Preventing microalbuminuria in patients with diabetes: rationale and design of the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study

Effects of allisartan-isoproxil-based combination antihypertensive regimen in hypertensive patients with microalbuminuria or hyperuricemia

Microalbuminuria and hyperuricemia management are crucial for the integrated management of hypertensive patients. This retrospective post hoc analysis aims to evaluate the optimal allisartan-isoproxil-based combination regimen for hypertensive patients with microalbuminuria or hyperuricemia. A total of 460 hypertensive patients with microalbuminuria and 486 hypertensive patients with hyperuricemia were included in this study. All patients were initially treated with allisartan-isoproxil for 4 weeks. Thereafter, patients with blood pressure (BP) < 140/90 mmHg continued the monotherapy for 8 weeks; patients with BP ≥140/90 mmHg were randomly assigned in a 1:1 ratio to receive allisartan-isoproxil + amlodipine (Group A + C) or allisartan-isoproxil + indapamide (Group A + D) for 8 weeks. The changes of BP, urinary albumin and serum uric acid (UA) were measured. In patients with microalbuminuria, the urinary albumin/creatinine ratio (UACR) significantly decreased by 10.4 mg/g in Group A + C (vs. baseline p = .0035) and 24.2 mg/g in Group A + D (vs baseline p < .0001), intergroup p = NS. In patients with hyperuricemia, serum UA level decreased by 44.5 µmol/L in Group A + C (vs. baseline p = .0003), but increased by 27.2 µmol/L in Group A + D (vs. baseline p = .0167), intergroup p < .0001. The results suggest that for hypertensive patients with microalbuminuria, angiotensin receptor blocker (ARB) + calcium channel blocker (CCB) or ARB+ diuretic both are good choices based on their improvement of microalbuminuria and BP. But for patients with hyperuricemia, ARB + diuretic may further increase the level of UA.

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Concurrent blood pressure control has been advocated for this purpose, but individual studies have reported varying conclusions regarding the effects of this intervention.

OBJECTIVES

To summarize the existing evidence regarding the effect of interventions to control blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs.

SEARCH METHODS

We searched several electronic databases, including CENTRAL, and trial registries. We last searched the electronic databases on 3 September 2021. We also reviewed the reference lists of review articles and trial reports selected for inclusion.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to more intense versus less intense blood pressure control; to blood pressure control versus usual care or no intervention on blood pressure (placebo); or to one class of antihypertensive medication versus another or placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed the titles and abstracts of records identified by the electronic and manual searches and the full-text reports of any records identified as potentially relevant. The included trials were independently assessed for risk of bias with respect to outcomes reported in this review.

MAIN RESULTS

We included 29 RCTs conducted in North America, Europe, Australia, Asia, Africa, and the Middle East that had enrolled a total of 4620 type 1 and 22,565 type 2 diabetic participants (sample sizes from 16 to 4477 participants). In all 7 RCTs for normotensive type 1 diabetic participants, 8 of 12 RCTs with normotensive type 2 diabetic participants, and 5 of 10 RCTs with hypertensive type 2 diabetic participants, one group was assigned to one or more antihypertensive agents and the control group to placebo. In the remaining 4 RCTs for normotensive participants with type 2 diabetes and 5 RCTs for hypertensive type 2 diabetic participants, methods of intense blood pressure control were compared to usual care. Eight trials were sponsored entirely and 10 trials partially by pharmaceutical companies; nine studies received support from other sources; and two studies did not report funding source. Study designs, populations, interventions, lengths of follow-up (range less than one year to nine years), and blood pressure targets varied among the included trials. For primary review outcomes after five years of treatment and follow-up, one of the seven trials for type 1 diabetics reported incidence of retinopathy and one trial reported progression of retinopathy; one trial reported a combined outcome of incidence and progression (as defined by study authors). Among normotensive type 2 diabetics, four of 12 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; two trials reported combined incidence and progression. Among hypertensive type 2 diabetics, six of the 10 trials reported incidence of diabetic retinopathy and two trials reported progression of retinopathy; five of the 10 trials reported combined incidence and progression. The evidence supports an overall benefit of more intensive blood pressure intervention for five-year incidence of diabetic retinopathy (11 studies; 4940 participants; risk ratio (RR) 0.82, 95% confidence interval (CI) 0.73 to 0.92; I2 = 15%; moderate certainty evidence) and the combined outcome of incidence and progression (8 studies; 6212 participants; RR 0.78, 95% CI 0.68 to 0.89; I2 = 42%; low certainty evidence). The available evidence did not support a benefit regarding five-year progression of diabetic retinopathy (5 studies; 5144 participants; RR 0.94, 95% CI 0.78 to 1.12; I2 = 57%; moderate certainty evidence), incidence of proliferative diabetic retinopathy, clinically significant macular edema, or vitreous hemorrhage (9 studies; 8237 participants; RR 0.92, 95% CI 0.82 to 1.04; I2 = 31%; low certainty evidence), or loss of 3 or more lines on a visual acuity chart with a logMAR scale (2 studies; 2326 participants; RR 1.15, 95% CI 0.63 to 2.08; I2 = 90%; very low certainty evidence). Hypertensive type 2 diabetic participants realized more benefit from intense blood pressure control for three of the four outcomes concerning incidence and progression of diabetic retinopathy. The adverse event reported most often (13 of 29 trials) was death, yielding an estimated RR 0.87 (95% CI 0.76 to 1.00; 13 studies; 13,979 participants; I2 = 0%; moderate certainty evidence). Hypotension was reported in two trials, with an RR of 2.04 (95% CI 1.63 to 2.55; 2 studies; 3323 participants; I2 = 37%; low certainty evidence), indicating an excess of hypotensive events among participants assigned to more intervention on blood pressure.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions for which lowering blood pressure has proven to be beneficial. The available evidence supports a modest beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to five years, particularly for hypertensive type 2 diabetics. However, there was a paucity of evidence to support such intervention to slow progression of diabetic retinopathy or to affect other outcomes considered in this review among normotensive diabetics. This weakens any conclusion regarding an overall benefit of intervening on blood pressure in diabetic patients without hypertension for the sole purpose of preventing diabetic retinopathy or avoiding the need for treatment for advanced stages of diabetic retinopathy.

The Treatment Effectiveness Evaluation for Slowing the Progression of Diabetic Nephropathy During Stage 4 Chronic Kidney Disease

INTRODUCTION

People with advanced diabetic nephropathy (DN) are at high risk for development of end-stage renal disease (ESRD) or death. Whether renin-angiotensin system inhibitors and some concomitant drugs could still continue to delay the onset of ESRD in the later stage of DN needs to be clarified. This study aimed to evaluate the relationship of the therapeutic methods as well as clinicopathologic variables with prognosis of patients with biopsy-proven DN during stage 4 of chronic kidney disease (CKD).

METHODS

Forty-six DN patients who underwent renal biopsy in stage 4 CKD were enrolled from January 1, 2002, to December 31, 2019. Clinical data were abstracted retrospectively from the time of renal biopsy. Follow-up data were collected until April 1, 2020, or from the day of renal biopsy to either the occurrence of ESRD or death. The primary outcome was the composite of ESRD or death. Treatment effectiveness and the prognostic ability of clinicopathologic data were evaluated using multivariate Cox regression analyses.

RESULTS

The median renal survival duration was 17.3 (95% confidence interval, 7.4-27.3 months). Primary endpoint events occurred in 29 individuals (63.0%) during follow-up, including 24 who reached ESRD and 5 who died before progression to ESRD. None of the clinicopathologic data, including pathologic cass of DN, were statistically independent prognostic factors for renal survival. Conventional therapies, such as use of renin-angiotensin system (RAS) inhibitors, a level of glycated hemoglobin (HbA1c) < 7%, and blood pressure < 130/80 mmHg, were also not statistically different between the stable and progressive groups.

