Evaluation of the Chronic Kidney Disease Epidemiology Collaboration equation for estimating the glomerular filtration rate in multiple ethnicities

Nocturnal Systolic Hypertension and Adverse Prognosis in Patients with CKD

BACKGROUND AND OBJECTIVES

Nocturnal hypertension is associated with adverse outcomes in patients with CKD. However, the individual association of entities of nocturnal hypertension according to achievement of systolic and/or diastolic BP goals with kidney failure and cardiovascular outcomes of CKD is not clear.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study analyzed data from participants in the Chinese Cohort Study of Chronic Kidney Disease. Nocturnal hypertension was categorized into three entities: isolated nocturnal diastolic hypertension with diastolic BP ≥70 mm Hg and systolic BP <120 mm Hg, isolated nocturnal systolic hypertension with systolic BP ≥120 mm Hg and diastolic BP <70 mm Hg, and nocturnal systolic-diastolic hypertension with both systolic BP ≥120 mm Hg and diastolic BP ≥70 mm Hg. Associations of nocturnal hypertension entities with kidney failure and cardiovascular outcomes were evaluated by Cox regression.

RESULTS

In total, 2024 patients with CKD stages 1-4 were included in our analysis (mean age, 49±14 years; 57% men; eGFR=51±29 ml/min per 1.73 m²; proteinuria: 0.9 [0.4-2.1] g/d). Among them, 1484 (73%) patients had nocturnal hypertension, with the proportions of 26%, 8%, and 66% for isolated nocturnal diastolic hypertension, isolated nocturnal systolic hypertension, and nocturnal systolic-diastolic hypertension, respectively. Three hundred twenty kidney events and 148 cardiovascular events were recorded during median follow-up intervals of 4.8 and 5.0 years for kidney and cardiovascular events, respectively. After adjustment, isolated nocturnal systolic hypertension was associated with a higher risk for cardiovascular events (hazard ratio, 3.17; 95% confidence interval, 1.61 to 6.23). Nocturnal systolic-diastolic hypertension showed a higher risk for both kidney failure (hazard ratio, 1.71; 95% confidence interval, 1.17 to 2.49) and cardiovascular outcomes (hazard ratio, 2.19; 95% confidence interval, 1.24 to 3.86). No association was observed between isolated nocturnal diastolic hypertension with either kidney failure or cardiovascular events.

CONCLUSIONS

Nocturnal systolic hypertension, either alone or in combination with diastolic hypertension, is associated with higher risks for adverse outcomes in patients with CKD.

Antimicrobial Dosing in Specific Populations and Novel Clinical Methodologies: Kidney Function

Kidney function is a common parameter used to define antimicrobial drug dosage and frequency of administration. Several methods exist to measure kidney function but for pragmatic reasons rely on estimated kidney function equations based on the endogenous biomarker serum creatinine and common clinical variables. Current regulatory guidance on the design of studies in patients with abnormal kidney function in the United States also recommend consideration of estimated kidney function for this reason. Over the past few decades, alternate endogenous biomarkers, administration of exogenous biomarkers for noninvasive measurement, use of probe substrates to characterize individual kidney drug clearance pathways, modifications to conventional equations to account for time-varying clearance, and improved clinical trial modeling and simulation to factor in these uncertainties have occurred. Furthermore, major changes to kidney replacement therapy delivery in the outpatient, inpatient, and at-home setting are occurring. Antimicrobial drug dose adjustment in this diverse population is complex and in a state of flux due to technical innovations. Over-reliance on kidney function estimates to guide drug dosing in patients with infectious diseases can bias underdosing especially among the acutely ill. A holistic approach to drug dose adjustment in patients with abnormal kidney function is necessary to optimize clinical outcomes.

Estimated glomerular filtration rate in children: adapting existing equations for a specific population

BACKGROUND

Creatinine-based glomerular filtration rate (GFR)-estimating equations frequently do not perform well in populations that differ from the development populations in terms of mean GFR, age, pathology, ethnicity, and diet. After first evaluating the performance of existing equations, the aim of this study was to demonstrate the utility of an in-house modification of the equations to better fit a specific population.

METHODS

Estimated GFR using 8 creatinine-based equations was first compared to 2-sample ⁵¹Cr-ethylenediaminetetra-acetic acid plasma clearance in non-cancer and cancer groups independently. The groups were then divided into development and validation sets. Using the development set data, the Microsoft® Excel SOLVER add-in was used to modify the parameters of 7 equations to better fit the data. Using the validation set data, the performance of the original and modified equations was compared.

RESULTS

Two hundred fifty-six GFR measurements were performed in 160 children. GFR was overestimated in both groups (non-cancer 4.3-22.6 ml/min/1.73 m², cancer 17.2-46.6 ml/min/1.73 m²). The root mean square error (RMSE) was 19.1-21.8 ml/min/1.73 m² (non-cancer) and 18.6-20.8 ml/min/1.73 m² (cancer). The P₃₀ values were 49.1-73.0% (non-cancer) and 19.6-66.0% (cancer). Modifying the parameters of seven equations resulted in significant improvements in the P₃₀ values in the non-cancer (65.0-85.0%) and cancer (79.6-87.8%) groups.

CONCLUSIONS

Modifying the parameters of pediatric GFR estimating-equations using a simple Excel-based tool significantly improved their accuracy in both non-cancer and cancer populations. Graphical abstract.

Effect of Brachial-Ankle Pulse Wave Velocity Combined with Waist-to-Hip Ratio on Cardiac and Cerebrovascular Events

BACKGROUND

Abdominal obesity and brachial-ankle pulse wave velocity (baPWV) are indicators of atherosclerosis. But few studies have shown the relationship between baPWV combined with waist-hip ratio (WHR) and cardiac-cerebrovascular events (CCVEs).

METHODS

A total of 18944 subjects from Kailuan study were enrolled in this study. Follow-up was conducted three times over 4.82±1.92 years. All the participants were divided into 4 groups according to baPWV and WHR status on baseline: Q1 (normal baPWV, normal WHR), Q2 (normal baPWV, increased WHR), Q3 (increased baPWV, normal WHR) and Q4 (increased baPWV, increased WHR). The incidence and risk factors and further analysis of hypertension subgroups were analyzed.

RESULTS

During follow-up, 88 myocardial infarctions (MI), 278 cerebral ischemic strokes (CI), 285 strokes and 371 CCVEs occurred, with the cumulative incidence of 0.46%, 1.47%, 1.50%, and 1.96%, respectively. Multivariate Cox regression analysis revealed the risk of CI, stroke and CCVEs was higher in patients with increased baPWV and increased WHR than in the other three groups, followed by the Q3 group (increased baPWV, normal WHR) and Q2 group (normal baPWV, increased WHR) group (all adjusted P<0.01). Further hypertension subgroups analysis showed similar results, but differences were more significant among hypertensive patients. Accordingly, the combination of baPWV and WHR increased the risk of total CCVEs, especially in hypertensive patients.

CONCLUSIONS

BaPWV and WHR were important risk factors for CCVEs and had synergistic effects. When baPWV increased, WHR may contribute more to the risk of CCVEs in hypertensive patients.

Triglycerides to high-density lipoprotein cholesterol ratio is superior to triglycerides and other lipid ratios as an indicator of increased urinary albumin-to-creatinine ratio in the general population of China: a cross-sectional study

Background

Dyslipidemia contributes to the pathogenesis of renal dysfunction. Previous research demonstrated that triglycerides (TG), instead of other individual lipid indexes, has a significant link with elevated urinary albumin-to-creatinine ratio (UACR). However, it is unclear whether lipid ratios are superior indicators of increased UACR compared with TG. This research is to determine whether there are close relationships of lipid ratios with UACR in a general population.

Methods

35,751 participants from seven centers across China were enrolled. UACR equal or higher than 30 mg/g was recognized as increased albuminuria. The associations of TG, low-density lipoprotein cholesterol (LDL-C)/ high-density lipoprotein cholesterol (HDL-C), TG/HDL-C and non-high-density lipoprotein cholesterol (non-HDL-C)/HDL-C with increased UACR were evaluated by linear and logistic regression analyses in females and males separately.

Results

There were 3692 (14.8%) female subjects, and 1307 (12.0%) male subjects characterized as having increased UACR. There were significantly differences in TG/HDL-C and non-HDL-C/HDL-C between the normal UACR group and the increased UACR group, while LDL-C/HDL-C was not. Furthermore, linear regression analysis was implemented and showed that TG and TG/HDL-C were both positively related to UACR even after a variety of potential confounders were adjusted regardless of sexes, while the correlation between non-HDL-C/HDL-C and elevated UACR were only significant in females. Further analyses utilizing logistic regression demonstrated that compared with non-HDL-C/HDL-C and TG, TG/HDL-C showed the strongest association with increased UACR (quartile 1 of TG/HDL-C as a reference; OR [95% CI] of quartile 4: 1.28 [1.13–1.44] in women, 1.24 [1.02–1.50] in men) after fully adjusting for potential confounding factors. Stratified analyses revealed that in males who were overweight and in females who were overweight or over 55 years or had prediabetes or prehypertension, TG/HDL-C had significant associations with abnormal UACR.

Conclusions

Compared with TG and other routine lipid ratios, TG/HDL-C is a superior indicator for increased UACR.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12944-021-01442-8.

Association between hypertension-mediated organ damage and obesity defined by novel anthropometric indices in community-dwelling elderly individuals

OBJECTIVE

Body mass index (BMI), the most common anthropometric index, has recently been challenged by two emerging parameters: a body shape index (ABSI) and body roundness index (BRI). The purpose of this study was to explore the associations of hypertension-mediated organ damage (HMOD) with conventional and novel anthropometric parameters.

METHODS

This is a multistage community-based observational and cross-sectional study. A total of 3077 elderly Chinese individuals (mean age 70.92 ± 5.84, 1329 (43%) men) from the communities in the northern area of Shanghai were enrolled from June 2014 to August 2019. Waist-to-hip ratio (WHR), ABSI and BRI were calculated with validated formulas. HMOD, including left ventricular hypertrophy (LVH), arterial stiffness (AS), lower limb atherosclerosis (LLA), and microalbuminuria (MAU), was assessed using standardized methods. Correlation and multivariable linear and logistic regression analyses were performed to detect the relations between HMOD and anthropometric indices.

