Early Clinical Experience of Finerenone in People with Chronic Kidney Disease and Type 2 Diabetes in Japan-A Multi-Cohort Study from the FOUNTAIN (FinerenOne mUltidatabase NeTwork for Evidence generAtIoN) Platform.

Background: In the phase 3 clinical trials FIGARO-DKD and FIDELIO-DKD, finerenone reduced the risk of cardiovascular and kidney events among people with chronic kidney disease (CKD) and type 2 diabetes (T2D). Evidence regarding finerenone use in real-world settings is limited. Methods: A retrospective cohort study (NCT06278207) using two Japanese nationwide hospital-based databases provided by Medical Data Vision (MDV) and Real World Data Co., Ltd. (RWD Co., Kyoto Japan), converted to the OMOP common data model, was conducted. Persons with CKD and T2D initiating finerenone from 1 July 2021, to 30 August 2023, were included. Baseline characteristics were described. The occurrence of hyperkalemia after finerenone initiation was assessed. Results: 1029 new users of finerenone were included (967 from MDV and 62 from RWD Co.). Mean age was 69.5 and 72.4 years with 27.3% and 27.4% being female in the MDV and RWD Co. databases, respectively. Hypertension (92 and 95%), hyperlipidemia (59 and 71%), and congestive heart failure (60 and 66%) were commonly observed comorbidities. At baseline, 80% of persons were prescribed angiotensin-converting-enzyme inhibitors or angiotensin-receptor blockers. Sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists were prescribed in 72% and 30% of the study population, respectively. The incidence proportions of hyperkalemia were 2.16 and 2.70 per 100 persons in the MDV and RWD Co. databases, respectively. There were no hospitalizations associated with hyperkalemia observed in either of the two datasets. Conclusions: For the first time, we report the largest current evidence on the clinical use of finerenone in real-world settings early after the drug authorization in Japan. This early evidence from clinical practice suggests that finerenone is used across comorbidities and comedications.

Clinical effect of nonsteroidal mineralocorticoid receptor (MR) antagonists in the treatment of diabetic kidney disease: expectations as a new therapeutic strategy.

Diabetes mellitus is the main cause of chronic kidney disease (CKD) in Japan and worldwide. Although angiotensin-converting enzyme (ACE) inhibitors and angiotensin II type 1 receptor blockers (ARBs) are basic drugs for the treatment of CKD with diabetes (diabetic kidney disease, DKD) with albuminuria and/or proteinuria, it has also become clear that the use of an ACE inhibitor or ARB alone is not fully sufficient. We have previously reported the clinical effects of mineralocorticoid receptor (MR) antagonists and recommended their use in addition to renin-angiotensin system inhibitors. Recently, new types of nonsteroidal MR antagonists have been developed, and the results of a large-scale study are expected. Nonsteroidal MR antagonists are distributed in the heart, lungs, liver, and kidneys when administered orally and are characterized by their equivalent distribution between the heart (nonepithelial tissue) and kidneys (epithelial tissue). We summarize the latest evidence regarding the use of nonsteroidal MR antagonists in the treatment of DKD. Hyperkalemia and renal dysfunction are frequent during MR antagonist treatment. However, with careful and combined monitoring of these two conditions, the effectiveness of MR antagonists will not be diminished; conversely, it is apparent that patients at such risk will benefit more from the addition of an MR antagonist to the treatment regimen. The most important measure against hyperkalemia is the regular monitoring of serum potassium levels and renal function. The safest and most reliable measure against hyperkalemia is the combined use of a new oral potassium adsorbent that has high potassium selectivity and few side effects. In DKD treatment, it is important to continue using MR antagonists without interruption as much as possible.

Methylation pattern of urinary DNA as a marker of kidney function decline in diabetes.

