Diastolic pressure in type 2 diabetes: can target systolic pressure be reached without "diastolic hypotension"?

Abstract

The practicality of vigorous lowering of systolic pressure in diabetes to <130 mmHg remains uncertain. Baseline blood pressure data from several recent trials indicate that, in diabetic subjects, there is nearly a fourfold excess in systolic pressure (the difference between baseline pressure and target pressure) over diastolic pressure with respect to the recommended systolic/diastolic target pressure of <130/80 mmHg. Additionally, systolic pressure was 2-3 mmHg higher and diastolic pressure was 1-3 mmHg lower in diabetic hypertensive than in nondiabetic hypertensive individuals, which adds approximately 4 mmHg to pulse pressure and also to the difference between the excess systolic and excess diastolic pressure. We attempted to force (titrate both systolic and excess diastolic pressure) systolic and diastolic blood pressure to <130/85 mmHg based on Joint National Committee VI guidelines in the setting of a clinical practice in 257 diabetic patients. Although target systolic pressure was attained in a third of this cohort, in 57% of the patients, the attained diastolic pressure was <or=70 mmHg. Patients with final diastolic pressure <70 mmHg were older, had a higher prevalence of coronary artery disease, and had higher initial systolic and pulse pressures. Review of achieved blood pressure in studies such as the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) indicates that a significant fraction of the diabetic subjects' diastolic pressure was also driven down to <70 mmHg or even <60 mmHg. Thus, attempted lowering of blood pressure to target systolic pressure is associated with inordinate lowering of diastolic pressure in a significant number of patients. Whether the benefits of tight systolic control to <130 mmHg outweigh the risks of excessive diastolic reduction, especially in older diabetic subjects or diabetic patients with coronary artery disease, remains unresolved.