Published papers

Renin-angiotensin system inhibitors are recommended for treating hypertension with chronic kidney disease. The addition of a mineralocorticoid receptor blocker may be one option to achieve target blood pressure. We investigated the efficacy and safety of esaxerenone, a mineralocorticoid receptor blocker, in Japanese hypertensive patients with moderate kidney dysfunction. Two multicenter, open-label, nonrandomized dose escalation studies were conducted to investigate esaxerenone monotherapy and add-on therapy to renin-angiotensin system inhibitor treatment. Esaxerenone therapy was initiated at 1.25 mg/day and titrated to 2.5 and then 5 mg/day for a treatment duration of 12 weeks. Primary endpoints were changes from baseline in sitting systolic and diastolic blood pressure. Safety, pharmacokinetics, and urinary albumin-to-creatinine ratios were also assessed. Thirty-three patients received monotherapy, and 58 received add-on therapy; the mean baseline estimated glomerular filtration rates were 51.9 and 50.9 mL/min/1.73 m2, respectively. The esaxerenone dosage was increased to ≥2.5 mg/day in 100% (n = 33) and 93.1% (n = 54) of patients receiving monotherapy and add-on therapy, respectively. Reductions in sitting blood pressure from baseline to the end of treatment were similar (monotherapy: -18.5/-8.8 mmHg; add-on therapy: -17.8/-8.1 mmHg; both P < 0.001). The antihypertensive effects of esaxerenone were consistent across patient subgroups. A serum K+ level ≥5.5 mEq/L was observed in seven patients (12.1%) receiving add-on therapy but in none receiving monotherapy. All increases in serum K+ levels were transient, and no patient met predefined serum K+ level criteria for dose reduction or therapy discontinuation. No patient discontinued treatment owing to kidney function decline. Esaxerenone was effective and well tolerated in hypertensive patients with moderate kidney dysfunction.

The common histopathology of antineutrophil cytoplasmic antibody-associated vasculitis comprises pauci-immune crescentic glomerulonephritis with concomitant tubulointerstitial nephritis. Tubulointerstitial nephritis in the absence of glomerular involvement in patients with antineutrophil cytoplasmic antibody-associated vasculitis is uncommon. We report a case of antineutrophil cytoplasmic antibody-associated vasculitis-associated acute kidney injury manifesting as tubulointerstitial nephritis without glomerulonephritis. A 75-year-old woman with fever, cough, and myalgia developed kidney dysfunction with inflammatory reactions and tubular-type proteinuria, without glomerular hematuria. A kidney biopsy revealed tubulointerstitial nephritis with arteritis. We ruled out important underlying etiologies of tubulointerstitial nephritis, including infection, drug reactions, and autoimmune diseases. Since chest high-resolution computed tomography demonstrated mild interstitial pneumonia in bilateral lower lung fields, myeloperoxidase antineutrophil cytoplasmic antibody was measured and found to be positive. Therefore, we diagnosed the patient with antineutrophil cytoplasmic antibody-associated vasculitis-associated tubulointerstitial nephritis but not glomerulonephritis, and interstitial pneumonia. The patient's kidney function and symptoms markedly improved with prednisolone treatment. Clinicians should maintain high-level vigilance for antineutrophil cytoplasmic antibody-associated vasculitis as a possible underlying component of tubulointerstitial nephritis, particularly when kidney function deteriorates with tubulointerstitial injuries without glomerular features.

CONTEXT: The oversecretion of plasma aldosterone by unilateral aldosterone-producing adenoma (APA) can be cured by adrenalectomy. However, the time needed for the endocrine environment to normalize remains unclear. OBJECTIVE: To clarify adequate timing for a biochemical evaluation in unilateral APA patients after adrenalectomy. DESIGN AND PATIENTS: A total of 166 unilateral APA patients were retrospectively reviewed. We evaluated the plasma aldosterone concentration (PAC) (pg/mL), active renin concentration (ARC) (pg/mL), aldosterone-renin ratio (ARR; PAC/ARC), serum potassium concentration and estimated glomerular filtration rate (eGFR) at 1, 3 and 6 postoperation months (POM). RESULTS: PAC was significantly lower at 1POM than at presurgery (presurgery; 407.2, 1 POM; 90.0 pg/mL, P < .001). ARC did not increase from baseline at 1POM, but significantly increased at 3POM (presurgery; 4.43, 1POM; 4.87, 3POM; 11.3 pg/mL, P < .001). ARR significantly decreased at 1POM (presurgery; 146.9, 1 POM; 26.3, P < .001) although ARC did not increase at 1POM. Among the 34 patients who had hypokalaemia presurgery, it was resolved in 28 (82%) at 1POM and in all (100%) at 3POM. The biochemical outcomes at 1POM were 131 (79%) complete, 20 (12%) partial and 15 (9%) absent successes, while at 3POM, 147 (89%) were complete, 9 (5%) partial and 10 (6%) absent. Twenty-three (14%) patients were reclassified into different biochemical outcomes between 1 and 3POM, whereas only 5 (3%) changed between 3 and 6POM. CONCLUSION: The appropriate timing for a biochemical evaluation of unilateral APA patients treated with laparoscopic adrenalectomy appears to be 3 months or more after surgery.

Asperuloside (ASP) is an iridoid glycoside that is extracted from Eucommia leaves. Eucommia is used in traditional Chinese medicine and has a long history of benefits on health and longevity. Here, we investigated the impact of ASP on obesity-related metabolic disorders and show that ASP reduces body weight gain, glucose intolerance, and insulin resistance effectively in mice fed with a high-fat diet (HFD). Intestinal dysbiosis is closely linked with metabolic disorders. Our data indicate that ASP achieves these benefits on metabolic homeostasis by reversing HFD-induced gut dysbiosis and by changing gut-derived secondary metabolites and metabolic signaling. Our results indicate that ASP may be used to regulate gut microbiota for the treatment of obesity and type 2 diabetes.

The incidence of atrial fibrillation (AF) and risk of cardiovascular events are reportedly higher in patients with primary aldosteronism (PA) than essential hypertension. However, associated factors of comorbid AF and cardiovascular events in PA patients after PA treatment remain unclear. This nationwide registration study included PA patients ≥20 years old. Incident cardiovascular events were observed with a mean follow-up of approximately 3 years. A total of 3654 patients with PA were included at the time of analysis. Prevalence of AF was 2.4%. PA patients with AF were older, more frequently male and had longer duration of hypertension than those without AF. No significant difference in basal plasma and adrenal venous aldosterone concentration, renin activity, potassium concentration, confirmatory tests of PA, laterality or surgery rate were seen between groups. Logistic regression analysis showed age, male sex, cardiothoracic ratio, past history of coronary artery disease and heart failure were independent factors associated with AF. PA patients with AF showed a higher frequency of cardiovascular events than those without AF (P < 0.001). Multivariate Cox analyses demonstrated AF in addition to older age, duration of hypertension, body mass index and chronic kidney disease as independent prognostic factors for cardiovascular events after PA treatment. Incidence of cardiovascular events were significantly lower in PA patients with AF than AF patients from the Fushimi registry during follow-up after adjusting age, sex and systolic blood pressure. Early diagnosis of PA may prevent AF and other cardiovascular events in PA patients by shortening the duration of hypertension and appropriate PA treatment.

Primary aldosteronism causes renal structural damage after glomerular hyperfiltration, and primary aldosteronism-specific treatment leads to an acute fall in estimated glomerular filtration rate (eGFR). We investigated whether this change affected the long-term eGFR slope in a retrospective cohort from the multicenter Japan Primary Aldosteronism Study. We allocated patients with primary aldosteronism to the adrenalectomy (n=202) and MR (mineralocorticoid receptor) antagonist (n=303) groups based on their treatment history and analyzed the association between the initial eGFR fall and long-term eGFR slope. The increased age, low serum potassium levels, high eGFR, and high plasma aldosterone levels were independent predictors for a large initial eGFR fall in both groups. Our analysis of tertiles based on the initial eGFR fall revealed that in the MR antagonist group, patients with a small initial eGFR fall had a significantly steeper long-term eGFR slope than those with a large initial fall (tertile 1 versus 2, P=0.025; tertile 1 versus 3, P=0.017). These associations were not identified in the adrenalectomy group. Thus, the smaller the acute fall in eGFR by initiation of MR antagonists, the greater was the rate of long-term eGFR decline. While the acute fall in eGFR induced by primary aldosteronism-specific treatment is occasionally a clinical concern, our findings highlight the favorable implications of the acute fall with respect to long-term renal outcomes.

Deposition of visceral fat and insulin resistance play central role in the development of non-communicable diseases (NCDs) including obesity, hypertension and type 2 diabetes. However, we shed more light upon the intestines and the kidney as a strong driver of NCDs. Based upon unexpected outcomes of clinical trials using sodium-glucose cotransporter (SGLT) 2 inhibitors to demonstrate their actions for not only body weight reduction and blood glucose fall but also remarkable cardiorenal protection, we speculate that hyperfunction of the intestines and the kidney is one of critical contributing factors for initiation of NCDs. By detecting high amount of glucose and sodium chloride around them by sweet/salt taste sensors, the intestines and the kidney are designed to (re)absorb these nutrients by up-regulating SGLT1 or SGLT2. We designate these hyperfunctioning organs for nutrient uptake as "greedy organs". The greedy organs can induce NCDs ("greedy organ hypothesis"). SGLTs are regulated by glucose and sodium chloride, and SGLTs or other genes can be "greedy genes." Regulating factors for greedy organs are renin-angiotensin system, renal sympathetic nervous activity, gut inflammation/microbiota or oxidative stress. Mitigation of organ greediness by SGLT2 inhibitors, ketone bodies, bariatric surgery, and regular lifestyle to keep rhythmicity of biological clock are promising.

