Thiazide diuretics enhance nocturnal blood pressure fall and reduce proteinuria in immunoglobulin A nephropathy treated with angiotensin II modulators

Current perspective on circadian function of the kidney

Behavior and function of living systems are synchronized by the 24-h rotation of the Earth that guides physiology according to time of day. However, when behavior becomes misaligned from the light-dark cycle, such as in rotating shift work, jet lag, and even unusual eating patterns, adverse health consequences such as cardiovascular or cardiometabolic disease can arise. The discovery of cell-autonomous molecular clocks expanded interest in regulatory systems that control circadian physiology including within the kidney, where function varies along a 24-h cycle. Our understanding of the mechanisms for circadian control of physiology is in the early stages, and so the present review provides an overview of what is known and the many gaps in our current understanding. We include a particular focus on the impact of eating behaviors, especially meal timing. A better understanding of the mechanisms guiding circadian function of the kidney is expected to reveal new insights into causes and consequences of a wide range of disorders involving the kidney, including hypertension, obesity, and chronic kidney disease.

Targeting the Liver with Nucleic Acid Therapeutics for the Treatment of Systemic Diseases of Liver Origin

Systemic diseases of liver origin (SDLO) are complex diseases in multiple organ systems, such as cardiovascular, musculoskeletal, endocrine, renal, respiratory, and sensory organ systems, caused by irregular liver metabolism and production of functional factors. Examples of such diseases discussed in this article include primary hyperoxaluria, familial hypercholesterolemia, acute hepatic porphyria, hereditary transthyretin amyloidosis, hemophilia, atherosclerotic cardiovascular diseases, α-1 antitrypsin deficiency-associated liver disease, and complement-mediated diseases. Nucleic acid therapeutics use nucleic acids and related compounds as therapeutic agents to alter gene expression for therapeutic purposes. The two most promising, fastest-growing classes of nucleic acid therapeutics are antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs). For each listed SDLO disease, this article discusses epidemiology, symptoms, genetic causes, current treatment options, and advantages and disadvantages of nucleic acid therapeutics by either ASO or siRNA drugs approved or under development. Furthermore, challenges and future perspectives on adverse drug reactions and toxicity of ASO and siRNA drugs for the treatment of SDLO diseases are also discussed. In summary, this review article will highlight the clinical advantages of nucleic acid therapeutics in targeting the liver for the treatment of SDLO diseases. SIGNIFICANCE STATEMENT: Systemic diseases of liver origin (SDLO) contain rare and common complex diseases caused by irregular functions of the liver. Nucleic acid therapeutics have shown promising clinical advantages to treat SDLO. This article aims to provide the most updated information on targeting the liver with antisense oligonucleotides and small interfering RNA drugs. The generated knowledge may stimulate further investigations in this growing field of new therapeutic entities for the treatment of SDLO, which currently have no or limited options for treatment.

Therapeutic roles of thiazides and loop diuretics in blood pressure control and renal protection against chronic kidney disease

Fluid overload secondary to loss of functional nephron mass can elevate blood pressure, which is characteristic of hypertension shown in chronic kidney disease (CKD). Therefore, it is logical to use diuretics at appropriate dose to lower blood pressure in patients with CKD and hypertension. Despite the theoretical background on the use of diuretics in CKD, there have been no definitive data on the effectiveness or safety of diuretics as first-line therapy for the management of hypertension in patients with CKD. Results from some clinical trials have demonstrated that diuretics would not lower blood pressure. They could even worsen electrolyte imbalance and kidney function when they are administered in patients with CKD. Major clinical practice guidelines on management of blood pressure or CKD have stated that evidence for benefits of thiazide diuretics is not conclusive yet in patients with advanced CKD, although loop diuretics are often effective for volume control at lower glomerular filtration rate. Recently, evidence for diuretics as effective blood pressure lowering agents in patients with advanced CKD is increasing. Renoprotective effect of thiazide or loop diuretics might represent a consequence of their influence on blood pressure or their ability to potentiate the effect of renin-angiotensin system blockade by making intraglomerular pressure more renin-angiotensin system-dependent, although their direct benefit on renal function remains controversial. This review summarizes recent data on the possible role of diuretics in lowering blood pressure, slowing the progression of kidney disease, and reducing cardiovascular risk in CKD patients.

Spectroscopic studies, quantum chemical investigations, and in silico and in vitro scrutiny of the diuretic drug trichlormethiazide adsorbed on AuNPs

Experimental and theoretical study was employed to study the adsorption of the diuretic drug, trichlormethiazide (TCM) molecule on AuNPs (TCMA). The stereoelectronic properties of the molecular structure of most stable conformers of TCM and TCMA were studied using DFT/B3LYP-6-311++G (d, p) together with LANL2DZ methodology. The Fourier transform Raman and Infrared spectra of TCM were recorded and analyzed. Quantum chemical calculations of TCM and TCMA molecules were used to evaluate the stability of the molecule, hyper-conjugative interactions, electron delocalization, and binding interactions. The calculated and experimentally observed vibrational frequencies of the molecule were assigned and compared. The shifting and intensity enhancement of the CCl₂ band manifests the back-donation and conjugation effect, which are the result of the presence of nitrogen atom adjoining the dichloromethyl groups and the oxygen in the sulfur dioxide group attached among the amino group and the chlorophenyl ring, respectively, which enhances bioactivity. Anticancer activity was examined based on molecular docking analysis, and it was identified that TCM and TCMA molecules act as good inhibitors against lung cancer. SERS analysis and MTT assay confirmed the molecular docking analysis results.

