Prevalence of chronic kidney disease in the Japanese general population

Use of sodium-glucose co-transporter-2 inhibitors in Asian patients with type 2 diabetes and kidney disease: An Asian perspective and expert recommendations

Early onset of type 2 diabetes and a high prevalence of co-morbidities predispose the Asian population to a high risk for, and rapid progression of, diabetic kidney disease (DKD). Apart from renin-angiotensin system inhibitors, sodium-glucose co-transporter-2 (SGLT-2) inhibitors have been shown to delay renal disease progression in patients with DKD. In this review article, we consolidate the existing literature on SGLT-2 inhibitor use in Asian patients with DKD to establish contemporary guidance for clinicians. We extensively reviewed recommendations from international and regional guidelines, data from studies on Asian patients with DKD, global trials (DAPA-CKD, CREDENCE and DELIGHT) and cardiovascular outcomes trials. In patients with DKD, SGLT-2 inhibitor therapy significantly reduced albuminuria and the risk of hard renal outcomes (defined as the onset of end-stage kidney disease, substantial decline in renal function from baseline and renal death), cardiovascular outcomes and hospitalization for heart failure. In all the cardiovascular and renal outcomes trials, there was an initial decline in the estimated glomerular filtration rate (eGFR), which was followed by a slowing in the decline of renal function compared with that seen with placebo. Despite an attenuation in glucose-lowering efficacy in patients with low eGFR, there were sustained reductions in body weight and blood pressure, and an increase in haematocrit. Based on the available evidence, we conclude that SGLT-2 inhibitors represent an evidence-based therapeutic option for delaying the progression of renal disease in Asian patients with DKD and preserving renal function in patients at high risk of kidney disease.

Association between serum sodium level within normal range and handgrip strength in relation to hypertension status: a cross-sectional study

Serum sodium concentration within the normal range could act as an indicator of age-related changes such as decrease in muscle strength and impairment of capillary function. Since endothelial injury stimulates endothelial repair by enhancing CD34-positive cell production, the level of serum sodium may be inversely associated with that of circulating CD34-positive cells, thus indicating the degree of age-related endothelial injury. We conducted a cross-sectional study of 246 elderly Japanese men aged 60–69 years. Subjects were stratified by hypertension status because hypertension should act as a strong confounding factor for the analyses performed in this study. Serum sodium concentration was positively associated with handgrip strength in non-hypertensive subjects [standardized parameter estimate (β) = 0.29; p = 0.003], but not for hypertensive subjects (β = 0.01; p = 0.878), while it was inversely associated with circulating CD34-positive cell levels in non-hypertensive subjects [simple correlation coefficient (r) = − 0.28; p = 0.002] but not for hypertensive subjects (r = − 0.07; p = 0.454). For non-hypertensive elderly subjects, serum sodium concentration within the normal range is positively associated with handgrip strength and inversely associated with CD34-positive cells, thus partly indicating the degree of age-related endothelium injury. These associations could prove to be an efficient tool for clarifying the background mechanism governing the decrease in age-related muscle strength.

Determining the factors affecting serum presepsin level and its diagnostic utility: A cross-sectional study

INTRODUCTION

This study aimed to identify factors affecting presepsin levels and to determine their diagnostic utility.

METHODS

This cross-sectional study was conducted at an outpatient clinic and emergency department at an acute care hospital in Japan between January 2015 and December 2017. We enrolled 1,840 consecutive outpatients with at least one measurement of serum presepsin, who were suspected of having bacterial infection. The outcome variables were bacterial infection, lower respiratory tract infection, urinary tract infection, cholangitis, and other infections diagnoses, based on the chart review. We collected blood analysis data on the patients' presepsin levels.

RESULTS

There was a significant association between presepsin level and the diagnosis of bacterial infection even when adjusted for age, sex, renal function, and biliary enzyme levels. An increase of 1 unit in the log of presepsin values resulted in a relative risk ratio of 1.71 (1.09-2.66), 2.1 (1.58-2.79), 2.93 (2.05-4.19), 4.7(2.90-7.61), and 2.41(1.70-3.43), for bacterial infection, lower respiratory tract infection, urinary tract infection, cholangitis, and other infections, respectively.

CONCLUSIONS

Presepsin showed a statistically significant increase in the diagnosis of bacterial infections (lower respiratory tract infections, urinary tract infections, cholangitis, and non-severe patients) in a community hospital setting. However, in patients with renal dysfunction, presepsin levels should be interpreted with caution.

Dysbiosis in the Salivary Microbiome Associated with IgA Nephropathy-‍A‍ ‍Japanese Cohort Study

IgA nephropathy is one of the leading causes of chronic kidney disease in Japan. Since the origin and mechanisms by which IgA nephropathy develops currently remain unclear, a confirmed disease diagnosis is currently only possible by highly invasive renal biopsy. With the background of the salivary microbiome as a rich source of biomarkers for systemic diseases, we herein primarily aimed to investigate the salivary microbiome as a tool for the non-invasive diagnosis of IgA nephropathy. In a comparison of salivary microbiome profiles using 16S rRNA amplicon sequencing, significant differences were observed in microbial diversity and richness between IgA nephropathy patients and healthy controls. Furthermore, recent studies reported that patients with IgA nephropathy are more likely to develop inflammatory bowel diseases and that chronic inflammation of the tonsils triggered the recurrence of IgA nephropathy. Therefore, we compared the salivary microbiome of IgA nephropathy patients with chronic tonsillitis and ulcerative colitis patients. By combining the genera selected by the random forest algorithm, we were able to distinguish IgA nephropathy from healthy controls with an area under the curve (AUC) of 0.90, from the ulcerative colitis group with AUC of 0.88, and from the chronic tonsillitis group with AUC of 0.70. Additionally, the genus Neisseria was common among the selected genera that facilitated the separation of the IgA nephropathy group from healthy controls and the chronic tonsillitis group. The present results indicate the potential of the salivary microbiome as a biomarker for the non-invasive diagnosis of IgA nephropathy.

Autologous Blood Donation Before Hepatectomy in Patients With Chronic Kidney Disease

Autologous blood is sometimes collected before hepatectomy. The usefulness of autologous blood donation (ABD) has been reported in several studies. However, the relationship between ABD and CKD has never been studied. The aim of this study was to clarify the relationship between preoperative autologous blood donation (ABD) and chronic kidney disease (CKD) in anemia. Between January 2006 and December 2012, 70 patients made 2 ABDs ≥ 600 mL before hepatectomy. CKD stages were based on estimated glomerular filtration rates. Univariate analyses were performed using the Mann–Whitney U test for continuous variables and the chi-square test for nominal variables. Patients at CKD stages < G3b (n = 60) and ≥ G3b (n = 10) were compared. There were no significant differences in hemoglobin level at the initial hospital visit or total volume of ABD between the 2 groups. However, hemoglobin levels just before the first ABD, the second ABD, and resection, and just after resection were significantly lower in the CKD ≥ G3b group than those in the < G3b group (P < 0.05). CKD stage contributes to reductions in hemoglobin levels after ABD. We recommend the use of erythropoietin in CKD ≥ G3b cases that include ABDs.

Vadadustat for anemia in chronic kidney disease patients on peritoneal dialysis: A phase 3 open-label study in Japan

Vadadustat is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor for the treatment of anemia in patients with chronic kidney disease (CKD). This phase 3, open-label, 24-week single-arm study evaluated the efficacy and safety of vadadustat in 42 Japanese CKD patients with anemia undergoing peritoneal dialysis. Patients received oral vadadustat for 24 weeks, initiated at 300 mg/day and doses were adjusted to achieve the target hemoglobin (Hb) range of 11.0-13.0 g/dL. Least squares mean of average Hb at weeks 20 and 24 was 11.35 g/dL, which was within the target range. The most frequent adverse events were catheter site infections (23.8%), which were not related to vadadustat treatment. Vadadustat was generally well tolerated and effective in controlling Hb levels within the target range, indicating the usefulness of vadadustat for treating anemia in Japanese CKD patients undergoing peritoneal dialysis.

Relationships of Fat and Muscle Mass with Chronic Kidney Disease in Older Adults: A Cross-Sectional Pilot Study

This cross-sectional pilot study aimed to assess the relationships of fat and muscle mass with chronic kidney disease (CKD) in older adults. Serum creatinine concentration was used to measure estimated glomerular filtration rate (mL/min/1.73 m²) in the 236 subjects, who were allocated to three groups: a normal (≥60.0), a mild CKD (45.0–59.9), and a moderate to severe CKD (<45.0) group. The Jonckheere-Terpstra test and multivariate logistic regression were employed to assess body composition trends and the relationships of % fat mass (FM) or % muscle mass index (MMI) with moderate-to-severe CKD. Body weight, fat-free mass, MMI, and %MMI tended to decrease with an increase in the severity of CKD, but the opposite trend was identified for %FM. No relationship with BMI was identified. The participants in the middle-high and highest quartile for %FM were 6.55 and 14.31 times more likely to have moderate to severe CKD. Conversely, the participants in the highest quartile for %MMI were 0.07 times less likely to have moderate to severe CKD. Thus, high fat and low muscle mass may be more strongly associated with CKD than obesity per se.

Pelvic exenteration associated with future renal dysfunction

PURPOSE

This study aimed to clarify the long-term change in the renal function after pelvic exenteration (PE) and to evaluate the risk factors for any future dysfunction.

METHODS

This study comprised 40 patients. A greater than 25% decline in the estimated glomerular filtration rate (eGFR) at 3 years was defined as early renal function disorder (ERFD), possibly predicting future chronic kidney disease (CKD).

