Progression of renal insufficiency in type 2 diabetes with and without microalbuminuria: results of the Heart Outcomes and Prevention Evaluation (HOPE) randomized study

Angiotensin-converting-enzyme inhibitors and angiotensin receptor blockers for preventing the progression of diabetic kidney disease

BACKGROUND

Guidelines suggest that adults with diabetes and kidney disease receive treatment with angiotensin-converting-enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB). This is an update of a Cochrane review published in 2006.

OBJECTIVES

We compared the efficacy and safety of ACEi and ARB therapy (either as monotherapy or in combination) on cardiovascular and kidney outcomes in adults with diabetes and kidney disease.

SEARCH METHODS

We searched the Cochrane Kidney and Transplants Register of Studies to 17 March 2024 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included studies evaluating ACEi or ARB alone or in combination, compared to each other, placebo or no treatment in people with diabetes and kidney disease.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risk of bias and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) or standardised mean difference (SMD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

One hundred and nine studies (28,341 randomised participants) were eligible for inclusion. Overall, the risk of bias was high. Compared to placebo or no treatment, ACEi may make little or no difference to all-cause death (24 studies, 7413 participants: RR 0.91, 95% CI 0.73 to 1.15; I2 = 23%; low certainty) and with similar withdrawals from treatment (7 studies, 5306 participants: RR 1.03, 95% CI 0.90 to 1.19; I2 = 0%; low certainty). ACEi may prevent kidney failure (8 studies, 6643 participants: RR 0.61, 95% CI 0.39 to 0.94; I2 = 0%; low certainty). Compared to placebo or no treatment, ARB may make little or no difference to all-cause death (11 studies, 4260 participants: RR 0.99, 95% CI 0.85 to 1.16; I2 = 0%; low certainty). ARB have uncertain effects on withdrawal from treatment (3 studies, 721 participants: RR 0.85, 95% CI 0.58 to 1.26; I2 = 2%; low certainty) and cardiovascular death (6 studies, 878 participants: RR 3.36, 95% CI 0.93 to 12.07; low certainty). ARB may prevent kidney failure (3 studies, 3227 participants: RR 0.82, 95% CI 0.72 to 0.94; I2 = 0%; low certainty), doubling of serum creatinine (SCr) (4 studies, 3280 participants: RR 0.84, 95% CI 0.72 to 0.97; I2 = 32%; low certainty), and the progression from microalbuminuria to macroalbuminuria (5 studies, 815 participants: RR 0.44, 95% CI 0.23 to 0.85; I2 = 74%; low certainty). Compared to ACEi, ARB had uncertain effects on all-cause death (15 studies, 1739 participants: RR 1.13, 95% CI 0.68 to 1.88; I2 = 0%; low certainty), withdrawal from treatment (6 studies, 612 participants: RR 0.91, 95% CI 0.65 to 1.28; I2 = 0%; low certainty), cardiovascular death (13 studies, 1606 participants: RR 1.15, 95% CI 0.45 to 2.98; I2 = 0%; low certainty), kidney failure (3 studies, 837 participants: RR 0.56, 95% CI 0.29 to 1.07; I2 = 0%; low certainty), and doubling of SCr (2 studies, 767 participants: RR 0.88, 95% CI 0.52 to 1.48; I2 = 0%; low certainty). Compared to ACEi plus ARB, ACEi alone has uncertain effects on all-cause death (6 studies, 1166 participants: RR 1.08, 95% CI 0.49 to 2.40; I2 = 20%; low certainty), withdrawal from treatment (2 studies, 172 participants: RR 0.78, 95% CI 0.33 to 1.86; I2 = 0%; low certainty), cardiovascular death (4 studies, 994 participants: RR 3.02, 95% CI 0.61 to 14.85; low certainty), kidney failure (3 studies, 880 participants: RR 1.36, 95% CI 0.79 to 2.32; I2 = 0%; low certainty), and doubling of SCr (2 studies, 813 participants: RR 1.14, 95% CI 0.70 to 1.85; I2 = 0%; low certainty). Compared to ACEi plus ARB, ARB alone has uncertain effects on all-cause death (7 studies, 2607 participants: RR 1.02, 95% CI 0.76 to 1.37; I2 = 0%; low certainty), withdrawn from treatment (3 studies, 1615 participants: RR 0.81, 95% CI 0.53 to 1.24; I2 = 0%; low certainty), cardiovascular death (4 studies, 992 participants: RR 3.03, 95% CI 0.62 to 14.93; low certainty), kidney failure (4 studies, 2321 participants: RR 1.15, 95% CI 0.67 to 1.95; I2 = 29%; low certainty), and doubling of SCr (3 studies, 2252 participants: RR 1.18, 95% CI 0.85 to 1.64; I2 = 0%; low certainty). Comparative effects of different ACEi or ARB and low-dose versus high-dose ARB were rarely evaluated. No study compared different doses of ACEi. Adverse events of ACEi and ARB were rarely reported.

AUTHORS' CONCLUSIONS

ACEi or ARB may make little or no difference to all-cause and cardiovascular death compared to placebo or no treatment in people with diabetes and kidney disease but may prevent kidney failure. ARB may prevent the doubling of SCr and the progression from microalbuminuria to macroalbuminuria compared with a placebo or no treatment. Despite the international guidelines suggesting not combining ACEi and ARB treatment, the effects of ACEi or ARB monotherapy compared to dual therapy have not been adequately assessed. The limited data availability and the low quality of the included studies prevented the assessment of the benefits and harms of ACEi or ARB in people with diabetes and kidney disease. Low and very low certainty evidence indicates that it is possible that further studies might provide different results.

Antioxidants for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD) and death. Increased oxidative stress in people with CKD has been implicated as a potential causative factor. Antioxidant therapy decreases oxidative stress and may consequently reduce cardiovascular morbidity and death in people with CKD. This is an update of a Cochrane review first published in 2012.

OBJECTIVES

To examine the benefits and harms of antioxidant therapy on death and cardiovascular and kidney endpoints in adults with CKD stages 3 to 5, patients undergoing dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies until 15 November 2022 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials investigating the use of antioxidants, compared with placebo, usual or standard care, no treatment, or other antioxidants, for adults with CKD on cardiovascular and kidney endpoints.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened independently by two authors who also performed data extraction using standardised forms. Results were pooled using random effects models and expressed as risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 95 studies (10,468 randomised patients) that evaluated antioxidant therapy in adults with non-dialysis-dependent CKD (31 studies, 5342 patients), dialysis-dependent CKD (41 studies, 3444 patients) and kidney transplant recipients (21 studies, 1529 patients). Two studies enrolled dialysis and non-dialysis patients (153 patients). Twenty-one studies assessed the effects of vitamin antioxidants, and 74 assessed the effects of non-vitamin antioxidants. Overall, the quality of included studies was moderate to low or very low due to unclear or high risk of bias for randomisation, allocation concealment, blinding, and loss to follow-up. Compared with placebo, usual care, or no treatment, antioxidant therapy may have little or no effect on cardiovascular death (8 studies, 3813 patients: RR 0.94, 95% CI 0.64 to 1.40; I² = 33%; low certainty of evidence) and probably has little to no effect on death (any cause) (45 studies, 7530 patients: RR 0.95, 95% CI 0.82 to 1.11; I² = 0%; moderate certainty of evidence), CVD (16 studies, 4768 patients: RR 0.79, 95% CI 0.63 to 0.99; I² = 23%; moderate certainty of evidence), or loss of kidney transplant (graft loss) (11 studies, 1053 patients: RR 0.88, 95% CI 0.67 to 1.17; I² = 0%; moderate certainty of evidence). Compared with placebo, usual care, or no treatment, antioxidants had little to no effect on the slope of urinary albumin/creatinine ratio (change in UACR) (7 studies, 1286 patients: MD -0.04 mg/mmol, 95% CI -0.55 to 0.47; I² = 37%; very low certainty of evidence) but the evidence is very uncertain. Antioxidants probably reduced the progression to kidney failure (10 studies, 3201 patients: RR 0.65, 95% CI 0.41 to 1.02; I² = 41%; moderate certainty of evidence), may improve the slope of estimated glomerular filtration rate (change in eGFR) (28 studies, 4128 patients: MD 3.65 mL/min/1.73 m², 95% CI 2.81 to 4.50; I² = 99%; low certainty of evidence), but had uncertain effects on the slope of serum creatinine (change in SCr) (16 studies, 3180 patients: MD -13.35 µmol/L, 95% CI -23.49 to -3.23; I² = 98%; very low certainty of evidence). Possible safety concerns are an observed increase in the risk of infection (14 studies, 3697 patients: RR 1.30, 95% CI 1.14 to 1.50; I² = 3%; moderate certainty of evidence) and heart failure (6 studies, 3733 patients: RR 1.40, 95% CI 1.11 to 1.75; I² = 0; moderate certainty of evidence) among antioxidant users. Results of studies with a low risk of bias or longer follow-ups generally were comparable to the main analyses.