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.

Enumerating the role of properdin in the pathogenesis of IgA nephropathy and its possible therapies

BACKGROUND

IgA nephropathy (IgAN) has become the most prevalent form of glomerulonephritis affecting almost 1.3% of the total population worldwide. It is an autoimmune disorder where the host autoantibody forms an immune complex with the defective galactose-deficient IgA1 and gets deposited at the mesangium and endocapillary region of glomeruli. IgA has the capability to activate alternative and lectin complement cascades which even aggravates the condition. Properdin is directly associated with IgAN by activating and stabilising the alternative complement pathway at the mesangium, thereby causing progressive renal damage.

OBJECTIVE

The present review mainly focuses on correlating the influence of properdin in activating the complement cascade at glomeruli which is the major cause of disease exacerbation. Secondly, we have described the probable therapies and new targets that are under trials to check their efficacy in IgAN.

METHODS

An in-depth research was carried out from different peer-reviewed articles till December 2020 from several renowned databases like PubMed, Frontier, and MEDLINE, and the information was analysed and written in a simplified manner.

RESULTS

Co-deposition of properdin is observed along with IgA and C3 in 75%-100% of the patients. It is not yet fully understood whether properdin inhibition can attenuate IgAN, as many conflicting reports have revealed worsening of IgAN after impeding properdin.

CONCLUSION

With no specific cure still available, the treatment strategies are of great concern to find a better target to restrict the disease progression. More research and clinical trials are required to find out a prominent target to combat IgAN.

Circadian rhythms and the kidney

Numerous physiological functions exhibit substantial circadian oscillations. In the kidneys, renal plasma flow, the glomerular filtration rate and tubular reabsorption and/or secretion processes have been shown to peak during the active phase and decline during the inactive phase. These functional rhythms are driven, at least in part, by a self-sustaining cellular mechanism termed the circadian clock. The circadian clock controls different cellular functions, including transcription, translation and protein post-translational modifications (such as phosphorylation, acetylation and ubiquitylation) and degradation. Disruption of the circadian clock in animal models results in the loss of blood pressure control and substantial changes in the circadian pattern of water and electrolyte excretion in the urine. Kidney-specific suppression of the circadian clock in animals implicates both the intrinsic renal and the extrarenal circadian clocks in these pathologies. Alterations in the circadian rhythm of renal functions are associated with the development of hypertension, chronic kidney disease, renal fibrosis and kidney stones. Furthermore, renal circadian clocks might interfere with the pharmacokinetics and/or pharmacodynamics of various drugs and are therefore an important consideration in the treatment of some renal diseases or disorders.

Why, when and how should immunosuppressive therapy considered in patients with immunoglobulin A nephropathy?

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Lifelong mesangial deposition of IgA1 complexes subsist inflammation and nephron loss, but the complex pathogenesis in detail remains unclear. In regard to the heterogeneous course, classical immunosuppressive and specific therapeutic regimens adapted to the loss of renal function will here be discussed in addition to the essential common renal supportive therapy. Renal supportive therapy alleviates secondary, surrogate effects or sequelae on renal function and proteinuria of high intraglomerular pressure and subsequent nephrosclerosis by inhibition of the renin angiotensin system (RAASB). In patients with physiological (ΔGFR < 1·5 ml/min/year) or mild (ΔGFR 1·5-5 ml/min/year) decrease of renal function and proteinuric forms (> 1 g/day after RAASB), corticosteroids have shown a reduction of proteinuria and might protect further loss of renal function. In patients with progressive loss of renal function (ΔGFR > 3 ml/min within 3 months) or a rapidly progressive course with or without crescents in renal biopsy, cyclophosphamide with high-dose corticosteroids as induction therapy and azathioprine maintenance has proved effective in one randomized controlled study of a homogeneous cohort in loss of renal function (ΔGFR). Mycophenolic acid provided further maintenance in non-randomized trials. Differentiated, precise, larger, randomized, placebo-controlled studies focused on the loss of renal function in the heterogeneous forms of IgAN are still lacking. Prospectively, fewer toxic agents will be necessary in the treatment of IgAN.

Addition of hydrochlorothiazide to angiotensin receptor blocker therapy can achieve a lower sodium balance with no acceleration of intrarenal renin angiotensin system in patients with chronic kidney disease

Objective:

Angiotensin receptor blockers (ARBs) produce a lower sodium (Na) balance, and the natriuretic effect is enhanced under Na deprivation, despite falls in blood pressure (BP) and glomerular filtration rate (GFR).

Methods:

The effect of additional hydrochlorothiazide (HCTZ; 12.5 mg/day) to ARB treatment (valsartan; 80 mg/day) on glomerulotubular Na balance was evaluated in 23 patients with chronic kidney disease.

Results:

Add-on HCTZ decreased GFR, tubular Na load, and tubular Na reabsorption (t_Na), although 24-hour urinary Na excretion (U_NaV) remained constant. Daily urinary angiotensinogen excretion (U_AGTV, 152±10→82±17 μg/g Cre) reduced (p=0.02). Changes in tubular Na load (r²=0.26) and t_Na (r²=0.25) correlated with baseline 24-hour U_AGTV. Changes in filtered Na load correlated with changes in nighttime systolic BP (r²=0.17), but not with changes in daytime systolic BP. The change in the t_Na to filtered Na load ratio was influenced by the change in daytime U_NaV (β=−0.67, F=16.8), rather than the change in nighttime U_NaV.

