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

Associations between different bilirubin subtypes and diabetic microvascular complications in middle-aged and elderly individuals

AIMS

Some studies have reported associations between bilirubin and diabetic microvascular complications. However, these studies focused only on total bilirubin (TBIL) without distinguishing different bilirubin subtypes. In this study, we aimed to investigate the associations of TBIL, direct bilirubin (DBIL) and indirect bilirubin (IBIL) levels with albuminuria/creatinine ratio (ACR) and the prevalence of diabetic retinopathy (DR) among diabetic adults.

METHODS

We analyzed 4368 individuals out of 4813 diabetic participants enrolled from seven communities in 2018 in a cross-sectional study. Participants underwent several checkups, including the measurement of anthropometric parameters, blood pressure, glucose, lipid profile, TBIL, DBIL, IBIL and ACR. DR was detected by high-quality fundus photographs and was remotely read by ophthalmologists.

RESULTS

Compared with the first quartile of DBIL, participants in the fourth quartile had a lower prevalence of high ACR (odds ratio (OR) 0.76; 95% confidence interval (CI) 0.59, 0.99) (p for trend < 0.05). Neither TBIL nor IBIL was associated with the prevalence of high ACR. In DR, higher DBIL and TBIL by one standard deviation was associated with a 19% (OR 0.81; 95% CI 0.69, 0.94) and a 12% (OR 0.88; 95% CI 0.78, 0.99) lower frequency of DR, respectively (both p for trend < 0.05). However, IBIL was not associated with the prevalence of DR. These associations were adjusted for potential confounding factors.

CONCLUSION

DBIL had a stronger association with high ACR and DR than TBIL or IBIL did in diabetic adults. The effect of DBIL on diabetic complications should be noted and investigated in further studies.

Thyroid Parameters and Kidney Disorder in Type 2 Diabetes: Results from the METAL Study

OBJECTIVE

Diabetic kidney disease is one of the most common microvascular complications of diabetes mellitus. We aimed to analyze the association of thyroid parameters with kidney disorders, especially in euthyroid participants.

METHODS

The data were obtained from a cross-sectional study, the METAL study. Thyroid parameters, including thyroid-stimulating hormone (TSH), free triiodothyronine (FT₃), free thyroxine (FT₄), triiodothyronine (T₃), thyroxin (T₄), thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb), of 4136 participants with type 2 diabetes were measured. Two structure parameters of thyroid homeostasis, including the sum activity of step-up deiodinases (SPINA-G_D) and thyroid secretory capacity (SPINA-G_T), and two pituitary thyrotropic function indices, including Jostel's TSH index (TSHI) and the thyrotroph thyroid hormone resistance index (TTSI), were also calculated. Kidney disorders were described according to the presence of reduced estimated glomerular filtration rate (eGFR) and/or higher urinary albumin to creatinine ratio (UACR).

RESULTS

The prevalence of kidney disorders increased with decreasing FT₃ or T₃ and increasing FT₄ or T₄ quartile levels (all P < 0.05). After full adjustment, linear regression showed that UACR levels were negatively associated with FT₃ and T₃ (P < 0.001). In addition, eGFR was positively associated with FT₃ and T₃ and was negatively associated with TSH and FT₄ levels and TgAb positivity (all P < 0.05). By using binary logistic regression, higher TSH and FT₄ and lower FT₃ and T₃ were associated with kidney disorders (all P < 0.05). Similar results were seen in sensitivity analyses, which were performed in 3035 euthyroid diabetic participants; however, TSH was no longer related to them. The area under the receiver operating characteristic curve (AUROC) of lower FT₃ for existing kidney disorder was greater than that for any other thyroid hormones (all P < 0.001). The cutoff value of FT₃ for reduced eGFR was 4.39 pmol/L. Regarding thyroid homeostasis parameters, SPINA-G_D was negatively associated with three statuses of kidney disorders, and TSHI and TTSI were positively associated with reduced eGFR (all P < 0.05).

CONCLUSIONS

Among patients with type 2 diabetes, elevated TSH and FT₄ (or T₄), lower FT₃ (or T₃), TgAb positivity, lower SPINA-G_D, and higher TSHI and TTSI were associated with kidney disorders. The lower FT₃, even within the normal range (<4.38 pmol/L), may be the factor most related to reduced eGFR compared with other thyroid hormones in diabetic patients.

Glomerular filtration rate estimated by the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation in type 1 diabetes based on genomic ancestry

BACKGROUND

Black individuals have a great risk of developing chronic kidney disease (CKD) that is associated with high morbimortality, so it is important to classify them into the correct renal function group. Some equations used to estimate glomerular filtration rate (eGFR) divide patients only into two categories: African Americans and non-African Americans. The CKD-EPI equation was tested only in African Americans, and not Black patients from other regions, and takes into consideration self-reported color-race instead of genomic ancestry (GA) to determine the use of the ethnic correction factor. So far, this equation has not been evaluated in admixed populations, such as the Brazilian, using the percentage of GA to decide to apply the correction factor. The purpose of our study was to compare, in patients with type 1 diabetes (T1D), the eGFR calculated without the use of the correction factor, with the values obtained using the correction factor in patients presenting 50% or more of African GA.

METHODS

This cross-sectional, multicenter study enrolled 1279 patients from all geographic regions of Brazil. The CKD-EPI equation was used and CKD was defined as eGFR < 60 ml/min. GA were inferred using a panel of 46 AIM-INDEL, afterwards patients presenting an African GA ≥ 50% were selected.

RESULTS

Initially, all patients with African GA ≥ 50% (n = 85) were considered as non-African Americans when calculating the eGFR and afterwards the ethnic correction factor was applied to recalculate the eGFR. CKD was present in 23 patients and 56.5% of them were redefined as having normal renal function after using the correction factor, mainly women [11 of the 13 patients (84.6%)], with GFR between 52-59.3 ml/min.

CONCLUSIONS

More than half of the patients in the study were reclassified to a normal renal function group, showing that GA may be an important tool to decide between the use of the ethnic correction factor in the CKD-EPI equation in a highly admixed population of patients with T1D. A large-scale study involving GA and eGFR in comparison to reference methods should be conducted to better establish whether or not the ethnic correction factor should be used in highly admixed populations.

Aging, Arterial Stiffness, and Blood Pressure Association in Chinese Adults

Arterial stiffness and blood pressure (BP) both increase with aging synchronously. Whether elevated BP results from thickening of arterial wall or vice versa is controversial in previous studies. This study included 17 862 participants without history of myocardial infarction, stroke, atrial fibrillation or flutter, or cancer and with brachial-ankle pulse wave velocity (baPWV) and BP measurements during 2010 to 2016. Age was calculated from the self-reported birthdate to the first date of baPWV examination. Mediation analyses were applied to assess the mediation effect by baPWV in the association between age and BP. Temporal relation between baPWV and BP was assessed by cross-lagged analyses among 1508 participants with repeated assessment of baPWV. We found that systolic BP increased 0.47 (95% CI, 0.45-0.49) mm Hg per 1 year older by the mediation effect of baPWV and that the direct effect of aging on systolic BP was -0.07 (95% CI, -0.09 to -0.05) mm Hg per 1 year older. The standard regression coefficient from baseline baPWV to follow-up systolic BP was 0.09 (95% CI, 0.04-0.15), which was greater than the standard regression coefficient from baseline systolic BP to follow-up baPWV (0.01; 95% CI, -0.04 to 0.06). Arterial stiffness mediated the positive association between aging and BP, and arterial stiffness might precede elevated BP. Clinical Trial Registration- URL: http://www.chictr.org.cn . Unique identifier: ChiCTR-TNRC-11001489.

Predictive Capabilities of Three Widely Used Pathology Classification Systems and a Simplified Classification (Beijing Classification) in Primary IgA Nephropathy

BACKGROUND/AIMS

Several pathological classification systems were commonly used in clinical practice to predict the prognosis of IgA nephropathy (IgAN). However, how prognostic value differs between these systems is unclear. The aim of this study was to compare the Lee grade, the Oxford classification, and the Haas classification and to find a simplified classification.

METHODS

We retrospectively analyzed IgAN cases diagnosed between January 2002 and December 2007. The endpoints were progression to end-stage renal disease (ESRD) or a ≥50% decline in estimated glomerular filtration rate (eGFR). The predictive capabilities were evaluated by comparing the ability of discrimination (continuous net reclassification) and calibration (Akaike information criterion [AIC]).

RESULTS

A total of 412 IgAN patients were included in the study. The average follow-up period was 80.62 ± 23.63 months. A total of 44 (10.68%) patients progressed to ESRD, and 70 (16.99%) patients showed a ≥50% decline in eGFR. All multivariate Cox regression models had limited power for high AIC values. The prognostic values of the Lee grade and the Oxford classification were higher than those of models containing only established baseline clinical indicators for progression to ESRD or a ≥50% decline in eGFR (Lee grade 0.50, 95% CI 0.21-0.74; Oxford classification 0.48, 95% CI 0.28-0.71). The prognostic value of the Haas classification was lower than that of the other pathological classification systems for progression to ESRD or a ≥50% decline in eGFR (Lee grade 0.53, 95% CI 0.23-0.92; Oxford classification 0.59, 95% CI 0.10-0.74). The prognostic value of hierarchical classification (Beijing classification) using M and T lesion was similar to the Oxford classification.

CONCLUSIONS

Both the Lee grade and the Oxford classification showed incremental prognostic values beyond established baseline clinical indicators. The Haas classification was slightly inferior to the Lee grade and the Oxford classification. The hierarchical classification (Beijing classification) using less pathological parameters does not lose predictive efficiency.

