Association of systolic blood pressure with macrovascular and microvascular complications of type 2 diabetes (UKPDS 36): prospective observational study

Objective To determine the relation between systolic blood pressure over ti me and the risk of macrovascular or microvascular complications in patients dth type 2 diabetes. Design Prospective observational study. Setting 23 hospital based clinics in England, Scotland and Northern Ireland Participants 4801 white, Asian Indian, and Afro-Caribbean UKPDS patients, whether randomised or not to treatment, were included in analyses of incide nce; of these, 3642 were included in analyses of relative risk, Outcome measures Primary predefined aggregate clinical outcomes: any compli cations or deaths related to diabetes and all cause mortality. Secondary ag gregate outcomes: myocardial infarction, stroke, lower extremity amputation (including death from peripheral vascular disease), and microvascular dise ase (predominantly retinal photocoagulation). Single end points: non-fatal heart failure and cataract extraction Risk reduction associated with a 10 m m Hg decrease in updated mean systolic blood pressure adjusted for specific confounders Results The incidence of clinical complications was significantly associate d with systolic blood pressure, except for cataract extraction. Each 10 mm Hg decrease in updated mean systolic blood pressure was associated with red uctions in risk of 12% for any complication related to diabetes (95%, confi dence interval 10% to 14%, P < 0.0001), 15% for deaths related to diabetes (12% to 18%, P< 0.0001), 11% for myocardial infarction (7% to 14%, P< 0.000 1), and 13% for microvascular complications (10% to 16%, P< 0.0001). No thr eshold of risk was observed for any end point. Conclusions In patients with type 2 diabetes the risk of diabetic complicat ions was strongly associated with raised blood pressure. Any reduction in b lood pressure is likely to reduce the risk of complications, with the lowes t risk being in those with systolic blood pressure less than 120 mm Hg.