2型糖尿病644名を対象に、血清ビリルビン濃度、糖尿病性網膜症、大血管障害(脳卒中、虚血性心疾患、末梢動脈性疾患)の関連について検討した。網膜症の合併は42%、大血管障害の合併は34%にみられ、非合併例と比較して網膜症合併例では大血管障害の合併率が有意に高く、網膜症合併症例、大血管障害合併例では総ビリルビン濃度が有意に低かった。また、ロジスティック回帰分析では網膜症合併が大血管障害のリスク因子である可能性、低ビリルビン血症が網膜症、大血管障害の共通したリスク因子である可能性が示唆された。2型糖尿病患者において低ビリルビン血症は細小血管障害、大血管障害を有する患者を発見するためのバイオマーカーとして有用である可能性があること、ビリルビンは網膜症と大血管障害の両者に対して保護的な作用を発揮している可能性があることが示された。

OBJECTIVES: To combat global increases in the prevalence of lifestyle-related diseases and concomitant infectious diseases, we aimed to develop an innovative intranasal vaccine that simultaneously targets both hypertension and pneumonia, is not given by invasive injection, and offers prolonged therapeutic effect and reduced frequency of administration. METHODS: Angiotensin II type 1 receptor-pneumococcal surface protein A (AT1R-PspA) vaccine, consisting of a cationic nanometer-sized hydrogel incorporating AT1R partial peptide conjugated with PspA and cyclic diguanylate monophosphate adjuvant, was created and given intranasally to spontaneously hypertensive rats (SHRs). Antigen-specific antibodies and blood pressure were examined to evaluate immune responses and the antihypertensive effect of the vaccine. To examine the protective effect of antibodies induced by vaccination on pneumococcal infection, sera obtained from immunized SHRs were incubated with a lethal dose of Streptococcus pneumoniae and then administered to mice. RESULTS: Five doses of AT1R-PspA nasal-vaccine-induced AT1R-specific serum IgG antibody production and attenuated the development of hypertension in SHRs in the long term. Both in-vitro and in-vivo studies revealed that responses to angiotensin II were suppressed in vaccinated rats. Mice passively immunized with sera obtained from AT1R-PspA-vaccinated SHRs were protected from lethal pneumococcal infection. CONCLUSION: Intranasal immunization with AT1R-PspA vaccine has the potential to simultaneously attenuate the development of hypertension and protect from lethal pneumococcal infection.

Background: Low birthweight (LBW) is a worldwide public health problem, demonstrating an increasing incidence in developed countries, including Japan. LBW is also a risk factor for later development of chronic kidney disease (CKD). To date, studies have not evaluated the population impacts of increasing LBW rates on renal function. Methods: Estimated glomerular filtration rate (eGFR) was evaluated in 3737 Japanese adolescent males (15-16 years old) using annual cross-sectional data over an 18-year period (1998-2015). Results: Between the initial (1998-2003) and final (2010-15) periods of the study, the mean birthweight decreased from 3213.4 +/- 383.8 to 3116.2 +/- 382.3 g and the LBW rate increased from 2.5 to 5.5% (both P = 0.01). Additionally, the mean eGFR decreased from 105.1 +/- 15.9 to 97.4 +/- 13.8 mL/min/1.73 m 2 and the prevalence of mildly reduced renal function (eGFR </= 60- <90 mL/min/1.73 m 2 ) increased from 16.4 to 30.0% (both P </= 0.01), most evident in the LBW group (from 10.3 to 41.7%, P </=0.01). The prevalence of proteinuria also increased significantly. Mildly reduced renal function was significantly associated with LBW [odds ratio (LBW 3000-3999 g) 1.51; 95% confidence interval 1.00-2.55; P = 0.047]. Conclusions: . In this population of Japanese adolescents, the frequency of mildly reduced renal function increased as the LBW frequency increased. Our findings may have implications for the broader Japanese population as well as for other populations in which the prevalence of LBW is increasing.