CONCLUSION

Specific therapies including targeting blood pressure < 130/80 mmHg, HbA1c concentration < 7%, and use of RAS inhibitors could not effectively delay the onset of ESRD in the later stage of DN. Therefore, efforts to slow the progression of DN should focus on early diagnosis and treatment.

Differential metabolic profile associated with the condition of normoalbuminuria in the hypertensive population

BACKGROUND AND AIM

Albuminuria is an indicator of sub-clinical organ damage and a marker of cardiovascular risk and renal disease. A percentage of hypertensive patients develop albuminuria despite being under chronic suppression of the renin-angiotensin system (RAS). We previously identified urinary metabolites associated with the development of albuminuria. In this study, we searched for metabolic alterations which reflect different levels within the condition of normoalbuminuria.

PATIENTS, MATERIALS AND METHODS

Urine from 48 hypertensive patients under chronic RAS suppression was analysed. They were classified according to the albumin/creatinine ratio (ACR) into 3groups: Normoalbuminuria (<10mg/g); high-normal (10-30mg/g in men, or 20-40mg/g in women); and moderately high albuminuria (microalbuminuria, 30-200mg/g or 40-300mg/g, respectively). The metabolome was analysed by mass spectrometry and a correlation analysis was performed between altered metabolite levels and ACR.

RESULTS

Oxaloacetate, 3-ureidopropionate, guanidoacetate and malate show significant variation between the normo and micro groups. Additionally, these metabolites are able to differentiate between patients in the normo and high-normal range. A significant correlation between metabolites and ACR was found. Observed variations point to alterations in the energy metabolism already in patients with albuminuria in the high-normal range.

CONCLUSIONS

The association between the molecular panel consisting of 3-ureidopropionate, oxaloacetate, malate and guanidoacetate and different levels of albuminuria is confirmed. A metabolic fingerprint was also identified showing variations within the condition of normoalbuminuria allowing an earlier molecular stratification of patients.

Olmesartan Medoxomil, An Angiotensin II-Receptor Blocker, Ameliorates Renal Injury In db/db Mice

Background

Diabetic nephropathy (DN) is a common complication of diabetes mellitus (DM) and also a major cause of end-stage renal disease (ESRD). Olmesartan medoxomil (OM) is an angiotensin II receptor blocker (ARB) and has been shown to exhibit renoprotective effects on a streptozotocin (STZ)-induced diabetic rat model. Yet, whether OM affects DN progression and renal injury in db/db mice, a type 2 diabetic murine model, has not been established.

Methods

Wild-type (n = 15) and db/db mice (n = 15) were treated with control saline or OM via oral gavage. The physiological and biochemical parameters were evaluated and histological examinations of kidney specimens were performed.

Results

Compared with saline-treated db/db mice, db/db mice administered with OM showed ameliorated diabetic physiological and biochemical parameters. In addition, OM decreased urinary albumin excretion and plasma creatinine level in db/db mice. Moreover, histologically, OM reduced glomerular hypertrophy and injury, and also ameliorated tubular injury, thus suggesting that OM improves renal function and minimizes renal pathological deterioration in db/db mice.

Conclusion

Our study reveals a beneficial role of OM in ameliorating DN in db/db mice, which is associated with its renoprotective function.

Marketing trials, marketing tricks - how to spot them and how to stop them

Background

Last this year in this journal, Barbour and colleagues reported a study of “marketing trials” in leading medical journals (Trials 2016;17:31). In this commentary I discuss their research, describe new analyses of the study cohort and consider measures to address marketing within academic medical literature.

Discussion

Barbour et al. sought to identify a subgroup of “marketing trials” within leading medical journals, but in reality, nearly all industry-financed trials serve marketing functions, and many exhibit marketing-related features, including biases, in their framing, methodology or reporting. I conducted new analyses of the cohort of Barbour et al., showing that most trials funded exclusively by drug manufacturers had direct involvement of the manufacturer in design, analysis and reporting, and features supportive of product seeding. However, these commercial enterprises were without exception presented to journal readers as academic-led projects, using attributional spin, which should itself be considered an important form of marketing bias. Barbour et al. correctly conclude that commercial bias in industry clinical trials articles often requires expertise to recognize, and in many cases cannot be identified from the published journal report. Several potential remedies are discussed, including independent clinical research, data sharing, improved reporting guidance, improved tools for assessing research quality, reforms to article attribution, submission checklists and new editorial standards.

Conclusion

Medicine’s journals have a responsibility to uphold rigorous scientific and reporting standards, require ready trials data access and ensure the commercial dimensions of research are brought prominently to their readers’ attention. Failure to meet these responsibilities constitutes an enduring threat to the integrity of biomedical literature.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1827-5) contains supplementary material, which is available to authorized users.

Severe intestinal malabsorption associated with olmesartan: a French nationwide observational cohort study

OBJECTIVES

Severe sprue-like enteropathy associated with olmesartan has been reported, but there has been no demonstration of an increased risk by epidemiological studies.

AIM

To assess, in a nationwide patient cohort, the risk of hospitalisation for intestinal malabsorption associated with olmesartan compared with other angiotensin receptor blockers (ARB) and ACE inhibitors (ACEIs).

DESIGN

From the French National Health Insurance claim database, all adult patients initiating ARB or ACEI between 1 January 2007 and 31 December 2012 with no prior hospitalisation for intestinal malabsorption, no serology testing for coeliac disease and no prescription for a gluten-free diet product were included. Incidence of hospitalisation with a discharge diagnosis of intestinal malabsorption was the primary endpoint.

RESULTS

4 546 680 patients (9 010 303 person-years) were included, and 218 events observed. Compared with ACEI, the adjusted rate ratio of hospitalisation with a discharge diagnosis of intestinal malabsorption was 2.49 (95% CI 1.73 to 3.57, p<0.0001) in olmesartan users. This adjusted rate ratio was 0.76 (95% CI 0.39 to 1.49, p=0.43) for treatment duration shorter than 1 year, 3.66 (95% CI 1.84 to 7.29, p<0.001) between 1 and 2 years and 10.65 (95% CI 5.05 to 22.46, p<0.0001) beyond 2 years of exposure. Median length of hospital stay for intestinal malabsorption was longer in the olmesartan group than in the other groups (p=0.02). Compared with ACEI, the adjusted rate ratio of hospitalisation for coeliac disease was 4.39 (95% CI 2.77 to 6.96, p<0.0001) in olmesartan users and increased with treatment duration.

CONCLUSIONS

Olmesartan is associated with an increased risk of hospitalisation for intestinal malabsorption and coeliac disease.

[Enteropathy due to olmesartan]

The olmesartan is a selective antagonist of angiotensin II indicated for the treatment of essential hypertension. We report the case of a gastrointestinal involvement with duodenal villous atrophy and lymphocytic infiltrate duodenal epithelial and colonic secondary to the olmesartan taking with test of positive reintroduction. The patient had chronic diarrhea with weight loss of 10kg occurring one month after the passage of 20 to 40mg/day olmesartan took three years. A rectosigmoidoscopy highlighted some puncture slightly erythematous areas. The responsibility of olmesartan was suspected and the drug was stopped. The evolution was rapidly favorable with disappearance of diarrhea 48hours later. Two days after the patient took the drug on its own initiative. Sigmoid biopsies showed an inflammatory infiltrate rich in lymphocytes. Gastroscopy showed erosive esophagitis and duodenal biopsies showed chronic duodenitis with epithelial lymphocytosis and subtotal villous atrophy. The reintroduction has led to the immediate resumption of diarrhea. Olmesartan was finalized. Diarrhea has not returned since. A colonoscopy performed six weeks after discharge was normal. Knowledge of the bowel olmesartan is recent and based almost solely on the description of 22 cases observed at the Mayo Clinic with patients, as in our case, have similar symptoms and lesions. We stress, about a publication of an isolated case, the possibility of less severe cases with histological abnormalities without clinical translation.