Novel associations between sex hormones and diabetic vascular complications in men and postmenopausal women: a cross-sectional study

Background

Associations between sex hormones and vascular remodeling have been extensively studied, but the results vary widely among different races and sex. We aimed to investigate whether total testosterone (TT), estrogen (E2), and dehydroepiandrosterone (DHEA) associate with macrovascular complications and diabetic kidney disease (DKD) among community-dwelling patients with diabetes.

Methods

A total of 4720 participants with type 2 diabetes were recruited from Shanghai, China. Common carotid artery (CCA) plaques and diameter were assessed by ultrasound. Cardiovascular disease (CVD) was defined by prior diagnosis of coronary heart disease, myocardial infarction or stroke. DKD was defined according to the ADA Guidelines.

Results

(1) In men, TT was negatively associated with CCA diameter (regression coefficient (β) − 0.044, 95% CI − 0.087, 0). E2 levels were positively associated with CVD and CCA plaque prevalence (OR 1.151, 95% CI 1.038, 1.277 and OR 1.13, 95% CI 1.017, 1.255, respectively). DHEA was negatively associated with CVD (OR 0.809, 95% CI 0.734, 0.893). In postmenopausal women, TT levels were negatively associated with CCA diameter (β − 0.046, 95% CI − 0.083, − 0.010) and positively associated with CVD (OR 1.154, 95% CI 1.038, 1.284). (2) In both men and postmenopausal women, TT levels were negatively associated with the albumin/creatinine ratio and DKD (β − 0.098, 95% CI − 0.154, − 0.043 and OR 0.887, 95% CI 0.790, 0.997 vs. β − 0.084, 95% CI − 0.137, − 0.031 and OR 0.822, 95% CI 0.731, 0.924, respectively) and DHEA levels were positively associated with DKD (OR 1.167, 95% CI 1.038, 1.313 vs. OR 1.251, 95% CI 1.104, 1.418, respectively).

Conclusions

Our study indicates that macrovascular complications were associated with low TT, DHEA and high E2 in men and with high TT in postmenopausal women. DKD was associated with low TT and high DHEA levels in both genders. Sex hormone replacement therapy requires careful and comprehensive consideration.

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

Electronic supplementary material

The online version of this article (10.1186/s12933-019-0901-6) contains supplementary material, which is available to authorized users.

A prospective cohort study on the pharmacokinetics of nivolumab in metastatic non-small cell lung cancer, melanoma, and renal cell cancer patients

BACKGROUND

Nivolumab is administered in a weight-based or fixed-flat dosing regimen. For patients with non-small cell lung cancer (NSCLC), a potential exposure-response relationship has recently been reported and may argue against the current dosing strategies. The primary objectives were to determine nivolumab pharmacokinetics (PK) and to assess the relationship between drug clearance and clinical outcome in NSCLC, melanoma, and renal cell cancer (RCC).

METHODS

In this prospective observational cohort study, individual estimates of nivolumab clearance and the impact of baseline covariates were determined using a population-PK model. Clearance was related to best overall response (RECISTv1.1), and stratified by tumor type.

RESULTS

Two-hundred-twenty-one patients with metastatic cancer receiving nivolumab-monotherapy were included of whom 1,715 plasma samples were analyzed. Three baseline parameters had a significant effect on drug clearance and were internally validated in the population-PK model: gender, BSA, and serum albumin. Women had 22% lower clearance compared to men, while the threshold of BSA and albumin that led to > 20% increase of clearance was > 2.2m² and < 37.5 g/L, respectively. For NSCLC, drug clearance was 42% higher in patients with progressive disease (mean: 0.24; 95% CI: 0.22-0.27 L/day) compared to patients with partial/complete response (mean: 0.17; 95% CI: 0.15-0.19 L/day). A similar trend was observed in RCC, however, no clearance-response relationship was observed in melanoma.

CONCLUSIONS

Based on the first real-world population-PK model of nivolumab, covariate analysis revealed a significant effect of gender, BSA, and albumin on nivolumab clearance. A clearance-response relationship was observed in NSCLC, with a non-significant trend in RCC, but not in melanoma. Individual pharmacology of nivolumab in NSCLC appears important and should be prospectively studied.

Potential Association of Body Constitution with the Prognosis of IgA Nephropathy: A Long-Time Follow-Up of 203 Cases in China

Objective

This study investigated the association between body constitution (BC) and the prognosis of IgA nephropathy.

Methods

We analyzed 203 biopsy-diagnosed IgA nephropathy patients, who were followed up for (63.9±16.2) months. The participants' BC statuses were evaluated with the Constitution in Chinese Medicine Questionnaire; the relationships between clinical parameters and renal outcomes were analyzed by Cox regression.

Results

Patients were classified into chronic kidney disease stages with 43.4% in stage 1, 27.1% in stage 2, 26.1% in stage 3, 3.5% in stage 4, and none in stage 5. Qi-deficiency BC type was the most common BC type in IgA nephropathy patients. In univariate analysis, proteinuria of more than 1g/d, hypertension, renal impairment (estimated glomerular filtration rate <60 mL/min), hypoproteinemia, hyperuricemia, Yang-deficiency BC, and blood-stasis BC were associated with poor prognosis. Multivariate analysis identified that hypertension (hazard ratios (HR) 3.5, P=0.009), renal impairment (HR 5.8, P<0.001), Yang-deficiency BC (HR 2.3, P=0.041), and blood-stasis BC (HR 2.5, P=0.017) were independent predictors of unfavorable renal outcomes.

Conclusions

Most patients of IgA nephropathy were biopsied at an early stage. Yang-deficiency BC and blood-stasis BC at biopsy were most closely associated with the worse prognosis of IgA nephropathy along with hypertension and renal impairment.

Cohort Study of Repeated Measurements of Serum Urate and Risk of Incident Atrial Fibrillation

Background Current evidence on the association between serum urate and risk of atrial fibrillation ( AF ) is limited by cross-sectional designs and 1-time measurement of serum urate. The roles of serum urate, gout-related inflammation, and systemic inflammation in the etiology of AF are currently unknown. This gap is important, given that systemic inflammation is a recognized risk factor for AF . Methods and Results We conducted a prospective cohort study of 123 238 Chinese patients from 2006 to 2014. Serum urate concentrations were measured in 2006, 2008, 2010, and 2012. Incident AF cases were identified via biennial 12-lead ECG assessment. We used a Cox proportional hazards model to examine the sex-specific associations of cumulative average serum urate and changes in serum urate accounting for baseline level with risk of incident AF . We also assessed the joint associations of serum urate and high-sensitivity C-reactive protein levels. Comparing extreme categories, participants with the highest quintile of serum urate had 1.91-fold higher risk of AF (adjusted hazard ratio: 1.91; 95% CI, 1.32-2.76; P=0.001 for trend). Participants with both high serum urate and high-sensitivity C-reactive protein had 2.6-fold elevated risk of incident AF compared with those with normal levels of serum urate and high-sensitivity C-reactive protein (adjusted hazard ratio: 2.63; 95% CI, 1.63-4.23). Conclusions High serum urate levels and increases in serum urate over time were associated with increased risk of incident AF . Patients with high levels of both serum urate and high-sensitivity C-reactive protein had substantially higher risk of AF .

Significance of the combination of inter-limb blood pressure differences in the elderly: The Northern Shanghai Study

Whether the combination of inter-arm and inter-leg systolic blood pressure differences (BPDs) and ankle-brachial index is of clinical significance remains unclear. In this study, we aimed to investigate the association of the combination of inter-limb systolic BPDs with cardiovascular risk factors and hypertension-mediated organ damage (HMOD). A total of 2621 elderly subjects from the Northern Shanghai Study were divided into Group A, B, and C consisting of participants with 0, 1, and ≥2 abnormal inter-limb systolic BPDs, respectively. Comparisons of cardiovascular risk factors and parameters of cardiac, vascular, and renal damage between groups and logistic regression models were conducted. The proportions of subjects presenting 0, 1, and ≥2 abnormal inter-limb systolic BPDs were 60.9%, 25.1%, and 14.0%, respectively. Upward trends, from Group A, through Group B, to Group C, were observed for the level or prevalence of nearly all cardiovascular risk factors and HMOD (P for trend ≤0.007 for all). In multiple logistic regression, Group C showed significantly higher odds for carotid plaque (vs Group A: Odds ratio [OR] = 1.88, 95% confidence interval [CI] = 1.43-2.48; vs Group B: OR = 1.46, 95% CI = 1.08-1.97), arterial stiffness (vs Group A: OR = 1.26, 95% CI = 0.96-1.65; vs Group B: OR = 1.36, 95% CI = 1.01-1.83), and left ventricular hypertrophy (vs Group A: OR = 1.35, 95% CI = 1.04-1.76; vs Group B: OR = 1.25, 95% CI = 0.93-1.67), when compared with Group A and B. In conclusion, the combination of abnormal inter-limb systolic BPDs significantly associates with greater burden of cardiovascular risk factors and higher likelihood for HMOD, especially carotid plaque, arterial stiffness, and left ventricular hypertrophy.

APOL1 high-risk genotypes and renal transplantation

The discovery of apolipoprotein L1 (APOL1) gene variants and its association with kidney disease in African-Americans represent a significant breakthrough in understanding the genetic basis of ancestry-based differences in a public health problem. The role these variants play in renal transplantation is still incompletely understood. This article reviews the epidemiologic data and current reports of APOL1 variant pathogenesis in transplantation. We examine existing data on outcomes in APOL1 high-risk kidneys, high-risk APOL1 recipients, live donors with high-risk mutations and non-renal transplantation of high-risk APOL1 organs. We discuss the rapidly evolving role and potential pros and cons of APOL1 genotyping of donors and recipients in transplantation. Finally, we highlight the ongoing nationwide National Institutes of Health-sponsored "APOL1 Long-term Kidney Transplantation Outcomes (APOLLO)" study, which will quantify outcomes and "second hits" in pertinent to APOL1 high-risk variants in renal transplantation.

ASSOCIATIONS BETWEEN VITAMIN D AND MICROVASCULAR COMPLICATIONS IN MIDDLE-AGED AND ELDERLY DIABETIC PATIENTS

Objective: The objective of this cross-sectional study was to investigate the association of serum 25-hydroxyvitamin D (25[OH]D) levels with estimated glomerular filtration rate (eGFR), albumin/creatinine ratio (ACR), and the prevalence of diabetic retinopathy (DR) in Chinese diabetic adults. Methods: A total of 4,767 diabetic participants were enrolled from seven communities in Shanghai, China, in 2018. Participants underwent several examinations, which included the measurement of anthropometric parameters, blood pressure, glucose, lipid profiles, 25(OH)D, and ACR. DR was detected based on high-quality fundus photographs and remotely read by ophthalmologists. Results: Compared with the first 25(OH)D quartile, participants in the fourth quartile had a lower prevalence of high ACR (odds ratio [OR], 0.77; 95% confidence interval [CI], 0.61 to 0.96) (P for trend <.01). No association was found between 25(OH)D levels and eGFR. For DR, the OR (95% CI) for DR ranging from 0 to 4 in ordinal logistic regression associated with 25(OH)D was 0.62 (0.47 to 0.82) for the fourth 25(OH)D quartile (P for trend <.01) compared with the first quartile. These associations were all fully adjusted for confounding factors. Conclusion: Lower serum 25(OH)D concentration is significantly associated with increased ACR and higher prevalence of DR in middle-aged and elderly diabetic adults. However, the possibility of a causal relationship between 25(OH)D deficiency and diabetic microvascular complications remains to be demonstrated. Abbreviations: 25(OH)D = 25-hydroxyvitamin D; ACR = albumin/creatinine ratio; BMI = body mass index; CI = confidence interval; DKD = diabetic kidney disease; DR = diabetic retinopathy; eGFR = estimated glomerular filtration rate; HbA1c = glycated hemoglobin; HDL = high-density lipoprotein; LDL = low-density lipoprotein; OR = odds ratio; T2DM = type 2 diabetes mellitus.

Full age spectrum equation versus CKD-EPI and MDRD equations to estimate glomerular filtration rate in adults with obstructive nephropathy

Objective

To compare the full age spectrum (FAS) equation with the Modification of Diet in Renal Disease (MDRD) and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations in predicting glomerular filtration rate (GFR) in patients with obstructive nephropathy.

Methods

Adult patients with obstructive nephropathy who had undergone a GFR measurement using technetium-99m diethylenetriaminepentaacetic acid radioisotope renography were enrolled in the study. The measured GFR was taken as the reference value. Bias, precision and accuracy were compared between the three equations. Kappa test and the Bland–Altman method were used to evaluate the classification and the agreement. Receiver operating characteristic (ROC) curve analysis was used to describe the diagnostic accuracy of each equation.

Results

A total of 327 patients were enrolled. The P30 value for the FAS equation was 60.2% in the overall study cohort. The FAS equation had the highest diagnostic accuracy (ROC^AUC = 0.87, 95% confidence interval [CI] 0.84, 0.91) compared with the MDRD equation (ROC^AUC = 0.86, 95% CI 0.82, 0.89). The median bias of the FAS equation was significantly higher than that of the MDRD equation (8.7 versus 7.6 ml/min/1.73 m², respectively).

Conclusions

Despite the drawbacks associated with each equation, the FAS equation was probably closer to ideal to estimate GFR in patients with obstructive nephropathy.

Distinct Uric Acid Trajectories Are Associated With Different Risks of Incident Hypertension in Middle-Aged Adults

OBJECTIVES

To identify common uric acid (UA) trajectories in middle-aged adults and to examine their association with the risk of hypertension.

PATIENTS AND METHODS

This prospective cohort included 5758 participants who were aged between 30 and 60 years without hypertension on or before June 1, 2011. Latent mixture modeling was used to identify UA trajectories from June 1, 2005, through June 1, 2011, as the predictor. Incident hypertension from June 1, 2011, through June 1, 2017, was used as the outcome.

RESULTS

We detected 5 distinct trajectory groups of UA in both men and women: low-stable (for women, n=720 [24.6%]; for men, n=732 [25.9%]), low-increasing (for women, n=599 [20.4%]; for men, n=696 [24.6%]), moderate-increasing (for women, n=660 [22.5%]; for men, n=634 [22.4%]), high-decreasing (for women, n=314 [10.7%]; for men, n=227 [8.0%]), and high-stable (for women, n=638, 21.8 %; for men, n=538, 19.0%). We observed that 284 women developed hypertension during a median follow-up of 5.9 years (range, 0.8-6.2 years) and 674 men developed hypertension during a median follow-up of 5.9 years (range, 0.7-6.2 years). Compared with the low-stable group, the moderate-increasing group had the highest risk, with adjusted hazard ratios (HRs) of 2.48 (95% CI, 1.64-3.74) in women and 1.84 (95% CI, 1.43-2.35) in men, followed by the high-stable group, with adjusted HRs of 1.97 (95% CI, 1.29-3.01) in women and 1.45 (95% CI, 1.15-1.88) in men. Notably, the low-increasing group with UA in the normal range also exhibited an increased risk, with adjusted HRs of 1.83 (95% CI, 1.20-2.79) in women and 1.42 (95% CI, 1.10-1.83) in men. The high-decreasing group did not exhibit a substantially increased risk. These observed associations between UA trajectories and hypertension were independent of concurrent weight change.

CONCLUSION

Our results suggest that distinct trajectories of UA are differently associated with hypertension risk in middle-aged adults.

Carotid intima-media thickness, but not chronic kidney disease independently associates with noncardiac arterial vascular events in South Africa

AIM

Although chronic kidney disease (CKD) as determined from estimated glomerular filtration rate (eGFR) is recommended for risk prediction by current hypertension guidelines, the equations to derive eGFR may not perform well in black Africans. We compared whether across the adult lifespan, eGFR or CKD are as closely associated with noncardiac arterial vascular events, as carotid intima-media thickness (IMT), in Africa.

METHODS

In 1152 black South Africans [480 with noncardiac arterial events (294 with critical lower limb ischemia, 186 with stroke) of which 37% were premature] and 672 age, sex and ethnicity-matched controls from a randomly selected community sample, we assessed relations between eGFR, CKD or carotid IMT (B-mode ultrasound) and arterial events.

RESULTS

From 20 years until old age, with or without adjustments, IMT was increased in those with as compared with without events (P < 0.01 at each decade of age). However, at any decade of age across the adult lifespan neither creatinine concentrations, nor eGFR were altered in those with arterial events (P > 0.28). Although IMT was strongly and independently associated with the odds of an event [odds ratio per 1 SD (0.171 mm) effect = 2.19, confidence interval = 1.75-2.78, P < 0.0001], neither creatinine concentrations (P = 0.89), modification of diet in renal disease-derived (P = 0.07), nor Chronic Kidney Disease Epidemiology Collaboration-derived [odds ratio per 1 SD (22.5 ml/min per 1.73 m) effect = 1.06, confidence interval = 0.89-1.27, P = 0.51] eGFR were independently associated with the odds of an event. Although many with premature events had an increased IMT (63%), few with either premature events (8%) or with events at an older age (21%) had CKD and CKD had a poor performance (0.539 ± 0.011) and low sensitivity (16%) for event detection.

CONCLUSION

In black South Africans, despite carotid IMT strongly associating with noncardiac arterial vascular events (stroke and critical lower limb ischaemia) consistently across the adult lifespan, few with events have CKD and CKD fails to associate with events.

Burden, access and disparities in kidney disease: chronic kidney disease hotspots and progress one step at a time

The 2019 International Society of Nephrology World Kidney Day theme is Kidney Health for Everyone Everywhere. It focuses on the uneven burden of acute kidney injury and chronic kidney disease (CKD) in different communities, identifies disparities and challenges in access to care and calls for universal health coverage for prevention and early treatment of kidney disease. This topic is fully in line with the Clinical Kidney Journal (ckj) editorial strategy for improving worldwide kidney care without leaving any community behind. Indeed, the first PubMed-recorded use of the term CKD hotspot was in ckj, where it was defined as 'countries, region[s], communities or ethnicities with higher than average incidence of CKD'. This issue of ckj contains the World Kidney Day editorial as well as contributions that illustrate two concepts: the need to validate biochemical thresholds generated in developed countries in other populations, as exemplified by Kidney Disease: Improving Global Outcomes CKD-mineral and bone disorder parameters in an African population, and the fact that some disease associations characteristic of developing countries may be described initially in developed countries, as exemplified by the association of APOL1 variants with CKD or by minimal change disease secondary to malaria, but have to be validated locally.

Prognostic Comparison of the Estimations of Renal Function in Patients With Acute Heart Failure

BACKGROUND

The prognostic significance of the eGFR calculated by either the four-level Race Chronic Kidney Disease-Epidemiology Collaboration study equation (CKD-EPI4R) or the Chinese-modified Modification of Diet in Renal Disease equation (cMDRD) has not been compared in Asian populations with acute heart failure (AHF).Methods and Results:A total of 3,044 patients hospitalized for AHF were enrolled. The National Death Registry was linked to identify deaths within a 5-year follow-up. Net reclassification improvement (NRI) was calculated to compare the prognostic value of either eGFR equation. During a median follow-up of 23.3 months, 1,424 (47%) patients died. Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently predictive of death in the total study population (hazard ratio and 95% confidence intervals per 1-SD: 0.76, 0.71-0.81 and 0.74, 0.70-0.79, respectively), and in the subgroups of either reduced (HFrEF) or preserved (HFpEF) ejection fraction, after accounting for important confounders. With reference to eGFR_cMDRD, eGFR_CKD-EPI4Rmay improve the NRI by 2.0% (0.8-3.2%) for the prediction of death. The prognostic value of the CKD stages categorized by eGFR_CKD-EPI4Rsignificantly outperformed eGFR_cMDRDwith a categorical NRI of 9.5% (4.7-14.3%) in the total study population, 11.5% in HFrEF, and 8.3% in HFpEF.

CONCLUSIONS

Both eGFR_cMDRDand eGFR_CKD-EPI4Rwere independently associated with long-term survival in patients with AHF. However, the CKD stages derived from eGFR_CKD-EPI4Rimproved the risk stratification of death, compared with eGFR_cMDRD.

Neutrophil-to-lymphocyte ratio and incident end-stage renal disease in Chinese patients with chronic kidney disease: results from the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE)

BACKGROUND

Chronic kidney disease (CKD) leads to end-stage renal failure and cardiovascular events. An attribute to these progressions is abnormalities in inflammation, which can be evaluated using the neutrophil-to-lymphocyte ratio (NLR). We aimed to investigate the association of NLR with the progression of end stage of renal disease (ESRD), cardiovascular disease (CVD) and all-cause mortality in Chinese patients with stages 1-4 CKD.

METHODS

Patients with stages 1-4 CKD (18-74 years of age) were recruited at 39 centers in 28 cities across 22 provinces in China since 2011. A total of 938 patients with complete NLR and other relevant clinical variables were included in the current analysis. Cox regression analysis was used to estimate the association between NLR and the outcomes including ESRD, CVD events or all-cause mortality.

RESULTS

Baseline NLR was related to age, hypertension, serum triglycerides, total serum cholesterol, CVD history, urine albumin to creatinine ratio (ACR), chronic kidney disease-mineral and bone disorder (CKD-MBD), hyperlipidemia rate, diabetes, and estimated glomerular filtration rate (eGFR). The study duration was 4.55 years (IQR 3.52-5.28). Cox regression analysis revealed an association of NLR and the risk of ESRD only in patients with stage 4 CKD. We did not observe any significant associations between abnormal NLR and the risk of either CVD or all-cause mortality in CKD patients in general and CKD patients grouped according to the disease stages in particular.

CONCLUSION

Our results suggest that NLR is associated with the risk of ESRD in Chinese patients with stage 4 CKD. NLR can be used in risk assessment for ESRD among patients with advanced CKD; this application is appealing considering NLR being a routine test. 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 ).

Estimated Glomerular Filtration Rates Show Minor but Significant Differences Between the Single and Subgroup Creatinine-Based Chronic Kidney Disease Epidemiology Collaboration Equations

The creatinine-based Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation can be calculated according to race, sex, and creatinine concentration (subgroup equation) or in the form expressed by one equation (single equation). Minor differences in the constants used in the CKD-EPI equations (subgroup vs single equations) could result in a significant difference in the estimated glomerular filtration rate (eGFR). We evaluated the impact of this difference in 79,709 Korean patients. The eGFR was calculated as an integer using the single and subgroup CKD-EPI equations. The differences in eGFR and GFR categories between the equations were analyzed. eGFR was higher in the subgroup equation than the single equation by 1 mL/min/1.73 m² for 12,476 (27.4%) Korean females. The GFR category based on the subgroup equation was reclassified using the single equation for 352 (0.77%) females. Based on the results, the constant of the single equation was optimized. There was no difference in eGFR values between equations using a multiplier of 1.0213 instead of 1.018 for the "white or other" females constant in the single CKD-EPI equation. Clinicians should carefully apply the CKD-EPI equation because eGFR values may differ by 1 mL/min/1.73 m² depending on the manner of calculation. To minimize these differences, the constants of the single equation should be revised.

Serum Stem Cell Factor Level Predicts Decline in Kidney Function in Healthy Aging Adults

BACKGROUND AND OBJECTIVES

Stem cell factor (SCF), the ligand of the c-kit receptor, actively participates in the organ reconstruction and fibrosis associated with various diseases, including kidney disease. However, it remains unclear whether SCF plays a role in kidney aging.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

In the present study, we measured the serum SCF level, estimated glomerular filtration rate (eGFR), and other biological parameters in a Chinese Han group of 892 subjects, and explored the relationship between SCF level and renal function during aging; we sought to define novel biomarkers of kidney aging.

RESULTS

Multiple linear regression was used to select potential indicators of decline in renal function. Only age, SCF level, and 25% maximum expiratory flow (25% MEF) were significant predictors after redundancy analysis (|r| > 0.70 and P < 0.05). Multiple linear regression showed that the relationship among eGFR, SCF level, and age could be described as follows: eGFR = 154.486 - (0.846 × age) - (0.011 × SCF level).

CONCLUSIONS

We found no between-gender difference in the effect of SCF on kidney aging. In conclusion, the SCF level is an ideal biomarker of renal aging and may help to predict changes in eGFR during aging.

Bone Turnover Markers and Probable Advanced Nonalcoholic Fatty Liver Disease in Middle-Aged and Elderly Men and Postmenopausal Women With Type 2 Diabetes

Objective: Type 2 diabetic patients have a higher incidence of nonalcoholic steatohepatitis (NASH) and advanced stages of fibrosis, and nonalcoholic fatty liver disease (NAFLD) is associated with impaired bone health. We aimed to investigate whether bone turnover is associated with the probable presence of NASH and fibrosis. Methods: In total, 4,937 diabetic participants from Shanghai, China were enrolled in 2018. Subjects with NAFLD were categorized into simple NAFLD and probable NASH groups based on the presence of a metabolic syndrome. The NAFLD fibrosis score was used to identify patients with a higher likelihood of advanced fibrosis. Results: In postmenopausal women, large N-mid fragment of osteocalcin (N-MID osteocalcin) was negatively associated with probable NASH (P for trend < 0.001). β-C-terminal cross-linked telopeptides of type I collagen (β-CTX) and procollagen type I N-terminal propeptide (P1NP) were positively associated with the probable presence of significant fibrosis in postmenopausal women (P for trend 0.015 and <0.001). However, in men, N-MID osteocalcin and β-CTX were negatively associated with the probable presence of significant fibrosis (P for trend 0.029 and 0.027). Conclusions: Significant associations among N-MID osteocalcin, β-CTX and P1NP, and probable advanced NAFLD were observed. Further prospective and animal studies are warranted to understand the causal relationship and underlying mechanism.

Relationships of Chronic Kidney Disease and Thyroid Dysfunction in Non-Dialysis Patients: A Pilot Study

<b><i>Context:</i></b> Patients with chronic kidney disease (CKD) usually manifest with disorder of thyroid hormone; however, the correlation is unknown. <b><i>Objective:</i></b> The study was designed to explore the relationships between CKD and thyroid dysfunction. <b><i>Design, Setting, and Participants:</i></b> A total number of 905 non-dialysis participants were collected at Nanjing First Hospital from August 2009 to October 2012 according to the case records system. Patients were grouped via the estimated glomerular filtration rate (eGFR) according to the KDIGO guideline. Levels of thyroid hormone and biomarkers in different CKD groups were compared by ANOVA. Prevalence of different thyroid diseases was calculated by χ² test. <b><i>Results:</i></b> We found that FT3 or T3 became more prevalent with increasing eGFR with the lowest level in CKD5 (<i>p</i> <i>&#x3c;</i> 0.01). No significant differences were found between groups in FT4, T4, or TSH (<i>p</i> &#x3e; 0.05). Frequency of euthyroid sick syndrome (ESS) in CKD groups was high, especially in CKD stage 5 (69.1%, <i>p</i> &#x3c; 0.01). eGFR had positive correlation with T3 and FT3 (<i>r</i> = 0.239, <i>p</i> = 0.0001; <i>r</i> = 0.292, <i>p</i> = 0.0001). ESS had correlations with prealbumin, β2-microglobin, eGFR, and C-reactive protein (<i>r</i> = 0.095, <i>p</i> = 0.004; <i>r</i> = –0.12, <i>p</i> = 0.001; <i>r</i> = 0.091,<i> p</i> = 0.007; <i>r</i> = –0.096, <i>p</i> = 0.008; <i>r</i> = 0.154, <i>p</i> = 0.001). After adjustment for prealbumin, uric acid, HbA1c, age, gender, eGFR, and β2-microglobin, binary regression revealed that hemoglobin, C-reactive protein, and albumin were independent influence factors of ESS (<i>p</i> = 0.016, <i>r</i> = 1.014; <i>p</i> = 0.023, <i>r</i> = 1.007; <i>p</i> = 0.029, <i>r</i> = 0.996). <b><i>Conclusion:</i></b> CKD patients have a high morbidity of ESS, mainly low T3 syndrome. Anemia, inflammation, and malnutrition may contribute to ESS in CKD.

Novel glomerular filtration markers

Chronic kidney disease is currently assessed by estimated glomerular filtration rate, a mathematical construct based on creatinine or creatinine and cystatin concentration. Creatinine-based equations have improved with standardization efforts and the Modification of Diet in Renal Disease Study (MDRD) and CKD-Epidemiology Collaboration Study (CKD-EPI). Because the measurement of creatinine is subject to interference from non-GFR determinants, alternative markers have long been sought. These have included cystatin C and low molecular weight proteins like β2-microglobulin and beta trace protein. Tubular disease often occurs before glomerular filtration is impaired and investigators have investigated the excretion of other low molecular weight proteins such as Neutrophil Gelatinase-Associated Lipocalin (NGAL) and Kidney Injury Molecule-1 and N-acetyl-β-d-glucosaminidase. While preliminary, there is some evidence linking these analytes with GFR, disease stage and mortality. Although asymmetrical dimethyl arginine, an inhibitor of nitric oxide, has been shown to be associated with progression of renal disease, symmetric dimethyl arginine may be a better marker. Recent work has also explored the potential of microRNA (miRNA) analysis and metabolomics studies to further elucidate this complex pathophysiologic disease process. Investigators hope to improve our ability to detect CKD by the use of test panels, i.e., various marker combinations thereof. Unfortunately, most of these markers lack standardization unlike traditional measures that rely on creatinine and cystatin C measurement.

Prevalence and Disease Burden of Chronic Kidney Disease

Chronic kidney disease (CKD) has been recognized as a leading public health problem worldwide. The global estimated prevalence of CKD is 13.4% (11.7-15.1%), and patients with end-stage kidney disease (ESKD) needing renal replacement therapy is estimated between 4.902 and 7.083 million. Through its effect on cardiovascular risk and ESKD, CKD directly affects the global burden of morbidity and mortality worldwide. The global increase in this disease is mainly driven by the increase in the prevalence of diabetes mellitus, hypertension, obesity, and aging. But in some regions, other causes such as infection, herbal and environmental toxins are still common. The large number of deaths for poor access to renal replacement therapy in developing countries, and also large increase of patients with ESKD in future, will produce substantial financial burden for even the most wealthy countries. Cost-effectiveness of preventive strategies to reduce the disease burden should be evaluated in relation to the local economic development and resource. Strategies reducing the cardiovascular risk in CKD still need further evaluation in large trials especially including patients with advanced kidney disease or end-stage kidney disease.

A randomized multicenter study on ambulatory blood pressure and arterial stiffness in patients treated with valsartan/amlodipine or nifedipine GITS

In a pre-specified subgroup analysis of a 12-week randomized multicenter study, we investigated effects of valsartan/amlodipine 80/5 mg single-pill combination (n = 75) and nifedipine GITS 30 mg (n = 75) on ambulatory blood pressure (BP) and arterial stiffness assessed by brachial-ankle pulse wave velocity (PWV) in patients with uncontrolled hypertension. At week 12, the between-treatment mean differences in systolic/diastolic BP were smaller for 24-hour and daytime (-2.1/-1.7 and -2.0/-1.5 mm Hg, respectively, P ≥ 0.22) but greater (P < 0.01) for nighttime (-4.0/-2.8 mm Hg, P ≤ 0.09), especially in sustained uncontrolled hypertension (-5.0/-4.1 mm Hg, P ≤ 0.04) and non-dippers (-6.5/-3.7 mm Hg, P ≤ 0.07), in favor of valsartan/amlodipine. At week 12, PWV was significantly reduced from baseline by valsartan/amlodipine (n = 59, P < 0.0001) but not nifedipine (n = 59, P = 0.06). The changes in PWV were significantly associated with that in ambulatory systolic BP and pulse pressure in the nifedipine (P ≤ 0.0008) but not valsartan/amlodipine group (P ≥ 0.57), with a significant interaction (P ≤ 0.045). The valsartan/amlodipine combination was more efficacious than nifedipine GITS in lowering nighttime BP in sustained uncontrolled hypertension and non-dippers, and in lowering arterial stiffness independent of BP lowering.

Serum levels of tumor necrosis factor alpha in patients with IgA nephropathy are closely associated with disease severity

Background

Tumor necrosis factor alpha (TNF-α) is considered to play an important role in the pathogenesis in IgA nephropathy (IgAN). The correlations between serum TNF-α and disease severity in patients with IgAN remain controversial.

Methods

Concentrations of serum TNF-α of 147 patients with IgAN and 126 healthy subjects were measured by chemiluminescence immunoassay. Correlations with clinicopathological features of patients with IgAN were evaluated.

Results

Serum levels of TNF-α [9.20 (7.70–10.60) pg/mL vs. 6.04 (5.11–7.23) pg/mL, P < 0.0001] were higher in patients with IgAN than that in healthy subjects. Receiver operating characteristic curve analysis revealed that TNF-α had better discrimination between patients with IgAN and healthy controls than estimated glomerular filtration rate [TNF-α: (AUC, 0.87; 95% CI, 0.83–0.91; P < 0.0001) vs. estimated glomerular filtration rate: (AUC, 0.76; 95% CI, 0.71–0.82; P < 0.0001), P = 0.007]. Multivariate linear regression analyses showed that serum levels of TNF-α were positively correlated with 24-h urine protein excretion (r = 0.33, P = 0.04), urinary protein to serum creatinine ratio (r = 0.33, P = 0.03), serum creatinine (r = 0.46, P < 0.0001) and Cystatin C (r = 0.59, P < 0.0001) in IgAN and negatively correlated with estimated glomerular filtration rate (r = − 0.49, P < 0.0001) after adjustment for sex, systolic blood pressure and diastolic blood pressure. Patients with higher mesangial hypercellularity or tubular atrophy/interstitial fibrosis score according to Oxford classification showed higher serum levels of TNF-α.

Conclusions

Our data showed that serum levels of TNF-α detected by chemiluminescence immunoassay was a potential biomarker for evaluating the disease severity in IgAN.

Electronic supplementary material

The online version of this article (10.1186/s12882-018-1069-0) contains supplementary material, which is available to authorized users.

[Which biological parameters for volemic status estimation?]

INTRODUCTION

Estimation of volemic status can be useful in the diagnosis of some hydro-electrolytic disorders such as hyponatremia and dyskalemia. As a matter of fact, clinical examination and classical biological parameters are not discriminant enough. The aim of this study was to determine the biological parameters that are better correlated to volemic status.

METHOD

Volemic status was established using extracellular fluid volume, measured by apparent distribution of inuline, in non-edematous patients and without cardiac or hepatic insufficiency. Patients were split in three groups according to their extracellular fluid volume: hypovolemic, normovolemic, and hypervolemic. Clinical and biological parameters were compared between the three groups and were correlated to extracellular fluid volume.

RESULTS

Data of 91 explorations were collected. There were no difference between groups regarding clinical parameters, plasma proteins, and urinary sodium excretion. Parameters better correlated to extracellular fluid volume were fasting calcium/creatinine ratio (r=0.51; P<0.0001), fasting urinary pH (r=0.43; P<0.0001), and plasma uric acid (r=-0.39; P=0.002).

CONCLUSION

In addition to uric acid, already proposed as a biological marker to estimate volemic status, fasting calciuria and fasting urinary pH could also be useful.

Long-Term Exposure to Ambient Fine Particulate Matter and Chronic Kidney Disease: A Cohort Study

BACKGROUND

Chronic kidney disease (CKD) is a serious global public health challenge, but there is limited information on the connection between air pollution and risk of CKD.

OBJECTIVE

The aim of this study was to investigate the association between long-term exposure to particulate matter (PM) with an aerodynamic diameter of less than [Formula: see text] ([Formula: see text]) and the development of CKD in a large cohort.

METHODS

A total of 100,629 nonCKD Taiwanese residents age 20 y or above were included in this study between 2001 and 2014. Ambient [Formula: see text] concentration was estimated at each participant's address using a satellite-based spatiotemporal model. Incident CKD cases were identified by an estimated glomerular filtration rate (eGFR) of less than [Formula: see text]. We collected information on a wide range of potential confounders/modifiers during the medical examinations. Cox proportional hazard regression was applied to calculate hazard ratios (HRs).

RESULTS

During the follow-up, 4,046 incident CKD cases were identified, and the incidence rate was 6.24 per 1,000 person-years. In contrast with participants with the first quintile exposure of [Formula: see text], participants with the fourth and fifth quintiles exposure of [Formula: see text] had increased risk of CKD development, adjusting for age, sex, educational level, smoking, drinking, body mass index, systolic blood pressure, fasting glucose, total cholesterol, and self-reported heart disease or stroke, with an HR [95% confidence interval (CI)] of 1.11 (1.02, 1.22) and 1.15 (1.05, 1.26), respectively. A significant concentration-response trend was observed ([Formula: see text]). Every [Formula: see text] increment in the [Formula: see text] concentration was associated with a 6% higher risk of developing CKD (HR: 1.06, 95% CI: 1.02, 1.10). Sensitivity and stratified analyses yielded similar results.

CONCLUSIONS

Long-term exposure to ambient [Formula: see text] was associated with an increased risk of CKD development. Our findings reinforce the urgency to develop global strategies of air pollution reduction to prevent CKD. https://doi.org/10.1289/EHP3304.

A randomized intervention study to evaluate the effect of calcitriol therapy on the renin-angiotensin system in diabetes

Background:

Prior studies suggest that vitamin D therapy may decrease cardiovascular disease risk in type 2 diabetes (T2DM) by lowering renin-angiotensin system (RAS) activity. However, randomized human intervention studies to evaluate the effect of vitamin D receptor (VDR) agonists on RAS activity are lacking.

Objective:

The objective of this article is to investigate the effect of direct VDR activation with calcitriol on circulating RAS activity and vascular hemodynamics in T2DM.

Methods:

A randomized, double-blinded, and placebo-controlled study wherein 18 participants with well-controlled T2DM without chronic kidney disease (CKD) were administered calcitriol or placebo for three weeks was conducted. Outcome measures included plasma renin activity (PRA), serum and urinary aldosterone, mean arterial pressure (MAP) before and after an infusion of angiotensin II, and renal plasma flow (RPF) via para-aminohippurate clearance.

Results:

Despite an increase in 1,25(OH)₂D with calcitriol administration (45.4 to 61.8 pg/ml, p = 0.03) and no change with placebo, there were no significant differences in PRA, serum or urinary aldosterone, baseline and angiotensin II-stimulated MAP, or basal and angiotensin II-stimulated RPF between interventions.

Conclusion:

In this randomized and placebo-controlled study in participants with T2DM without CKD, calcitriol therapy to raise 1,25(OH)₂D levels, when compared with placebo, did not significantly change circulating RAS activity or vascular hemodynamics.

