupus nephritis-a large series cohort study from China

BACKGROUND

Membranous lupus nephritis (MLN) is a subepithelial immune deposition or its morphological sequelae with or without mesangial changes. Previous studies on the prognosis of MLN have shown relatively small sample sizes and short follow-up periods.

METHODS

Our study was a retrospective analysis of biopsy-proven MLN patients from January 2010 to January 2020 at Jinling Hospital in China. The clinical manifestations, pathological features, and renal outcomes of MLN patients were collected. The endpoint was defined as end-stage kidney disease (eGFR≤15 mL/min·1.73 m2 or need for renal replacement therapy) or a doubling of serum creatinine or an eGFR decline of more than 40%. We used Cox regression to analyze the risk factors for renal outcome and Kaplan-Meier curves were used to analyze renal survival rate.

RESULTS

In the total of 2884 lupus patients, we screened 535 MLN patients. 456 MLN patients were recruited with an average age of 34 ± 12 years, 87.8% for female patients and 62.1% patients of nephrotic syndrome with proteinuria of 2.67 g/24h. After follow-up of 78 (IQR, 47.3-113.0) months, 37 (8.1%) patients reached the renal endpoint. The 5-year and 10-year renal survival rates were 95.8% and 89.4%, respectively. 370 patients (81.1%) achieved complete remission, 43 patients (9.4%) had partial remission, and only 43 had no response. 34.4% MLN experienced a relapse. The Cox regression showed the risk factors that affect the renal prognosis include male, hypertension history, anemia, high uric acid, acute kidney injury, and interstitial fibrosis in the renal pathology.

CONCLUSIONS

MLN mostly manifested as nephrotic syndrome, with few renal dysfunctions. Although MLN had a high relapse rate, most patients had a response to immunosuppressants and had a good renal outcome.

Uric acid level and kidney function: a cross-sectional study of the Korean national health and nutrition examination survey (2016-2017)

Kidney disease is expected to become the fifth leading cause of premature death globally by 2040. Uric acid level is a risk factor for kidney disease. The current study aims to investigate the association between uric acid levels and kidney function in the Korean population. The data of 11,042 participants of the 2016–2017 Korea National Health and Nutrition Examination Survey were analysed. The estimated glomerular filtration rate was calculated using the modification of diet in renal disease formula for Koreans. For each sex, uric acid levels were divided into five subsequent categories of increasing levels (Q1, Q2, Q3, Q4, and hyperuricemia). The association between uric acid level and kidney function was investigated using multiple logistic regression. The results showed that the higher the uric acid levels, the greater the odds of reduced kidney function in both sexes. In men, the adjusted odds ratios (95% confidence intervals) for reduced eGFR comparing the hyperuricemia group to the lowest serum uric acid quartile was 5.55 (3.27–9.44), and in women, the odds ratios (95% confidence intervals) was 7.52 (4.39–12.87). Normal weight or underweight in men and overweight in women, as well as diabetes mellitus, hypertension, and physical inactivity were highly associated with reduced kidney function. Our study revealed a dose–response relationship between uric acid levels and kidney function. Therefore, high uric acid level should be considered as a factor that is potentially related to kidney dysfunction in the Korean population.

C-Peptide: A Mediator of the Association Between Serum Uric Acid to Creatinine Ratio and Non-Alcoholic Fatty Liver Disease in a Chinese Population With Normal Serum Uric Acid Levels

BACKGROUND

The data on the relationship between normal-ranged serum uric acid (SUA), β-cell function, and non-alcoholic fatty liver disease (NAFLD) are complicated and insufficient. Moreover, uric acid is excreted by kidney, and SUA levels may be affected by renal function. Thus, we introduced a renal function-normalized index [serum uric acid to creatinine ratio (SUA/Cr)] into the study and explored the association between SUA/Cr, C-peptide and NAFLD in a Chinese population with normal SUA levels by a cross-sectional analysis.

MATERIALS AND METHODS

A total of 282 individuals with normal SUA levels and different glucose tolerance status from a diabetes project were included in the study (mean age = 53.7± 10.5 years; women = 64.50%). NAFLD was diagnosed by abdominal ultrasonography (NAFLD, n=86; without NAFLD, n=196). Trapezoid formula was used to calculate area under the curve of C-peptide (AUC_CP) from 4 points (including 0, 30,60, and 120min) during 2-h oral glucose tolerance test. Spearman correlation analysis was used to explore the correlation between SUA/Cr, AUC_CP and NAFLD risk factors. Multiple logistic regression analysis was used to explore the association between SUA/Cr or AUC_CP and NAFLD. Mediation analysis was used to explore whether AUC_CP mediated the association between SUA/Cr and NAFLD.

RESULTS

Individuals with NAFLD had significantly higher SUA/Cr and AUC_CP than those without NAFLD(P<0.05). Spearman correlation analysis showed that both SUA/Cr and AUC_CP were significantly associated with many NAFLD risk factors, and SUA/Cr was positively correlated with AUC_CP (P<0.05). Multiple logistic regression analysis indicated that SUA/Cr and AUC_CP were positively associated with NAFLD incidence (P<0.05). Medication analysis indicated that SUA/Cr had a significant direct effect on NAFLD (β =0.5854, 95% CI: 0.3232-0.8966), and AUC_CP partly mediated the indirect effect of SUA/Cr on NAFLD incidence (β =0.1311, 95% CI: 0.0168-0.4663).

