Modification of the CKD epidemiology collaboration (CKD-EPI) equation for Japanese: accuracy and use for population estimates

NT-proBNP and Risk of Dementia in a General Japanese Elderly Population: The Hisayama Study

Background Epidemiological evidence implies a link between heart disease and dementia. However, few prospective studies have assessed the association between serum NT-proBNP (N-terminal pro-B-type natriuretic peptide) levels and dementia. Methods and Results A total of 1635 community-dwelling Japanese elderly aged ≥60 years without dementia (57% women, mean age±SD 70.8±7.7 years) were followed up for 10 years. Serum NT-proBNP levels were divided into 4 categories (≤54, 55-124, 125-299, and ≥300 pg/mL). The hazard ratios were estimated using a Cox proportional hazards model. During the follow-up period, 377 subjects developed all-cause dementia, 247 Alzheimer disease, and 102 vascular dementia. The age- and sex-adjusted incidence of all-cause dementia was 31.5 per 1000 person-years and increased significantly with higher serum NT-proBNP levels, being 16.4, 32.0, 35.7, and 45.5, respectively (P for trend <0.01). Subjects with serum NT-proBNP levels of ≥300 pg/mL had a significantly higher risk of all-cause dementia (hazard ratio=2.46, 95% CI 1.63-3.71) than those with serum NT-proBNP levels of ≤54 pg/mL after adjusting for confounders. Similar risks were observed for Alzheimer disease and vascular dementia. Incorporation of the serum NT-proBNP level into a model with known risk factors for dementia significantly improved the predictive ability for incident dementia (c-statistics 0.780-0.787, P=0.02; net reclassification improvement 0.189, P=0.001; integrated discrimination improvement 0.011, P=0.003). Conclusions Higher serum NT-proBNP levels were significantly associated with an increased risk of dementia. Serum NT-proBNP could be a novel biomarker for predicting future risk of dementia in the general elderly population.

Circadian hemodynamic characteristics in hypertensive patients with primary aldosteronism

OBJECTIVE

The present study aimed to compare circadian hemodynamic characteristics in hypertensive patients with and without primary aldosteronism.

METHODS

Circadian hemodynamics, including 24-h brachial and central blood pressure (BP), SBP variability indices, central pulse wave velocity (PWV), augmentation index (AIx@75), cardiac index, and total vascular resistance (TVR), were evaluated using an oscillometric device, Mobil-O-Graph, in 60 patients with primary aldosteronism (63.4±13.3 years, 47% women) and 120 age-matched and sex-matched patients with essential hypertension.

RESULTS

Office SBP, PWV, AIx@75, and BP variability indices were similar between groups; however, 24-h brachial (124 ± 14 vs 130 ± 11 mmHg) as well as central (112 ± 12 vs 120 ± 10 mmHg) SBP was higher (both P < 0.01), and the difference between 24-h brachial and central SBP (11 ± 5 vs 9 ± 3 mmHg, P < 0.05), an index of pressure amplification, was smaller in primary aldosteronism than in essential hypertension. In both groups, cardiac index decreased from daytime to night-time (both P < 0.01), but this decrease was smaller in primary aldosteronism (P < 0.05). During daytime, TVR in primary aldosteronism was higher than that in essential hypertension (P < 0.05), and the significant increase of TVR from daytime to night-time was lost in primary aldosteronism. In a multivariate stepwise regression model, primary aldosteronism emerged as an independent predictor of 24-h central SBP as well as the difference between 24-h brachial and central SBP.

CONCLUSION

Our results demonstrated that circadian hemodynamics in primary aldosteronism patients are characterized by increased central SBP, smaller disparity between brachial and central SBP, and disturbed circadian hemodynamic variation.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation

BACKGROUND

Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

METHODS

We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m² at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort).

RESULTS

In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy.

CONCLUSIONS

This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

Association Between Circadian Hemodynamic Characteristics and Target Organ Damage in Patients With Essential Hypertension

BACKGROUND

This study investigated the association between circadian hemodynamic characteristics and asymptomatic hypertensive organ damage.

METHODS

Circadian hemodynamics, including 24-hour brachial and aortic systolic blood pressure (SBP), pulse wave velocity (PWV), augmentation index (AIx@75), cardiac index, and total vascular resistance (TVR), were evaluated using an oscillometric device, Mobil-O-Graph, in 284 essential hypertensive patients (67.8 ± 16.0 years, 54% female). Hypertensive target organ damage (TOD), namely carotid wall thickening, left ventricular hypertrophy, and albuminuria, was assessed in all patients.

RESULTS

Office SBP and 24-hour brachial and aortic SBP all increased with increasing number of organs involved (all P < 0.01 for trend). After multivariate logistic regression analysis, 24-hour brachial SBP (odds ratio [OR] = 1.04 for 1 mm Hg increase, P < 0.001) as well as aortic SBP (OR = 1.03 for 1 mm Hg increase, P < 0.05) maintained significance. Percent decrease during nighttime in brachial SBP, PWV, and TVR, but not cardiac index, showed a significant graded relationship with the number of organs involved. In a multivariate stepwise regression model, the nighttime values of brachial SBP, PWV, and TVR emerged as independent predictors of the presence of TOD.

CONCLUSION

In essential hypertension, 24-hour aortic SBP could be a marker of subclinical TOD, and further, the blunted nocturnal BP reduction in TOD patients might be mediated by disturbed circadian hemodynamic variations in aortic SBP, vascular resistance, and arterial stiffness.

Renal effects of a sodium-glucose cotransporter 2 inhibitor, tofogliflozin, in relation to sodium intake and glycaemic status

AIMS

Little is known about whether sodium intake is associated with the clinical effects of SGLT2 inhibitors (SGLT2is); however, SGLT2is may increase urinary sodium excretion. Thus, we investigated the impact of daily sodium intake on the estimated glomerular filtration rate (eGFR) via an SGLT2i, tofogliflozin (TOFO), in patients with type 2 diabetes (T2D).

METHODS

Individual-level data on 775 T2D patients in TOFO Phase 3 trials were analysed. Adjusted changes in variables during 52 weeks of TOFO therapy were compared according to basal daily salt intake (DSI), which was measured based on estimated daily urinary sodium excretion using the Tanaka formula. Multivariable analysis was used to investigate the impact of basal DSI on changes in eGFR at Weeks 4 and 52.

RESULTS

Sixty-six percent of participants were men; mean age, HbA1c, body mass index, eGFR_MDRD and median DSI were 58.5 years, 8.0%, 25.6 kg/m² , 83.9 mL/min/1.73 m² and 9.3 g/d, respectively. In all participants, eGFR_MDRD sharply dipped during Week 4, and gradually increased by Week 52, showing a significant increase overall from baseline to Week 52. Multivariable analysis showed that basal DSI and HbA1c levels were independently correlated with eGFR_MDRD changes at Weeks 4 and 52. Additionally, lower baseline HbA1c and DSI levels were significantly correlated with a greater increase in eGFR_MDRD at Week 52.

CONCLUSIONS

Dietary salt intake, in addition to glycaemic control, correlates with changed eGFR_MDRD via TOFO. Thus, an appropriate dietary approach to therapy should be considered before treatment of T2D patients with an SGLT2i.

Sex-specific and pleiotropic effects underlying kidney function identified from GWAS meta-analysis

Chronic kidney disease (CKD) is a growing health burden currently affecting 10–15% of adults worldwide. Estimated glomerular filtration rate (eGFR) as a marker of kidney function is commonly used to diagnose CKD. We analyze eGFR data from the Nord-Trøndelag Health Study and Michigan Genomics Initiative and perform a GWAS meta-analysis with public summary statistics, more than doubling the sample size of previous meta-analyses. We identify 147 loci (53 novel) associated with eGFR, including genes involved in transcriptional regulation, kidney development, cellular signaling, metabolism, and solute transport. Additionally, sex-stratified analysis identifies one locus with more significant effects in women than men. Using genetic risk scores constructed from these eGFR meta-analysis results, we show that associated variants are generally predictive of CKD with only modest improvements in detection compared with other known clinical risk factors. Collectively, these results yield additional insight into the genetic factors underlying kidney function and progression to CKD.

Estimated glomerular filtration rate (eGFR) is a measure of kidney function and used to characterize chronic kidney disease. Here, Graham et al. identify 53 novel loci for eGFR in a GWAS meta-analysis, a subset of which are associated with other common diseases, such as diabetes and hypertension, based on PheWAS.

Gut microbiome-derived phenyl sulfate contributes to albuminuria in diabetic kidney disease

Diabetic kidney disease is a major cause of renal failure that urgently necessitates a breakthrough in disease management. Here we show using untargeted metabolomics that levels of phenyl sulfate, a gut microbiota-derived metabolite, increase with the progression of diabetes in rats overexpressing human uremic toxin transporter SLCO4C1 in the kidney, and are decreased in rats with limited proteinuria. In experimental models of diabetes, phenyl sulfate administration induces albuminuria and podocyte damage. In a diabetic patient cohort, phenyl sulfate levels significantly correlate with basal and predicted 2-year progression of albuminuria in patients with microalbuminuria. Inhibition of tyrosine phenol-lyase, a bacterial enzyme responsible for the synthesis of phenol from dietary tyrosine before it is metabolized into phenyl sulfate in the liver, reduces albuminuria in diabetic mice. Together, our results suggest that phenyl sulfate contributes to albuminuria and could be used as a disease marker and future therapeutic target in diabetic kidney disease.

