Cigarette smoking and progression of kidney dysfunction: a longitudinal cohort study.

INTRODUCTION: Cigarette smoking is one of the most important life-modifiable risk factors for CVD events. The effect on CKD progression caused by smoking remained uncertain, while the effect on CVD had been established. METHOD: The study population included participants from the specific health check and specific health guidance, an annual health check-up for all inhabitants of Japan who were aged between 40 and 74 years. 149,260 subjects (male, 37.1%; female, 62.9%) were included in this analysis. RESULTS: The relationship between smoking status along with new-onset proteinuria and eGFR deterioration more than 15 mL/min/1.73 m2 was examined. Median observation periods were 1427 days [738, 1813] in males and 1437 days [729, 1816] in females. In male participants, the strongest factor upon kidney dysfunction was new-onset proteinuria (1.41 [1.31 1.51], P < 0.001). The second strongest factor on kidney deterioration was smoking (1.24 [1.16 1.31], P < 0.001). In female participants, strongest factor upon kidney dysfunction was smoking (1.27 [1.16-1.39], P < 0.001). The second strongest factor on kidney deterioration was new-onset proteinuria (1.26 [1.17 1.36], P < 0.001). To reveal the relationship of effects from new-onset proteinuria and smoking on the kidney function, the participants were divided into four groups with and without new-onset proteinuria and smoking. The group with both proteinuria and smoking had significantly worst renal prognosis (P for trend < 0.001). CONCLUSION: Large longitudinal observation study revealed smoking has an evil effect on the progression of CKD. This evil effect could be observed in CKD patients with proteinuria as well as in general population without new-onset proteinuria.

Predicting CKD progression using time-series clustering and light gradient boosting machines.

Predicting the transition of kidney function in chronic kidney disease is difficult as specific symptoms are lacking and often overlooked, and progress occurs due to complicating factors. In this study, we applied time-series cluster analysis and a light gradient boosting machine to predict the trajectories of kidney function in non-dialysis dependent chronic kidney disease patients with baseline estimated glomerular filtration rate (GFR) ≥ 45 mL/min/1.73 m2. Based on 5-year changes in estimated GFR, participants were stratified into groups with similar trajectories by cluster analysis. Next, we applied the light gradient boosting machine algorithm and Shapley addictive explanation to develop a prediction model for clusters and identify important parameters for prediction. Data from 780 participants were available for analysis. Participants were classified into five classes (Class 1: n = 78, mean [± standard deviation] estimated GFR 100 ± 19.3 mL/min/1.73 m2; Class 2: n = 176, 76.0 ± 9.3 mL/min/1.73 m2; Class 3: n = 191, 59.8 ± 5.9 mL/min/1.73 m2; Class 4: n = 261, 52.7 ± 4.6 mL/min/1.73 m2; and Class 5: n = 74, 53.5 ± 12.0 mL/min/1.73 m2). Declines in estimated GFR were 8.9% in Class 1, 12.2% in Class 2, 4.9% in Class 3, 12.0% in Class 4, and 45.1% in Class 5 during the 5-year period. The accuracy of prediction was 0.675, and the top three most important Shapley addictive explanation values were 1.61 for baseline estimated GFR, 0.12 for hemoglobin, and 0.11 for body mass index. The estimated GFR transition of patients with preserved chronic kidney disease mostly depended on baseline estimated GFR, and the borderline for estimated GFR trajectory was nearly 50 mL/min/1.73 m2.

Association between vascular endothelial dysfunction and stroke incidence in the general Japanese population: Results from the tohoku medical megabank community-based cohort study.

