Resistant hypertension in nondialysis chronic kidney disease

Role of Nutrients in Pediatric Non-Dialysis Chronic Kidney Disease: From Pathogenesis to Correct Supplementation

Nutrition management is fundamental for children with chronic kidney disease (CKD). Fluid balance and low-protein and low-sodium diets are the more stressed fields from a nutritional point of view. At the same time, the role of micronutrients is often underestimated. Starting from the causes that could lead to potential micronutrient deficiencies in these patients, this review considers all micronutrients that could be administered in CKD to improve the prognosis of this disease.

Thiazide diuretics are back in CKD: the case of chlorthalidone

Sodium and volume excess is the fundamental risk factor underlying hypertension in chronic kidney disease (CKD) patients, who represent the prototypical population characterized by salt-sensitive hypertension. Low salt diets and diuretics constitute the centrepiece for blood pressure control in CKD. In patients with CKD stage 4, loop diuretics are generally preferred to thiazides. Furthermore, thiazide diuretics have long been held as being of limited efficacy in this population. In this review, by systematically appraising published randomized trials of thiazides in CKD, we show that this class of drugs may be useful even among people with advanced CKD. Thiazides cause a negative sodium balance and reduce body fluids by 1-2 l within the first 2-4 weeks and these effects go along with improvement in hypertension control. The recent CLICK trial has documented the antihypertensive efficacy of chlorthalidone, a long-acting thiazide-like diuretic, in stage 4 CKD patients with poorly controlled hypertension. Overall, chlorthalidone use could be considered in patients with treatment-resistant hypertension when spironolactone cannot be administered or must be withdrawn due to side effects. Hyponatremia, hypokalaemia, volume depletion and acute kidney injury are side effects that demand a vigilant attitude by physicians prescribing these drugs. Well-powered randomized trials assessing hard outcomes are still necessary to more confidently recommend the use of these drugs in advanced CKD.

Effects of Sacubitril/Valsartan on resistant hypertension and myocardial work in hemodialysis patients

Growing evidences have confirmed the effect of Sacubitril/Valsartan (SV) on antihypertension and cardiac protection in general population. However, there was no prospective study about the effect and safety of SV on resistant hypertension and myocardial work in hemodialysis patients. In this single‐center, prospective, before‐after study, enrolled patients were endured with resistant hypertension for more than 6 months. Participants were initially instructed to take SV 50 mg twice daily, and the dosage was gradually increased up to 100 mg twice daily. The primary outcomes were blood pressure (BP) control, N‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP), myocardial work (MW), fatigue and life quality. In addition, the adverse events were also recorded in this cohort. A total of 18 patients (34–64 years old) was finally enrolled and completed in this study. The SV‐based regimen provided significantly mean sitting systolic BP (msSBP) and mean sitting diastolic BP (msDBP) reductions from baseline (‐20.7/‐8.3 mm Hg), respectively. The cardiac remodeling parameters were partially improved. Compared to the baseline, NT‐proBNP was significantly reduced at week 4 (8119.50 [3710.75, 29300] pg/ml to 7216.50 [4124.75, 17455.00] pg/ml, p = .046), which was much lower at week 12 (3130.50 [2244.50, 9565.70] pg/ml, p = .037). Global MW index was higher at week 12 compared to the baseline (p = .026). MW efficiency was also improved accordingly compared to the baseline, even though the statistical difference was not significant (p = .226). Life quality and fatigue were improved at week 12 compared to the baseline (all p = .000). There was no serious adverse events were observed. SV safely and effectively controlled resistant hypertension and improved MW as well as life quality in hemodialysis patients.

Mild sodium reduction in peritoneal dialysis solution improves hypertension in end stage kidney disease: a case-report study

Introduction

Blood Pressure (BP) control is largely unsatisfied in End Stage Kidney Disease (ESKD) principally due to sodium retention. Peritoneal Dialysis (PD) is the most common type of home dialysis, using a peritoneal membrane to remove sodium, though sodium removal remains challenging.

Methods

This is a case-study reporting two consecutive ESKD patients treated by a novel peritoneal PD solution with a mildly reduced sodium content (130 mmol/L) to treat hypertension.

