Blood pressure treatment levels and choice of antihypertensive agent in people with diabetes mellitus: an overview of systematic reviews.

OBJECTIVE: Multiple systematic reviews address the effect of antihypertensive treatment in people with diabetes. Here, we summarize current systematic reviews concerning antihypertensive treatment effect at different blood pressure (BP) levels, and relative treatment effect of different antihypertensive agents. METHODS: We searched MEDLINE, BIOSIS, DARE and CDSR during years 2005-2016. Eligibility criteria, number of trials and participants, outcomes analysed, statistical methods used for data synthesis, and principal results were extracted for each review. Review quality was assessed using the assessment of multiple systematic reviews tool. RESULTS: We found four reviews concerning BP treatment level. These consistently showed that the effect of antihypertensive treatment on mortality, cardiovascular disease and coronary heart disease was attenuated at lower BP levels. If SBP was more than 140 mmHg, treatment reduced all-cause and cardiovascular mortality, cardiovascular disease, stroke, myocardial infarction and heart failure. If SBP was less than 140 mmHg, treatment increased the risk of cardiovascular death. We found eight reviews concerning choice of agent. We found no difference between angiotensin-converting enzyme inhibitors, angotensin receptor blockers, beta-blockers, calcium channel blockers and diuretics in preventing all-cause or cardiovascular mortality, combined cardiovascular disease, coronary heart disease and end-stage renal disease. Minor differences exist for stroke and heart failure. Data were limited on people with type 1 diabetes and very elderly patients with type 2 diabetes. None of the reviews concerning choice of agent included all relevant trials. CONCLUSION: The available evidence supports treatment in people with type 2 diabetes and SBP more than 140 mmHg, using any of the major antihypertensive drug classes.