Diabetes is a major cause of kidney disease. Here Kikuchi et al. show that phenol sulfate, a gut microbiota-derived metabolite, is increased in diabetic kidney disease and contributes to the pathology by promoting kidney injury, suggesting phenyl sulfate could be used a marker and therapeutic target for the treatment of diabetic kidney disease.

Involvement of Arterial Stiffness and Inflammation in Hyperuricemia-Related Development of Hypertension

This study analyzed repeated measurement data to clarify the longitudinal associations between hyperuricemia and the risk factors for the development of hypertension (ie, increased arterial stiffness, renal dysfunction, and inflammation), and then examined whether these risk factors show longitudinal associations with the development of hypertension. In 3274 Japanese men without hypertension, the brachial-ankle pulse wave velocity, blood pressure, estimated glomerular filtration rate, and serum uric acid and CRP (C-reactive protein) levels were measured annually over an 8-year period. Of these, 474 subjects developed hypertension by the end of the study period. Mixed model linear regression analysis revealed a significant longitudinal association of hyperuricemia with increase of the brachial-ankle pulse wave velocity (estimate=5.50, P=0.04), decrease of the estimated glomerular filtration rate (estimate=-2.02, P<0.01), and elevation of the CRP (estimate=0.08×10^-1, P=0.02). Hyperuricemia at the study baseline was associated with a significant odds ratio for the development of hypertension by the end of the study period. After adjustments for covariates, the brachial-ankle pulse wave velocity (estimate=0.51×10^-2, P<0.01) and CRP (estimate=1.91, P=0.03), but not estimated glomerular filtration rate, were found to show independent longitudinal associations with the new onset of hypertension. In Japanese men without hypertension, hyperuricemia may have a longitudinal association with the development of hypertension, and increased arterials stiffness and inflammation may be involved in the risk of development of hypertension associated with hyperuricemia.

Higher serum uric acid level is inversely associated with renal function assessed by cystatin C in a Japanese general population without chronic kidney disease: the KOBE study

Background

Although several epidemiological studies have suggested that high serum uric acid (SUA) levels are related to a decline in kidney function, only a few studies have investigated using cystatin C to calculate estimated glomerular filtration rate (eGFR). We aimed to clarify the relationship between SUA levels and kidney function assessed by cystatin C in a Japanese general community population without chronic kidney disease (CKD).

Methods

We conducted a community-based cross-sectional study that included 1086 healthy participants, aged 40–74 years, without CKD and not undergoing treatment of hyperuricemia, who had participated in the baseline survey of the Kobe Orthopedic and Biomedical Epidemiological (KOBE) study. The preconditions for participation in this study were no past histories of cardiovascular disease or cancer, and not undergoing treatment for diabetes, hypertension, or dyslipidemia. We classified the participants into quartiles stratified by sex according to their SUA level and then examined the relationship with eGFR. The odds ratios for having a low eGFR, defined as the lowest quartile of eGFR (i.e., ≤78.4 mL/min/1. 73m²) was estimated according to SUA quartiles (men, Q1 ≤ 5.0, Q2 5.1–5.9, Q3 6.0–6.6, and Q4 ≥ 6.7; women, Q1 ≤ 3.8, Q2 3.9–4.3, Q3 4.4–4.9, and Q4 ≥ 5.0 mg/dL) after adjustment for age, body mass index, systolic blood pressure, HbA1c, high and low density lipoprotein cholesterol, and smoking and drinking habits. The adjusted mean of each quartile was also calculated.

Results

Multivariable-adjusted means of eGFR showed a graded decrease in higher SUA quartiles (men, Q1 90.5, Q2 88.0, Q3 83.5, and Q4 82.0; women, Q1 95.7, Q2 91.3, Q3 89.2, and Q4 86.7). In addition, the multivariable-adjusted odds ratios for having a lower eGFR (95% confidence interval) for each SUA quartile compared with Q1 was Q2 2.29 (0.98, 5.35), Q3 4.94 (2.04, 11.97), and Q4 8.01 (3.20, 20.04) for men, and was Q2 2.20 (1.12, 4.32), Q3 2.68 (1.39, 5.20), and Q4 4.96 (2.62, 9.41) for women.

Conclusions

There was a graded inverse relationship between mild elevations in SUA levels and eGFR assessed by cystatin C in an apparently healthy Japanese population without CKD. This association was similar in both men and women.

Serum Uric Acid to Creatinine Ratio Independently Predicts Incident Metabolic Syndrome Among Community-Dwelling Persons

BACKGROUND

Metabolic syndrome (MetS) is related to the increased risk of major cardiovascular disease. The link between high serum uric acid (SUA) and creatinine (Cr) levels is causally related to MetS and its components. However, whether renal function-normalized SUA [i.e., SUA to Cr ratio (SUA/Cr)] predicts incident MetS and its components remains inconclusive.

MATERIALS AND METHODS

We conducted a prospective cohort study designed as part of the Nomura study. The subjects comprised 447 men ages 68 ± 10 years and 625 women ages 68 ± 9 years from a rural village, and 155 (34.7%) men and 310 women (49.6%) had MetS at baseline. We found participants who underwent a similar examination 3 years later and analyzed the relationship between baseline SUA/Cr and incident MetS defined according to the modified criteria of the National Cholesterol Education Program-Adult Treatment Panel III (NCEP ATP III).

RESULTS

One hundred forty-nine (33.3%) men and 286 (45.8%) women had MetS after a 3-year follow-up. Multiple linear regression analysis was performed to evaluate the contribution of possible confounding factors for MetS. In women only, baseline SUA/Cr, as well as baseline number of MetS and age, was significantly and independently associated with the number of MetS components at follow-up. The multivariable-adjusted odds ratios (95% confidence interval) for incident MetS across three quartiles of baseline SUA/Cr (1st-2nd, 3rd, and 4th) were 1.00, 1.62 (0.97-2.69), and 2.07 (1.20-3.56), respectively. Furthermore, when subjects were stratified by age, estimated glomerular filtration rate (eGFR), and presence of baseline MetS, baseline SUA/Cr was also a significant and independent determinant for incident MetS in women with age ≥60 years, eGFR ≥70 mL/min/1.73 m², and presence of baseline MetS.

CONCLUSIONS

Baseline SUA/Cr was significantly associated with incident MetS among community-dwelling women.

Trans-ethnic kidney function association study reveals putative causal genes and effects on kidney-specific disease aetiologies

Chronic kidney disease (CKD) affects ~10% of the global population, with considerable ethnic differences in prevalence and aetiology. We assemble genome-wide association studies of estimated glomerular filtration rate (eGFR), a measure of kidney function that defines CKD, in 312,468 individuals of diverse ancestry. We identify 127 distinct association signals with homogeneous effects on eGFR across ancestries and enrichment in genomic annotations including kidney-specific histone modifications. Fine-mapping reveals 40 high-confidence variants driving eGFR associations and highlights putative causal genes with cell-type specific expression in glomerulus, and in proximal and distal nephron. Mendelian randomisation supports causal effects of eGFR on overall and cause-specific CKD, kidney stone formation, diastolic blood pressure and hypertension. These results define novel molecular mechanisms and putative causal genes for eGFR, offering insight into clinical outcomes and routes to CKD treatment development.

Estimated glomerular filtration rate (eGFR) is a measure of kidney function used to define chronic kidney disease. Here, Morris et al. perform trans-ethnic genome-wide meta-analyses for eGFR in 312,468 individuals and identify novel loci and downstream putative causal genes.

Association of neutrophil-to-lymphocyte ratio with early renal dysfunction and albuminuria among diabetic patients

PURPOSE

Neutrophil-to-lymphocyte ratio (NLR) was widely studied as a prognostic marker in various medical and surgical specialties, but its significance in diabetic kidney disease is not yet established.

METHODS

The subjects comprised 199 men aged 73 ± 11 (mean ± standard deviation) years and 187 women aged 77 ± 10 years from a rural hospital. We examined the relationship between NLR calculated by analyzing differential leukocyte count in complete blood picture and renal function evaluated by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study Group equation and urinary albumin excretion (UAE).

RESULTS

NLR was negatively related to eGFR and positively related to UAE. Multiple linear regression analysis using eGFR and UAE as an objective variables, adjusted for confounding factors as explanatory variables showed that NLR (β = - 0.101, p = 0.009) as well as age, body mass index, serum uric acid, and presence of uric acid lowing medication were significantly and independently associated with eGFR, and NLR (β = 0.113, p = 0.031) as well as prevalence of cardiovascular disease, systolic blood pressure, presence of antihypertensive medication, presence of antilipidemic medication, and eGFR were significantly and independently associated with UAE. The multivariate-adjusted odds ratios (95% confidence interval) of NLR for stage 3a (eGFR < 60 mL/min/1.73 m²), stage 3b (eGFR < 45 mL/min/1.73 m²), and microalbuminuria (UAE ≥ 30 mg/g Cr) were 1.90 (1.02-3.56) and 2.99 (1.28-6.98), and 1.77 (1.04-3.01), respectively. Next, to examine the consistency of the observed association between NLR and eGFR, we performed subgroup analyses. There was a significant interaction (p = 0.006) only between the two groups regarding antihypertensive medication (absence: β = - 0.272, p < 0.001 and presence: β = - 0.029, p = 0.564).

