TIGHT BLOOD-PRESSURE CONTROL AND RISK OF MACROVASCULAR AND MICROVASCULAR COMPLICATIONS IN TYPE-2 DIABETES - UKPDS 38

Objective: To determine whether tight control of blood pressure preven ts macrovascular and microvascular complications in patients with type 2 diabetes. Design: Randomised controlled trial comparing tight contr ol of blood pressure aiming at a blood pressure of <150/85 mm Hg (with the use of an angiotensin converting enzyme inhibitor captopril or a beta blocker atenolol as main treatment) with less tight control aimin g at a blood pressure of <.180/105 mm Hg. Setting 20 hospital based cl inics in England, Scotland, and Northern Ireland. Subjects: 1148 hyper tensive patients with type 2 diabetes (mean age 56, mean blood pressur e at entry 160/94 mm Hg); 758 patients were allocated to tight control of blood pressure and 390 patients to less tight control with a media n follow up of 8.4 years. Main outcome measures: Predefined clinical e nd points, fatal and non-fatal, related to diabetes, deaths related to diabetes, and all cause mortality. Surrogate measures of microvascula r disease included urinary albumin excretion and retinal photography. Results: Mean blood pressure during follow up was significantly reduce d in the group assigned tight blood pressure control (144/82 mm Hg) co mpared with the group assigned to less tight control (154/87 mm Hg) (P < 0.0001). Reductions in risk in the group assigned to tight control c ompared with that assigned to less tight control were 24% in diabetes related end points (95% confidence interval 8% to 38%) (P= 0.0046), 32 % in deaths related to diabetes (6% to 51%) (P= 0.019), 44% in strokes (11% to 65%) (P= 0.013), and 37% in microvascular end points (11% to 56%) (P= 0.0092), predominantly owing to a reduced risk of retinal pho tocoagulation. There was a non-significant reduction in all cause mort ality. After nine years of follow up the group assigned to tight blood pressure control also had a 34% reduction in risk in the proportion o f patients with deterioration of retinopathy by two steps (99% confide nce interval 11% to 50%) (P= 0.0004) and a 47% reduced risk (7% to 70% ) (P = 0.004) of deterioration in visual acuity by three lines of the early treatment of diabetic retinopathy study (ETDRS) chart. After nin e years of follow up 29% of patients in the group assigned to tight co ntrol required three or more treatments to lower blood pressure to ach ieve target blood pressures. Conclusion: Tight blood pressure control in patients with hypertension and type 2 diabetes achieves a clinicall y important reduction in the risk of deaths related to diabetes, compl ications related to diabetes, progression of diabetic retinopathy, and deterioration in visual acuity.