RESULTS

In the total population, compared to those with ABSI, BRI and WHR in the lowest quartiles, participants with values in the highest quartiles exhibited a significantly higher risk of LVH, AS and MAU independent of BMI and other confounders (all P for trend <0.01). In females but not in males, compared to BMI, BRI and WHR had a greater area under the curve (AUC) for detecting HMOD. In the further stepwise logistic regression with all anthropometric indices put into models simultaneously, only BRI remained in the LVH (odds ratio [OR]: 1.42, 95% confidence interval [CI]: 1.30-1.55) and LLA (OR: 1.48, 95% CI: 1.23-1.77) models, and WHR remained in the AS (OR: 1.30, 95% CI: 1.18-1.43) and MAU (OR: 1.48, 95% CI: 1.28-1.72, all P < 0.01) models.

CONCLUSION

Compared to BMI, the novel anthropometric parameter BRI, together with the conventional parameter WHR, exhibits a closer relationship with HMOD in the elderly population, especially in females.

A Review of Specific Biomarkers of Chronic Renal Injury and Their Potential Application in Nonclinical Safety Assessment Studies

A host of novel renal biomarkers have been developed over the past few decades which have enhanced monitoring of renal disease and drug-induced kidney injury in both preclinical studies and in humans. Since chronic kidney disease (CKD) and acute kidney injury (AKI) share similar underlying mechanisms and the tubulointerstitial compartment has a functional role in the progression of CKD, urinary biomarkers of AKI may provide predictive information in chronic renal disease. Numerous studies have explored whether the recent AKI biomarkers could improve upon the standard clinical biomarkers, estimated glomerular filtration rate (eGFR), and urinary albumin to creatinine ratio, for predicting outcomes in CKD patients. This review is an introduction to alternative assays that can be utilized in chronic (>3 months duration) nonclinical safety studies to provide information on renal dysfunction and to demonstrate specific situations where these assays could be utilized in nonclinical drug development. Novel biomarkers such as symmetrical dimethyl arginine, dickkopf homolog 3, and cystatin C predict chronic renal injury in animals, act as surrogates for GFR, and may predict changes in GFR in patients over time, ultimately providing a bridge from preclinical to clinical renal monitoring.

Predictive Value of Creatinine-based Equations of Kidney Function in the Long-term Prognosis in United Arab Emirates Patients

Objectives

Chronic kidney disease (CKD) is an independent predictor of mortality. Several creatinine-based equations are used to assess the estimated glomerular filtration rate or creatinine clearance and mortality prediction in various ethnic populations. Similarly, renal insufficiency is associated with poor prognosis of UAE nationals with cardiovascular disease (CVD) risk factors. However, the equation that best assesses prognosis among these patients is unknown. This study aimed to compare the prognostic abilities of different creatinine-based kidney function equations for predicting all-cause mortality in UAE nationals with vascular comorbidities.

Methods

This retrospective observational study analyzed 1186 patients (54.0% men) with CVD risk factors. Multivariable Cox regression analysis was used to evaluate the associations of categorical renal function stages with all-cause mortality. Measures of performance in each equation assessed with respect to all-cause mortality were evaluated and compared to the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation by calculating the C-index, net reclassification index (NRI), and integrated discrimination index.

Results

Over a median follow-up of 8.9 years, the cumulative incidence of all-cause mortality was 9.4% (n = 112). After multivariable adjustment, the discriminative ability for all-cause mortality was significantly higher in the body surface area-adjusted Cockcroft-Gault (BSA-CG) formula than in the CKD-EPI equation (C-indices: 0.869 vs. 0.861, respectively, p = 0.037). NRI was significantly positive and favored the BSA-CG formula (0.54; 95% confidence interval: 0.35–0.64) compared to the CKD-EPI equation.

Conclusions

Our findings suggest that the BSA-CG equation may have the potential to slightly improve mortality prediction compared to the CKD-EPI equation in UAE nationals with vascular risk. Further large multicenter studies are warranted to confirm our findings.

Association between airborne particulate matter and renal function: An analysis of 2.5 million young adults

BACKGROUND

Limited studies have examined the impact of airborne particulate matter of 2.5 μm or less (PM_2.5) on renal function. No study has examined the effect of PM₁, which is small enough to reach the blood circulation. We examined whether exposure to PM₁ or PM_2.5 affected renal function of young Han Chinese.

METHOD

We included 2,546,047 young adults who were aged 18 to 45 years, being Han ethnicity and had no chronic disease from a Chinese national birth cohort. Serum creatinine (Scr) of each participant was measured during the baseline examination. Estimated glomerular filtration rate (eGFR) were calculated for each participant using the latest Chronic Kidney Disease Epidemiology Collaboration equation. One-year average exposure to PM₁ and PM_2.5 prior to the health examination for each participant were estimated using machine learning models with satellite remote sensing information. Generalized additive mixed models were used to estimate associations between PM₁ or PM_2.5 and renal function after adjusting for detailed individual variables.

RESULTS

A 10 μg/m³ increment in PM₁ exposure was associated with -0.95% (95%CI: -1.04%, -0.87%) difference of eGFR in females and -0.37% (95%CI: -0.44%, -0.31%) in males. For PM_2.5, the corresponding difference of eGFR was -0.99% (95%CI: -1.05%, -0.93%) in females and -0.48% (95%CI: -0.53%, -0.43%) in males, respectively. Associations between eGFR and PM were higher in females compared to males (p < 0.05 for interaction test). Association with PM₁ were weaker than that with other fractions included in PM_2.5. Participants who worked as farmers, were of normal weight, were not exposed to tobacco smoking, did not drink alcohol, had higher associations between eGFR and PM than their counterparts (p < 0.05 for interaction test).

CONCLUSION

Exposure to PM₁ and PM_2.5 was associated with reduced renal function among Han Chinese at reproductive age.

Correlation of Indoleamine-2,3-Dioxygenase and Chronic Kidney Disease: A Pilot Study

Objective

To explore the correlation of indoleamine-2,3-dioxygenase (IDO) and chronic kidney disease (CKD).

Methods

A total of 154 CKD patients and 42 non-CKD patients were recruited. Patients were grouped into ACR1~ACR3 (<30 mg/g, 30-300 mg/g, and >300 mg/g). Biomarkers in different groups were compared by ANOVA. Correlation was calculated by Pearson or Spearman analysis and binary logistic regression. The ROC curve was also performed.

Results

The levels of albumin, serum creatinine (sCr), and IDO in non-CKD patients were significantly different from those in CKD3-CKD5 stages (p < 0.05). IDO was correlated with age, proteinuria, ACR, and eGFR (p < 0.01). After adjusting for CKD-related indices, ln(IDO) was an independent risk factor for CKD (3.48, p < 0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.0466 and yielded a sensitivity of 83.8% and a specificity of 75%. Hemoglobin, total protein, and albumin in the ACR1 group were significantly higher than those in the ACR2 and ACR3 groups (p < 0.01), while sCr and IDO levels were significantly lower than those in the ACR2 and ACR3 groups (p < 0.01 or p < 0.05). After adjusting for CKD-related indices, ln(IDO) was still an independent risk factor for ACR (OR = 2.7, p < 0.05). The analysis of ROC curve revealed a best cut­off for IDO was 0.075 and yielded a sensitivity of 71.9% and a specificity of 72.2%.

Conclusion

IDO may be a promising biomarker to predict CKD and assess kidney function.

Comparative performance of FAS equation and Asian modified CKD-EPI in the determination of GFR in Chinese patients with CKD with the 99mTc-DTPA plasma clearance as the reference method

BACKGROUND

Glomerular filtration rate (GFR) is a useful index in many clinical conditions. However, very few studies have assessed the performance of full age spectrum (FAS) equation and the Asian modified Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation in the approximation of GFR in Chinese patients with chronic kidney disease.

OBJECTIVE

This study aimed to compare the diagnostic performance of the above two creatinine-based equations.

METHODS

A well designed single-center cross-sectional study was performed and the GFR was determined by 3 methods separately in the same day: technetium-99m-diethylene triamine pentaacetic acid (^99mTc-DTPA) dual plasma sample clearance method (mGFR); FAS equation method; Asian modified CKD-EPI equation method. The gold standard method was the mGFR. Equations performance criteria considered correlation coefficient, bias, precision, accuracy and the ability to detect the mGFR less than 60ml/min/1.73m².

RESULTS

A total of 160 patients were enrolled. The diagnostic performance of FAS showed no significant difference in the correlation coefficient (0.89 vs 0.89), precision (15.9 vs 16.1ml/min/1.73m²), accuracy (75.0% vs 76.3%) and the ability to detect the mGFR less than 60ml/min/1.73m² (0.94 vs 0.94) compared with the Asian modified CKD-EPI equation in all participants. The FAS showed a negative bias, while the new CKD-EPI equation showed a positive bias (-1.20 vs 1.30ml/min/1.73m², P<0.001). However, they were all near to zero. In the mGFR<60ml/min/1.73m² subgroup and mGFR>60ml/min/1.73m² subgroup were consistent with that in the whole cohort. The precision and accuracy decreased when GFR>60ml/min/1.73m² in both equations.

CONCLUSIONS

The FAS equation and the Asian modified CKD-EPI equation had similar performance in determining the glomerular filtration rate in the Chinese patients with chronic kidney disease. Both the FAS equation and Asian modified CKD-EPI can be a satisfactory method and may be the most suitable creatinine-based equation.

Association between Dietary Patterns and Kidney Function Parameters in Adults with Metabolic Syndrome: A Cross-Sectional Study

This study explored the association between dietary patterns and kidney function parameters in adults with metabolic syndrome in Taiwan. This cross-sectional study was undertaken in 56,476 adults from the health screening centers in Taiwan from 2001 to 2010. Dietary intake and dietary patterns were assessed using a food frequency questionnaire and principal component analysis, respectively. Blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR), and uric acid were measured as clinical parameters of kidney function. Multivariate linear regression was conducted to explore the relationship between dietary patterns and kidney function parameters. After adjusting for confounders, the highest tertiles of the processed food–sweets dietary pattern and the meat–seafood–eggs dietary pattern were associated with increased BUN, creatinine, and uric acid but decreased eGFR (all adjusted p < 0.05). Meanwhile, the highest tertiles of the veggie–fruit–grains dietary pattern and the milk–dairy dietary pattern were associated with decreased BUN, creatinine, and uric acid but increased eGFR (all adjusted p < 0.05). A processed food–sweets dietary pattern or a meat–seafood–eggs dietary pattern is associated with worse kidney function parameters in adults with metabolic syndrome. In contrast, a veggie–fruit–grains dietary pattern or a milk–dairy dietary pattern is associated with better kidney function parameters.