CONCLUSIONS

Our data suggested that NLR might be important as a potential factor for evaluating patients with a higher degree of albuminuria among diabetic outpatients.

Factors involved in phenoconversion of CYP3A using 4β-hydroxycholesterol in stable kidney transplant recipients

BACKGROUND

Phenoconversion is a phenomenon whereby some genotypic extensive metabolizers transiently exhibit drug metabolizing enzyme activity at similar level as that of poor metabolizers. Renal failure is known to decrease CYP3A activity in humans. Indoxyl sulfate, parathyroid hormone (PTH), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α) have been reported to cause CYP3A downregulation in renal failure. We measured plasma concentrations of the above compounds in stable kidney transplant recipients, and evaluated their relations with phenoconversion of CYP3A evaluated by plasma concentration of 4β-hydroxycholesterol, a biomarker of CYP3A activity. Phenoconversion was defined as a genotypic extensive/intermediate metabolizer exhibiting CYP3A activity below the cutoff value that discriminates extensive/intermediate from poor metabolizers.

METHODS

Sixty-three Japanese kidney transplant recipients who underwent transplantation more than 180 days prior to the study were included. Morning blood samples were collected, and CYP3A5 polymorphism as well as plasma concentrations of 4β-hydroxycholesterol, indoxyl sulfate, intact-PTH, IL-6 and TNF-α were determined.

RESULTS

Significantly higher plasma 4β-hydroxycholesterol concentration was observed in recipients with CYP3A5*1 allele (n = 23) compared to those without the allele (n = 40), and the cut-off value was 40.0 ng/mL. Ten recipients with CYP3A5*1 allele exhibited CYP3A activity below 40.0 ng/mL (phenoconversion). Only plasma indoxyl sulfate concentration was significantly higher in recipients with CYP3A phenoconversion compared to those without phenoconversion.

CONCLUSIONS

These findings suggest that higher plasma indoxyl sulfate concentration may be involved in CYP3A phenoconversion. Dose adjustment of drugs metabolized by CYP3A may be needed in patients with CYP3A5*1 allele and high blood indoxyl sulfate.

Glomerular basement membrane duplication is a predictor of the prognosis of diabetic nephropathy in patients with type 2 diabetes

BACKGROUND

Several clinical parameters and pathological findings are known to be predictors of the deterioration of diabetic nephropathy (DN). Glomerular basement membrane duplication (GBM-DP) is a pathological feature representing endothelial injury, which is commonly observed in DN. In the present study, we investigated the association between GBM-DP and the renal prognosis in DN.

METHODS

The study enrolled 80 patients with renal biopsy-proven DN who were managed at Chiba-East Hospital from 2005 to 2012. We confirmed the pathological findings according to the Renal Pathology Society classifications, and we further evaluated the GBM-DP, which was defined as double contours of the GBM that expanded more than 10% of capillary loops in the most affected nonsclerotic glomerulus. We used Cox regression models to estimate hazard ratios (HRs) for end-stage renal disease (ESRD), with adjustment for age, sex, systolic blood pressure, HbA1c, estimated glomerular filtration rate (eGFR), and urinary protein excretion (UP) at baseline.

RESULTS

Of the 80 patients, 56 were male (70.0%) and the mean age was 59.1 years. The median eGFR and UP were 42 ml/min/1.73 m² (IQR 30, 59) and 3.1 g/gCr (IQR 1.2, 5.2). Twenty-seven patients progressed to ESRD and one patient died during the median observational period of 2.9 years (IQR 1.5, 4.3). The multivariable analyses showed that GBM-DP was significantly associated with ESRD (HR 3.18 [95% confidence interval (CI): 1.02-9.87], p = 0.045).

CONCLUSION

We newly identified GBM-DP as a strong prognostic predictor in DN patients. Further study is needed to clarify the pathogenic mechanism of GBM-DP in DN.

Chronological renal resistive index increases related to atherosclerotic factors, and effect of renin-angiotensin system inhibitors

BACKGROUND

Renal resistive index (RI) calculated using renal Doppler ultrasonography (RDU) has recently been considered a clinically important indicator of renal outcome, survival, and systemic arteriosclerotic disorders. However, the cause of RI elevation remains unclear. The present study was an effort to first, identify the factors related to RI elevation, and second, understand the effect of renin-angiotensin system inhibitors (RAS-Is) on renal RI elevation.

METHODS

We carried out this single-center case-control study among 100 CKD patients, recruited from outpatients who underwent RDU more than twice, at least a year apart. The rate of renal RI change per year (dRIpy) was chosen as the dependent variable: [(last examined renal RI-initial examined renal RI)/(initial examined renal RI × period of observation) × 100 (%/year)]. We examined the association between dRIpy and other clinical and biological data.

RESULTS

Among 100 CKD patients, the average serum creatinine and eGFR were 1.76 ± 0.84 mg/dL and 37.0 ± 18.2 ml/min/1.73 m², respectively. The average dRIpy in all patients was 1.8 ± 1.4%/year. The linear multiple regression demonstrated that dRIpy was positively associated with the presence of diabetes mellitus (DM) and high low-density lipoprotein cholesterol (LDL) levels, and negatively with eGFR and RAS-I use.

CONCLUSIONS

This study demonstrated that the elevation of RI was related to DM, eGFR, high LDL, and the use of RAS-Is. In particular, RAS-Is could contribute towards suppressing the elevation of RI in CKD patients and towards preventing the development of renal failure in CKD patients.

Identification of Novel Urinary Biomarkers for Predicting Renal Prognosis in Patients With Type 2 Diabetes by Glycan Profiling in a Multicenter Prospective Cohort Study: U-CARE Study 1

OBJECTIVE

Because quantifying glycans with complex structures is technically challenging, little is known about the association of glycosylation profiles with the renal prognosis in diabetic kidney disease (DKD).

RESEARCH DESIGN AND METHODS

In 675 patients with type 2 diabetes, we assessed the baseline urinary glycan signals binding to 45 lectins with different specificities. The end point was a decrease of estimated glomerular filtration rate (eGFR) by ≥30% from baseline or dialysis for end-stage renal disease.

RESULTS

During a median follow-up of 4.0 years, 63 patients reached the end point. Cox proportional hazards analysis revealed that urinary levels of glycans binding to six lectins were significantly associated with the outcome after adjustment for known indicators of DKD, although these urinary glycans, except that for DBA, were highly correlated with baseline albuminuria and eGFR. Hazard ratios for these lectins were (+1 SD for the glycan index) as follows: SNA (recognizing glycan Siaα2-6Gal/GalNAc), 1.42 (95% CI 1.14-1.76); RCA120 (Galβ4GlcNAc), 1.28 (1.01-1.64); DBA (GalNAcα3GalNAc), 0.80 (0.64-0.997); ABA (Galβ3GalNAc), 1.29 (1.02-1.64); Jacalin (Galβ3GalNAc), 1.30 (1.02-1.67); and ACA (Galβ3GalNAc), 1.32 (1.04-1.67). Adding these glycan indexes to a model containing known indicators of progression improved prediction of the outcome (net reclassification improvement increased by 0.51 [0.22-0.80], relative integrated discrimination improvement increased by 0.18 [0.01-0.35], and the Akaike information criterion decreased from 296 to 287).

CONCLUSIONS

The urinary glycan profile identified in this study may be useful for predicting renal prognosis in patients with type 2 diabetes. Additional investigation of glycosylation changes and urinary glycan excretion in DKD is needed.

Baseline and changes in serum uric acid independently predict 11-year incidence of metabolic syndrome among community-dwelling women

INTRODUCTION

Metabolic syndrome (MetS) is associated with an increased risk of major cardiovascular events. In women, increased serum uric acid (SUA) levels are associated with MetS and its components. However, whether baseline and changes in SUA predict incidence of MetS and its components remains unclear.

METHODS

The subjects comprised 407 women aged 71 ± 8 years from a rural village. We have identified participants who underwent a similar examination 11 years ago, and examined the relationship between baseline and changes in SUA, and MetS based on the modified criteria of the National Cholesterol Education Program's Adult Treatment Panel (NCEP-ATP) III report.

RESULTS

Of these subjects, 83 (20.4%) women at baseline and 190 (46.7%) women at follow-up had MetS. Multiple linear regression analysis was performed to evaluate the contribution of each confounding factor for MetS; both baseline and changes in SUA as well as history of cardiovascular disease, low-density lipoprotein cholesterol, and estimated glomerular filtration ratio (eGFR) were independently and significantly associated with the number of MetS components during an 11-year follow-up. The adjusted odds ratios (ORs) (95% confidence interval) for incident MetS across tertiles of baseline SUA and changes in SUA were 1.00, 1.47 (0.82-2.65), and 3.11 (1.66-5.83), and 1.00, 1.88 (1.03-3.40), and 2.49 (1.38-4.47), respectively. In addition, the combined effect between increased baseline and changes in SUA was also a significant and independent determinant for the accumulation of MetS components (F = 20.29, p < 0.001). The ORs for incident MetS were significant only in subjects with age ≥ 55 years, decline in eGFR, and no baseline MetS.

CONCLUSIONS

These results suggested that combined assessment of baseline and changes in SUA levels provides increased information for incident MetS, independent of other confounding factors in community-dwelling women.