INTRODUCTION: Renal tubular injury contributes to the decline in kidney function in patients with diabetes. Cell type-specific DNA methylation patterns have been used to calculate proportions of particular cell types. In this study, we developed a method to detect renal tubular injury in patients with diabetes by detecting exfoliated tubular cells shed into the urine based on tubular cell-specific DNA methylation patterns. RESEARCH DESIGN AND METHODS: We identified DNA methylation patterns specific for human renal proximal tubular cells through compartment-specific methylome analysis. We next determined the methylation levels of proximal tubule-specific loci in urine sediment of patients with diabetes and analyzed correlation with clinical variables. RESULTS: We identified genomic loci in SMTNL2 and G6PC to be selectively unmethylated in human proximal tubular cells. The methylation levels of SMTNL2 and G6PC in urine sediment, deemed to reflect the proportion of exfoliated proximal tubular cells due to injury, correlated well with each other. Methylation levels of SMTNL2 in urine sediment significantly correlated with the annual decline in estimated glomerular filtration rate. Moreover, addition of urinary SMTNL2 methylation to a model containing known risk factors significantly improved discrimination of patients with diabetes with faster estimated glomerular filtration rate decline. CONCLUSIONS: This study demonstrates that patients with diabetes with continual loss in kidney function may be stratified by a specific DNA methylation signature through epigenetic urinalysis and provides further evidence at the level of exfoliated cells in the urine that injury of proximal tubular cells may contribute to pathogenesis of diabetic kidney disease.

Does the temporary decrease in the estimated glomerular filtration rate (eGFR) after initiation of mineralocorticoid receptor (MR) antagonist treatment lead to a long-term renal protective effect?

Recently, deleterious effects of aldosterone on the kidney via mineralocorticoid receptors (MRs) have been noted. MR antagonists have been reported to show significant antialbuminuric effects when added to angiotensin-converting enzyme inhibitors or angiotensin II type 1 receptor blockers. However, a decrease in the estimated glomerular filtration rate (eGFR) has been reported during MR antagonist treatment. On the other hand, although the eGFR often decreases, significant reductions in total mortality and cardiovascular events have been observed in large-scale clinical trials in patients with chronic heart failure. What are the implications of the changes in eGFR due to MR antagonist treatment? Glomerular hyperfiltration has been reported to occur with an aldosterone excess, and it can be seen that relative glomerular hyperfiltration is rapidly corrected with MR antagonism, even without aldosterone excess. This is reflected in the initial temporary decrease in the eGFR. After MR antagonist treatment, eGFR decreases temporarily, and it appears that renal function has deteriorated. However, if renal function has actually deteriorated, a reduction in all-cause and cardiovascular death is unlikely to occur in the clinical studies in patients with chronic heart failure. That is, the initial transient decrease in eGFR by the MR antagonist appears to work effectively to provide fine adjustment of glomerular pressure, and this approach works advantageously to suppress long-term cardiovascular events. It is expected that a number of long-term, large-scale clinical research trials targeting renal events and all-cause and cardiovascular death in CKD patients treated with an MR antagonist will be planned.

A prospective study of frequency and characteristics of cough during ACE inhibitor treatment.

Angiotensin converting enzyme (ACE) inhibitors are reportedly effective, and positively indicated in patients with chronic heart failure with decreased contractility, after myocardial infarction, after cerebrovascular disorders, and in those with chronic kidney disease. However, the biggest challenge to continuous use of ACE inhibitors is the adverse reaction of cough. Accordingly, in the present study, we investigated the present state and characteristics of ACE inhibitor-induced cough in patients with essential hypertension currently being treated with an ACE inhibitor for an average of 18 months, who could be regularly checked for cough. Subjects in this study were 176 patients overall (mean age 67 ± 11 years old), 90 men and 86 women. The adverse reaction of cough was observed in 20% of patients, and more frequently in women than in men. However, in 26 of the patients with cough, the cough either resolved naturally or completely disappeared while the treatment continued, after which patients could continue taking the medication. Specifically, ACE inhibitor treatment was eventually discontinued due to cough in 5.1% of patients. Cough occurred less frequently with concomitant calcium antagonists or diuretics than with ACE inhibitor monotherapy. Cough as an adverse reaction occurred at a low frequency when medication was taken at bedtime. We considered a number of measures to counteract cough, then in addition to starting the ACE inhibitor treatment as early as possible, it is important to devise ways for the ACE inhibitor treatment to be continued for as long as possible, through the adept use of these measures.

