Objective: To investigate whether antihypertensive treatment is beneficial to patients with diabetes mellitus when their blood pressure (BP) is below 140/90 mm Hg (1 mm Hg = 0.133 kPa).
Methods: MEDLINE, EMBASE, IPA database and secondary resources were searched with terms including blood pressure, hypertension and anti-hypertension drug.
Inclusion criteria: random control study; subjects were patients with diabetes mellitus or impaired glucose tolerance; endpoint BP ≤ 140/90 mm Hg; endpoint BP between two groups had significant differences. There were 16 studies meet inclusive criteria with a total of 51 470 patients. RR and 95%CI were used as index to judge the difference of clinical outcomes between aggressive antihypertensive treatment group and standard antihypertensive treatment group. RevMan5.0 software was used for statistical analysis.
Results: When BP of patients with diabetes mellitus were below 140/90 mm Hg, anti-hypertensive treatment could reduce incidence rate of cardiovascular event (RR 0.91, 95%CI 0.87 - 0.96, P = 0.0004) and stroke (RR 0.75, 95%CI 0.63 - 0.88, P = 0.0005), and increased incidence rate of symptomatic hypotension (RR 3.57, 95%CI 1.41 - 11.20, P = 0.03) and hyperpotassemia (RR 1.57, 95%CI 1.05 - 2.33, P = 0.03). There were no significant differences in all-cause mortality (RR 0.94, 95%CI 0.87 - 1.01, P = 0.08), cardiovascular mortality (RR 0.95, 95%CI 0.85 - 1.08, P = 0.05), myocardial infarction (RR 0.93, 95%CI 0.82 - 1.05, P = 0.26), heart failure (RR 0.90, 95%CI 0.76 - 1.06, P = 0.21) between the aggressive antihypertensive treatment group and standard antihypertensive treatment group.
Conclusions: When blood pressure of patients with diabetes mellitus was below 140 mm Hg, there was little benefit from aggressive antihypertensive treatment, and the risk of serious adverse events even increased.