RESULTS

In the entire cohort, the median eGFR decreased by 23% at 3 years, and CKD developed in 50%. The patients were divided into the ERFD (n = 16) and non-ERFD (n = 24) groups. In the ERFD group, the eGFR significantly decreased by 28% during the first 1.5 years and continued to decline after that, resulting in 81.3% of patients reaching CKD, whereas it was 4% and 37.5%, respectively, in the non-ERFD group. In a growth model analysis, late urinary tract complications (UTC) and small bowel obstruction were shown to be risk factors for ERFD.

CONCLUSION

Although PE was associated with a high incidence of future CKD, ERFD could predict it. Close observation of the eGFR decline over 1.5 years might be beneficial to identify ERFD patients. High-risk patients with late UTC and small bowel obstruction should, therefore, be observed carefully.

Age differences in the relationships between risk factors and loss of kidney function: a general population cohort study

BACKGROUND

Annual decline in kidney function is a widely applied surrogate outcome of renal failure. It is important to understand the relationships between known risk factors and the annual decline in estimated glomerular filtration rate (eGFR) according to baseline age; however, these remain unclear.

METHODS

A community-based retrospective cohort study of adults who underwent annual medical examinations between 1999 and 2013 was conducted. The participants were stratified into different age groups (40-49, 50-59, 60-69, 70-79, and ≥ 80 years) to assess the risk for loss of kidney function. A mixed-effects model was used to estimate the association between risk factors and annual changes in eGFR.

RESULTS

In total, 51,938 participants were included in the analysis. The age group of ≥80 years included 8127 individuals. The mean annual change in eGFR was - 0.39 (95% confidence interval: - 0.41 to - 0.37) mL/min/1.73 m² per year. Older age was related to faster loss of kidney function. In the older age group, higher systolic blood pressure, proteinuria, and current smoking were related to faster loss of kidney function (p trend < 0.01, 0.03, and < 0.01, respectively). Conversely, each age group showed similar annual loss of kidney function related to lower hemoglobin levels and diabetes mellitus (p trend 0.47 and 0.17, respectively).

CONCLUSIONS

Higher systolic blood pressure, proteinuria, and smoking were related to faster loss of kidney function, and a greater effect size was observed in the older participants. More risk assessments for older people are required for personalized care.

Elevated alanine aminotransferase and low aspartate aminotransferase/alanine aminotransferase ratio are associated with chronic kidney disease among middle-aged women: a cross-sectional study

BACKGROUND

Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) to ALT ratio (AST/ALT ratio) have been shown to be related to non-alcoholic fatty liver disease or insulin resistance, which was associated with chronic kidney disease (CKD). However, it is unclear whether ALT and AST/ALT ratio are associated with CKD. In this study, we examined the relationship of ALT and AST/ALT ratio to CKD among middle-aged females in Japan.

METHODS

The present study included 29,133 women aged 40 to 64 years who had an annual health checkup in Japan during April 2013 to March 2014. Venous blood samples were collected to measure ALT, AST, gamma-glutamyltransferase (GGT), and creatinine levels. In accordance with previous studies, ALT > 40 U/L and GGT > 50 U/L were determined as elevated, AST/ALT ratio < 1 was regarded as low, and CKD was defined as estimated glomerular filtration rate < 60 mL/min/1.73 m² and/or proteinuria. Logistic regression model was used to calculate the odds ratio (OR) and 95% confidence interval (CI) for CKD.

RESULTS

"Elevated ALT and elevated GGT" and "elevated ALT and non-elevated GGT" significantly increased the OR for CKD when compared with "non-elevated ALT and non-elevated GGT" (OR: 2.56, 95% CI: 2.10-3.12 and OR: 2.24, 95% CI: 1.81-2.77). Compared with "AST/ALT ratio ≥ 1 and non-elevated GGT", "AST/ALT ratio < 1 and elevated GGT" and "AST/ALT ratio < 1 and non-elevated GGT" significantly increased the OR for CKD (OR: 2.73, 95% CI: 2.36-3.15 and OR: 1.68, 95% CI: 1.52-1.87). These findings still remained after adjustment for confounders.

CONCLUSIONS

Elevated ALT was associated with CKD regardless of GGT elevation. Moreover, low AST/ALT ratio was also associated with CKD independent of GGT elevation.

Relationships of Fatty Acids, Delta-5 Desaturase Activity, and Lipid Profiles in Men with Acute Coronary Syndrome

AIMS

We evaluated the relationship between the ratios of eicosapentaenoic acid and arachidonic acid (EPA/AA), docosahexaenoic acid (DHA)/AA, and delta-5 desaturase activity (D5D) and atherogenic lipid profiles (ALP) and coronary atherosclerosis.

METHODS

Polyunsaturated fatty acids (PUFA) and ALP were assessed in 436 men with the first episode of acute coronary syndrome (ACS) not take any lipid-lowering drugs. D5D was estimated as the ratio of AA to dihomogamma-linolenic acid (DGLA). These biomarkers were compared between the lower and higher levels of EPA/AA (0.41) or DHA/AA (0.93) according to the levels in Japanese general population. The thrombolysis in myocardial infarction flow (TIMI) grade of the culprit coronary artery was visually estimated during the initial angiography.

RESULTS

Approximately 70% of patients had low EPA/AA or DHA/AA. Serum levels of LDL-cholesterol, apolipoprotein B (apoB), and remnant lipoprotein cholesterol (RL-C) were significantly higher in the low EPA/AA or DHA/AA groups, while those of triglycerides and malondialdehyde-modified LDL (MDA-LDL) were significantly higher in the low EPA/AA group alone. The levels of EPA, EPA/AA, DHA/AA, and HbA1c increased and those of DGLA and apoA1 decreased with increasing number of stenotic vessels. Patients with three stenotic coronary vessels or TIMI grade ≥ 1 had significantly higher EPA levels compared with the others. The levels of LDL-cholesterol, non-HDL-cholesterol, triglycerides, small dense LDL-cholesterol, RL-C, MDA-LDL, apoB, and apoE decreased progressively and those of EPA, DHA, EPA/AA and HDL-cholesterol increased as D5D increased.

CONCLUSIONS

The EPA/AA is a superior risk marker than DHA/AA in term of correlation with ALP in ACS patients.

Risk of higher dose methotrexate for renal impairment in patients with rheumatoid arthritis

Renal impairment is a major concern in patients taking high-dose methotrexate (MTX) for malignancy, but it has not been fully explored in rheumatoid arthritis (RA) patients taking low-dose MTX. This study aimed to elucidate the dose-dependent effects of MTX on the renal function of patients with RA. We retrospectively reviewed 502 consecutive RA patients who were prescribed MTX for ≥ 1 year at Okayama University Hospital between 2006 and 2018. The primary outcome was the change in estimated glomerular filtration rate (eGFR) over 1 year. The association between MTX dosage (< 8, 8-12, and ≥ 12 mg/week) and the change in eGFR was evaluated using multiple linear regression analysis with adjustment for possible confounding factors including age, sex, disease duration, body weight, comorbidity, baseline eGFR, concomitant treatment, and disease activity. Mean patient age was 63 years; 394 (78%) were female. Median disease duration was 77 months, while mean MTX dosage was 8.6 mg/week. The last 1-year change of eGFR (mean ± SD) in patients treated with MTX < 8 (n = 186), 8-12 (n = 219), ≥ 12 mg/week (n = 97) decreased by 0.2 ± 7.3, 0.6 ± 8.6, and 4.5 ± 7.9 mL/min/1.73 m²/year, respectively (p < 0.0001). After adjustment for the confounding factors, MTX ≥ 12 mg/week was still correlated with a decrease in 1-year eGFR (beta-coefficient: - 2.5; 95% confidence interval, - 4.3 to - 0.6; p = 0.0089) in contrast to MTX 8-12 mg/week. Careful monitoring of renal function is required in patients with MTX ≥ 12 mg/week over the course of RA treatment regardless of disease duration.

Fact-finding survey on health literacy among Japanese predialysis chronic kidney disease patients: a multi-institutional cross-sectional study

BACKGROUND

Low health literacy (HL) has been associated with poor chronic disease management and adverse outcomes. However, reports on HL in predialysis chronic kidney disease (CKD) patients are limited in Japan.

METHODS

From August 2019 to February 2020, the European Health Literacy Survey (Japanese version) and a patient background survey (highest level of education, income, social activities, and exercise habit) were conducted on adult predialysis CKD patients. We compared clinical parameters in two groups according to the average HL score of a healthy Japanese population. In addition, a median value of 42 items was used as a cutoff for extracting CKD patient background factors associated with HL since HLS-EU-Q47 included five items related to physical activity and exercise.

RESULTS

Valid responses were received from 200 patients. Median general HL index was 25.2 points. The high-HL group (≥ 25.3 points) showed a low proportion of male (56.7% vs. 70.9%, p = 0.038), high social activities (69.1% vs. 48.5%, p = 0.003), and high exercise habit (36.1% vs. 13.6%, p < 0.001). In the multivariate analysis, social activity [OR (95% CI); 2.12 (1.16-3.89), p = 0.015] and exercise habit [OR (95% CI); 2.39 (1.16-4.90), p = 0.018] were extracted as the only significant variable.

CONCLUSIONS

HL in Japanese predialysis CKD patients was associated with high social activity and exercise habit.

Prevalences of hyperuricemia and electrolyte abnormalities in patients with chronic kidney disease in Japan: A nationwide, cross-sectional cohort study using data from the Japan Chronic Kidney Disease Database (J-CKD-DB)

BACKGROUND

The Japan Chronic Kidney Disease Database (J-CKD-DB) is a nationwide clinical database of patients with chronic kidney disease (CKD) based on electronic health records. The objective of this study was to assess the prevalences of hyperuricemia and electrolyte abnormalities in Japanese patients with CKD.

