The impact of blood pressure variability on cardiovascular and renal outcomes in patients with and without diabetes: insights from the Anglo-Scandinavian Cardiac Outcomes Trial

Objective: Blood pressure variability (BPV) has emerged as an independent risk factor for cardiovascular outcomes. This study evaluated the relationship between visit-to-visit BPV and cardiovascular events, renal outcomes, and mortality in individuals with and without diabetes, using data from the ASCOT trial. Methods: BPV was assessed from SBP measurements collected over a 5-year follow-up in 18 528 participants from the ASCOT trial, including 4910 individuals with diabetes and 13 618 without diabetes Participants were stratified according to levels of SBP and BPV, and outcomes were compared using Cox proportional hazards models adjusted for baseline confounders, Findings: There was a positive relationship between cardiovascular and renal outcomes and higher mean SBP in those with and without diabetes, but this association was markedly attenuated following adjustment for confounding variables. In those with diabetes, higher BPV (>13) was strongly associated with increased risks of nonfatal myocardial infarction (MI) and fatal coronary heart disease (CHD) [hazard ratio 1.76, 95% confidence interval (95% CI) 1.29–2.39], stroke (hazard ratio 2.41, 95% CI 1.67–2.90), total coronary events (hazard ratio 1.94, 95% CI 1.53–2.45), total CV events (hazard ratio 2.39, 95% CI 1.97–2.89), renal impairment (hazard ratio 1.69, 95% CI 1.26–2.26, P < 0.001), and mortality (hazard ratio 1.52, 95% CI 1.19–1.94) compared with the reference group (all P < 0.001). These associations, albeit attenuated, persisted after adjustment for confounders. In those with well controlled SBP (≤135 mmHg), elevated BPV conferred significant residual risk. Those allocated to amlodipine-based regimen had a significantly reduced risk of stroke (hazard ratio 0.74, 95% CI 0.56–0.97) and total cardiovascular events (hazard ratio 0.81, 95% CI 0.71–0.93) (vs those allocated to atenolol-based treatment), an effect partly attributable to BPV reduction. Conclusion: Long-term BPV is a critical cardiovascular and renal risk factor in individuals with diabetes and should be incorporated into risk assessment where feasible. On the basis of available evidence, long-acting calcium channel blockers should be incorporated into treatment strategies to improve cardiovascular outcomes.