Prognostic Value of Electrocardiographic Left Ventricular Hypertrophy on Cardiovascular Risk in a Non-Hypertensive Community-Based Population

BACKGROUND

The appearance of left ventricular hypertrophy on 12-lead electrocardiography (ECG-LVH) has been clarified to be associated with the risk of incidence of cardiovascular events (CVEs) in hypertensive individuals and the general population, but not enough in non-hypertensive individuals.

METHODS

A total of 4,927 non-hypertensive individuals ≥40 years of age who were free of CVE in the general population were followed for the incidence of CVE. ECG-LVH was defined according to criteria of the Sokolow-Lyon (SL) voltage, Cornell voltage (CV), or Cornell voltage product (CP).

RESULTS

During the average 9.8 ± 2.0 years of follow-up, 267 individuals (5.4%) had their first CVE. The hazard ratio (HR) for the incidence of CVE after full adjustment by potential confounders significantly increased in the individuals with ECG-LVH by any criteria of the SL voltage, CV, and CP (HR = 1.77, P < 0.001) compared to those with no ECG-LVH. This association was also significant in individuals without any of obesity, dyslipidemia, and diabetes mellitus or those with systolic blood pressure (BP) <120 mm Hg and diastolic BP <80 mm Hg. Furthermore, ECG-LVH by each criteria provided the reclassification improvement for the CVE risk prediction model by the Framingham 10-year risk score (the net reclassification improvement = 0.17-0.22, each P value < 0.010).

CONCLUSIONS

In the absence of hypertension, ECG-LVH parameters are associated with the increased risk of developed CVEs independent of the established risk factors and provide the additional prognostic value in an assessment of the CVE risk using the traditional risk factors.

Gender differences in the relationships between chronic kidney disease, asymmetric dimethylarginine, and sleep quality: The HEIJO-KYO cohort

The association between chronic kidney disease (CKD), serum levels of asymmetric dimethylarginine (ADMA), and sleep quality has not been studied in large populations. In this cross-sectional study of 1115 elderly individuals (mean age, 71.9 years), we measured serum levels of ADMA, and objective and subjective sleep quality using actigraphy and a standardized self-reported questionnaire, respectively. Multivariable analysis adjusted for potential confounders revealed that in females, compared with the non-CKD/low-ADMA group (n=312), sleep efficiency was significantly lower in the CKD/high-ADMA group (n=52) by 3.5% for objective sleep quality [95% confidence interval (CI), 1.1-5.9] and by 4.2% (95% CI, 0.3-8.0) for subjective sleep quality but not in the non-CKD/high-ADMA (n=179) and CKD/low-ADMA (n=36) groups. In males, no significant associations between CKD, ADMA levels, and sleep quality were observed. Wake time after sleep onset was significantly longer by 11.3 min (95% CI, 3.0-19.6) for objective sleep quality and by 25.9 min (95% CI, 4.9-46.9) for subjective sleep quality in the CKD/high-ADMA group than in the non-CKD/low-ADMA group in females but not in males. Mediation analysis revealed a significant effect of serum ADMA levels on the association between renal function and parameters of sleep quality among females. In conclusions, both objective and subjective sleep quality were poorer in elderly females with CKD/high-ADMA than in those with non-CKD/low-ADMA, but not in males. Association between CKD and sleep disturbances might be mediated by ADMA levels.

Optimal equation for estimation of glomerular filtration rate in autosomal dominant polycystic kidney disease: influence of tolvaptan

BACKGROUND

The reliability of various equations for estimating the GFR in ADPKD patients and the influence of tolvaptan on the resulting estimates have not been examined when GFR is calculated on the basis of inulin clearance.

METHODS

We obtained baseline and on-tolvaptan measured GFRs (mGFRs), calculated on the basis of inulin clearance, in 114 ADPKD, and these mGFRs were compared with eGFRs calculated according to four basic equations: the MDRD, CKD-EPI, and JSN-CKDI equations and the Cockcroft-Gault formula, as well as the influence of tolvaptan and of inclusion of cystatin C on accuracy of the results. Accuracy of each of the seven total equations was evaluated on the basis of the percentage of eGFR values within mGFR ± 30% (P₃₀).

RESULTS

mGFRs were distributed throughout CKD stages 1-5. Regardless of the CKD stage, P₃₀s of the MDRD, CKD-EPI, and JSN-CKDI equations did not differ significantly between baseline values and on-tolvaptan values. In CKD 1-2 patients, P₃₀ of the CKD-EPI equation was 100.0%, whether or not the patient was on-tolvaptan. In CKD 3-5 patients, P₃₀s of the MDRD, CKD-EPI, and JSN-CKDI equations were similar. For all four equations, regression coefficients and intercepts did not differ significantly between baseline and on-tolvaptan values, but accuracy of the Cockcroft-Gault formula was inferior to that of the other three equations. Incorporation of serum cystatin C reduced accuracy.

CONCLUSIONS

The CKD-EPI equation is most reliable, regardless of the severity of CKD. Tolvaptain intake has minimal influence and cystatin C incorporation does not improve accuracy.

Serum total bilirubin concentration in patients with type 2 diabetes as a possible biomarker of polyvascular disease

AIMS

The aim of this study was to investigate the association between serum total bilirubin concentration and complicated macrovascular diseases, such as cerebrovascular disease (CBVD), cardiovascular disease (CAD), and peripheral arterial disease (PAD), in patients with type 2 diabetes.

METHODS

We performed a retrospective cross-sectional study in 674 patients with type 2 diabetes. Serum total bilirubin concentration was compared between patients with and without CBVD, CAD, and PAD. Logistic regression analyses were performed to identify risk factors for CBVD, CAD, and PAD. Associations between total bilirubin concentration and the number of complicated macrovascular diseases were analyzed.

RESULTS

Patients with CBVD and PAD showed significantly lower serum total bilirubin concentrations than did those patients without those diseases. However, the bilirubin concentration did not differ between patients with and without CAD. Total bilirubin concentration was an independent predictor of CBVD, but not of CAD or PAD. There was a statistically significant trend for a decrease in bilirubin concentration in the presence of an increasing number of macrovascular diseases.

CONCLUSION

The presence of more than one macrovascular disease, called polyvascular disease, carries a high risk for cardiovascular mortality. Serum total bilirubin concentration may be useful as a clinical biomarker of polyvascular disease.

Effect of Smoking Status on Monocyte Tissue Factor Activity, Carotid Atherosclerosis and Long-Term Prognosis in Metabolic Syndrome

BACKGROUND

Smoking increases the risk of atherothrombotic events. Tissue factor (TF) mainly expressed on monocytes plays an important role in thrombosis and atherosclerosis. Metabolic syndrome (MetS) is being increasingly recognized as a major atherothrombotic risk factor, but the effects of smoking on monocyte TF activity (MTFA), carotid atherosclerosis estimated on carotid intima-media thickness (CIMT), and long-term prognosis in MetS remain unclear.

METHODS AND RESULTS

A total of 301 MetS patients lacking any known cardiovascular disease were prospectively investigated and classified into 4 groups according to smoking status at entry and at 12 months as follows: never smokers, past smokers, quitters, and persistent smokers. Peripheral blood mononuclear cells (PBMC) were isolated, and MTFA was measured using a coagulation assay. Linear trends for higher baseline MTFA and CIMT were observed among persistent smokers, quitters, and past smokers compared with never smokers. At 12 months, MTFA and CIMT decreased in never and past smokers and quitters but increased in persistent smokers. Six acute myocardial infarctions and 8 strokes occurred during a median follow-up of 66.0 months. Persistent smoking was associated with an increased risk of events (P<0.001).

CONCLUSIONS

Smoking is associated with upregulated MTFA and progression of CIMT, which may be related to the risk of atherothrombotic events in MetS patients.

The Association between Glomerular Filtration Rate Estimated Using Different Equations and Mortality in the Japanese Community-Based Population: The Yamagata (Takahata) Study

Background

To evaluate renal function, the indices of estimated glomerular filtration rate (eGFR) obtained using several equations, including the Japanese versions of the serum creatinine-based MDRD equation (eGFRcreat), Chronic Kidney Disease Epidemiology Collaboration equation (eGFR-EPI), and serum cystatin C-based equation (eGFRcys), are utilized. This study prospectively examined the association between these eGFR values and all-cause mortality during a 12-year observational period in a community-based population.

Methods and Results

The subjects of this study were 1312 participants undergoing a health checkup, aged ≥40 years. In the total population, the mean eGFR values (mL·min⁻¹·1.73 m⁻²) were 81.5 for eGFRcreat, 78.1 for eGFR-EPI, and 76.6 for eGFRcys. There were 141 deaths during the observation period, and the area under the receiver operating characteristic curve for predicting mortality was 0.59 for eGFRcreat, 0.67 for eGFR-EPI, and 0.70 for eGFRcys (all P < 0.01). In the Cox proportional analysis adjusted for age and sex, eGFRcys, but not eGFRcreat and eGFR-EPI, showed a significant association with all-cause mortality (per 15 mL·min⁻¹·1.73 m⁻² decrease: hazard ratio 1.40, 95% confidence interval 1.18–1.67).

Conclusions

This study revealed that eGFRcys showed lower values than eGFRcreat and eGFR-EPI and was significantly associated with all-cause mortality in the Japanese community-based population.