METHODS

In total, 35,508 adult outpatients with estimated glomerular filtration rates of 5-60 ml/min/1.73 m2 in seven university hospitals were included this analysis. The proportions of patients with CKD stages G3b, G4, and G5 were 23.5%, 7.6%, and 3.1%, respectively.

RESULTS

Logistic regression analysis showed that prevalence of hyperuricemia was associated with CKD stages G3b (adjusted odds ratio [95% confidence interval]: 2.12 [1.90-2.37]), G4 (4.57 [3.92-5.32]), and G5 (2.25 [1.80-2.80]). The respective prevalences of hyponatremia, hypercalcemia, hyperphosphatemia, and narrower difference between serum sodium and chloride concentrations were elevated in patients with CKD stages G3b, G4, and G5, compared with those prevalences in patients with CKD stage G3a. The prevalences of hyperkalemia were 8.3% and 11.6% in patients with CKD stages G4 and G5, respectively. In patients with CKD stage G5, the proportions of patients with optimal ranges of serum uric acid, potassium, corrected calcium, and phosphate were 49.6%, 73.5%, 81.9%, and 56.1%, respectively.

CONCLUSIONS

We determined the prevalences of hyperuricemia and electrolyte abnormalities in Japanese patients with CKD using data from a nationwide cohort study.

Febuxostat for Cerebral and CaRdiorenovascular Events PrEvEntion StuDy

Aims

To compare the occurrence of cerebral, cardiovascular, and renal events in patients with hyperuricaemia treated with febuxostat and those treated with conventional therapy with lifestyle modification.

Methods and results

This multicentre, prospective, randomized open-label, blinded endpoint study was done in 141 hospitals in Japan. A total of 1070 patients were included in the intention-to-treat population. Elderly patients with hyperuricaemia (serum uric acid >7.0 to ≤9.0 mg/dL) at risk for cerebral, cardiovascular, or renal disease, defined by the presence of hypertension, Type 2 diabetes, renal disease, or history of cerebral or cardiovascular disease, were randomized to febuxostat and non-febuxostat groups and were observed for 36 months. Cerebral, cardiovascular, and renal events and all deaths were defined as the primary composite event. The serum uric acid level at endpoint (withdrawal or completion of the study) in the febuxostat (n = 537) and non-febuxostat groups (n = 533) was 4.50 ± 1.52 and 6.76 ± 1.45 mg/dL, respectively (P < 0.001). The primary composite event rate was significantly lower in the febuxostat group than in non-febuxostat treatment [hazard ratio (HR) 0.750, 95% confidence interval (CI) 0.592–0.950; P = 0.017] and the most frequent event was renal impairment (febuxostat group: 16.2%, non-febuxostat group: 20.5%; HR 0.745, 95% CI 0.562–0.987; P = 0.041).

Conclusion

Febuxostat lowers uric acid and delays the progression of renal dysfunction.

Registration

ClinicalTrials.gov (NCT01984749).

Association between the size of healthcare facilities and the intensity of hypertension therapy: a cross-sectional comparison of prescription data from insurance claims data

Hypertension is a heterogeneous disease for which role sharing in treatment between specialized facilities and small clinics is needed for efficient healthcare provision. However, the Japanese healthcare system has a “free access” attribute; therefore, nobody can control treatment resource allocation. We aimed to describe the current situation of role sharing by comparing antihypertensive therapies among different types of medical facilities. We analyzed 1% sampled Japanese medical insurance claims data related to outpatient care as of October 2014. We divided the target patients into four groups according to the size of the facilities that issued the insurance claim for them. Among these groups, we compared the number of antihypertensive drugs and proportion of difficult-to-treat hypertensive cases and performed a stratified analysis. The proportion of patients with hypertension and diabetes mellitus receiving renin-angiotensin-aldosterone system inhibitors (RAASis) as the first-choice drug was also compared. We identified 3465, 1797, 2323, and 34,734 claims issued from large, medium-sized, small hospitals, and clinics, respectively. The mean number of hypertensive drugs was 1.96, 1.87, 1.81, and 1.69, respectively, and the proportion of difficult-to-treat hypertensive cases was 18.9, 17.0, 14.3, and 12.0%, respectively, with both showing significant differences. Stratified analysis showed similar results. The proportion of patients with hypertension and diabetes mellitus receiving RAASis as the first-choice drug was higher in large hospitals than in clinics. In conclusion, facility size is positively associated with the number of antihypertensive drugs and proportions of difficult-to-treat hypertensive cases. This finding describes the current role sharing situation of hypertension therapy in the Japanese healthcare system with a “free-access” attribute.

Clinical characteristics and in-hospital outcomes in patients aged 80 years or over with cardiac troponin-positive acute myocardial infarction -J-MINUET study

BACKGROUND

The prevalence of acute myocardial infarction (AMI) in elderly people is increasing worldwide. However, their characteristics and prognosis have been rarely investigated. This study aimed to investigate the characteristics and prognosis in elderly patients with cardiac troponin-positive AMI.

METHODS

Consecutive patients with AMI from the J-MINUET study were divided into the following 3 groups: patients aged less than 65 years, those aged between 65 and 79 years, and those aged 80 years or over. Their characteristics and in-hospital outcomes were compared.

RESULTS

Patients with AMI aged 80 years or over had the highest incidence of female gender, and the highest incidence of hypertension, chronic kidney disease, and cardiovascular disease, such as peripheral artery disease, atrial fibrillation, and stroke, whereas they had the lowest body mass index, and the lowest incidence of current smoker, diabetes mellitus, and dyslipidemia. Patients with AMI aged 80 years or over had significantly longer onset to door time and longer door to device time, and lower peak creatine kinase (CK). The incidence of ST-segment elevation myocardial infarction (STEMI) was the lowest in the AMI patients aged 80 years or over, but the patients had a higher incidence of in-hospital death and cardiac failure than the other two groups. In addition, the presentation with STEMI and non-ST-segment elevation myocardial infarction with CK elevation among patients aged 80 years or over showed the highest incidence of in-hospital death and cardiac failure.

CONCLUSIONS

J-MINUET showed different clinical characteristics between the aged and younger populations. The incidence of in-hospital death and cardiac failure in patients aged 80 years or over with AMI was poorer than their younger counterparts.

The pathogenesis of CKD complications; Attack of dysregulated iron and phosphate metabolism

Chronic kidney disease (CKD) patients have a tremendously higher risk of developing cardiovascular disease (CVD) and infection than the non-CKD population, which could be caused by intertwining actions of hyperphosphatemia and CKD associated misdistribution of iron. CVD is often associated with vascular calcification, which has been attributed to hyperphosphatemia, and could be initiated in mitochondria, inducing apoptosis, and accelerated by reactive oxygen species (ROS). The production of ROS is principally linked to intracellular ferrous iron. For infection, the virulence and pathogenicity of a pathogen is directly related to its capacity to acquire iron for proliferation and to escape or subvert the host's immune response. Iron administration for renal anemia can sometimes be overdosed, which could decrease host immune mechanisms through its direct effect on neutrophils, macrophages and T cell function. Hyperphosphatemia has been demonstrated to be associated with an increased incidence of infection. We hypothesized two possible mechanisms: 1) fibroblast growth factor-23 levels are increased in parallel with serum phosphate levels and directly impair leukocyte recruitment and host defense mechanisms, and 2) circulating non-transferrin-bound iron (NTBI) is increased due to decreased iron binding capacity of the carrier protein transferrin in high-phosphate conditions. From these observations, maintaining an adequate serum range of phosphate levels and minimizing intracellular iron accumulation could attenuate the development of CKD complications.

Potential mechanisms underlying the association between single nucleotide polymorphism (BRAP and ALDH2) and hypertension among elderly Japanese population

Minor allele frequency (MAF) of rs3782886 (BRAP) and rs671 (ALDH2) are reported to be inversely associated with blood pressure. Another study revealed that hematopoietic activity which is evaluated by reticulocytes could influenced on hypertension status partly by indicating activity of endothelial maintenance. Therefore, to evaluate the association between genetic factor and hypertension, influence of hematopoietic activity should be considered. A multi-faced analysis was performed in a simple general elderly population model (1,313 older Japanese aged 60–98 years). Participants were stratified by median values of reticulocytes (5.21 × 10⁴ cells/μL for men and 4.65 × 10⁴ cells/μL for women). Independent of known cardiovascular risk factors, MAF of rs3782886 and rs671 are significantly inversely associated with hypertension for participants with high hematopoietic activity (high reticulocytes level) (fully adjusted odds ratio (ORs) were 0.72 (0.55, 0.96) for rs3782886 and 0.72 (0.54, 0.96) for rs671) but not for low reticulocytes count (the corresponding values were 1.05 (0.79, 1.39) and 1.08 (0.81, 1.45), respectively). Hematopoietic activity evaluated by reticulocytes levels could influence on the association between single nucleotide polymorphism (rs3782886 and rs671) and hypertension. Those results were efficient tool to clarify the part of the mechanism that underlying the association between genetic factor and hypertension.

Association between Unhealthy Dietary Habits and Proteinuria Onset in a Japanese General Population: A Retrospective Cohort Study

The relationship between dietary habits and development of chronic kidney disease (CKD) is unclear. This retrospective cohort study was conducted to examine the association between unhealthy dietary habits and proteinuria onset, a key prognostic factor of CKD, among a Japanese general population aged ≥40 years. The risks of proteinuria onset were estimated based on the status of baseline unhealthy dietary habits (quick eating, late dinner, late evening snack, and skipping breakfast) compared with the status without these habits. A total of 26,764 subjects were included, with a mean follow-up period of 3.4 years. The most frequent unhealthy dietary habit was quick eating (29%), followed by late dinner (19%), late evening snack (16%), and skipping breakfast (9%). During the follow-up period, 10.6% of participants developed proteinuria. Late dinner and skipping breakfast showed an increased adjusted risk of proteinuria onset (hazard ratio (HR) 1.12, 95% confidence interval (CI) 1.02 to 1.22, and HR 1.15, 95% CI 1.01 to 1.31, respectively). Unhealthy dietary habits were not associated with changes in body mass index or waist-to-height ratio during the follow-up period. Our results suggest that late dinner and skipping breakfast are associated with higher risks for proteinuria onset.

