Hypertension in diabetes

Diabetes mellitus, a disease that affects hundreds of millions of people worldwide, is increasing in prevalence in all age groups, including children and adolescents. Much of the morbidity and mortality associated with diabetes is closely related to hypertension, often coincident with diabetes. Comorbid hypertension and diabetes often worsen the outcomes of each other, likely rooted in some overlapping pathogenic mechanisms. In this educational review, we will discuss the shared pathophysiology of diabetes and hypertension, particularly in regard to inflammation and oxidative stress, the sympathetic nervous system, vascular remodeling, and the renin-angiotensin-aldosterone system (RAAS). We will also review current hypertension diagnosis and management guidelines from many international jurisdictions for both adult and paediatric populations in the setting of diabetes. Many of these guidelines highlight the use and utility of RAAS blockers in this clinical scenario; however, on review of the evidence for their use, several meta-analyses and systematic reviews fail to demonstrate superiority of RAAS blockers over other anti-hypertensive medications. Finally, we discuss several new anti-hypertensive medications, review their mechanisms of action, and highlight some of the evidence for their use in the setting of hypertension and diabetes.

Lupus nephropathy beyond immunosuppression: Searching for nephro and cardioprotection

Renal involvement in systemic lupus erythematosus (SLE) represents one of the most frequent organ manifestations, often leading to end-stage kidney disease (ESKD). Several therapies have been tested in patients with lupus nephritis (LN) to prevent further organ damage. The effectiveness of immunosuppressive therapy as a treatment for LN is abundant, supported by multiple clinical trials that have shown its efficacy in preventing the development of chronic kidney disease (CKD). In addition to immunosuppressive therapy, several traditional and recent therapies aimed at nephroprotection in patients with proteinuric chronic kidney disease are gaining importance in the setting of LN. Thus, immunosuppressive therapy should be accompanied by nephro- and cardioprotective measures to control cardiovascular risk factors and proteinuria to ensure a better renal prognosis. Despite this, the literature on these specific measures is relatively scarce, with recommendations focused on the blockade of the renin-angiotensin-aldosterone system (RAAS). This review explores the pharmacological options available for cardiovascular and renal protection outside the usual treatment schemes.

Atherosclerotic Renovascular Disease: A KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference

The diagnosis and management of atherosclerotic renovascular disease (ARVD) is complex and controversial. Despite evidence from the ASTRAL (2009) and CORAL (2013) randomized controlled trials showing that percutaneous renal artery revascularization did not improve major outcomes compared with best medical therapy alone over 3-5 years, several areas of uncertainty remain. Medical therapy, including statin and antihypertensive medications, has evolved in recent years, and the use of renin-angiotensin-aldosterone system blockers is now considered the primary means to treat hypertension in the setting of ARVD. However, the criteria to identify kidneys with renal artery stenosis that have potentially salvageable function are evolving. There are also data suggesting that certain high-risk populations with specific clinical manifestations may benefit from revascularization. Here, we provide an overview of the epidemiology, diagnosis, and treatment of ARVD based on consensus recommendations from a panel of physician experts who attended the recent KDIGO (Kidney Disease: Improving Global Outcomes) Controversies Conference on central and peripheral arterial diseases in chronic kidney disease. Most focus is provided for contentious issues, and we also outline aspects of investigation and management of ARVD that require further research.

Effect of ramipril on kidney, lung and heart ACE2 in a diabetic mice model

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current coronavirus disease 2019 (COVID-19). The main organ affected in this infection is the lung and the virus uses the angiotensin-converting enzyme 2 (ACE2) as a receptor to enter the target cells. In this context, a controversy raised regarding the use of renin-angiotensin system (RAAS) blockers, as these drugs might increase ACE2 expression in some tissues and potentially increase the risk for SARS-CoV-2 infection. This is specially concerning in diabetic patients as diabetes is a risk factor for COVID-19.

METHODS

12-week old diabetic mice (db/db) were treated with ramipril, or vehicle control for 8 weeks. Non-diabetic db/m mice were included as controls. ACE2 expression and activity were studied in lung, kidney and heart of these animals.