AUTHORS' CONCLUSIONS

We found no evidence that antioxidants reduced death or improved kidney transplant outcomes or proteinuria in patients with CKD. Antioxidants likely reduce cardiovascular events and progression to kidney failure and may improve kidney function. Possible concerns are an increased risk of infections and heart failure among antioxidant users. However, most studies were of suboptimal quality and had limited follow-up, and few included people undergoing dialysis or kidney transplant recipients. Furthermore, the large heterogeneity in interventions hampers drawing conclusions on the efficacy and safety of individual agents.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers for adults with early (stage 1 to 3) non-diabetic chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a long-term condition that occurs as a result of damage to the kidneys. Early recognition of CKD is becoming increasingly common due to widespread laboratory estimated glomerular filtration rate (eGFR) reporting, raised clinical awareness, and international adoption of the Kidney Disease Improving Global Outcomes (KDIGO) classifications. Early recognition and management of CKD affords the opportunity to prepare for progressive kidney impairment and impending kidney replacement therapy and for intervention to reduce the risk of progression and cardiovascular disease. Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are two classes of antihypertensive drugs that act on the renin-angiotensin-aldosterone system. Beneficial effects of ACEi and ARB on kidney outcomes and survival in people with a wide range of severity of kidney impairment have been reported; however, their effectiveness in the subgroup of people with early CKD (stage 1 to 3) is less certain. This is an update of a review that was last published in 2011.

OBJECTIVES

To evaluate the benefits and harms of ACEi and ARB or both in the management of people with early (stage 1 to 3) CKD who do not have diabetes mellitus (DM).

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 6 July 2023 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and Embase, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) reporting the effect of ACEi or ARB in people with early (stage 1 to 3) CKD who did not have DM were selected for inclusion. Only studies of at least four weeks duration were selected. Authors independently assessed the retrieved titles and abstracts and, where necessary, the full text to determine which satisfied the inclusion criteria.

DATA COLLECTION AND ANALYSIS

Data extraction was carried out by two authors independently, using a standard data extraction form. The methodological quality of included studies was assessed using the Cochrane risk of bias tool. Data entry was carried out by one author and cross-checked by another. When more than one study reported similar outcomes, data were pooled using the random-effects model. Heterogeneity was analysed using a Chi² test and the I² test. Results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes and mean difference (MD) and 95% CI for continuous outcomes. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach MAIN RESULTS: Six studies randomising 9379 participants with CKD stages 1 to 3 (without DM) met our inclusion criteria. Participants were adults with hypertension; 79% were male from China, Europe, Japan, and the USA. Treatment periods ranged from 12 weeks to three years. Overall, studies were judged to be at unclear or high risk of bias across all domains, and the quality of the evidence was poor, with GRADE rated as low or very low certainty. In low certainty evidence, ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo may make little or no difference to death (any cause) (2 studies, 8873 participants): RR 2.00, 95% CI 0.26 to 15.37; I² = 76%), total cardiovascular events (2 studies, 8873 participants): RR 0.97, 95% CI 0.90 to 1.05; I² = 0%), cardiovascular-related death (2 studies, 8873 participants): RR 1.73, 95% CI 0.26 to 11.66; I² = 54%), stroke (2 studies, 8873 participants): RR 0.76, 95% CI 0.56 to 1.03; I² = 0%), myocardial infarction (2 studies, 8873 participants): RR 1.00, 95% CI 0.84 to 1.20; I² = 0%), and adverse events (2 studies, 8873 participants): RR 1.33, 95% CI 1.26 to 1.41; I² = 0%). It is uncertain whether ACEi (benazepril 10 mg or trandolapril 2 mg) compared to placebo reduces congestive heart failure (1 study, 8290 participants): RR 0.75, 95% CI 0.59 to 0.95) or transient ischaemic attack (1 study, 583 participants): RR 0.94, 95% CI 0.06 to 15.01; I² = 0%) because the certainty of the evidence is very low. It is uncertain whether ARB (losartan 50 mg) compared to placebo (1 study, 226 participants) reduces: death (any-cause) (no events), adverse events (RR 19.34, 95% CI 1.14 to 328.30), eGFR rate of decline (MD 5.00 mL/min/1.73 m2, 95% CI 3.03 to 6.97), presence of proteinuria (MD -0.65 g/24 hours, 95% CI -0.78 to -0.52), systolic blood pressure (MD -0.80 mm Hg, 95% CI -3.89 to 2.29), or diastolic blood pressure (MD -1.10 mm Hg, 95% CI -3.29 to 1.09) because the certainty of the evidence is very low. It is uncertain whether ACEi (enalapril 20 mg, perindopril 2 mg or trandolapril 1 mg) compared to ARB (olmesartan 20 mg, losartan 25 mg or candesartan 4 mg) (1 study, 26 participants) reduces: proteinuria (MD -0.40, 95% CI -0.60 to -0.20), systolic blood pressure (MD -3.00 mm Hg, 95% CI -6.08 to 0.08) or diastolic blood pressure (MD -1.00 mm Hg, 95% CI -3.31 to 1.31) because the certainty of the evidence is very low.

AUTHORS' CONCLUSIONS

There is currently insufficient evidence to determine the effectiveness of ACEi or ARB in patients with stage 1 to 3 CKD who do not have DM. The available evidence is overall of very low certainty and high risk of bias. We have identified an area of large uncertainty for a group of patients who account for most of those diagnosed as having CKD.

Management of Blood Pressure in Patients With Chronic Kidney Disease Not Receiving Dialysis: Synopsis of the 2021 KDIGO Clinical Practice Guideline

DESCRIPTION

The Kidney Disease: Improving Global Outcomes (KDIGO) 2021 clinical practice guideline for the management of blood pressure (BP) in patients with chronic kidney disease (CKD) not receiving dialysis is an update of the KDIGO 2012 guideline on the same topic and reflects new evidence on the risks and benefits of BP-lowering therapy among patients with CKD. It is intended to support shared decision making by health care professionals working with patients with CKD worldwide. This article is a synopsis of the full guideline.

METHODS

The KDIGO leadership commissioned 2 co-chairs to convene an international Work Group of researchers and clinicians. After a Controversies Conference in September 2017, the Work Group defined the scope of the evidence review, which was undertaken by an evidence review team between October 2017 and April 2020. Evidence reviews were done according to the Cochrane Handbook. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach was used to guide the development of the recommendations and rate the strength and quality of the evidence. Practice points were included to provide guidance when evidence was insufficient to make a graded recommendation. The guideline was revised after public consultation between January and March 2020.

RECOMMENDATIONS

The updated guideline comprises 11 recommendations and 20 practice points. This synopsis summarizes key recommendations pertinent to the diagnosis and management of high BP in adults with CKD, excluding those receiving kidney replacement therapy. In particular, the synopsis focuses on recommendations for standardized BP measurement and a target systolic BP of less than 120 mm Hg, because these recommendations differ from some other guidelines.

Pharmacological interventions for heart failure in people with chronic kidney disease

BACKGROUND

Approximately half of people with heart failure have chronic kidney disease (CKD). Pharmacological interventions for heart failure in people with CKD have the potential to reduce death (any cause) or hospitalisations for decompensated heart failure. However, these interventions are of uncertain benefit and may increase the risk of harm, such as hypotension and electrolyte abnormalities, in those with CKD.

