Pulse pressure modifies the association between diastolic blood pressure and decrease in kidney function: the Japan Specific Health Checkups Study.

Background: Unlike systolic blood pressure (SBP), the prognostic value of diastolic blood pressure (DBP) in kidney function has not been established. We hypothesized that pulse pressure (PP), which is associated with arteriosclerosis, would affect the prognostic value of DBP. Methods: This longitudinal study used data from the Japan Specific Health Checkups Study was conducted between 2008 and 2014. The participants were stratified into three PP subgroups (low PP ≤39, normal PP 40-59 and high PP ≥60 mmHg). The exposures of interest were SBP and DBP, and the association between SBP/DBP and kidney outcomes (30% decline in the estimated glomerular filtration rate from baseline) was examined in each PP subgroup using a Cox proportional hazards model. Results: Among 725 022 participants, 20 414 (2.8%) developed kidney outcomes during a median follow-up period of 34.6 months. Higher SBP was consistently associated with a higher incidence of kidney outcome in all PP subgroups. Although DBP had a positive linear association with the incidence of kidney outcome in low- and normal-PP subgroups, both lower (≤60 mmHg) and higher (≥101 mmHg) DBP were associated with a higher incidence of kidney outcome in the high-PP subgroup, with a U-shaped curve. Hazard ratios (95% confidence intervals) of ≤60 mmHg (reference: 61-80 mmHg in normal-PP subgroup) and ≥101 mmHg were 1.26 (1.15-1.38) and 1.86 (1.62-2.14), respectively. Conclusions: In this large population-based cohort, DBP was differently associated with kidney outcome by PP level; lower DBP was significantly associated with a higher incidence of kidney outcome in the high-PP subgroup but not in the low- and normal-PP subgroups.

Systemic Capillary Responses to Acute Exercise in Hypertensive Seniors: Insights from a Single-Center Pilot Study.

Objective: The aim of this study was to investigate nailfold capillary parameters in community-dwelling individuals aged over 60 years who have hypertension and do not exercise regularly. Furthermore, the study examined the correlations between capillary function and other health-related indicators. DESIGN: This study was a single- center pilot trial. SETTING: The study took place in the Faculty of Health, Tsukuba University of Technology, Japan. PARTICIPANTS: Hypertensive community-dwelling elderly people took part in the study. INTERVENTION: Microcirculation was observed before and 1 min after an arm-curl exercise by means of capillary microscopy of the non-exercised limb. Additionally, we examined other health-related indicators. Methods: We measured the acute effects of reperfusion on nailfold density, flow, and diameters. Secondary outcomes included the correlations between microvascular parameters and other health-related indicators. We hypothesized that brief exercise could enhance microcirculation reperfusion and correlate with other health-related parameters. Results: There were 20 participants with a mean (SD) age of 67.1 (5.8) years. The capillary flow rate changed from 2.3 ± 6.7 to 2.7 ± 0.2 log µm/s (p < 0.01), and the capillary density changed from 0.8 ± 0.2 to 0.9 ± 0.1 log/mm (p < 0.01), which included a significant increase in the non-exercising limb. Significant correlations were observed between the nailfold capillary diameter and body fat mass, the capillary diameter and physical activity, and the capillary density and bone mineral density. Conclusions: The acute effects of exercise on high-risk elderly individuals can be safe, and even 1 of min exercise can potentially improve their nailfold capillary function, despite the brief time, compared to no exercise. The results indicate that capillaries have an impact on the function of the whole body. Thus, they may be a useful diagnostic tool for assessing nailfold capillaries.

Factors affecting the sodium-glucose cotransporter 2 inhibitors-related initial decline in glomerular filtration rate and its possible effect on kidney outcome in chronic kidney disease with type 2 diabetes: The Japan Chronic Kidney Disease Database.