The necessity and effectiveness of mineralocorticoid receptor antagonist in the treatment of diabetic nephropathy.

Diabetes mellitus is a major cause of chronic kidney disease (CKD), and diabetic nephropathy is the most common primary disease necessitating dialysis treatment in the world including Japan. Major guidelines for treatment of hypertension in Japan, the United States and Europe recommend the use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers, which suppress the renin-angiotensin system (RAS), as the antihypertensive drugs of first choice in patients with coexisting diabetes. However, even with the administration of RAS inhibitors, failure to achieve adequate anti-albuminuric, renoprotective effects and a reduction in cardiovascular events has also been reported. Inadequate blockade of aldosterone may be one of the reasons why long-term administration of RAS inhibitors may not be sufficiently effective in patients with diabetic nephropathy. This review focuses on treatment in diabetic nephropathy and discusses the significance of aldosterone blockade. In pre-nephropathy without overt nephropathy, a mineralocorticoid receptor antagonist can be used to enhance the blood pressure-lowering effects of RAS inhibitors, improve insulin resistance and prevent clinical progression of nephropathy. In CKD categories A2 and A3, the addition of a mineralocorticoid receptor antagonist to an RAS inhibitor can help to maintain 'long-term' antiproteinuric and anti-albuminuric effects. However, in category G3a and higher, sufficient attention must be paid to hyperkalemia. Mineralocorticoid receptor antagonists are not currently recommended as standard treatment in diabetic nephropathy. However, many studies have shown promise of better renoprotective effects if mineralocorticoid receptor antagonists are appropriately used.

Effect of aldosterone breakthrough on albuminuria during treatment with a direct renin inhibitor and combined effect with a mineralocorticoid receptor antagonist.

We have reported observing aldosterone breakthrough in the course of relatively long-term treatment with renin-angiotensin (RA) system inhibitors, where the plasma aldosterone concentration (PAC) increased following an initial decrease. Aldosterone breakthrough has the potential to eliminate the organ-protective effects of RA system inhibitors. We therefore conducted a study in essential hypertensive patients to determine whether aldosterone breakthrough occurred during treatment with the direct renin inhibitor (DRI) aliskiren and to ascertain its clinical significance. The study included 40 essential hypertensive patients (18 men and 22 women) who had been treated for 12 months with aliskiren. Aliskiren significantly decreased blood pressure and plasma renin activity (PRA). The PAC was also decreased significantly at 3 and 6 months; however, the significant difference disappeared after 12 months. Aldosterone breakthrough was observed in 22 of the subjects (55%). Urinary albumin excretion differed depending on whether breakthrough occurred. For the subjects in whom aldosterone breakthrough was observed, eplerenone was added. A significant decrease in urinary albumin excretion was observed after 1 month, independent of changes in blood pressure. In conclusion, this study demonstrated that aldosterone breakthrough occurs in some patients undergoing DRI therapy. Aldosterone breakthrough affects the drug's ability to improve urinary albumin excretion, and combining a mineralocorticoid receptor antagonist with the DRI may be useful for decreasing urinary albumin excretion. When the objective is organ protection in hypertensive patients, a two-pronged approach using combination therapy to inhibit both the RA system and aldosterone may be highly effective.

Mineralocorticoid receptor antagonists: their use and differentiation in Japan.

In the presence of salt, aldosterone causes hypertension and organ damage via the mineralocorticoid receptor (MR) through various mechanisms. MR antagonists are considered to be potassium-sparing diuretics that exert their effect by blocking MR in the kidney, and they are not the first choice for treating hypertension. However, the importance and usefulness of inhibiting aldosterone in the management of hypertension have recently been revealed in both the basic and clinical fields. In Japan, both the selective MR antagonist eplerenone and the non-selective MR antagonist spironolactone are indicated for the treatment of hypertension. Although these drugs are generally used in the same manner, in some cases they require differentiation. This differentiation is divided into two types due to the differences in their features and differences in their contraindications in Japan. Based on a number of studies on MR antagonists that have been recently published, the diseases and clinical conditions targeted by MR antagonists appear to be likely to increase in the future. In Japan, we consider it necessary to carefully differentiate spironolactone from eplerenone in regard to their intended uses.