Results

In the first case, a 78-year-old woman treated by Continuous Ambulatory PD (CAPD) with standard solution (three 4 h-dwells per day 1.36% glucose 132 mmol/L) showed resistant hypertension confirmed by ambulatory blood pressure monitoring (ABPM), reporting 24 h-BP: 152/81 mmHg, day-BP:151/83 mmHg and night-ABP: 153/75 mmHg, with inversion of the circadian systolic BP rhythm (1.01), despite use of three anti-hypertensives and a diuretic at adequate doses. No sign of hypervolemia was evident. We then switched from standard PD to low-sodium solution in all daily dwells. A six-months low-sodium CAPD enabled us to reduce diurnal (134/75 mmHg) and nocturnal BP (122/67 mmHg), restoring the circadian BP rhythm, with no change in ultrafiltration or residual diuresis. Diet and drug prescription were unmodified too.

The second case was a 61-year-old woman in standard CAPD (three 5 h-dwells per day) suffering from hypertension confirmed by ABPM (mean 24 h-ABP: 139/84 mmHg; mean day-ABP:144/88 mmHg and mean night-ABP:124/70 mmHg). She was switched from 132-Na CAPD to 130-Na CAPD, not changing dialysis schedule. No fluid expansion was evident. During low-sodium CAPD, antihypertensive therapy (amlodipine 10 mg and Olmesartan 20 mg) has been reduced until complete suspension. After 6 months, we repeated ABPM showing a substantial reduction in mean 24 h-ABP (117/69 mmHg), mean diurnal ABP (119/75 mmHg) and mean nocturnal ABP (111/70 mmHg). Ultrafiltration and residual diuresis remained unmodified. No side effects were reported in either cases.

Conclusions

This case-report study suggests that mild low-sodium CAPD might reduce BP in hypertensive ESKD patients.

Relationship between blood pressure and kidney diseases in large randomized controlled trials: secondary analyses using SPRINT and ACCORD-BP trials

Hypertension is a risk factor for acute kidney injury. In this study, we aimed to identify the optimal blood pressure (BP) targets for CKD and non-CKD patients. We analyzed the data of the Systolic Blood Pressure Intervention Trial (SPRINT) and the Action to Control Cardiovascular Risk in Diabetes Blood Pressure trial (ACCORD BP) to determine the nonlinear relationship between BP and renal disease development using the Generalized Additive Model (GAM). Optimal systolic BP/diastolic BP (SBP/DBP) with lowest renal risk were estimated using GAM. Logistic regression was employed to find odds ratios (ORs) of adverse renal outcomes by three BP groups (high/medium/low). Both study trials have demonstrated a "U"-shaped relationship between BP and renal outcomes. For non-CKD patients in SPRINT trial, risk of 30% reduction in eGFR among intensive group patients with DBP ≤ 70 mmHg was significantly higher than the group with DBP between 71 and 85 mmHg (OR = 2.31, 95% CI = 1.51-3.53). For non-CKD patients in ACCORD trial, risk of doubling of serum creatinine (SCr) or >20 mL/min decrease in eGFR among intensive group patients with DBP ≤ 70 mmHg was significantly higher than the group with DBP between 71 and 85 mmHg (OR = 1.49, 95% CI = 1.12-1.99). For CKD patients in SPRINT trial, there are no significant differences in renal outcomes by different SBP/DBP levels. Our analysis of both SPRINT and ACCORD datasets demonstrated that lower-than-optimal DBP may lead to poor renal outcomes in non-CKD patients. Healthcare providers should be cautious of too low DBP level in intensive BP management due to poor renal outcomes for non-CKD patients.

Sodium Intake and Chronic Kidney Disease

In Chronic Kidney Disease (CKD) patients, elevated blood pressure (BP) is a frequent finding and is traditionally considered a direct consequence of their sodium sensitivity. Indeed, sodium and fluid retention, causing hypervolemia, leads to the development of hypertension in CKD. On the other hand, in non-dialysis CKD patients, salt restriction reduces BP levels and enhances anti-proteinuric effect of renin-angiotensin-aldosterone system inhibitors in non-dialysis CKD patients. However, studies on the long-term effect of low salt diet (LSD) on cardio-renal prognosis showed controversial findings. The negative results might be the consequence of measurement bias (spot urine and/or single measurement), reverse epidemiology, as well as poor adherence to diet. In end-stage kidney disease (ESKD), dialysis remains the only effective means to remove dietary sodium intake. The mismatch between intake and removal of sodium leads to fluid overload, hypertension and left ventricular hypertrophy, therefore worsening the prognosis of ESKD patients. This imposes the implementation of a LSD in these patients, irrespective of the lack of trials proving the efficacy of this measure in these patients. LSD is, therefore, a rational and basic tool to correct fluid overload and hypertension in all CKD stages. The implementation of LSD should be personalized, similarly to diuretic treatment, keeping into account the volume status and true burden of hypertension evaluated by ambulatory BP monitoring.