Estimating Renal Function in Drug Development: Time to Take the Fork in the Road

Renal function is the most commonly applied patient-specific quantitative variable used to determine drug doses. Measurement of renal function is not practical in most clinical settings; therefore, clinicians often rely on estimates when making dosing decisions. Similarly, renal function estimates are used to assign subjects in phase 1 pharmacokinetic studies, which inform dosing in late-phase clinical trials and ultimately the product label. The Cockcroft-Gault estimate of creatinine clearance has been the standard renal function metric; however, this paradigm is shifting toward the Modification of Diet in Renal Diseases (MDRD) estimate of the glomerular filtration rate (GFR). The proportion of approved new drug labels with dosing recommendations based on the MDRD equation was 16.7% in 2015, 70.0% in 2016, and 46.7% in 2017. Disharmonious recommendations from the United States Food and Drug Administration and the European Medicines Agency will continue to increase this heterogeneity in the assessment of renal function in drug development and negatively impact industry, health systems, and clinicians. In this review, we discuss the current regulatory guidance for the conduct of renal impairment pharmacokinetic studies and review the implications of this guidance across the medication use system with 3 recently approved antibiotics: ceftazidime/avibactam, delafloxacin, and meropenem/vaborbactam. Finally, we suggest measuring GFR in phase 1 studies and employing the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation to integrate data across clinical trials. This will help to harmonize CKD staging, population pharmacokinetic analyses, and dosing by estimated renal function.

Prevalence of atheromatous and non-atheromatous cardiovascular disease by age in chronic kidney disease

Background

Although chronic kidney disease (CKD) and age are major risk factors for cardiovascular disease (CVD), little is known about the relative proportions of atheromatous and non-atheromatous CVD by age in CKD patients.

Methods

We used baseline data from the French Chronic Kidney Disease-Renal Epidemiology and Information Network (CKD-REIN) cohort of 3033 patients (65% men) with CKD Stages 3–4 to study crude and adjusted associations between age, the estimated glomerular filtration rate (eGFR), atheromatous CVD (coronary artery disease, peripheral artery disease and stroke) and non-atheromatous CVD (heart failure, cardiac arrhythmia and valvular heart disease).

Results

Mean age was 66.8 and mean Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR was 32.9 mL/min/1.73 m2. In the &lt;65, (65–74), (75–84) and ≥85 year age groups, the prevalence was, respectively, 18.7, 35.5, 42.9 and 37.8% for atheromatous CVD, and 14.9, 28.4, 38.1 and 56.4% for non-atheromatous CVD. After adjusting for albuminuria, sex and CVD risk factors, the odds ratio (OR) [95% confidence interval (CI)] for (65–74), (75–84) and ≥85 age groups (compared with the &lt;65 group) was, respectively, 1.99 (1.61–2.46), 2.89 (2.30–3.62), 2.72 (1.77–4.18) for atheromatous CVD and 2.07 (1.66–2.58), 3.15 (2.50–3.97), 7.04 (4.67–10.61) for non-atheromatous CVD. Compared with patients with an eGFR ≥30 mL/min/1.73 m2, those with an eGFR &lt;30 mL/min/1.73 m2 had a higher OR for atheromatous CVD [1.21 (1.01–1.44)] and non-atheromatous CVD [1.16 (0.97–1.38)].

Conclusions

In this large cohort of CKD patients, both atheromatous and non-atheromatous CVD were highly prevalent and more frequent in older patients. In a given age group, the prevalence of atheromatous and non-atheromatous CVD was similar (except for a greater prevalence of non-atheromatous CVD after 85).

Sociodemographic associations with abnormal estimated glomerular filtration rate (eGFR) in a large Canadian city: a cross-sectional observation study

BACKGROUND

Chronic kidney disease (CKD) is often asymptomatic in its early stages but is indicated and is diagnosed with an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m2. Certain sociodemographic groups are known to be at risk for CKD, but it is unclear if there are strong associations between these at risk groups with abnormal eGFR test results in Canada. Using only secondary laboratory and Census data, geospatial variation and sociodemographic associations with abnormal eGFR result rate were investigated in Calgary, Alberta.

METHODS

Secondary laboratory data from all adult community patients who received an eGFR test result were collected from Calgary Laboratory Service's Laboratory Information System, which is the sole supplier of laboratory services for the large metropolitan city. Group-level sociodemographic variables were inferred by combining laboratory data with the 2011 Canadian Census data. Poisson regression and relative risk (RR) were used to calculate associations between sociodemographic variables with abnormal eGFR. Geographical distribution of abnormal eGFR result rates were analyzed by geospatial analysis using ArcGIS.

RESULTS

Of the 346,663 adult community patients who received an eGFR test result, 28,091 were abnormal (8.1%; eGFR < 60 ml/min/1.73m2). Geospatial analysis revealed distinct geographical variation in abnormal eGFR result rates in Calgary. Women (RR = 1.11, P < 0.0001), and the elderly (age ≥ 70 years; P < 0.0001) were significantly associated with an increased risk for CKD, while visible minority Chinese (RR = 0.73, P = 0.0011), South Asians (RR = 0.67, P < 0.0001) and those with a high median household income (RR = 0.88, P < 0.0001) had a significantly reduced risk for CKD.

CONCLUSIONS

Presented here are significant sociodemographic risk associations, and geospatial clustering of abnormal eGFR result rates in a large metropolitan Canadian city. Using solely publically available secondary laboratory and Census data, the results from this study aligns with known sociodemographic risk factors for CKD, as certain sociodemographic variables were at a higher risk for having an abnormal eGFR test result, while others were protective in this analysis.

Relationship between serum bilirubin levels s and the progression of renal function in patients with chronic kidney disease and hyperuricemia

It is known that inflammation and oxidative stress have strong influences on chronic kidney disease (CKD). As an antioxidant, bilirubin is currently under extensive scrutiny. However, there are disagreements with regard to the oxidative and antioxidative roles of serum uric acid (SUA). This study aimed to investigate the relationship between serum bilirubin and the progression of renal function in CKD patients with hyperuricemia (HUA). This retrospective longitudinal study included 427 CKD patients. The endpoint was renal replacement therapy or death. Patients were divided into the following two groups according to the SUA level: HUA group (SUA ≥ 420 μmol/L for men; SUA ≥ 360 μmol/L for women) and normal uric acid level (NUA) group. A Cox proportional hazards model was used to evaluate the risk factors for renal outcomes in the two patient groups. The median follow-up time was 36 months. In the Cox regression analysis, the risk of renal outcomes in patients with serum indirect bilirubin (IBIL) levels >4.55 μmol/L was 0.15 times the risk in patients with serum IBIL levels ≤4.55 μmol/L (hazard ratio = 0.15, p = .013). Our findings suggest that a high serum IBIL level might be a protective factor for the progression of renal function in CKD patients with HUA.

De novo aortopathy and cardiovascular outcomes in paediatric liver transplant recipients

With the increase in long-term survival of post-transplant children, there is a paradigm shift in the emphasis of post-transplant care. We describe de novo cardiovascular abnormalities, which occurred in otherwise asymptomatic paediatric liver transplant recipients, who received liver allografts between 1991 and 2014 at the National University Hospital, Singapore, detected during routine post-transplant monitoring. A total of 96 paediatric liver transplants were performed in 90 children. After transplant, 7/90 (7.8%) recipients were identified with new-onset aortopathy. Glycogen storage disease type I (42.9% versus 2.4%; p<0.001) and recipient Epstein-Barr virus seropositivity (85.7 versus 31.0%, p=0.004) were significant risk factors for aortopathy on univariate analysis. On multivariate analysis, only glycogen storage disease type I remained as the significant risk factor (odds ratio 51.3 [95% confidence intervals: 1.1-2498.1, p=0.047]). Liver transplant is a double-edged sword that reverses certain cardiopulmonary complications of end-stage liver disease but may induce de novo structural cardiac injury in the form of aortic dilation.

U6 can be used as a housekeeping gene for urinary sediment miRNA studies of IgA nephropathy

Recent studies have indicated that urinary sediment miRNAs not only are able to serve as non-invasive diagnostic biomarkers for IgA nephropathy (IgAN) but may also be closely related to several clinical and pathological indicators. However, the lack of a suitable internal reference miRNA has hampered research into urinary sediment miRNAs. To date, U6 has been used as a reference gene in urinary sediment miRNA studies mostly based on the results from studies using tissue samples and cell lines. In a total of 330 IgAN patients, 164 disease control patients and 130 normal control patients, there was no significant difference in U6 levels. We also compared the U6 levels in different types of primary glomerular disease groups (IgA nephropathy, membranous nephropathy, minimal change nephrosis and focal segmental glomerular sclerosis). The results confirmed that there was no significant difference in the expression of U6 in different primary glomerular disease groups. Moreover, treatment had no significant effect on the expression levels of U6 in IgA nephropathy. Therefore, U6 is an excellent housekeeping gene for urinary sediment miRNA studies of IgA nephropathy.

Prospective Comparison of Equations Based on Creatinine and Cystatin C for the Glomerular Filtration Rate Estimation in Chinese Renal Transplant Recipients

BACKGROUND

Currently, there is no dedicated equation to estimate glomerular filtration rate (GFR) for transplanted kidneys. This study aimed to compare the performance of serum creatinine (Scr)- and cystatin C (CysC)-based equations in Chinese renal transplant recipients.

METHODS

A total of 252 stable renal transplant recipients were enrolled in this study. The plasma clearance of ^99mTc-DTPA (rGFR) was used as a reference standard. The Scr, CysC, and rGFR of the patients were measured on the same day. The bias, precision, accuracy (percentage of estimates within 10%, 30%, and 50% of rGFR), and agreements of 8 Scr and 5 CysC eGFR equations were assessed. The factors affecting the accuracy were also evaluated.

