Prognostic Value of Low Diastolic 24-H Blood Pressure in Type 2 Diabetic Patients in a Follow-Up of 4.7 Years

Background: The prognV0W3ostic implications of the 24 hours ambulatory blood pressure monitoring (AMBP) have been progressively established but some issues remain controversial about the prognostic value of circadian blood pressure (BP) profile in some high-risk populations, namely the diabetics. Methods: We followed, for 4.7 +/- 3.5 years, 262 type 2 diabetic patients without previous cardiovascular events after AMBPs, on the occurrence of a combination of coronary events and stroke. Results: There were 36 events (18 coronary and 18 strokes), 7 of them fatal. Half the population showed a non-dipping pattern (non-dippers plus reverse dippers) and the later conveyed a lower survival rate free from strokes (log rank 6.99; P < 0.01) as related to the dipper patients, in the Kaplan-Meier curves. There was a clear J shaped curve for the distribution of the 24-hour diastolic blood pressure (24H DBP) for global and coronary events, that persisted even after the exclusion of patients with isolated systolic hypertension. Furthermore, in the subgroup with higher (> 75 mmHg) 24H DBP, but not in the group with 24H DBP below 75 mmHg, the 24H systolic BP value was an independent predictor of global events in the multivariate analysis (HR 0.03; 95% CI 0.09 - 0.57; P < 0.002), showing decreased event-free survival in the Kaplan-Meier curves (log rank 9.15; P < 0.003). Conclusions: In our population of diabetic type 2 patients 24H DBP had an impact on prognosis on its own, particularly for its lower values. Thus low values of 24H DBP are associated with high cardiovascular risk.