Prevalence of chronic kidney disease in Bangladesh: a systematic review and meta-analysis

BACKGROUND

Worldwide, chronic kidney disease (CKD) is a major public health issue, with a leading cause of death and disability. The aim of our study to estimate the prevalence of CKD in the Bangladeshi population based on existing data of previous studies.

METHODS

In this systematic review and meta-analysis study, electronic search engines of PubMed, Google Scholar, Scopus, and the national journal databases were used to find relevant published articles until December 31, 2019. Based on predefined inclusion/exclusion criteria, nine studies were included, and RevMan V5.0 statistical software was used for meta-analysis.

RESULTS

The outcomes of the included studies (nine studies, a total of 225,206 participants) based on meta-analysis showed an overall prevalence of CKD in Bangladeshi people of 22.48%, which was higher than the global prevalence of CKD. The prevalence of CKD in females was higher with high heterogeneity (I² 90%) in contrast to male participants (25.32% vs. 20.31%).

CONCLUSION

Above all, this study revealed a higher rate of prevalence of CKD in Bangladeshi people. So, it needs more attention to concern public health policymakers and the government to control and reduce the high-risk of disability due to CKD.

Prevalence of anemia in patients with chronic kidney disease in Japan: A nationwide, cross-sectional cohort study using data from the Japan Chronic Kidney Disease Database (J-CKD-DB)

BACKGROUND

The Japan Chronic Kidney Disease Database (J-CKD-DB) is a nationwide clinical database of patients with chronic kidney disease (CKD) based on electronic health records. The objective of this study was to assess the prevalence of anemia and the utilization rate of erythropoiesis-stimulating agents (ESAs) in Japanese patients with CKD.

METHODS

In total, 31,082 adult outpatients with estimated glomerular filtration rates of 5-60 ml/min/1.73 m2 in seven university hospitals were included this analysis. The proportions of patients with CKD stages G3b, G4, and G5 were 23.5%, 7.6%, and 3.1%, respectively.

RESULTS

The mean (standard deviation) hemoglobin level of male patients was 13.6 (1.9) g/dl, which was significantly higher than the mean hemoglobin level of female patients (12.4 (1.6) g/dl). The mean (standard deviation) hemoglobin levels were 11.4 (2.1) g/dl in patients with CKD stage G4 and 11.2 (1.8) g/dl in patients with CKD stage G5. The prevalences of anemia were 40.1% in patients with CKD stage G4 and 60.3% in patients with CKD stage G5. Logistic regression analysis showed that diagnoses of CKD stage G3b (adjusted odds ratio [95% confidence interval]: 2.32 [2.09-2.58]), G4 (5.50 [4.80-6.31]), and G5 (9.75 [8.13-11.7]) were associated with increased prevalence of anemia. The utilization rates of ESAs were 7.9% in patients with CKD stage G4 and 22.4% in patients with CKD stage G5.

CONCLUSIONS

We determined the prevalence of anemia and utilization rate of ESAs in Japanese patients with CKD using data from a nationwide cohort study.

Decisive evidence corroborates a null relationship between MTHFR C677T and chronic kidney disease: A case-control study and a meta-analysis

BACKGROUND

Previous meta-analyses have explored the association between the C677T polymorphism of methyltetrahydrofolate reductase (MTHFR) and chronic kidney disease (CKD) but there were no studies with a decisive conclusion. Furthermore, the high heterogeneity among different populations is not yet interpreted.

OBJECTIVES

This study used trial sequential analysis (TSA) to evaluate whether the nowadays conclusion supported by current cumulative samples. We also applied case-weighted meta-regression to explore the potential gene-environment interactions.

METHODS

For the first stage of this study we conducted a case-control study involving 847 dialysis patients from 7 hemodialysis centers in Taipei during 2015 to 2018 and 755 normal controls from a health center in the Tri-Service General Hospital. The second stage combined the results from the first stage with previous studies. The previous studies were collected from PubMed, EMBASE, and Web of Science databases before January 2018.

RESULTS

From the case-control study, the T allele of MTHFR C677T appeared to have a protective effect on end-stage renal disease compared with the C allele [odds ratio (OR): 0.80, 95% CI (confidence interval) = 0.69-0.93]. However, the meta-analysis contradicted the results in Asian (OR = 1.12, 95% CI = 0.96-1.30). The same analysis was also applied in Caucasian and presented similar results from Asian (OR = 1.18, 95% CI = 0.98-1.42). The TSA showed our case-control study to be the decisive sample leading to a null association among Asian population. The high heterogeneity (I = 75%) could explain the contradictory results between the case-control study and the meta-analysis. However, further case-weighted meta-regression did not find any significant interaction between measured factors and MTHFR C677T on CKD.

CONCLUSIONS

High heterogeneities were found in both Caucasian and Asian, which caused the null relationship in meta-analysis while there were significant effects in individual studies. Future studies should further explore the high heterogeneity that might be hidden in unmeasured gene-environment interactions, to explain the diverse findings among different populations.

PPARG Pro12Ala Polymorphism with CKD in Asians: A Meta-Analysis Combined with a Case-Control Study-A Key for Reaching Null Association

BACKGROUND

So far, numerous meta-analyses have been published regarding the correlation between peroxisome proliferator-activated receptor gamma (PPARG) proline 12 alanine (Pro12Ala) gene polymorphism and chronic kidney disease (CKD); however, the results appear to be contradictory. Hence, this study is formulated with the objective of using existing meta-analysis data together with our research population to study the correlation between PPARG Pro12Ala gene polymorphism and CKD and evaluate whether an accurate result can be obtained.

METHODS

First, literature related to CKD and PPARG Pro12Ala available on the PubMed and EMBASE databases up to December 2016 was gathered from 20 publications. Then, the gathered results were combined with our case-control study of 1693 enrolled subjects and a trial sequential analysis (TSA) was performed to verify existing evidence and determine whether a firm conclusion can be drawn.

RESULTS

The TSA results showed that the cumulative sample size for the Asian sample was 6078 and was sufficient to support a definite result. The results of this study confirmed that there is no obvious correlation between PPARG Pro12Ala and CKD for Asians (OR = 0.82 (95% CI = 0.66-1.02), I² = 63.1%), but this was not confirmed for Caucasians. Furthermore, the case-control sample in our study was shown to be the key for reaching this conclusion.

CONCLUSIONS

The meta-analysis results of this study suggest no significant correlation between PPARG Pro12Ala gene polymorphism and CKD for Asians after adding our samples, but not for Caucasian.

Asymptomatic sinusitis as an origin of infection-related glomerulonephritis manifesting steroid-resistant nephrotic syndrome: A case report

RATIONALE

Infection is a major trigger or pathogenic origin in a substantial proportion of glomerulonephritis (GN) patients, typically manifesting infection-related GN (IRGN). Various microorganisms, infection sites, and clinical and histopathological features are involved in IRGN. Once an infectious origin is identified and successfully eradicated, nephrotic syndrome or kidney dysfunction is spontaneously resolved. However, if patients are asymptomatic and the origin is undetermined, the diagnosis and treatment of GN is challenging. This case presentation reported on an IRGN case manifesting steroid-resistant nephrotic syndrome associated with asymptomatic sinusitis as a pathogenic origin.

PATIENT CONCERNS

A 68-year-old male presented with severe kidney dysfunction and edema in both extremities.

DIAGNOSIS

The patient was clinically diagnosed with hypocomplementemic nephrotic syndrome and kidney dysfunction and histopathologically with diffuse proliferative GN and a focal pattern of membranoproliferative GN. The findings suggested that idiopathic membranoproliferative glomerulonephritis type I was more likely than IRGN, given a critical lack of apparent infection.

INTERVENTIONS

Combined intravenous methylprednisolone, oral prednisolone, and cyclosporin did not improve the patient's condition. Thus, IRGN associated with inapparent infectious origin was suspected. Repeated thorough and careful examinations including CT scan showed sinusitis in his left maxillary sinus. Moreover, reanalysis of kidney specimen revealed positive nephritis-associated plasmin receptor in glomeruli, a typical finding for IRGN, supporting a pathogenic significance of his sinusitis. Medical treatment was initiated with 200 mg oral clarithromycin daily.

OUTCOMES

Oral clarithromycin gradually improved proteinuria and hypocomplementemia and resulted in nephrotic syndrome remission in parallel with opacification resolution of sinuses shown on CT.

LESSONS

This case presentation showed that asymptomatic sinusitis is potentially a pathogenic IRGN origin. A gold standard therapy for idiopathic GN, corticosteroid could be damaging in uncontrolled or underdiagnosed infection. In asymptomatic patients, a thorough screening of infectious diseases, including sinusitis, together with a renal histological evaluation of glomerular nephritis-associated plasmin receptor deposition is also essential in treating a wide spectrum of GN.