RESULTS

Among the Scr-based equations, the Japanese Society of Nephrology-Chronic Kidney Disease Initiatives (JSN-CKDI) equation had the best overall performance with a bias of -6.2 mL/min/1.73 m², and 96.1% of its estimates were within 30% of the rGFR. For the CysC-based equations, the Filler equation had the best performance with a bias of -3.9 mL/min/1.73 m², and 93.7% of its estimates were within 30% of the rGFR. Overall, the CysC-based equations showed better performance than the Scr-based equations. In addition, significant differences were observed between bias and gender and between bias and rGFR value in some equations, whereas transplantation time and immunosuppressive regimens were not correlated with the bias.

CONCLUSION

The JSN-CKDI equation provides the best estimation of the GFR equations, and the CysC-based equations performed better than the Scr-based equations in this population.

Prevalence of CKD, Diabetes, and Hypertension in Rural Tanzania

INTRODUCTION

Chronic kidney disease (CKD), diabetes, and hypertension play a disproportionate role in the growing public health challenge posed by noncommunicable diseases (NCDs) in East Africa. The impact of these NCDs may pose the greatest challenge in rural areas with limited screening and treatment facilities, although precise prevalence estimates of these conditions in rural Tanzania are lacking.

METHODS

The prevalence of CKD, diabetes, and hypertension, were estimated from a probability sample of adults (n = 739) residing in 2 communities within Kisarawe, a rural district of Tanzania. Following consent, participants were studied in their homes. Random point-of-care (POC) measures of glycosylated hemoglobin and blood pressure, were obtained. Serum creatinine, drawn at the POC and measured at Muhimbili National University, was used to calculate estimated glomerular filtration rate with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation.

RESULTS

The median age was 35 years (interquartile range 25-45 years). Overall the pooled prevalence for CKD stages III, IV, and V was 12.4% (95% confidence interval [CI] = 10.2-14.8). Surprisingly, the prevalence of CKD stage V (3.0%; 95% CI = 2.1-4.4) was high among the youngest age group (18-36 years). The prevalence estimates for prehypertension and hypertension were 38.0% (95% CI = 34.6-41.5) and 19.9% (95% CI = 17.1-22.9), respectively. The prevalence estimates for prediabetes and diabetes were 25.7% (95% CI = 22.6-29.1) and 14.8% (95% CI = 12.4-17.6), respectively.

CONCLUSION

Although this pilot study had a relatively small sample size, the prevalence estimates for CKD, diabetes, and hypertension were higher than we expected based on previous estimates from Tanzania. CKD was not significantly associated with diabetes or hypertension, suggesting the possibility of an alternative causality.

Comparison of ankle-brachial index and upstroke time in association with target organ damage: the Northern Shanghai Study

A recent study indicated that upstroke time per cardiac cycle (UTCC) in lower extremities is equivalent to ankle-brachial index (ABI) in diagnosing peripheral arterial disease and in predicting cardiovascular mortality. In this study, we aimed to compare ABI and UTCC in relation to target organ damage. A cohort of 1841 elderly participants from the Northern Shanghai Study was studied. ABI and UTCC were measured using VP-1000 device. Target organ damage including left ventricular hypertrophy and diastolic dysfunction, carotid intima-media thickness and plaque, carotid-femoral pulse wave velocity (CF-PWV), and renal damage, were evaluated by standardized methods. In correlation analysis, ABI and UTCC both significantly correlated with CF-PWV, carotid plaque, and estimated glomerular filtration rate, but not with cardiac damage. Compared with ABI, UTCC showed stronger correlation with CF-PWV. When ABI and UTCC separately put into fully adjusted multivariate logistic regression models, both ABI (OR: 2.27; 95% CI: 1.63-3.17) and UTCC (OR: 1.63; 95% CI: 1.18-2.24) significantly associated with carotid plaque, but only UTCC significantly associated with increased CF-PWV (OR: 1.66; 95% CI: 1.15-2.42) and renal damage (OR: 1.63; 95% CI: 1.07-2.47). When ABI and UTCC both put into multivariate stepwise logistic regression models together with covariates, consistent results were observed. In ROC curve analysis, after adjusted for cofounding factors, UTCC showed slightly greater area under curve than ABI in detecting increased CF-PWV (area under curve: 0.79 vs. 0.78; P = .008); however, no difference was observed between UTCC and ABI in discriminating renal damage and carotid plaque. In conclusion, compared with ABI, UTCC showed significantly stronger association with vascular and renal damage in this elderly Chinese cohort.

Evaluation of the CKD-EPI creatinine based glomerular filtration rate estimating equation in Black African and Indian adults in KwaZulu-Natal, South Africa

BACKGROUND

The estimation of glomerular filtration rate (GFR) plays a vital role in assessment of the renal function. This study evaluated the performance of the CKD-EPI_creat and MDRD equations in the South African Kwa-Zulu Natal population.

OBJECTIVES

The objectives if the study were to compare the of CKD-EPI_creat and MDRD equations in the selected population to the measured GFR using Sodium Technetium-99 m-diethylene-triamine-pentaacetate clearance derived GFR.

METHOD

Records of adult patients with measured GFR performed at the Nuclear Medicine Department at Inkosi Albert Luthuli Central Hospital, Durban, South Africa from 1 April 2014 to 31 March 2016 were reviewed. eGFR for all included patients was calculated using the MDRD equation without African American correction factor and the CKD-EPI_creat equation with and without the African American correction factor for the Black African patients. Statistical comparison of the eGFR with measured GFR was performed with Bland Altman bias plots, Wilcoxon match pairs signed ranks test and accuracy within 10% and 30%.ROC curve analysis assessed the sensitivity and specificity at eGFR <90 and < 60 ml/min/1.73m².

RESULTS

After exclusion, 287 patients were included for analysis with sufficient numbers for only the Black African and Indian patients. None of the equations showed accuracy of eGFR within 30% of measured GFR for 90% of patients. In the Black African population, the CKD-EPI_creat equation without the correction factor performed best. 17% and 14.4% of the Black African participants would be reclassified with the CKD-EPI_creat equation without and with the African American correction factor respectively compared to mGFR at a cut-off of 60 mls/min/1.73m².

CONCLUSION

None of the evaluated equations attained the 2002 KDOQI benchmark of P₃₀ >90%. 11.1-17% of individuals would have been incorrectly classified using the CKD-EPI_creat equation.

Incidence and Progression of Chronic Kidney Disease in Black and White Individuals with Type 2 Diabetes

BACKGROUND AND OBJECTIVES

Type 2 diabetes and associated CKD disproportionately affect blacks. It is uncertain if racial disparities in type 2 diabetes-associated CKD are driven by biologic factors that influence propensity to CKD or by differences in type 2 diabetes care.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a post hoc analysis of 1937 black and 6372 white participants of the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial to examine associations of black race with change in eGFR and risks of developing microalbuminuria, macroalbuminuria, incident CKD (eGFR<60 ml/min per 1.73m2, ≥25% decrease from baseline eGFR, and eGFR slope <-1.6 ml/min per 1.73 m2 per year), and kidney failure or serum creatinine >3.3 mg/dl.

RESULTS

During a median follow-up that ranged between 4.4 and 4.7 years, 278 black participants (58 per 1000 person-years) and 981 white participants (55 per 1000 person-years) developed microalbuminuria, 122 black participants (16 per 1000 person-years) and 374 white participants (14 per 1000 person-years) developed macroalbuminuria, 111 black participants (21 per 1000 person-years) and 499 white participants (28 per 1000 person-years) developed incident CKD, and 59 black participants (seven per 1000 person-years) and 178 white participants (six per 1000 person-years) developed kidney failure or serum creatinine >3.3 mg/dl. Compared with white participants, black participants had lower risks of incident CKD (hazard ratio, 0.73; 95% confidence intervals, 0.57 to 0.92). There were no significant differences by race in eGFR decline or in risks of microalbuminuria, macroalbuminuria, and kidney failure or of serum creatinine >3.3 mg/dl.

CONCLUSIONS

Black participants enrolled in a randomized controlled trial had lower rates of incident CKD compared with white participants. Rates of eGFR decline, microalbuminuria, macroalbuminuria, and kidney failure did not vary by race.

A Low Fixed Tacrolimus Starting Dose Is Effective and Safe in Chinese Renal Transplantation Recipients

Background

We investigated whether a low fixed Tac starting dose regimen could lead to a better achievement of Tac target concentrations, as well as an effective immunosuppressive treatment, in Chinese kidney transplant recipients (KTRs).

Material/Methods

We collected whole-blood and serum samples from 189 KTRs and the Tac starting dose was 2, 2.5, or 3 mg/day. Information on Tac C₀, dose, body weight, body mass index (BMI), Scr, eGFR, and CYP3A5 genotypes were collected from a routine therapeutic drug monitoring database. The correlation between Tac C₀ and body weight (or BMI) was investigated by calculating the goodness of fit. Multivariable logistic regression was performed to estimate the independent associated factors.

Results

The patients with 3 mg per day of Tac had higher C₀ at day 7 compared to those with 2 or 2.5 mg. For patients receiving the same Tac starting dose, no significant difference was found in Tac C₀ at day 7 among different body weight or BMI groups. There was no significant difference in Scr or eGFR at 1 year after transplant, nor was there a significant difference in the rates of DGF or AR at post-transplant day 30 among different Tac starting dose groups or among the 3 Tac C₀ range groups. CYP3A5 genotype and Tac initial dose were independently associated with Tac C₀.

Conclusions

CYP3A5 genotype and Tac initial dose were independently associated with Tac C₀ in renal transplant recipients. Our results suggest that a low Tac target C₀ range (5–8 ng/ml) with a low fixed starting dose (3 mg/day) would be safe and effective among Chinese KTRs.

