Managing hypertension in patients with renal disease and diabetes

The authors of the 1999 Canadian recommendations for the management of hypertension state that "hypertension in people with diabetes should be treated to obtain target blood pressure lower than 130/80 mm Hg."1 This grade C recommendation is supported by evidence from the HOT2 and UKPDS 383 studies insofar as the diastolic target is concerned. However, we question the systolic target of 130 mm Hg given our review of the evidence from these 2 studies.

In the HOT study, the mean systolic blood pressure achieved by the group randomized to a diastolic target of < 80 mm Hg was 139.7 mm Hg. In the UKPDS 38 study, the mean systolic blood pressure achieved in the group randomized to "tight" blood pressure control was 144 mm Hg. Therefore, the evidence with regard to the systolic target for control of blood pressure in diabetic patients with hypertension points to 140 mm Hg rather than 130 mm Hg less.

The high prevalence of systolic blood pressures in the range of 130 to 140 mm Hg would mandate additional treatment for a large number of people if the Canadian guidelines were to be closely followed. Of note, the British Hypertension Society recommends that clinicians attempt to achieve a target of less than 140 mm Hg systolic blood pressure in hypertensive patients with type II diabeties.4 Is there additional evidence that led the authors to recommend a lower systolic target of 130 mm Hg?