OBJECTIVES

This review aims to look at the benefits and harms of pharmacological interventions for HF (i.e., antihypertensive agents, inotropes, and agents that may improve the heart performance indirectly) in people with HF and CKD.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies through 12 September 2019 in consultation with an Information Specialist and using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We included randomised controlled trials of any pharmacological intervention for acute or chronic heart failure, among people of any age with chronic kidney disease of at least three months duration.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the records to identify eligible studies and extracted data on the following dichotomous outcomes: death, hospitalisations, worsening heart failure, worsening kidney function, hyperkalaemia, and hypotension. We used random effects meta-analysis to estimate treatment effects, which we expressed as a risk ratio (RR) with 95% confidence intervals (CI). We assessed the risk of bias using the Cochrane tool. We applied the GRADE methodology to rate the certainty of evidence.

MAIN RESULTS

One hundred and twelve studies met our selection criteria: 15 were studies of adults with CKD; 16 studies were conducted in the general population but provided subgroup data for people with CKD; and 81 studies included individuals with CKD, however, data for this subgroup were not provided. The risk of bias in all 112 studies was frequently high or unclear. Of the 31 studies (23,762 participants) with data on CKD patients, follow-up ranged from three months to five years, and study size ranged from 16 to 2916 participants. In total, 26 studies (19,612 participants) reported disaggregated and extractable data on at least one outcome of interest for our review and were included in our meta-analyses. In acute heart failure, the effects of adenosine A1-receptor antagonists, dopamine, nesiritide, or serelaxin on death, hospitalisations, worsening heart failure or kidney function, hyperkalaemia, hypotension or quality of life were uncertain due to sparse data or were not reported. In chronic heart failure, the effects of angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor blockers (ARB) (4 studies, 5003 participants: RR 0.85, 95% CI 0.70 to 1.02; I² = 78%; low certainty evidence), aldosterone antagonists (2 studies, 34 participants: RR 0.61 95% CI 0.06 to 6.59; very low certainty evidence), and vasopressin receptor antagonists (RR 1.26, 95% CI 0.55 to 2.89; 2 studies, 1840 participants; low certainty evidence) on death (any cause) were uncertain. Treatment with beta-blockers may reduce the risk of death (any cause) (4 studies, 3136 participants: RR 0.69, 95% CI 0.60 to 0.79; I² = 0%; moderate certainty evidence). Treatment with ACEi or ARB (2 studies, 1368 participants: RR 0.90, 95% CI 0.43 to 1.90; I² = 97%; very low certainty evidence) had uncertain effects on hospitalisation for heart failure, as treatment estimates were consistent with either benefit or harm. Treatment with beta-blockers may decrease hospitalisation for heart failure (3 studies, 2287 participants: RR 0.67, 95% CI 0.43 to 1.05; I² = 87%; low certainty evidence). Aldosterone antagonists may increase the risk of hyperkalaemia compared to placebo or no treatment (3 studies, 826 participants: RR 2.91, 95% CI 2.03 to 4.17; I² = 0%; low certainty evidence). Renin inhibitors had uncertain risks of hyperkalaemia (2 studies, 142 participants: RR 0.86, 95% CI 0.49 to 1.49; I² = 0%; very low certainty). We were unable to estimate whether treatment with sinus node inhibitors affects the risk of hyperkalaemia, as there were few studies and meta-analysis was not possible. Hyperkalaemia was not reported for the CKD subgroup in studies investigating other therapies. The effects of ACEi or ARB, or aldosterone antagonists on worsening heart failure or kidney function, hypotension, or quality of life were uncertain due to sparse data or were not reported. Effects of anti-arrhythmic agents, digoxin, phosphodiesterase inhibitors, renin inhibitors, sinus node inhibitors, vasodilators, and vasopressin receptor antagonists were very uncertain due to the paucity of studies.

AUTHORS' CONCLUSIONS

The effects of pharmacological interventions for heart failure in people with CKD are uncertain and there is insufficient evidence to inform clinical practice. Study data for treatment outcomes in patients with heart failure and CKD are sparse despite the potential impact of kidney impairment on the benefits and harms of treatment. Future research aimed at analysing existing data in general population HF studies to explore the effect in subgroups of patients with CKD, considering stage of disease, may yield valuable insights for the management of people with HF and CKD.

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.

Risk of incident chronic kidney disease is better reduced by bedtime than upon-awakening ingestion of hypertension medications

This trial investigated whether therapy with the entire daily dose of ≥1 hypertension medications at bedtime exerts a greater reduction in the risk of incident chronic kidney disease (CKD) than therapy with all medications upon awakening. We conducted a prospective, open-label, blinded endpoint trial of 2078 hypertensive patients without CKD (1017 men/1061 women, 53.6 ± 13.7 years of age) randomized to ingest all their prescribed hypertension medications upon awakening (n = 1041) or the entire daily dose of ≥1 of those medications at bedtime (n = 1037). During a 5.9-year median follow-up, 368 participants developed CKD. Patients of the bedtime, compared with the morning, treatment group showed (i) significantly lower asleep blood pressure (BP) mean, greater sleep-time relative BP decline, and attenuated prevalence of non-dipping at the final evaluation (38 vs. 55%; P < 0.001); and (ii) a significantly lower hazard ratio of CKD, adjusted for the significant influential characteristics of age, serum creatinine, urinary albumin, type 2 diabetes, previous cardiovascular event, asleep systolic BP mean, and sleep-time relative systolic BP decline (0.27 (95% confidence interval: 0.21-0.36); event-rate 8.3 vs. 27.1% in the bedtime and morning-treatment groups; P < 0.001). Greater benefit was observed for bedtime than awakening treatment, with angiotensin converting enzyme inhibitors and angiotensin receptor blockers. In hypertensive patients without CKD, ingestion of ≥1 BP-lowering medications at bedtime, mainly those modulating or blocking the effects of angiotensin II, compared with ingestion of all such medications upon-awakening, resulted in improved ambulatory BP control (significant further decrease of asleep BP and enhanced sleep-time relative BP decline) and reduced risk of incident CKD.

Resting heart rate is associated with renal disease outcomes in patients with vascular disease: results of the ONTARGET and TRANSCEND studies

BACKGROUND

Resting heart rate (RHR) is associated with cardiovascular disease outcomes in high-risk patients. It is not known whether RHR is predictive of renal outcomes such as albuminuria, end-stage renal disease (ESRD) or doubling of creatinine. We evaluated whether RHR could predict renal endpoints in patients at a high risk of cardiovascular disease. We also tested the effects of RHR at different levels of systolic blood pressure (SBP).

METHODS

We analysed data from 28 757 patients in the ONTARGET and TRANSCEND trials. RHR and SBP were available for a mean of 4.9 ± 0.4 visits (range 3-5) within the first 2 years of the studies. Albuminuria was determined at baseline, at 2 years and at study end.

RESULTS

Mean RHR was predictive of incident micro-albuminuria [hazard ratio (HR) for RHR ≥80 vs. <60 beats min(-1) 1.49, 95% confidence interval (CI) 1.29-1.71, P < 0.0001], incident macro-albuminuria (HR 1.84, 95% CI 1.39-2.42, P < 0.0001), doubling of creatinine (HR 1.47, 95% CI 1.00-2.17, P = 0.050) and ESRD (HR 1.78, 95% CI 1.00-3.16, P = 0.050), and the combined renal end-point (HR 1.51, 95% CI 1.32-1.74, P < 0.0001). Associations were robust at SBPs from <120 to ≥150 mmHg, with the lowest risk at a SBP of 130-140 mmHg.

CONCLUSION

Resting heart rate is a potent predictor of these renal outcomes, as well as their combination, in patients with cardiovascular disease. RHR at all SBP levels should be considered as a possible renal disease risk predictor and should be investigated as a treatment target with RHR-reducing agents.

ACE inhibitors and target organ protection

Lowering the risk of cardiovascular disease (CVD) involves more than treatment of individual risk factors such as hypertension, diabetes, and chronic kidney disease. In this article, Drs Toto, Rinner, and Ram present an evidence-based approach to reducing CVD risk and suggest that optimal treatment with angiotensin-converting enzyme (ACE) inhibitors should be extended to a larger proportion of at-risk patients and in particular to those not previously considered candidates for use of these agents.