The Effect of Resting Heart Rate on the New Onset of Microalbuminuria in Patients With Type 2 Diabetes: A Subanalysis of the ROADMAP Study

The association between resting heart rate and new-onset microalbuminuria in patients with type 2 diabetes is not clear. The objective of the current analysis was to assess the relationship between heart rate and incidence of microalbuminuria in patients with type 2 diabetes. Data from the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study were retrospectively analyzed. New-onset microalbuminuria was documented and related to heart rate as recorded at baseline and last assessment, and the mean of the measurements taken during the double-blind part of the ROADMAP trial. Patients (n = 4299) had a mean age of 57.8 ± 8.7 years and 46.3% were male. Characteristics were not different between the olmesartan and the placebo groups, except for a higher systolic blood pressure (136.7 vs 135.7 mm Hg; P = 0.04) and albumin creatinine ratio (5.9 vs 5.5; P = 0.03). Increased risk of microalbuminuria was found with increasing heart rate, independent of whether baseline [highest vs lowest quartile odds ratio (OR) 1.39; 95% confidence interval (95% CI) 1.03-1.87; P = 0.032], last assessment (OR 1.71; 95% CI 1.26-2.31; P = 0.001), or mean heart rate was considered (OR: 1.77; 95% CI: 1.30-2.41; P = 0.0003). The greater risk of new-onset microalbuminuria with a high baseline heart rate was also found when data were adjusted for mean systolic blood pressure (OR: 1.35; 95% CI: 1.00-1.82; P = 0.0496; interaction P < 0.0001). Although there was no risk increase with baseline heart rate in the placebo group (P = 0.8253 for trend), microalbuminuria was less frequent in patients receiving olmesartan in the low heart rate quartiles (P = 0.002 for trend). A low heart rate reduces the risk of patients with type 2 diabetes developing microalbuminuria, independent of blood pressure. The data demonstrate potential benefits of reducing the heart rate of type 2 diabetes patients, and indicate that olmesartan could, in particular, reduce the risk of microalbuminuria in patients with low heart rate.

Prevention of electrocardiographic left ventricular remodeling by the angiotensin receptor blocker olmesartan in patients with type 2 diabetes

OBJECTIVE

To assess the ability of olmesartan (OLM) to prevent or delay left ventricular remodeling and hypertrophy in patients with type 2 diabetes.

METHODS

This prespecified ECG substudy of Randomised OlmesArtan and Diabetes MicroAlbuminuria Prevention (ROADMAP), which compared OLM with placebo, assessed the signs of left ventricular remodeling in patients with a 12-lead ECG at baseline and after at least 2 years. Cornell voltage QRS duration product (primary objective), Cornell voltage index and Sokolow-Lyon index were assessed.

RESULTS

In total, 9418 ECG recordings and 1513 patients from ROADMAP were analyzed (placebo, n = 736; OLM, n = 777). Quartiles defined by baseline Cornell voltage QRS duration product were assessed and the proportion of patients in the highest quartile (≥200 mVms) increased from 24.0 to 26.5% in the placebo group and decreased from 25.5 to 22.3% in the OLM group [odds ratio (OR) 0.598 (95% confidence interval [CI] 0.440-0.813); P = 0.0011]. The OR did not change after adjustment for baseline parameters. By the end of study, 38.7% of patients in the placebo group and 34.7% in the OLM group shifted from a lower to a higher quartile or remained in the highest quartile of Cornell voltage QRS duration product [OR 0.797 (95% CI 0.637-0.996); P = 0.0465]. This translated into a 20.3% risk reduction with OLM and suggested OLM attenuated the progression of left ventricular remodeling versus placebo.

CONCLUSION

OLM substantially delayed the development of left ventricular remodeling in type 2 diabetes. This effect was not explained by the differences in blood pressure control. Thus, OLM delayed the onset of microalbuminuria, as well as the ECG signs of cardiac structural adaptation in type 2 diabetes.

[Enteropathy due to olmesartan]

The olmesartan is a selective antagonist of angiotensin II indicated for the treatment of essential hypertension. We report the case of a gastrointestinal involvement with duodenal villous atrophy and lymphocytic infiltrate duodenal epithelial and colonic secondary to the olmesartan taking with test of positive reintroduction. The patient had chronic diarrhea with weight loss of 10kg occurred 1 month after the passage of 20 to 40mg/day olmesartan took 3 years. A rectosigmoidoscopy highlighted some puncture slightly erythematous areas. The responsibility of olmesartan was suspected and the drug was stopped. The evolution was rapidly favorable with disappearance of diarrhea 4 8hours later. Two days after the patient took the drug on its own initiative. Sigmoid biopsies showed an inflammatory infiltrate rich in lymphocytes. Gastroscopy showed erosive esophagitis and duodenal biopsies showed chronic duodenitis with epithelial lymphocytosis and subtotal villous atrophy. The reintroduction has led to the immediate resumption of diarrhea. olmetec was finalized. Diarrhea has not returned since. A colonoscopy performed 6 weeks after discharge was normal. Knowledge of the bowel olmesartan is recent and based almost solely on the description of 22 cases observed at the Mayo Clinic with patients, as in our case, have similar symptoms and lesions. We stress about a publication an isolated case the possibility of less severe cases with histological abnormalities without clinical translation.

Olmesartan protects endothelial cells against oxidative stress-mediated cellular injury

BACKGROUND

The primary cause of death of hemodialysis (HD) patients is cardiovascular disease, and increased oxidative stress has been proposed to be involved in the disease pathogenesis. In this study, we examined the effect of olmesartan on oxidative stress induced by angiotensin II, lipopolysaccharide, indoxyl sulfate, advanced oxidation protein products (AOPP) or hydrogen peroxide (H2O2), which are known to be present at higher concentrations in the blood of HD patients, using human umbilical vein endothelial cells (HUVECs).

METHODS

Oxidative stress was evaluated by measuring the mean fluorescence intensity of CM-H2DCFCA, an ROS-sensitive fluorescent dye, in HUVECs. HUVECs were incubated with each of the above compounds in the presence or absence of olmesartan. Moreover, these oxidant-stimulated cells were also treated with the reactive oxygen species (ROS) inhibitor N-acetyl-cysteine (NAC), NADPH oxidase inhibitor diphenylene iodonium (DPI) or PKC inhibitor calphostin C. In addition, we investigated the effects of olmesartan on cytotoxicity and vascular endothelial growth factor (VEGF) secretion, which is involved in vascular inflammation in HUVECs induced by AOPP or H2O2.

RESULTS

The treatment of these oxidant-stimulated cells with olmesartan resulted in a significant reduction in intracellular ROS production to an extent that was nearly equivalent to that of NAC, DPI or calphostin C. Furthermore, olmesartan reduced the cytotoxicity and VEGF secretion induced by AOPP or H2O2.

CONCLUSIONS

These results demonstrated that the antioxidant activity of olmesartan might contribute to both its vasculoprotective and anti-hypertensive effects.

Blood pressure control for diabetic retinopathy

BACKGROUND

Diabetic retinopathy is a common complication of diabetes and a leading cause of visual impairment and blindness. Research has established the importance of blood glucose control to prevent development and progression of the ocular complications of diabetes. Simultaneous blood pressure control has been advocated for the same purpose, but findings reported from individual studies have supported varying conclusions regarding the ocular benefit of interventions on blood pressure.

OBJECTIVES

The primary aim of this review was to summarize the existing evidence regarding the effect of interventions to control or reduce blood pressure levels among diabetics on incidence and progression of diabetic retinopathy, preservation of visual acuity, adverse events, quality of life, and costs. A secondary aim was to compare classes of anti-hypertensive medications with respect to the same outcomes.

SEARCH METHODS

We searched a number of electronic databases including CENTRAL as well as ongoing trial registries. We last searched the electronic databases on 25 April 2014. We also reviewed reference lists of review articles and trial reports selected for inclusion. In addition, we contacted investigators of trials with potentially pertinent data.