Burden of high blood pressure as a contributing factor to stroke in the Japanese community-based diabetic population

Diabetes mellitus is characterized by alterations in blood glucose (BG) metabolism, and glycated hemoglobin (HbA₁c) has been widely used as a marker of the BG concentration. Diabetes often coexists with high blood pressure (BP). High BP and hyperglycemia are well-known risk factors of stroke. We examined the extent to which the increased risk of stroke in diabetic individuals is attributable to BP and BG using prospectively collected data from the Japanese general population. During an average 8.3 ± 2.2 years of follow-up, out 1606 diabetic individuals aged ≥40 years who were free of cardiovascular disease, 119 participants (7.4%) developed stroke. In multivariable analysis, a significant difference in the risk of incident stroke was noted among the BP categories, including normotension (BP1), prehypertension (BP2), and hypertension (BP3; P for trend = 0.001). By contrast, no difference was noted among the BG categories, including HbA₁c levels <7.0% (HB1), 7.0–7.9% (HB2), and ≥8.0% (HB3; P for trend = 0.430). Compared with the category that included both BP1 and HB1, the population-attributable fraction (PAF) for stroke incidence was 52.0% from the BP2 and BP3 categories and 24.1% from the HB2 and HB3 categories, and the increased incidence from the HB2 and HB3 categories was mostly caused from coexistent BP2 and BP3 categories. In conclusion, in the Japanese community-based diabetic population, concomitant BP elevation largely contributes to the increased incidence of stroke and links BG elevation, as indicated by HbA₁c, to the increased risk of stroke.

Interaction between gender and uric acid on hemoglobin A1c in community-dwelling persons

INTRODUCTION

Higher glycated hemoglobin (Hb) (HbA1c) is significantly associated with an increased risk of cardiovascular disease (CVD). Serum uric acid (SUA) levels are associated with glucose intolerance and type 2 diabetes. Whether gender-specific differences regarding the relationship between SUA levels and HbA1c exist is unknown.

AIM

We recruited 1636 (men, 696 aged of 70 ± 10 years; women, 940 aged of 70 ± 9 years) participants and enrolled in the study during their annual health examination from a single community. We investigated the association between SUA levels and HbA1c within each gender.

RESULTS

Multiple linear regression analysis showed that in men, SUA (β = -0.091, p = 0.014) with prevalence of antidiabetic medication (β = 0.428, p < 0.001) and eGFR (β = 0.112, p = 0.016) were significantly and negatively associated with HbA1c, and in women, SUA (β = 0.101, p = 0.002) with prevalence of antidiabetic medication (β = 0.458, p < 0.001) were significantly and positively associated with HbA1c. Moreover, the interaction between gender and SUA (β = 0.445, p < 0.001) as well as gender (β = -0.465, p < 0.001), prevalence of antidiabetic medication (β = 0.444, p < 0.001), eGFR_CKDEPI (β = 0.074, p = 0.014), and SUA (β = -0.356, p < 0.001) was a significant and independent determinant of HbA1c. A significant interactive effect of gender and SUA on determinants of HbA1c was noted in patients not on antidiabetic medications, regardless of age, HbA1c, and renal function.

CONCLUSIONS

The interaction between gender and SUA was associated with HbA1c independent of other metabolic factors in community-dwelling persons.

Ability of B-Type Natriuretic Peptide Testing to Predict Cardioembolic Stroke in the General Population - Comparisons With C-Reactive Protein and Urinary Albumin

BACKGROUND

The ability of cardiovascular biomarkers to predict the incidence of stroke subtypes remains ill-defined in the general population.

METHODS AND RESULTS

The blood levels of B-type natriuretic peptide (BNP) and high-sensitivity C-reactive protein (hs-CRP) and urinary albumin corrected by urinary creatinine (UACR) were determined in a general population (n=13,575). The ability to predict the incidence of ischemic stroke subtypes (lacunar, atherothrombotic, cardioembolic) for each biomarker was assessed based on the area under the receiver-operating characteristic curve (AUC-ROC) and using Cox proportional hazard modeling. The predictive abilities of UACR and hs-CRP for any subtype of ischemic event were found to be suboptimal. However, the ability of BNP to predict the incidence of cardioembolic stroke was excellent (AUC-ROC=0.81). When BNP was added to established stroke risk factors, the ability to predict cardioembolic stroke in terms of the AUC-ROC significantly improved (4-year follow-up, P=0.018; 8-year follow-up, P=0.009). Furthermore, when BNP was added to the JPHC score, the ability to predict cardioembolic stroke was significantly improved (net reclassification improvement=0.968, P<0.0001: integrated discrimination improvement=0.039, P<0.05).

CONCLUSIONS

In the general population, plasma BNP was an excellent biomarker for predicting the incidence of cardioembolic stroke when used alone or in combination with established stroke risk factors.

Estimated glomerular filtration ratio is a better index than creatinine clearance (Cockcroft-Gault) for predicting the prevalence of atrial fibrillation in the general Japanese population

Direct oral anti-coagulants (DOACs) have been used in patients with non-valvular atrial fibrillation (AF), and renal function evaluation using the CCr (Cockcroft-Gault) is recommended as a criterion for the reduction of DOAC. In contrast, estimated glomerular filtration rate (eGFR) is usually used as an index of renal function in daily practice. We determined the age- and gender-specific prevalence rates of AF and whether CCr or eGFR was associated with the prevalence of AF. Data from the periodic health examinations of 108,951 subjects were collected. Risk factors for AF were determined based on medical history, physical examinations and blood samples, and AF was diagnosed based on electrocardiography. The prevalence rate of AF was 0.92% (998/108,951). It was four times higher in men than in women and increased with age. Cardiac disease (odds ratio (OR) = 27.07, confidence interval (CI) 23.39-31.37, p = 0.0001), male gender (OR = 3.65, CI 3.11-4.30), age > 65 years (OR = 2.52, CI 2.14-2.96), hyperlipidemia (OR = 2.51, CI 1.97-3.20), BMI > 25 kg/m² (OR = 1.37, CI 1.19-1.58) and hypertension (OR = 1.14, CI 1.11-1.16) were independently associated with a high risk of AF in the multivariate logistic regression analysis. The odds ratio of having AF was significantly higher in patients with eGFR ≤ 59 (OR = 2.10, CI 1.21-3.86) than in those with eGFR ≥ 90 but was not associated with CCr after adjustments for age, gender, diabetes mellitus and smoking. The significance of this difference disappeared after additional adjustment for hypertension. Cardiac disease, gender, age, hyperlipidemia, obesity, hypertension and renal dysfunction were strong risk factors for AF. The evaluation of renal dysfunction as a morbidity risk factor for AF suggests that eGFR should be used.

The economic burden of kidney disorders in Korea

AIMS

To estimate the economic burden of kidney disorders in Korea.

MATERIALS AND METHODS

The economic burden of kidney disorders was estimated using a prevalence-based approach. Related kidney diseases in patients with kidney disorders (RPWKD) were defined using codes from the tenth International Classification of Disease (E70-E90, F30-F48, F60-F69, F90-F99, K65-K67, N00-N08, N17-N19, and N30-N39). All diseases in patients with kidney disorders (APWKD) were defined as kidney disorders that involved all disease codes. Economic costs were divided into direct costs (medical costs and non-medical costs) and indirect costs (productivity loss because of morbidity and premature mortality).

RESULTS

The prevalence of kidney disorders increased from 0.08% (2008) to 0.11% (2011). The total economic burden of RPWKD also substantially increased from $898.9 million (2008) to $1.43 billion (2011). This ∼59.4% increase in the economic burden was equal to 0.12% of the Korean gross domestic product. The economic burden of APWKD also increased during the study period: $1.06 billion (2008), $1.23 billion (2009), $1.44 billion (2010), and $1.46 billion (2011).

CONCLUSIONS

The present study provides the first data regarding the economic burden of kidney disorders in Korea. The findings support the need for early intervention services and prevention programs to prevent, identify, and manage kidney disorders.

Comparative evaluation of technetium-99m-diethylenetriaminepentaacetic acid renal dynamic imaging versus the Modification of Diet in Renal Disease equation and the Chronic Kidney Disease Epidemiology Collaboration equation for the estimation of GFR

PURPOSE

We compared the performance of technetium-99m-diethylenetriaminepentaacetic acid (^99mTc-DTPA) renal dynamic imaging (RDI), the MDRD equation, and the CKD EPI equation to estimate glomerular filtration rate (GFR).

METHODS

A total of 551 subjects, including CKD patients and healthy individuals, were enrolled in this study. Dual plasma sample clearance method of ^99mTc-DTPA was used as the true value for GFR (tGFR). RDI and the MDRD and CKD EPI equations for estimating GFR were compared and evaluated.

RESULTS

Data indicate that RDI and the MDRD equation underestimated GFR and CKD EPI overestimated GFR. RDI was associated with significantly higher bias than the MDRD and CKD EPI equations. The regression coefficient, diagnostic precision, and consistency of RDI were significantly lower than either equation. RDI and the MDRD equation underestimated GFR to a greater degree in subjects with tGFR ≥ 90 ml/min/1.73 m² compared with the results obtained from all subjects. In the tGFR60-89 ml/min/1.73 m² group, the precision of RDI was significantly lower than that of both equations. In the tGFR30-59 ml/min/1.73 m² group, RDI had the least bias, the most precision, and significantly higher accuracy compared with either equation. In tGFR < 30 ml/min/1.73 m², the three methods had similar performance and were not significantly different.

