Daytime BP variability predicts CV outcomes, death in T2D patients

Short-term variability of ambulatory blood pressure (BPV), particularly daytime diastolic BPV, is associated with future development of macrovascular complications and death, reveals a study. In addition, it also improves cardiovascular risk discrimination in patients with type 2 diabetes (T2D).

The investigators, over a median of 11.2 years, followed 640 patients who had performed 24-h ambulatory BP monitoring at baseline. They calculated daytime, night-time, and 24-h systolic and diastolic BPV parameters (standard deviations and variation coefficients).

Multivariate Cox analysis, adjusted for risk factors and mean BP, was conducted to assess the associations between BPV and the occurrence of microvascular (retinopathy, microalbuminuria, renal function deterioration, peripheral neuropathy) and macrovascular complications (total cardiovascular [CV] events, major adverse CV events [MACEs]), and cardiovascular and all-cause mortality.

Finally, the investigators evaluated improvements in risk discrimination using the C-statistic and Integrated Discrimination Improvement (IDI) index.

During follow-up, 186 patients developed a CV event (150 MACEs) and 237 died (107 from CV diseases); 155 had new-onset or worsened diabetic retinopathy, 200 achieved the renal composite outcome (124 newly developed microalbuminuria and 102 deteriorated renal functions), and 170 developed or worsened peripheral neuropathy.

Daytime diastolic BPV was the strongest predictor for all CV outcomes and mortality, with hazard ratios ranging from 1.27 (95 percent confidence interval [CI], 1.09–1.48) for all-cause death to 1.55 (95 percent CI, 1.29–1.85) for MACEs; it also improved CV risk discrimination, with increases in C-statistic of up to 0.026 and IDIs of up to 22.8 percent.

Notably, none of the BPV parameters was predictive of any microvascular outcome.