Abstract
Background: Loss of the normal nocturnal decline in blood pressure (BP), known as non-dipping, is a potential measure of cardiovascular risk identified by ambulatory blood pressure monitoring (ABPM). We sought to determine whether non-dipping is a useful marker of abnormal vascular function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus (pSLE). Methods: Twenty subjects 9-19 years of age with pSLE underwent ABPM, peripheral endothelial function testing, carotid-femoral pulse wave velocity/analysis for aortic stiffness, and carotid intima-media thickness. We assessed the prevalence of non-dipping and other ABPM abnormalities. Pearson or Spearman rank correlation tests were used to evaluate relationships between nocturnal BP dipping, BP load (% of abnormally elevated BPs over 24-hours) and vascular outcome measures. Results: The majority (75%) of subjects had inactive disease, with mean disease duration of 3.2 years (±2.1). The prevalence of non-dipping was 50%, which occurred even in the absence of nocturnal or daytime hypertension. Reduced diastolic BP dipping was associated with poorer endothelial function (𝒓 0.5, p=0.04). Intima-media thickness was significantly greater in subjects with non-dipping (mean standard deviation score of 3.0 vs 1.6, p=0.02). In contrast, higher systolic and diastolic BP load were associated with increased aortic stiffness (𝜌 0.6, p=0.01 and 𝜌 0.7, p<0.01, respectively), but not with endothelial function or intima-media thickness. Conclusion: In a pSLE cohort with low disease activity, isolated nocturnal BP non-dipping is prevalent and associated with endothelial dysfunction and atherosclerotic changes. In addition to hypertension assessment, ABPM has a promising role in risk stratification and understanding heterogeneous mechanisms of cardiovascular disease in pSLE.
Nocturnal blood pressure dipping as a marker of endothelial function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus
