title: Effect of antihypertensive treatment at different blood pressure levels in patients with diabetes mellitus: systematic review and meta-analyses.
abstract: OBJECTIVE
  To assess the effect of antihypertensive treatment on mortality and cardiovascular morbidity in people with diabetes mellitus, at different blood pressure levels.
  
  
  METHODS
  Systematic review and meta-analyses of randomised controlled trials.
  
  
  METHODS
  CENTRAL, Medline, Embase, and BIOSIS were searched using highly sensitive search strategies. When data required according to the protocol were missing but trials were potentially eligible, we contacted researchers, pharmaceutical companies, and authorities.
  
  
  METHODS
  Randomised controlled trials including 100 or more people with diabetes mellitus, treated for 12 months or more, comparing any antihypertensive agent against placebo, two agents against one, or different blood pressure targets.
  
  
  RESULTS
  49 trials, including 73,738 participants, were included in the meta-analyses. Most of the participants had type 2 diabetes. If baseline systolic blood pressure was greater than 150 mm Hg, antihypertensive treatment reduced the risk of all cause mortality (relative risk 0.89, 95% confidence interval 0.80 to 0.99), cardiovascular mortality (0.75, 0.57 to 0.99), myocardial infarction (0.74, 0.63 to 0.87), stroke (0.77, 0.65 to 0.91), and end stage renal disease (0.82, 0.71 to 0.94). If baseline systolic blood pressure was 140-150 mm Hg, additional treatment reduced the risk of all cause mortality (0.87, 0.78 to 0.98), myocardial infarction (0.84, 0.76 to 0.93), and heart failure (0.80, 0.66 to 0.97). If baseline systolic blood pressure was less than 140 mm Hg, however, further treatment increased the risk of cardiovascular mortality (1.15, 1.00 to 1.32), with a tendency towards an increased risk of all cause mortality (1.05, 0.95 to 1.16). Metaregression analyses showed a worse treatment effect with lower baseline systolic blood pressures for cardiovascular mortality (1.15, 1.03 to 1.29 for each 10 mm Hg lower systolic blood pressure) and myocardial infarction (1.12, 1.03 to 1.22 for each 10 mm Hg lower systolic blood pressure). Patterns were similar for attained systolic blood pressure.
  
  
  CONCLUSIONS
  Antihypertensive treatment reduces the risk of mortality and cardiovascular morbidity in people with diabetes mellitus and a systolic blood pressure more than 140 mm Hg. If systolic blood pressure is less than 140 mm Hg, however, further treatment is associated with an increased risk of cardiovascular death, with no observed benefit.
authors.affiliation: Department of Public Health and Clinical Medicine, Medicine, Umeå University, SE-901 87 Umeå, Sweden mattias.brunstrom@umu.se.
authors.forename: Mattias
authors.initials: M
authors.lastname: Brunström
authors.affiliation: Department of Public Health and Clinical Medicine, Medicine, Umeå University, SE-901 87 Umeå, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Carlberg
mesh_terms: D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology*; D003925:Diabetic Angiopathies / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000401:mortality / Q000503:physiopathology*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000959:Antihypertensive Agents