Background: Flow-mediated dilation (FMD) measures vascular endothelial function by evaluating the vasodilatory response of blood vessels to increased blood flow. Nevertheless, the association between FMD and stroke incidence in a general population remains unclear. This study investigated the association between vascular endothelial function and stroke incidence in the general Japanese population. Methods: Based on cohort data from the Tohoku Medical Megabank Community-based Cohort Study, participants aged ≥18 years were recruited from Iwate Prefecture, with the final sample comprising 2952 subjects. Results: The FMD level was 0.5%-27.1%, with a median of 5.0% (interquartile, 4.2%-11.3%). The mean follow-up period was 5.5 ± 1.8 years (range, 0.6-6.9 years). After dividing the participants into two subgroups according to the median FMD value, a multivariate Cox regression analysis adjusting for gender, age, smoking, alcohol consumption, systolic blood pressure, low-density lipoprotein cholesterol, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, high-sensitivity cardiac troponin T and hemoglobin A1c revealed that a lower FMD value was strongly associated with incidences of total stroke (hazard ratio[HR] = 2.13, 95% confidence interval[CI] = 1.48-3.07, p < 0.001), ischemic stroke (HR = 3.33, 95%CI = 2.00-5.52, p < 0.001), nonlacunar stroke (HR = 2.77, 95%CI = 1.49-5.16, p = 0.001), and lacunar stroke (HR = 5.12, 95%CI = 1.74-16.05, p = 0.003). Conclusions: This study showed that a low FMD value might reflect vascular endothelial dysfunction and then was associated with ischemic stroke incidence in the general Japanese population, suggesting that FMD can be used as a tool to identify future stroke risk.

Impact of red blood cell distribution width-albumin ratio on prognosis of patients with CKD.

The red blood cell distribution width-albumin ratio (RAR) is a prognostic factor for adverse outcomes in various populations. However, whether RAR is associated with renal outcomes remains unclear. Therefore, we aimed to investigate the impact of RAR on the prognosis in patients with chronic kidney disease (CKD). We conducted a retrospective cohort study using 997 CKD patients who were enrolled in the Fukushima Cohort Study. Patients were categorized into tertiles (T1-3) according to the baseline RAR. The associations of RAR with end-stage kidney disease (ESKD) were assessed using Kaplan-Meier curves and multivariable cox regression analyses. Receiver operating characteristic (ROC) curves were performed to test whether significant differences were present between red cell distribution width (RDW) and RAR. The median age was 66, 57% were men, the median eGFR was 47.8 ml/min/1.73 m2, and the median value of RAR was 3.5. The higher RAR group showed an increased risk for ESKD in the Kaplan-Meier curve analysis. Compared to the lowest RAR group, higher RAR groups had a higher risk of ESKD (hazard ratio [HR] 1.37, 95% CI 0.68-2.78 and 2.92, 95% CI 1.44-5.94) for T2 and T3 groups, respectively. ROC curve analysis proved that the discriminating ability of RAR for ESKD was superior to RDW. A higher RAR value was associated with worse renal outcomes in patients with CKD. RAR could be a convenient and useful prognostic marker for renal prognosis.

The effect of lifestyle on the mortality associated with respiratory diseases in the general population.

Lifestyle factors, including smoking habit, diet, and physical activity, affect the prognosis of various diseases. We elucidated the effect of lifestyle factors and health status on deaths from respiratory diseases in the general Japanese population using data from a community health examination database. Data of the nationwide screening program of the Specific Health Check-up and Guidance System (Tokutei-Kenshin), targeting the general population in Japan, from 2008 to 2010 were analyzed. The underlying causes of death were coded according to the International Classification of Diseases (ICD)-10. The hazard ratios of the incidence of mortality associated with respiratory disease were estimated using the Cox regression model. This study included 664,926 participants aged 40-74 years, who were followed up for 7 years. There were 8051 deaths, including 1263 (15.69%) deaths from respiratory diseases. The independent risk factors of mortality associated with respiratory diseases were male sex, older age, low body mass index, no exercise habit, slow walking speed, no drinking habit, smoking history, history of cerebrovascular diseases, high hemoglobin A1c and uric acid levels, low low-density lipoprotein cholesterol level, and proteinuria. Aging and decline of physical activity are significant risk factors for mortality associated with respiratory diseases, regardless of the smoking status.

Plasma endothelin-1 may predict bevacizumab-induced proteinuria in patients with colorectal cancer.