Fetal exposure to the Great Chinese Famine and risk of ischemic stroke in midlife

BACKGROUND AND PURPOSE

Epidemiological studies have reported an association between famine exposure and increased risk of cardiovascular disease. However, it is unclear whether fetal exposure to the Great Chinese Famine of 1959 to 1961 was associated with risk of ischemic stroke in midlife.

METHODS

A total of 17,787 participants of the Kailuan study, who were free of cardiovascular disease and cancer at baseline (2006) were enrolled in the study. All participants were divided into three groups: unexposed (born between 1 October 1962 and 30 September 1964, used as the reference group in current analyses), fetal exposure (born between 1 October 1959 and 30 September 1961), and early childhood exposure (born between 1 October 1956 and 30 September 1958). Incident ischemic stroke cases between 2006 and 2017 were confirmed by review of medical records. Cox proportional hazards regression was applied to analyze the effect of fetal famine exposure on ischemic stroke risk.

RESULTS

During the mean (10.4 ± 2.2) years of follow-up, 547 incident ischemic stroke cases were identified. After adjustment for potential confounders, the hazard ratio (HR) for ischemic stroke was 1.45, and the 95% confidence interval (CI) was 1.14, 1.84 for fetal famine-exposed compared with unexposed individuals. Similar associations were observed in men (adjusted HR: 1.40; 95% CI: 1.08, 1.80) and overweight individuals (adjusted HR: 1.56; 95% CI: 1.18, 2.07), but not in their counterparts. The results of the early childhood-exposed group were similar to the above.

CONCLUSIONS

Our findings support an association between fetal malnutrition and higher risk of ischemic stroke in adulthood.

Does Serum Uric Acid Status Influence the Association Between Left Atrium Diameter and Atrial Fibrillation in Hypertension Patients?

Objective: Both serum uric acid (SUA) levels and left atrium diameter (LAD) associate with AF. However, the influence of SUA status for the associated risk of AF related to LAD in hypertension patients is currently unknown.

Methods: We retrospectively analyzed a hospital-based sample of 9,618 hypertension patients. Standard electrocardiograms were performed on all patients and were interpreted by expert electro-physiologists.

Results: Overall 1,028 (10.69%) patients had AF out of 9,618 patients. In men >65 years of age, the prevalence of AF in the1st, 2nd, and 3rd tertiles of SUA among those grouped in the third tertile of LAD were 9, 12.3, and 21.7%, respectively. In the hyperuricemia group, the OR (95% CI) of AF for the highest tertile of LAD in men ≤ 65 years of age was 3.150 (1.756, 5.651; P < 0.001). Similarly, the hyperuricemic men in the 3rd LAD tertile had a higher likelihood of AF than those belonging to the 1st tertile. The ORs and (95% CIs) were 3.150 (1.756, 5.651; P < 0.001) and 5.522 (2.932, 10.400; P ≤ 0.001) for patients ≤ 65 and >65 years of age. An increase in SUA values was significantly associated with an increased likelihood of AF among women at the top tertiles of LAD, with the OR (95% CI) = 4.593 (1.857, 11.358; P = 0.001). Also, men> 65 years of age with large LAD, present at the third tertile of SUA, had a higher likelihood of AF, with the OR (95% CI) = 2.427 (1.039, 5.667; P < 0.05).

Conclusion: SUA levels and LAD are associated with AF in patients with hypertension and the risk of AF associated with LAD increases among those with hyperuricemia.

Serum TNF-α Level Is Associated with Disease Severity in Adult Patients with Immunoglobulin A Vasculitis Nephritis

Background

Tumor necrosis factor-α (TNF-α) is a proinflammatory factor involved in the pathogenesis of immunoglobulin A vasculitis (IgAV). The association between serum TNF-α and disease severity in adult patients with IgAV nephritis (IgAV-N) has been inadequately evaluated.

Methods

Serum TNF-α was measured by chemiluminescence immunoassay in 53 renal biopsy-proved IgAV-N patients, 53 healthy controls, and 53 IgA nephropathy (IgAN) patients. The correlations of clinicopathologic parameters of IgAV-N patients with serum TNF-α were analyzed.

Results

In this cross-sectional study, the median age of IgAV-N patients was 29 (25-37) years, and 67.9% were female. Serum TNF-α was significantly higher in the IgAV-N group than in the healthy group [7.4 (5.7-9.4) pg/mL vs. 5.9 (5.0, 7.1) pg/mL, P = 0.001], but comparable with sex, age, and estimated glomerular filtration rate (eGFR) grade-matched IgAN patients. Serum creatinine (P = 0.006) and serum cystatin C (P = 0.001) were positively correlated with serum TNF-α level, while albumin (P = 0.014) and eGFR (P = 0.021) were negatively correlated with serum TNF-α level. Multivariate linear regression analysis revealed that eGFR (P = 0.007) was an independent clinical predictor of serum TNF-α. Patients with higher pathological classification grade also had higher serum TNF-α.

Conclusions

Serum TNF-α is associated with renal function and the pathological classification of adult patients with IgAV-N. TNF-α is a potential biomarker for the assessment of IgAV-N severity.

On the Basis of Race: The Utility of a Race Factor in Estimating Glomerular Filtration

BACKGROUND

Glomerular filtration rate (GFR) is a measure of the combined rate of filtration of all functional nephrons in the kidney. Measurement of GFR is used in the clinic to detect, stratify, and monitor progression of kidney dysfunction, and also serves as a prognostic tool for staging chronic kidney disease (CKD). The gold standard method for measuring GFR is by plasma or urine clearance of exogenous filtration markers, but this is not feasible in routine clinical practice. The most commonly used method to assess GFR is using equations for estimated GFR (eGFR).

CONTENT

Addition of a race factor to eGFR equations has been recommended to optimize performance for Black individuals. Here, we review the basis of the race-based equation and assess its utility and widespread applicability.

SUMMARY

Although evidence supporting the performance of a race factor exists in the unique populations in which these estimation equations were derived, more studies are needed to assess the need, or lack thereof, for race factors for all ethnicities. Furthermore, ethnicity is complex and likely cannot be qualified with a 2-level descriptor.

Racialized algorithms for kidney function: Erasing social experience

The rise of evidence-based medicine, medical informatics, and genomics --- together with growing enthusiasm for machine learning and other types of algorithms to standardize medical decision-making --- has lent increasing credibility to biomedical knowledge as a guide to the practice of medicine. At the same time, concern over the lack of attention to the underlying assumptions and unintended health consequences of such practices, particularly the widespread use of race-based algorithms, from the simple to the complex, has caught the attention of both physicians and social scientists. Epistemological debates over the meaning of "the social" and "the scientific" are consequential in discussions of race and racism in medicine. In this paper, we examine the socio-scientific processes by which one algorithm that "corrects" for kidney function in African Americans became central to knowledge production about chronic kidney disease (CKD). Correction factors are now used extensively and routinely in clinical laboratories and medical practices throughout the US. Drawing on close textual analysis of the biomedical literature, we use the theoretical frameworks of science and technology studies to critically analyze the initial development of the race-based algorithm, its uptake, and its normalization. We argue that race correction of kidney function is a racialized biomedical practice that contributes to the consolidation of a long-established hierarchy of difference in medicine. Consequentially, correcting for race in the assessment of kidney function masks the complexity of the lived experience of societal neglect that damages health.

Association between Neck Circumference and the Risk of Decreased Estimated Glomerular Filtration Rate in the General Population of China: A Cross-Sectional Study

Background

The burden of chronic kidney disease is increasing substantially worldwide. Neck circumference (NC), an anthropometric index for upper-body adiposity, has been recognized as an indicator of cardiometabolic diseases. However, the association between NC and renal dysfunction has not been fully disclosed.

Objectives

The aim of this study was to investigate the association between NC and estimated glomerular filtration rate (eGFR) in the general population in China.

Methods

A total of 8805 participants (3322 men and 5483 women) were enrolled in this study. Logistic regression analysis was conducted to examine the association between NC and eGFR. The male and female subjects were divided into four groups according to the NC quartiles. The primary outcome was defined as an eGFR ≤ 90 mL/min/1.73 m².

Results

Logistic regression analysis revealed that in both sexes, higher NC was significantly associated with a higher risk of decreased eGFR even after fully adjusting for age, other anthropometric indexes, traditional risk factors for chronic kidney diseases, and sociologic risk factors (quartile 1 as a reference; the odds ratios [95% confidence intervals] were as follows: quartile 2, 1.26 [0.99-1.59]; quartile 3, 1.40 [1.07-1.83]; and quartile 4, 1.71 [1.22-2.38], in men; quartile 2, 1.14 [0.95-1.37]; quartile 3, 1.31 [1.03-1.66]; and quartile 4, 1.32 [1.04-1.68], in women). Stratified analyses suggested that the association was significant among subjects with prediabetes or normal serum uric acid levels and those without cardiovascular diseases (CVD). Among subjects with CVD, the association persisted only in males. When the subjects were stratified according to blood pressure or BMI, the association persisted among male subjects with abnormal blood pressure and was strengthened among male subjects who were overweight/obese, while the association disappeared among female subjects.

Conclusions

NC is independently associated with the risk of decreased eGFR in the general population in China, indicating that NC could contribute to renal dysfunction risk assessment.

Lead exposure and its association with cardiovascular disease and diabetic kidney disease in middle-aged and elderly diabetic patients

AIMS

Previous studies have suggested that a high blood lead level (BLL) is associated with cardiovascular outcomes and impaired renal function in the general population; however, studies investigating the effect of a high BLL on diabetic vascular complications have been limited. We aimed to investigate whether a higher BLL is associated with cardiovascular disease (CVD) and diabetic kidney disease (DKD).

METHODS

We analyzed 4234 individuals out of 4813 diabetic participants enrolled from seven communities in China in 2018 in this cross-sectional study. Macrovascular measurements, including assessment of common carotid artery (CCA) plaques and their diameters, were performed with ultrasound. CVD was defined as a composite measure including a previous diagnosis of coronary heart disease, myocardial infarction, or stroke. The definition of DKD was an albumin to creatinine ratio (ACR) ≥30 mg/g or an estimated glomerular filtration rate (eGFR) < 60 ml/min per 1.73 m². Linear and logistic regression analyses were used to measure the associations.