CONCLUSIONS

RDI significantly underestimates GFR and performs no better than MDRD and CKD EPI equations for GFR estimation; thus, it should not be recommended as a reference standard against which other GFR measurement methods are assessed. However, RDI better estimates GFR than either equation for individuals in the tGFR30-59 ml/min/1.73 m² group and thus may be helpful to distinguish stage 3a and 3b CKD.

Existing creatinine-based equations overestimate glomerular filtration rate in Indians

BACKGROUND

Accurate estimation of glomerular filtration rate (GFR) is important for diagnosis and risk stratification in chronic kidney disease and for selection of living donors. Ethnic differences have required correction factors in the originally developed creatinine-based GFR estimation equations for populations around the world. Existing equations have not been validated in the vegetarian Indian population. We examined the performance of creatinine and cystatin-based GFR estimating equations in Indians.

METHODS

GFR was measured by urinary clearance of inulin. Serum creatinine was measured using IDMS-traceable Jaffe's and enzymatic assays, and cystatin C by colloidal gold immunoassay. Dietary protein intake was calculated by measuring urinary nitrogen appearance. Bias, precision and accuracy were calculated for the eGFR equations.

RESULTS

A total of 130 participants (63 healthy kidney donors and 67 with CKD) were studied. About 50% were vegetarians, and the remainder ate meat 3.8 times every month. The average creatinine excretion were 14.7 mg/kg/day (95% CI: 13.5 to 15.9 mg/kg/day) and 12.4 mg/kg/day (95% CI: 11.2 to 13.6 mg/kg/day) in males and females, respectively. The average daily protein intake was 46.1 g/day (95% CI: 43.2 to 48.8 g/day). The mean mGFR in the study population was 51.66 ± 31.68 ml/min/1.73m2. All creatinine-based eGFR equations overestimated GFR (p < 0.01 for each creatinine based eGFR equation). However, eGFR by CKD-EPICys was not significantly different from mGFR (p = 0.38). The CKD-EPICys exhibited lowest bias [mean bias: -3.53 ± 14.70 ml/min/1.73m2 (95% CI: -0.608 to -0.98)] and highest accuracy (P30: 74.6%). The GFR in the healthy population was 79.44 ± 20.19 (range: 41.90-134.50) ml/min/1.73m2.

CONCLUSION

Existing creatinine-based GFR estimating equations overestimate GFR in Indians. An appropriately powered study is needed to develop either a correction factor or a new equation for accurate assessment of kidney function in the Indian population.

Interaction between body mass index and serum uric acid in relation to blood pressure in community-dwelling Japanese men

Background

Few data is available on the association between body mass index (BMI), serum uric acid (SUA) levels and blood pressure (BP) categories in the disease continuum, when efforts for its prevention may be applicable.

Methods

We performed a cross-sectional study to examine the association between BMI, SUA and BP in a community-dwelling sample of Japanese men. Individuals not on antihypertensive and uric acid lowering medications, and aged 50 to 90 years [817men aged 66 ± 9 (mean ± standard deviation) years] were recruited for the survey during a community based annual medical check-up. The main outcome was the presence of prehypertension [systolic BP (SBP) 120-139 mmHg and/or diastolic BP (DBP) 80-89 mmHg] and hypertension [SBP ≥ 140 and /or DBP ≥ 90].

Results

In participants with a BMI of < 21.0 kg/m², increased SUA levels were positively associated with SBP and DBP, but in those with a BMI of ≥ 21.0 kg/m², increased SUA levels were negatively associated with SBP and DBP. The interaction between BMI and SUA as well as BMI and SUA was a significant and independent determinant for both SBP (β = − 1.125, p = 0.001) and DBP (β = − 0.995, p = 0.005). Among participants, the respective prevalence of normotension, prehypertension, and hypertension was 19.5% and 53.7%, and 19.8%. The prevalence of normotension and prehypertension decreased with increasing BMI and the prevalence of hypertension increased with increasing BMI. In participants with a BMI ≥ 21.0 kg/m², the adjusted-odds ratio of SUA for hypertension was 0.75 (95% CI, 0.59-0.95) compared with normotension and 0.82 (0.70-0.96) compared with prehypertension. In those with a BMI of < 21.0 kg/m², these associations were not shown.

Conclusion

BMI may modify the association between SUA and blood pressure status among community-dwelling men.

Albuminuria Increases the Risks for Both Alzheimer Disease and Vascular Dementia in Community-Dwelling Japanese Elderly: The Hisayama Study

Background

Epidemiologic evidence has emerged to reveal an association of albuminuria and low estimated glomerular filtration rate (eGFR) with dementia, but the findings are inconsistent. In addition, there are limited studies addressing the association between albuminuria and Alzheimer disease (AD).

Methods and Results

A total of 1562 community‐dwelling Japanese subjects aged ≥60 years without dementia were followed up for 10 years. The outcomes were incidence of all‐cause dementia and its subtypes, namely, AD and vascular dementia (VaD). The hazard ratios for the outcomes were estimated according to urine albumin–creatinine ratio (UACR) and eGFR levels using a Cox proportional hazards model. During the follow‐up, 358 subjects developed all‐cause dementia (238 AD and 93 VaD). Higher UACR level was significantly associated with greater multivariable‐adjusted risks of all‐cause dementia (hazard ratios [95% confidence intervals]: 1.00 [reference], 1.12 [0.78–1.60], 1.65 [1.18–2.30], and 1.56 [1.11–2.19] for UACR of ≤6.9, 7.0–12.7, 12.8–29.9, and ≥30.0 mg/g, respectively), AD (1.00 [reference], 1.20 [0.77–1.86], 1.75 [1.16–2.64], and 1.58 [1.03–2.41], respectively), and VaD (1.00 [reference], 1.03 [0.46–2.29], 1.94 [0.96–3.95], and 2.19 [1.09–4.38], respectively). On the other hand, lower eGFR level was marginally associated with greater risk of VaD, but not AD. Subjects with UACR ≥12.8 mg/g and eGFR of <60 mL/min per 1.73 m² had 3.3‐fold greater risk of VaD than those with UACR <12.8 mg/g and eGFR of ≥60 mL/min per 1.73 m².

Conclusions

Albuminuria is a significant risk factor for the development of both AD and VaD in community‐dwelling Japanese elderly. Moreover, albuminuria and low eGFR are mutually associated with a greater risk of VaD.

Baseline and changes in serum uric acid independently predict glucose control among community-dwelling women

BACKGROUND

Elevated serum uric acid (SUA) levels are associated with glucose control. However, whether baseline and changes in SUA predict long-term follow-up glucose control [e.g., glycated hemoglobin (HbA1c)] remains unclear.

METHODS

The subjects comprised 393 women aged 71 ± 8 years and 279 men aged 71 ± 10 years from a rural village. We have identified participants who underwent a similar examination 11 years prior, and subjects were divided into four groups based on the tertiles of baseline and changes in SUA, and examined the relationship between baseline and changes in SUA, and glucose control evaluated by follow-up HbA1c after 11-years.

RESULTS

In both genders, follow-up SUA were significantly higher in Group 4 (i.e., women: Group 4, baseline SUA ≥ 4.0 mg/dL and changes in SUA ≥ 0.8 mg/dL; men: Group 4, ≥ 5.3 mg/dL and ≥ 0.4 mg/dL) than in the other Groups, but eGFR was significantly lower. Only in women, there were significant differences among the four groups regarding follow-up HbA1c, and follow-up HbA1c was highest in Group 4. In addition, the interaction between baseline and changes in SUA (F = 5.391, p = 0.021) as well as baseline low-density lipoprotein cholesterol (LDL-C) (F = 13.793, p < 0.001), estimated glomerular filtration ratio (F = 10.715, p = 0.001), HbA1c (F = 118.285, p < 0.001), SUA (F = 9.457, p = 0.002), and changes in SUA (F = 7.757, p = 0.006) was a significant and independent determinant of follow-up HbA1c. Multivariate-adjusted follow-up HbA1c (p = 0.002) were significantly higher in Group 4 than the other groups.

CONCLUSIONS

These results suggested that combined assessment of baseline and changes in SUA provides increased information for long-term predictive glucose control, independent of other confounding factors in community-dwelling women.

Glomerular Filtration Rates in Asians

The National Kidney Foundation Kidney Disease Outcomes Quality Initiative guidelines recommended the Modification of Diet in Renal Disease study equation for estimating glomerular filtration rate (GFR) for the classification of CKD, but its accuracy was limited to North American patients with estimated GFR <60 mL/min per 1.73 m2 body surface area of European (White) or African (Black) descent. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) developed another equation for estimating GFR, derived from a population that included both participants without kidney disease and with CKD. But many ethnicities were inadequately represented. The International Society of Nephrology, Kidney Disease Improving Global Outcomes committee promulgated clinical practice guidelines, which recommended the CKD-EPI equation. Investigators in Asia subsequently assessed the performance of these GFR estimating equations-the Modification of Diet in Renal Disease study equation, the CKD-EPI equation (creatinine only), and the CKD-EPI equations (creatinine and cystatin C). In this review, we summarize the studies performed in Asia on validating or establishing new Asian ethnicity GFR estimating equations. We included both prospective and retrospective studies which used serum markers traceable to reference materials and focused the review of the performance of GFR estimation by comparisons with the GFR estimations obtained from the CKD-EPI equations.