Atherosclerotic-nephropathy: an updated narrative review

The increased prevalence of chronic kidney disease (CKD) in elderly patients recognizes, as main cause, the long-term exposure to atherosclerosis and hypertension. Chronic ischemic damage due to critical renal arterial stenosis induces oxidative stress and intra-renal inflammation, resulting in fibrosis and microvascular remodelling, that is the histological picture of atherosclerotic renal vascular disease (ARVD). The concomitant presence of a long history of hypertension may generate intimal thickening and luminal narrowing of renal arteries and arterioles, glomerulosclerosis, interstitial fibrosis and tubular atrophy, more typically expression of hypertensive nephropathy. These complex mechanisms contribute to the development of CKD and the progression to End Stage Kidney Disease. In elderly CKD patients, the distinction among these nephropathies may be problematic; therefore, ischemic and hypertensive nephropathies can be joined in a unique clinical syndrome defined as atherosclerotic nephropathy. The availability of novel diagnostic procedures, such as intra-vascular ultrasound and BOLD-MRI, in addition to traditional imaging, have opened new scenarios, because these tools allow to identify ischemic lesions responsive to renal revascularization. Indeed, although trials have deflated the role of renal revascularization on the renal outcomes, it should be still used to avoid dialysis initiation and/or to reduce blood pressure in selected elderly patients at high risk. Nonetheless, lifestyle modifications (smoking cessation, increased physical activity), statins and antiplatelet use, as well as cautious use of renin-angiotensin system inhibitors, remain the main therapeutic approach aimed at slowing the renal damage progression. Mesenchymal stem cells and Micro-RNA are promising target of anti-fibrotic therapy, which might provide potential benefit in ARVD patients, though safety and efficacy profile in humans is unknown too.

Sodium toxicity in peritoneal dialysis: mechanisms and "solutions"

The major trials in peritoneal dialysis (PD) have demonstrated that increasing peritoneal clearance of small solutes is not associated with any advantage on survival, whereas sodium and fluid overload heralds higher risk of death and technique failure. On the other hand, higher sodium and fluid overload due to loss of residual kidney function (RKF) and higher transport membrane is associated with poor patient and technique survival. Recent experimental studies also show that, independently from fluid overload, sodium accumulation in the peritoneal interstitium exerts direct inflammatory and angiogenetic stimuli, with consequent structural and functional changes of peritoneum, while in patients with Chronic Kidney Disease sodium stored in interstitial skin acts as independent determinant of left ventricular hypertrophy. Noteworthy, this tissue pool of sodium is modifiable being removed by dialysis. Therefore, novel PD strategies to optimize sodium removal, including the use of bimodal and/or low-sodium solutions, are actively tested. Nonetheless, a holistic approach aimed at preserving peritoneal function and the kidney may represent the key of therapy success in the hard task of preserving adequate sodium balance in PD patients. In this review, we describe the available evidence on sodium toxicity in PD, either related or unrelated to fluid overload, and we also discuss about possible "solutions" to preserve or restore sodium balance in PD patients.

Resistant Hypertension: Mechanisms and Treatment

PURPOSE OF REVIEW

Emerging evidence suggests that multiple mechanisms may be responsible for the development of treatment-resistant hypertension (TRH). This review aims to summarize recent data on potential mechanisms of resistance and discuss current pharmacotherapeutic options available in the management of TRH.

RECENT FINDINGS

Excess sodium and fluid retention, increased activation of the renin-angiotensin-aldosterone system, and heightened activity of the sympathetic nervous system appear to play an important role in development of TRH. Emerging evidence also suggests a role for arterial stiffness and, potentially, gut dysbiosis. Therapeutic approaches for TRH should include diuretic optimization and the addition of aldosterone antagonists as the preferred fourth agent in most patients. Further therapeutic approaches may be guided by the suspected underlying mechanism of TRH in conjunction with other patient-specific factors. The pathophysiology of TRH is multifaceted; however, increasing evidence supports several mechanisms that may be targeted to improve blood pressure control among patients with TRH. Further studies are needed to determine whether such approaches may be more effective than usual care.