Association between Non-Alcoholic Fatty Liver Disease and Chronic Kidney Disease: A Cross-Sectional Study

It is unclear whether the link between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD) is mediated by common risk factors. We aimed to elucidate the association between NAFLD and CKD using propensity score (PS)-matched analysis. We assessed 3725 Japanese individuals, excluding those with hepatitis B or C infection and men and women who consumed >30 and >20 g/day of alcohol, respectively. Of these, we enrolled 1097 Japanese subjects with NAFLD diagnosed by ultrasonography and 1097 PS-matched subjects without NAFLD. The prevalence of CKD was higher in subjects with NAFLD than in those without NAFLD before PS matching, but there was no significant difference between these groups in terms of CKD prevalence after PS matching. There was no difference in the prevalence of CKD between those with and without NAFLD in the subgroup analyses. Logistic regression analysis demonstrated that obesity, hypertension, and hyperuricemia were independent predictors of CKD, but NAFLD was not independently associated with CKD. In subjects with NAFLD, obesity, hypertension, and hyperuricemia were independent predictors of CKD. Thus, the link between NAFLD and CKD may be mediated by common risk factors. We recommend screening for CKD when patients with NAFLD have the aforementioned comorbidities.

Alteración de la función renal: prevalencia y factores asociados en pacientes de riesgo

Introducción: La enfermedad renal crónica (ERC) en sus primeras etapas no presenta manifestaciones clínicas y, por lo tanto, la mayoría de las personas solo se acercan a las unidades de salud cuando ya están en la fase terminal de la enfermedad, lo cual sigue siendo habitual en Brasil. Objetivo: Identificar la prevalencia de la tasa estimada de filtración glomerular (TFG) alterada y los factores asociados en usuarios del sistema de salud único que sufran de diabetes mellitus y/o hipertensión sistémica de alto riesgo de enfermedad cardiovascular. Materiales y métodos: Se realizó un estudio transversal con las historias clínicas de 331 usuarios del Centro Estatal de Atención Especializada ubicado en el centro oeste de Minas Gerais, Brasil entre septiembre de 2017 y junio de 2019. Se realizaron un análisis univariado descriptivo y una regresión logística multivariante. Resultados: Del total de participantes, 118 (35,6%) tenían la TFG alterada. Se identificó una asociación significativa entre la alteración de la TFG y la edad: los ancianos ≥ 60 años tenían 5,53 veces más posibilidades de tener la TFG alterada. Los participantes que utilizaron la polifarmacia tenían 2,64 veces más probabilidades de que se alterara la TFG. Discusión: En consonancia con estudios similares, se registró la falta de seguimiento del inicio y el desarrollo de la ERC en las primeras etapas, lo que implica un enfoque tardío y acciones limitadas para preservar las funciones renales. Conclusiones: Se identificó una alta prevalencia de TFG alterada (35,6%) sin registros en las tablas que pudieran conducir a un enfoque preventivo de la degeneración de la función renal. La edad avanzada y la polifarmacia se identificaron como variables independientes en la alteración de la función renal. Como citar este artículo: Castro, Tássia Lima Bernardino; Oliveira, Rayane Hellen; Sousa, João Antônio Gomides; Romano, Márcia Christina Caetano; Guedes,Guedes, João Victor Marques; Otoni, Alba. Função renal alterada: prevalência e fatores associados em pacientes de risco. Revista Cuidarte. 2020; 11(2): e1019. http://dx.doi.org/10.15649/cuidarte.1019

Evaluation of biochemical profile of Chronic Kidney Disease of uncertain etiology in Sri Lanka

Chronic Kidney Disease of uncertain etiology (CKDu) is an endemic, disease that mostly affects young agricultural workers in the rural dry zone of Sri Lanka. This study was designed to identify specific biochemical manifestations of CKDu cases. All (119) non-dialysis definite CKDu patients in Girandurukotte and Wilgamuwa were selected. Blood and urine samples were collected and measured biochemical parameters. All analyses were performed in IBM SPSS statistics version 23 (IBM Corp, USA). The median blood pressure was normal though nearly half of the patients (45.4%) who were in the advanced stages (Stage 3b, 4 and 5) of CKDu. Patients without a history of hypertension before the diagnosis of CKDu (100%) and minimal proteinuria (26%) are similar to the previous findings. Patients without a history of diabetes before the CKDu diagnosis had high percentages of diabetes (15.7%) and pre-diabetes (59.8%) and hence indicated the possibility of uremia induced impaired glucose intolerance in the rural areas of the country. There were 62.2% patients who had low vitamin D and only a minority had evidence of bone mineral diseases. Out of liver disease markers serum glutamic pyruvic transaminases (SGPT), serum glutamic oxaloacetic transaminases (SGOT), gamma-glutamyl transferase (GGT), and Lactic acid degydrogenase (LDH) had an inverse correlation with the advancement of the disease indicating subclinical liver disease. Osmolality in serum and urine showed a discrepancy despite > 50% of CKDu patients had increased their serum osmolality. The current study supports most of the previously described manifestations of CKDu. Moreover, some specific patterns have been identified which need to be validated in a larger group.

Diagnosis Patterns of CKD and Anemia in the Japanese Population

INTRODUCTION

Although early intervention for chronic kidney disease (CKD) and renal anemia are desirable, these conditions are often asymptomatic during their early stages and may be underdiagnosed.

METHODS

We retrospectively analyzed Japanese administrative claims data for general and hospital populations. The data period for the general and hospital data ranged from January 2011 to December 2016 and from April 2008 to July 2017, respectively. CKD stage was determined by estimated glomerular filtration rate (eGFR). Anemia was defined per Japanese guidelines using hemoglobin (Hb) values. The proportion of patients who had eGFR-defined stages G3-G5 CKD without a CKD diagnosis, and Hb-defined anemia without an anemia diagnosis or treatment records, was estimated.

RESULTS

Among 16,779 (general) and 68,161 (hospital) patients, a high proportion of G3 CKD patients did not have a CKD-related diagnosis (general: G3a, 95.0%; G3b, 68.4%; hospital: G3a, 89.2%; G3b, 67.9%); however, some patients were treated with antihypertensives. Among anemic patients, 75.7% (G3a) and 66.7% (G3b) of the general population, and 56.2% (G3a) and 47.5% (G3b) of the hospital population, did not have an anemia-related diagnosis or treatment. CKD and anemia were more likely to be diagnosed in patients with G4 and G5 CKD.

CONCLUSION

A high proportion of G3 CKD patients did not have a CKD-related diagnosis. Likewise, many anemic patients with G3 CKD did not have an anemia-related diagnosis. Despite the lack of a CKD-related diagnosis, some patients received appropriate treatment (e.g., antihypertensives). Further outreach to CKD and anemia patients at earlier stages may be warranted.

J-CKD-DB: a nationwide multicentre electronic health record-based chronic kidney disease database in Japan

The Japan Chronic Kidney Disease (CKD) Database (J-CKD-DB) is a large-scale, nation-wide registry based on electronic health record (EHR) data from participating university hospitals. Using a standardized exchangeable information storage, the J-CKD-DB succeeded to efficiently collect clinical data of CKD patients across hospitals despite their different EHR systems. CKD was defined as dipstick proteinuria ≥1+ and/or estimated glomerular filtration rate <60 mL/min/1.73 m² base on both out- and inpatient laboratory data. As an initial analysis, we analyzed 39,121 CKD outpatients (median age was 71 years, 54.7% were men, median eGFR was 51.3 mL/min/1.73 m²) and observed that the number of patients with a CKD stage G1, G2, G3a, G3b, G4 and G5 were 1,001 (2.6%), 2,612 (6.7%), 23,333 (59.6%), 8,357 (21.4%), 2,710 (6.9%) and 1,108 (2.8%), respectively. According to the KDIGO risk classification, there were 30.1% and 25.5% of male and female patients with CKD at very high-risk, respectively. As the information from every clinical encounter from those participating hospitals will be continuously updated with an anonymized patient ID, the J-CKD-DB will be a dynamic registry of Japanese CKD patients by expanding and linking with other existing databases and a platform for a number of cross-sectional and prospective analyses to answer important clinical questions in CKD care.

Randomized Clinical Trial on the Effect of Bardoxolone Methyl on GFR in Diabetic Kidney Disease Patients (TSUBAKI Study)

Introduction

Bardoxolone methyl significantly increases estimated glomerular filtration rate (eGFR) in patients with chronic kidney disease (CKD). However, the phase 3 study, Bardoxolone Methyl Evaluation in Patients with Chronic Kidney Disease and Type 2 Diabetes Mellitus: the Occurrence of Renal Events (BEACON), was terminated prematurely because bardoxolone methyl increased the risk for early-onset fluid overload in patients with identifiable risk factors for heart failure (elevated baseline B-type natriuretic peptide levels >200 pg/ml and prior history of hospitalization for heart failure). The Phase 2 Study of Bardoxolone Methyl in Patients with Chronic Kidney Disease and Type 2 Diabetes (TSUBAKI) study aimed to determine if patients without risk factors can mitigate the risk for fluid overload and whether changes in eGFR with bardoxolone methyl reflect true increases in GFR.

Methods

This phase 2, randomized, multicenter, double-blind, placebo-controlled study enrolled patients with type 2 diabetes and stage 3-4 CKD. Patients were randomized 1:1 to bardoxolone methyl (n = 41) or placebo (n = 41) (cohort G3), or 2:1 to bardoxolone methyl (n = 24) or placebo (n = 14) (cohort G4), administered orally once daily for 16 weeks using a dose-titration scheme. The primary efficacy endpoint was change from baseline in GFR measured by inulin clearance at week 16 in the cohort G3.