PURPOSE: Proteinuria is one of the most common adverse events leading to the discontinuation of bevacizumab therapy. We analyzed plasma ET-1 levels as an indicator of renal endothelial dysfunction in colorectal cancer patients, to determine the utility of plasma ET-1 for identification of patients at high risk of proteinuria when treated with bevacizumab. METHODS: Patients (n = 40) were recruited from an outpatient chemotherapy center between December 2020 and January 2022. Blood samples for plasma ET-1 levels were collected before treatment with bevacizumab (baseline), and after treatment for 3 and 6 months, and plasma ET-1 was determined by ELISA. Proteinuria was evaluated based on CTCAE v5.0 using urine protein-creatinine ratio instead of 24-h urine protein. RESULTS: Plasma ET-1 levels at baseline were significantly higher in the group with grade ≥ 2 proteinuria than in the non-proteinuria group (p = 0.019). After adjusting for age, systolic and diastolic blood pressure, and hypertension following bevacizumab, plasma ET-1 levels at baseline were found to be an independent predictor of development of grade ≥ 2 proteinuria (OR = 17.8, 95% CI 1.42-223, and p = 0.026). Receiver operating characteristic curve analysis indicated an optimal cut-off value of the plasma ET-1 level of 1.19 pg/mL for predicting grade ≥ 2 proteinuria, with a sensitivity of 80.0% and specificity of 73.3%. CONCLUSION: In conclusion, higher plasma ET-1 levels before treatment might increase the risk of proteinuria in colorectal cancer patients treated with bevacizumab. This might have important implications in the early detection of the risk of proteinuria.

Association of polypharmacy with incidence of CKD: a retrospective cohort study.

BACKGROUND: Polypharmacy is common in patients with chronic kidney disease (CKD) and is associated with a decline in kidney function. However, its impact on patients without CKD has not been adequately elucidated. Therefore, we aimed to investigate the association between polypharmacy and the incidence of CKD. METHODS: We conducted retrospective cohort study using 1221 participants who were enrolled in the Fukushima Cohort Study with one or more risk factors of CKD, an estimated glomerular filtration rate (eGFR) of ≥ 60 mL/min/1.73 m2, and without proteinuria. Participants were categorized into three groups based on the number of medications: non-polypharmacy, 0-4 medications; polypharmacy, 5-9 medications; and hyper-polypharmacy, ≥ 10 medications. RESULTS: The median age was 62 years, 49% were men, the median eGFR was 75.4 ml/min/1.73 m2, and the median number of medications was 5. Polypharmacy and hyper-polypharmacy were noted in 506 (41%) and 250 (20%) participants, respectively. During follow-up, 288 participants developed CKD and 67 cardiovascular events were observed. Compared to the non-polypharmacy group, the hyper-polypharmacy group had a higher risk of CKD and cardiovascular events. The adjusted hazard ratios were 1.41 (95% CI1.01-1.99) and 2.24 (95% CI1.05-4.78) for the incidence of CKD and cardiovascular events, respectively. Sensitivity analyses yielded similar findings for the restricted cubic spline function models. CONCLUSIONS: Hyper-polypharmacy is associated with a higher risk of CKD and cardiovascular events.

Association between Plasma Xanthine Oxidoreductase Activity and the Renal Function in a General Japanese Population: The Tohoku Medical Megabank Community-Based Cohort Study.

INTRODUCTION: Xanthine oxidoreductase (XOR) has been identified as a critical source of reactive oxygen species in various pathophysiological conditions, including hypertension, endothelial dysfunction, and atherosclerosis. This study investigated the association between XOR and renal function in a general Japanese population. METHODS: The Iwate Tohoku Medical Megabank Organization pooled individual participant data from a community-based cohort study in Iwate prefecture. Chronic kidney disease (CKD) was estimated using the estimated glomerular filtration rate of cystatin C (eGFRcys). Individuals with a history of hyperuricemia or severe renal dysfunction (eGFRcys <15 mL/min/1.73 m2 or undergoing dialysis) were excluded from the study. We performed a multinominal multivariate logistic analysis adjusted for age, blood pressure, uric acid, glycated hemoglobin A1c, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol to associate XOR activity and renal function. RESULTS: The present study included 4,248 participants (male/female: 1,373/2,875, age: 62.9 ± 11.7 years). When participants were divided according to XOR quartiles, blood pressure, body mass index, uric acid, low-density lipoprotein cholesterol, and glycated hemoglobin A1c were highest in the highest XOR quartile (all p < 0.001). The XOR activity was significantly higher in the subgroup with CKD stage G3 and G4 (G1 vs. G2 vs. G3-G4: 44.8 ± 40.5 vs. 52.0 ± 42.9 vs. 54.1 ± 43.9 pmol/h/mL, p = 0.02). The higher XOR activity was significantly associated with an increase of CKD stage: the odd ratios (95% confidence intervals) per 1 pmol/h/mL increase in XOR activity with CKD stage G1 as a reference were 1.37 (1.13-1.73) in G2 and 1.51 (1.30-1.84) in G3-G4. CONCLUSION: The present study concluded that high XOR activity was associated with the severity of CKD in a general Japanese population, suggesting that upregulated XOR activity may be involved in advanced renal dysfunction.