Conclusions:

Lower Na balance was produced by add-on HCTZ to ARB treatment without an increase of intra-renal renin-angiotensin system activity, leading to restoration of nocturnal hypertension. A further study is needed to demonstrate that the reduction of U_AGTV by additional diuretics to ARBs prevents the progression of nephropathy or cardiovascular events.

A prospective randomized trial examining health care utilization in individuals using multiple smartphone-enabled biosensors

Background. Mobile health and digital medicine technologies are becoming increasingly used by individuals with common, chronic diseases to monitor their health. Numerous devices, sensors, and apps are available to patients and consumers-some of which have been shown to lead to improved health management and health outcomes. However, no randomized controlled trials have been conducted which examine health care costs, and most have failed to provide study participants with a truly comprehensive monitoring system. Methods. We conducted a prospective randomized controlled trial of adults who had submitted a 2012 health insurance claim associated with hypertension, diabetes, and/or cardiac arrhythmia. The intervention involved receipt of one or more mobile devices that corresponded to their condition(s) (hypertension: Withings Blood Pressure Monitor; diabetes: Sanofi iBGStar Blood Glucose Meter; arrhythmia: AliveCor Mobile ECG) and an iPhone with linked tracking applications for a period of 6 months; the control group received a standard disease management program. Moreover, intervention study participants received access to an online health management system which provided participants detailed device tracking information over the course of the study. This was a monitoring system designed by leveraging collaborations with device manufacturers, a connected health leader, health care provider, and employee wellness program-making it both unique and inclusive. We hypothesized that health resource utilization with respect to health insurance claims may be influenced by the monitoring intervention. We also examined health-self management. Results & Conclusions. There was little evidence of differences in health care costs or utilization as a result of the intervention. Furthermore, we found evidence that the control and intervention groups were equivalent with respect to most health care utilization outcomes. This result suggests there are not large short-term increases or decreases in health care costs or utilization associated with monitoring chronic health conditions using mobile health or digital medicine technologies. Among secondary outcomes there was some evidence of improvement in health self-management which was characterized by a decrease in the propensity to view health status as due to chance factors in the intervention group.

Effect of N- and T-type calcium channel blocker on proteinuria, blood pressure and kidney function in hypertensive patients: a meta-analysis

The combination of a calcium channel blocker (CCB) and a blocker of the renin-angiotensin-aldosterone system (RAAS) is recommended in clinical practice guidelines. L/N- and L/T-type CCBs might provide an additional effect on lowering proteinuria. Therefore, we conducted a meta-analysis to assess the efficacy of L/N- and L/T-type CCBs in hypertensive patients with proteinuria. We searched MEDLINE, Scopus, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov for single-arm studies and randomized controlled trials (RCTs) that examined the effect of L/N- and L/T-type CCBs as add-on therapy compared with standard antihypertensive regimen for proteinuria on hemodynamic and kidney-related parameters in hypertensive patients with proteinuria. Random-effect model meta-analyses were used to compute changes in the outcomes of interest. We identified 17 RCTs, representing 1905 patients. By meta-analysis, L/N- and L/T-type CCB add-on therapy did not yield significant changes in systolic and diastolic blood pressure compared with standard treatment, but there was a significant lowering of the pulse rate. However, L/N- and L/T-type CCBs resulted in a significant standardized net decrease in albuminuria and proteinuria (-1.01; 95% confidence interval (CI), -1.78 to -0.23; P=0.01), and a standardized net improvement in the estimated glomerular filtration rate and serum creatinine (0.23; 95% CI, 0.11 to 0.35, P<0.001; and -0.25; 95% CI, -0.46 to -0.03; P=0.02, respectively). Despite no additional lowering effect on blood pressure, L/N- and L/T-type CCBs combined with a blocker of the RAAS provided a decrease in proteinuria and improvement in kidney function. Further studies are required to establish the long-term kidney benefits of this combination therapy.

Influence of angiotensin II receptor blocker combination tablet prescription on drug number and cost

OBJECTIVES

Combination therapy using an angiotensin II receptor blocker is expected to promote medication adherence and alleviate economic burden among patients by reducing the number of drugs taken, and thereby to lower associated medical costs. In the present retrospective study, we conducted a survey on the use of angiotensin II receptor blocker-containing combination tablets as anti-hypertensive drugs, in particular angiotensin II receptor blocker/diuretic and angiotensin II receptor blocker/calcium channel blocker combinations, in order to investigate the number of prescribed drugs and drug cost.

METHODS

We performed a retrospective study of patients who visited the outpatient clinic of GifuMunicipalHospital and received anti-hypertensive agents between June 2006 and December 2011.

RESULTS

No reductions in the number of prescribed drugs or drug cost were seen following a change in prescription to an angiotensin II receptor blocker/diuretic. Patients receiving an angiotensin II receptor blocker/calcium channel blocker had a significant reduction in the number of prescribed drugs and a slight decrease in drug cost.

CONCLUSION

In this study, a reduction in the number of prescribed drugs and a decrease in economic burden were not observed after prescription of angiotensin II receptor blocker-containing combination tablets. In order to assess the usefulness of angiotensin II receptor blocker combination tablets, further studies are necessary to investigate their hypotensive effects, safety profile, and other factors.