Results

A total of 40 patients were evaluated for the prespecified primary efficacy analysis. Mean change (95% confidence interval [CI]) from baseline in GFR was 5.95 (2.29 to 9.60) and -0.69 (-3.83 to 2.45) ml/min per 1.73 m² for patients randomized to bardoxolone methyl and placebo, respectively, with a significant intergroup difference of 6.64 ml/min per 1.73 m² (P = 0.008). Increases in the albumin/creatinine ratio were observed in the bardoxolone methyl group vs the placebo group. The most common adverse events (≥15% in either group) were viral upper respiratory tract infection, increased alanine aminotransferase, increased aspartate aminotransferase, increased γ-glutamyltransferase, and constipation. Peripheral edema was reported by 4 patients receiving bardoxolone methyl and by 1 patient receiving placebo; all events were mild and self-limiting. No patient died or experienced heart failure. The study discontinuation rate was higher in the bardoxolone methyl group (cohort G3, n = 8; cohort G4, n = 7) than the placebo group (cohort G3, n = 1; cohort G4, n = 0).

Conclusion

Bardoxolone methyl significantly increased measured GFR, and further investigation is ongoing to evaluate whether it provides clinical benefit without major safety concerns in selected patients with CKD.

Undiagnosed chronic kidney disease and its associated risk factors in an agricultural Moroccan adult's population

INTRODUCTION

Chronic kidney disease is among the major non-communicable diseases with increasing prevalence. This study aimed to estimate the prevalence of chronic kidney disease and its associated risk factors among Moroccan population sample from Sidi Bennour province.

METHODS

An observational, descriptive and analytical study was conducted in an agricultural community of Morocco. A sample of 182 subjects aged 18 or older, randomly selected from the province health care centers. The information on the participants was collected using a structured questionnaire, blood samples were collected and the serum creatinine was determined. Subsequent glomerular filtration rate (eGFR) was estimated by the modification of diet in renal disease formula and the chronic kidney disease was defined by an eGFR<60 mL/min/1.73 m².

RESULTS

The participants mean age was 53.58±12.06 years, with a sex ratio of 0.30 and the prevalence of chronic kidney disease was 4.4%. The risk factors associated with chronic kidney disease were age, hypertension, and nephrotoxic treatment, that are significantly correlated with renal impairment (P=0.006 for age, P=0.008 for hypertension and P=0.001 for nephrotoxic medication used respectively).

CONCLUSIONS

The study data show that chronic kidney disease should be of important consideration in any strategy to address non-communicable diseases and associated risk factors.

Study Design and Baseline Profiles of Participants in the Uonuma CKD Cohort Study in Niigata, Japan

Background

Evidence for primary prevention of chronic kidney disease (CKD) is insufficient. The population-based prospective Uonuma CKD cohort study aims to explore associations of lifestyle and other risk factors with CKD. We report here the study design and baseline profiles.

Methods

All 67,322 residents aged ≥40 years in Minamiuonuma City, Uonuma City, and Yuzawa Town, Niigata Prefecture, Japan and 11,406 participants who attended local health-check examinations were targeted for baseline questionnaire and biochemical sampling, respectively. Information was gathered from 43,217 (64.2%) questionnaires and 8,052 (70.6%) biochemical samples; 6,945 participants consented to both questionnaire and biochemical sampling at baseline, conducted between fiscal years 2012 and 2015. Participants provided information regarding sociodemographic, lifestyle, and self-reported outcomes. Urine albumin-to-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR) were measured. The primary outcome is CKD based on self-report and biochemical/clinical diagnosis.

Results

Mean age of questionnaire respondents was 63.3 (standard deviation [SD], 12.5) years for men and 64.3 (SD, 13.3) years for women. Among participants who submitted urine samples, median ACR was 10.0 (interquartile range [IQR], 5.0–24.0) mg/g for men and 13.0 (IQR, 7.7–27.0) mg/g for women, and median eGFR was 73.6 mL/min/1.73 m² (IQR, 63.5–84.5) for men and 73.5 mL/min/1.73 m² (IQR, 64.4–83.5) for women. ACR 30 mg/g or more was found in 1,741 participants (21.7%) and eGFR <60 mL/min/1.73 m² in 1,361 participants (16.9%).

Conclusion

The Uonuma CKD cohort study was established to investigate the impact of lifestyle on CKD development and to provide data for preventing the onset and progression of CKD.

Cerebral Microbleeds and Chronic Kidney Disease in Acute Ischemic Stroke Patients with Atrial Fibrillation

BACKGROUND

Cerebral microbleeds (CMBs) are associated with the risk of intracerebral hemorrhage in stroke patients with atrial fibrillation (AF). We investigated the association between CMBs and chronic kidney disease (CKD) in patients with acute ischemic stroke and AF.

METHODS

We retrospectively examined consecutive patients with acute ischemic stroke and AF who underwent brain gradient-echo T2*-weighted magnetic resonance imaging. The number and distribution (lobar, deep or infratentorial, and mixed) of CMBs were assessed. Kidney function was assessed according to the estimated glomerular filtration rate (eGFR), which was calculated using a modified version of the Modification of Diet in Renal Disease equation.

RESULTS

Of the 357 included patients, 105 (29.4%) had CMBs. CKD (eGFR < 60 mL/min/1.73 m²) was found in 131 (36.7%) patients. Patients with CKD showed a higher prevalence of any form of CMB (41.2% versus 22.6%, P < .001), deep or infratentorial CMBs (19.9% versus 9.3%, P < .01), and mixed CMBs (14.5% versus 5.3%, P < .01) than those without CKD. After adjusting for age and other confounding factors, CKD was found to be independently associated with the presence of any form of CMB (odds ratio 1.89, P = .02) and mixed CMBs (odds ratio 3.10, P < .01). Moreover, moderate to severe CKD (eGFR < 45 mL/min/1.73 m²) was independently associated with the presence of multiple CMBs (odds ratio 2.31, P = .04).

CONCLUSIONS

CMBs and CKD are common in acute ischemic stroke patients with AF, and CKD may be a risk factor for CMBs. Further longitudinal studies are needed to evaluate whether maintaining kidney function can prevent the development of CMBs.

Association among chronic kidney disease, airflow limitation, and mortality in a community-based population: The Yamagata (Takahata) study

Chronic kidney disease (CKD) and chronic obstructive pulmonary disease (COPD) are known risk factors for mortality. In this study, we examined the overlap of CKD and airflow limitation (AFL) that characterises COPD and its effect on 10-year mortality in a community-based population. This study included 1,233 health check-up participants (mean age, 63.7 years; 46.7% men). We defined serum creatinine-based CKD (CKDcr) and serum cystatin C-based CKD (CKDcys) as glomerular filtration rate <60 mL/min/1.73 m², estimated using serum creatinine or cystatin C, and/or dipstick proteinuria ≥1+. AFL was defined as forced expiratory volume in 1 s to forced vital capacity ratio <70% on spirometry. Compared with subjects without AFL, those with AFL showed a significantly higher prevalence of CKDcys but not of CKDcr. Cox proportional hazard analysis adjusted for confounders showed that the hazard ratio (95% confidence interval) for all-cause mortality was 1.45 (0.77–2.63) in subjects with CKDcys alone, 1.29 (0.60–2.54) in those with AFL alone, and 2.94 (1.33–6.12) in those with both CKDcys and AFL, with subjects without both AFL and CKD as the reference. This study showed that AFL and CKDcys are strongly associated and that their overlap is a significant risk factor for mortality in community-based populations.

Circulating CD34+ cells and active arterial wall thickening among elderly men: A prospective study

Age-related physical changes, such as low-grade inflammation and increased oxidative stress, induce endothelial repair and cause active arterial wall thickening by stimulating the production of CD34+ cells (the principal mediators of atherosclerosis). Despite this, aggressive endothelial repair (progressing atherosclerosis) might cause a wasting reduction in CD34+ cells, which could result in a lower capacity of endothelial repair and hypertension. As yet, no prospective study has clarified the association of circulating CD34+ cells with active arterial wall thickening. We conducted a prospective study of 363 men aged 60-69 years who participated in a general health check-up at least twice from 2014-2017. The circulating CD34+ cell count was significantly positively associated with active arterial wall thickening among subjects without hypertension (n = 236), but not among subjects with hypertension (n = 127). The fully adjusted odds ratios (ORs) of active arterial wall thickening for the logarithmic circulating CD34+ cell count were 1.83 (1.19, 2.84) and 0.69 (0.36, 1.32) for subjects without and with hypertension, respectively. Circulating CD34+ cells are positively associated with active arterial wall thickening in subjects without hypertension. This study demonstrates a means to clarify the mechanisms of endothelial repair in elderly subjects.

Kidney function, blood pressure and proteinuria were associated with pregnancy outcomes of pregnant women with chronic kidney disease: a single-center, retrospective study in the Asian population

BACKGROUND

Studies among pregnant Asian women with chronic kidney disease (CKD) have not been widely performed; therefore, clinical criteria for these patients have not been well established.

METHODS

We conducted a retrospective study among pregnant women with CKD who received prenatal care at our institution for 8 consecutive years. Primary outcome was the development of severe adverse events (SAEs). We analyzed correlations between primary outcome and CKD parameters [age, body mass index (BMI), estimated glomerular filtration rate (eGFR), urinary protein-creatinine ratio (UP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and not normal blood pressure (non-NBP)] at the time of referral. Secondary outcomes were low birth weight (LBW), preterm delivery (PreD), and small for gestational age (SGA). We divided into two categories, CKD stage G1, and G2 or higher according to eGFR, and proteinuria negative and proteinuria positive according to UP, respectively.

RESULTS

We observed 89 pregnancies. SAE was observed in 28 pregnancies. In live birth cases, there were 28 PreD, 28 LBW and 13 SGA. Major SAEs included preeclampsia, superimposed preeclampsia, unscheduled cesarean section, neonatal intensive care unit admission, and fetal death. Stepwise logistic regression analysis selected eGFR (OR = 0.847, p = 0.026), SBP (OR = 1.897, p = 0.006) and proteinuria positive (OR = 2.96, p = 0.046) as the significant predictors of SAEs. There were no significant differences among the baseline characteristics stratified by SGA.