Renal thrombotic microangiopathy and nephrotic proteinuria induced by intravitreal injection of aflibercept for diabetic macular edema.

BACKGROUND: Vascular endothelial growth factor inhibitors (VEGFIs) are used to treat malignant neoplasms and ocular diseases by inhibiting angiogenesis. Systemic use of VEGFIs has various side effects, including hypertension, proteinuria, and thrombotic microangiopathy, but adverse events due to intravitreal injection of VEGFIs have not been fully clarified. Although age-related macular degeneration was initially the most common target of intravitreal injection of VEGFIs, it has also been applied sporadically for diabetic macular edema in recent years. Proteinuria following intravitreal injection of VEGFIs would be reversible. In patients with diabetes mellitus (DM), however, it would be difficult to determine whether kidney damage arises from the clinical course of DM or from intravitreal injection of VEGFIs for diabetic macular edema. CASE PRESENTATION: A 55-year-old woman with a 20-year history of type 2 DM began intravitreal injection of VEGFI (aflibercept, 2 mg every 4 weeks) for treatment of diabetic macular edema 2 years previously. She presented with leg edema, hypertension, and nephrotic-range proteinuria 14 months after the first injection. Histological examination of renal biopsy specimens revealed diabetic nephropathy with renal thrombotic microangiopathy probably associated with intravitreal injection of VEGFI. The patient's nephrotic syndrome completely improved at 6 months after simply discontinuing aflibercept. CONCLUSIONS: This is a precious report of pathologically investigated renal thrombotic microangiopathy leading to nephrotic syndrome due to intravitreal injection of aflibercept for diabetic macular edema in a patient with type 2 DM. Renal function and proteinuria should be monitored in diabetic patients who receive intravitreal injection of a VEGFI. If kidney damage develops independent of the clinical course of DM during intravitreal injection of a VEGFI, renal biopsy should be performed and intravitreal VEGFI injection discontinued.

Association between total type I collagen N-terminal propeptide and coronary artery disease risk score in the general Japanese population.

Background: Bone metabolic dysregulation plays an important role in the pathogenesis of atherosclerosis; however, whether its markers contribute to coronary artery disease (CAD) risk in the general population remains unclear. Therefore, this study aimed to analyze the association between bone metabolic markers and CAD risk score in the general Japanese population. Methods: The Iwate Medical Megabank Organization collected individual participant data during a community-based cohort study in the Iwate prefecture (n = 5,095, age = 58.9 ± 12.4 years). Participants with osteoporosis, chronic kidney disease, malignant disease, or primary wasting disease were excluded from the study. The present study measured the levels of circulating bone metabolic markers, including total type I collagen N-terminal propeptide (TP1NP), bone-type alkaline phosphatase, cross-linked N-telopeptide of type 1 collagen (NTX), and intact parathyroid hormone. CAD risk and atherosclerosis were evaluated using the Suita score and brachial-ankle pulse wave velocity (baPWV) measurement, respectively. Results: Among the bone metabolic markers, TP1NP was strongly associated with a high Suita score (≥56 points) (OR = 0.77, 95% CI = 0.69-0.82, P < 0.001). When participants were divided into quartiles of TP1NP levels, the subgroup with the lowest TP1NP level was associated with a high Suita score (≥56 points) and high baPWV (>1,400 cm/s). Conclusions: This study demonstrated that TP1NP levels decreased in participants with high Suita scores and high baPWV, suggesting that TP1NP downregulation may indicate future CAD risk and atherosclerosis progression in the general Japanese population.