Gut-Brain Axis in Regulation of Blood Pressure

Hypertension (HTN) is an escalating health issue worldwide. It is estimated that 1.56 billion people will suffer from high blood pressure (BP) by 2025. Recent studies reported an association between gut dysbiosis and HTN, thus proposing interesting avenues for novel treatments of this condition. The sympathetic nervous system (SNS) and the immune system (IS) play a recognized role in the onset and progression of HTN, while reciprocal communication between gut microbiota and the brain can regulate BP by modulating the interplay between the IS and SNS. This review presents the current state of the science implicating brain-gut connection in HTN, highlighting potential pathways of their interaction in control of BP.

Antihypertensive drug prescription patterns and their impact on outcome of blood pressure in Ethiopia: a hospital-based cross-sectional study

Background

Irrational prescription is strongly associated with poor control of hypertension. The present study aimed to evaluate antihypertensive drug prescription trends and to measure their impact on the level of blood pressure (BP) control in Gondar University Hospital, Gondar, Ethiopia.

Methods

A hospital-based retrospective cross-sectional study was conducted from May 30 to June 30, 2016. All hypertensive patients on medication were included. A structured data abstraction form was prepared to gather the necessary information. The prescription patterns and BP level were measured retrospectively. A binary logistic regression was computed to determine the effect of different prescription patterns on BP control.

Results

A total of 596 hypertension patients were recruited for the study; of them, 561(94%) met the study criteria. The mean age of the respondents was 55.96±14.6 years. Females constituted 58.2% of the study population. Approximately fifty percent of the prescriptions were monotherapies. Twice-daily dosing was associated with lower risk of uncontrolled hypertension (crude odds ratio [COR] =0.51[0.15–0.73], adjusted odds ratio [AOR] =0.69[0.163–0.91]). Monthly appointment was linked with a nearly 90% reduced incidence of uncontrolled BP (COR =0.15[0.04–0.73], AOR =0.093[0.024–0.359]).

Conclusion

Monotherapies were the most frequently prescribed regimens. Twice-daily dosing and monthly appointments were associated with low incidence of uncontrolled BP. Clinicians should be vigilant in adjusting the frequency of dosing and should fix appointment date in consultation with their patients.

Asymptomatic hyperuricemia is a strong risk factor for resistant hypertension in elderly subjects from general population

OBJECTIVE

In clinical practice, patient characteristics predicting resistant hypertension (RH) include higher blood pressure levels, left ventricular hypertrophy, older age, obesity, chronic kidney disease and diabetes. On the contrary little is known about the role of serum uric acid (SUA) as a risk factor for RH in subjects from general population.

MATERIAL AND METHODS

580 elderly subjects aged ≥65 years were enrolled in the Risk Of Vascular complications Impact of Genetics in Old people (ROVIGO) study. RH was defined as the failure to maintain blood pressure values below 140mmHg (systolic) and 90mmHg (diastolic) despite therapeutic interventions that include appropriate lifestyle measures plus adherence to treatment with full doses of at least three antihypertensive drugs, including a diuretic. RH was confirmed using 24-h ambulatory blood pressure measurement. Hyperuricemic was defined as the subjects having SUA ≥6.8mg/dl or taking uricosuric drugs. Gender-specific odds ratio (OR) for RH was calculated by logistic regression analysis.

RESULTS

The prevalence of RH was 5.7% in the cohort and was higher in women (8.3%) than in men (3.0%, p<0.05). Independent of chronic kidney disease (OR 3.89, 95% confidence interval 1.49-10.1), hyperuricemia predicted resistant hypertension in women (odds ratio 3.11, 95% confidence intervals 1.06-9.1, p=0.03) but not in men.

CONCLUSIONS

In elderly women from the general population, an SUA value of ≥6.8mg/dl triples the risk of RH. SUA assessment should be recommended to better define the pattern of risk associated with RH.

Association of interleukin 17 / angiotensin II with refractory hypertension risk in hemodialysis patients

OBJECTIVE

The study was performed to investigate the association of interleukin 17 (IL 17) or angiotensin II (Ang II) with refractory hypertension risk in hemodialysis patients.

METHODS

Ninety hemodialysis patients were enrolled into this study, and those with hypertension were divided into two groups. The Easy-to-Control Hypertension group (ECHG) had fifty patients, while the refractory hypertension group (RHG) had forty patients. Twenty healthy individuals were recruited as the control group. IL17 and Ang II were determined using a human IL 17 / Ang II enzyme-linked immunosorbent assay kit. Serum IL 17 and Ang II concentrations in RHG patients were higher than those in ECHG patients.