Combination therapy with aldosterone blockade and renin-angiotensin inhibitors confers organ protection.

There is increasing evidence that aldosterone exerts major adverse cardiovascular effects through classical mineralocorticoid receptors (MR) in nonepithelial tissues such as the brain and heart. This nonepithelial role of aldosterone has been underscored by the recent Randomized Aldactone Evaluation Study (RALES) and the Eplerenone Post-AMI Heart Failure Efficacy and Survival Study (EPHESUS). These studies also showed that when using MR antagonist as an "organ protecting" drug, further organ protection could be derived by the addition of an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II type 1 receptor blocker (ARB). The long-term effect of aldosterone was not inhibited in some subjects, so the possibility of organ damage due to so-called "breakthrough" aldosterone cannot be ignored. Nonepithelial MR-mediated effects played a major role in this aldosterone effect. These effects can be inhibited by MR antagonist at a small dose, not lower blood pressure. Therefore, the idea is now to combine a small dose of MR antagonist with an ACE inhibitor or ARB. However, warnings have been given recently due to the emergence of hyperkalemia and other adverse effects associated with inappropriate combination therapy. It is important to note that, if the eligibility criteria of RALES and EPHESUS are fulfilled, the potassium level will rarely become problematic. Therefore, the recent increase in the incidence of adverse effects can be attributed to the incorrect application of combination therapy. Elderly patients or those with dehydration, renal dysfunction, and aggravated heart failure require further close monitoring or termination of spironolactone administration. The combination of an MR antagonist and renin-angiotensin inhibitors should be a useful strategy if subjects are carefully selected, and carefully monitored. Adverse effects will occur only if the usage recommendations based on previous researches are not followed.

Antiproteinuric effects of mineralocorticoid receptor blockade in patients with chronic renal disease.

We have recently shown that mineralocorticoid receptor blockade may represent optimal therapy for patients with early diabetic nephropathy who show aldosterone breakthrough during angiotensin-converting enzyme (ACE) inhibitor treatment, and who no longer show the maximal antiproteinuric effects of ACE inhibition. In this study, we explored the effects of the mineralocorticoid receptor antagonist spironolactone on urinary protein excretion in patients with chronic renal disease with proteinuria persistently more than 0.5 g/d, despite maintained blood pressure (BP) control, and including the use of an ACE inhibitor (trandolapril) for at least 10 months. After a 12-week study period of spironolactone treatment (25 mg/d), BP did not change but urinary protein excretion was significantly reduced. The extent of the reduction was on average significantly greater in diabetic patients than in nondiabetics. In patients with diabetic nephropathy, although urinary type IV collagen did not decrease after conventional treatment, it was significantly reduced by spironolactone. None of the patients developed serious hyperkalemia, and no other adverse events were observed. All patients in this study had relatively well preserved renal function. In conclusion, the present study demonstrates that in patients with chronic renal disease with proteinuria persistently more than 0.5 g/d, despite BP control and the use of an ACE inhibitor, adding spironolactone to the conventional treatment produces beneficial effects on urinary protein excretion, particularly in patients with diabetes. Our study suggests that attenuation of mineralocorticoid receptor-mediated effects may become a new goal for patients who escape the antiproteinuric effects of the conventional treatment. Additional, larger, prospective, randomized double-blind studies will be needed for general acceptance of this strategy.

Aldosterone-induced organ damage: plasma aldosterone level and inappropriate salt status.

