The effect of baseline serum uric acid on chronic kidney disease in normotensive, normoglycemic, and non-obese individuals: A health checkup cohort study

Trend analysis and prediction of the incidence and mortality of CKD in China and the US

BACKGROUND

Currently, limited research is available on the comparative analysis of chronic kidney disease (CKD) incidence and mortality rates between China and the United States. This study aimed to explore the trends in CKD incidence and mortality rates in both countries, as well as make some future predictions.

METHODS

The data on CKD incidence and mortality in China and the US from 1990 to 2019 were derived from the 2019 Global Burden of Disease database. A Joinpoint regression model was used to analyze temporal trends in CKD incidence and mortality. An age-period-cohort model was used to assess the effects of age, period, and birth cohort on CKD risk and forecast the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of CKD in China and the US over the next 15 years.

RESULTS

CKD incidence in China and the US showed an upward trend. Its mortality rate showed a downward trend in China but an upward one in the US. The relative risk (RR) of CKD incidence and mortality increases with age. The RR of CKD incidence in the 0-5 age group exceeds that in the 5-55 age group, and the RR for mortality surpasses that in the 5-35 age group. Over time, the RR of CKD incidence has gradually increased in China and the US. Individuals born in later birth cohorts had a lower RR of CKD incidence and mortality. The ASIR of CKD may increase in both China and the US, whereas its ASMR may decline over the next 15 years.

CONCLUSION

Screening measures should be strengthened among populations at high risk of CKD; prenatal examinations of pregnant women should be emphasized to reduce CKD incidence in newborns. It is imperative to increase health education and encourage individuals to adopt healthy lifestyles.

Serum Uric Acid Levels and Their Association with Renal Function Decline and Kidney Disease Progression in Middle-Aged and Elderly Populations: A Retrospective Cohort Study

Objective

To evaluate the associations between serum uric acid (SUA) levels and estimated glomerular filtration rate (eGFR) and chronic kidney disease (CKD), with a focus on gender differences, and variations among women pre-and post-menopausal stages.

Design

A retrospective cohort study.

Setting

A large community-based survey was conducted every two years from 2010 to 2018 in Hangzhou, Zhejiang Province, Southeastern China.

Participants

10,218 participants (40 years or above) without CKD at baseline who underwent three physical examinations were enrolled. CKD was defined as an eGFR of less than 60 mL/min/1.73m2.

Methods

Participants with SUA levels were divided into four groups (Q1-Q4) based on baseline SUA quartiles. The Q1 was the reference. By stratifying participants by gender, the relationships between SUA levels and eGFR were investigated using the generalized additive mixture model. The associations of SUA and the risk of incident CKD were examined using multivariate logistic regression models in the generalized estimating equation.

Results

After adjusting for confounding variables, a nonlinear association between SUA and eGFR was observed in females, while an approximately linear relationship was observed in males, suggesting that elevated SUA levels are associated with renal function decline. Furthermore, the highest quartile of SUA was associated with a 2.16-fold (95% CI: 1.31-3.58) increased risk of CKD in males and a 2.76-fold (95% CI: 1.59-4.78) increased risk in females, compared with the lowest quartile. And the spline curves demonstrated a U-shaped pattern, suggesting a potential threshold effect of SUA on the risk of CKD. Additionally, Subgroup analyses revealed significant associations between elevated SUA levels with CKD in postmenopausal women, but not in premenopausal women.

Conclusion

Elevated SUA levels are associated with an increased risk of CKD development and renal function decline in middle-aged and elderly individuals, particularly in postmenopausal women.

Associations of serum uric acid with cardiovascular disease risk factors: a retrospective cohort study in southeastern China

OBJECTIVE

To evaluate the associations between serum uric acid (SUA) levels and cardiovascular disease (CVD) risk factors, focusing on potential sex-specific differences.

DESIGN

A retrospective cohort study.

SETTING

A large community-based survey was conducted every two years from 2010 to 2018 in Hangzhou, Zhejiang Province, outheastern China.

PARTICIPANTS

6119 participants aged 40 years and above who underwent at least three times of physical examinations were enrolled.