AIM: Sodium-glucose cotransporter 2 (SGLT2) inhibitors often cause a transient decrease in glomerular filtration rate (GFR) shortly after the initiation, referred to as the 'initial drop'. However, the clinical significance of this initial drop in real-world practice remains unclear. MATERIALS AND METHODS: Using the nationwide Japan Chronic Kidney Disease Database, we examined factors that affected the initial drop, in patients with chronic kidney disease (CKD) and type 2 diabetes mellitus (T2DM). We also evaluated the effects of the initial drop on a composite kidney outcome (a decline in GFR of ≥50% or progression to end-stage kidney disease). RESULTS: Data from 2053 patients with CKD and T2DM newly prescribed an SGLT2 inhibitor were analysed. The follow-up period after SGLT2 inhibitor administration was 1015 days (interquartile range: 532, 1678). Multivariate linear regression models revealed that the concomitant use of the renin-angiotensin system inhibitors and diuretics, urinary protein levels ≥2+, and changes in GFR before the initiation of the SGLT2 inhibitor were associated with a larger initial GFR decline (ß = -0.609, p = .039; ß = -2.298, p < .001; ß = -0.936, p = .048; ß = -0.079, p < .001, respectively). Patients in the quartile with the largest initial GFR decline experienced a higher incidence of the subsequent composite kidney outcome than those in the other quartiles (p < .001). CONCLUSIONS: The concomitant use of renin-angiotensin system inhibitors and diuretics, higher urine protein levels and pre-treatment GFR changes were associated with a larger initial GFR decline. Of these factors, the use of a diuretic had the largest effect. Furthermore, patients with CKD and T2DM experiencing an excessive initial GFR drop might be at a higher risk of adverse kidney outcomes.

Evaluating the associations between compliance with CKD guideline component metrics and renal outcomes.

Understanding the association between compliance to the Chronic Kidney Disease (CKD) guidelines in real-world clinical settings and renal outcomes remains a critical gap in knowledge. A comprehensive analysis was conducted using data from a national, multicenter CKD registry. This study included 4,455 patients with an estimated glomerular filtration rate (eGFR) measurement on the index date and eight additional metrics recorded within six months. These metrics comprised serum electrolyte levels, low-density lipoprotein cholesterol, hemoglobin, and the use of renin-angiotensin system inhibitors. The primary outcome was a composite of renal events, defined by a decline in eGFR to < 15 mL/min/1.73 m2 or a reduction of ≥ 30% in eGFR, confirmed by follow-up tests. Over a median follow-up of 513 days, 838 renal events were observed. High serum potassium levels (> 5.4 mmol/L) were associated with increased event rates compared to lower levels. Similarly, low serum sodium-chloride levels (< 33) correlated with higher event rates. Usage of renin-angiotensin system inhibitors, low serum calcium (< 8.4 mg/dL), and high uric acid levels (> 7.0 mg/dL) were also linked to increased events. Conversely, higher hemoglobin levels (≥ 13 g/dL) were associated with lower event rates. Compliance to guidelines, categorized into quartiles based on the number of met metrics, revealed a significantly reduced risk of events in the highest compliance group (meeting 8 metrics) compared to the lowest (0-5 metrics). Compliance to CKD guidelines in clinical practice is significantly associated with improved renal outcomes, emphasizing the need for guideline-concordant care in the management of CKD.

Exercise instruction during haemodialysis treatment after changes to the insurance regime: a nationwide questionnaire survey in Japan.

In April 2022, an additional medical fee for exercise instruction during haemodialysis treatment was approved for insurance claims in Japan. We conducted a questionnaire survey to investigate the current situation regarding exercise therapy during haemodialysis treatment after this change. Questionnaires were mailed to 4257 haemodialysis facilities, almost all the haemodialysis facilities in Japan, on January 31, 2023. In total, 1657 facilities responded, of which 550 (33%) provided exercise instruction during haemodialysis treatment, and 65% of these claimed the new fee. Of the 550 facilities that had claimed the fee at the time of survey, 245 (55%) started exercise instruction in April 2022 or later. Exercise instruction focused on resistance training (81%) and aerobic exercise (62%) for 20-30 min (66%) three times a week (80%). The instructors included physicians in 45% of facilities, nurses in 74%, and physical therapists in 36%. Efficacy was evaluated in 76% of the facilities providing instruction, mainly by assessing change in muscle strength (49%). Overall, 39% of facilities had experienced some adverse events, but none were life-threatening. In conclusion, after the change in the insurance regime, exercise instruction during haemodialysis treatment has become more popular, and more patients on haemodialysis are undergoing exercise therapy.

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.

NT-pro BNP level at dialysis initiation is a useful biomarker for predicting hospitalization for ischemic heart disease.