Pre-operative and post-operative estimated glomerular filtration rate in Japanese patients with urological malignancies

BACKGROUND

The suitable methods evaluating glomerular filtration rate (GFR) have not been established in patients undergoing radical nephrectomy (RN) or radical nephroureterectomy (RNU) due to urological malignancies in Japan as well as worldwide.

METHODS

We examined the relationship between creatinine clearance-based measured GFR (mGFR) versus estimated GFR (eGFR) calculated by 3 popular equations, 4-variable Modification of Diet in Renal Disease equation adjusted by Japanese correction coefficient (cmMDRD), 3-variable MDRD equation for Japanese population (eGFRcreat), and Chronic Kidney Disease-Epidemiology Collaboration equation adjusted by Japanese correction coefficient (cmCKD-EPI) in Japanese patients who had undergone RN or RNU due to renal cell carcinoma or upper tract urothelial carcinoma before and after surgery.

RESULTS

Among the 3 equations examined, eGFRcreat was the closest to mGFR, although each eGFR was significantly higher than mGFR in the pre-operative period. In the post-operative period, cmMDRD and eGFRcreat, but not cmCKD-EPI, were comparable to mGFR. Each of eGFR was significantly correlated with mGFR in both the pre-operative and post-operative periods. Similar results were obtained by the subanalysis of the patients with pre-operative mGFR of < 60 mL/min/1.73 m². Results of κ statistics also showed that eGFRcreat was most appropriate to estimate GFR both before and after heminephrectomy, when cut-off value of GFR of < 60 mL/min/1.73 m² was used.

CONCLUSION

Results of the present study suggest that eGFRcreat is likely to be the most appropriate equation for patients undergoing RN or RNU due to urological malignancies. However, more precise equations will be required for accurately estimating GFR.

Glomerular hyperfiltration is a predictor of adverse cardiovascular outcomes

The association between glomerular hyperfiltration and cardiovascular events is not well known. To investigate whether glomerular hyperfiltration is independently associated with risk of adverse outcome we analyzed 8794 participants, average age 52 years enrolled in 8 prospective studies. Of these, 89% had hypertension. Using the 5th and 95th percentiles of the age- and sex-specific quintiles of CKD-EPI-calculated estimated glomerular filtration rate (eGFR), we identified three participant groups with low, high and normal eGFR. The ambulatory pulse pressure interval was wider and nighttime blood pressure fall was smaller in both the low and high than in the normal eGFR participants. During a mean follow-up of 6.2 years, there were 722 cardiovascular events. Crude event rates were significantly higher for both high (1.8 per 100-person-year) and low eGFR groups (2.1 per 100 person-year) as compared with group with normal eGFR (1.2 per 100 person-year). In multivariable Cox models including age, sex, average 24-hour blood pressure, smoking, diabetes, and cholesterol, both high eGFR (hazard ratio 1.5 (95% confidence interval 1.2-2.1) and low eGFR (2.0 [1.5-2.6]) participants had a significantly higher risk of cardiovascular events as compared to those with normal eGFR. Addition of body mass index to the multivariable survival model did not change the magnitude of hazard estimates. Thus, glomerular hyperfiltration is a strong and independent predictor of cardiovascular events in a large multiethnic population of predominantly hypertensive individuals. Our findings support a U-shaped relationship between eGFR and adverse outcome.

Association between serum uric acid level and renal arteriolar hyalinization in individuals without chronic kidney disease

BACKGROUND AND AIMS

Recent studies have reported an association between serum uric acid (SUA) and renal arteriolar changes in patients with chronic kidney disease (CKD). However, the association in individuals without CKD remains unclear. In this study, we investigated the relationship between SUA and renal arteriolar lesions in individuals without CKD from our living kidney donor cohort.

METHODS

Between January 2006 and May 2016, 393 living kidney donors underwent "time-zero" biopsy at Kyushu University Hospital. Patients were divided into sex-specific quartiles of SUA before donation: Q1, Q2, Q3, and Q4 (male: <5.2,5.2-5.8,5.9-6.4, and ≥6.5 mg/dL, female: <3.8,3.8-4.3,4.4-5.0, and ≥5.1 mg/dL). Renal arteriolar hyalinization and wall thickening were assessed using a semiquantitative grading system. Predictive performance was compared between models with and without SUA by calculating the net reclassification improvement (NRI).

RESULTS

In total, 158 (40.2%) patients had arteriolar hyalinization, and 148 (37.6%) had wall thickening. High SUA was significantly associated with arteriolar hyalinization in multivariable logistic analysis (odds ratio [OR] per 1-mg/dL increase in SUA, 1.24; 95% confidence interval [CI], 1.00-1.53; p = 0.048. OR for Q4 vs. Q2, 2.22; 95% CI, 1.17-4.21; p = 0.01). We found no association between SUA and wall thickening. When SUA was incorporated into a predictive model with conventional atherosclerotic factors, the NRI was 0.21 (p = 0.04).

CONCLUSIONS

High SUA was an independent risk factor for arteriolar hyalinization in individuals without CKD. SUA provided additional predictive value beyond conventional atherosclerotic factors in predicting arteriolar hyalinization.

Alanine Aminotransferase and Total Bilirubin Are Synergistically Associated with Metabolic Syndrome Among Middle-Aged and Elderly Japanese Women

BACKGROUND

Metabolic syndrome (MetS) is associated with an increased risk of major cardiovascular events. Alanine aminotransferase (ALT) at high levels and total bilirubin (T-BiL) at low levels were oxidative potentials, but it was uncertain whether ALT and T-BiL had an additive interaction for the risk of MetS.

METHODS

From a single community, we recruited 864 women (70 ± 8 years) during their annual health examination. We cross-sectionally investigated whether ALT and T-BiL are associated with MetS and its components based on the modified criteria of the National Cholesterol Education Program's Adult Treatment Panel (NCEP-ATP) III report.

RESULTS

Of these subjects, 415 women (48.0%) had MetS. Participants with MetS had a higher ALT and lower T-BiL level than those without MetS. The adjusted-odds ratios (OR) (95% confidence interval [CI]) for MetS across tertiles of ALT and T-BiL were 1.00, 1.19 (0.78-1.81), and 1.86 (1.24-2.80) and 1.00, 0.96 (0.65-1.43), and 0.54 (0.36-0.81), respectively. When ALT and T-BiL were categorized into three binary characteristics by tertiles of ALT and T-BiL, high T-BiL was associated with decreased risk for MetS in a multivariable model (OR: 0.55, 95% CI: 0.37-0.82), especially among those with 1st tertile ALT. Similarly, high ALT was also associated with increased risk for MetS in a multivariate model (OR: 1.81, 95% CI: 1.20-2.71), especially among those with 2nd & 3rd tertiles of T-BiL. In the formal testing of addictive interaction between ALT and T-BiL for MetS, presence of T-BiL <0.72 mg/dL (1st and 2nd tertile) alone was not associated with increased risk of MetS in a multivariate analysis, and presence of ALT ≥16 IU/L (2nd and 3rd tertile) alone was not associated with increased risk of MetS.

CONCLUSIONS

These results suggested that higher ALT and lower T-BiL levels were synergistically associated with MetS, independent of other confounding factors among Japanese women.

Paratubular basement membrane insudative lesions predict renal prognosis in patients with type 2 diabetes and biopsy-proven diabetic nephropathy

AIMS

Glomerular insudative lesions are a pathological hallmark of diabetic nephropathy (DN). However, paratubular basement membrane insudative lesions (PTBMIL) have not attracted much attention, and the association between such lesions and the renal prognosis remains unclear.

METHODS

Among 142 patients with biopsy-proven DN and type 2 diabetes encountered from 1998 to 2011, 136 patients were enrolled in this study. Patients were classified into 3 groups (Group 1: mild, Group 2: moderate, Group 3: severe) according to the extent of cortical and medullary PTBMIL. The endpoint was a decline of the estimated glomerular filtration rate (eGFR) by ≥ 40% from baseline or commencement of dialysis for end-stage renal disease. The Cox proportional hazard model was employed to calculate hazard ratios (HRs) and 95% confidence interval (CIs) for the death-censored endpoint.

RESULTS

During a median follow-up period of 1.8 years (IQR: 0.9-3.5), the endpoint occurred in 104 patients. Baseline mean eGFR was 43.9 ± 22.8 ml/min/1.73 m2, and 125 patients (92%) had overt proteinuria. After adjusting for known indicators of DN progression, the HR for the endpoint was 2.32 (95% CI: 1.20-4.51) in PTBMIL Group 2 and 3.12 (1.48-6.58) in PTBMIL Group 3 versus PTBMIL Group 1. Furthermore, adding the PTBMIL Group to a multivariate model including known promoters of DN progression improved prediction of the endpoint (c-index increased by 0.02 [95% CI: 0.00-0.04]).

CONCLUSIONS

PTBMIL may be useful for predicting the renal prognosis of patients with biopsy-proven DN, but further investigation of these lesions in various stages of DN is needed.

Association between renal function and outcomes after percutaneous transluminal renal angioplasty in hypertensive patients with renal artery stenosis

OBJECTIVE

We investigated the impact of renal function on outcomes after percutaneous transluminal angioplasty.