SELECTION CRITERIA

We included in this review randomized controlled trials (RCTs) in which either type 1 or type 2 diabetic participants, with or without hypertension, were assigned randomly to intense versus less intense blood pressure control, to blood pressure control versus usual care or no intervention on blood pressure, or to different classes of anti-hypertensive agents versus placebo.

DATA COLLECTION AND ANALYSIS

Pairs of review authors independently reviewed titles and abstracts from electronic and manual searches and the full text of any document that appeared to be relevant. We assessed included trials independently for risk of bias with respect to outcomes reported in this review. We extracted data regarding trial characteristics, incidence and progression of retinopathy, visual acuity, quality of life, and cost-effectiveness at annual intervals after study entry whenever provided in published reports and other documents available from included trials.

MAIN RESULTS

We included 15 RCTs, conducted primarily in North America and Europe, that had enrolled 4157 type 1 and 9512 type 2 diabetic participants, ranging from 16 to 2130 participants in individual trials. In 10 of the 15 RCTs, one group of participants was assigned to one or more anti-hypertensive agents and the control group received placebo. In three trials, intense blood pressure control was compared to less intense blood pressure control. In the remaining two trials, blood pressure control was compared with usual care. Five of the 15 trials enrolled type 1 diabetics, and 10 trials enrolled type 2 diabetics. Six trials were sponsored entirely by pharmaceutical companies, seven trials received partial support from pharmaceutical companies, and two studies received support from government-sponsored grants and institutional support.Study designs, populations, interventions, and lengths of follow-up (range one to nine years) varied among the included trials. Overall, the quality of the evidence for individual outcomes was low to moderate. For the primary outcomes, incidence and progression of retinopathy, the quality of evidence was downgraded due to inconsistency and imprecision of estimates from individual studies and differing characteristics of participants.For primary outcomes among type 1 diabetics, one of the five trials reported incidence of retinopathy and one trial reported progression of retinopathy after 4 to 5 years of treatment and follow-up; four of the five trials reported a combined outcome of incidence and progression over the same time interval. Among type 2 diabetics, 5 of the 10 trials reported incidence of diabetic retinopathy and 3 trials reported progression of retinopathy; one of the 10 trials reported a combined outcome of incidence and progression during a 4- to 5-year follow-up period. One trial in which type 2 diabetics participated had reported no primary (or secondary) outcome targeted for this review.The evidence from these trials supported a benefit of more intensive blood pressure control intervention with respect to 4- to 5-year incidence of diabetic retinopathy (estimated risk ratio (RR) 0.80; 95% confidence interval (CI) 0.71 to 0.92) and the combined outcome of incidence and progression (estimated RR 0.78; 95% CI 0.63 to 0.97). The available evidence provided less support for a benefit with respect to 4- to 5-year progression of diabetic retinopathy (point estimate was closer to 1 than point estimates for incidence and combined incidence and progression, and the CI overlapped 1; estimated RR 0.88; 95% CI 0.73 to 1.05). The available evidence regarding progression to proliferative diabetic retinopathy or clinically significant macular edema or moderate to severe loss of best-corrected visual acuity did not support a benefit of intervention on blood pressure: estimated RRs and 95% CIs 0.95 (0.83 to 1.09) and 1.06 (0.85 to 1.33), respectively, after 4 to 5 years of follow-up. Findings within subgroups of trial participants (type 1 and type 2 diabetics; participants with normal blood pressure levels at baseline and those with elevated levels) were similar to overall findings.The adverse event reported most often (7 of 15 trials) was death, yielding an estimated RR 0.86 (95% CI 0.64 to 1.14). Hypotension was reported from three trials; the estimated RR was 2.08 (95% CI 1.68 to 2.57). Other adverse ocular events were reported from single trials.

AUTHORS' CONCLUSIONS

Hypertension is a well-known risk factor for several chronic conditions in which lowering blood pressure has proven to be beneficial. The available evidence supports a beneficial effect of intervention to reduce blood pressure with respect to preventing diabetic retinopathy for up to 4 to 5 years. However, the lack of evidence to support such intervention to slow progression of diabetic retinopathy or to prevent other outcomes considered in this review, along with the relatively modest support for the beneficial effect on incidence, weakens the conclusion regarding an overall benefit of intervening on blood pressure solely to prevent diabetic retinopathy.

The Randomized Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) observational follow-up study: benefits of RAS blockade with olmesartan treatment are sustained after study discontinuation

Background

The Randomized Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study showed that 40 mg Olmesartan medoxomil (OM) versus placebo delayed microalbuminuria onset in patients with type 2 diabetes and normoalbuminuria.

Methods and Results

One thousand seven hundred and fifty‐eight ROADMAP patients (placebo arm: 877; OM arm: 881) participated in the observational follow up (OFU) with an average of 3.3 years. They received standard medical care and micro‐ and macrovascular events were documented. During observational follow‐up 62.9% and 60.1% in the former OM and placebo group, respectively, received treatment with a RAS blocking agent. During the OFU period the systolic blood pressure (SBP) increased to mean values of 135 mm Hg in both groups. Patients who had developed microalbuminuria during ROADMAP had a higher incidence of cardio‐ and cerebrovascular events (OR 1.77, CI 1.03 to 3.03, P=0.039) during the OFU period compared with patients in whom this was not the case. Diabetic retinopathy was significantly reduced in the former OM group (8 [0.9%] versus 23 [2.6%], OR: 0.34, CI 0.15 to 0.78, P=0.011) and the rate of microalbuminuria was numerically reduced. Congestive heart failure requiring hospitalization (3 [0.3%] versus 12 [1.4%], OR: 0.23, CI 0.06 to 0.85, P=0.027) was reduced and there was a trend of reduced cardio‐/cerebrovascular events (OM versus Pb: 73 [8.3%] versus 86 [9.8%] patients). Seven (0.8%) deaths (including 2 CV events) were reported in former placebo patients versus 3 (0.3%) (non‐CV events) in former OM patients.

Conclusions

Development of microalbuminuria is a valid marker for future CV events. RAS blockade with Olmesartan might cause sustained reduction (legacy effect) of micro‐ and macrovascular events.

Update on the ROADMAP clinical trial report: olmesartan for the prevention or delay of microalbuminuria development in type 2 diabetes

Albuminuria is associated with renal disease progression and cardiovascular disease development or cardiovascular complications in individuals at low, medium and high risk for these outcomes. Furthermore, in patients with vascular disease, changes in albuminuria independently predict mortality and cardiovascular and renal outcomes, and drug-induced lowering of albuminuria with the use of angiotensin-converting enzyme inhibitors and angiotensin receptor blockers confers long-term cardiovascular and renal protection. However, few studies have directly examined whether these agents might also prevent the development of albuminuria and whether this translates into protection from cardiovascular disease events. The ROADMAP trial was conducted in an attempt to give answers to these questions. The results provide evidence that pharmacological blockade of angiotensin II receptors is effective in reducing the risk of new-onset albuminuria in type 2 diabetic patients. The study was not able to determine if this will also lead to a long-term reduction of cardiovascular morbidity and mortality.

Reduction of Cardiovascular Risk through Angiotensin II Type 1 Receptor Antagonism : Focus on Olmesartan Medoxomil

It is well recognized that angiotensin II is involved in the pathogenesis of hypertension. Less well recognized - until recently, at least - is its involvement in the pathogenesis of atherosclerosis. However, it is now evident that angiotensin II promotes oxidative stress, vascular remodelling, inflammation, and the formation of atherosclerotic lesions. These actions, which are mediated almost exclusively by the angiotensin II type 1 (AT(1)) receptor, can be blocked by administration of angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]). Of the seven ARBs currently in clinical use, olmesartan is one of the most effective. The rapid and consistent antihypertensive efficacy of this drug, which allows a high proportion of patients to achieve their target blood pressure (BP), is associated with beneficial effects on oxidative stress, vascular remodelling, inflammation, and atherosclerotic lesion formation. These effects appear to be independent of the BP-lowering activity of olmesartan. In clinical trials, olmesartan has been shown to control microinflammation in hypertensive patients, to reduce oxidative stress in patients with type 2 diabetes mellitus, and to normalize the wall: lumen ratio of small resistance arteries (a measure of vascular remodelling) in patients with hypertension. Moreover, in a 2-year study involving hypertensive patients with carotid atherosclerosis (the MORE [Multicentre Olmesartan atherosclerosis Regression Evaluation] trial), olmesartan reduced the intima-media thickness of the carotid artery and significantly reduced the volume of large atherosclerotic plaques. These data suggest that olmesartan may reduce cardiovascular risk by simultaneously normalizing BP and reversing the proatherogenic effects of angiotensin II.

