Impact of combined losartan/hydrochlorothiazide on proteinuria in patients with chronic kidney disease and hypertension

Thiazide and thiazide-like diuretics are associated with improved cardiovascular and renal outcomes in patients with chronic kidney disease

Introduction

Hypervolemia is a prevalent comorbidity of chronic kidney disease (CKD) patients. Thiazide diuretics (THZ) are the most common treatment for volume overload and hypertension (HTN). This study examines the association between THZ usage and clinical outcomes among CKD patients in a nationwide cohort.

Method

The total number of patients in the study was 24,312. After matching with one non-user randomly selected from the CKD population, we identified 8501 patients in the THZ and the comparison cohorts. Cox proportional hazards regression analysis was conducted to estimate the associations of THZ on the incidence of all-cause mortality, end-stage renal disease (ESRD), congestive heart failure (CHF), acute myocardial infarction (AMI), peripheral arterial occlusive disease (PAOD), and stroke.

Results

The all-cause mortality rate was significantly lower in THZ users than in non-users (hazard ratio [HR] = 0.65, 95% confidence interval [CI] = 0.60- 0.71). The THZ usage was associated with a lower incidence of ESRD, AMI, PAOD, and stroke (P<0.05). In subgroup analysis, some significant clinical outcomes were related with CKD stages 3 and 4 (P<0.05); however, there were no clinical associations in CKD stage 5. In further THZ subtype analysis, there were clinical associations with fewer deaths, ESRD, AMI, and PAOD accompanying chlorthalidone treatment. Moreover, the indapamide prescription was linked to lower mortality, ESRD, AMI, and PAOD prevalence. However, there were significantly greater incidences of ESRD, CHF, and AMI in the metolazone users.

Conclusion

THZ usage is associated with lower mortality and incidence of ESRD, AMI, PAOD, and stroke s in patients with CKD stages 3 and 4.

Recent Advances in the Emerging Therapeutic Strategies for Diabetic Kidney Diseases

Diabetic kidney disease (DKD) is one of the most common causes of end-stage renal disease worldwide. The treatment of DKD is strongly associated with clinical outcomes in patients with diabetes mellitus. Traditional therapeutic strategies focus on the control of major risk factors, such as blood glucose, blood lipids, and blood pressure. Renin–angiotensin–aldosterone system inhibitors have been the main therapeutic measures in the past, but the emergence of sodium–glucose cotransporter 2 inhibitors, incretin mimetics, and endothelin-1 receptor antagonists has provided more options for the management of DKD. Simultaneously, with advances in research on the pathogenesis of DKD, some new therapies targeting renal inflammation, fibrosis, and oxidative stress have gradually entered clinical application. In addition, some recently discovered therapeutic targets and signaling pathways, mainly in preclinical and early clinical trial stages, are expected to provide benefits for patients with DKD in the future. This review summarizes the traditional treatments and emerging management options for DKD, demonstrating recent advances in the therapeutic strategies for DKD.

The Forgotten Antiproteinuric Properties of Diuretics

BACKGROUND

Although diuretics are one of the most widely used drugs by nephrologists, their antiproteinuric properties are not generally taken into consideration.

SUMMARY

Thiazide diuretics have been shown to reduce proteinuria by >35% in several prospective controlled studies, and these values are markedly increased when combined with a low-salt diet. Thiazide-like diuretics (indapamide and chlorthalidone) have shown similar effectiveness. The antiproteinuric effect of mineralocorticoid receptor antagonists (spironolactone, eplerenone, and finerenone) has been clearly established through prospective and controlled studies, and treatment with finerenone reduces the risk of chronic kidney disease progression in type-2 diabetic patients. The efficacy of other diuretics such as amiloride, triamterene, acetazolamide, or loop diuretics has been less explored, but different investigations suggest that they might share the same antiproteinuric properties of other diuretics that should be evaluated through controlled studies. Although the inclusion of sodium-glucose cotransporter-2 inhibitors (SGLT2i) among diuretics is a controversial issue, their renoprotective and cardioprotective properties, confirmed in various landmark trials, constitute a true revolution in the treatment of patients with kidney disease. Recent subanalyses of these trials have shown that the early antiproteinuric effect induced by SGLT2i predicts long-term preservation of kidney function. Key Message: Whether the early reduction in proteinuria induced by diuretics other than finerenone and SGLT2i, as summarized in this review, also translates into long-term renoprotection requires further prospective and observational studies. In any case, it is important for the clinician to be aware of the antiproteinuric properties of drugs so often used in daily clinical practice.