METHODS

Participants were categorised into four groups (Q1-Q4) based on baseline SUA quartiles within the normal range, with hyperuricaemia (HUA) as the fifth group. The Q1 was the reference. By stratifying participants by gender, the relationships between SUA levels and systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting blood glucose (FBG) and total cholesterol (TC) were investigated using linear regression models in the generalised estimating equation. Additionally, the associations of elevated SUA levels and HUA with hypertension, hyperglycaemia and dyslipidaemia were correspondingly examined using multivariate logistic regression models.

RESULTS

After adjusting for confounding variables, we found positive associations between SUA levels and SBP, DBP, FBG and TC in women, and with TC in men (p<0.01). Likewise, elevated SUA quartiles and HUA were linked to increased dyslipidaemia risk in both sexes, and increased hyperglycaemia risk only in women, with HRs (95% CI) of 1.64 (1.05 to 2.55) and 2.37 (1.47 to 3.81) in the Q4 and HUA group, respectively. Women with HUA had higher hypertension risk (HR=1.45, 95% CI 1.21 to 1.73), while no such association was observed in men. Stratified analyses revealed significant associations between elevated SUA levels and CVD risk factors in postmenopausal and non-obese women.

CONCLUSIONS

Elevated SUA levels increase the risk of dyslipidaemia in both sexes. SUA levels within normal range and HUA are positively associated with hyperglycaemia and hypertension in postmenopausal women, but not in men.

Metabolic Dysfunction-Associated Fatty Liver Disease in Newly Diagnosed, Treatment-Naive Hypertensive Patients and Its Association with Cardiorenal Risk Markers

INTRODUCTION

Patients with arterial hypertension frequently present with comorbidities that are associated with increased cardiorenal risk, such as metabolic dysfunction-associated fatty liver disease (MAFLD).

AIMS

Our study aimed to assess the prevalence and the association of MAFLD with cardiorenal risk markers in newly diagnosed, treatment-naïve hypertensive patients.

METHODS

We recruited 281 individuals with new-onset hypertension who were not prescribed any medication. Medical history, clinical examination findings, and laboratory test results were recorded. Liver steatosis was assessed through fatty liver index (FLI) calculation. Patients with FLI ≥ 60 together with one main metabolic abnormality (type 2 diabetes mellitus or overweight/obesity) or at least two metabolic risk abnormalities (increased waist circumference, blood pressure, plasma triglycerides, presence of prediabetes or insulin resistance, decreased plasma high-density lipoprotein) fulfilled the diagnostic criteria for MAFLD.

RESULTS

The prevalence of MAFLD in our study population was 28.7%. Individuals with MAFLD were more frequently male and had increased body mass index. Systolic, diastolic, and pulse pressure values were significantly higher in this group of patients. Moreover, lipid, renal, glucose, and inflammatory markers were considerably deranged in patients with MAFLD. After multivariate regression analysis, uric acid, ferritin, and apoE emerged as independent predictors of MAFLD. Area under receiver operating characteristics curve revealed that uric acid had the greatest diagnostic accuracy, with the ideal cutoff being ≥ 5.2 mg/dl (sensitivity: 77.6%, specificity: 76.3%).

CONCLUSION

MAFLD represents a common comorbidity in hypertensive patients and is associated with markers of cardiorenal risk. Uric acid may be indicative of MAFLD in particular.

Genetic Risk Score for Plasma Uric Acid Levels Is Associated With Early Rapid Kidney Function Decline in Type 2 Diabetes

CONTEXT

Observational studies have shown that elevated uric acid (UA) is associated with chronic kidney disease (CKD). However, whether the relationship is causal remains unclear.

OBJECTIVE

To determine the association of plasma UA and incident CKD and the causal relationship between plasma UA and rapid decline in kidney function (RDKF) in patients with type 2 diabetes (T2D).