In recent years, it has been clarified that aldosterone can directly damage various organs, such as the heart, blood vessel, and kidneys, via non-epithelial mineralocorticoid receptors, independent of changes in blood pressure. Anti-aldosterone drugs have been clinically reported to be useful for their organ-protecting effects. The fact that these effects have been considered important for almost 10 years seems to indicate that aldosterone-induced organ damage can develop as a consequence of plasma aldosterone levels being in disproportion to salt status. In a previous study, cardiac fibrosis could not be induced in an experimental model of hyperaldosteronism with a low-salt diet. It is, therefore, extremely important to understand the relationship between plasma aldosterone level and inappropriate salt balance when considering diseases or states for which an anti-aldosterone drug is called for. In this paper we review the fundamental and clinical studies reported to date, mainly to investigate the pathology of organ damage induced by aldosterone and excess salt. Aldosterone-induced direct organ damage mediated through vasculitis essentially requires salt, which is inappropriate for plasma aldosterone level, and studies performed from this standpoint may provide a clue to the clarification of the involvement of salt in the actions of aldosterone via non-epithelial mineralocorticoid receptors. In humans, it is also strongly suggested that organ damage may occur, even at a plasma aldosterone level within a normal range, if salt intake is imbalanced to the aldosterone level. This means that the new aldosterone blocker eplerenone may also have significance as a drug inhibiting inflammation, possibly serving as a trigger of organ damage.

Aldosterone antagonist facilitates the cardioprotective effects of angiotensin receptor blockers in hypertensive rats.

BACKGROUND: There is increasing evidence to support the importance of blocking aldosterone to prevent target-organ damage in hypertension. We recently demonstrated an aldosterone breakthrough phenomenon during administration of an angiotensin type 1 receptor blocker (ARB). OBJECTIVE: To elucidate the pathophysiological significance of residual aldosterone by investigating the influence of the aldosterone antagonist on the cardioprotective effects of the ARB in hypertensive rats. METHODS: Injection vehicle alone, ARB (1.0 mg/kg per day candesartan by mouth), aldosterone antagonist (10 mg/kg per day spironolactone, subcutaneously), or combined treatment were administered to male stroke-prone spontaneously hypertensive rats for 24 weeks from the age of 4 weeks. Blood pressure, plasma angiotensin II and aldosterone concentrations, left ventricular weight, expression of type I and type III collagen mRNA, and histological findings were determined. RESULTS: In the ARB-treated group, aldosterone concentrations remained unchanged (1.10 +/- 0.20 nmol/l, compared with 1.17 +/- 0.46 nmol/l in the control group), whereas systolic blood pressure (178 +/- 9 mmHg), left ventricular weight (0.372 +/- 0.035 g/100 g body weight), expression of collagen mRNA, and cardiac interstitial and perivascular fibrosis all decreased significantly compared with the control group (systolic blood pressure: 222 +/- 10 mmHg, P < 0.05; left ventricular weight: 0.483 +/- 0.021 g/100 g body weight, P < 0.05). Although blood pressure (217 +/- 9 mmHg) and left ventricular weight (0.467 +/- 0.027 g/100 g body weight) remained unchanged in the group receiving spironolactone, the expression of both types of collagen mRNA and cardiac interstitial and perivascular fibrosis showed a significant decrease compared with the vehicle-treated group. In the rats receiving combined treatment with the ARB and spironolactone, left ventricular weight (0.352 +/- 0.005 g/100 g body weight, P < 0.05), expression of collagen mRNA, and cardiac interstitial and perivascular fibrosis all showed a further improvement compared with both the ARB and spironolactone groups. CONCLUSIONS: These results demonstrate that residual aldosterone has a significant impact on target-organ damage in hypertension, even during chronic administration of an ARB. The addition of an aldosterone antagonist has an advantage in facilitating the cardioprotective effects of ARBs.

Effects of the angiotensin II type 1 receptor antagonist candesartan, compared with angiotensin-converting enzyme inhibitors, on the urinary excretion of albumin and type IV collagen in patients with diabetic nephropathy.