Reduced tubular proteinuria in hypertensive rats treated with losartan is associated with higher renal cortical megalin expression

BACKGROUND

Several clinical studies have demonstrated that angiotensin II antagonists exert renoprotective effects beyond blood pressure control in hypertensive patients. The present work aimed to test the hypothesis that the antiproteinuric effects of losartan are associated with upregulation of the multi-ligand endocytic receptors megalin and cubilin in the proximal tubule of spontaneously hypertensive rats (SHR).

MATERIALS AND METHODS

Fourteen-week-old SHRs were orally treated for 7 weeks with losartan (50 mg/kg, SHR-L), hydralazine (30 mg/kg, SHR-H), or vehicle (SHR-V). Blood pressure and renal function were determined prior to and following drug treatment. Expression of renal cortical proteins was determined by immunoblotting.

RESULTS

Losartan and hydralazine reduced systolic blood pressure from pretreatment levels in SHRs to a similar extent. However, SHR-L displayed a much greater reduction in proteinuria than SHR-H (44±3% vs. 15±1%, p<0.01) relative to pretreatment urinary protein excretion levels. In SHRs treated with vehicle, proteinuria increased from 87±5 to 153±15 mg/(day kg BW). Reduced tubular proteinuria in SHRs treated with losartan was accompanied by a higher expression of megalin (125±28%) relative to either SHR-V or SHR-H. Neither losartan nor hydralazine significantly altered the renal cortical expression of cubilin in SHRs.

CONCLUSION

Collectively, our data demonstrate that the additional renoprotective effects of angiotensin II blockade by losartan are associated with upregulation of megalin in the renal proximal tubule of SHRs. Moreover, it strengthens the view that tubular dysfunction may represent an important contributing mechanism underlying proteinuria in hypertension.

Treatment strategies for the prevention of heart failure

With the astounding morbidity and mortality associated with heart failure (HF), preventive approaches have been explored. Controlling hypertension to prevent HF is well-established, especially with sodium restriction and thiazide-based antihypertensive therapies showing potential advantages. Control of dyslipidemia with aggressive statin therapy is particularly beneficial in preventing HF in the setting of acute coronary syndrome. The HOPE study also established the benefit of ACE inhibitors in the prevention of HF in high-risk subjects. Meanwhile old data supporting tight glycemic control in preventing HF have not been confirmed, suggesting the complexity of diabetic cardiomyopathy. Avoiding tobacco use and other known cardiotoxins are likely helpful. While there has been substantial development in identifying biomarkers predicting future development of HF, therapeutic interdiction guided by biomarker levels have yet to be established, even though it offers hope in modulating the natural history of the development of HF in at-risk individuals.

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.

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases

BACKGROUND

Our systematic review has demonstrated that antioxidant supplements may increase mortality. We have now updated this review.

OBJECTIVES

To assess the beneficial and harmful effects of antioxidant supplements for prevention of mortality in adults.

SEARCH METHODS

We searched The Cochrane Library, MEDLINE, EMBASE, LILACS, the Science Citation Index Expanded, and Conference Proceedings Citation Index-Science to February 2011. We scanned bibliographies of relevant publications and asked pharmaceutical companies for additional trials.

SELECTION CRITERIA

We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

Three authors extracted data. Random-effects and fixed-effect model meta-analyses were conducted. Risk of bias was considered in order to minimise the risk of systematic errors. Trial sequential analyses were conducted to minimise the risk of random errors. Random-effects model meta-regression analyses were performed to assess sources of intertrial heterogeneity.

MAIN RESULTS

Seventy-eight randomised trials with 296,707 participants were included. Fifty-six trials including 244,056 participants had low risk of bias. Twenty-six trials included 215,900 healthy participants. Fifty-two trials included 80,807 participants with various diseases in a stable phase. The mean age was 63 years (range 18 to 103 years). The mean proportion of women was 46%. Of the 78 trials, 46 used the parallel-group design, 30 the factorial design, and 2 the cross-over design. All antioxidants were administered orally, either alone or in combination with vitamins, minerals, or other interventions. The duration of supplementation varied from 28 days to 12 years (mean duration 3 years; median duration 2 years). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects model meta-analysis (21,484 dead/183,749 (11.7%) versus 11,479 dead/112,958 (10.2%); 78 trials, relative risk (RR) 1.02, 95% confidence interval (CI) 0.98 to 1.05) but significantly increased mortality in a fixed-effect model (RR 1.03, 95% CI 1.01 to 1.05). Heterogeneity was low with an I(2)- of 12%. In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. Meta-regression analysis did not find a significant difference in the estimated intervention effect in the primary prevention and the secondary prevention trials. In the 56 trials with a low risk of bias, the antioxidant supplements significantly increased mortality (18,833 dead/146,320 (12.9%) versus 10,320 dead/97,736 (10.6%); RR 1.04, 95% CI 1.01 to 1.07). This effect was confirmed by trial sequential analysis. Excluding factorial trials with potential confounding showed that 38 trials with low risk of bias demonstrated a significant increase in mortality (2822 dead/26,903 (10.5%) versus 2473 dead/26,052 (9.5%); RR 1.10, 95% CI 1.05 to 1.15). In trials with low risk of bias, beta-carotene (13,202 dead/96,003 (13.8%) versus 8556 dead/77,003 (11.1%); 26 trials, RR 1.05, 95% CI 1.01 to 1.09) and vitamin E (11,689 dead/97,523 (12.0%) versus 7561 dead/73,721 (10.3%); 46 trials, RR 1.03, 95% CI 1.00 to 1.05) significantly increased mortality, whereas vitamin A (3444 dead/24,596 (14.0%) versus 2249 dead/16,548 (13.6%); 12 trials, RR 1.07, 95% CI 0.97 to 1.18), vitamin C (3637 dead/36,659 (9.9%) versus 2717 dead/29,283 (9.3%); 29 trials, RR 1.02, 95% CI 0.98 to 1.07), and selenium (2670 dead/39,779 (6.7%) versus 1468 dead/22,961 (6.4%); 17 trials, RR 0.97, 95% CI 0.91 to 1.03) did not significantly affect mortality. In univariate meta-regression analysis, the dose of vitamin A was significantly associated with increased mortality (RR 1.0006, 95% CI 1.0002 to 1.001, P = 0.002).

AUTHORS' CONCLUSIONS

We found no evidence to support antioxidant supplements for primary or secondary prevention. Beta-carotene and vitamin E seem to increase mortality, and so may higher doses of vitamin A. Antioxidant supplements need to be considered as medicinal products and should undergo sufficient evaluation before marketing.

Renin-Angiotensin-aldosterone system in diabetes and hypertension

Activation of the renin-angiotensin-aldosterone system (RAAS) is the primary etiologic event in the development of hypertension in people with diabetes mellitus. Modulation of the RAAS has been shown to slow the progression and even cause regression of the microvascular and macrovascular complications associated with diabetes mellitus. Early pharmacotherapy with agents that decrease RAAS activation in the adipose tissue have had a dramatic impact on the prevalence of diabetes related complications. Recent data show that preventing the development of "angry fat" can prevent not just hypertension but also type 2 diabetes mellitus and its associated complications. This review updates what is known about angry fat and the role of RAAS inhibition in preventing the metabolic sequelae of local RAAS activation.