Healthy Lifestyle and Incident Hypertension and Diabetes in Participants with and without Chronic Kidney Disease: The Japan Specific Health Checkups (J-SHC) Study.

Objective Whether or not combined lifestyle factors are associated with similar decreases in risks of incident hypertension and diabetes among individuals with and without chronic kidney disease (CKD) remains unclear. Methods This population-based prospective cohort study included participants 40-74 years old who were free from heart disease, stroke, renal failure, hypertension, diabetes, and hypercholesterolemia at baseline (n =60,234). Healthy lifestyle scores (HLSs) were calculated by adding the total number of 5 healthy lifestyle factors (non-smoking, body mass index <25 kg/m2, regular exercise, healthy eating habits, and moderate or less alcohol consumption). Cox proportional hazards models were used to examine associations between the HLS and incident hypertension or type 2 diabetes and whether or not CKD modified these associations. Results During a median of 4 years, there were 2,773 incident hypertension cases (30.1 cases per 1,000 person-years) and 263 incident diabetes cases (2.4 cases per 1,000 person-years). The risk of developing hypertension and diabetes decreased linearly as participants adhered to more HLS components. Compared with adhering to 0, 1, or 2 components, adherence to all 5 HLS components was associated with a nearly one-half reduction in the risk of hypertension [hazard ratio (HR) =0.52; 95% confidence interval (CI), 0.45-0.60] and diabetes (HR=0.51; 95% CI, 0.32-0.81) in fully adjusted models. CKD did not have a modifying effect on associations between the HLS and incident hypertension (Pinteraction=0.6) or diabetes (Pinteraction=0.3). Conclusion Adherence to HLS components was associated with reduced risks of incident hypertension and diabetes, regardless of CKD status.

Cost-effectiveness of mass screening for dipstick hematuria in Japan.

BACKGROUND: Dipstick urine tests are a simple and inexpensive method for detecting kidney and urological diseases, such as IgA nephropathy and bladder cancer. The nationwide mass screening program, Specific Health Checkup (SHC), started in Japan in 2008 and targeted all adults between 40 and 74 years of age. Dipstick urine tests for proteinuria and glucosuria are mandatory as part of the SHC, but dipstick urine tests for hematuria are not. However, the dipstick hematuria test is often administered simultaneously with these mandatory tests by some health insurers. Hematuria is common in Japanese general screening participants, particularly elderly women, and the necessity of mass screening using the dipstick hematuria test has been discussed. This study aimed to evaluate the cost-effectiveness of mass screening for dipstick hematuria tests in addition to the SHC. METHODS: Using a decision tree and Markov modeling, we conducted a cost-effectiveness analysis from a Japanese societal perspective. RESULTS: Compared with the current SHC, mass screening for dipstick hematuria tests, in addition to the SHC, costs less and gains more, which means cost-saving. Similar findings were observed in the sex-specific analysis. CONCLUSION: Our results suggest that mandating the dipstick hematuria test could be justifiable as an efficient use of finite healthcare resources. The results have implications for mass screening programs not only in Japan but worldwide.

Association between high-sensitivity cardiac troponin T levels and incident stroke in the elderly Japanese population: Results from the Tohoku Medical Megabank Community-based Cohort Study.