RESULTS

Kidney ACE2 activity was increased in the db/db mice as compared to the db/m (143.2% ± 23% vs 100% ± 22.3%, p = 0.004), whereas ramipril had no significant effect. In the lung, no differences were found in ACE2 when comparing db/db mice to db/m and ramipril also had no significant effect. In the heart, diabetes decreased ACE2 activity (83% ± 16.8%, vs 100% ± 23.1% p = 0.02), and ramipril increased ACE2 significantly (83% ± 16.8% vs 98.2% ± 15%, p = 0.04).

CONCLUSIONS

In a mouse model of type 2 diabetes, ramipril had no significant effect on ACE2 activity in either kidneys or in the lungs. Therefore, it is unlikely that RAAS blockers or at least angiotensin-converting enzyme inhibitors increase the risk of SARS-CoV-2 infection through increasing ACE2.

Trends in Kidney Function Outcomes Following RAAS Inhibition in Patients With Heart Failure With Reduced Ejection Fraction

RATIONALE & OBJECTIVE

Angiotensin-converting enzyme (ACE) inhibitors are beneficial in heart failure with reduced ejection fraction (HFrEF). We sought to describe longitudinal trends in estimated glomerular filtration rate (eGFR) in HFrEF and how ACE-inhibitor therapy influences these changes.

STUDY DESIGN

Post hoc analysis of trial data.

SETTINGS & PARTICIPANTS

Symptomatic (Treatment Trial, n=2,423) and asymptomatic (Prevention Trial, n=4,094) patients from the Studies of Left Ventricular Dysfunction (SOLVD).

EXPOSURE

Enalapril versus placebo.

OUTCOMES

Early and long-term eGFR slope (ie, within and after the first 6 weeks) and 4 kidney end points: (1) serum creatinine level increase by≥0.3mg/dL, (2)>30% eGFR decline, (3)>40% eGFR decline, and (4) incident eGFR<30mL/min/1.73m².

ANALYTICAL APPROACH

Shared parameter models, multivariable Cox regression models.

RESULTS

Baseline mean eGFR was lower in the Treatment Trial than in the Prevention Trial, 69.5±19.8 (SD) versus 76.2±18.6mL/min/1.73m². Following randomization, an early eGFR decline occurred in the enalapril group; however, slopes during the median 3-year follow-up were not statistically different by randomization arm in either the Treatment Trial (-0.84 in enalapril vs-1.36mL/min/1.73m² per year in placebo; P=0.08) or Prevention Trial (-1.27 in enalapril vs-1.36mL/min/1.73m² per year in placebo; P=0.7). Random assignment to enalapril treatment increased the risk for all 4 outcomes in the Treatment Trial in the first 6-week period (HRs were 1.48 [95% CI, 1.10-1.99] for creatinine increase by≥0.3mg/dL; 1.38 [95% CI, 0.98-1.94] for eGFR decline> 30%; 2.60 [95% CI, 1.30-5.21] for eGFR decline> 40%; and 4.71 [95% CI, 1.78-12.50] for eGFR<30mL/min/1.73m²), but after the first year was not significantly associated with increased risk. A similar albeit less pronounced pattern was observed in the Prevention Trial, with risks present only in the early period.

LIMITATIONS

Creatinine results were not blinded, making it possible that ACE-inhibitor/placebo dosing was influenced by creatinine level.

CONCLUSION

Kidney function decline is slow in HFrEF. Although random assignment to enalapril treatment results in a statistically increased risk for kidney surrogates, the risk is limited to the early phase and late eGFR slopes and risks are not different by randomly assigned group.

[CME: Nephrotic Syndrome in Adults: Presentation, Diagnosis, Therapy]

CME: Nephrotic Syndrome in Adults: Presentation, Diagnosis, Therapy Abstract. The nephrotic syndrome is defined by renal protein loss with hypalbuminaemia and edema. Hyperlipoproteinemia and thrombophilia are not diagnostic criteria, but are frequently associated conditions. Patients with nephrotic syndrome are at higher risk for infections. Primary causes of a nephrotic syndrome are differentiated from secondary glomerulopathies due to systemic diseases. To confirm the diagnosis and for prognostic reasons, a kidney biopsy is performed in most cases. Steroids and other immunosuppressive agents are frontline therapies in primary forms. Secondary forms are treated by addressing the underlying disease. Therapeutic cornerstones include an adequate RAAS blockade with ACE inhibitors or AT-II receptor blockers. Loop diuretics are used to control edemas. In addition, the need for anticoagulation and statin therapy must be evaluated.