Changes in albuminuria predict mortality and morbidity in patients with vascular disease

The degree of albuminuria predicts cardiovascular and renal outcomes, but it is not known whether changes in albuminuria also predict similar outcomes. In two multicenter, multinational, prospective observational studies, a central laboratory measured albuminuria in 23,480 patients with vascular disease or high-risk diabetes. We quantified the association between a greater than or equal to twofold change in albuminuria in spot urine from baseline to 2 years and the incidence of cardiovascular and renal outcomes and all-cause mortality during the subsequent 32 months. A greater than or equal to twofold increase in albuminuria from baseline to 2 years, observed in 28%, associated with nearly 50% higher mortality (HR 1.48; 95% CI 1.32 to 1.66), and a greater than or equal to twofold decrease in albuminuria, observed in 21%, associated with 15% lower mortality (HR 0.85; 95% CI 0.74 to 0.98) compared with those with lesser changes in albuminuria, after adjustment for baseline albuminuria, BP, and other potential confounders. Increases in albuminuria also significantly associated with cardiovascular death, composite cardiovascular outcomes (cardiovascular death, myocardial infarction, stroke, and hospitalization for heart failure), and renal outcomes including dialysis or doubling of serum creatinine (adjusted HR 1.40; 95% CI 1.11 to 1.78). In conclusion, in patients with vascular disease, changes in albuminuria predict mortality and cardiovascular and renal outcomes, independent of baseline albuminuria. This suggests that monitoring albuminuria is a useful strategy to help predict cardiovascular risk.

Cardiovascular and renal outcomes with telmisartan, ramipril, or both in people at high renal risk: results from the ONTARGET and TRANSCEND studies

BACKGROUND

In the Ongoing Telmisartan Alone and in Combination With Ramipril Global End Point Trial (ONTARGET), dual therapy did not reduce cardiovascular or renal outcomes compared with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers alone. Previous controlled trials with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers have demonstrated greater cardiovascular and renal benefit in people with renal risk. We hypothesized that dual therapy would be more effective than monotherapy in patients with low glomerular filtration rate and elevated albuminuria.

METHODS AND RESULTS

Post hoc analysis was performed of renal subgroups of dual therapy versus monotherapy for the ONTARGET study and angiotensin receptor blocker versus placebo for the Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease (TRANSCEND). The studies featured hazard ratios by subgroups and Cox regression models with factors for treatment, subgroup, and interactions. The main cardiovascular outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure, and the main renal outcome was the composite of chronic dialysis or doubling of creatinine. In ONTARGET, there was no cardiovascular or renal benefit from dual over monotherapy in any subgroup, even with low glomerular filtration rate and/or elevated albuminuria. In TRANSCEND, in the comparison of angiotensin receptor blocker with placebo, there was a significant interaction for the main renal outcome (P = 0.01) in the direction of harm for patients with normoalbuminuria (0.37 versus 0.16 events per 100 patient-years; hazard ratio, 2.35; confidence interval, 1.33 to 4.15) but a trend to benefit with microalbuminuria (0.52 versus 0.89 events per 100 patient-years; hazard ratio, 0.60; confidence interval, 0.25 to 1.46) and macroalbuminuria (1.57 versus 2.60 events per 100 patient-years; hazard ratio, 0.71; confidence interval, 0.21 to 2.44).

CONCLUSIONS

This post hoc analysis does not support dual therapy over monotherapy in high-vascular risk patients with low glomerular filtration rate or albuminuria. This observation is a post hoc comparison and should be interpreted appropriately.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov Identifier: NCT00153101.

When to initiate ACEI/ARB therapy in patients with type 1 and 2 diabetes

Angiotensin converting enzyme inhibitors (ACEI) and angiotensin 2 receptor blockers (ARB) have become a mainstay of adjunctive therapy for the prevention and amelioration of diabetic nephropathy. Although ACEI were shown over 20 years ago to slow the rate of loss of renal function in diabetic subjects with decreased renal function, the question of how early in the course of diabetes to introduce them remains unresolved. Recent studies suggest that very early initiation of ACEI/ARB therapy may not have demonstrable beneficial effects even over a period of years.

Outcomes of antiproteinuric RAAS blockade: high-dose compared with dual therapy

Proteinuria is both a marker and a mediator of progressive renal damage; higher levels are associated with greater cardiovascular and renal risk. At normal and low levels of proteinuria (in the microalbuminuria range), the rate of hard renal events (dialysis and doubling of creatinine) is much lower than the mortality rate. At higher levels of proteinuria, the renal event rate surpasses the mortality rate. In the overt nephropathy range (proteinuria > 0.5 g/L), patients who achieve lower proteinuria with therapy have improved hard renal outcomes, but this result has not been demonstrated in the micro-albuminuria range. For patients with more severe overt nephropathy, there is a basic rationale for additional blockade of the renin-angiotensin-aldosterone system (RAAS). Dual blockade of this system and supramaximal dosing with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker (ARB) have been demonstrated to reduce proteinuria in these patients more than therapy using the maximum recommended doses of these agents. However, evidence that dual blockade provides additional benefits for hard renal and cardiovascular outcomes is lacking, and only one study shows a benefit for supramaximal dosing. Both treatment strategies increase the risk for complications such as hyperkalemia. Therapy for patients with nephropathy should include treatment with the maximum recommended doses of an ACE inhibitor or ARB in addition to lowering blood pressure to target. For patients with overt nephropathy, more research is required on the role of dual therapy or supramaximal dosing to reduce hard renal and cardiovascular outcomes. Practitioners using either of these strategies to manage proteinuria should monitor their patients carefully.

Integrating albuminuria and GFR in the assessment of diabetic nephropathy

The evaluation of diabetic nephropathy from research and clinical viewpoints depends on the assessment of two continuous variables, albumin excretion rate (AER) and glomerular filtration rate (GFR). These two parameters form the basis of both the European classification of five stages of diabetic nephropathy, assessed according to changes in AER and GFR (hyperfiltration, normoalbuminuria, microalbuminuria, macroalbuminuria and end-stage renal disease), and the National Kidney Foundation classification of five stages of chronic kidney disease based on categories of estimated GFR. Although increases in AER generally precede a decline in GFR, some patients follow a non-albuminuric pathway to renal impairment. In addition, studies indicate that GFR decreases in a linear fashion from normal or above-normal levels. Whether hyperfiltration is part of the pathogenetic process leading to diabetic nephropathy remains unclear. Ideally, both AER and GFR should be assessed at an early stage in patients being evaluated for diabetic nephropathy. New methods such as the use of cystatin-C-based equations for estimating GFR should be considered because current creatinine-based estimates are inaccurate at normal or high GFRs. Serial assessments of both AER and GFR might allow diabetic nephropathy to be diagnosed at early stages of the disease process that are selectively responsive to new interventions. The successful integration of AER categories with the recently defined stages of GFR represents a new challenge in the management of diabetic nephropathy.

Proteinuria as a surrogate outcome in CKD: report of a scientific workshop sponsored by the National Kidney Foundation and the US Food and Drug Administration

Changes in proteinuria have been suggested as a surrogate outcome for kidney disease progression to facilitate the conduct of clinical trials. This report summarizes a workshop sponsored by the National Kidney Foundation and US Food and Drug Administration (FDA) with the following goals: (1) to evaluate the strengths and limitations of criteria for assessment of proteinuria as a potential surrogate end point for clinical trials in chronic kidney disease (CKD), (2) to explore the strengths and limitations of available data for proteinuria as a potential surrogate end point, and (3) to delineate what more needs to be done to evaluate proteinuria as a potential surrogate end point. We review the importance of proteinuria in CKD, including the conceptual model for CKD, measurement of proteinuria and albuminuria, and epidemiological characteristics of albuminuria in the United States. We discuss surrogate end points in clinical trials of drug therapy, including criteria for drug approval, the definition of a surrogate end point, and criteria for evaluation of surrogacy based on biological plausibility, epidemiological characteristics, and clinical trials. Next, the report summarizes data for proteinuria as a potential surrogate outcome in 3 broad clinical areas: early diabetic kidney disease, nephrotic syndrome, and diseases with mild to moderate proteinuria. We conclude with a synthesis of data and recommendations for further research. At the present time, there appears to be sufficient evidence to recommend changes in proteinuria as a surrogate for kidney disease progression in only selected circumstances. Further research is needed to define additional contexts in which changes in proteinuria can be expected to predict treatment effect. We recommend collaboration among many groups, including academia, industry, the FDA, and the National Institutes of Health, to share data from past and future studies.