© 2018 S. Karger AG, Basel. Nephronophthisis-related ciliopathies (NPHP-RC) are autosomal recessive disorders characterized by renal corticomedullary cysts with the extrarenal symptoms. Typically, patients with NPHP-RC reach end-stage kidney disease (ESKD) before the age of 30 years. We herein report a Japanese woman with NPHP-RC who had unusually delayed progression to ESKD after 6 decades. She exhibited liver dysfunction at the age of 23 years. She also showed mild renal dysfunction at the age of 43 years. Ultrasonography revealed bilateral multiple renal cysts with loss of corticomedullary differentiation. Her liver and renal functions gradually deteriorated. She was diagnosed with liver fibrosis as a result of biopsy, and initiated the maintenance hemodiafiltration therapy for ESKD at the age of 61 years. Because of a unique combination of multiple renal cysts and liver fibrosis, ciliopathy was suspected and medical exome analysis was performed. A novel homozygous missense mutation was identified in RPGRIP1L (c.1810G>A p.Glu604Lys), a causative gene for NPHP-RC. To the best of our knowledge, this patient is the oldest one who progressed to ESKD in NPHP-RC. Our case illustrates that NPHP-RC should be included in the differential diagnosis of the patient with corticomedullary polycystic kidneys accompanied by the extrarenal organ involvements, even if the patient is elderly.

© 2018 The Japanese Society of Hypertension. The (pro)renin receptor is important in the regulation of the tissue renin-angiotensin-aldosterone system. The benefits and safety of single-aliskiren treatment without other renin-angiotensin-aldosterone system inhibitors remain unclear. The serum level of the soluble form of the (pro)renin receptor is thought to be a biomarker reflecting the activity of the tissue renin-angiotensin-aldosterone system. We investigated the effects of single renin-angiotensin-aldosterone system blockade with aliskiren on renal and vascular functions and determined if serum level of the soluble (pro)renin receptor was a predictor of aliskiren efficacy in hypertensive patients with chronic kidney disease. Thirty-nine essential hypertensive patients with chronic kidney disease in our outpatient clinic were randomly assigned to receive either aliskiren or amlodipine. The parameters associated with renal and vascular functions and indices of renin-angiotensin-aldosterone system components, including serum levels of the soluble form, were evaluated before and after 12-week and 24-week treatment. Blood pressure was not significantly different between the groups. No significant changes in serum levels were observed in the soluble (pro)renin receptor in either group. Urinary albumin, protein excretion, and cardio-ankle vascular index significantly decreased in the aliskiren group. In the aliskiren group, there was a significant negative correlation between the basal level of the soluble (pro)renin receptor and the change in plasma aldosterone concentration. Single renin-angiotensin-aldosterone system blockade with aliskiren showed renal and vascular protective effects independent of blood pressure reduction. Serum levels of the soluble (pro)renin receptor may indicate aldosterone production via the (pro)renin receptor in the adrenal gland.

© 2018 The Author(s). Under diabetic conditions, sodium-glucose cotransporter 2 (SGLT2) for glucose uptake in proximal tubules (PTs) increases, whereas NAD+-dependent protein deacetylase silent mating type information regulation 2 homolog 1 (Sirtuin-1; SIRT1) for PT survival decreases. Therefore, we hypothesized that increased glucose influx by SGLT2 reduces SIRT1 expression. To test this hypothesis, db/db mice with diabetes and high-glucose (HG)-cultured porcine PT LLC-PK1 cells in a two-chamber system were treated with the SGLT2 inhibitor canagliflozin. We also examined SIRT1 and SGLT2 expression in human kidney biopsies. In db/db mice, SGLT2 expression increased with concomitant decreases in SIRT1, but was inhibited by canagliflozin. For determination of the polarity of SGLT2 and SIRT1 expression, LLC-PK1 cells were seeded into Transwell chambers (pore size, 0.4 μm; Becton Dickinson, Oxford, UK). HG medium was added to either or to both of the upper and lower chambers, which corresponded to the apical and basolateral sides of the cells, respectively. In this system, the lower chamber with HG showed increased SGLT2 and decreased SIRT1 expression. Canagliflozin reversed HG-induced SIRT1 downregulation. Gene silencing and inhibitors for glucose transporter 2 (GLUT2) blocked HG-induced SGLT2 expression upregulation. Gene silencing for the hepatic nuclear factor-1α (HNF-1α), whose nuclear translocation was enhanced by HG, blocked HG-induced SGLT2 expression upregulation. Similarly, gene silencing for importin-α1, a chaperone protein bound to GLUT2, blocked HG-induced HNF-1α nuclear translocation and SGLT2 expression upregulation. In human kidney, SIRT1 immunostaining was negatively correlated with SGLT2 immunostaining. Thus, under diabetic conditions, SIRT1 expression in PTs was downregulated by an increase in SGLT2 expression, which was stimulated by basolateral HG through activation of the GLUT2/importin-α1/HNF-1α pathway.