Blood Pressure Targets < 130 mm Hg Might Not Benefit Patients with Diabetes
EBM Focus - Volume 11, Issue 10
Read the full EBM Focus and earn CME credit. Reference - BMJ 2016 Feb 24;352:i717 (level 2 [mid-level] evidence) Much attention has been generated surrounding optimal blood pressure targets in patients with hypertension. Recent trials have suggested that systolic blood pressure targets as low < 120 mm Hg may decrease mortality and cardiovascular events compared to the currently recommended target of < 140 mm Hg (N Engl J Med 2015 Nov 26;373(22):2103, Lancet 2009 Aug 15;374(9689):525). However, patients with diabetes were excluded from these trials. There is some evidence suggesting lower blood pressure targets may improve the risk of stroke and nephropathy in patients with hypertension and diabetes (Circulation 2011 Jun 21;123(24):2799, N Engl J Med 2010 Apr 29;362(17):1575), and the Canadian Hypertension Education Program recommends systolic blood pressure targets < 130 mm Hg for patients with diabetes (Hypertension Canada 2015). To try to determine the optimum blood pressure target in patients with diabetes, a recent systematic review analyzed 49 randomized trials assessing antihypertensive treatments in 73,738 patients with diabetes (mostly type 2 diabetes). Twenty-four of these trials were limited to patients with diabetes and the remaining 25 included trials were subgroup analyses of patients with diabetes from larger patient populations. The mean reduction in systolic blood pressure with treatment was 10.2 mm Hg and patients were followed for an average of 3.7 years. The impact of antihypertensive treatment on all-cause and cardiovascular mortality is presented in the table below. In patients who attained a systolic blood pressure < 130 mm Hg, treatment was associated with a nonsignificant increase in the risk of both all-cause and cardiovascular mortality. The only significant reduction in mortality with treatment was in patients attaining a systolic blood pressure between 130-140 mm Hg.
While there has recently been increasing emphasis on lower blood pressure targets, the results of this systematic review suggest that in patients with hypertension and diabetes, a systolic blood pressure < 130 mm Hg may not be beneficial and might actually increase the risk of mortality. These results were consistent in an analysis evaluating patients by baseline blood pressure. In that analysis, patients with a baseline blood pressure < 140 mm Hg showed an increased risk of cardiovascular mortality and a nonsignificant increase in risk of all-cause mortality with treatment. In patients with a baseline blood pressure > 140 mm Hg, antihypertensive treatment did appear to lower the risk of mortality and cardiovascular outcomes. Overall, these results suggest that for patients with diabetes and hypertension, blood pressure treatments should be tailored to keep systolic blood pressure at or just below 140 mm Hg. For more information, see the Hypertension treatment in patients with diabetes topic in DynaMed Plus. DynaMed users click here.