Management of Traditional Cardiovascular Risk Factors in CKD: What Are the Data?

Patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) are 10 times more likely to die of cardiovascular (CV) diseases than the general population, and dialysis-dependent patients are at even higher risk. Although traditional CV risk factors are highly prevalent in individuals with CKD, these patients were often excluded from studies targeting modification of these risks. Although treatment of hypertension is beneficial in CKD, the best target blood pressure has not been established. Trial data showed that renin-angiotensin-aldosterone blockade may prevent CV events in patients with CKD. The risks of aspirin may equal the benefits in NDD-CKD samples, and there are no trials testing aspirin in dialysis-dependent patients. Lipid-lowering therapy improves CV outcomes in NDD-CKD, but not in dialysis-dependent patients. Strict glycemic control prevents CV events in nonalbuminuric individuals, but showed no benefit in those with baseline albuminuria with albumin excretion > 300mg/g, and there are no data in dialysis-dependent patients. Data for lifestyle modifications, such as weight loss, physical activity, and smoking cessation, are mostly observational and extrapolated from non-CKD samples. This comprehensive review summarizes the best existing evidence and current clinical guidelines for modification of traditional risk factors for the prevention of CV events in patients with CKD and identifies knowledge gaps.

A family case of X-linked Alport syndrome patients with a novel variant in COL4A5

We herein report 2 Japanese patients with X-linked Alport syndrome (XLAS), with a novel variant in COL4A5. Patient 1 was a 16-year-old Japanese girl with a history of microscopic hematuria, without proteinuria, renal dysfunction, deafness, or ocular abnormalities. At 13 years of age, renal biopsy was performed; however, a diagnosis of AS was not considered. When her mother (patient 2) was 40 years of age (3 years after patient 1 underwent a renal biopsy), patient 2 was found to have asymptomatic hematuria, proteinuria, and an increased serum creatinine level, without deafness and ocular abnormalities. Subsequently, immunofluorescence staining for alpha 5 chains of type IV collagen was performed in patient 1. Pathological findings were consistent with AS, and genetic analysis demonstrated that both patients had a heterozygous mutation in COL4A5 (NM_000495.4: exon41:c.C3769T: p.Q1257X). To date, more than 900 different COL4A5 mutations have been identified; however, this variant has not been previously described. Physicians have to consider AS when they perform a renal biopsy in all patients with hematuria despite absent/present of family history, hearing loss, and ocular abnormality. Especially, when findings of light microscopy and immunofluorescence microscope are unclear, it should be considered carefully. Electron microscopy findings are very important.

[Cardiovascular protection of diabetic patient with chronic renal disease and particular case of end-stage renal disease in elderly patients]

Type 2 diabetes has an increasing prevalence. Life expectancy is dominated by cardiovascular risk, which is the leading cause of death in these patients. Up to one third of diabetic patients will develop diabetic nephropathy related to micro-angiopathy. Renal impairment further increases cardiovascular risk. Reducing cardiovascular morbidity and mortality is a major public health issue, as well as early preventing and managing chronic kidney disease (CKD). Good glycemic control prevents the micro-vascular complications of the disease (retinopathy, nephropathy, etc.) and, more recently recognized through prolonged monitoring of the VADT cohort, prevents cardiovascular complications. Control of blood pressure and dyslipidemia are essential in primary or secondary cardiovascular prevention. In addition, the blockers of the renin-angiotensin system slow down the progression of the MRC. Elderly patients with chronic kidney disease (CKD) form another growing group of the nephrologist daily patient pool. Especially for very elderly patients with comorbidities, the question of favoring conservative treatment rather than starting or pursuing dialysis may arise. Survival and quality of life are indeed not necessarily better in elderly patients undergoing dialysis, complications can occur eventually leading to discontinuation, and are occasionally associated with a feeling of stubbornness. Creation of prognostic score is a useful tool to help the decision-making process. However, dialogue with the patient and his/her family, as well as multidisciplinary collaboration remain fundamentals to determine the most suitable care.