BACKGROUND: Patients with end-stage kidney disease (ESKD) are at high risk of cardiovascular disease including stroke, heart failure, and ischemic heart disease (IHD). To prevent the occurrence and progression of CVD, a reliable prognostic cardiac biomarker is essential. We investigated the prognostic value of NT-proBNP for each incident type of CVD. METHODS: Male patients from the Ibaraki Dialysis Initiation Cohort (iDIC) study with preserved serum samples from dialysis initiation day (n = 212) were analyzed. Patients were classified into four groups according to quartiles of baseline NT-pro BNP levels. The relationship between NT-proBNP levels at the initiation of dialysis and the subsequent incidence of hospitalization events due to IHD, heart failure, and stroke was analyzed. RESULTS: The incidence rate for hospitalization due to IHD was significantly higher in the highest NT-proBNP category (Log rank p = 0.008); those of stroke and heart failure showed no significant differences among quartiles. Cox proportional hazards regression analysis revealed that serum NT-proBNT was the only prognostic factor for hospitalization for IHD after adjustment by major known IHD risk factors. (HR, 1.008; 95% confidence interval, 1.002-1.014; p = 0.01) The ROC curve analysis for the incidence of hospitalization due to IHD showed that NT-proBNP had an area under the curve (AUC) of 0.759 (95% CI 0.622-0.897; p = 0.004) at a cut-off value of 956.6 pg/mL. CONCLUSION: NT-proBNP measurement at the initiation of dialysis therapy is useful to predict later hospitalization for IHD. TRIAL REGISTRATION: UMIN000010806.

Health-related Quality of Life in 10 years Long-term Survivors of Chronic Kidney Disease: A From-J Study.

OBJECTIVE: The Chronic Kidney Disease (CKD) practice facilitation program in the Frontier of Renal Outcome Modifications in Japan study reduced cardiovascular disease (CVD) events in patients with CKD. 10-year long-term survivors with CKD lived with serious complications, including end-stage kidney disease and CVD. This study aimed to measure health-related quality of life in 10-year long-term CKD survivors and examine the predictors and determinants of clinical indices for measured quality of life (QOL) scores. METHODS: The EQ-5D-5L, a generic preference-based instrument, was administered to 1,473 CKD survivors enrolled in the Frontier of Renal Outcome Modifications in JapanFrontier of Renal Outcome Modifications in JapanFrontier of Renal Outcome Modifications in Japan study. The 10th-year data collection was performed by either primary care physicians or participants who filled out questionnaires from October 2018 to March 31, 2019. RESULTS: The response rate was 38.2% (423/1,473). The mean QOL score was 0.893 (95% confidence interval (CI), 0.880-0.906), and the median QOL score was 1.000 (interquartile range (IQR), 0.826-1.000). The mean QOL score in participants with renal replacement therapy was 0.824 (95% CI, 0.767-0.881), and the median was 0.828 (IQR, 0.755-1.000). The mean QOL score in participants with CVD was 0.877 (95% CI, 0.811-0.943), and the median was 1.000 (IQR, 0.723-1.000). The mean QOL score in participants with 50% decline in estimated glomerular filtration was 0.893 (95% CI, 0.860-0.926), and the median was 0.889 (IQR, 0.825-1.000). The decrease in QOL scores with baseline CKD stages was significant according to the Jonckheere-Terpstra test for trend (P = .002). Baseline age, systolic blood pressure, and history of hyperuricemia were significant predictors of 10th-year QOL scores. CONCLUSION: We suggest that CKD complications negatively affect the QOL scores in 10-year long-term survivors with CKD. CKD guideline-based practices, prevention of end-stage kidney disease/CVD and management of hypertension, diabetes and hyperuricemia, might contribute to future health-related quality of life in patients with CKD.

Predictors of damage accrual in patients with antineutrophil cytoplasmic antibody-associated vasculitis: A nationwide prospective study.

OBJECTIVES: This study elucidated the prognosis and risk factors associated with damage accrual during long-term remission maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: We obtained data from 120 patients registered in a nationwide prospective cohort study on remission induction therapy in Japanese patients with AAV and rapidly progressive glomerulonephritis (RemIT-JAV-RPGN), who achieved remission at 24 months after treatment initiation and were followed up for additional 24 months. The primary outcome was the vasculitis damage index (VDI) score at Month 48, and the secondary outcome included risk factors associated with increased total VDI at Month 48. RESULTS: The understudied patients comprised 52 men and 68 women aged 68 ± 13 years. Between Months 25 and 48, the patients' survival rate was 95% (114/120). End-stage renal disease developed in seven patients by Month 48, and 64 cases had increased VDI. The multivariable analysis results revealed that oral prednisolone (PSL) doses at Month 24 were associated with damage accrual between Months 24 and 48. CONCLUSIONS: VDI accrual was observed in more than half of patients with AAV during maintenance therapy, and increased VDI scores were associated with oral PSL doses 24 months after initiating remission induction therapy in Japan.