Stronger Effect of Azilsartan on Reduction of Proteinuria Compared to Candesartan in Patients with CKD: A Randomized Crossover Trial

INTRODUCTION

Angiotensin receptor blockers (ARBs) are preferably used in hypertensive patients with CKD. Azilsartan is a strong antihypertensive ARB, but its antiproteinuric effects are not well understood. We compared the antiproteinuric effect of azilsartan and candesartan in CKD patients in an open-label, randomized, crossover trial.

METHODS

A total of 111 patients were treated with 20 mg of azilsartan daily for 2 months as a run-in period. After the run-in period, patients were randomized into 2 arms and received either 20 mg of azilsartan or 8 mg of candesartan daily for 3 months in a crossover trial. The primary outcome was the percent change in urinary protein-to-Cr ratio (UPCR).

RESULTS

Ninety-five patients completed the trial. The mean age was 64.3 years. The estimated glomerular filtration rate (eGFR) and UPCR were 41.5 mL/min/1.73 m2 and 1.8 g/gCr, respectively. The baseline systolic and diastolic blood pressures were 131.4 and 71.0 mm Hg, respectively. The mean percent change in the UPCR was -3.8% in the azilsartan group and 30.8% in the candesartan group at the 1st endpoint (p = 0.0004), and 6.1% in the azilsartan group and 25.8% in the candesartan group at the 2nd (final) endpoint (p = 0.029). The incidence of adverse events, including eGFR levels and serum potassium levels, was not significantly different between the groups.

CONCLUSION

A 20 mg azilsartan dose had potent antiproteinuric effects compared with an 8 mg candesartan dose, without an increase in adverse events. Azilsartan may provide renal protection in addition to antihypertensive effects in CKD patients.

A Randomized Trial of Distal Diuretics versus Dietary Sodium Restriction for Hypertension in Chronic Kidney Disease

BACKGROUND

Distal diuretics are considered less effective than loop diuretics in CKD. However, data to support this perception are limited.

METHODS

To investigate whether distal diuretics are noninferior to dietary sodium restriction in reducing BP in patients with CKD stage G3 or G4 and hypertension, we conducted a 6-week, randomized, open-label crossover trial comparing amiloride/hydrochlorothiazide (5 mg/50 mg daily) with dietary sodium restriction (60 mmol per day). Antihypertension medication was discontinued for a 2-week period before randomization. We analyzed effects on BP, kidney function, and fluid balance and related this to renal clearance of diuretics.

RESULTS

A total of 26 patients (with a mean eGFR of 39 ml/min per 1.73 m²) completed both treatments. Dietary sodium restriction reduced sodium excretion from 160 to 64 mmol per day. Diuretics produced a greater reduction in 24-hour systolic BP (SBP; from 138 to 124 mm Hg) compared with sodium restriction (from 134 to 129 mm Hg), as well as a significantly greater effect on extracellular water, eGFR, plasma renin, and aldosterone. Both interventions resulted in a similar decrease in body weight and NT-proBNP. Neither approaches decreased albuminuria significantly, whereas diuretics did significantly reduce urinary angiotensinogen and β2-microglobulin excretion. Although lower eGFR and higher plasma indoxyl sulfate correlated with lower diuretic clearance, the diuretic effects on body weight and BP at lower eGFR were maintained. During diuretic treatment, higher PGE2 excretion correlated with lower free water clearance, and four patients developed mild hyponatremia.

CONCLUSIONS

Distal diuretics are noninferior to dietary sodium restriction in reducing BP and extracellular volume in CKD. Diuretic sensitivity in CKD is maintained despite lower diuretic clearance.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

DD-study: Diet or Diuretics for Salt-sensitivity in Chronic Kidney Disease (DD), NCT02875886.

Antihypertensive therapy and adequacy of blood pressure control among adult hypertensive diabetic patients with chronic kidney disease in a tertiary referral hospital