BACKGROUND: We previously reported that the angiotensin II type 1 receptor antagonist candesartan was effective in reducing blood pressure and microalbuminuria in hypertensive patients with diabetic nephropathy after angiotensin-converting enzyme (ACE) inhibitors were replaced due to side effects. In the present study, the clinical effects of candesartan were investigated and compared with ACE inhibitors in patients with stage 2 or 3A diabetic nephropathy, mainly with respect to the effects on the urinary excretion of albumin and type IV collagen. METHODS: Forty-nine patients (26 males/23 females) with diabetic nephropathy (stage 2 or 3A), including normotensive patients, were the study subjects. The patients were treated with either an ACE inhibitor (23 patients) or candesartan (26 patients) for 11 +/- 3 months. The urinary excretion of albumin and urinary type IV collagen was measured. RESULTS: Posttreatment blood pressure tended to decrease, but such a decrease did not reach a statistically significant level, nor did it show any intergroup difference. The urinary albumin excretion was positively correlated with pretreatment mean blood pressure and left ventricular mass index, but the urinary type IV collagen excretion did not show such correlations. The urinary albumin excretion decreased significantly after treatment to a similar extent in both groups, whereas the urinary type IV collagen excretion decreased significantly only in the candesartan group. CONCLUSION: It was revealed that ACE inhibitors and candesartan reduced urinary albumin excretion to a similar extent in patients with diabetic nephropathy. From the results of the present study, it is inferred that the renoprotective effect of candesartan in diabetic nephropathy may partially differ from that of ACE inhibitors.

Aldosterone breakthrough during angiotensin-converting enzyme inhibitor therapy.

The effectiveness of angiotensin-converting enzyme (ACE) inhibitors in the treatment of cardiac diseases after infarction and heart failure, and of renal disease such as diabetic nephropathy, has been reported from recent large-scale clinical trials on ACE inhibitors. However, effects of ACE inhibitors during long-term therapy have not always been optimal. In recent years, aldosterone breakthrough has been suggested as a factor potentially involved, in that aldosterone levels may not remain suppressed when an ACE inhibitor is given for a relatively long time, with circulating aldosterone concentrations perhaps increasing above pretreatment levels. To improve our understanding of aldosterone-induced organ damage, which has attracted much attention in recent years, we summarize the data on aldosterone breakthrough during ACE inhibitor treatment in various diseases, and then we consider the mechanism and clinical significance of aldosterone breakthrough. Given the wide range of indications for ACE inhibitors, further studies should be designed to examine in which diseases and for which types of patients aldosterone blockade will be indicated. At present, the mechanisms of aldosterone breakthrough remain obscure, requiring further studies, including those on regional nonepithelial effects of aldosterone.

Effectiveness of aldosterone blockade in patients with diabetic nephropathy.

It has been reported that continuous ACE inhibitor therapy does not necessarily produce a maintained decrease in plasma aldosterone levels, which may remain high or increase eventually during long-term use (aldosterone escape). We have examined the role of aldosterone escape in 45 patients with type 2 diabetes and early nephropathy treated with an ACE inhibitor for 40 weeks. With treatment, there was a 40% reduction in average urinary albumin excretion, although urinary albumin excretion in patients with aldosterone escape (18 patients) was significantly higher than that in patients without escape (27 patients). In the 18 patients with escape, spironolactone (25 mg/d) was added to ACE inhibitor treatment in 13. After a 24-week study period, urinary albumin excretion and left ventricular mass index were significantly reduced without blood pressure change. In conclusion, the present study demonstrates that aldosterone escape is observed in 40% of patients with type 2 diabetes with early nephropathy despite the use of ACE inhibitors. Our study suggests the possibility that aldosterone blockade may represent optimal therapy for patients with early diabetic nephropathy who show aldosterone escape during ACE inhibitor treatment and who no longer show maximal antiproteinuric effects of ACE inhibition. Additional, larger, prospectively randomized, double-blind studies will be needed before adaptation of this strategy.

Relative long-term effects of spironolactone in conjunction with an angiotensin-converting enzyme inhibitor on left ventricular mass and diastolic function in patients with essential hypertension.