Elevated levels of circulating high-sensitivity cardiac troponin T (hs-cTnT) are associated with cardiovascular disease. This study aimed to examine whether hs-cTnT levels are associated with incident stroke in the elderly population. The Iwate Tohoku Medical Megabank Organization pooled participant data for a community-based cohort study (n = 15,063, 69.6 ± 3.4 years), with a mean follow-up period of 5.23 years for all-cause death and incident stroke. The follow-up revealed 316 incident strokes, including atherothrombotic (n = 98), cardioembolic (n = 54), lacunar (n = 63), hemorrhagic (n = 101), and 178 all-cause deaths. Participants were classified into quartiles according to hs-cTnT levels (Q1 ≦ 4 ng/L, Q2: 5-6 ng/L, Q3: 7-9 ng/L, and Q4 > 9 ng/L). After adjusting for sex, age, smoking, drinking, systolic blood pressure, estimated glomerular filtration rate, N-terminal pro-brain natriuretic peptide, hemoglobin A1c, and lipid profile, a Cox proportional hazard model showed that higher hs-cTnT levels were associated with ischemic stroke (Q1 vs. Q4, hazard ratio [HR] = 2.24, 95 % confidence interval [CI] = 1.12-4.51, p = 0.023). The incident of total stroke was not associated with hs-cTnT levels (Q1 vs. Q4, HR 1.39, 95 % CI = 0.89-1.74, p = 0.145). Numerical differences were highest regarding incident lacunar stroke subtypes; however, this association was not statistically significant. Higher hs-cTnT concentrations were associated with ischemic stroke in the elderly Japanese population.

Association of Polypharmacy with Kidney Disease Progression in Adults with CKD.

BACKGROUND AND OBJECTIVE: Polypharmacy is common in patients with CKD and reportedly associated with adverse outcomes. However, its effect on kidney outcomes among patients with CKD has not been adequately elucidated. Hence, this investigation was aimed at exploring the association between polypharmacy and kidney failure requiring KRT. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: We retrospectively examined 1117 participants (median age, 66 years; 56% male; median eGFR, 48 ml/min per 1.73 m2) enrolled in the Fukushima CKD Cohort Study to investigate the association between the number of prescribed medications and adverse outcomes such as kidney failure, all-cause mortality, and cardiovascular events in Japanese patients with nondialysis-dependent CKD. Polypharmacy and hyperpolypharmacy were defined as the regular use of 5-9 and ≥10 medications per day, respectively. RESULTS: The median number of medications was eight; the prevalence of polypharmacy and hyperpolypharmacy was each 38%. During the observation period (median, 4.8 years), 120 developed kidney failure, 153 developed cardiovascular events, and 109 died. Compared with the use of fewer than five medications, adjusted hazard ratios (95% confidence intervals) associated with polypharmacy and hyperpolypharmacy were 2.28 (1.00 to 5.21) and 2.83 (1.21 to 6.66) for kidney failure, 1.60 (0.85 to 3.04) and 3.02 (1.59 to 5.74) for cardiovascular events, and 1.25 (0.62 to 2.53) and 2.80 (1.41 to 5.54) for all-cause mortality. CONCLUSIONS: The use of a high number of medications was associated with a high risk of kidney failure, cardiovascular events, and all-cause mortality in Japanese patients with nondialysis-dependent CKD under nephrology care.

Trace proteinuria as a risk factor for cancer death in a general population.

Growing evidence has demonstrated an association between nondialysis chronic kidney disease and cancer incidence, although the association between trace proteinuria and cancer death remains unclear. The aim of this study was to investigate the association between trace proteinuria and cancer death in a community-based population in Japan. This was a prospective cohort study of 377,202 adults who participated in the Japanese Specific Health Check and Guidance System from 2008 to 2011. Exposure was dipstick proteinuria categorized as - (negative), ± (trace), 1 + (mild), or ≥ 2 + (moderate to heavy). Outcome was cancer death based on information from the national database of death certificates. Adjusted Cox hazard regression model was used to evaluate the associations between trace proteinuria and cancer death. During median follow-up of 3.7 years, 3056 cancer deaths occurred, corresponding to overall cancer death rate of 21.7/10,000 person-years. In the fully adjusted model, risk of cancer death increased significantly in each successive category of proteinuria: hazard ratio (HR) (95% confidence interval [95% CI]) for risk of cancer death was 1.16 (1.03-1.31), 1.47 (1.27-1.70), and 1.61 (1.33-1.96) for trace, mild, and moderate to heavy proteinuria, respectively. Sensitivity analyses revealed a similar association between trace proteinuria and cancer death, and participants with trace proteinuria had greater risk of mortality from hematological cancers (HR: 1.59 [95% CI: 1.09-2.31]). Both mild to heavy and trace proteinuria were significantly associated with risk of mortality from cancer in a general population.