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

It is unknown whether the use of diuretics is optimal over other antihypertensive agents in patients with chronic kidney disease (CKD) whose blood pressure remains uncontrolled despite treatment with renin-angiotensin system (RAS) inhibitors. In this study, we assessed the additive effects of hydrochlorothiazide (HCTZ) on reducing proteinuria in CKD patients under treatment with losartan (LS). We conducted a multicenter, open-labeled, randomized trial. One hundred and two CKD patients with hypertension and overt proteinuria were recruited from nine centers and randomly assigned to receive either LS (50 mg, n=51) or a combination of LS (50 mg per day) and HCTZ (12.5 mg per day) (LS/HCTZ, n=51). The primary outcome was a decrease in the urinary protein-to-creatinine ratio (UPCR). The target blood pressure was <130/80 mm Hg, and antihypertensive agents (other than RAS inhibitors and diuretics) were added if the target was not attained. Baseline characteristics of the two groups were similar. After 12 months of treatment, decreases in the UPCR were significantly greater in the LS/HCTZ group than in the LS group. There were no significant differences in blood pressure or the estimated glomerular filtration rate between the two groups. LS/HCTZ led to a greater reduction in proteinuria than treatment with LS, even though blood pressure in the LS group was similar to that in the LS/HCTZ group following the administration of additive antihypertensive agents throughout the observation period. This finding suggests that LS/HCTZ exerts renoprotective effects through a mechanism independent of blood pressure reduction.

Comparison of the antialbuminuric effects of benidipine and hydrochlorothiazide in Renin-Angiotensin System (RAS) inhibitor-treated hypertensive patients with albuminuria: the COSMO-CKD (COmbination Strategy on Renal Function of Benidipine or Diuretics TreatMent with RAS inhibitOrs in a Chronic Kidney Disease Hypertensive Population) study

OBJECTIVE

This study evaluated the non-inferiority of renoprotection afforded by benidipine versus hydrochlorothiazide in hypertensive patients with chronic kidney disease (CKD).

METHODS

In this prospective, multicenter, open-labeled, randomized trial, the antialbuminuric effects of benidipine and hydrochlorothiazide were examined in renin-angiotensin system (RAS) inhibitor-treated patients with blood pressure (BP) readings of ≥ 130/80 mmHg and ≤ 180/110 mmHg, a urinary albumin to creatinine ratio (UACR) of ≥ 300 mg/g, and an estimated glomerular filtration rate (eGFR) of ≥ 30 ml/min/1.73m(2). Patients received benidipine (n = 176, final dose: 4.8 mg/day) or hydrochlorothiazide (n = 170, 8.2 mg/day) for 12 months.

RESULTS

Benidipine and hydrochlorothiazide exerted similar BP- and eGFR-decreasing actions. The UACR values for benidipine and hydrochlorothiazide were 930.8 (95% confidence interval: 826.1, 1048.7) and 883.1 (781.7, 997.7) mg/g at baseline, respectively. These values were reduced to 790.0 (668.1, 934.2) and 448.5 (372.9, 539.4) mg/g at last observation carried forward (LOCF) visits. The non-inferiority of benidipine versus hydrochlorothiazide was not demonstrated (benidipine/hydrochlorothiazide ratio of LOCF value adjusted for baseline: 1.67 (1.40, 1.99)).

CONCLUSIONS

The present study failed to demonstrate the non-inferiority of the antialbuminuric effect of benidipine relative to that of hydrochlorothiazide in RAS inhibitor-treated hypertensive patients with macroalbuminuria.

Duration until nighttime blood pressure fall indicates excess sodium retention

Impaired renal sodium excretion causes sodium retention, which prevents the nocturnal dip in blood pressure (BP); thus, high BP persists until excess sodium is excreted. The authors defined "dipping time" (DT) as the duration until the nocturnal BP falls below 90% of the daytime average. Diuretic (e.g., hydrochlorothiazide [HCTZ]) and angiotensin receptor blocker (ARB) are able to eliminate sodium retention and restore the non-dipper BP rhythm. Reanalysis of two previous studies demonstrate that HCTZ and ARB shortened the DT. Shortening DT correlated directly with the increase in daytime urinary sodium excretion (Study 2). DT can be used as a preliminary indicator of sodium retention.

Proximal tubular angiotensinogen in renal biopsy suggests nondipper BP rhythm accompanied by enhanced tubular sodium reabsorption

OBJECTIVES

The renal capacity for sodium excretion is impaired by a reduction in the glomerular ultrafiltration coefficient and by enhancement of the fractional tubular sodium reabsorption (FRNa), leading to a nondipper circadian blood pressure (BP) rhythm. Angiotensin II in the systemic circulation can be easily filtered across the glomerular capillary walls and stimulates renal proximal tubular angiotensinogen (PT-AGT) production, leading to the activation of intrarenal angiotensin II, which is known to augment the FRNa in animal models.

METHODS

We performed an immunohistochemical investigation to determine the contribution of PT-AGT to enhancement of FRNa and the nondipper circadian BP rhythm in 40 consecutive patients with primary IgA nephropathy (IgAN).

RESULTS

Immunostaining for PT-AGT was increased in the IgAN patients compared with control individuals (P = 0.04), and correlated directly with the FRNa (r = 0.39, P = 0.01) and the night/day ratio of BP (r = 0.38, P = 0.02), but not creatinine clearance (r = -0.008, P = 0.9). The night/day ratio of BP was determined by both creatinine clearance (r = -0.36, P = 0.03) and FRNa (r = 0.47, P = 0.006).