Background: Tight blood pressure control retards the development of end-stage renal disease in hypertensive diabetic patients with chronic kidney disease. There is limited literature on blood pressure control among this patient population in a resource-limited setting. Research design and methods: A tertiary hospital-based cross-sectional study with 237 hypertensive diabetic patients with chronic kidney disease was conducted. A pre-tested questionnaire was used to assess patients' awareness of their ideal blood pressure. Data on blood pressure readings and antihypertensive therapies were abstracted into predesigned data collection forms and analyzed using STATA software version 13.0. Results: The participants' mean age was 61.8 ± 12.7 years and 106 (44.7%) patients were aware of the blood pressure targets. Adequate blood pressure control was found in 30.8%. Most (58.7%) were using ≥ 3 antihypertensive drug classes. Calcium channel blockers (51.1%), with principally amlodipine (26.2%) and nifedipine (24.1%), were the most preferred agents. Bivariate analysis showed enalapril (p = 0.009) and nifedipine (p = 0.022) being associated with adequate blood pressure control. However, nifedipine (AOR 2.79; 95% CI: 1.12-6.9, p = 0.028) and awareness of ideal blood pressure targets (AOR 4.57; 95% CI: 1.25-16.7, p = 0.022) were independent predictors of good control. Conclusion: Adequacy of blood pressure among hypertensive diabetic patients with chronic kidney disease is low and may be attributable to unawareness of its target level and using inappropriate therapy. Future studies should correlate level of blood pressure control with patient-, clinician-, and hospital-related factors.

A Novel Aldosterone Antagonist Limits Renal Injury in 5/6 Nephrectomy

Aldosterone antagonists slow the progression of chronic kidney disease (CKD), but their use is limited by hyperkalemia, especially when associated with RAS inhibitors. We examined the renoprotective effects of Ly, a novel non-steroidal mineralocorticoid receptor (MR) blocker, through two experimental protocols: In Protocol 1, male Munich-Wistar rats underwent 5/6 renal ablation (Nx), being divided into: Nx+V, receiving vehicle, Nx+Eple, given eplerenone, 150 mg/kg/day, and Nx+Ly, given Ly, 20 mg/kg/day. A group of untreated sham-operated rats was also studied. Ly markedly raised plasma renin activity (PRA) and aldosterone, and exerted more effective anti-albuminuric and renoprotective action than eplerenone. In Protocol 2, Nx rats remained untreated until Day 60, when they were divided into: Nx+V receiving vehicle; Nx+L treated with losartan, 50 mg/kg/day; Nx+L+Eple, given losartan and eplerenone, and Nx+L+Ly, given losartan and Ly. Treatments lasted for 90 days. As an add-on to losartan, Ly normalized blood pressure and albuminuria, and prevented CKD progression more effectively than eplerenone. This effect was associated with strong stimulation of PRA and aldosterone. Despite exhibiting higher affinity for the MR than either eplerenone or spironolactone, Ly caused no hyperkalemia. Ly may become a novel asset in the effort to detain the progression of CKD.

Comparison between the effects of hydrochlorothiazide and indapamide on the kidney in hypertensive patients inadequately controlled with losartan

The aim of the study is to compare the effects of hydrochlorothiazide and indapamide on the kidney in patients with hypertension inadequately controlled with losartan. A total of 140 patients who met the criteria and inadequately controlled with losartan 50 mg per day for 2 weeks were randomized in two groups and administered either hydrochlorothiazide 12.5 mg per day (n=70) or indapamide (sustained release) 1.5 mg per day (n=70) in combination with losartan 50 mg per day. Office blood pressure (BP) were collected at baseline and upon each follow-up visit. Creatinine, urine albumin-creatinine ratio (ACR), urine neutrophil gelatinase-associated lipocalin (NGAL) and renal resistive index (RRI) were also collected at baseline and at the 24-week follow-up. None of the baseline characteristics was statistically significantly different between the two groups. After excluding those patients with office BP uncontrolled, 46 patients in the hydrochlorothiazide group (45.7% males, 58.8±10.8 years) and 44 patients in the indapamide group (38.4% males, 61.5±10.9 years) were analysed. There were insignificant changes in creatinine and significant decreases in ACR, NGAL and RRI compared to baseline levels in the two groups. The decrease in ACR (3.8 (0, 28.7) vs 4.2 (0.4, 64.8) mg g^-1, P=0.485) was not significantly different between the two groups, while the decrease in NGAL (16.07±7.07 vs 28.77±7.64 ng ml^-1, P<0.001) and RRI (0.04±0.02 vs 0.07±0.04, P<0.001) was more significant in the indapamide group than in the hydrochlorothiazide group. In conclusion, indapamide is superior to hydrochlorothiazide to improve renal tubular injury and renal haemodynamics in combination with losartan in hypertensive patients with controlled BP.

