The impact of blood pressure variability on subclinical ventricular, renal and vascular dysfunction, in patients with hypertension and diabetes.

BACKGROUND

Blood pressure variability (BPV) was proved as a cardiovascular risk factor. One of its mechanisms is related to arterial stiffness and ventriculo-arterial coupling; however its impact on subclinical cardiovascular dysfunction has not been evaluated yet.

OBJECTIVES

To assess the relationship between BPV on 24 hours, and subclinical left ventricle (LV), renal, and vascular dysfunction in diabetic and hypertensive patients.

MATERIAL AND METHODS

We studied 56 patients (57±9 years, 29 men) with mild-to-moderate hypertension and type 2 diabetes, no cardiovascular disease, normal ejection fraction and normal renal function. 24 hours ambulatory blood pressure monitoring (ABPM) was used to assess BPV, daytime (d) and night time (n), by: 1. mean (M); 2. standard deviation of mean (SD); 3. variance (Vr); 4. coefficient of variation (CV); 5. day/night variation: reverse dippers, non-dippers, dippers and extreme dippers; conventional and 2D speckle tracking echo to assess LV function; myocardial deformation was measured as global longitudinal strain (GLS). Endothelial (flow mediated dilation, FMD) and arterial function (intima media-thickness, IMT; pulse wave velocity, PWV), microalbuminuria were tested.

OUTCOMES

Daytime BPV correlates inversely with subclinical myocardial function evaluated through GLS. Daytime systolic BPV correlates positively with IMT (all rho > 0.30, all p < 0.05). Also, there is a significantly inverse correlation between mean BP and GLS. We found a direct correlation between mean BP, but not BPV, and microalbuminuria (all rho > - 0.30 and all p < 0.05). We found no correlation between BPV and FMD, PWV. There were no differences for GLS, microalbuminuria and FMD between dipper groups.

CONCLUSIONS

In diabetic patients with mild-to-moderate hypertension, increased daytime blood pressure variability correlates with subclinical left ventricular dysfunction and arterial function (IMT), while microalbuminuria correlates with elevated blood pressure, but not with blood pressure variability.