METHODS

A total of 139 hypertensive patients with atherosclerotic renal artery stenosis (mean age, 70 years, 80.6% men) who underwent renal percutaneous transluminal angioplasty were included. Renal function was evaluated on the basis of estimated glomerular filtration rate (eGFR) and albuminuria/proteinuria, and classified into three categories according to eGFR (≥45, 30-44, and <30 ml/min/1.73 m) and albuminuria/proteinuria [normal-to-mild: albumin/creatinine ratio (ACR) less than 3.0, protein/creatinine ratio (PCR) less than 15; moderate: ACR 3.0-30.0, PCR 15-50; severe: ACR > 30.0, PCR > 50 mg/mmol].

RESULTS

During a median follow-up of 5.4 years, 36.0% of patients developed the primary composite end point, including cardiovascular and renal outcomes. In multivariate Cox regression analysis, eGFR less than 30 (hazard ratio 3.47, P < 0.01) as well as severe albuminuria/proteinuria (hazard ratio 2.63, P < 0.05) was an independent predictor of worse outcome. In the subgroup without events within 1 year after angioplasty (n = 117), the outcome differed among the three renal functional categories at 1 year based on eGFR (log-rank χ = 16.28, P < 0.001) as well as on albuminuria/proteinuria (log-rank χ = 8.30, P < 0.05). At 1 year, 24 patients (20.1%) showed at least 20% decrease in eGFR, and their outcome was worse than that in those with at least 20% increase (n = 23) (hazard ratio 3.50, P < 0.05). Multiple logistic regression analysis indicated that pretreatment moderate-to-severe albuminuria/proteinuria was an independent predictor of at least 20% eGFR decrease (odds ratio 2.82, P < 0.05).

CONCLUSION

Impaired renal function, and in particular, a poor response of eGFR to angioplasty, is associated with worse outcome. Therapeutic effectiveness of renal angioplasty seems to be limited in patients with albuminuria/proteinuria.

The Contribution of Inflammation to the Development of Hypertension Mediated by Increased Arterial Stiffness

BACKGROUND

The mechanisms underlying the possible contribution of chronic inflammation to the development of hypertension remain unclear. We examined the longitudinal association of inflammation with the progression of vascular and/or renal abnormalities in the development of hypertension.

METHODS AND RESULTS

In 3274 middle-aged Japanese men without hypertension at the study baseline, brachial-ankle pulse wave velocity, blood pressure, estimated glomerular filtration rate, and serum CRP (C reactive protein) levels were measured annually during a 9-year period. During this study period, 474 participants (14.5%) developed hypertension. Analysis of the repeated-measures data revealed that sustained elevation of serum CRP levels was associated with a longitudinal increase of the brachial-ankle pulse wave velocity. A linear mixed model analysis revealed that higher log-transformed serum CRP values (log CRP) at each measurement were associated with a higher annual increase of the brachial-ankle pulse wave velocity (estimate=32.553±11.635 cm/s per log CRP, P=0.018), and that higher values of the brachial-ankle pulse wave velocity at each measurement were associated with a higher annual elevation of blood pressure (estimate=0.025±0.002 mm Hg per log CRP, P<0.001).

CONCLUSIONS

In middle-aged Japanese men without hypertension at study baseline, long-term active inflammation appears to be associated with a longitudinal increase of arterial stiffness. In turn, this longitudinal increase of arterial stiffness appears to be associated with longitudinal elevation of blood pressure to the hypertensive range. Thus, systemic inflammation may play a role in the pathogenesis of hypertension by the progression of arterial stiffness.

Interactive association of serum uric acid and total bilirubin with renal dysfunction among community-dwelling subjects

PURPOSE

Chronic kidney disease is a major public health concern. Serum uric acid (SUA) at high levels was oxidative stress agents, and total bilirubin (T-BiL) at mildly increased levels was potent antioxidants, but whether SUA and T-BiL produce an additive interaction for the risk of renal dysfunction remains unclear.

METHODS

The subjects comprised 567 men aged 71 ± 8 (mean ± standard deviation) years and 853 women aged 70 ± 8 years from a rural village. We examined the relationship between SUA and T-BiL, and renal function was evaluated by estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease Study Group equation.

RESULTS

Stepwise multiple regression analysis using eGFR as an objective variable, adjusted for risk factors as explanatory variables, showed that SUA (β = -0.358, p < 0.001) as well as age (β = -0.534, p < 0.001), drinking status (β = 0.119, p < 0.001), and the presence of antihypertensive medication (β = -0.058, p = 0.005) were significantly and independently associated with eGFR, but T-BiL was not associated with eGFR. While in the group with the highest tertile of SUA, T-BiL (β = 0.081, p = 0.032) was significantly and independently associated with eGFR, and in the group with the lowest to middle tertile of SUA, T-BiL was not associated with eGFR. In addition, interaction between SUA and T-BiL (F = 8.512, p = 0.004) as well as age, drinking status, the presence of antihypertensive medication, SUA, and T-BiL was a significant and independent determinant for eGFR.

CONCLUSIONS

Our data demonstrated that low T-BiL could be important as a potential risk factor for renal dysfunction in those with high SUA.

Chronic kidney disease in low-income to middle-income countries: the case for increased screening

Chronic kidney disease (CKD) is fast becoming a major public health issue, disproportionately burdening low-income to middle-income countries, where detection rates remain low. We critically assessed the extant literature on CKD screening in low-income to middle-income countries. We performed a PubMed search, up to September 2016, for studies on CKD screening in low-income to middle-income countries. Relevant studies were summarised through key questions derived from the Wilson and Jungner criteria. We found that low-income to middle-income countries are ill-equipped to deal with the devastating consequences of CKD, particularly the late stages of the disease. There are acceptable and relatively simple tools that can aid CKD screening in these countries. Screening should primarily include high-risk individuals (those with hypertension, type 2 diabetes, HIV infection or aged >60 years), but also extend to those with suboptimal levels of risk (eg, prediabetes and prehypertension). Since screening for hypertension, type 2 diabetes and HIV infection is already included in clinical practice guidelines in resource-poor settings, it is conceivable to couple this with simple CKD screening tests. Effective implementation of CKD screening remains a challenge, and the cost-effectiveness of such an undertaking largely remains to be explored. In conclusion, for many compelling reasons, screening for CKD should be a policy priority in low-income to middle-income countries, as early intervention is likely to be effective in reducing the high burden of morbidity and mortality from CKD. This will help health systems to achieve cost-effective prevention.

Clinical significance of serum complement factor 3 in patients with type 2 diabetes mellitus

AIMS

Although serum complement factor 3 (C3) is an acute phase reactant mainly synthesized in the liver, several recent studies have shown high C3 gene expression in adipose tissue (AT). However, the relationship between C3 and AT levels has not been fully clarified in type 2 diabetes mellitus (T2DM) patients.

METHODS

A total of 164 T2DM patients (109men and 55 women) participated in this cross-sectional study. A computed tomography scan was performed to measure visceral, subcutaneous, and total AT. The correlation between these factors and C3 levels was examined using Pearson's correlation analysis. A multivariate regression model was used to assess an independent determinant associated with C3 levels after adjusting the explanatory variables (i.e., all ATs [visceral, subcutaneous, and total], and clinical features [sex, age, body mass index, waist circumference, glycated hemoglobin, duration of diabetes, systolic blood pressure, diastolic blood pressure, aspartate aminotransferase levels, alanine aminotransferase levels, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, log(triglyceride levels), estimated glomerular filtration rate, and log(high-sensitivity C-reactive protein levels)]).

RESULTS

Serum C3 levels were correlated with visceral, subcutaneous, and total AT among both men (r=0.505, p<0.001; r=0.545, p<0.001; r=0.617, p<0.001, respectively) and women (r=0.396, p=0.003; r=0.517, p<0.001; r=0.548, p<0.001, respectively). In the multivariate regression model, the association between total AT and C3 levels remained significantly positive (β=0.490, p<0.001).

CONCLUSIONS

Serum C3 levels are associated with visceral, subcutaneous, and total AT in T2DM patients. Furthermore, C3 levels seem to be a marker for overall adiposity rather than regional adiposity.

Nodular lesions in diabetic nephropathy: Collagen staining and renal prognosis

AIMS

Nodular lesions are one of the most characteristic pathological changes of advanced diabetic nephropathy (DN). Previous studies have demonstrated that the pattern of both routine and collagen staining of nodular lesions changes during their development. However, the association between such changes of staining and the renal prognosis remains unclear.

METHODS

Among 252 patients with biopsy-proven DN, 67 met the selection criteria and were enrolled to investigate this relationship. In all patients, nodular lesions were stained with periodic acid Schiff, periodic acid methenamine silver, and Masson trichrome stains, and immunostaining was done for type I, III, IV, V, and VI collagen. The endpoint was commencement of dialysis due to end-stage renal disease.

RESULTS

At least one mesangiolytic nodular lesion (MNL) that showed faint staining for PAS and PAM was found in 61% of the patients. MNLs were negative for type IV collagen staining, unlike the strong positivity of non-MNLs, while type V and VI collagen staining were strongly positive in all nodular lesions. Cox proportional hazards regression analysis revealed that the hazard ratio (HR) for the endpoint was significantly higher in patients with at least one MNL than in patients with no MNLs after adjustment for known promoters of renal progression (HR: 2.94; 95% confidence interval: 1.24-7.07).

CONCLUSIONS

MNLs may reflect characteristic differences of collagen production and could be a useful prognostic indicator in patients with nodular lesions. Further investigation of the mechanism underlying these differences of collagen production could contribute to finding new therapeutic targets for DN.