Renal outcomes with telmisartan, ramipril, or both, in people at high vascular risk (the ONTARGET study): a multicentre, randomised, double-blind, controlled trial

BACKGROUND

Angiotensin receptor blockers (ARB) and angiotensin converting enzyme (ACE) inhibitors are known to reduce proteinuria. Their combination might be more effective than either treatment alone, but long-term data for comparative changes in renal function are not available. We investigated the renal effects of ramipril (an ACE inhibitor), telmisartan (an ARB), and their combination in patients aged 55 years or older with established atherosclerotic vascular disease or with diabetes with end-organ damage.

METHODS

The trial ran from 2001 to 2007. After a 3-week run-in period, 25 620 participants were randomly assigned to ramipril 10 mg a day (n=8576), telmisartan 80 mg a day (n=8542), or to a combination of both drugs (n=8502; median follow-up was 56 months), and renal function and proteinuria were measured. The primary renal outcome was a composite of dialysis, doubling of serum creatinine, and death. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

784 patients permanently discontinued randomised therapy during the trial because of hypotensive symptoms (406 on combination therapy, 149 on ramipril, and 229 on telmisartan). The number of events for the composite primary outcome was similar for telmisartan (n=1147 [13.4%]) and ramipril (1150 [13.5%]; hazard ratio [HR] 1.00, 95% CI 0.92-1.09), but was increased with combination therapy (1233 [14.5%]; HR 1.09, 1.01-1.18, p=0.037). The secondary renal outcome, dialysis or doubling of serum creatinine, was similar with telmisartan (189 [2.21%]) and ramipril (174 [2.03%]; HR 1.09, 0.89-1.34) and more frequent with combination therapy (212 [2.49%]: HR 1.24, 1.01-1.51, p=0.038). Estimated glomerular filtration rate (eGFR) declined least with ramipril compared with telmisartan (-2.82 [SD 17.2] mL/min/1.73 m(2)vs -4.12 [17.4], p<0.0001) or combination therapy (-6.11 [17.9], p<0.0001). The increase in urinary albumin excretion was less with telmisartan (p=0.004) or with combination therapy (p=0.001) than with ramipril.

INTERPRETATION

In people at high vascular risk, telmisartan's effects on major renal outcomes are similar to ramipril. Although combination therapy reduces proteinuria to a greater extent than monotherapy, overall it worsens major renal outcomes.

Antioxidant supplements for preventing gastrointestinal cancers

BACKGROUND

Oxidative stress may cause gastrointestinal cancers. The evidence on whether antioxidant supplements are effective in preventing gastrointestinal cancers is contradictory.

OBJECTIVES

To assess the beneficial and harmful effects of antioxidant supplements in preventing gastrointestinal cancers.

SEARCH STRATEGY

We identified trials through the trials registers of the four Cochrane Review Groups on gastrointestinal diseases, The Cochrane Central Register of Controlled Trials in The Cochrane Library (Issue 2, 2007), MEDLINE, EMBASE, LILACS, SCI-EXPANDED, and The Chinese Biomedical Database from inception to October 2007. We scanned reference lists and contacted pharmaceutical companies.

SELECTION CRITERIA

Randomised trials comparing antioxidant supplements to placebo/no intervention examining occurrence of gastrointestinal cancers.

DATA COLLECTION AND ANALYSIS

Two authors (GB and DN) independently selected trials for inclusion and extracted data. Outcome measures were gastrointestinal cancers, overall mortality, and adverse effects. Outcomes were reported as relative risks (RR) with 95% confidence interval (CI) based on random-effects and fixed-effect model meta-analysis. Meta-regression assessed the effect of covariates across the trials.

MAIN RESULTS

We identified 20 randomised trials (211,818 participants), assessing beta-carotene (12 trials), vitamin A (4 trials), vitamin C (8 trials), vitamin E (10 trials), and selenium (9 trials). Trials quality was generally high. Heterogeneity was low to moderate. Antioxidant supplements were without significant effects on gastrointestinal cancers (RR 0.94, 95% CI 0.83 to 1.06). However, there was significant heterogeneity (I(2) = 54.0%, P = 0.003). The heterogeneity may have been explained by bias risk (low-bias risk trials RR 1.04, 95% CI 0.96 to 1.13 compared to high-bias risk trials RR 0.59, 95% CI 0.43 to 0.80; test of interaction P < 0.0005), and type of antioxidant supplement (beta-carotene potentially increasing and selenium potentially decreasing cancer risk). The antioxidant supplements had no significant effects on mortality in a random-effects model meta-analysis (RR 1.02, 95% CI 0.97 to 1.07, I(2) = 53.5%), but significantly increased mortality in a fixed-effect model meta-analysis (RR 1.04, 95% CI 1.02 to 1.07). Beta-carotene in combination with vitamin A (RR 1.16, 95% CI 1.09 to 1.23) and vitamin E (RR 1.06, 95% CI 1.02 to 1.11) significantly increased mortality. Increased yellowing of the skin and belching were non-serious adverse effects of beta-carotene. In five trials (four with high risk of bias), selenium seemed to show significant beneficial effect on gastrointestinal cancer occurrence (RR 0.59, 95% CI 0.46 to 0.75, I(2) = 0%).

AUTHORS' CONCLUSIONS

We could not find convincing evidence that antioxidant supplements prevent gastrointestinal cancers. On the contrary, antioxidant supplements seem to increase overall mortality. The potential cancer preventive effect of selenium should be tested in adequately conducted randomised trials.

Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases

BACKGROUND

Animal and physiological research as well as observational studies suggest that antioxidant supplements may improve survival.

OBJECTIVES

To assess the effect of antioxidant supplements on mortality in primary or secondary prevention randomised clinical trials.

SEARCH STRATEGY

We searched The Cochrane Library (Issue 3, 2005), MEDLINE (1966 to October 2005), EMBASE (1985 to October 2005), and the Science Citation Index Expanded (1945 to October 2005). We scanned bibliographies of relevant publications and wrote to pharmaceutical companies for additional trials.

SELECTION CRITERIA

We included all primary and secondary prevention randomised clinical trials on antioxidant supplements (beta-carotene, vitamin A, vitamin C, vitamin E, and selenium) versus placebo or no intervention. Included participants were either healthy (primary prevention trials) or had any disease (secondary prevention trials).

DATA COLLECTION AND ANALYSIS

Three authors extracted data. Trials with adequate randomisation, blinding, and follow-up were classified as having a low risk of bias. Random-effects and fixed-effect meta-analyses were performed. Random-effects meta-regression analyses were performed to assess sources of intertrial heterogeneity.

MAIN RESULTS

Sixty-seven randomised trials with 232,550 participants were included. Forty-seven trials including 180,938 participants had low risk of bias. Twenty-one trials included 164,439 healthy participants. Forty-six trials included 68111 participants with various diseases (gastrointestinal, cardiovascular, neurological, ocular, dermatological, rheumatoid, renal, endocrinological, or unspecified). Overall, the antioxidant supplements had no significant effect on mortality in a random-effects meta-analysis (relative risk [RR] 1.02, 95% confidence interval [CI] 0.99 to 1.06), but significantly increased mortality in a fixed-effect model (RR 1.04, 95% CI 1.02 to 1.06). In meta-regression analysis, the risk of bias and type of antioxidant supplement were the only significant predictors of intertrial heterogeneity. In the trials with a low risk of bias, the antioxidant supplements significantly increased mortality (RR 1.05, 95% CI 1.02 to 1.08). When the different antioxidants were assessed separately, analyses including trials with a low risk of bias and excluding selenium trials found significantly increased mortality by vitamin A (RR 1.16, 95% CI 1.10 to 1.24), beta-carotene (RR 1.07, 95% CI 1.02 to 1.11), and vitamin E (RR 1.04, 95% CI 1.01 to 1.07), but no significant detrimental effect of vitamin C (RR 1.06, 95% CI 0.94 to 1.20). Low-bias risk trials on selenium found no significant effect on mortality (RR 0.91, 95% CI 0.76 to 1.09).

AUTHORS' CONCLUSIONS

We found no evidence to support antioxidant supplements for primary or secondary prevention. Vitamin A, beta-carotene, and vitamin E may increase mortality. Future randomised trials could evaluate the potential effects of vitamin C and selenium for primary and secondary prevention. Such trials should be closely monitored for potential harmful effects. Antioxidant supplements need to be considered medicinal products and should undergo sufficient evaluation before marketing.