CONCLUSION

Tubular sodium reabsorption is stimulated by intrarenal angiotensin II, as indicated by PT-AGT, and contributes to the genesis of the nondipper BP rhythm. Further studies are needed to evaluate whether or not treatment to prevent sodium retention is useful for patients who exhibit increased PT-AGT in renal biopsies.

Low dose of hydrochlorothiazide, in combination with angiotensin receptor blocker, reduces blood pressure effectively without adverse effect on glucose and lipid profiles

Previous studies have shown highly effective lowering of blood pressure with thiazide diuretics in combination with angiotensin receptor blockers. However, thiazide diuretics may cause the development of diabetes and abnormal lipid metabolism. Little is known as to whether dysmetabolic potential of thiazide diuretics could be neutralized when adding angiotensin receptor blockers. This study consisted of 26 patients with essential hypertension. Patients were randomized to 24 weeks of treatment with either candesartan, 12 mg monotherapy (n = 13, group A), or hydrochlorothiazide (HCTZ), 6.25 mg in combination with candesartan, 8 mg (n = 13, group B). Before and after treatment, we assessed glucose and lipid profiles including adiponectin, resistin, and active glucagon-like peptide-1 (GLP-1) levels. At baseline, there were no differences in age, body mass index, systolic blood pressure (SBP), and diastolic blood pressure (DBP), as well as plasma levels of hemoglobin A1c, insulin, low-density lipoprotein cholesterol, triglycerides, adiponectin, resistin, and active GLP-1 between the two groups. There were significant reductions in SBP (from 152 ± 10 mmHg at baseline to 134 ± 12 mmHg after treatment) and DBP (from 84 ± 5 mmHg at baseline to 71 ± 8 mmHg after treatment) in group A. There were also significant reductions in SBP (from 148 ± 10 at baseline to 128 ± 7 mmHg after treatment) and DBP (from 90 ± 9 at baseline to 74 ± 12 mmHg after treatment) in group B. There were no differences in reduction of SBP or DBP after 24 weeks of treatment between the two groups. There were no changes of the glucose and lipid profiles, including adiponectin, resistin, insulin, and active GLP-1 levels after 24 weeks of treatment in both groups. A low dose of HCTZ in combination with candesartan reduces blood pressure effectively without adverse effects on the glucose and lipid profiles. Therefore, the combination of thiazide diuretics and angiotensin receptor blockers could assist patients in achieving long-term control of blood pressure with good tolerability.

Mechanism underlying the efficacy of combination therapy with losartan and hydrochlorothiazide in rats with salt-sensitive hypertension

Although thiazide diuretics are commonly used to supplement angiotensin receptor blockers for treatment of hypertension, the mechanism underlying the therapeutic effects of this drug combination remains unclear. We investigated the antihypertensive and cardioprotective effects of combination therapy with losartan (LOS) and hydrochlorothiazide (HCTZ), in comparison with those of either drug alone, in Dahl salt-sensitive hypertensive rats. Rats fed a high-salt diet from 6 weeks of age were treated with LOS, HCTZ, both drugs (COMB) and vehicle from 6 to 11 weeks. The salt-induced increase in systolic blood pressure was attenuated moderately by LOS and to a greater extent by HCTZ and COMB. Left ventricular (LV) hypertrophy and fibrosis, diastolic dysfunction, as well as angiotensin-converting enzyme and angiotensin II type 1A (AT(1A)) receptor gene expression were attenuated similarly by LOS and HCTZ and more so by COMB. LOS downregulated expression of the AT(1A) receptor gene, without affecting that of the AT(2) receptor gene, in the aorta. In contrast, neither HCTZ nor COMB affected aortic expression of the AT(1A) receptor gene, but both markedly upregulated that of the AT(2) receptor gene. The salt-induced decrease in the plasma concentration of nitric oxide metabolites was attenuated substantially by LOS and abolished by both HCTZ and COMB. In conclusion, the combination of LOS and HCTZ attenuated hypertension, as well as LV remodeling and diastolic dysfunction, more effectively than did LOS or HCTZ alone in rats with salt-sensitive hypertension. Modulation of the cardiac and vascular renin-angiotensin system may have contributed to these beneficial effects of the drug combination.

Urinary albumin excretion during angiotensin II receptor blockade: comparison of combination treatment with a diuretic or a calcium-channel blocker

BACKGROUND

We aimed to test the hypothesis that the angiotensin II receptor blocker (ARB)/diuretic combination decreases the urinary albumin/creatinine ratio (UACR) to a greater extent than treatment with the ARB/calcium-channel blocker (CCB) combination through a mechanism related to a greater reduction of sleep blood pressure (BP).

METHODS

We conducted a prospective, randomized, open-label, blinded end-point trial in hypertensive patients. Patients received olmesartan monotherapy for 12 weeks, followed by an additional use of hydrochlorothiazide (HCTZ) (n = 104) or azelnidipine (n = 103) for 24 weeks after randomization. The measurements of central and ambulatory BP, and laboratory tests were performed at baseline and the end of the study.