Use of Renin-Angiotensin System Blockade in Advanced CKD: An NKF-KDOQI Controversies Report

Multiple clinical trials have demonstrated that renin-angiotensin system (RAS) blockade with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers effectively reduces chronic kidney disease (CKD) progression. However, most clinical trials excluded participants with advanced CKD (ie, estimated glomerular filtration rate [eGFR]<30mL/min/1.73m²). It is acknowledged that initiation of RAS blockade is often associated with an acute reduction in eGFR, which is thought to be functional, but may result in long-term preservation of kidney function through the reductions in glomerular intracapillary pressure conferred by these agents. In this National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) report, we discuss the controversies regarding use of RAS blockade in patients with advanced kidney disease. We review available published data on this topic and provide perspective on the impact of RAS blockade on changes in eGFRs and potassium levels. We conclude that more research is needed to evaluate the therapeutic index of RAS blockade in patients with advanced CKD.

Revisiting RAAS blockade in CKD with newer potassium-binding drugs

Among patients with proteinuric chronic kidney disease (CKD), current guideline recommendations mandate the use of agents blocking the renin angiotensin aldosterone system (RAAS) as first-line antihypertensive therapy based on randomized trials demonstrating that RAAS inhibitors are superior to other antihypertensive drug classes in slowing nephropathy progression to end-stage renal disease. However, the opportunities for adequate RAAS blockade in CKD are often limited, and an important impediment is the risk of hyperkalemia, especially when RAAS inhibitors are used in maximal doses or are combined. Accordingly, a large proportion of patients with proteinuric CKD may not have the anticipated renoprotective benefits since RAAS blockers are often discontinued due to incident hyperkalemia or are administered at suboptimal doses for fear of the development of hyperkalemia. Two newer potassium binders, patiromer and sodium zirconium cyclosilicate (ZS-9), have been shown to effectively and safely reduce serum potassium levels and maintain long-term normokalemia in CKD patients receiving background therapy with RAAS inhibitors. Whether these novel potassium-lowering therapies can overcome the barrier of hyperkalemia and enhance the tolerability of RAAS inhibitor use in proteinuric CKD awaits randomized trials.

Individual long-term albuminuria exposure during angiotensin receptor blocker therapy is the optimal predictor for renal outcome

BACKGROUND

Albuminuria reduction due to angiotensin receptor blockers (ARBs) predicts subsequent renoprotection. Relating the initial albuminuria reduction to subsequent renoprotection assumes that the initial ARB-induced albuminuria reduction remains stable during follow-up. The aim of this study was to assess individual albuminuria fluctuations after the initial ARB response and to determine whether taking individual albuminuria fluctuations into account improves renal outcome prediction.

METHODS

Patients with diabetes and nephropathy treated with losartan or irbesartan in the RENAAL and IDNT trials were included. Patients with >30% reduction in albuminuria 3 months after ARB initiation were stratified by the subsequent change in albuminuria until Month 12 in enhanced responders (>50% albuminuria reduction), sustained responders (between 20 and 50% reduction), and response escapers (<20% reduction). Predictive performance of the individual albuminuria exposure until Month 3 was compared with the exposure over the first 12 months using receiver operating characteristics (ROC) curves.

RESULTS

Following ARB initiation, 388 (36.3%) patients showed an >30% reduction in albuminuria. Among these patients, the albuminuria level further decreased in 174 (44.8%), remained stable in 123 (31.7%), and increased in 91 (23.5%) patients. Similar albuminuria fluctuations were observed in patients with <30% albuminuria reduction. Renal risk prediction improved when using the albuminuria exposure during the first 12 months versus the initial Month 3 change [ROC difference: 0.78 (95% CI 0.75-0.82) versus 0.68 (0.64-0.72); P < 0.0001].