Treating elderly people with diabetes and stages 3 and 4 chronic kidney disease

Dedicated European and US clinical guidelines for type 2 diabetes in the elderly have been released, but they do not specifically address the issue of advanced chronic kidney disease (CKD) in older patients with diabetes. General clinical guidelines have been published on the treatment of patients with diabetic nephropathy (DN), but these address the issue of how to prevent progression and treat advanced DN without distinguishing between different age groups. Elderly patients with diabetes and stages 3 to 4 CKD have particular needs that differ from those of younger patients with the same conditions. This is mainly due to their frailty and shorter life expectancy. Differently tailored therapeutic strategies are needed, which may have less stringent targets; and the use of common drugs should be critically evaluated. The management agenda (metabolic control, low-protein diet, controlling BP, preventing progression of advanced DN, preventing cardiovascular outcomes) for these patients is discussed in light of the limits and perspectives of current guidelines. Intensive, simultaneous management of all items on the agenda may not be feasible for a proportion of older patients, and clinicians may have to give priority to reducing some risk factors rather than others, choosing between different therapies.

2-year effects of pioglitazone add-on to sulfonylurea or metformin on oral glucose tolerance in patients with type 2 diabetes

AIM

We report the effectiveness of the thiazolidinedione, pioglitazone, as add-on medication to metformin or sulfonylurea in reducing post-load serum glucose levels, as assessed by 3-h oral glucose tolerance testing (OGTT).

METHODS

Adult patients with Type 2 diabetes took part in one of two large-scale, 2-year clinical trials. One study compared pioglitazone treatment as add-on to failing metformin therapy (N=317) with add-on gliclazide treatment to metformin (N=313). The other study compared combination therapy with pioglitazone added to existing failing sulfonylurea therapy (N=319) with metformin treatment in addition to sulfonylurea (N=320). HbA(1c) and fasting plasma glucose concentrations were measured at baseline and throughout the study and at the final visit at week 104. At selected centers (N=299 patients), a 3-h OGTT was performed at baseline and at week 104.

RESULTS

At week 104, mean HbA(1c) reduction from baseline was 0.89% for pioglitazone and 0.77% for gliclazide addition to metformin (p=0.200) and 1.03% with pioglitazone and 1.16% with metformin addition to sulfonylurea (p=0.173) in the total patient cohort. In the 299 patients who underwent OGTT, 2 years of treatment with pioglitazone, whether added to existing metformin or sulfonylurea medication, resulted in decreases in glucose excursions after an oral glucose load without increasing post-load serum insulin concentrations. In contrast, gliclazide in combination with metformin therapy caused increases in both post-load serum glucose and insulin excursions after 2 years, whereas metformin add-on to sulfonylurea did not have a significant effect on post-load serum glucose concentrations and resulted in an increase in insulin levels.

CONCLUSIONS

There were no significant differences in HbA(1c) levels between groups. However, 2-year treatment with pioglitazone as an add-on to either failing metformin or sulfonylurea therapy improved post-load glucose excursions without affecting insulin secretion. In contrast, glucose excursions were not improved by gliclazide or metformin add-on therapy, despite increases in post-load insulin levels. These data suggest that pioglitazone reduces peripheral insulin resistance via mechanisms different from those of metformin.

European guidelines on cardiovascular disease prevention in clinical practice: executive summary. Fourth Joint Task Force of the European Society of Cardiology and other societies on cardiovascular disease prevention in clinical practice (constituted by representatives of nine societies and by invited experts)

Other experts who contributed to parts of the guidelines: Edmond Walma, Schoonhoven (The Netherlands), Tony Fitzgerald, Dublin (Ireland), Marie Therese Cooney, Dublin (Ireland), Alexandra Dudina, Dublin (Ireland) European Society of Cardiology (ESC) Committee for Practice Guidelines (CPG):, Alec Vahanian (Chairperson) (France), John Camm (UK), Raffaele De Caterina (Italy), Veronica Dean (France), Kenneth Dickstein (Norway), Christian Funck-Brentano (France), Gerasimos Filippatos (Greece), Irene Hellemans (The Netherlands), Steen Dalby Kristensen (Denmark), Keith McGregor (France), Udo Sechtem (Germany), Sigmund Silber (Germany), Michal Tendera (Poland), Petr Widimsky (Czech Republic), José Luis Zamorano (Spain)

Document reviewers: Irene Hellemans (CPG Review Coordinator) (The Netherlands), Attila Altiner (Germany), Enzo Bonora (Italy), Paul N. Durrington (UK), Robert Fagard (Belgium), Simona Giampaoli(Italy), Harry Hemingway (UK), Jan Hakansson (Sweden), Sverre Erik Kjeldsen (Norway), Mogens Lytken Larsen (Denmark), Giuseppe Mancia (Italy), Athanasios J. Manolis (Greece), Kristina Orth-Gomer (Sweden), Terje Pedersen (Norway), Mike Rayner (UK), Lars Ryden (Sweden), Mario Sammut (Malta), Neil Schneiderman (USA), Anton F. Stalenhoef (The Netherlands), Lale Tokgözoglu (Turkey), Olov Wiklund (Sweden), Antonis Zampelas (Greece)

Different Types of Renal Dysfunction in Patients with Acute Myocardial Infarction Treated with Percutaneous Coronary Intervention

BACKGROUND

The prognostic significance of different types of renal dysfunction in patients with acute myocardial infarction (AMI) treated with percutaneous coronary intervention (PCI) has not been well characterized.

METHODS

The single-center AMI registry encompassed 1,486 consecutive AMI patients treated with PCI, who were followed by mean 29.7 months. Subjects with an estimated glomerular filtration rate <60 mL/min per 1.73 m2 at baseline were selected (n = 283, 19.0%) and incorporated into the chronic kidney disease (CKD) group. The control group consisted of 1,203 subjects with normal renal function (81.0%). The CKD patients were divided into subgroups: with contrast-induced nephropathy - CKD + CIN (n = 68, 4.6%) and without - CKD-CIN (n = 215, 14.5%).

RESULTS

Remote mortality rate was significantly higher in CKD group (34.6%) and in particular subgroups: CKD + CIN (47.0%), CKD-CIN (31.0%) than in controls (9.1%, P < 0.001 for all study groups vs controls). Multivariate analysis identified CKD as an independent predictor of any-cause death in the whole population (hazard ratio [HR] 1.77, 95% confidence interval [CI] 1.60-1.94, P < 0.001). Similarly, CKD + CIN contrary to CKD-CIN had significant and independent influence on remote survival in study population (HR 2.16, 95% CI 1.95-2.37, P < 0.001).

CONCLUSIONS

CKD and its types have significant, negative influence on long-term survival in AMI patients treated with PCI. It is especially strongly expressed in those CKD patients who develop contrast-induced nephropathy, which occurrence is an independent risk factor of mortality associated with over twofold increase of death hazard.

Preventing microalbuminuria in patients with type 2 diabetes

The public health burden of type 2 diabetes mellitus has been dramatically increasing world-wide. The chronic complications of type 2 diabetes play an important role in decreasing life expectancy and adversely affecting quality of life. Diabetic nephropathy, which is originally microvascular in nature, is widely considered an important complication of diabetes. In prospective clinical investigations, increased urinary albumin excretion proved to be associated not only with subsequent renal outcomes but also with cardiovascular morbidity/mortality independently of other risk factors. Therefore, microalbuminuria as an early sign of increased urinary albumin excretion should be considered important for both treatment and even for prevention. Preventing microalbuminuria might diminish progression to overt nephropathy and, hopefully, might limit cardiovascular events. Regarding primary prevention of diabetic nephropathy, therapeutic intervention should optimally be initiated at the stage of normoalbuminuria. Although additional factors such as smoking cessation, reduction of protein intake, and treatment of lipid abnormalities are important, providing optimal diabetic control as well as targeting optimal blood pressure are the key elements of a prevention strategy in diabetic patients. Recently, the Bergamo Nephrologic Diabetes Complications Trial (BENEDICT) documented that a significant decrease of the development of persistent microalbuminuria could be achieved by using an ACE-inhibitor, trandolapril alone or in combination with verapamil SR, a non-dihydropyridine calcium-channel blocker in hypertensive type 2 diabetic patients with normoalbuminuria. The results of this primary-prevention strategy should be corroborated by further investigations to determine whether these beneficial changes could later result in improvement of renal clinical outcomes, macrovascular complications, or both.