Uncertainty in measurement: A review of the procedures for determining uncertainty in measurement and its use in deriving the biological variation of the estimated glomerular filtration rate

Procedures for assessing the uncertainty in measurement and estimates of biological variation are currently available for many measurands capable of direct analytical measurement. However, not all measurands or quantity values determined in a medical laboratory are provided by direct analytical measurement. Estimated glomerular filtration rate (eGFR) is such a quantity value. In this situation, the result is calculated from other measurements through a functional relationship in which the output value (the calculated quantity value) is derived from one or more input quantities by applying a defined mathematical equation.

The aims of this review are: to summarise the principal methods for assessing uncertainty in measurement in complicated non-linear expressions; and to describe an approach for estimating the uncertainty in measurement and biological variation of the Chronic Kidney Disease Epidemiology Collaboration equations for eGFR. In practice, either the direct application of the propagation of uncertainty in measurement equation or a Monte Carlo simulation procedure using a readily available spreadsheet may be used to evaluate uncertainty in measurement or the propagation of biological variation.

If the only recognised “uncertainty” is the biological variation in the measured serum creatinine, the equation for the propagation of uncertainties in measurement for the eGFR simplifies to an expression in which the coefficient of variation of the eGFR (or the biological variation of the eGFR) is directly proportional to the coefficient of variation of the measured serum creatinine (or the biological variation of the serum creatinine).

Immunosuppressive and antiviral treatment of hepatitis C virus-associated glomerular disease: A long-term follow-up

BACKGROUND

The evidence in the medical literature on the treatment of hepatitis C virus-associated glomerular disease is extremely limited. The advent of nonconventional immunosuppressive agents and direct-acting antivirals promises high efficacy and safety.

AIMS

We conducted an open-label, single-arm clinical study to examine the efficacy and safety of a combined approach for hepatitis C virus-associated glomerular disease.

METHODS

In the first phase of the study, patients with hepatitis C virus-associated glomerular disease received interferon-based antiviral therapy and immunosuppressive agents; since 2013, interferon-free antiviral therapy was adopted and novel immunosuppressants (including B-cell depleting agents and mycophenolate mofetil) or immunomodulators (ribavirin) were choiced. Virological and clinical responses were evaluated over a long observation period (median follow-up of 60 weeks and 46.5 months after the end of treatment with interferon and direct-acting antiviral agents, respectively).

RESULTS

We enrolled 25 consecutive patients with hepatitis C virus-associated glomerular disease, 8 being liver transplant recipients for hepatitis C. A total of 13 patients received therapy with direct-acting antivirals and experienced sustained viral response (serum hepatitis C virus RNA <12 IU/mL, 12 weeks after treatment ended, sustained viral response12). The mean (±standard deviation) proteinuria decreased from 2.61 ± 1.01 at baseline to 1.71 ± 1.43 (g/day) at sustained viral response 48, p = 0.031; microscopic hematuria and serum cryoglobulins disappeared in six (50%) and seven (64%) patients, respectively, after sustained viral response by direct-acting antivirals. Adverse events occurred in 69% (9/13) of patients and were mild, with four cases of ribavirin-related anemia requiring blood transfusions (no drop-outs). After sustained viral response by direct-acting antivirals, immunosuppressive and immunomodulatory agents were initiated in clinical relapsers ( n = 2) and nonresponders ( n = 3) with some benefit. Among patients on interferon-based regimens ( n = 12), viral response (sustained viral response 24) and dropout rates were 58% (7/12) and 33% (4/12), respectively. After sustained viral response by interferon-based therapy, clinical relapsers ( n = 3) were successfully managed with immunosuppressive agents in two patients.

CONCLUSION

Treatment with direct-acting antivirals provides excellent rates of viral response and safety in patients with hepatitis C virus-related glomerular disease; viral response was frequently accompanied by clinical improvement. The absence of hepatitis C virus RNA from serum allowed immunosuppressive and immunomodulatory therapies with benefits for glomerular abnormalities and no concern on hepatitis C virus replication.

Hypertension Control in Adults With CKD in China: Baseline Results From the Chinese Cohort Study of Chronic Kidney Disease (C-STRIDE)

BACKGROUND

Hypertension contributes to increased morbidity and mortality in the chronic kidney disease (CKD) population. Studies on blood pressure control in CKD patients in China are limited. In this study, we aimed to describe the status of blood pressure control in Chinese CKD patients based on the first national prospective CKD cohort data.

METHODS

A subgroup of Chinese Cohort Study of Chronic Kidney Disease participants with hypertension at baseline was included in the present study. Uncontrolled blood pressure was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg. Defined daily doses (DDDs) are used as a standard measurement of drug utilization in this population. Factors associated with uncontrolled blood pressure were analyzed using multivariable logistic regression.

RESULTS

There were 2,251 hypertensive CKD subjects among 2,873 predialysis CKD participants. The awareness, treatment, and control rates of hypertension were 80.7%, 95.6%, and 57.1%, respectively. Factors independently associated with uncontrolled blood pressure were overweight, obesity, albuminuria, decreased estimated glomerular filtration rate (eGFR), and diabetes. Over 50% of study subjects were prescribed 2 or more antihypertensive medications and only 7% were prescribed diuretics. Uncontrolled hypertensive patients were prescribed less antihypertensive medication than controlled hypertensives (DDD 1.3 [1.0-2.3] vs. 2.0 [1.0-3.1], P < 0.001).

CONCLUSIONS

Hypertension control was suboptimal among hypertensive CKD patients in China, especially among those overweight or with obesity, albuminuria, lower eGFR, and diabetes. Patients with uncontrolled hypertension should undergo treatment regimen evaluation to select the appropriate dosage and type of antihypertensive medications.

Resistant and undertreated hypertension in patients with chronic kidney disease: data from the PATRIOTIC survey

BACKGROUND

Hypertension is prevalent in chronic kidney disease (CKD), but the control of hypertension is suboptimal. We reported the prevalence and characteristics of resistant and undertreated hypertension based on a nationwide survey aiming to improve blood pressure (BP) control.

METHODS

Resistant hypertension (RH) was defined as BP above the target (<140/90 mm Hg) despite the use of 3 antihypertensive drugs or achieving the target BP by using ≥4 antihypertensive drugs. Undertreated hypertension was defined as uncontrolled hypertension (unCH) using ≤2 drugs. We compared the characteristics and antihypertensive treatment among different groups (including RH and unCH using ≤2 drugs). Multivariable logistic regression was used to detect factors associated with unCH using ≤2 drugs and RH.

RESULTS

4,435 nondialysis CKD patients with hypertension were analyzed, and 36.9% of participants achieved controlled hypertension (CH) using ≤3 drugs, 11.1% met the criteria for RH, and 52% had unCH despite the use of ≤ 2 antihypertensive drugs. Participants with unCH using ≤ 2 drugs had low usage of renin-angiotensin system blockers (36.8%) and diuretics (5.5%), which was much lower than participants with CH using ≤3 drugs and RH (P< 0.05). After multivariable adjustment, obesity, advanced CKD stages, urinary protein level of ≥1.5 g/24 h, diabetes, and cardiovascular disease were associated with RH in CKD patients (P< 0.05).

CONCLUSION

Compared with RH, undertreated hypertension contributes more to the unCH in Chinese CKD patients. It is important to ensure adequate antihypertensive treatment, including choosing antihypertensive drugs, that guidelines recommended.

Clinicopathological Features to Predict Progression of IgA Nephropathy with Mild Proteinuria

BACKGROUND/AIMS

In the past, little attention has been paid to patients with IgA nephropathy (IgAN) who had minimal proteinuria upon the onset. The aim of this study was to analyze the clinicopathological features and the prognostic factors in patients with IgA nephropathy.

METHODS

Data of patients that had their first renal biopsy in our hospital and were diagnosed with primary IgAN with proteinuria <1 g/d from January 1995 to December 2014 were retrospectively examined. Clinical records of the clinicopathological features, renal function, and proteinuria were collected and investigated. The factors affecting the renal function and proteinuria were analyzed by Cox regression. The predictive efficiencies of clinical and pathological models were evaluated by Harrell concordance index (C-index).

RESULTS

A total of 506 patients with IgA nephropathy were included in this study. (1) Baseline proteinuria greater than 0.5 g/d was positively associated with Oxford M, S, and T lesions. eGFR less than 90 mL/min/1.73 m2 were positively associated with Oxford T. (2) In the follow-up with a median of 50 months, 82 patients (16.2%) achieved complete clinical remission (CCR), whereas 54 patients (10.6%) showed an increase in creatinine by more than 50% (not progressing to end-stage renal disease). The cumulative proportion of creatinine increased >50%, and the values obtained by life-table analysis in 10, 15, and 20 years were 15%, 21%, and 22%, respectively. Significant differences were found in baseline age, proteinuria, and Oxford T between the group of creatinine increase >50% and the CCR group. (4) Multivariate COX regression showed that baseline age and proteinuria > 0.5 g/d were independent risk factors of adverse outcome. C-index suggested that the clinical model was more effective than the pathological models in predicting endpoint events. (5) Effect of the mean value during the follow-up on adverse endpoint events: Multivariate COX regression found that the mean proteinuria during follow-up was an independent influencing factor for the increase of creatinine by more than 50%.

CONCLUSION

(1) Proteinuria > 0.5g/d and eGFR < 90 mL/min/1.73 m2 may predict more severe pathological changes; (2) With the increase in age and baseline proteinuria, the risks of adverse endpoint events would increase significantly; (3) Pathology could roughly predict the adverse endpoint events but is less efficient than the clinical indicators; (4) Data during follow-up suggested that the patients should regularly test their renal function and proactively control their proteinuria.