A recent study published in the British Medical Journal suggests that people with diabetes and high
blood pressure can be treated with any antihypertensive agent and not
necessarily an RAS blocker.
There are several drugs available for the treatment of hypertension and the choice of antihypertensive drug is sometimes determined by the presence of any additional condition in the patient For example, if the patient also suffers from an increase in heart rate, a beta blocker like atenolol that reduces heart rate, as well as blood pressure, may be preferred.
Patients with diabetes often suffer from high blood pressure and are at a high risk for heart and kidney disease. Over the years, people with diabetes and high blood pressure were preferably prescribed drugs that act on the renin-angiotensin-aldosterone system (RAS) for the treatment of their hypertension. This preference was based on large studies, which demonstrated that these drugs prevent heart and kidney disease in diabetes patients, which they are prone to. Drugs that act through RAS include angiotensin converting enzyme (ACE) inhibitors like ramipril and lisinopril and angiotensin receptor blockers (ARBs) like losartan, valsartan and candesartan.
The researchers did not find evidence that RAS inhibitors were better than other antihypertensive drugs in reducing death, heart diseases like heart attack and angina, stroke, and kidney disease like an end-stage renal disease in patients with diabetes. However, data on milder forms of kidney disease like doubling of Creatinine levels in the blood could not be obtained.
The finding of the study contrasts with the guidelines laid down by several committees which indicate that these antihypertensive drugs should be used preferentially in diabetes patients. However, it agrees with the 2013 Society of Cardiology/European Society of Hypertension guidelines and the 2014 Eighth Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure which suggest that any antihypertensive can be used in diabetes patients, especially in those patients without kidney disease. In addition, the fact still remains that RAS blockers are superior to calcium channel blockers in prevention of heart failure.
This study expands the choice of antihypertensive drugs for the physician that can be used in diabetes patients. Many diabetes patients require more than one antihypertensive agent to control their blood pressure. The bottom-line is, whichever antihypertensive drug is used, it is important to maintain the blood pressure normal in patients with diabetes to prevent complications.
Dr. Sanjeev Nair, Senior Consultant Nephrologist, Comments:
"The article being discussed has several limitations that should caution one from comprehensively changing current clinical practice. The findings of this study are the result of a meta-analysis of previously conducted studies with very different structures that does not lend itself to easy comparison. The ALLHAT trial, which had one of the largest study populations and was included in this analysis, did not study the effect of medication on urine protein leak, which is the earliest complication of diabetic renal involvement. Multiple trials have shown a benefit of RAAS blockade in decreasing urinary protein leak and delaying onset of End Stage Renal Disease in earlier stages. Therefore, while it maybe safe to conclude that in diabetics with hypertension and without any other comorbidities, all classes of anti-hypertensives are equally efficacious, in the specific scenario of a diabetic with renal involvement who requires an anti-hypertensive ACE inhibitors or ARBs should still be the first choice drug till a sufficiently powered prospective randomized controlled trial that does a direct comparison proves equally beneficial."
- Bangalore S, Fakheri R, Toklu B, Messerli FH. Diabetes mellitus as a compelling indication for use of renin angiotensin system blockers: systematic review and meta-analysis of randomized trials. BMJ 2016;352:i438. http://dx.doi.org/10.1136/bmj.i438