The distribution of eGFR by age in a community-based healthy population: the Japan specific health checkups study (J-SHC study).

BACKGROUND: Renal function gradually declines with age. However, the association between changes in renal function and healthy aging has not been determined. This study examined the distribution of estimated glomerular filtration rate (eGFR) values in healthy subjects by age using large-scale cross-sectional data of health check-up participants in Japan. METHODS: Among the 394,180 health check-up participants, 75,217 (19.1%) subjects without hypertension, diabetes, hyperlipidemia, obesity, proteinuria, smoking, past history of cardiovascular diseases, and renal failure/not undergoing dialysis were included in the healthy group. The distribution of eGFR values was determined at each age between 39 and 74 years. RESULTS: in healthy subjects, the mean (± 2 SD range) values of eGFR (mL/min/1.73 m2) at ages 40, 50, 60, and 70 were 88.0 (55.4-121.7), 82.3 (51.2-113.3), 77.8 (48.1-107.6), and 72.9 (44.7-101.1), respectively. The difference in the mean eGFR by age was almost constant across all ages. In the linear regression analysis adjusted for sex, the regression coefficient of mean eGFR for a one-year increase in age was -0.46 mL/min/1.73 m2 in healthy subjects (P < 0.001). By sex, the distribution of eGFR and the 1-year change in eGFR showed similar results in both men and women. CONCLUSIONS: Renal function slowly declined with age in a healthy population; however, it was relatively preserved until the mid 70 s. This result suggests that a decline in renal function often observed in the elderly does not attribute to aging alone, and further examination might be required to clarify the cause of renal impairment.

One-year change in plasma volume and mortality in the Japanese general population: An observational cohort study.

BACKGROUND: Changes in plasma volume, a marker of plasma volume expansion and contraction, are gaining attention in the field of cardiovascular disease because of its role in the prevention and management of heart failure. However, it remains unknown whether a 1-year change in plasma volume is a risk factor for all-cause, cardiovascular, and non-cardiovascular mortality in the general population. METHODS AND RESULTS: We used a nationwide database of 134,291 subjects (age 40-75 years) who participated in the annual "Specific Health Check and Guidance in Japan" check-up for 2 consecutive years between 2008 and 2011. A 1-year change in plasm volume was calculated using the Strauss-Davis-Rosenbaum formula. There were 220 cardiovascular deaths, 1,001 non-cardiovascular deaths including 718 cancer deaths, and 1,221 all-cause deaths during the follow-up period of 3.9 years. All subjects were divided into quintiles based on the 1-year change in plasma volume. Kaplan-Meier analysis demonstrated that the highest 5th quintile had the greatest risk among the five groups. Multivariate Cox proportional hazard regression analysis demonstrated that a 1-year change in plasma volume was an independent risk factor for all-cause, cardiovascular, non-cardiovascular, and cancer deaths. The addition of a 1-year change in plasma volume to cardiovascular risk factors significantly improved the C-statistic, net reclassification, and integrated discrimination indexes. CONCLUSIONS: Here, we have demonstrated for the first time that a 1-year change in plasma volume could be an additional risk factor for all-cause, cardiovascular, and non-cardiovascular (mainly cancer) mortality in the general population.

High FIB4 index is an independent risk factor of diabetic kidney disease in type 2 diabetes.

Nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH) may be linked to development of chronic kidney diseases (CKD). The FIB4 index, a noninvasive liver fibrosis score, has been reported to predict CKD in non-diabetic patients, but there are no reports yet in diabetic cases. Therefore, we evaluated the prognostic impact of FIB4 index on the risk of developing diabetic kidney disease (DKD) in Japanese patients with type 2 diabetes in a retrospective cohort study. We assessed patients with type 2 diabetes with an eGFR ≥ 60 mL/min/1.73 m2 and without dipstick positive proteinuria (≥ 1 +) at their first visit to our department. Participants were divided into two groups based on the FIB4 index at their first visit: FIB4 index > 1.3 and FIB4 index ≤ 1.3. The primary endpoint was defined as a decrease in eGFR < 60 mL/min/1.73 m2 or the onset of proteinuria during the course of treatment. The average age of all 584 type 2 diabetic participants (360 [61.6%] men) was 55 ± 11 years. There were 187 patients in the FIB4 index group > 1.3 (32.0%) and the median observation period was 6.0 (3.8-11.0) years. Kaplan-Meier survival analysis indicated that the risks of developing DKD, eGFR < 60 and proteinuria were all higher in FIB4 index > 1.3 patients than in FIB4 ≤ 1.3 patients. In the Cox regression analysis, an FIB4 index > 1.3 was a significant predictor for onset of DKD (HR 1.54, 95% CI 1.15-2.08) and proteinuria (HR 1.55, 95% CI 1.08-2.23), but not for an eGFR < 60 (HR 1.14, 95% CI 0.79-1.99). To the best of our knowledge, this is the first study to demonstrate that an FIB4 index > 1.3 has a prognostic impact on the development of CKD and proteinuria in type 2 diabetic patients. This warrants further investigation of the prognostic impact of the development of DKD or proteinuria.

Estimating the prevalence of definitive chronic kidney disease in the Japanese general population.

BACKGROUND: Most data on chronic kidney disease (CKD) prevalence has been based on single measurements of renal function and proteinuria. The aim was to determine the prevalence of CKD diagnosed by chronic proteinuria and/or reduced eGFR in a recent year in Japan. METHODS: In the main study, using a population-based cohort in Japan, the overall prevalence of CKD, defined as persistent positive proteinuria and/or eGFR < 60 ml/min/1.73 m2, was determined. Of 2,849,557 persons, 763,104 had data for eGFR and proteinuria in both 2014 and 2015. For estimating number of CKD cases in Japanese adults, a regional cohort data with age ranging 22-87 years (N = 22,037) was further applied to the analysis. RESULTS: Definitive CKD was present in 2.3-23.0% of men and 1.7-17.1% of women age from 40 to 74 years in the main cohort. The estimated prevalence of reduced eGFR and/or proteinuria in the baseline year alone was 15.7% in men and 13.6% in women; the prevalence of definitive CKD was 10.9% in men and 9.2% in women. The number of CKD cases based on a single-year test in Japanese adults over 20 years of age increased from 13.3 million to 14.8 million between 2005 and 2015. CONCLUSIONS: Recent changes in prevalence of CKD seem to be mainly caused by an increase in Japan's elderly population. Although past reports may lead to overdiagnosis of CKD by a single-year test, the estimated number of definitive CKD was 10.2 million in 2015.

The Effect of CKD on Associations between Lifestyle Factors and All-cause, Cancer, and Cardiovascular Mortality: A Population-based Cohort Study.

Objective Results from previous studies on the dose-dependent effect of adhering to multiple lifestyle factors on all-cause mortality in patients with chronic kidney disease (CKD) are inconsistent, despite the reported dose-dependent effect in the general population. This study aimed to examine whether CKD modifies the dose-dependent effect of adhering to multiple lifestyle factors on mortality. Methods This population-based prospective cohort study targeted 262,011 men and women aged 40-74 years at baseline. Of these, 18.5% had CKD, which was defined as GFR <60 mL/min/1.73 m2, ≥1+ proteinuria on urinalysis, or both. The following lifestyle behaviors were considered healthy: no smoking, body mass index <25 kg/m2, moderate or lower alcohol consumption, regular exercise, and healthy eating habits. Healthy lifestyle scores were calculated by adding the total number of lifestyle factors for which each participant was at low risk. Cox proportional hazards models were used to examine associations between healthy lifestyle scores and all-cause, cancer, and cardiovascular mortality, and whether CKD modified these associations. Results During a median follow-up of 4.7 years, 3,471 participants died. The risks of all-cause and cancer mortality decreased as the number of five healthy lifestyle factors that were adhered to increased, irrespective of the CKD status. The risk of cardiovascular mortality, however, was modified by CKD (interaction p=0.07), and an unhealthy lifestyle and CKD synergistically increased cardiovascular mortality. Conclusion A healthy lifestyle can reduce the risk of all-cause and cancer death in patients with or without CKD, while the prevention of CKD is essential for reducing the risk of cardiovascular death.