RESULTS

The median age and BLL of the participants were 67 years (interquartile range, 62-72 years) and 26 μg/L (interquartile range, 18-36 μg/L). Compared with the first quartile, the odds ratio (OR) (95% CI) of CCA plaques ranging from none to bilateral in the ordinal logistic regression analysis associated with BLL was 1.53 (1.29, 1.82) in the fourth BLL quartile (P for trend <0.01), and the odds of having CVD was significantly increased by 44% for participants in the fourth quartile (1.44 (1.17, 1.76)) (P for trend <0.01). The odds of DKD in the fourth BLL quartile increased by 36% (1.36 (1.06, 1.74)) compared with that in the first quartile (P for trend <0.05). These associations were adjusted for potential confounders.

CONCLUSIONS

A high BLL may be a potential risk factor for CVD and DKD in middle-aged and elderly diabetic adults.

Comparative performance of FAS equation and Asian modified CKD-EPI in the determination of GFR in Chinese patients with CKD with the 99mTc-DTPA plasma clearance as the reference method

BACKGROUND

Glomerular filtration rate (GFR) is a useful index in many clinical conditions. However, very few studies have assessed the performance of full age spectrum (FAS) equation and the Asian modified Chronic Kidney Disease-Epidemiology Collaboration (CKD-EPI) equation in the approximation of GFR in Chinese patients with chronic kidney disease.

OBJECTIVE

This study aimed to compare the diagnostic performance of the above two creatinine-based equations.

METHODS

A well designed single-center cross-sectional study was performed and the GFR was determined by 3 methods separately in the same day: technetium-99m-diethylene triamine pentaacetic acid (^99mTc-DTPA) dual plasma sample clearance method (mGFR); FAS equation method; Asian modified CKD-EPI equation method. The gold standard method was the mGFR. Equations performance criteria considered correlation coefficient, bias, precision, accuracy and the ability to detect the mGFR less than 60ml/min/1.73m².

RESULTS

A total of 160 patients were enrolled. The diagnostic performance of FAS showed no significant difference in the correlation coefficient (0.89 vs 0.89), precision (15.9 vs 16.1ml/min/1.73m²), accuracy (75.0% vs 76.3%) and the ability to detect the mGFR less than 60ml/min/1.73m² (0.94 vs 0.94) compared with the Asian modified CKD-EPI equation in all participants. The FAS showed a negative bias, while the new CKD-EPI equation showed a positive bias (-1.20 vs 1.30ml/min/1.73m², P<0.001). However, they were all near to zero. In the mGFR<60ml/min/1.73m² subgroup and mGFR>60ml/min/1.73m² subgroup were consistent with that in the whole cohort. The precision and accuracy decreased when GFR>60ml/min/1.73m² in both equations.

CONCLUSIONS

The FAS equation and the Asian modified CKD-EPI equation had similar performance in determining the glomerular filtration rate in the Chinese patients with chronic kidney disease. Both the FAS equation and Asian modified CKD-EPI can be a satisfactory method and may be the most suitable creatinine-based equation.

Economic Status Moderates the Association Between Early-Life Famine Exposure and Hyperuricemia in Adulthood

CONTEXT

The double burden of malnutrition (DBM), undernutrition in early life and an obesogenic environment later on, influences later risk of chronic disorders. The Great Famine in China from 1959 to1962 and remarkable economic development from the 1980s provided such a burden for a large number of people in their 60s.

OBJECTIVE

We aimed to analyze the effect of economic status on the association between famine exposure in early life and hyperuricemia in adulthood.

DESIGN AND SETTING

Participants numbering 12 666 were enrolled in China based on the Survey on Prevalence in East China for Metabolic Diseases and Risk Factors (SPECT-China) Study from 2014 to 2016.

PARTICIPANTS

Participants with fetal or childhood famine exposure (birth year 1949-1962) formed the exposure group.

MAIN OUTCOME MEASURE

Hyperuricemia was defined as uric acid (UA) > 420 μmol/L for men and > 360 μmol/L for women. The association of famine with hyperuricemia was assessed via regression analyses.

RESULTS

Early-life famine exposure was negatively associated with UA levels (P = .045) but was not associated with hyperuricemia (P = .226) in the whole study population. Economic status could moderate the association of famine exposure with UA and hyperuricemia (P ≤ .001). In participants with high economic status, early-life famine exposure was positively associated with UA levels (unstandardized coefficients 7.61, 95% CI 3.63-11.59, P < .001), and with hyperuricemia (odds ratio 1.47, 95% CI 1.19-1.81, P < .001).

CONCLUSIONS

Economic status could moderate the association between exposure to famine in early life and hyperuricemia in adulthood, indicating that the DBM might affect hyperuricemia in an opposite direction of the effects of undernutrition in early life alone.

Elevated circulating luteinizing hormone levels are associated with diabetic macroalbuminuria in Chinese men and postmenopausal women: A cross-sectional study

BACKGROUND

Associations between sex hormones and diabetic vascular complications have recently been studied, but the role luteinizing hormone (LH) plays in diabetic kidney disease (DKD) remains uncertain. We aimed to investigate the relationship of LH and DKD in Chinese men and postmenopausal women with type 2 diabetes mellitus (T2DM).

METHODS

Data were collected from 1775 T2DM men and postmenopausal women in hospital. The odds ratios (OR) and corresponding 95% confidence intervals (CI) in relation to LH quartiles were obtained by multiple logistic regression analysis.

RESULTS

LH levels were significantly higher in patients with macroalbuminuria than in those with microalbuminuria, but were not higher in patients with microalbuminuria than in those with normoalbuminuria. Consistently, LH in those with an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73m² were significantly higher than in those with eGFR≥60 mL/min/1.73m² . The prevalence of macroalbuminuria was obviously increased for subjects of the fourth quartile of LH vs the first to third quartile (20.4% vs 6.2%, 8.0%, 12.2% in men; 25.3% vs 5.5%, 3.8%, 9.3% in postmenopausal women). Multivariate logistic regression demonstrated that subjects within the highest quartile of LH had higher odds of macroalbuminuria than those within the lowest quartile (OR 4.00, 95% CI, 1.87-8.55 for men; OR 9.62, 95% CI, 3.42-27.08 for postmenopausal women), independent of age, diabetes duration, or other metabolic factors. The area under the curve for detecting macroalbuminuria based on LH was 0.662 for men, and 0.767 for postmenopausal women.

CONCLUSION

High LH levels are positively associated with established DKD among Chinese men and postmenopausal women. Elevated LH may be a promising clinical factor for identifying established DKD.

Associations of central and peripheral blood pressure with the renin-angiotensin-aldosterone system in healthy young adults: the African-PREDICT study

This study investigated associations of brachial and central blood pressure (BP) with detailed renin-angiotensin-aldosterone system (RAAS) components in a healthy young population stratified according to ethnicity and sex. We included healthy black men (n = 285) and women (n = 304) and white men (n = 278) and women (n = 305) aged 20-30 years old. We derived central systolic BP (cSBP), measured clinic and 24-h systolic and diastolic BP. Aldosterone and equilibrium angiotensin levels were assessed and used for calculating angiotensin-derived markers for plasma renin activity (PRA-S, Angiotensin I + Angiotensin II), angiotensin-converting enzyme (ACE-S, Angiotensin II/Angiotensin I), and two markers for adrenal effects of angiotensin II, the aldosterone-to-renin ratio (ARR-S, Aldosterone/PRA-S) and the aldosterone-to-angiotensin II-ratio (AA2-R, Aldosterone/Angiotensin II)_. Young black men and women presented with lower RAAS components and higher cSBP compared to their white counterparts (all p ≤ 0.001). In multivariable-adjusted regression analyses, positive associations of cSBP with ARR-S and AA2-R and negative associations with PRA-S and angiotensin II were found for black women (all p ≤ 0.001); this pattern was also observed for 24-h and clinic BP (p ≤ 0.045). A similar trend of RAAS associations was present in black men but only for clinic BP (all p ≤ 0.047). In white men, negative associations between clinic SBP and PRA-S, angiotensin II and aldosterone were detected (all p ≤ 0.048). No associations were observed in white women. Positive associations of central and peripheral BP with the ratio of aldosterone to PRA-S and angiotensin II only in healthy, young black adults suggest that relative aldosterone excess may contribute to early hypertension development in this group.

Urinary magnesium predicts risk of cardiovascular disease in Chronic Kidney Disease stage 1-4 patients

Observational studies on dietary or circulating magnesium and risk of cardiovascular disease (CVD) in Chronic Kidney Disease (CKD) stage 1-4 have reported no-to-modest inverse associations. 24 h Urinary magnesium concentration (24 h UMg), an indicator of intestinal magnesium absorption, may provide better insight into the connection of CKD progression. We examined 3179 participants aged 18-74 years with CKD stage 1-4 in the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE) study, a prospective population-based cohort study. Data were analysed using Spearman rank-order correlation coefficients for all comparisons. We also performed a time-to-event analysis of the data using the Kaplan-Meier survival model, Cox proportional hazard model and competing risk Fine and Gray subdistribution hazard model. During a median follow-up of 4.19 years (interquartile range, 3.43-5.09 years), when modelling end-stage renal disease (ESRD), CVD and death, 24 h UMg was associated with risk of CVD (HR, 1.612 (95% CI, 1.056-2.460)), while no significant association with ESRD and death endpoints could be detected. 24 h UMg risk variants display a modest association with CVD in CKD stage 1-4 patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03041987. Registered January 1, 2012. (retrospectively registered) (https://www.clinicaltrials.gov/ct2/show/NCT03041987?term=Chinese+Cohort+Study+of+Chronic+Kidney+Disease+%28C-STRIDE%29&rank=1).