Antihypertensive agents for preventing diabetic kidney disease

BACKGROUND

Various blood pressure-lowering agents, and particularly inhibitors of the renin-angiotensin system (RAS), are widely used for people with diabetes to prevent the onset of diabetic kidney disease (DKD) and adverse cardiovascular outcomes. This is an update of a Cochrane review first published in 2003 and updated in 2005.

OBJECTIVES

This systematic review aimed to assess the benefits and harms of blood pressure lowering agents in people with diabetes mellitus and a normal amount of albumin in the urine (normoalbuminuria).

SEARCH METHODS

In January 2011 we searched the Cochrane Renal Group's Specialised Register through contact with the Trials Search Co-ordinator.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any antihypertensive agent with placebo or another agent in hypertensive or normotensive patients with diabetes and no kidney disease (albumin excretion rate < 30 mg/d) were included.

DATA COLLECTION AND ANALYSIS

Two investigators independently extracted data on kidney and other patient-relevant outcomes (all-cause mortality and serious cardiovascular events), and assessed study quality. Analysis was by a random effects model was applied to analyse results which were expressed as risk ratio (RR) and 95% confidence intervals (CI).

MAIN RESULTS

We identified 26 studies that enrolling 61,264 participants. Angiotensin-converting enzyme inhibitors (ACEi) reduced the risk of new onset of microalbuminuria, macroalbuminuria or both when compared to placebo (8 studies, 11,906 patients: RR 0.71, 95% CI 0.56 to 0.89), with similar benefits in people with and without hypertension (P = 0.74), and when compared to calcium channel blockers (5 studies, 1253 participants: RR 0.60, 95% CI 0.42 to 0.85). ACEi reduced the risk of death when compared to placebo (6 studies, 11,350 participants: RR 0.84, 95% CI 0.73 to 0.97). No effect was observed for angiotensin receptor blockers (ARB) when compared to placebo for new microalbuminuria, macroalbuminuria or both (5 studies, 7653 participants: RR 0.90, 95% CI 0.68 to 1.19) or death (5 studies, 7653 participants: RR 1.12, 95% CI 0.88 to 1.41); however, meta-regression suggested possible benefits from ARB for preventing kidney disease in high risk patients. There was a trend towards benefit from use of combined ACEi and ARB for prevention of DKD compared with ACEi alone (2 studies, 4171 participants: RR 0.88, 95% CI 0.78 to 1.00).The risk of cough was significantly increased with ACEi when compared to placebo (6 studies, 11,791 patients: RR 1.84, 95% CI 1.24 to 2.72), however there was no significant difference in the risk of headache or hyperkalaemia. There was no significant difference in the risk of cough, headache or hyperkalaemia when ARB was to placebo. On average risk of bias was judged to be either low (27% to 69%) or unclear (i.e. no information available) (8% to 73%). Blinding of participants, incomplete outcome data and selective reporting were judged to be high in 23%, 31% and 31% of studies, respectively.

AUTHORS' CONCLUSIONS

ACEi were found to prevent new onset DKD and death in normoalbuminuric people with diabetes, and could therefore be used in this population. More data are needed to clarify the role of ARB and other drug classes in preventing DKD.

Prevention of microalbuminuria in patients with type 2 diabetes and hypertension

BACKGROUND

We have previously demonstrated in the Randomized Olmesartan and Diabetes Microalbuminuria Prevention study that the angiotensin receptor blocker (ARB) olmesartan delays the onset of microalbuminuria in patients with type 2 diabetes. Now, we investigated the effect in the subpopulation with hypertension.

METHODS

Overall, 4020 patients with type 2 diabetes and hypertension at baseline (defined by a SBP/DBP ≥130/80 mmHg or use of antihypertensive medication) received either 40 mg olmesartan once daily or placebo for a median of 3.2 years in a randomized, double-blind, multicenter, controlled trial. Additional antihypertensive drugs (except angiotensin-converting enzyme inhibitors or ARBs) were used as needed to lower blood pressure (BP) to less than 130/80 mmHg.

RESULTS

The average BP was 126.3/74.7 and 129.5/76.6 mmHg, respectively (P < 0.001). Olmesartan delayed the time to onset of microalbuminuria by 25% (hazard ratio = 0.75; 95% confidence interval = 0.61-0.92, P = 0.007). Patients with a baseline SBP above the median of 136.7 mmHg and a SBP reduction above the median of 17.45 mmHg had a lower incidence of microalbuminuria than patients with a SBP reduction of less than 17.45 (8.1 vs. 11.2%, P < 0.0001). Independent from the baseline BP and the degree of BP reduction a 15-39% increase in the time to onset of microalbuminuria was detectable by olmesartan treatment. Cardiovascular events were comparable and occurred in 93 (4.6%) patients taking olmesartan and 86 (4.4%) taking placebo.

CONCLUSION

Patients with a better BP reduction are less likely to develop microalbuminuria. Treatment with olmesartan delayed the onset of microalbuminuria independent of the baseline BP and the degree of BP reduction.

Early treatment with olmesartan prevents juxtamedullary glomerular podocyte injury and the onset of microalbuminuria in type 2 diabetic rats

BACKGROUND

Studies were performed to determine if early treatment with an angiotensin II (Ang II) receptor blocker (ARB), olmesartan, prevents the onset of microalbuminuria by attenuating glomerular podocyte injury in Otsuka Long-Evans Tokushima Fatty (OLETF) rats with type 2 diabetes mellitus.

METHODS

OLETF rats were treated with either a vehicle, olmesartan (10 mg/kg/day) or a combination of nonspecific vasodilators (hydralazine 15 mg/kg/day, hydrochlorothiazide 6 mg/kg/day, and reserpine 0.3 mg/kg/day; HHR) from the age of 7-25 weeks.

RESULTS

OLETF rats were hypertensive and had microalbuminuria from 9 weeks of age. At 15 weeks, OLETF rats had higher Ang II levels in the kidney, larger glomerular desmin-staining areas (an index of podocyte injury), and lower gene expression of nephrin in juxtamedullary glomeruli, than nondiabetic Long-Evans Tokushima Otsuka (LETO) rats. At 25 weeks, OLETF rats showed overt albuminuria, and higher levels of Ang II in the kidney and larger glomerular desmin-staining areas in superficial and juxtamedullary glomeruli compared to LETO rats. Reductions in mRNA levels of nephrin were also observed in superficial and juxtamedullary glomeruli. Although olmesartan did not affect glucose metabolism, it decreased blood pressure and prevented the renal changes in OLETF rats. HHR treatment also reduced blood pressure, but did not affect the renal parameters.

CONCLUSIONS

This study demonstrated that podocyte injury occurs in juxtamedullary glomeruli prior to superficial glomeruli in type 2 diabetic rats with microalbuminuria. Early treatment with an ARB may prevent the onset of albuminuria through its protective effects on juxtamedullary glomerular podocytes.

The goal of blood pressure control for prevention of early diabetic microvascular complications

Lowering blood pressure may confer a benefit to diabetic microvascular complications comparable with glycemic control. Hypertension is causally related to kidney outcomes and is a risk factor for the development of diabetic retinopathy. The prevalence of hypertension increases as kidney disease progresses, so that it coexists with diabetes in up to 80% of those with overt nephropathy. A significant number of patients have hypertension or rising blood pressures in earlier stages, or even before microvascular complications appear. Because microalbuminuria markedly increases the risk of overt nephropathy as well as of cardiovascular complications, primary prevention (i.e., preventing or delaying the onset of microalbuminuria) continues to be explored, predominantly through use of renin-angiotensin blockade. Available data reviewed suggest that primary prevention through blood pressure reduction is more likely to benefit select groups (those with hypertension, cardiovascular risks, or old age). This review discusses the relationship between hypertension, diabetes, and kidney disease, the rationale for primary prevention, and the data that led to that conclusion.