CONCLUSIONS

Following the initial response to ARBs, a large within-patient albuminuria variability is observed. Hence, incorporating multiple albuminuria measurements over time in risk algorithms may be more appropriate to monitor treatment effects and quantify renal risk.

The Beneficial Effect of Renin-Angiotensin-Aldosterone System Blockade in Marfan Syndrome Patients after Aortic Root Replacement

PURPOSE

In this study, we evaluated the long term beneficial effect of Renin-Angiotensin-Aldosterone System (RAAS) blockade therapy in treatment of Marfan aortopathy.

MATERIALS AND METHODS

We reviewed Marfan syndrome (MFS) patients who underwent aortic root replacement (ARR) between January 1996 and January 2011. All patients were prescribed β-blockers indefinitely. We compared major aortic events including mortality, aortic dissection, and reoperation in patients without RAAS blockade (group 1, n=27) to those with (group 2, n=63). The aortic growth rate was calculated by dividing the diameter change on CT scans taken immediately post-operatively and the latest scan available.

RESULTS

There were no differences in clinical parameters except for age which was higher in patients with RAAS blockade. In group 1, 2 (7%) deaths, 5 (19%) aortic dissections, and 7 (26%) reoperations occurred. In group 2, 3 (5%) deaths, 2 (3%) aortic dissections, and 3 (5%) reoperations occurred. A Kaplan-Meier plot demonstrated improved survival free from major aortic events in group 2. On multivariate Cox, RAAS blockade was an independent negative predictor of major aortic events (hazard ratio 0.38, 95% confidence interval 0.30-0.43, p=0.002). Mean diameter change in descending thoracic and supra-renal abdominal aorta was significantly higher in patients without RAAS blockade (p<0.05).

CONCLUSION

In MFS patients who underwent ARR, the addition of RAAS blockade to β-blocker was associated with reduction of aortic dilatation and clinical events.

Hypertension in Chronic Glomerulonephritis

Chronic glomerulonephritis (GN), which includes focal segmental glomerulosclerosis and proliferative forms of GN such as IgA nephropathy, increases the risk of hypertension. Hypertension in chronic GN is primarily volume dependent, and this increase in blood volume is not related to the deterioration of renal function. Patients with chronic GN become salt sensitive as renal damage including arteriolosclerosis progresses and the consequent renal ischemia causes the stimulation of the intrarenal renin-angiotensin-aldosterone system(RAAS). Overactivity of the sympathetic nervous system also contributes to hypertension in chronic GN. According to the KDIGO guideline, the available evidence indicates that the target BP should be ≤140mmHg systolic and ≤90mmHg diastolic in chronic kidney disease patients without albuminuria. In most patients with an albumin excretion rate of ≥30mg/24 h (i.e., those with both micro-and macroalbuminuria), a lower target of ≤130mmHg systolic and ≤80mmHg diastolic is suggested. The use of agents that block the RAAS system is recommended or suggested in all patients with an albumin excretion rate of ≥30mg/ 24 h. The combination of a RAAS blockade with a calcium channel blocker and a diuretic may be effective in attaining the target BP, and in reducing the amount of urinary protein excretion in patients with chronic GN.

Diabetic nephropathy: What does the future hold?

The consensus management of diabetic nephropathy (DN) in 2015 involves good control of glycaemia, dyslipidaemia and blood pressure (BP). Blockade of the renin-angiotensin-aldosterone system using angiotensin-converting enzyme inhibitors, angiotensin-2 receptor blockers or mineralocorticoid inhibitors are key therapeutic approaches, shown to be beneficial once overt nephropathy is manifest, as either, or both, of albuminuria and loss of glomerular filtration rate. Some significant additional clinical benefits in slowing the progression of DN was reported from the Remission clinic experience, where simultaneous intensive control of BP, tight glycaemic control, weight loss, exercise and smoking cessation were prioritised in the management of DN. This has not proved possible to translate to more conventional clinical settings. This review briefly looks over the history and limitations of current therapy from landmark papers and expert reviews, and following an extensive PubMed search identifies the most promising clinical biomarkers (both established and proposed). Many challenges need to be addressed urgently as in order to obtain novel therapies in the clinic; we also need to examine what we mean by remission, stability and progression of DN in the modern era.