Cardiorenal damages in mice at early phase after intervention induced by angiotensin II, nephrectomy, and salt intake.

The interconnection of heart performance and kidney function plays an important role for maintaining homeostasis through a variety of physiological crosstalk between these organs. It has been suggested that acute or chronic dysfunction in one organ causes dysregulation in another one, like patients with cardiorenal syndrome. Despite its growing recognition as global health issues, still little is known on pathophysiological evaluation between the two organs. Previously, we established a preclinical murine model with cardiac hypertrophy and fibrosis, and impaired kidney function with renal enlargement and increased urinary albumin levels induced by co-treatment with vasopressor angiotensin II (A), unilateral nephrectomy (N), and salt loading (S) (defined as ANS treatment) for 4 weeks. However, how both tissues, heart and kidney, are initially affected by ANS treatment during the progression of tissue damages remains to be determined. Here, at one week after ANS treatment, we found that cardiac function in ANS-treated mice (ANS mice) are sustained despite hypertrophy. On the other hand, kidney dysfunction is evident in ANS mice, associated with high blood pressure, enlarged glomeruli, increased levels of urinary albumin and urinary neutrophil gelatinase-associated lipocalin, and reduced creatinine clearance. Our results suggest that cardiorenal tissues become damaged at one week after ANS treatment and that ANS mice are useful as a model causing transition from early to late-stage damages of cardiorenal tissues.

Association of Lower Extremity Muscle Strength and Function with Renal Resistive Index in Individuals with and without Chronic Kidney Disease.

Age-related loss of lower extremity muscle strength is pronounced in individuals with chronic kidney disease (CKD). In contrast, an increase in intrarenal flow pulsatility results in initial age-related changes in renal hemodynamics, leading to the development of CKD. To date, it remains unclear whether lower extremity muscle strength determines elevated renal flow pulsatility. This study aimed to determine the association of lower extremity muscle strength and function with intrarenal hemodynamics in individuals with and without CKD. One hundred seventy-six individuals without CKD (aged 63 ± 9 years) and 101 individuals with CKD (aged 66 ± 8 years) were included in this study. Using Doppler ultrasound, the renal resistive index (RI) was measured as a parameter of renal hemodynamics. Knee extensor muscle strength (KES), gait speed (GS), and the 30 s chair stand test (30s-CST) were used to measure lower extremity muscle strength and function. Multivariate analyses showed that GS and 30s-CST scores were independent determinants of renal RI, whereas the KES score was not associated with renal RI in individuals with and without CKD. In the two-way analysis of covariance, renal RI was the highest in individuals with CKD who had lower KES, GS, and 30s-CST scores. Reduced lower extremity muscle strength and function are independent determinants of elevated renal flow pulsatility in individuals with and without CKD.

Predictors of Hyporesponsiveness to Erythropoiesis-Stimulating Agents in Patients with Non-Dialysis-Dependent Chronic Kidney Disease (RADIANCE-CKD Study).

INTRODUCTION: Hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) has been associated with increased mortality and cardiovascular events in patients with chronic kidney disease. We hypothesized that the prediction of ESA resistance during ESA administration would be very useful in deciding on a treatment plan. METHODS: Patients enrolled in a randomized controlled trial to evaluate renal prognosis in anemic patients with non-dialysis-dependent chronic kidney disease with hyporesponsiveness to ESA were included; the patients had different target hemoglobin levels. A landmark analysis was performed at 3 months into the study. To construct a predictive model for the severe ESA hypo-responder group, in which there was no increase in hemoglobin even with active treatment, background factors and serum test items that affect anemia at study entry were included in a logistic regression model, the area under the curve (AUC) and 95% confidence intervals (CI) were estimated, and sensitivity and specificity were calculated. This study was a post hoc sub-analysis of a randomized controlled trial. RESULTS: The AUC for the 19 existing risk factors as predictors was 0.783 (95% CI: 0.711-0.855). Among the 19 risk factors, the combination of six factors (hemoglobin level, systolic blood pressure, weight, gender, smoking status, and hypertensive retinopathy) with the largest χ2 statistics were selected by multiple logistics regression. The AUC for these 6 predictors was 0.716 (95% CI: 0.634-0.799). To the six existing risk factors, five serum test items that affect anemia (vitamin B12, vitamin B6, folic acid, parathyroid hormone, and 25-hydroxyvitamin D) were added, for a total of 11 risk factors, with a similar AUC of 0.736 (95% CI: 0.655-0.817), sufficient to predict ESA resistance. CONCLUSIONS: Our results suggest that existing risk factors and serum test items can be used to predict ESA resistance in patients with non-dialysis-dependent chronic kidney disease on ESA.