Focal Segmental Glomerulosclerosis

Focal segmental glomerulosclerosis (FSGS) is a leading cause of kidney disease worldwide. The presumed etiology of primary FSGS is a plasma factor with responsiveness to immunosuppressive therapy and a risk of recurrence after kidney transplant-important disease characteristics. In contrast, adaptive FSGS is associated with excessive nephron workload due to increased body size, reduced nephron capacity, or single glomerular hyperfiltration associated with certain diseases. Additional etiologies are now recognized as drivers of FSGS: high-penetrance genetic FSGS due to mutations in one of nearly 40 genes, virus-associated FSGS, and medication-associated FSGS. Emerging data support the identification of a sixth category: APOL1 risk allele-associated FSGS in individuals with sub-Saharan ancestry. The classification of a particular patient with FSGS relies on integration of findings from clinical history, laboratory testing, kidney biopsy, and in some patients, genetic testing. The kidney biopsy can be helpful, with clues provided by features on light microscopy (e.g, glomerular size, histologic variant of FSGS, microcystic tubular changes, and tubular hypertrophy), immunofluorescence (e.g, to rule out other primary glomerulopathies), and electron microscopy (e.g., extent of podocyte foot process effacement, podocyte microvillous transformation, and tubuloreticular inclusions). A complete assessment of renal histology is important for establishing the parenchymal setting of segmental glomerulosclerosis, distinguishing FSGS associated with one of many other glomerular diseases from the clinical-pathologic syndrome of FSGS. Genetic testing is beneficial in particular clinical settings. Identifying the etiology of FSGS guides selection of therapy and provides prognostic insight. Much progress has been made in our understanding of FSGS, but important outstanding issues remain, including the identity of the plasma factor believed to be responsible for primary FSGS, the value of routine implementation of genetic testing, and the identification of more effective and less toxic therapeutic interventions for FSGS.

Current prescription status of antihypertensive drugs with special reference to the use of diuretics in Japan

The guidelines for the management of hypertension recommend the inclusion of diuretics, especially when three or more antihypertensive drugs are used. The present study investigated the current prescription status of antihypertensive drugs with a particular focus on the use of diuretics in a local district in Japan. Prescriptions, including antihypertensive drugs, were collected from a dispensing pharmacy of the Yahata Pharmacist Association, located in Kitakyushu City, in October 2014. Of the 10 585 prescriptions, calcium channel blockers (CCBs) were prescribed in 73.5%, followed by angiotensin II receptor blockers (ARB, 62.7%), diuretics (16.5%) and β-blockers (13.6%). The average number of drugs used was 1.80. The rates of prescription of diuretics for patients with one, two, three and four drugs were 0.6%, 13.1%, 55.2% and 82.6%, respectively. Diuretics were more frequently prescribed in elderly patients, and the prescription rate of doctors in hospitals was significantly higher than that of general practitioners (19.1% vs. 15.7%, P<0.01). In addition, 40% of patients with thiazide diuretics were prescribed combination tablets of hydrochlorothiazide with ARB, whereas trichlormethiazide (34.9%) and indapamide (19.8%) were used in other patients. Based on these findings, the use of diuretics remains limited, even among patients taking multiple antihypertensive drugs.

An association of losartan-hydrochlorothiazide, but not losartan-furosemide, completely arrests progressive injury in the remnant kidney

We have previously shown that an association of losartan and hydrochlorothiazide, initiated 1 mo after 5/6 nephrectomy (Nx), reversed hypertension and albuminuria and promoted lasting renoprotection. In this new study, we investigated whether equal or even better protection could be obtained by combining losartan and furosemide. Nx was performed in 58 Munich-Wistar rats. One month later, tail-cuff pressure and albuminuria were markedly elevated. At this time, Nx rats were distributed among the following four groups: untreated Nx rats, Nx rats that received losartan, Nx rats that received losartan + hydrochlorothiazide, and Nx rats that received losartan + furosemide. Seven months later, Nx rats exhibited high mortality, severe hypertension, albuminuria, glomerulosclerosis, and interstitial fibrosis. Losartan treatment limited mortality and attenuated the renal and hemodynamic abnormalities associated with Nx. As previously shown, the losartan + hydrochlorothiazide association normalized tail-cuff pressure and albumin, prevented renal injury, and reduced mortality to zero. The losartan + furosemide treatment failed to reduce tail-cuff pressure or albumin to normal and prevented renal injury less efficiently than the losartan and hydrochlorothiazide regimen. The reasons for the differing efficacies of the losartan + furosemide and losartan + hydrochlorothiazide schemes are unclear and may include beneficial nondiuretic actions of thiazides, such as vasorelaxation and antiproliferative activity. These results refute the established concept that thiazides and thiazide-like diuretics are ineffective at advanced chronic kidney disease stages. Rather, they suggest that, in view of their renoprotective action, these compounds may even be preferable to loop diuretics in the management of hypertension in advanced chronic kidney disease.