UKPDS 38 evaluated the effect of hypertension control on diabetic outcomes. The study involved the randomization of 1148 hypertensive patients (mean age, 56.4 years), to either tight blood pressure control (blood pressures less than 150/85)with either an angiotensin-converting enzyme (ACE) inhibitor (captopril) or a beta-blocker (atenolol), or to less tight control (blood pressures less than 180/105) without these drugs. The actual mean blood pressures obtained were 144/82 in the tight control group and 154/87 in the “less tight.”
Endpoints were identical to those in the main study just described. Mean follow-up time was 8.4 years.
Tight blood pressure control reduced diabetes-related endpoints by 24% (95% CI, 8%-38%; p = 0.0046), diabetes-related deaths by 32% (CI, 6%-51%; p = 0.019; NNT = 15), and stroke by 44% (CI, 11%-65%; p = 0.013) compared to less tight control. Microvascular endpoints were reduced by 37% (CI, 11%-56%; p = 0.0092), with 35% reduction in risk of retinal photocoagulation (p = 0.023). There was no difference in all-cause mortality. There were also no differences between captopril or atenolol in terms of treatment benefits.
The DCCT and UKPDS give us important information related to the rationale for treatment of diabetes mellitus in late life. It is clear that microvascular and macrovascular events can be influenced by careful control of diabetes mellitus. As a result, the management of both blood pressure and blood sugar in diabetes mellitus has a sound rationale.
The use of ACE inhibitor therapy in minimizing the development of and the progress of renal damage as measured by micro- and clinical-grade albuminuria has now become an important standard of care in the management of type 2 diabetes. Whether ACE inhibitor itself or blood pressure reduction alone is the factor reducing albuminuria is not fully answered. Additionally, the importance of high lipids as a strong risk factor for future cardiovascular disease in diabetic individuals is gaining attention, and aggressive treatment is becoming the norm.