METHODS

Multivariable Cox regression was conducted to evaluate the hazard ratio (HR) between plasma UA and incident CKD among 1300 normoalbuminuric patients in 2 T2D study cohorts (DN, n = 402; SMART2D, n = 898). A weighted genetic risk score (wGRS) was calculated based on 10 single nucleotide polymorphism (SNPs) identified in genome-wide association studies of UA in East Asians. Mendelian randomization (MR) analysis was performed among 1146 Chinese T2D patients without CKD (estimated glomerular filtration rate [eGFR] > 60 mL/min/1.73m2) at baseline (DN, 478; SMART2D, 668). The wGRS and individual SNPs were used as genetic instruments and RDKF was defined as eGFR decline of 5 mL/min/1.73m2/year or greater.

RESULTS

During mean follow-up of 5.2 and 5.4 years, 81 (9%) and 46 (11%) participants in SMART2D and DN developed CKD, respectively. A 1-SD increment in plasma UA conferred higher risk of incident CKD (DN, adjusted-HR = 1.40 [95% CI, 1.02-1.91], P = 0.036; SMART2D, adjusted-HR = 1.31 [95% CI, 1.04-1.64], P = 0.018). Higher wGRS was associated with increased odds for RDKF (meta-adjusted odds ratio = 1.12 [95% CI, 1.01-1.24], P = 0.030, Phet = 0.606).

CONCLUSION

Elevated plasma UA is an independent risk factor for incident CKD. Furthermore, plasma UA potentially has a causal role in early eGFR loss in T2D patients.

Serum Uric Acid Levels and Cardiometabolic Profile in Middle-Aged, Treatment-Naïve Hypertensive Patients

INTRODUCTION

Uric acid (UA) is a risk factor associated with cardiometabolic diseases. However, the appropriate threshold of UA remains a matter of controversy.

AIM

To assess whether slightly increased UA levels have any significance in middle-aged, treatment-naïve persons with new-onset hypertension.

METHODS

In this cross-sectional study we recruited middle-aged participants with new-onset hypertension who were treatment-naïve. Subjects below (Group 1) and above the median UA levels (Group 2) were compared regarding clinical and laboratory characteristics that are implicated in cardiovascular and renal risk. The study population consisted of 369 persons (mean age 48.4±10 years) with median UA of 4.8 mg/dl. Group 2 individuals were predominantly male and had higher levels of blood pressure, increased body mass index, waist circumference, and a greater degree of insulin resistance. Additionally, greater lipid profile abnormalities were detected. This group also exhibited a significantly decreased fractional excretion of UA. Multivariate analysis demonstrated that serum UA levels were correlated with male sex, waist circumference, estimated glomerular filtration rate (eGFR), serum calcium and insulin levels, as well as with fractional excretion of UA. A positive association between serum UA levels and the number diagnostic criteria of the metabolic syndrome (MtS) was also noticed. After reclassification of subjects according to UA quartiles, individuals with UA levels ≥ 3.8 mg/dl had significantly higher odds (2.5-fold to 9.8-fold) of having MtS after adjustment of age, sex, and eGFR.

CONCLUSIONS

Uric acid levels in middle-aged, treatment-naïve hypertensive patients are correlated with risk factors for cardiovascular and renal disease.

A systematic review and meta-analysis of the association between uric acid levels and chronic kidney disease

The function of uric acid (UA) in the genesis and evolution of chronic kidney disease (CKD) has motivated numerous studies, but the results remain inconclusive. We sought to conduct a systematic review and meta-analysis of cohort studies aiming to analyze the association of UA levels with the incidence and progression of CKD. Pubmed/Medline, Lilacs/Bireme and Web of Science were searched to identify eligible studies, following the PRISMA protocol. Data were presented for CKD incidence and progression separately. For the meta-analysis, studies with data stratified by subgroups according to serum UA levels were selected. The inverse variance-weighted random effects model was used to generate a combined effect estimate. Meta-regressions were performed to identify the causes of heterogeneity. The Newcastle-Ottawa Scale was used to assess the risk of bias. The publication bias was tested by funnel plot and Egger's test. Eighteen CKD incidence studies (n = 398,663) and six CKD progression studies (n = 13,575) were included. An inverse relationship was observed between UA levels and protection from CKD incidence and progression. Lower UA levels were protective for the risk of CKD incidence (RR 0.65 [95% CI 0.56-0.75]) and progression (RR 0.55 [95% CI 0.44-0.68]). UA seems to be implicated both in the genesis of CKD and its evolution.

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.