Combination therapy with an ACE inhibitor and an angiotensin receptor blocker for diabetic nephropathy: a meta-analysis.
OBJECTIVE
Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) prevent the progression of diabetic nephropathy (DN). Studies suggest that combination renin-angiotensin-aldosterone system (RAAS)-inhibiting therapy provides additive benefit in DN. However, these studies are small in size. We performed a meta-analysis of studies investigating combination therapy for DN.


METHODS
Studies were identified through a search of medline, embase, cinahl and the Cochrane Database. All trials involving combined ACEI and ARB for slowing progression of DN were included. The primary end point was 24-h urinary protein excretion. Blood pressure, serum potassium and glomerular filtration rate (GFR) were secondary end points.


RESULTS
In the 10 included trials, 156 patients received ACEI + ARB and 159 received ACEI only. Most studies were 8-12 weeks in duration. Proteinuria was reduced with ACEI + ARB (P = 0.01). This was associated with significant statistical heterogeneity (P = 0.005). ACEI + ARB was associated with a reduction in GFR [3.87 ml/min (7.32-0.42); P = 0.03] and a trend towards an increase in serum creatinine (6.86 micromol/l 95% CI -0.76-13.73; P = 0.09). Potassium was increased by 0.2 (0.08-0.32) mmol/l (P < 0.01) with ACEI + ARB. Systolic and diastolic blood pressure were reduced by 5.2 (2.1-8.4) mmHg (P < 0.01) and 5.3 (2.2-8.4) mmHg (P < 0.01), respectively.


CONCLUSIONS
This meta-analysis suggests that ACEI + ARB reduces 24-h proteinuria to a greater extent than ACEI alone. This benefit is associated with small effects on GFR, serum creatinine, potassium and blood pressure. These results should be interpreted cautiously as most of the included studies were of short duration and the few long-term studies (12 months) have not demonstrated benefit.
Jennings
D L
DL
Wayne State University, Eugene Applebaum College of Pharmacy and Health Sciences, Detroit, MI, USA.
Kalus
J S
JS
Coleman
C I
CI
Manierski
C
C
Yee
J
J
D000328:Adult; D000368:Aged; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use*; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D003928:Diabetic Nephropathies / Q000150:complications / Q000188:drug therapy*; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011945:Receptors, Angiotensin / Q000627:therapeutic use
D047228:Angiotensin II Type 1 Receptor Blockers; D057911:Angiotensin Receptor Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D011945:Receptors, Angiotensin