CONCLUSIONS

This is the first study to report pregnancy outcomes among Japanese non-disease-oriented patients with CKD. In Asians, especially in the Japanese population, kidney function, blood pressure and proteinuria might affect pregnancy outcomes.

Insulin-Like Growth Factor-1 (IGF-1) and Reduced Tongue Pressure in Relation to Atherosclerosis Among Community-Dwelling Elderly Japanese Men: A Cross-Sectional Study

Even though higher serum insulin-like growth factor-1 (IGF-1) levels have a positive effect on preventing reduction in muscle strength, a U-shaped association between IGF-1 and mortality has been reported. Since a recent experimental study revealed that IGF-1 is associated with atherosclerotic lesion formation, the inflammatory status of atherosclerosis could act as a confounding factor on the association between IGF-1 levels and reduced muscle strength. This study aimed to clarify the atherosclerosis-specific association between IGF-1 levels and reduced muscle strength. We conducted a cross-sectional study of 410 elderly men aged 60-89 years. Since a reduction in maximum voluntary tongue pressure against the palate (MTP) is reportedly associated with sarcopenia, we evaluated muscle strength by using MTP and defined reduced MTP as the lowest tertiles of the study population. Among study population, 295 showed no atherosclerosis (carotid intima-media thickness < 1.1 mm). Even though a significant inverse association between IGF-1 and reduced MTP was observed for subjects without atherosclerosis, no such association was detected for subjects with atherosclerosis. The known cardiovascular risk-factor adjusted odds ratio (OR) of a one-standard deviation (SD) increment (28.1 ng/mL) of IGF-1 for reduced MTP was 0.69 (0.51, 0.95) for subjects without atherosclerosis and 1.93 (1.05, 3.52) for subjects with atherosclerosis. IGF-1 was found to be inversely associated with a reduced MTP among elderly men without atherosclerosis but not among those with atherosclerosis. Atherosclerosis can thus act as a powerful confounding factor on the association between IGF-1 levels and a reduced MTP.

Global, regional, and national burden of chronic kidney disease, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Health system planning requires careful assessment of chronic kidney disease (CKD) epidemiology, but data for morbidity and mortality of this disease are scarce or non-existent in many countries. We estimated the global, regional, and national burden of CKD, as well as the burden of cardiovascular disease and gout attributable to impaired kidney function, for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017. We use the term CKD to refer to the morbidity and mortality that can be directly attributed to all stages of CKD, and we use the term impaired kidney function to refer to the additional risk of CKD from cardiovascular disease and gout.

METHODS

The main data sources we used were published literature, vital registration systems, end-stage kidney disease registries, and household surveys. Estimates of CKD burden were produced using a Cause of Death Ensemble model and a Bayesian meta-regression analytical tool, and included incidence, prevalence, years lived with disability, mortality, years of life lost, and disability-adjusted life-years (DALYs). A comparative risk assessment approach was used to estimate the proportion of cardiovascular diseases and gout burden attributable to impaired kidney function.

FINDINGS

Globally, in 2017, 1·2 million (95% uncertainty interval [UI] 1·2 to 1·3) people died from CKD. The global all-age mortality rate from CKD increased 41·5% (95% UI 35·2 to 46·5) between 1990 and 2017, although there was no significant change in the age-standardised mortality rate (2·8%, -1·5 to 6·3). In 2017, 697·5 million (95% UI 649·2 to 752·0) cases of all-stage CKD were recorded, for a global prevalence of 9·1% (8·5 to 9·8). The global all-age prevalence of CKD increased 29·3% (95% UI 26·4 to 32·6) since 1990, whereas the age-standardised prevalence remained stable (1·2%, -1·1 to 3·5). CKD resulted in 35·8 million (95% UI 33·7 to 38·0) DALYs in 2017, with diabetic nephropathy accounting for almost a third of DALYs. Most of the burden of CKD was concentrated in the three lowest quintiles of Socio-demographic Index (SDI). In several regions, particularly Oceania, sub-Saharan Africa, and Latin America, the burden of CKD was much higher than expected for the level of development, whereas the disease burden in western, eastern, and central sub-Saharan Africa, east Asia, south Asia, central and eastern Europe, Australasia, and western Europe was lower than expected. 1·4 million (95% UI 1·2 to 1·6) cardiovascular disease-related deaths and 25·3 million (22·2 to 28·9) cardiovascular disease DALYs were attributable to impaired kidney function.

INTERPRETATION

Kidney disease has a major effect on global health, both as a direct cause of global morbidity and mortality and as an important risk factor for cardiovascular disease. CKD is largely preventable and treatable and deserves greater attention in global health policy decision making, particularly in locations with low and middle SDI.

FUNDING

Bill & Melinda Gates Foundation.

Relationship between Serum Vitamin D and Leg Strength in Older Adults with Pre-Dialysis Chronic Kidney Disease: A Preliminary Study

Active vitamin D (calcitriol, or 1.25 (OH) 2 D) is associated with muscle weakness, falls, and fracture in community-dwelling older people. This study aimed to investigate the relationship between a serum active vitamin D level and lower extremity muscle strength in elderly patients with pre-dialysis chronic kidney disease (CKD). This cross-sectional study included 231 patients with CKD treated conservatively as outpatients. We analyzed patient background factors, including age, sex, body mass index (BMI), intact parathyroid hormone (PTH), phosphorus, calcium, albumin, serum calcitriol level as an indicator of active vitamin D, and estimated glomerular filtration rate (eGFR) collected from medical records. As an index of lower extremity muscle strength, the isometric knee extension muscle strength-to-weight ratio (kgf/kg) was calculated. The mean patient age was 75.9 ± 6.1 years (68.8% male), and the BMI was 24.1 ± 3.8 kg/m². A significant correlation was observed between knee extensor muscle strength and serum calcitriol level (r = 0.32, p < 0.01), age (r = -0.30, p < 0.01), BMI (r = -0.31, p < 0.01), intact PTH (r = -0.22, p < 0.01), phosphorus (r = -0.29, p < 0.01), albumin (r = -0.28, p < 0.01), and eGFR (r = 0.25, p < 0.01). Multiple regression analysis showed calcitriol to be significantly associated with knee extensor muscle strength (β: 0.14, 95% confidence interval: 0-0.002, p = 0.04) after adjustment for covariates. These results suggest that the serum active vitamin D level is associated with lower extremity muscle strength in older adults with pre-dialysis CKD. It is necessary to verify whether vitamin D supplementation increases lower extremity muscle strength in pre-dialysis CKD patients.

Renal status in elderly patients with type 2 diabetes

BACKGROUND

In Japan, there has been a remarkable increase in the incidence of type 2 diabetes in elderly patients. This study aimed to clarify the renal status in elderly patients with type 2 diabetes.

PARTICIPANTS AND METHODS

There were 978 patients with type 2 diabetes who were classified into three groups: Group 1 (aged < 65 years of age), Group 2 (65-74 years of age), and Group 3 (≥ 75 years of age). Estimated glomerular filtration rate (eGFR) and urinary albumin level were measured. Moreover, the frequencies of each stage of chronic kidney disease for each group were determined, and differences among the three groups were analyzed.

RESULTS

The mean eGFR in Group 3 was 63.2 ± 19.1 mL/min/1.73 m2, which was lower than those in Group 1 (83.3 ± 22.8 mL/min/1.73 m2) and Group 2 (72.0 ± 19.4 mL/min/1.73 m2). The percentage of low eGFR (< 60 mL/min/1.73 m2) with normo- and microalbuminuria in Group 3 was 31.9%, which was higher than the percentages observed in Group 1 (7.1%) or Group 2 (16.1%). Diabetic macroangiopathy was frequently observed in these patients. The frequency of low eGFR with proteinuria was 10.2%. In this group, diabetic micro- and macroangiopathies were frequently noted.

CONCLUSION

In elderly patients with type 2 diabetes, renal dysfunction is characterized by low eGFR with normo- and microalbuminuria. In this group, macroangiopathy was more common than microangiopathy. The elderly patients with diabetes with low eGFR with proteinuria frequently had micro- and macroangiopathies.

Association between Oral Health Status and Diabetic Nephropathy-Related Indices in Japanese Middle-Aged Men

Oral health status is known to be associated with lifestyle-related diseases such as diabetes and chronic kidney disease. In Japan, around 40% of hemodialysis cases are patients with diabetic nephropathy. The aim of this study was to clarify the association between oral health status and diabetic nephropathy-related indices in Japanese middle-aged men. Sixty-six men (age range: 55-64 years) with ≥20 remaining teeth and who received public medical checkups and oral examinations were enrolled. We examined correlations of age, body mass index, HbA1c, HDL-C, LDL-C, neutral fat, serum creatinine, and the estimated glomerular filtration rate (eGFR) with the number of remaining teeth or the community periodontal index (CPI) score (periodontal pocket < 4 mm: 0, 4-6 mm: 1, ≥6 mm: 2). A positive correlation between the CPI score and serum creatinine and a negative correlation between CPI score and eGFR (Spearman's rank correlation coefficient, r = 0.459, p < 0.01, and r = -0.460, p < 0.01, respectively) were observed. The mean eGFR in the CPI score 0 group was significantly higher than that in the CPI score 1/2 group (82.6 vs. 70.7, Student's t-test, p < 0.01). Logistic regression analysis using eGFR as a dependent variable and age, CPI score, body mass index, HbA1c, and neutral fat as independent variables suggested that low eGFR (<60) could be attributed to CPI score (OR = 3.169, 95% CI: 1.031-9.742, p = 0.044). These results suggest a possible association between periodontal status and renal function in Japanese middle-aged men. Periodontal condition is controlled by oral prophylaxis, and periodontal disease and chronic kidney disease have some common risk factors. Thus, periodontal management can contribute to the prevention of severe chronic kidney disease.