Association of urine albumin-to-creatinine ratio with subclinical systolic dysfunction in hypertensive patients but not normotensive subjects: Danyang study

The association of albuminuria, as measured by urine albumin-to-creatinine ratio (UACR) concentration, with subclinical cardiac dysfunction in hypertensive patients is unclear. Our study aimed to examine its relationship in hypertensive patients compared with that in normotensive patients. The study participants were recruited from Danyang, a city of Jiangsu Province from 2017 to 2019. Categorical and continuous analyses were performed with sex-specific UACR tertiles and natural logarithmically transformed UACR, respectively. Comprehensive echocardiography including conventional imaging, tissue Doppler imaging, and 2D speckle tracking was performed using Philips CX50 device. The 2857 participants (mean age = 52.7 ± 11.8 years) included 1673 (58.6%) women, 1125 (39.4%) hypertensive patients, 546 (19.1%) patients with microalbuminuria, and 38 (1.3%) patients with macroalbuminuria. Comorbidities were increasingly prevalent across the tertiles of UACR. Increased left ventricular (LV) mass index, decreased global longitudinal strain (GLS) and LV ejection fraction, lower E/A ratio and e' velocity, and higher E/e' ratio were significantly associated with higher UACR on unadjusted analyses (p ≤ .01). After adjustment for covariates, UACR was only independently associated with lower GLS (tertile 3 = 20.7% vs. tertile 1 = 20.9%; p = .04). The results of hypertensive patients (p ≤ .04) but not normotensive patients (p ≥ .16) were similar to those of the total cohort. Subgroup analyses revealed similar results in patients without coronary artery disease, or without LV hypertrophy, or without diabetes. In conclusion, increased UACR is associated with worse subclinical systolic function in Chinese hypertensive patients but not in normotensive participants.

The Cardiotonic Steroid Marinobufagenin Is a Predictor of Increased Left Ventricular Mass in Obesity: The African-PREDICT Study

The endogenous Na+/K+-ATPase inhibitor, marinobufagenin (MBG), strongly associates with salt intake and a greater left ventricular mass index (LVMi) in humans and was shown to promote cardiac fibrosis and hypertrophy in animals. The adverse effects of MBG on cardiac remodeling may be exacerbated with obesity, due to an increased sensitivity of Na+/K+-ATPase to MBG. This study determined whether MBG is related to the change in LVMi over time in adults with a body mass index (BMI) ≥30 kg/m2 (obese) and <30 kg/m2 (non-obese). The study followed 275 healthy participants (aged 20-30 years) from the African-Prospective study on the Early Detection and Identification of Cardiovascular disease and Hypertension (African-PREDICT) study over 4.5 years. At baseline, we measured 24 h urine MBG excretion. MBG levels were positively associated with salt intake. LVMi was determined by two-dimensional echocardiography at baseline and after >4.5 years. With multivariate adjusted analyses in obese adults (N = 56), we found a positive association of follow-up LVMi (Adjusted (Adj.) R2 = 0.35; Std. β = 0.311; p = 0.007) and percentage change in LVMi (Adj. R2 = 0.40; Std. β = 0.336; p = 0.003) with baseline MBG excretion. No association of LVMi (Adj. R2 = 0.37; p = 0.85) or percentage change in LVMi (Adj. R2 = 0.19; p = 0.68) with MBG excretion was evident in normal weight adults (N = 123). These findings suggest that obese adults may be more sensitive to the adverse cardiac effects of MBG and provide new insight into the potential role of dietary salt, by way of MBG, in the pathogenesis of cardiac remodeling in obese individuals.

Von Willebrand factor, its cleaving protease (ADAMTS13), and inflammation in young adults: The African-PREDICT study

BACKGROUND

The role of inflammation in the early development of vascular dysfunction remains complex. Interleukin-6 (IL-6) and C-reactive protein (CRP) can cause an acute imbalance in the von Willebrand factor (vWF)-ADAMTS13 interaction, indicating a possible link between markers of haemostasis and low-grade inflammation. To better understand these inter-relationships in the early phases of disease development, we investigated whether vWF and ADAMTS13 associate with the pro-inflammatory markers, IL-6 and CRP in healthy young adults. We considered the role of blood types, sex and race on these relationships.

METHODS

In healthy black and white men and women (n = 1113; 24 ± 5 years; no previous diagnosis or medication use for chronic diseases) we analysed von Willebrand factor antigen (vWF_ag), ADAMTS13, IL-6 and CRP, and grouped blood types as non-O (A, B and AB) and O. Covariates included socioeconomic status, age, estimated glomerular filtration rate, 24-hour systolic blood pressure, waist circumference, glucose, total cholesterol, platelet count, γ-glutamyl transferase and total energy expenditure.

RESULTS

In the total group, vWF_ag was highest in the third tertile of both IL-6 and CRP (p ≤ 0.014), while ADAMTS13 was lowest in the third compared to the first IL-6 tertile (p = 0.006). In multivariate regression, vWF_ag associated positively with IL-6 (Adj R² = 0.169; β = 0.123; p = 0.001) and CRP (Adj R² = 0.163; β=0.094; p = 0.019) in the total group, in the O blood group (all p ≤ 0.051) and white men (all p ≤ 0.035). ADAMTS13 associated negatively with IL-6 (Adj R² = 0.053; β = -0.154; p = 0.015) and CRP (Adj R² = 0.055; β = -0.177; p = 0.009), only in the O blood group.

CONCLUSIONS

Markers of haemostasis associated independently with low-grade inflammation in the O type blood group and white men. An interplay between the haemostatic and inflammatory systems may already exist in young healthy adults and is dependent on blood groups, sex and race. This extends our understanding on the role of inflammation in the early development of vascular dysfunction prior to cardiovascular compromise.

Iodine nutrition status and its association with microvascular complications in urban dwellers with type 2 diabetes

Background

The principal function of iodine acts on thyroid function, but in recent years, the role of iodine deficiency in metabolism has also been gradually revealed. We aimed to investigate the current status of iodized salt consumption and urinary iodine concentration (UIC) in an urban Chinese population with type 2 diabetes, and to further explore whether UIC was associated with diabetic microvascular complications.

Methods

Four thousand five hundred fifty-nine subjects with diabetes from 7 communities in downtown Shanghai were enrolled in the cross-sectional Metal Study in 2018. UIC was detected using an inductively coupled plasma-mass spectrometer. Diabetic kidney disease (DKD) was defined as urinary albumin-to-creatinine ratio (UACR) > 30 mg/g or estimated glomerular filtration rate < 60 mL/min/1.73 m². Diabetic retinopathy (DR) was evaluated by high-quality fundus photographs and was remotely read by ophthalmologist.

Results

The median UIC of subjects with diabetes was 115.4 μg/L (78.9–170.8) in downtown Shanghai. Among all the subjects, 52.7% consumed non-iodized salt and 40.4% were iodine deficient. Iodine deficiency (UIC < 100 μg/L) was associated with an increased odds of DKD (OR 1.17; 95%CI 1.01–1.37) after adjustment for age, sex, education, current smokers, BMI, HbA1c, duration of diabetes, dyslipidemia, thyroid-stimulating hormone and free thyroxine. No association was observed between UIC and DR after multivariable adjustment.

Conclusions

A concerning number of subjects with diabetes consumed non-iodized salt and suffered from iodine deficiency in coastal regions of China. Low UIC might be a risk factor for DKD, which should be further confirmed by longitudinal prospective studies.

Applying the new intensive blood pressure categories to a nondialysis chronic kidney disease population: the Prevalence, Awareness and Treatment Rates in Chronic Kidney Disease Patients with Hypertension in China survey

BACKGROUND

The 2017 high blood pressure (BP) clinical practice guideline reported by the American College of Cardiology/American Heart Association put forward new categories of BP. This study aimed to assess the applicability of the new guideline in a nondialysis chronic kidney disease (CKD) population.

METHODS

This is a nationwide, multicenter, cross-sectional study with a large sample. A total of 8927 nondialysis CKD patients in 61 tertiary hospitals in all 31 provinces, municipalities and autonomous regions of China (except Hong Kong, Macao and Taiwan) were analyzed. The categories of BP were defined as normal BP (<120/80 mmHg), elevated BP [systolic BP (SBP) 120-130 and diastolic BP (DBP) <80 mmHg], and Stage 1 (SBP 130-139 or DBP 80-89 mmHg) and Stage 2 (SBP ≥140 or DBP ≥90 mmHg) hypertension. The prevalence and control of hypertension were estimated using a new definition, and the association between the main target organs' injury and new categories of BP was analyzed.

RESULTS

The prevalence, awareness and treatment of hypertension in nondialysis CKD patients were 79.8, 72.4 and 68.3%, respectively. Approximately 11.9% had BP <130/80 mmHg and 6.6% had BP <120/80 mmHg. Subgroups by categories of BP had significant differences in age, sex, body mass index category, primary cause and CKD stage (P < 0.001). After multivariable adjustment, only Stage 2 hypertension was associated with decreased renal function [odds ratio (OR) 2.4, 95% confidence interval (CI) 1.9-3.0, P < 0.001], cardiovascular disease (OR 2.0, 95% CI 1.3-3.1, P = 0.001) and cerebrovascular disease (OR 2.7, 95% CI 1.2-5.8, P = 0.015).

CONCLUSIONS

Using the new definition of hypertension, the higher prevalence and lower control of hypertension were shown in nondialysis CKD participants. More studies are necessary to confirm the applicability of new categories of BP in CKD population because only Stage 2 hypertension showed statistical association with the main target organs' injury.

Correlations between indices of dynamic components of ambulatory blood pressure and renal damage in elderly Chinese male with essential hypertension

OBJECTIVE

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) is an accurate method to document changes in blood pressure (BP) and is more predictive than office and home BP monitoring for cardiovascular outcomes in elderly people. We aimed to determine the relationship between ABPM indices and renal damage in elderly Chinese male patients with essential hypertension.

METHODS

We investigated 998 Chinese men (mean age of 78.44 ± 12.02 years) with essential hypertension. Renal function, laboratory testing, and ABPM, including ABP, BP variability, and BP circadian rhythms were investigated. Data were shown according to BP controlling status. The relationships between ABPM indices and renal damage [expressed by urine protein, urine albumin/creatinine ratio (uACR), estimated glomerular filtration rate (eGFR), blood urea nitrogen (BUN)] were assessed using multiple regression analysis.

RESULTS

After adjustments for age, common cardiovascular risk factors, and medications, uACR level was positively associated with 24-h mean systolic blood pressure (SBP), 24-h mean pulse pressure (PP), and 24-h SBP percent time of elevation. eGFR level was negatively associated with the 24-h mean SBP and 24-h mean PP. BUN level was positively correlated with the 24-h mean SBP, 24-h mean PP, and 24-h SBP percent time of elevation, whereas the BUN level was negatively associated with the 24-h DBP SD.