RESULTS

The adjusted percent reduction in UACR in the olmesartan/HCTZ group was significantly greater than that in the olmesartan/azelnidipine group (-43.2 vs. -24.0%, P = 0.0014), although the olmesartan/azelnidipine group showed greater decreases in central systolic BP (SBP; P = 0.04), oxidative stress (urinary 8-isoprostane; P = 0.02), inflammation (high-sensitivity C-reactive protein; P = 0.04), and insulin resistance (the homeostasis model assessment insulin resistance index (HOMA(IR)); P < 0.001) than the olmesartan/HCTZ group. In multivariate regression analyses, the significant determinants of change in UACR in the olmesartan/HCTZ group were changes in sleep SBP (P < 0.001), central SBP (P = 0.01), estimated glomerular filtration rate (eGFR) (P = 0.02), and HOMA(IR) (P = 0.03), and those in the olmesartan/azelnidipine group were changes in central SBP (P = 0.001) and urinary 8-isoprostane (P = 0.02).

CONCLUSIONS

These data showed that the ARB/diuretic combination decreased UACR significantly more than the ARB/CCB combination, and this decrease in UACR was associated with a greater magnitude reduction in sleep SBP.

Efficacy of eplerenone added to renin-angiotensin blockade in elderly hypertensive patients: the Jichi-Eplerenone Treatment (JET) study

INTRODUCTION

We assessed the additional effects of eplerenone to angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs) on 24-h blood pressure (BP) level, fibrinolytic activity, and cardiovascular protection in elderly (>60 years) hypertensive patients.

MATERIALS AND METHODS

In total, 20 patients (mean age 74 years, 25% men), whose BP was uncontrolled despite the use of anti-hypertensive drugs including ACEIs or ARBs (average 2.4 drugs), received eplerenone once daily (mean 37.5 mg) for 24 weeks.

RESULTS

Eplerenone treatment significantly reduced mean 24-h systolic/diastolic BP levels (143/80 mmHg to 132/74 mmHg, both p < 0.002). The reduction of 24-h systolic BP levels, especially night-time BP, was significantly associated with the reduction of atrial natriuretic peptide and brain natriuretic peptide levels (all p < 0.05). Furthermore, after eplerenone treatment, the mean plasminogen activator inhibitor-1 antigen level was significantly reduced (35 ng/ml to 25 ng/ml, p < 0.05), and the median level of plasma procollagen type III aminoterminal peptide and the urinary albumin excretion rate were also significantly reduced (0.8 U/ml to 0.6 U/ml, p < 0.003 and 53 mg/g·Cr to 23 mg/g·Cr, p < 0.05, respectively). During the intervention, eplerenone treatment was well tolerated with no reports of hyperkalaemia or hypotension.

CONCLUSIONS

Addition of eplerenone to ACEIs or ARBs in elderly hypertensive patients offers significant benefits in terms of 24-h BP levels, fibrinolysis, and cardiovascular protection.

Ambulatory pulse pressure, decreased nocturnal blood pressure reduction and progression of nephropathy in type 2 diabetic patients

AIMS/HYPOTHESIS

We followed type 2 diabetic patients over a long period to evaluate the predictive value of ambulatory pulse pressure (PP) and decreased nocturnal BP reduction (non-dipping) for nephropathy progression.

METHODS

Type 2 diabetic patients (n = 112) were followed for an average of 9.5 (range 0.5-14.5) years. At baseline, all patients underwent 24 h ambulatory BP measurement. Urinary albumin excretion rate was evaluated by three urinary albumin:creatinine ratio measurements at baseline and follow-up.

RESULTS

At baseline, patients who subsequently progressed to a more advanced nephropathy stage (n = 35) had reduced diastolic night/day BP variation and higher 24 h systolic BP and PP values; they also had more advanced nephropathy and were more likely to smoke than those with no progression of nephropathy (n = 77). In a Cox regression analysis, independent predictors of nephropathy progression were 24 h PP (p < 0.01), diastolic night:day BP ratio (p = 0.02) and smoking (p = 0.02). The adjusted hazards ratio (95% CI) for each mmHg increment in 24 h PP was 1.04 (1.01-1.07), whereas the adjusted hazards ratio (95% CI) for each 1% increase in diastolic night:day BP ratio was 1.06 (1.01-1.11). Only one of 33 patients (3.0%) with both a diastolic night:day BP ratio and a 24 h PP below the median progressed, whereas 17 of 32 patients (53.1%) with both a diastolic night:day BP ratio and a 24 h PP equal to or above the median progressed to a more advanced nephropathy stage (p < 0.001).

CONCLUSIONS/INTERPRETATION

Ambulatory PP, impaired nocturnal BP decline and smoking are strong, independent predictors of nephropathy progression in type 2 diabetic patients.

Effects of high sodium intake and diuretics on the circadian rhythm of blood pressure in type 2 diabetic patients treated with an angiotensin II receptor blocker

BACKGROUND

The inhibition of the renin-angiotensin system in the diabetic condition was reported to enhance the sodium sensitivity of blood pressure. In patients with sodium-sensitive hypertension, high sodium intake reduces the nocturnal fall in blood pressure. Therefore, we examined the effects of the amount of sodium intake or diuretics in patients with diabetes treated with an angiotensin receptor blocker.

METHODS

We recruited 32 Japanese type 2 diabetic patients with base line blood pressure > or =130/80 mmHg and treated with valsartan (80 mg daily). At baseline, 24-h ambulatory blood pressure and 24-h urinary excretion of sodium were measured. The patients were then randomly assigned to take either combination therapy with 50 mg of losartan plus 12.5 mg of hydrochlorothiazide or monotherapy with 160 mg of valsartan for 24 weeks.