RESULTS

Serum IL 17 and Ang II concentrations in both patient groups were higher than those in the control group. Linear regression analysis showed a positive correlation between IL 17 and Ang II. In multivariate regression analysis, we found that IL17 and Ang II were associated with refractory hypertension risk in hemodialysis patients.

CONCLUSION

IL17 and Ang II were associated with refractory hypertension risk in hemodialysis patients. There was also a positive correlation between IL 17and Ang II.

Evaluation of Renal-Hepatic Functional Indices and Blood Pressure Based on the Progress of Time in a Rat Model of Chronic Kidney Disease

BACKGROUND

Chronic kidney disease (CKD) is defined as either kidney damage or a decline in renal function as determined by a decreased glomerular filtration rate (GFR) for three months or longer. CKD is an important risk factor for mortality.

OBJECTIVES

The aim of this study was to evaluate the effects of CKD on renal-hepatic functional indices and blood pressure in 5/6 nephrectomized (5/6 Nx) rats over the course of nine months.

MATERIALS AND METHODS

Male Wistar rats were subjected to either 5/6 Nx or sham operations (n = 8). Members of the sham group underwent the same procedure without surgical reduction of the kidney mass. For all animals, body weight (BW), serum creatinine (Cr), blood urea nitrogen (BUN), alanine transaminase (ALT), and aspartate transaminase (AST) levels were measured before and after surgery. After two-, three-, six-, and nine-month intervals, blood was collected to assay renal and hepatic functional indices. Tail-cuff blood pressure was recorded in each month after surgery.

RESULTS

BW was lower for the 5/6 Nx group rats after the operations compared with the BW of those in the sham operation group. Furthermore, the 5/6 Nx group showed elevations in blood pressure, Cr, BUN, ALT, and AST levels compared with the sham group over the course of time.

CONCLUSIONS

In summary, CKD induced by the 5/6 Nx model caused hypertension and increased serum levels of Cr, BUN, ALT, and AST. These changes are augmented by the progress of time.

Can Antidepressant Drug Impact on Blood Pressure Level in Patients with Psychiatric Disorder and Hypertension? A Randomized Trial

Background:

High blood pressure (BP) has been known as a major risk factor for many chronic diseases. It should be noted, a psychiatric disorder which is common in the people living modern lifestyle may be one of the leading causes of hypertension, and many people are prescribed antidepressant each year. Hence, the purpose of this study was to evaluate the effect of selective serotonin reuptake inhibitors (SSRIs) and alprazolam which defined as antidepressant on the BP levels, and to compare the BP levels between the group of users and nonusers.

Methods:

This randomized clinical trial study was conducted at the Nohom Dey Hospital in the Torbat-e Heydarieh, Iran between December 2011 and March 2012. Participants comprised 101 psychiatric patients with hypertension that randomly separated into users and nonusers of antidepressant. The period of intervention lasted for 3 months. The mean of BP calculated by this formula (systolic BP [SBP] +2 diastolic BP [DBP])/3 which was the main outcome of the study.

Results:

Users of antidepressant drugs did not have any significant changes in BP levels, except in patients who received SSRIs alone, significant improvement was observed in DBP (P = 0.04) and mean of BP (P = 0.03). While, in nonusers of antidepressant, significant development was observed in DBP, and mean of BP. Comparing the users and nonusers did not show any significant differences in SBP, DBP, and Mean of BP; even, when outcomes were adjusted for risk factors and antihypertensive drugs.

Conclusions:

Three months treatment with SSRIs and alprazolam did not have any effect on lowering BP level in patients with the psychiatric disorder.

Estimated GFR or albuminuria: which one is really associated with resistant hypertension?

Patients with resistant hypertension belong to a very high cardiovascular risk group and have a high prevalence of target organ damage. Microalbuminuria and low estimated glomerular filtration rate are associated with resistant hypertension, and could be a cause and/or complication of hypertension. In this review, we explore the relationship between these 2 markers of kidney disease and the prevalence of resistant hypertension. We identified different phenotypes of resistant hypertension that associate with microalbuminuria and/or low estimated glomerular filtration rate. These phenotypes suggest that high sympathetic activity associated with fluid overload and endothelial dysfunction may contribute differently to the development of resistant hypertension.