Prevention of microalbuminuria in patients with type 2 diabetes: what do we know?

Cardiovascular and chronic kidney disease are epidemic throughout industrialized societies. Diabetes leads to premature cardiovascular disease and is regarded by many as the most common etiological factor for chronic kidney disease. Because most studies of blood-pressure lowering agents in people with diabetes and hypertension have been conducted in individuals who already have some target organ damage, it is unclear whether earlier intervention could prevent or delay the onset of renal or systemic vascular disease. In early disease there is only a low possibility of observing cardiovascular or renal events; thus intervention trials in this population must rely on disease markers such as microalbuminuria. Accordingly, the authors review the evidence to support the use of microalbuminuria as a disease marker in diabetic patients based on its strong association with renal and cardiovascular events, and discuss recent trials that examine the impact of preventing or delaying the onset of microalbuminuria.

Effects of olmesartan medoxomil, an angiotensin II type 1 receptor antagonist, on plasma concentration of B-type natriuretic peptide, in hypertensive patients with type 2 diabetes mellitus: a preliminary, observational, open-label study

BACKGROUND AND OBJECTIVE

Angiotensin II type 1 (AT1) receptor antagonists (angiotensin receptor blockers [ARBs]) are widely used for the treatment of not only hypertension but also cardiac dysfunction. B-type natriuretic peptide (BNP) is secreted mainly by the cardiac ventricle and plays an important role in the regulation of blood pressure (BP) and body fluid. It has been established that the plasma level of BNP is increased in patients with chronic heart failure in proportion to the severity of cardiac dysfunction. Because cardiac dysfunction is closely associated with a high risk of mortality in patients with diabetes mellitus, early identification and prevention of cardiac dysfunction are important. The objective of this study was to determine the effects of olmesartan medoxomil, a novel ARB, on the plasma level of BNP in hypertensive patients with type 2 diabetes.

METHODS

This was a preliminary, prospective, observational, open-label study. Sixty-eight type 2 diabetic patients with hypertension (systolic BP [SBP]≥140 mmHg or diastolic BP [DBP]≥90 mmHg) received olmesartan medoxomil 10–20 mg/day for 24 weeks. Plasma levels of BNP, as well as several clinical parameters of glycaemic control and lipid metabolism, were compared before and after 24 weeks of treatment. Another group consisting of 22 age- and body mass index-matched subjects not treated with olmesartan medoxomil was observed for reference purposes.

RESULTS

In the olmesartan medoxomil group, mean±SD SBP decreased from 152.8±16.4 at baseline to 146.8±14.4 mmHg after 24 weeks' treatment (p<0.05); similarly, mean±SD DBP decreased from 85.6±10.5 to 81.3±11.6 mmHg (p<0.05). In 53 subjects in whom plasma levels of BNP could be measured both before and after treatment, mean±SD BNP decreased from 41.3±49.9 to 32.5±36.3 pg/mL (p<0.05). Change in plasma BNP level over the 24-week treatment period in the olmesartan medoxomil group was not correlated with change in SBP or DBP. Multiple regression analysis revealed that change in plasma BNP level was not correlated with baseline value of or change in any other parameters. No other parameters in the olmesartan medoxomil group, and no parameters in the non-olmesartan medoxomil reference group, showed significant changes.

CONCLUSION

The current preliminary study showed that olmesartan medoxomil treatment might decrease plasma BNP levels, independent of its BP-lowering effect, in hypertensive patients with type 2 diabetes.

Cardiovascular and Renal Links along the Cardiorenal Continuum

The cardiorenal syndrome includes the widely known relationship between kidney function and cardiovascular disease. A large number of patients have various degrees of heart and kidney dysfunction worldwide, both in developed and developing countries. Disorders affecting one of them mostly involve the other. Such interactions represent the pathogenesis for a clinical condition called cardiorenal syndrome. Renal and cardiovascular disease shares similar etiologic risk factors. The majority of vascular events are caused by accelerated atherosclerosis. Moreover, cardiovascular events rarely occur in patients without underlying disease; rather, they typically take place as the final stage of a pathophysiological process that results in progressive vascular damage, including vital organ damage, specifically the kidney and the heart if these factors are uncontrolled. Chronic kidney disease is a novel risk factor included at this stage that accelerates both vascular and cardiac damage.

Olmesartan for the delay or prevention of microalbuminuria in type 2 diabetes

BACKGROUND

Microalbuminuria is an early predictor of diabetic nephropathy and premature cardiovascular disease. We investigated whether treatment with an angiotensin-receptor blocker (ARB) would delay or prevent the occurrence of microalbuminuria in patients with type 2 diabetes and normoalbuminuria.

METHODS

In a randomized, double-blind, multicenter, controlled trial, we assigned 4447 patients with type 2 diabetes to receive olmesartan (at a dose of 40 mg once daily) or placebo for a median of 3.2 years. Additional antihypertensive drugs (except angiotensin-converting-enzyme inhibitors or ARBs) were used as needed to lower blood pressure to less than 130/80 mm Hg. The primary outcome was the time to the first onset of microalbuminuria. The times to the onset of renal and cardiovascular events were analyzed as secondary end points.

RESULTS

The target blood pressure (<130/80 mm Hg) was achieved in nearly 80% of the patients taking olmesartan and 71% taking placebo; blood pressure measured in the clinic was lower by 3.1/1.9 mm Hg in the olmesartan group than in the placebo group. Microalbuminuria developed in 8.2% of the patients in the olmesartan group (178 of 2160 patients who could be evaluated) and 9.8% in the placebo group (210 of 2139); the time to the onset of microalbuminuria was increased by 23% with olmesartan (hazard ratio for onset of microalbuminuria, 0.77; 95% confidence interval, 0.63 to 0.94; P=0.01). The serum creatinine level doubled in 1% of the patients in each group. Slightly fewer patients in the olmesartan group than in the placebo group had nonfatal cardiovascular events--81 of 2232 patients (3.6%) as compared with 91 of 2215 patients (4.1%) (P=0.37)--but a greater number had fatal cardiovascular events--15 patients (0.7%) as compared with 3 patients (0.1%) (P=0.01), a difference that was attributable in part to a higher rate of death from cardiovascular causes in the olmesartan group than in the placebo group among patients with preexisting coronary heart disease (11 of 564 patients [2.0%] vs. 1 of 540 [0.2%], P=0.02).

CONCLUSIONS

Olmesartan was associated with a delayed onset of microalbuminuria, even though blood-pressure control in both groups was excellent according to current standards. The higher rate of fatal cardiovascular events with olmesartan among patients with preexisting coronary heart disease is of concern. (Funded by Daiichi Sankyo; ClinicalTrials.gov number, NCT00185159.).

Chronic kidney disease and albuminuria in arterial hypertension

Chronic kidney disease is a major public health problem worldwide: it is estimated that in the general population, 1 person in 10 has some degree of renal damage. Adequate blood pressure control represents the mainstay of treatment, to delay deterioration of renal function and prevent cardiovascular complications. Current evidence supports a target blood pressure value of 130/80 mm Hg or less (ie, <125/75 mm Hg) when proteinuria exceeds 1 g/L. Angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers represent the treatment of choice, especially in the presence of proteinuria. More complete blockade of the renin-angiotensin-aldosterone system (RAAS) has been advocated, using a combination of multiple RAAS blocker drugs or supramaximal doses to maximize renal protection. Achieving recommended blood pressure target values usually requires the use of multiple antihypertensive drugs, including diuretics and calcium channel blockers.