RESULTS

At baseline, 22 of 32 (69%) patients were classified as non-dippers, and the night/day ratio of mean arterial pressure was significantly correlated with 24-h urinary sodium excretion. The combination therapy resulted in a significantly higher fall than the monotherapy in 24-h mean, daytime, night-time and morning blood pressures. The night/day ratio of mean arterial pressure was significantly reduced from the baseline at the end of the study in the combination therapy group, but not in the monotherapy group. In non-dipper patients, the diminished nocturnal fall in blood pressure was restored by the combination therapy.

CONCLUSIONS

Excessive intake of salt causes non-dipping and diuretics restored nocturnal BP fall in type 2 diabetic patients treated with angiotensin 2 receptor blockers.

Disparate estimates of hypertension control from ambulatory and clinic blood pressure measurements in hypertensive kidney disease

Ambulatory blood pressure (ABP) monitoring provides unique information about day-night patterns of blood pressure (BP). The objectives of this article were to describe ABP patterns in African Americans with hypertensive kidney disease, to examine the joint distribution of clinic BP and ABP, and to determine associations of hypertensive target organ damage with clinic BP and ABP. This study is a cross-sectional analysis of baseline data from the African American Study of Kidney Disease Cohort Study. Masked hypertension was defined by elevated daytime (>or= 135/85 mm Hg) or elevated nighttime (>or= 120/70 mm Hg) ABP in those with controlled clinic BP (<140/90 mm Hg); nondipping was defined by a Collapse

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MESH Headings

• Adolescent
• Adult
• Black or African American/ethnology
• Aged
• Ambulatory Care Facilities
• Blood Pressure/physiology
• Blood Pressure Monitoring, Ambulatory
• Circadian Rhythm/physiology
• Cohort Studies
• Cross-Sectional Studies
• Female
• Humans
• Hypertension, Renal/ethnology
• Hypertension, Renal/physiopathology
• Kidney/physiopathology
• Kidney Diseases/ethnology
• Kidney Diseases/physiopathology
• Male
• Middle Aged
• Prevalence
• Reproducibility of Results
• Severity of Illness Index
• Young Adult

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Grants

• P20-RR11145 NCRR NIH HHS
• M01 RR00827 NCRR NIH HHS
• 5M01 RR-00071 NCRR NIH HHS
• 2P20 RR11104 NCRR NIH HHS

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Affiliation(s)

Velvie Pogue Division of Nephrology, Department of Medicine, Columbia University Medical Center, Harlem Hospital Center, New York, NY 10037, USA.
Mahboob Rahman
Michael Lipkowitz
Robert Toto
Edgar Miller
Marquetta Faulkner
Stephen Rostand
Leena Hiremath
Mohammed Sika
Cynthia Kendrick
Bo Hu
Tom Greene
Lawrence Appel
Robert A Phillips

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Angiotensin II type 1 receptor blocker, olmesartan, restores nocturnal blood pressure decline by enhancing daytime natriuresis

OBJECTIVE

We have shown that as renal function deteriorated, night-time fall in both blood pressure and urinary sodium excretion were diminished. We have also reported that sodium intake restriction and diuretics both normalized circadian blood pressure rhythm from nondipper to dipper patterns. In this study, we investigated whether an angiotensin II receptor blocker, olmesartan, could restore night-time blood pressure fall.

METHODS

Twenty patients with chronic kidney disease (13 men, seven women; mean age 44.8 +/- 18.1 years; BMI 22.9 +/- 3.5 kg/m2) were studied. At baseline and 8 weeks after the treatment with olmesartan medoxomil (10-40 mg/day), 24-h blood pressure monitoring and urinary sampling for both daytime (0600-2100 h) and night-time (2100-0600 h) were repeated to compare the circadian rhythms of blood pressure and urinary sodium excretion.

RESULTS

The 24-h mean arterial pressure was lowered by olmesartan, while urinary sodium excretion remained unchanged. On the other hand, daytime urinary sodium excretion was increased from 4.8 +/- 2.2 to 5.7 +/- 2.1 mmol/h, while night-time urinary sodium excretion tended to be reduced from 3.9 +/- 1.7 to 3.4 +/- 1.6 mmol/h. Night/day ratios of mean arterial pressure (0.98 +/- 0.1 to 0.91 +/- 0.08; P = 0.01) and urinary sodium excretion (0.93 +/- 0.5 to 0.68 +/- 0.4; P = 0.0006) were both decreased. Olmesartan enhanced night-time falls more in mean arterial pressure (r = 0.77; r2 = 0.59; P < 0.0001) and urinary sodium excretion (r = 0.59; r2 = 0.34; P = 0.007), especially in patients whose baseline night-time falls were more diminished.

CONCLUSIONS

These findings demonstrated that olmesartan could restore night-time blood pressure fall, as seen with diuretics and sodium restriction, possibly by enhancing daytime sodium excretion. Since nocturnal blood pressure is a strong predictor of cardiovascular events, olmesartan could relieve cardiorenal load through normalization of circadian blood pressure rhythm besides having powerful ability to block the renin-angiotensin system.