CONCLUSION

The ABPM indices associated with renal damage may be regarded as an early predictive marker for renal function impairment in Chinese elderly male patients with hypertension.

Fine particulate matter exposure and renal function: A population-based study among pregnant women in China

BACKGROUND

Fine particulate matter (PM_2.5) is the most serious environmental threat worldwide. The nephrotoxicity of PM_2.5 has been demonstrated in older adults, but no study has addressed the impacts of PM_2.5 exposure on renal function in pregnant women, who are recognized to be vulnerable and susceptible to PM_2.5 exposure.

OBJECTIVE

To evaluate whether exposures to PM_2.5 total mass and its chemical constituents were associated with reduced renal function among pregnant women in China.

METHODS

We measured serum concentrations of urea nitrogen (UN), uric acid (UA) and creatinine for 10,052 pregnant women in Shanghai, China. Exposures to PM_2.5 total mass and its 5 key chemical constituents during the whole pregnancy and each trimester of pregnancy was represented by satellite-based models.

RESULTS

Exposures to PM_2.5 total mass and its chemical constituents of organic matter (OM), black carbon (BC), nitrate (NO₃^-) and ammonium (NH₄⁺) were positively associated with serum levels of UN and UA, and negatively associated with estimated glomerular filtration rate (eGFR). An interquartile rang (IQR) increase in PM_2.5 total mass, OM, BC, NO₃^- and NH₄⁺ exposure in third trimester was associated with 1.33 (β = -1.33, 95% CI, -1.79, -0.87), 1.67 (β = -1.67, 95% CI, -2.26, -1.07), 1.29 (β = -1.29, 95% CI,-1.89, -0.70), 1.16 (β = -1.16, 95% CI,-1.66, -0.65) and 0.76 (β = -0.76, 95% CI, -1.08, -0.44) mL/min/1.73 m² decrease in eGFR, respectively.

CONCLUSION

We concluded that exposures to PM_2.5 during pregnancy were associated with decreased renal function among pregnant women.

Associations between abdominal obesity indices and diabetic complications: Chinese visceral adiposity index and neck circumference

Background and aims

Obesity, especially abdominal obesity, has been considered a risk factor for diabetic complications. Many abdominal obesity indices have been established, including neck circumference (NC), waist-to-hip ratio (WHR), lipid accumulation product (LAP), visceral adiposity index (VAI) and the Chinese visceral adiposity index (CVAI). However, studies investigating the associations between these indices and diabetic complications are limited. The objective of this study was to investigate the associations of the abdominal obesity indices with cardiovascular and cerebrovascular disease (CVD), diabetic kidney disease (DKD) and diabetic retinopathy (DR).

Methods

A total of 4658 diabetic participants were enrolled from seven communities in Shanghai, China, in 2018. Participants completed questionnaires and underwent blood pressure, glucose, lipid profile, and urine albumin/creatinine ratio measurements; fundus photographs; and anthropometric parameters, including height, weight, waist circumference (WC), NC and hip circumference (HC).

Results

In men, a one standard deviation (SD) increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.35; 95% CI 1.13, 1.62) and DKD (OR 1.38; 95% CI 1.12, 1.70) (both P < 0.05). In women, a one SD increase in CVAI level was significantly associated with a greater prevalence of CVD (OR 1.32; 95% CI 1.04, 1.69) and DKD (OR 2.50; 95% CI 1.81, 3.47) (both P < 0.05). A one SD increase in NC was significantly associated with a greater prevalence of CCA plaque in both men (OR 1.26; 95% CI 1.10, 1.44) and women (OR 1.20; 95% CI 1.07, 1.35). These associations were all adjusted for potential confounding factors.

Conclusions

CVAI was most strongly associated with the prevalence of CVD and DKD among the abdominal obesity indices, and NC was unique associated with the prevalence of CCA plaque in Chinese adults with diabetes.

Trial registration ChiCTR1800017573, www.chictr.org.cn. Registered 04 August 2018.

Neutrophil-to-lymphocyte ratio as an independent inflammatory indicator of poor prognosis in IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is achronic immuno-inflammatory progressive disease. Several systemic inflammatory indicators, mainly the neutrophil-to-lymphocyte ratio (NLR), are regarded as valuable markers for many diseases, such as IgA vasculitis and chronic kidney disease. Here, we investigated multiple peripheral blood indicators in a large IgAN registry with regular follow-up to evaluate their effects on IgAN phenotypes and progression.

METHODS

Totally, 1151 IgAN patients with regular follow-up, and 251 healthy volunteers were enrolled. Complete blood count test results, including counts of white blood cells (WBC), neutrophils (NE), lymphocyte (LY), and platelets (PLT), were collected from medical records. Then, NLR and PLR were calculated.

RESULTS

IgAN patients presented with increased WBC, NE, NLR and PLR levels and decreased LY levels compared with controls. In univariate survival analysis, WBC, NE and NLR showed significant associations with IgAN progression, and NLR had a higher area under the ROC curves than NE and WBC. When adjusted for well-known risk factors, NLR remained an independent risk factor for poor renal outcome in IgAN patients and performed better than NE. By using NLR 2.40 as cutoff point, IgAN patients were divided into two groups. IgAN patients in the high NLR group presented with lower eGFR, higher proteinuria, higher incidence of hypertension, and more severe pathological lesions, as well as lower event-free renal survival rate.

CONCLUSIONS

We found patients with IgAN had elevated NLR levels than healthy controls, and the easily available NLR in clinical practice could serve as an independent risk factor for IgAN progression.

The prevalence of chronic kidney disease in Iceland according to KDIGO criteria and age-adapted estimated glomerular filtration rate thresholds

Most epidemiological studies on chronic kidney disease (CKD) are based solely on estimated glomerular filtration rate (eGFR). Few studies have included proteinuria, while the chronicity criterion is usually omitted. To explore this, we examined the prevalence of CKD stages 1-5 in Iceland based on multiple markers of kidney damage. All serum creatinine values, urine protein measurements and diagnostic codes for kidney diseases and comorbid conditions for people aged 18 years and older were obtained from electronic medical records of all healthcare institutions in Iceland in 2008-2016. CKD was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline using diagnoses indicative of a chronic kidney disease, proteinuria and/or an eGFR under 60 mL/min/1.73 m² for over three months. Mean annual age-standardized prevalence of CKD stages 1-5 was calculated based on the KDIGO criteria and age-adapted eGFR thresholds from 2,120,147 creatinine values for 218,437 individuals, 306,531 proteinuria measurements for 86,364 individuals and 6973 individuals carrying a kidney disease diagnosis. Median age was 63 years (range, 18-106) and 47% were male. The mean annual age standardized CKD prevalence was 5.13% for men and 6.75% for women using the KDIGO criteria but by age-adapted eGFR cut-offs, the prevalence was 3.27% for men and 4.01% for women. Thus, our nationwide study, defining CKD in Iceland with strict adherence to the KDIGO criteria, demonstrates a lower prevalence of CKD than anticipated from most previous studies.

Lower eGFR is associated with increased probability of liver fibrosis in Chinese diabetic patients

BACKGROUND

Kidney dysfunction is linked to nonalcoholic fatty liver disease (NAFLD) progression including fibrosis, steatosis, or inflammation. We aimed to explore whether lower levels of estimated glomerular filtration rate (eGFR) was associated with increased probability of liver fibrosis.

METHODS

Two thousand six hundred eighty-nine subjects enrolled from Shanghai, China, were included in this study. NAFLD fibrosis score (NFS) was used to risk stratify NAFLD patients for fibrosis. eGFR was used to assess kidney function. The association of eGFR level with elevated NFS, and thus high risk of fibrosis, was analysed by linear regression and multinomial logistic regression. The predictive power of eGFR was evaluated via receiver operating characteristic (ROC) curve.

RESULTS

A negative association was found between eGFR and NFS (B = -0.21, 95% CI, -0.37 to -0.04, P = .016). As eGFR quartiles decreased, the prevalence of probable fibrosis increased after adjusting for age, sex, current smoking, waist circumference, duration of diabetes, HbA_1c , hypertension, dyslipidaemia, and homeostasis model assessment index of insulin resistance (HOMA-IR) (Q4: reference; Q3: 1.49, 95% CI, 0.82-2.71; Q2: 1.88, 95% CI, 0.97-3.67; Q1: 2.70, 95% CI, 1.36-5.37, P_{for trend} = .002, 1SD increment: 0.73, 95% CI, 0.58-0.92). The eGFR level can be an effective indicator in differentiating patients with probable presence of fibrosis from those without (AUROC: 0.71, cut-off point: 92.78 mL/min/1.73 m² , P < .001).

CONCLUSIONS

Lower levels of eGFR were associated with higher NFS and thus greater risk of presence of fibrosis in patients with NAFLD and T2DM. Individuals with NAFLD and diabetes should carefully monitor eGFR and receive regular urinalysis, especially when advanced fibrosis is suspected.

Clinical characteristics of acute glomerulonephritis with presentation of nephrotic syndrome at onset in children

BACKGROUND

Acute glomerulonephritis (AGN) is a common disease in children, which places a huge burden on developing countries. The prognosis of it may not always be good. However, the clinical characteristics of AGN with nephrotic syndrome (NS) at onset have not been fully clarified.

METHODS

One hundred and thirteen cases were analyzed retrospectively. Clinical data, pathological results and prognosis between AGN with NS (AGN-NS) and AGN without NS (AGN-no-NS) were compared.

RESULTS

Twenty (17.7%) of 113 patients were AGN-NS. The patients with AGN-NS were more likely to have hypertension (55.0% vs. 25.8%) and acute kidney injury (AKI) (50.0% vs. 17.2%). AKI was significantly related to the manifestation of AGN-NS in children (OR = 3.812, P = 0.040). Compared with the AGN-no-NS, the immunosuppressive treatments were more common in AGN-NS. A more severe pathological grade was significantly related to lower C3 fraction, estimated glomerular filtration rate (eGFR), and AKI, but not to the performance of AGN-NS. There was no difference in prognosis between the two groups.

CONCLUSIONS

AKI was significantly associated with AGN-NS. The prognosis of AGN-NS and AGN-no-NS in our study was almost good. Given the fact that AGN-NS patients are more likely to use immunosuppressive therapy, the long-term outcome of AGN-NS warrants further research.