CONCLUSIONS

SUA/Cr was positively associated with NAFLD incidence, and AUC_CP partly mediated the association in a Chinese population with normal SUA levels. Thus, we should pay more attention to high-normal SUA and C-peptide levels due to their predictive power in NAFLD incidence.

Uric Acid Level Has a J-Shaped Association with Arterial Stiffness in Korean Postmenopausal Women

Background

Uric acid has been reported to function both as an oxidant or antioxidant depending on the context. A previous study in the Korean population reported a positive linear association between serum uric acid level and arterial stiffness in men, but little is known about how serum uric acid level is related to the risk of increased arterial stiffness in Korean postmenopausal women.

Methods

We performed a cross-sectional study of 293 subjects who participated in a health examination program run by the health promotion center of Gangnam Severance Hospital between October 2007 and July 2010. High brachial-ankle pulse wave velocity was defined as a brachial-ankle pulse wave velocity of more than 1,450 cm/s. The odds ratios (ORs) for high brachial-ankle pulse wave velocity were calculated using multivariate logistic regression analysis across uric acid quartiles after adjusting for other indicators of cardiovascular risk.

Results

The 293 postmenopausal women were divided into quartiles according to uric acid level. The mean brachial-ankle pulse wave velocity values of each quartile were as follows: Q1, 1,474 cm/s; Q2, 1,375 cm/s; Q3, 1,422 cm/s; Q4, 1,528 cm/s. The second quartile was designated as the control group based on mean brachial-ankle pulse wave velocity value. Multivariate adjusted ORs (95% confidence intervals) for brachial-ankle pulse wave velocity across the uric acid quartiles were 2.642 (Q1, 1.095–6.3373), 1.00, 4.305 (Q3, 1.798–10.307), and 4.375 (Q4, 1.923–9.949), after adjusting for confounding variables.

Conclusion

Serum uric acid level has a J-shaped association with arterial stiffness in Korean postmenopausal women.

Uric acid as one of the important factors in multifactorial disorders--facts and controversies

With considering serum concentration of the uric acid in humans we are observing hyperuricemia and possible gout development. Many epidemiological studies have shown the relationship between the uric acid and different disorders such are obesity, metabolic syndrome, hypertension and coronary artery disease. Clinicians and investigators recognized serum uric acid concentration as very important diagnostic and prognostic factor of many multifactorial disorders. This review presented few clinical conditions which are not directly related to uric acid, but the concentrations of uric acid might have a great impact in observing, monitoring, prognosis and therapy of such disorders. Uric acid is recognized as a marker of oxidative stress. Production of the uric acid includes enzyme xanthine oxidase which is involved in producing of radical-oxigen species (ROS). As by-products ROS have a significant role in the increased vascular oxidative stress and might be involved in atherogenesis. Uric acid may inhibit endothelial function by inhibition of nitric oxide-function under conditions of oxidative stress. Down regulation of nitric oxide and induction of endothelial dysfunction might also be involved in pathogenesis of hypertension. The most important and well evidenced is possible predictive role of uric acid in predicting short-term outcome (mortality) in acute myocardial infarction (AMI) patients and stroke. Nephrolithiasis of uric acid origin is significantly more common among patients with the metabolic syndrome and obesity. On contrary to this, uric acid also acts is an “antioxidant”, a free radical scavenger and a chelator of transitional metal ions which are converted to poorly reactive forms.

[Hyperuricemia and uro-nephrological disorders]

Hyperuricemia is a specific risk factor for cardiovascular morbidity and mortality. Uric acid lithiasis is urological symptom of hyperuricemia. In case of uric acid lithiasis, you must search a metabolic syndrome, an insulin resistance, a type 2 diabetes. Chronic tubular interstitial nephropathy is the renal disease of hyperuricemia. Hyperuricemia is a specific risk factor for chronic renal failure. Metabolism of uric acid involves the uromodulin.

The relationship between normal serum uric acid and nonalcoholic fatty liver disease

The objective of the present study was to determine the relationship between serum uric acid (SUA) level and the presence of nonalcoholic fatty liver disease (NAFLD). We analyzed data of 9,019 Koreans who visited a health check up center. The SUA levels of all of these subjects were within the normal range. The participants were divided into 4 groups according to the quartiles of the SUA levels for both sexes. Hepatic steatosis was diagnosed on the basis of ultrasonographic findings. Multivariate logistic regression modeling was performed across the SUA quartiles. The presence of NAFLD and metabolic abnormalities were found significantly in subjects with high-normal SUA levels. After adjustment for age, metabolic components, and the liver-function test, the adjusted odds ratio (OR, 95% CIs) for the presence of NAFLD in the subjects with the highest SUA level was 1.46 (1.17-1.82) for men and 2.13 (1.42-3.18) for women, as compared to the subjects with the lowest SUA level. Our results suggest that increased SUA concentrations, even within the normal range, are independently associated with the presence of NAFLD.