Effect of renin-angiotensin-aldosterone system triple blockade on non-diabetic renal disease: addition of an aldosterone blocker, spironolactone, to combination treatment with an angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker

Although dual blockade of the renin-angiotensin-aldosterone system (RAAS) with the combination of an angiotensin-converting enzyme inhibitor (ACE-I) and angiotensin II receptor blocker (ARB) is generally well-established as a treatment for nephropathy, this treatment is not fully effective in some patients. Based on the recent evidence implicating aldosterone in renal disease progression, this study was conducted to examine the efficacy of blockade with three different mechanisms by adding an aldosterone blocker in patients who do not respond adequately to the dual blockade. A 1-year randomized, open-label, multicenter, prospective controlled study was conducted, in which 32 non-diabetic nephropathy patients with proteinuria exceeding 0.5 g/day were enrolled after more than 12 weeks of ACE-I (5 mg enalapril) and ARB (50 mg losartan) combination treatment. These patients were allocated into two groups of 16 patients each: a triple blockade group in which 25 mg of spironolactone daily was added to the ACE-I and ARB combination treatment, and a control group in which 1 mg of trichlormethiazide or 20 mg of furosemide was added to the combination treatment instead of spironolactone depending upon the creatinine level. After 1 year of treatment, the urinary protein level decreased by 58% (p<0.05) with the triple blockade but was unchanged in the controls. Furthermore, urinary type IV collagen level decreased by 40% (p<0.05) with the triple blockade but was unchanged in the controls. The decreases in urinary protein and urinary type IV collagen were not accompanied by a decrease in blood pressure. Mean serum creatinine, potassium and blood pressure did not change significantly by either treatment. In conclusion, triple blockade of the RAAS was effective for the treatment of proteinuria in patients with non-diabetic nephropathy whose increased urinary protein had not responded sufficiently to a dual blockade.

Nocturnal blood pressure elevation predicts progression of albuminuria in elderly people with type 2 diabetes

Ambulatory 24-hour pulse pressure predicts progression of albuminuria in persons with diabetes mellitus. The authors assessed whether nocturnal blood pressure (BP) patterns added predictive information and examined the multivariate-adjusted association of nocturnal BP patterns with progression of urine albumin excretion during follow-up in a multiethnic cohort of older people (n=957) with type 2 diabetes mellitus who were free of macroalbuminuria. Albuminuria was assessed by spot urine measurement of albumin-to-creatinine ratio at baseline and annually for 3 years. Participants were categorized according to their sleep/wake systolic BP ratio as dippers (ratio </=0.9; n=295), nondippers (flat nocturnal pattern, ratio >0.9 to 1; n=475), and nocturnal BP risers (ratio >1; n=187). The proportion exhibiting progression of albuminuria in dippers, nondippers, and risers was 17.6%, 22.9%, and 27.3%, respectively (P for linear trend = .01). A nocturnal BP rise was independently associated with progression of albuminuria (hazard ratio, 1.68; 95% confidence interval [CI], 1.09-2.60; P=.02), whereas office pulse pressure was not. When ambulatory 24-hour pulse pressure was added to the model, the nocturnal BP rise remained an independent predictor of progression of albuminuria (hazard ratio, 1.58; 95% CI, 1.02-2.45; P=.04). Nocturnal nondipping (without BP increase) was not an independent predictor. In conclusion, nocturnal BP rise on ambulatory monitoring is superior to office BP to predict worsening of albuminuria in elderly individuals with type 2 diabetes and adds to the information provided by 24-hour pulse pressure.

Losartan-hydrochlorothiazide association promotes lasting blood pressure normalization and completely arrests long-term renal injury in the 5/6 ablation model

The possible long-term renoprotective effects of treatment with thiazides, either as monotherapy or associated with renin-angiotensin suppressors, have not been assessed. We investigated the effect of hydrochlorothiazide (H), alone or combined with losartan (L), in the 5/6 renal ablation model (Nx). Adult male Munich-Wistar rats underwent Nx, remaining untreated for 1 mo. At this time, functional and morphological studies were performed in 21 rats (group Nx(pre)). The remaining rats were distributed among groups: Nx, no treatment; Nx+L, receiving L, 50 mg kg(-1) day(-1) in the drinking water; Nx+H, receiving H, 6 mg kg(-1) day(-1) in drinking water; and Nx+L+H, receiving both L and H as described. At 30 days of treatment, systemic and glomerular pressures were markedly elevated in group Nx. Both H and L attenuated hypertension, whereas combined L+H treatment completely normalized both pressures. Eight months after Nx, mortality approached 70% in untreated rats, whereas severe albuminuria, hypertension, glomerulosclerosis, and interstitial expansion were observed. H and L attenuated, but did not prevent, mortality, hypertension, and renal injury. Combined L+H treatment completely prevented mortality, normalized albuminuria and blood pressure, and arrested renal injury at levels found 1 mo after ablation, despite the unusually long period of observation. Combined L+H treatment may represent an effective therapeutic alternative to prevent progression of chronic nephropathies.

Pathophysiology of Antihypertensive Therapy with Diuretics

Recent progress in antihypertensive therapy has widened the selection of drugs, and large clinical trials have attracted attention to newer classes of antihypertensives. Consequently, the use of diuretics as antihypertensive agents has been relatively reduced, particularly since the newer drugs are associated with fewer adverse metabolic reactions. However, diuretics have a specific activity of removing sodium from the body fluid, thereby rendering the blood pressure insensitive to sodium intake, relieving the overload to systemic circulation, and normalizing the circadian rhythm of blood pressure from a non-dipper to a dipper pattern. At low doses, diuretics are known to be as effective as all other antihypertensive agents for reducing nearly all types of cardiovascular events. In this brief review, the indication for thiazide diuretics will be discussed based on the pathophysiology of hypertension and antihypertensive therapy with diuretics mainly from the point of view of sodium metabolism. Low-dose diuretics will continue to be an important agent in the treatment of hypertension, mostly in combination with vasodilators such as modulators of the reninangiotensin system and calcium channel blockers.