It has been reported that treatment with an angiotensin-converting enzyme (ACE) inhibitor is not adequate to suppress aldosterone, and we previously demonstrated that adding spironolactone to an ACE inhibitor may have beneficial effects on left ventricular hypertrophy (LVH) in selected patients with essential hypertension (EH). We have extended our previous short-term study, and addressed the relative long-term clinical effects of spironolactone and an ACE inhibitor in patients with EH who have LVH. Twenty patients with EH and concomitant LVH participated in this study. Subjects were treated with either an ACE inhibitor alone (group 1: 10 patients) or an ACE inhibitor plus spironolactone at the dose of 25 mg (group 2: 10 patients) for 60 weeks. The baseline clinical and echocardiographic characteristics of the two groups were similar. Final values of blood pressure were also similar between the two groups. The LV mass index (LVMI) decreased significantly in both groups, but the extent of reduction was significantly greater in group 2 at 60 weeks. The early peak to atrial peak filling velosities ratio (E/A ratio) was significantly increased to a similar extent in both groups. Serum procollagen type III amino-terminal peptide (PIIINP) was significantly decreased in group 2, but not in group 1. In group 2, there was a statistically significant correlation between the changes in LVMI and PIIINP. In conclusion, adding spironolactone to therapy with an ACE inhibitor for 60 weeks may have beneficial effects in patients with EH and concomitant LVH. Our study strongly suggests the possibility that attenuation of the effects of cardiac aldosterone in patients with EH by treatment with spironolactone and an ACE inhibitor may become a new goal for the prevention and regression of cardiac hypertrophy.

[Significance of combining spironolactone during long-term administration of ARB].

Blocking aldosterone action has been of clinical interest in the treatment of hypertension and related target organ damage. Although we have previously demonstrated aldosterone escape during long term administration of AT1 antagonist, pathological significance of aldosterone remains unknown. We investigated the effects of co-administration of spironolactone(SPRL) on the cardioprotective effects of AT1A in SHR-SP. Administration of AT1A alone resulted in a significant decrease in cardiac weight, cardiac transverse section area, cardiac fibrosis, and mRNA expression of BNP, type I and type III collagen, while cardiac ET-1 mRNA showed a significant increase. Co-administration of AT1A with SPRL resulted in a significant decrease in all the parameters including ET-1 mRNA expression. These results provide theoretical rationale for combination therapy of AT1A and SPRL in hypertension.

Aldosterone breakthrough during angiotensin II receptor antagonist therapy in stroke-prone spontaneously hypertensive rats.

Aldosterone breakthrough during ACE inhibitor therapy has been reported. This study investigates changes in plasma aldosterone concentration (PAC) and its mechanism and effects on target organ damage during long-term angiotensin II type 1 (AT1) receptor antagonist (AT1A) therapy in hypertensive rats. An AT1A (candesartan, 1 mg/kg per day PO) was administered in stroke-prone spontaneously hypertensive rats from 4 weeks of age for 34 weeks. PAC was significantly decreased during the first 4 weeks but showed aldosterone breakthrough after 8 weeks of AT1A administration. Plasma angiotensin II concentration was significantly elevated, whereas no change was seen in plasma ACTH or serum potassium. The mechanism(s) of aldosterone breakthrough were investigated by giving high doses of candesartan (3 mg/kg per day PO), dexamethasone (200 microg/kg per day IP), or the AT2 antagonist (PD123319, 10 mg/kg per day SC) during the last week of the 24-week AT1A treatment period. Dexamethasone and AT2 antagonist but not high-dose AT1A produced a significant decrease in PAC, with a larger decrease produced by the AT2 antagonist. To clarify the effects of the residual aldosterone, effects of coadministration of low-dose spironolactone (10 mg/kg per day SC), an aldosterone antagonist, on left ventricular hypertrophy and expression of brain natriuretic peptide mRNA were determined. Low-dose spironolactone further improved left ventricular hypertrophy and brain natriuretic peptide mRNA expression despite no additional depressor effect. These results suggest that aldosterone breakthrough occurs during long-term AT1A therapy, mainly by an AT2-dependent mechanism. Residual aldosterone may attenuate the cardioprotective effects of AT1A.