White-coat hypertension and incident end-stage renal disease in patients with non-dialysis chronic kidney disease: results from the C-STRIDE Study

Background

Controversy remains whether white coat hypertension (WCH) is associated with renal prognosis in patients with chronic kidney disease (CKD).

Methods

In the present multicenter, prospective study, we analyzed data of participants with CKD stage 1–4 from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE). WCH was defined according to two criteria as follows: A, clinical blood pressure (BP) ≥ 140/90 mm Hg and average 24-h ambulatory BP < 130/80 mm Hg; B, clinical BP ≥ 130/80 mm Hg and daytime ambulatory BP < 130/80 mm Hg. Renal outcome was defined as initiation of renal replacement therapy. The association of WCH with renal events was evaluated by Cox regression model.

Results

A total of 1714 patients with CKD were included in the present analysis. The mean age of the population was 48.9 ± 13.8 years and 56.8% were men. The mean baseline estimated glomerular filtration rate (eGFR) was 52.2 ± 30.1 ml/min/1.73 m² and urinary protein was 1.0 (0.4, 2.4) g/day. The overall prevalence of WCH was 4.7% and 16.6% according to criteria A and B, respectively. Incidence rates of renal events were 49.58 and 26.51 according to criteria A and B, respectively, per 1000 person-years during a median follow-up of 4.8 years. After full adjustment, WCH was associated with an increased risk of renal event (criterion A: hazard ratio 2.36, 95% confidence interval 1.29–4.34; for criterion B: hazard ratio 1.90, 95% confidence interval 1.04–3.49) compared with patients with normal BP.

Conclusions

WCH is associated with a greater risk for renal events in non-dialysis dependent Chinese patients with CKD.

Short-Term Systolic Blood Pressure Variability and Kidney Disease Progression in Patients With Chronic Kidney Disease: Results From C-STRIDE

Background

It is unclear whether short‐term blood pressure variability is associated with renal outcomes in patients with chronic kidney disease.

Methods and Results

This study analyzed data from participants in the C‐STRIDE (Chinese Cohort Study of Chronic Kidney Disease) who had chronic kidney disease stages 1 to 4. Short‐term blood pressure variability was measured by calculating the weighted SD (w‐SD) of systolic blood pressure (SBP). Renal outcomes were defined as dialysis initiation and/or transplantation. Risk factors associated with w‐SD of SBP were evaluated by linear regression. Associations of short‐term SBP variability with renal outcomes were evaluated by Cox regression. In total, 1421 patients with chronic kidney disease were included in this study (mean age, 49.4±13.6 years; 56.2% men; estimated glomerular filtration rate, 50.5±29.3 mL/min per 1.73 m²; proteinuria, 0.9 [0.3–2.0] g/d). Mean w‐SD of SBP was 12.6±4.4 mm Hg. w‐SD of SBP was independently associated with older age, 24‐hour SBP, blood pressure circadian pattern, and angiotensin II receptor blocker treatment. During a median follow‐up of 4.9 years, 237 patients developed renal outcomes (37.01 per 1000 patient‐years). The incidence rate increased across the quartiles of w‐SD (log‐rank P=0.005). w‐SD of SBP was associated with an increased risk of renal outcomes, both as a continuous variable (hazard ratio [HR], 1.47; 95% CI, 1.09–1.99) and as a categorical variable (quartile 4 versus quartile 1: HR, 1.60; 95% CI, 1.08–2.36), independent of 24‐hour SBP, daytime SBP, and nighttime SBP.

Conclusions

Short‐term SBP was independently associated with the risk of dialysis initiation and/or transplantation in patients with chronic kidney disease.

Prevalence and Risk Factors for CKD in the General Population of Southwestern Nicaragua

BACKGROUND

Studies have described Mesoamerican nephropathy among agricultural workers of El Salvador and northwestern Nicaragua. Data on prevalence and risk factors for CKD beyond agricultural workers and in other regions in Nicaragua are sparse.

METHODS

We recruited participants from 32 randomly selected communities in the Department of Rivas's ten municipalities in two phases. In phase 1, we screened participants using a field-based capillary creatinine measuring system and collected self-reported information on lifestyle and occupational, exposure, and health histories. Two years later, in phase 2, we enrolled 222 new participants, performing serum creatinine testing in these participants and confirmatory serum creatinine testing in phase 1 participants.

RESULTS

We enrolled 1242 of 1397 adults (89%) living in 533 households (median age 41 years; 43% male). We confirmed CKD (eGFR<60 ml/min per 1.73 m²) in 53 of 1227 (4.3%) evaluable participants. In multivariable testing, risk factors for prevalent CKD included age (odds ratio [OR], 1.92; 95% confidence interval [95% CI], 1.89 to 1.96) and self-reported history of hypertension (OR, 1.95; 95% CI, 1.04 to 3.64), diabetes (OR, 2.88; 95% CI, 1.40 to 5.93), or current or past work in the sugarcane industry (OR 2.92; 95% CI, 1.36 to 6.27).

CONCLUSIONS

Adjusted CKD prevalence was about 5% with repeat confirmatory testing in southwest Nicaragua, lower than in the northwest region. Risk factors included diabetes, hypertension, and current or prior work in the sugarcane industry but not in other forms of agricultural work. Formal CKD surveillance programs in Nicaragua are needed to assess the overall burden of CKD nationally, with a focus on agricultural workers.

Analysis of clinical and laboratory characteristics and pathology of lupus nephritis-based on 710 renal biopsies in China

OBJECTIVES

This study aimed to analyse the clinical and laboratory characteristics of different pathologic classifications of lupus nephritis (LN) patients in terms of age at systemic lupus erythematosus (SLE) diagnosis and nephritis onset.

METHOD

Clinical, laboratory, and pathological data of 710 LN patients diagnosed by renal biopsy at our institution between 2000 and 2018 were retrospectively analysed. Patients were divided into the different pathological classification groups; childhood-, adult- and elderly-onset SLE groups and early- and late-onset LN groups.

RESULTS

Class IV occurred most frequently and had the lowest complement C3 level. There was an obvious increase in active index in class IV and class V + IV. Patients with class VI showed some clinical characteristics similar to end-stage renal disease. Patients with proliferative nephritis were younger at SLE diagnosis and had higher blood pressure, higher frequency of proteinuria and urinary erythrocyte and lower haemoglobin and complement C3. Pathologic classification between childhood-, adult- and elderly-onset SLE patients or between early- and late-onset LN patients was not significantly different. Elderly-onset SLE patients had the highest chronic index (CI), IgA, IgG and Sjögren's syndrome A antibodies and Sjögren's syndrome B antibodies rates, whereas late-onset LN patients showed significantly higher CI, haemoglobin, complement C3 and C4 but lower uric acid, IgM and IgG.

CONCLUSIONS

LN patients present with different clinical and laboratory characteristics according to pathological classification, age at SLE diagnosis and nephritis onset. These results might be valuable for estimating the pathology and guiding treatment and prognosis. Key Points • Patients with proliferative nephritis have more severe immune disorders, worse renal function and stronger inflammatory state. • The elderly-onset SLE patients showed a poorer condition. • The late-onset LN patients might have a more stable status.

Dialysis timing may be deferred toward very late initiation: An observational study

The optimal timing to initiate dialysis among patients with an estimated glomerular filtration rate (eGFR) of <5 mL/min/1.73 m2 is unknown. We hypothesized that dialysis initiation time can be deferred in this population even with high uremic burden. A case-crossover study with case (0-30 days before dialysis initiation [DI]) and control (90-120 days before DI) periods was conducted in 1,079 hemodialysis patients aged 18-90 years at China Medical University Hospital between 2006 and 2015. The uremic burden was quantified based on 7 uremic indicators that reached the predefined threshold in case period, namely hemoglobin, serum albumin, blood urea nitrogen, serum creatinine, potassium, phosphorus, and bicarbonate. Dialysis timing was classified as standard (met 0-2 uremic indicators), late (3-5 indicators), and very late (6-7 indicators). Median eGFR-DI of the 1,079 patients was 3.4 mL/min/1.73 m2 and was 2.7 mL/min/1.73 m2 in patients with very late initiation. The median follow-up duration was 2.42 years. Antibiotics, diuretics, antihypertensive medications, and non-steroidal anti-inflammatory drugs (NSAIDs) were more prevalently used during the case period. The fully adjusted hazards ratios of all-cause mortality for the late and very late groups were 0.97 (95% confidence interval 0.76-1.24) and 0.83 (0.61-1.15) compared with the standard group. It is safe to defer dialysis initiation among patients with chronic kidney disease (CKD) having an eGFR of <5 mL/min/1.73 m2 even when patients having multiple biochemical uremic burdens. Coordinated efforts in acute infection prevention, optimal fluid management, and prevention of accidental exposure to NSAIDs are crucial to prolong the dialysis-free survival.

Kidney Disease, Race, and GFR Estimation

Assessment of GFR is central to clinical practice, research, and public health. Current Kidney Disease Improving Global Outcomes guidelines recommend measurement of serum creatinine to estimate GFR as the initial step in GFR evaluation. Serum creatinine is influenced by creatinine metabolism as well as GFR; hence, all equations to estimate GFR from serum creatinine include surrogates for muscle mass, such as age, sex, race, height, or weight. The guideline-recommended equation in adults (the 2009 Chronic Kidney Disease Epidemiology Collaboration creatinine equation) includes a term for race (specified as black versus nonblack), which improves the accuracy of GFR estimation by accounting for differences in non-GFR determinants of serum creatinine by race in the study populations used to develop the equation. In that study, blacks had a 16% higher average measured GFR compared with nonblacks with the same age, sex, and serum creatinine. The reasons for this difference are only partly understood, and the use of race in GFR estimation has limitations. Some have proposed eliminating the race coefficient, but this would induce a systematic underestimation of measured GFR in blacks, with potential unintended consequences at the individual and population levels. We propose a more cautious approach that maintains and improves accuracy of GFR estimates and avoids disadvantaging any racial group. We suggest full disclosure of use of race in GFR estimation, accommodation of those who decline to identify their race, and shared decision making between health care providers and patients. We also suggest mindful use of cystatin C as a confirmatory test as well as clearance measurements. It would be preferable to avoid specification of race in GFR estimation if there was a superior, evidence-based substitute. The goal of future research should be to develop more accurate methods for GFR estimation that do not require use of race or other demographic characteristics.