Synergistic effect of proteinuria on dipstick hematuria-related decline in kidney function: The Japan Specific Health Checkups (J-SHC) Study.

BACKGROUND: The effect of isolated hematuria without proteinuria on kidney function decline, and the modification by the severity of proteinuria in general population are not fully elucidated. METHODS: Participants were included in the Japan Specific Health Checkups Study between 2008 and 2014. The exposure of interest was the frequency of dipstick hematuria during the observation. In each proteinuria frequency category (non-, occasional, persistent), hematuria-related decline in the eGFR rate was examined by analysis of covariance (ANCOVA). eGFR decline trajectories were also assessed using mixed-effects models. RESULTS: Among the 552,951 participants, 146,753 (26.5%) had hematuria, and 56,021 (10.1%) and 8,061 (1.5%) had occasional and persistent proteinuria, respectively. During the median follow-up of 3.0 years, annual change in eGFR decline in participants with hematuria was significantly faster than in those without hematuria (mean [95% confidence interval]: - 0.95 [- 0.98 to - 0.92] vs - 0.86 [- 0.87 to - 0.84] mL/min/1.73 m2/year; P < 0.001). In ANCOVA, the hematuria-related annual eGFR decline rate increased as proteinuria frequency categories increased (differences in annual eGFR decline rate between participants with and without hematuria: 0.08 [0.06 to 0.09] in participants with non-proteinuria category, 0.17 [0.15 to 0.18] in occasional proteinuria category, and 0.68 [0.65 to 0.71] mL/min/1.73 m2/year in persistent proteinuria category; P for interaction < 0.001). Similar results were obtained by the linear mixed-effect model. CONCLUSIONS: Proteinuria has a synergistic effect on dipstick hematuria-related decline in kidney function. Among the general population without proteinuria throughout the observational period, the "isolated hematuria"-related eGFR decline was statistically significant but the difference was small.

Weight Loss Improves Liver Dysfunction and Dipstick Proteinuria in Obesity: The Japan Specific Health Checkups Study.

Introduction: Obesity and inappropriate lifestyle is the major risk factors for liver dysfunction and proteinuria. Nevertheless, previous studies have not described the differential impacts of body weight changes and lifestyle modification on already developed liver dysfunction and proteinuria. Methods: The original cohort was 933,490 individuals from the Japanese general population. In this investigation, we included 36,256 obese individuals with elevated levels of aspartate aminotransferase and/or alanine aminotransferase (≥31 IU/L) or positive proteinuria (+/- or more) in both the first and second years. Outcomes were the first normalization of these data defined as improvement in liver dysfunction and proteinuria. Times to outcomes were assessed using the Cox proportional hazards modeling for -1 kg/m2/year change in body mass index (BMI) changes in exercise and alcohol intake. Results: The multivariable-adjusted hazard ratio (HR) for incident improvement in liver dysfunction with BMI change -1.0 kg/m2/year was 1.07 (95% confidence interval [CI] 1.05-1.09) in obesity and that with improved proteinuria was 1.04 (95%CI 1.02-1.07). Compared to subjects without exercise habits, subjects who gained exercise habits exhibited a higher rate of improvement in liver dysfunction (HR 1.08; 95%CI 1.01-1.15) but not in proteinuria (HR 0.98; 95%CI 0.88-1.08). Compared to subjects with continuous alcohol intake habits, subjects who quit alcohol intake also showed a higher rate of improvement in liver dysfunction (HR 1.20; 95%CI 1.09-1.32). Conclusions: This study suggested that weight loss greater than 1 kg/m2/year improves liver dysfunction and dipstick proteinuria in obesity. Particularly, liver dysfunction can be remedied by acquiring an exercise habit and quitting alcohol intake.

Trace proteinuria detected via dipstick test is associated with kidney function decline and new-onset overt proteinuria: the Japan Specific Health Checkups (J-SHC) Study.