Role of olmesartan in combination therapy in blood pressure control and vascular function

Angiotensin receptor blockers have emerged as a first-line therapy in the management of hypertension and hypertension-related comorbidities. Since national and international guidelines have stressed the need to control blood pressure to <140/90 mmHg in uncomplicated hypertension and <130/80 mmHg in those with associated comorbidities such as diabetes or chronic kidney disease, these goal blood pressures can only be achieved through combination therapy. Of several drugs that can be effectively combined to attain the recommended blood pressure goals, fixed-dose combinations of angiotensin receptor blockers and the calcium channel blocker amlodipine provide additive antihypertensive effects associated with a safe profile and increased adherence to therapy. In this article, we review the evidence regarding the beneficial effects of renin–angiotensin system blockade with olmesartan medoxomil and amlodipine in terms of blood pressure control and improvement of vascular function and target organ damage.

The RAAS in the pathogenesis and treatment of diabetic nephropathy

Angiotensin II and other components of the renin-angiotensin-aldosterone system (RAAS) have a central role in the pathogenesis and progression of diabetic renal disease. A study in patients with type 1 diabetes and overt nephropathy found that RAAS inhibition with angiotensin-converting-enzyme (ACE) inhibitors was associated with a reduced risk of progression to end-stage renal disease and mortality compared with non-RAAS-inhibiting drugs. Blood-pressure control was similar between groups and proteinuria reduction was responsible for a large part of the renoprotective and cardioprotective effect. ACE inhibitors can also prevent microalbuminuria in patients with type 2 diabetes who are hypertensive and normoalbuminuric; in addition, ACE inhibitors are cardioprotective even in the early stages of diabetic renal disease. Angiotensin-II-receptor blockers (ARBs) are renoprotective (but not cardioprotective) in patients with type 2 diabetes and overt nephropathy or microalbuminuria. Studies have evaluated the renoprotective effect of other RAAS inhibitors, such as aldosterone antagonists and renin inhibitors, administered either alone or in combination with ACE inhibitors or ARBs. An important task for the future will be identifying which combination of agents achieves the best renoprotection (and cardioprotection) at the lowest cost. Such findings will have major implications, particularly in settings where money and facilities are limited and in settings where renal replacement therapy is not available and the prevention of kidney failure is life saving.

Evidence for the efficacy of ARBs across the cardiovascular continuum

INTRODUCTION

Angiotensin II receptor blockers (ARBs) are antihypertensive agents with considerable evidence of efficacy and safety for the reduction of cardiovascular (CV) disease risk in numerous patient populations from one end of the CV continuum (i.e., primary prevention among patients with CV risk factors) to the other (i.e., secondary prevention in the post-MI setting). There are several agents within the ARB class, all of which have contributed to various degrees to this evidence base.

SCOPE

This review presents the design and main results of large, well designed studies examining the CV risk-reducing properties of ARBs. The authors searched major literature databases (Embase, Medline, PubMed) for randomized, controlled studies published between January, 1995 and October, 2009 that compared ARBs with placebo or active controls and reported major CV outcomes (e.g., myocardial infarction, stroke) and/or mortality as the primary study endpoint(s).

LIMITATIONS

Although many trials evaluating similar agents are presented, between-trial comparisons are inappropriate. The results of each study stand on their own merits and weaknesses, but do not provide any additional insight into the results of the other studies.

RESULTS

Agents in the ARB class have demonstrated efficacy in reducing CV events and/or mortality in a number of different patient populations, from primary prevention studies in patients with pre-specified risk factors (e.g., hypertension and left-ventricular hypertrophy in the LIFE study) to secondary prevention (i.e., post-MI patients in the VALIANT study). Some studies have also demonstrated the statistical equivalence of ARBs to ACE inhibitors in certain populations (e.g., among post-MI patients in VALIANT and among a broad population of patients with vascular disease or diabetes in the ONTARGET). There are several major studies currently underway that will provide further information on the risk-reducing properties of ARBs in additional populations (e.g., patients with impaired glucose tolerance in the NAVIGATOR study).

CONCLUSIONS

ARBs have demonstrated efficacy in reducing CV morbidity and mortality in a broad spectrum of CV disease states across the CV continuum. Ongoing research continues to provide additional evidence, with ongoing trials investigating their role in additional patient populations.

Effects of an olmesartan medoxomil based treatment algorithm on 24-hour blood pressure control in patients with hypertension and type 2 diabetes

OBJECTIVE

The BENIFICIARY (BENIcar safety and efFICacy evaluatIon: An open-label, single-ARm, titration study in patients with hypertension and tYpe 2 diabetes) study was conducted to evaluate the efficacy and safety of olmesartan medoxomil (OM) plus hydrochlorothiazide (HCTZ) in patients with hypertension and type 2 diabetes.

RESEARCH DESIGN AND METHODS

After a placebo run-in period, 192 patients received OM 20 mg/day for 3 weeks. If blood pressure (BP) remained > or =120/70 mm Hg, patients were up-titrated to OM 40 mg/day for 3 weeks and subsequently (in 3-week intervals) to OM/HCTZ 40/12.5 mg/day, then OM/HCTZ 40/25 mg/day as necessary. Blood pressure was evaluated by mean 24-hour ambulatory BP monitoring (ABPM). The primary efficacy endpoint was the change in mean 24-hour ambulatory systolic BP (SBP) from baseline to Week 12. Secondary endpoints included: change in ambulatory diastolic BP (DBP) from baseline to Week 12; changes in ambulatory SBP and DBP during daytime, nighttime, and the last 2, 4, and 6 hours of the dosing interval; and achievement of prespecified ambulatory BP targets. CLINICAL TRIALS REGISTRY NUMBER: NCT00403481.

RESULTS

Mean 24-hour ambulatory SBP and DBP decreased by 20.4 mm Hg and 11.1 mm Hg, respectively (both P < 0.0001 to baseline), and 61.6%, 47.1%, and 39.0% of patients reached the ambulatory BP targets of <130/80 mm Hg, <125/75 mm Hg, and <120/80 mm Hg, respectively. The study medication was well tolerated with few adverse events: 67/192 patients (34.9%) experienced a treatment-emergent adverse event (TEAE) while 15/192 (7.8%) experienced a drug-related TEAE.

CONCLUSIONS

In this open-label ABPM study, an OM +/- HCTZ based treatment regimen safely and significantly reduced BP in patients with hypertension and type 2 diabetes when assessed by 24-hour ABPM.

Pathogenesis and treatment of microalbuminuria in patients with diabetes: the road ahead

The incidence of type 2 diabetes is increasing in the United States, which is expected to result in an increased prevalence of microalbuminuria and higher cardiovascular risk. Microalbuminuria is an indication that a low-level inflammatory process is ongoing. In patients with hypertension, with or without diabetes, increasing urinary albumin excretion (UAE) is associated with elevated levels of inflammatory markers, endothelial dysfunction, and platelet activation. Microalbuminuria is associated with an increased incidence of cardiovascular disease (CVD) morbidity and mortality in patients with hypertension and in those with diabetes with or without hypertension. Antihypertensive agents that modulate the renin-angiotensin-aldosterone system (RAAS) can delay the onset and reduce progression of microalbuminuria and decrease CVD morbidity and mortality in patients with diabetes. Clinical trials provide a spectrum of results regarding the protective effects of RAAS-blocking agents. Consideration of baseline blood pressure (BP), UAE and CVD risk, and the extent of BP lowering with treatment is necessary when interpreting clinical trial results in patients with microalbuminuria. It remains to be determined whether targeting the underlying inflammatory process can retard or prevent microalbuminuria progression or whether treatment of microalbuminuria can prevent end-stage renal disease or death.