The relationship between serum fibroblast growth factor 23, Klotho, and lumbar spine bone mineral density in northern Chinese postmenopausal women

OBJECTIVES

Changes in serum protein levels of fibroblast growth factor 23 (FGF23) and Klotho resulting from bone metabolism are still controversial. The purpose of this study was to observe the relationship between FGF23 and Klotho serum proteins and lumbar spine bone mineral density (LBMD) in northern Chinese postmenopausal women.

METHODS

This was a community-based cross-sectional study carried out in Shenyang, a northern Chinese city. The study included 355 postmenopausal women with an average age of 62.92 ± 8.78 years. FGF23 and Klotho serum proteins were measured using a sandwich enzyme immunoassay. LBMD was examined using dual-energy X-ray absorptiometry. Pearson's correlation and regression analyses were performed to investigate the associations among them.

RESULTS

The LgKlotho was positively correlated with LBMD (r = 0.105). There was a linear relationship between LgKlotho serum levels and LBMD (P = 0.007) after adjusting for BMI, and the relationship still existed after adjustments for many confounding variables (P = 0.045), including age, BMI, systolic blood pressure, diastolic blood pressure, total protein, total bilirubin, high-density lipoprotein cholesterol, fasting blood glucose, serum calcium, estimated glomerular filtration rate, serum uric acid, estradiol, cigarette smoking, alcohol consumption, milk intake, calcium and vitamin D supplements, physical exercise, and fracture history in postmenopausal women. FGF23 serum levels were, however, not significantly associated with LBMD.

CONCLUSIONS

Klotho was positively correlated with LBMD, and there was a linear relationship between Klotho serum protein levels and LBMD; however, the levels of serum Klotho were not independently associated with reduced LBMD in northern Chinese postmenopausal women. Moreover, serum FGF23 levels were not significantly related to LBMD in this sample population.

Repeated measurements of serum urate and mortality: a prospective cohort study of 152,358 individuals over 8 years of follow-up

BACKGROUND

Longitudinal evidence on change of serum urate level with mortality risk is limited as prior studies have a measurement of serum urate at a single time point. Further, the combined effect of serum urate and systemic inflammation on mortality is unknown.

METHODS

We conducted a prospective cohort study of 152,358 participants (122,045 men and 30,313 women) with repeated measurements of serum urate in 2006, 2008, 2010, and 2012 (107,751 participants had all four measurements of serum urate). We used the Cox proportional hazard model to examine the association between cumulative average and changes in serum urate with mortality. The combined effect of serum urate and systemic inflammation was determined by testing the interaction of serum urate and high-sensitive C-reactive protein (hs-CRP) in relation to mortality risk.

RESULTS

During a median follow-up of 8.7 (interquartile range 6.3-9.2) years, we identified 7564 all-cause deaths, 1763 CVD deaths, 1706 cancer deaths, and 1572 other deaths. We observed U-shaped relationships of cumulative average serum urate with all-cause mortality, cardiovascular mortality, and other mortalities. Compared with participants with stable serum urate, those with greater increases in serum urate had a 1.7-fold elevated mortality (hazard ratio (HR) = 1.66, 95% confidence interval (CI) = 1.49-1.84), and those with decreased serum urate had a 2-fold elevated mortality risk (HR = 2.14, 95% CI 1.93-2.37). Participants with both hyperuricemia and hs-CRP had 1.6 times higher mortality, compared with those with low serum urate and hs-CRP levels (HR = 1.56, 95% CI 1.37-1.76).

CONCLUSIONS

We observed a U-shaped relationship of long-term cumulative average serum urate with all-cause mortality, cardiovascular mortality, and other mortalities. Compared with participants with relatively stable serum urate levels, a greater increase or decrease in serum urate was associated with elevated mortality. Participants with both hyperuricemia and high systemic inflammation had the greatest mortality risk compared with those with low serum urate and low hs-CRP levels.

Prevalence and Risk Factors of Chronic Kidney Disease among Type 2 Diabetes Patients: A Cross-Sectional Study in Primary Care Practice

This cross-sectional study aimed to investigate the prevalence and risk factors of chronic kidney disease (CKD) among 1,096 primary care type 2 diabetes (T2DM) patients in northern Thailand between October 2016 and September 2017. CKD was defined as estimated glomerular rate filtration values of <60 mL/min/1.73 m². Prevalence with confidence intervals across CKD advanced stages 3–5 were estimated. Factors associated with CKD were evaluated by multivariate logistic regression. The overall prevalence of CKD was 24.4% (21.9–27.0), with severities of 11.4% (9.7–13.4), 6.8% (5.5–8.5), 4.6% (3.5–6.0), and 1.6% (1.0–2.5) for stages 3 A, 3B, 4, and 5, respectively. Regarding age and glycaemic control, individuals older than 75 years and those with a haemoglobin A1c ≥ 8% had the highest prevalence of 61.3% (51.7–70.1) and 38.6% (34.3–43.2), respectively. The multivariable logistic regression model explained 87.3% of the probability of CKD. The six independent significant risk factors of CKD were older age, retinopathy, albuminuria, haemoglobin A1c ≥ 7%, anaemia, and uric acid>7.5 mg/dL. A relatively high prevalence of CKD, especially in older patients and those with diabetic complications-related to poor glycaemic control, was encountered in this primary care practice. Early identification may help to target optimise care and prevention programs for CKD among T2DM patients.

Association between dietary patterns with kidney function and serum highly sensitive C-reactive protein in Tehranian elderly: An observational study

BACKGROUND

Accumulating evidence suggests that diet is associated with kidney function. This study was carried out to examine the association between a posteriori dietary patterns and kidney function in older adults.

MATERIALS AND METHODS

In a cross-sectional study, 266 older adults, aged 60-83 years, were included. Anthropometric measures were recorded. Biochemical measurements of blood and urine samples were measured. Information on diet was collected using a validated semi-quantified food frequency questionnaire with 168 food items and factor analysis performed to derive major dietary patterns. Estimated glomerular filtration rate (eGFR) was calculated using the chronic kidney disease (CKD) Epidemiology Collaboration equation.

RESULTS

A total of 266 participants with mean body mass index (BMI) 29.75 ± 4.53 kg/m2 and age, 66.2 ± 5.3 years, were included in the current study. Three major dietary patterns were identified using factor analysis based on intake data (28% of the total variance of food intake in the population). After adjustment for age, sex, BMI, and energy intake, we found a positive significant relationship between the first pattern and eGFR (P = 0.031). A positive significant association between adherence to the traditional dietary pattern and urine creatinine was also observed (P = 0.035). In addition, in logistic regression model and after control for covariates, a positive association was observed between adherence to traditional dietary pattern with odds of eGFR < 60 ml/min/1.73 m2 (P = 0.043) and urinary albumin-to-creatinine ratio ≥ 30 mg/g (P = 0.038).

CONCLUSION

It is concluded that higher adherence to the healthy dietary pattern may improve renal function while Iranian traditional pattern was associated with significantly increased odds of incident CKD and albuminuria.

Complement C3 and Nonalcoholic Fatty Liver Disease in Chronic Kidney Disease Patients: A Pilot Study

CONTEXT

Evidences have suggested complement C3 is a biomarker for nonalcoholic fatty liver disease (NAFLD) in the general population.

OBJECTIVE

The present study was conducted to explore the predictive function of C3 for NAFLD in chronic kidney disease (CKD) patients.

DESIGN, SETTING, AND PARTICIPANTS

CKD patients were recruited for evaluation of their liver function, kidney function, serum lipids, glycated hemoglobin, blood, and immune function. The glomerular filtration rate was calculated using the CKD-EPI equation. NAFLD was diagnosed according to predefined ultrasonographic criteria.

RESULTS

A total of 648 consecutive CKD patients were included, with 216 (33.3%) patients diagnosed with NAFLD. The NAFLD group had significant higher levels of serum protein, serum albumin, triglycerides, glycated hemoglobin, complement C3, hemoglobin (p = 0.001), alanine aminotransferase (p = 0.002), estimated glomerular filtration rate (p = 0.007), and C4 (p = 0.043) and lower levels of cystatin C, β2-microglobulin, proteinuria (p = 0.001), and high-density lipoprotein cholesterol (p = 0.008). In a logistic regression model, only complement C3 (OR = 1.003; 95% CI 1.002-1.004, p = 0.001) was associated with a higher likelihood of being diagnosed with NAFLD. Finally, we constructed ROC curves for complement C3 for prediction of having NAFLD. The best cut-off for complement C3 was 993.5 mg/L and it yielded a sensitivity of 63.9% and a specificity of 70.1%.

CONCLUSION

Our study revealed that complement C3 can be used as a surrogate biomarker of NAFLD in CKD patients.

The Associations Between Gonadal Hormones and Serum Uric Acid Levels in Men and Postmenopausal Women With Diabetes

Introduction: In assessing the development of hyperuricemia in diabetic adults, the role of the sex steroid axis is underappreciated. Furthermore, dehydroepiandrosterone (DHEA) has been recommended as a nutritional supplement. However, is DHEA suitable for diabetic adults with hyperuricemia? This issue has received little attention. Aim: The objective of this study was to investigate the associations between gonadal hormones and uric acid (UA) levels in diabetic adults, paying particular attention to the association between DHEA and UA levels. Methods: We analyzed 4,426 participants out of 4,813 diabetic adults enrolled from seven communities in a cross-sectional survey conducted in 2018. Participants underwent several examinations, including assessments of anthropometric parameters, blood pressure, glucose, lipid profiles, UA, total testosterone (TT), estradiol (E2), the follicle-stimulating hormone (FSH), the luteinizing hormone (LH), and dehydroepiandrosterone (DHEA). Results: Among men and compared with individuals in the first quartile, participants in the fourth quartile of TT and FSH had odds of hyperuricemia that were significantly decreased by so much as 48 and 34%, respectively (both P < 0.05). However, participants in the fourth quartile of DHEA had 79% increased odds of hyperuricemia (P < 0.05). Among postmenopausal women, participants in the fourth quartile of DHEA, TT, and LH had odds of hyperuricemia that were significantly increased by 155, 99, and 76%, respectively (all P < 0.05). These associations were adjusted for potential confounding factors. Conclusions: Sex differences were found in the associations between gonadal hormones and UA levels in diabetic men and postmenopausal women, which should be monitored to prevent hyperuricemia when sex hormone treatment, especially DHEA, is administered. Further studies are needed.