Evidence-based approach for managing hypertension in type 2 diabetes

Abstract

Blood pressure (BP) control is a critical part of managing patients with type 2 diabetes. Perhaps it is the single most important aspect of diabetes care, which unlike hyperglycemia and dyslipidemia can reduce both micro- and macrovascular complications. Hypertension is more prevalent in individuals with diabetes than general population, and in most cases its treatment requires two or more pharmacological agents (about 30% of individuals with diabetes need 3 or more medications to control BP). In this article we describe the key evidence that has contributed to our understanding that reduced BP translates into positive micro- and macrovascular outcomes. We review the data supporting current recommendation for BP target < 130/80 mmHg. Two studies suggest that a lower BP goal could be even more beneficial. We also present the comparative benefits of various antihypertensive drugs in reducing diabetes-related micro- and macrovascular complications. Finally we propose an evidence-based algorithm of how to initiate and titrate antihypertensive pharmacotherapy in affected individuals. Overall, achieving BP < 130/80 mmHg is more important than searching for the "best" antihypertensive agent in patients with diabetes.

Keywords: adherence; blood pressure control; clinical inertia; fixed dose combination; treatment protocol.

Figure 1

Algorithm for treatment of hypertension in inividuals with diabetes. Maximize dose before starting the next drug. First line = ACEi or ARB (equivalence seen in DETAIL ONTARGET and VALIANT76).

1. Both reduce microalbuminuria and rate of nephropathy independently of their antihypertensive effect.

2. ACEi preferred over ARB (indirect evidence for cardiovascular outcomes; SCOPE, VALUE and TRANSCEND72).

3. Recommend against concomitant use of ARB with ACEi (ONTARGET and VALIANT76).

Second line = CCB or diuretic

1. Dihydropyridine CCB favored over diuretic (ACCOMPLISH and GUARD83) or in the presence of electrolyte anomalies.

2. Diuretic preferred in heart failure or edematous conditions.

3. Loop diuretic recommended if GFR ≤ 30 mL/min due to marked state of fluid overload.

4. If needed, CCB and diuretic can be combined.

Third line = β-blocker, primarily due to side effect profile. However, it is indicated in all patients with established CAD and MI. Fourth line = Aldosterone antagonist (ASCOT-BPLA86). Fifth line = Renin inhibitor or α-blocker, not enough comparative data from clinical trials for clear recommendation. Peripheral α-blocker, due to orthostatic hypotension and results of ALLHAT. It could be used earlier in patients with symptomatic BPH. ^arenal artery stenosis, hyperaldosteronism, Cushing’s syndrome or pheochromocytoma. Abbreviations: BP, blood pressure; ACEi, angiotensin converting enzyme inhibitor; ARB, angiotensin receptor blocker; CCB, calcium channel blocker; CAD, coronary artery disease; MI, myocardial infarction; HTN, hypertension; GFR, glomerular filtration rate; BPH, benign prostate hyperplasia.