Higher NAFLD fibrosis score is associated with impaired eGFR

BACKGROUND/PURPOSE

Chronic kidney disease (CKD) has become a worldwide health problem, leading to high morbidity and mortality, and non-alcoholic fatty liver disease (NAFLD) is considered a risk factor for CKD. The aim of this study was to explore the relationship between NAFLD fibrosis score (NFS) and the estimated glomerular filtration rate (eGFR), and identify possible risk factors related to the NFS among Taiwanese subjects.

METHODS

Subjects were enrolled from the database of the Department of Preventive Medicine of Kaohsiung Municipal Hsiao-Kang Hospital. The eGFR was calculated according to the Taiwanese Modification of Diet in Renal Disease (TMDRD) equation, and the NFS was employed to evaluate the fibrotic level.

RESULTS

In total, 11,376 subjects were enrolled in this study, with a mean age of 52.0 ± 6.81 years, including 4529 (39.8%) males. A fasting sugar level ≥100 mg/dL (OR = 1.70, 95% CI = 1.52-1.87) and an abnormal waist circumference (OR = 1.81, 95% CI = 1.65-1.99) were significant factors associated with NFS (p < 0.05). Trends of a decreasing TMDRD score and an increasing NFS with increasing age were noted (p < 0.05). The NFS was significantly negatively correlated with the TMDRD score (standard coefficients: -0.067, p < 0.001).

CONCLUSION

A higher NFS is associated with an impaired eGFR in Taiwanese subjects. Controlling risk factors, especially fasting sugar level and waist circumference, may be useful in preventing NFS deterioration, which is negatively correlated with the eGFR.

Trajectories of kidney function and associated factors among community-dwelling older Japanese: a 16-year longitudinal study

BACKGROUND

No study has reported trajectories of kidney function in later life. This long-term prospective study attempted to classify trajectories of estimated glomerular filtration rate (eGFR) and identify factors associated with these trajectories.

METHODS

We collected data from annual geriatric health checkups conducted during 2002-2017 in Kusatsu Town, Gunma Prefecture, Japan. The participants were 1990 adults aged 65-90 years (mean [SD] age, 71.0 [5.7] years; 57.0% women), and the total number of observations was 9291. Data were analyzed with a group-based semiparametric mixture model and age-adjusted univariable cumulative logit models.

RESULTS

Trajectory of kidney function, as determined by eGFR, was classified as low, middle, and high (4.8%, 38.9%, and 56.3% of men, respectively, and 5.2%, 31.5%, and 63.3% of women). Among men and women in the low trajectory group, chronic kidney disease (CKD) stage worsened from stage G3a (51.8 ml/min/1.73 m² in men and 53.6 in women) at age 65 years to stage G4 (28.0 ml/min/1.73 m² in men and 28.5 in women) by age 85 years. A history of hypertension (men and women) and heart disease (men) were more likely in the low trajectory group than in the middle and high trajectory groups.

CONCLUSIONS

About 5% of community-dwelling older adults had an eGFR < 30 later in life. Our findings suggest that those with stage G3a CKD at age 65 years should be managed intensively, to control risk factors for CKD progression.

Blood pressure control in chronic kidney disease according to underlying renal disease: the Fukushima CKD cohort

BACKGROUND

Inadequate blood pressure control is one of the important causes of chronic kidney disease (CKD), but only a limited number of reports have examined blood pressure control in Japanese patients with pre-dialysis CKD. Differences in blood pressure control due to underlying renal disease in pre-dialysis patients with CKD were investigated in the present study using the baseline data of the Fukushima CKD cohort study.

METHODS

The study involved 1351 CKD patients, classified by underlying disease of primary renal disease, hypertensive nephropathy, diabetic nephropathy, other nephropathies, or unknown. Target blood pressure of CKD patients was defined as < 130/80 mmHg in patients under 75 years old with diabetes and/or proteinuria, and < 140/90 mmHg in other patients.

RESULTS

The achievement rate of target systolic blood pressure was lower in the diabetic and hypertensive nephropathy groups than in the primary renal disease group (33.3%, 46.0% vs. 68.1%, p < 0.001). However, the number of antihypertensive medications increased in the diabetic and hypertensive nephropathy groups compared to the primary renal disease group (2.16, 2.04 vs. 1.55, p < 0.001). Inadequate blood pressure control was independently related to the underlying renal disease, with a significant difference between diabetic nephropathy and primary renal disease (odds ratio 3.19; 95% confidence interval, 2.16-4.69; p < 0.001).

CONCLUSION

This study showed that blood pressure control differs by the underlying renal disease. Blood pressure control was poor especially in diabetic nephropathy despite multidrug combination antihypertensive treatment. It is necessary to verify whether strict blood pressure control improves patients' prognosis in diabetic nephropathy.

Circulating microRNAs (miR-126, miR-197, and miR-223) are associated with chronic kidney disease among elderly survivors of the Great East Japan Earthquake

Background

A recent study has reported that incidence of chronic kidney disease (CKD) is higher in evacuees, but the molecular mechanism still remains unclear. One plausible hypothesis is a change in vascular function following to psychological distress. In order to assess molecular mechanisms underlying this association, we examined whether cardiovascular disease (CVD)-associated miRNAs (miR-126, miR-197, and miR-223) were associated with CKD among Japanese elderly survivors after an earthquake.

Methods

We analyzed 1385 individuals (670 men and 715 women) who participated in a post-disaster health check-up after the Great East Japan Earthquake, which occurred in 2011. The check-up involved collection of information about lifestyle, clinical history, the degree of housing damage, and baseline measurement of the estimated glomerular filtration rate. Expression levels of miRNAs were determined using real-time polymerase chain reaction. Estimated glomerular filtration rate (eGFR) was calculated using sex, age, and serum creatinine. CKD was defined as eGFR < 60 ml/min/1.73m². The multivariable regression analyses were performed to examine the associations between CVD-associated miRNAs and CKD after adjusting potential confounders.

Results

Mean age (standard deviation) of participants with normal kidney function and CKD was 62.7 (10.6) and 71.9 (8.1) years, respectively. Expression levels of these miRNAs in participants with CKD were significantly lower than normal kidney function (all p < 0.001). Even after adjusting for lifestyle, clinical profiles, and psychological distress, significant associations between three miRNAs and CKD still remained. A significant linear association between the cumulative score of these miRNAs and CKD was found (p = 0.04).

Conclusions

This cross-sectional study suggested that CVD-associated miRNAs were an important factor of CKD in an elderly Japanese population after earthquake. Future studies need to examine this association in longitudinal dataset.

Waist height ratio predicts chronic kidney disease: a systematic review and meta-analysis, 1998-2019

BACKGROUND

The incidence of chronic kidney disease (CKD) increases each year, and obesity is an important risk factor for CKD. The main anthropometric indicators currently reflecting obesity are body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR), but the rationality and merits of various indicators vary. This article aims to find whether the WHtR is a more suitable physical measurement that can predict CKD.

METHODS

Pubmed, embase, the cochrane library, and web of science were systematically searched for articles published between 1998 and 2019 screening CKD through physical indicators. Two reviewers independently screened the literature according to the inclusion and exclusion criteria, extracted the data, and evaluated the quality of the methodology included in the study. Meta-analysis used the Stata 12.0 software.

RESULTS

Nine studies were included, with a total of 202,283 subjects. Meta-analysis showed that according to the analysis of different genders in 6 studies, regardless of sex, WHtR was the area with the largest area under the curve (AUC). Except WHtR and visceral fat index (VFI) in women which showed no statistical difference, WHtR and other indicators were statistically different. In three studies without gender-based stratification, the area under the curve AUC for WHtR remained the largest, but only the difference between WHtR and BMI was statistically significant. When the Chinese population was considered as a subgroup, the area under the curve AUC for WHtR was the largest. Except for WHtR and VFI which showed no statistical difference in women, there was a statistically significant difference between WHtR and other indicators in men and women.

CONCLUSION

WHtR could be better prediction for CKD relative to other physical measurements. It also requires higher-quality prospective studies to verify the clinical application of WHtR.

Nudging patients with chronic kidney disease at screening to visit physicians: A protocol of a pragmatic randomized controlled trial

BACKGROUND/AIMS

Strategies for an effective intervention after chronic kidney disease (CKD) screening have not been well examined. We describe the rationale and design of a protocol of a pragmatic randomized controlled trial (RCT) to test the effect of a behavioral intervention using the nudge approach in behavioral economics on CKD patients' visiting behaviors to physicians and change in their kidney function after CKD screening.

METHODS

The RCT will include CKD patients (N = 4500) detected at screening (estimated glomerular filtration rate [eGFR] <60 mL/min/1.74 m2 or urine protein ≥1+), aged 40-63 years. The two intervention groups will receive a "usual letter" and "nudge-based letter," while the control group will only receive a conventional follow-up. Our primary outcome is proportion of patients' visiting physicians for 6 months after the intervention; the secondary outcome is change in the eGFR at 2 years after the intervention.

RESULTS

We developed an efficient intervention program after CKD screening and designed the pragmatic RCT to assess its effectiveness in the real world. Our trial is unique in that it investigates the effect of the nudge approach in behavioral economics. By the end of 2018, we have enrolled 1,692 participants, and randomized 677 participants into the usual letter group, 677 participants into the nudge-based letter group, and 338 participants into the control group. We have confirmed that health checkup data could identify a large number of eligible participants.

CONCLUSION

The trial's results will contribute to filling in the gap between screening and subsequent medical interventions for preventing CKD progression.