BACKGROUND: Microalbuminuria is associated with mortality, cardiovascular disease, and end-stage kidney disease. The association between trace proteinuria (detected via dipstick test) and kidney outcomes is unclear. METHODS: This nationwide longitudinal study used data from the Japan Specific Health Checkups Study conducted during 2008-2014. The frequency of trace proteinuria (detected via dipstick test) during first two visits was used as an exposure variable (TrUP 0/2, no trace proteinuria; TrUP 1/2, detected once; TrUP 2/2, detected twice), and kidney outcomes were evaluated. The association between the frequency of trace proteinuria and incidence of 1.5-fold increase in serum creatinine levels and overt proteinuria was analyzed using Cox regression analysis. Trajectories of estimated glomerular filtration rate (eGFR) were compared using a mixed-effect model. RESULTS: Among 306,317 participants, 3188 and 17,461 developed a 1.5-fold increase in serum creatinine levels and new-onset overt proteinuria, respectively, during the median follow-up period of 36.2 months. The adjusted hazard ratio (HR) and 95% confidence interval (CI) for 1.5-fold increase in serum creatinine level in the TrUP 1/2 and TrUP 2/2 groups, compared to TrUP 0/2 group, were 1.23 (1.07-1.42) and 1.39 (1.01-1.92), respectively, and the adjusted HR (95% CI) for overt proteinuria were 2.94 (2.83-3.06) and 5.14 (4.80-5.51), respectively. The eGFR decline rates in the TrUP 1/2 and TrUP 2/2 groups were higher than that in the TrUP 0/2 group (p for interaction < 0.001). CONCLUSIONS: Trace proteinuria (detected via dipstick test) was associated with subsequent kidney function decline and overt proteinuria in the general population.

Elevated urinary angiotensinogen excretion links central and renal hemodynamic alterations.

Inappropriate activation of intrarenal renin-angiotensin system (RAS) may contribute to the pathogenesis of cardio-renal syndrome (CRS). We aimed to examine the cross-sectional associations of urinary angiotensinogen (AGT) excretion, a biomarker of intrarenal RAS activity, with central (aortic) and renal hemodynamic parameters in middle-aged and older adults, including patients with chronic kidney disease. Aortic and renal hemodynamic parameters were measured using applanation tonometry and duplex ultrasonography in 282 participants. Urinary AGT, liver-type fatty acid-binding protein (L-FABP), and plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels were measured for each participant. Multiple linear regression analyses demonstrated that urinary AGT levels were associated with aortic blood pressures, pulsatile measures of renal blood flow, plasma NT-proBNP and urinary L-FABP levels after adjusting for potential covariates, including age, sex, body mass index, estimated glomerular filtration rate (GFR), and medication use. Additionally, when classified based on GFR stages and urinary AGT levels, plasma NT-proBNP and urinary L-FABP levels increased in participants with lower GFR and higher AGT groups. Our findings suggest that urinary AGT excretion is a shared determinant of central (aortic) and renal hemodynamics in middle-aged and older adults, providing clinical evidence for the potential role of intrarenal RAS activity in the development of CRS.

Relationship between the lower limit of systolic blood pressure target and kidney function decline in advanced chronic kidney disease: an instrumental variable analysis from the REACH-J CKD cohort study.

Intensive antihypertensive treatment decreases cardiovascular disease and mortality risks in chronic kidney disease (CKD), whereas extremely low systolic blood pressure (SBP) is associated with worsening kidney function and poor prognosis. Although the SBP variation is particularly large in patients with CKD, the optimal lower limit of SBP target is unclear. In a nationwide, multicenter cohort study of patients with an estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m2, we evaluated the association between the eGFR slopes and the lower limit of SBP target at ≥110 mmHg using a linear mixed-effects model and an instrumental variable method. The instrumental variable was calculated as the facility-level percentage of nephrologists who answered in the survey that their lower limit of SBP target was 110 mmHg or higher. A total of 1320 patients (mean age 70 years; 66% men) were included. The mean eGFR slope ± standard deviation over the four years to baseline was -2.48 ± 2.15 mL/min/1.73 m2/year. The instrumental variable for the lower limit of SBP target at ≥110 mmHg (vs. ≤100 mmHg) was associated with less eGFR decline (coefficient: +1.05 mL/min/1.73 m2/year; 95% confidence interval: 0.33-1.77), while unassociated with a history of cardiovascular disease. The renoprotective effect was particularly larger in the subgroups of the elderly and those with a history of cardiovascular disease. In conclusion, the lower limit of SBP target at 110 mmHg or higher was associated with improved eGFR slope, suggesting the importance of aiming at avoiding excessively low SBP in patients with advanced CKD.