ASSOCIATIONS BETWEEN GENETICALLY PREDICTED PULSE PRESSURE AND TARGET ORGAN DAMAGE: A MENDELIAN RANDOMIZATION STUDY

Abstract

Objective: Large-artery stiffness (LAS) leads to an increased pulse pressure (PP) and is thought to induce target organ damage (TOD). However, causal associations of PP have not been unequivocally assessed in humans. We aimed to investigate the bi-directional associations between genetically predicted increased PP and phenotypes of TOD using Mendelian randomization (MR). Design and method: Bi-directional MR analyses were performed to investigate associations between genetically predicted PP and: left ventricular mass (LVM), myocardial interstitial fibrosis, heart failure (HF), chronic kidney disease (CKD), cognitive performance, brain white matter hyperintensities (WMH), type 2 diabetes (T2D) and preeclampsia (PrE). Multivariable MR was conducted to investigate the effect of PP on significant outcomes, independently of mean arterial pressure (MAP). Results: For a 10-mmHg increase in genetically-predicted PP, the odds ratios (ORs) were 1.113 (95%CI=1.085-1.137, P<0.001) for HF, 1.075 (95%CI=1.048-1.103, P<0.001) for CKD, 1.137 (95%CI=1.102-1.173, P<0.001) for T2D, and 1.435 (95%CI=1.256-1.638, P<0.001) for PrE. Similarly, a 10-mmHg increase in genetically-predicted PP was associated with a greater LVM (beta estimate=3.527 g/m2, 95%CI=3.026-4.028, P<0.001). The association of genetically predicted PP on risk of HF, CKD and T2D was independent of genetically-predicted MAP. Bidirectional MR also supported a causal effect of genetically predicted log-odds of T2D on PP (beta estimate=0.527 mmHg, 0.396-0.658, P<0.001), and PrE on PP (beta estimate=2.365 mmHg, 0.783-3.947, P=0.003) indicating a potential bidirectional relationship. Conclusions: We provide evidence supporting causal associations between PP and T2D, CKD, HF and increased risk of LV hypertrophy in humans, consistent with the deleterious effects of LAS on LV afterload and on microvascular integrity in low-resistance target organs. Early interventions aimed at lowering LAS may lead to lowering the risk of adverse outcomes.