Impact of olmesartan on blood pressure, endothelial function, and cardiovascular outcomes

The vascular endothelium, the largest "organ" in the body, synthesizes and releases a wide spectrum of vasoactive substances into the circulation. Endothelial dysfunction links hypertension and other cardiovascular (CV) risk factors that promote the development of atherosclerotic plaque, CV disease, and fatal and nonfatal CV events. Blood pressure (BP) reduction is the most effective way to reduce CV risk in patients with hypertension, but it is unknown whether endothelial dysfunction is a cause or consequence of hypertension. Renin-angiotensin-aldosterone system blockers improve endothelial function and have favorable vascular, metabolic, cardiac, and renoprotective effects that are independent of BP reduction. Olmesartan effectively reduces BP and also has vasoprotective properties, including reductions in endothelial dysfunction and inflammation, prevention of microalbuminuria, and reversal of vascular remodeling. Large-scale, long-term studies are needed to confirm that olmesartan has vasoprotective effects that are independent of BP control and to determine whether these pleiotropic effects translate into improved CV disease outcomes.

Determinants of urinary albumin excretion within the normal range in patients with type 2 diabetes: the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study

AIMS/HYPOTHESIS

In contrast to microalbuminuric type 2 diabetic patients, the factors correlated with urinary albumin excretion are less well known in normoalbuminuric patients. This may be important because even within the normoalbuminuric range, higher rates of albuminuria are known to be associated with higher renal and cardiovascular risk.

METHODS

At the time of screening for the Randomised Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) Study, the urinary albumin/creatinine ratio (UACR) was 0.44 mg/mmol in 4,449 type 2 diabetic patients. The independent correlates of UACR were analysed.

RESULTS

Independent correlates of UACR during baseline were (in descending order): night-time systolic BP (r(s) = 0.19); HbA(1c) (r(s) = 0.18); mean 24 h systolic BP (r(s) = 0.16); fasting blood glucose (r(s) = 0.16); night-time diastolic BP (r(s) = 0.12); office systolic BP, sitting (r(s) = 0.11), standing (r(s) = 0.10); estimated GFR (r(s) = 0.10); heart rate, sitting (r(s) = 0.10); haemoglobin (r(s) = -0.10); triacylglycerol (r(s) = 0.09); and uric acid (r(s) = -0.08; all p <or= 0.001). Significantly higher albumin excretion rates were found for the following categorical variables: higher waist circumference (more marked in men); presence of the metabolic syndrome; smoking (difference more marked in males); female sex; antihypertensive treatment; use of amlodipine; insulin treatment; family history of diabetes; and family history of cardiovascular disease (more marked in women).

CONCLUSIONS/INTERPRETATION

Although observational correlations do not prove causality, in normoalbuminuric type 2 diabetic patients the albumin excretion rate is correlated with many factors that are potentially susceptible to intervention.

TRIAL REGISTRATION

ClinicalTrials.gov ID no.: NCT00185159

FUNDING

This study was sponsored by Daichii-Sankyo.

Management of hypertension with fixed dose combinations of candesartan cilexetil and hydrochlorothiazide: patient perspectives and clinical utility

Hypertension treatment and control is largely unsatisfactory when guideline-defined blood pressure goal achievement and maintenance are considered. Patient- and physician-related factors leading to non-adherence interfere in this respect with the efficacy, tolerability, and convenient use of pharmacological treatment options. Blockers of the renin-angiotensin system (RAS) are an important component of antihypertensive combination therapy. Thiazide-type diuretics are usually added to increase the blood pressure lowering efficacy. Fixed drug-drug combinations of both principles like candesartan/hydrochlorothiazide (HCTZ) are highly effective in lowering blood pressure while providing improved compliance, a good tolerability, and largely neutral metabolic profile. Comparative studies with losartan/HCTZ have consistently shown a higher clinical efficacy with the candesartan/HCTZ combination. Data on the reduction of cardiovascular endpoints with fixed dose combinations of antihypertensive drugs are however scarce, as are the data for candesartan/HCTZ. But many trials have tested candesartan versus a non-RAS blocking comparator based on a standard therapy including thiazide diuretics. The indications tested were heart failure and stroke and particular emphasis was put on elderly patients or those with diabetes. In patients with heart failure, for example, the fixed dose combination might be applied in patients in whom individual titration resulted in a dose of 32 mg candesartan and 25 mg HCTZ which can then be combined into one tablet to increase compliance with treatment. Also in patients with stroke the fixed dose combination might be used in patients in whom maintenance therapy with both components is considered. Taken together candesartan/HCTZ assist both physicians and patients in achieving long-term blood pressure goal achievement and maintenance.

Olmesartan for the treatment of arterial hypertension

Angiotensin-receptor blockers (ARBs) are an important class of agents used for the treatment of arterial hypertension. Olmesartan medoxomil, the seventh latest ARB approved by the US FDA, is an oral, once-daily, AT(1)-receptor selective ARB with high receptor affinity. Pharmacologically, it acts as a competitive and insurmountable Ang II antagonist with linear pharmacokinetics and without cytochrome P450 interaction. The drug is licensed for the treatment of arterial hypertension alone or in combination with other antihypertensive agents. Olmesartan has demonstrated its dose-dependent inhibitory effect on Ang I-induced blood pressure responses between 10 and 80 mg in Phase II studies. These results, confirmed in an international clinical trial programme covering over 3000 hypertensive patients in numerous studies, demonstrated rapid blood pressure-lowering effects within 1 week. A daily oral dose of 20 mg olmesartan is considered to be the optimal dose. In clinical trials and postmarketing studies, olmesartan has been shown to be safe and well tolerated with an adverse event profile similar to the placebo. Active comparative studies demonstrated either similar or superior efficacy of olmesartan compared with other ARBs, angiotensin-converting enzymes inhibitors, beta-blockers or calcium-channel blockers. Besides its antihypertensive efficacy, olmesartan was shown in clinical trials to reduce vascular microinflammation, decrease intrarenal vascular resistance, significantly reduce vascular remodeling of small resistance arteries and exert antiatherosclerotic effects by significantly reducing the volume of large atherosclerotic plaques.

Renal protective effect of RAAS blockade across the renal continuum, with a review of the efficacy and safety of valsartan

Abstract Objective: The purpose of this report is to review key data on the angiotensin receptor blocker (ARB) valsartan, along with data from several pivotal studies with other ARBs and angiotensin-converting enzyme (ACE) inhibitors, to highlight the beneficial class effects of renin-angiotensin-aldosterone system (RAAS) blockade throughout the renal continuum.

METHODS

The selection of articles was based on a search of PubMed for clinical trials published between 1997 (the year in which valsartan was approved for sale in the US) and 2009 that involved valsartan and reported effects on renal function, plus a select range of articles on other agents acting on the RAAS, including key guidance documents issued during this time.

SUMMARY

Valsartan has been studied extensively and is widely used for the management of hypertension. Data from clinical studies involving valsartan and other ARBs and ACE inhibitors provide evidence of an additional renal protective effect. This renal protection apparently arises from hemodynamic, endothelial, and anti-inflammatory actions.

LIMITATIONS

Given the extent of the available literature on this topic, this review included only a subset of available publications. This report may reflect inherent heterogeneity between patient populations from these studies and also incorporate the limitations of these individual publications. The inclusion of guidance documents from several organizations may have resulted in apparent minor conflicts in the approaches of the different groups.

Lessons in hypertension from new clinical trials

Three important principles have emerged from recent epidemiologic and clinical studies in hypertension. First, patients with hypertension most often have other cardiovascular risk factors such as obesity and diabetes. Second, hypertension remains grossly undertreated. Third, at blood pressure levels once considered "high-normal," early organ damage may already be taking place in patients with multiple risk factors that, without treatment, can eventually lead to cardiovascular morbidity and mortality. The concept of evaluating global or overall risk is gaining wide acceptance, and US treatment guidelines may soon reflect these findings and assist clinicians in identifying individuals who are most likely to benefit from therapy. Results from clinical trials suggest that among the various pharmacologic agents available to treat hypertension, blockers of the renin-angiotensin system are effective in type 2 diabetes and chronic kidney disease, conditions that often occur in conjunction with hypertension.