Optimizing hypertension management in clinical practice

A clear relationship exists between elevated blood pressure (BP) and various manifestations of cardiovascular disease. Despite the availability of numerous treatment guidelines, hypertension remains inadequately controlled, with only a small proportion of patients achieving target BP levels. Many factors, both patient and physician related, contribute to this poor level of hypertension control. Major determinants include the implementation of inappropriate treatment regimens that do not enable patients to achieve goal and poor patient compliance. For example, it is widely acknowledged that most patients require two or more antihypertensive drugs to achieve BP goal; however, physicians may be reluctant to employ such treatment strategies. The aim of this review is to explore factors that contribute to poor hypertension control rates and how to overcome these, including the rationale for selecting combination therapy, with particular reference to angiotensin II receptor blocker combinations.

Managing hypertension in patients with type 2 diabetes mellitus

PURPOSE

Current guideline recommendations for effective strategies to optimize the treatment of patients with concomitant hypertension and type 2 diabetes mellitus are reviewed.

SUMMARY

Current estimates indicate that 20 million people in the United States have diabetes, 90-95% of whom have type 2 diabetes mellitus. Type 2 diabetes mellitus is associated with an increased risk of premature death from cardiovascular disease (CVD), stroke, and end-stage renal disease. Hypertension is an extremely common comorbidity in patients with type 2 diabetes mellitus. The coexistence of hypertension in patients with type 2 diabetes is particularly destructive because of the strong linkage of the two conditions with CVD, stroke, progression of renal disease, and diabetic nephropathy. Current guidelines, including those issued by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure, the National Kidney Foundation, and the American Diabetes Association, provide evidence-based recommendations for the treatment of hypertension in patients with type 2 diabetes mellitus. However, studies indicate that guidelines are not widely followed. Therefore, the beneficial effects of appropriate hypertension treatment observed in clinical trials are often not recognized in clinical practice. Pharmacists are ideally positioned to help improve guideline implementation and patient outcome.

CONCLUSION

Pharmacists must become more vigilant about following current guidelines for the treatment of patients with concomitant hypertension and type 2 diabetes mellitus. Strategies such as patient education and medication assessment can help to optimize care for these patients and slow the progression to diabetic nephropathy.

The HOPE (Heart Outcomes Prevention Evaluation) Study and its consequences

The HOPE study was a 19 country, prospective randomized trial in which the ACE-inhibitor Ramipril but not Vitamin E significantly reduced the risk of future cardiovascular events in a high-risk population of men and women, including many with diabetes. The benefits were present in all sub-groups, independent of the presence or absence of diabetes, hypertension, evidence of cardiovascular disease, microalbuminuria, blood pressure lowering, the use of aspirin, lipid-lowering or antihypertensive medication. It provided clear evidence that Ramipril should safely and cost-effectively be used in individuals not known to have low ventricular ejection fraction or heart failure but at high-risk of cardiovascular events. It was also beneficial in patients with renal insufficiency, reducing progression of proteinuria and development of new microalbuminuria. It provided micro- and macrovascular benefits in people with diabetes, reduced the development of new cases of diabetes and showed a positive and graded association between the waist-to-hip ratio and the risk of developing diabetes. Sub-studies completed and on-going into the predictive role of natriuretic peptides, infectious and inflammatory markers, provide insight into possible mechanisms of action of Ramipril.

Risk of hypertension and reduced kidney function after acute gastroenteritis from bacteria-contaminated drinking water

BACKGROUND

The long-term health consequences of acute bacterial gastroenteritis remain uncertain. We studied the risk of hypertension and reduced kidney function after an outbreak of acute gastroenteritis due to contamination of a regional drinking water supply with Escherichia coli O157:H7 and Campylobacter species.

METHODS

A total of 1958 adults with no known history of hypertension or kidney disease before the outbreak participated in a long-term follow-up study. Of the participants, 675 had been asymptomatic during the outbreak, 909 had had moderate symptoms of acute self-limited gastroenteritis, and 374 had had severe symptoms that necessitated medical attention. The outcomes of interest were a diagnosis of hypertension or the presence of reduced kidney function and albuminuria during the follow-up period.

RESULTS

After a mean follow-up of 3.7 years after the outbreak, hypertension was diagnosed in 27.0% of participants who had been asymptomatic during the outbreak and in 32.3% and 35.9% of those who had had moderate and severe symptoms of acute gastroenteritis respectively (trend p = 0.009). Compared with the asymptomatic participants, those with moderate and severe symptoms of gastroenteritis had an adjusted relative risk of hypertension of 1.15 (95% confidence interval [CI] 0.97-1.35) and 1.28 (95% CI 1.04-1.56) respectively. A similar graded association was seen for reduced kidney function, defined as the presence of an estimated glomerular filtration rate below 60 mL/min per 1.73 m2 (trend p = 0.03). No association was observed between gastroenteritis and the subsequent risk of albuminuria.

INTERPRETATION

Acute bacterial gastroenteritis necessitating medical attention was associated with an increased risk of hypertension and reduced kidney function 4 years after infection. Maintaining safe drinking water remains essential to human health, as transient bacterial contaminations may have implications well beyond a period of acute self-limited illness.

Renal failure and ACE inhibition: how much is too much?

The dose-response relationship between pharmacological blockade of the renin-angiotensin system (RAS) and angiotensin II concentration in the circulation, on the one hand, and decrease of blood pressure, on the other hand, has been well established. In contrast it is currently unclear which dose of ACE inhibitors and/or angiotensin receptor blockers is optimal for nephroprotection. Clinical studies are rendered quite complex by an early decrease of glomerular filtration after RAS blockade and by side effects at higher doses such as renal sodium loss, hyperkalemia, anemia, etc. Animal experiments and recent clinical studies suggest that the doses of ACE inhibitors or angiotensin receptor blockers required for maximal reduction of proteinuria (as a surrogate marker) and for optimal nephroprotection (retardation of the loss of glomerular filtration) exceed those required for maximal lowering of blood pressure. Ongoing studies try to define the relative merits of high dose monotherapy (ACE inhibitors or angiotensin receptor blockers) versus a combination therapy of the two.

Diabetic dyslipidaemia: insights for optimizing patient management

BACKGROUND

Lipid abnormalities in people with diabetes are likely to play an important role in the development of atherogenesis. These lipid disorders include potentially atherogenic quantitative (increased triglyceride levels and decreased high-density lipoprotein-cholesterol [HDL-C] levels) and qualitative abnormalities of lipoproteins (changes in lipoprotein size, increase in triglyceride content of low-density lipoprotein (LDL) and HDL, glycation of apoproteins and increased susceptibility of LDL to oxidation). Guidelines from the two main diabetes organizations, the International Diabetes Federation and the American Diabetes Association, recommend the aggressive management of diabetic dyslipidaemia to reduce the risk of cardiovascular disease (CVD). Statins are the first choice pharmacological therapy to address diabetic dyslipidaemia due to their effectiveness at lowering LDL-C levels in patients with diabetes. Fibrates (peroxisome proliferator-activated receptor [PPAR]alpha ligands) target another aspect of dyslipidaemia by lower ing triglycerides (to a greater extent than statins) and raising HDL-C levels, especially when baseline levels are low. The PPARgamma agonist, pioglitazone appears to affect lipid metabolism by decreasing plasma triglycerides, increasing HDL-C and decreasing the number of small, dense atherogenic LDL particles.

SCOPE

This paper provides a review of the current literature (based on searches of MEDLINE and EMBASE from 1985 to 2005, inclusive) supporting the recommendations for the management of dyslipidaemia among patients with type 2 diabetes, including new strategies involving drug combinations that achieve good glycaemic and lipidaemic control that could potentially reduce the morbidity and mortality associated with type 2 diabetes.