Chronotherapy in Children With Chronic Kidney Disease

Normally blood pressure declines by at least 10% from daytime to nighttime. In children with chronic kidney disease (CKD), often this does not happen (termed "non-dipping"). This study is a pilot, randomized cross-over trial. The main purpose of this study is to investigate whether non-dipping can be modified with retiming of anti-hypertensives in children with CKD. This is important because in adults, non-dipping has been associated with increased cardiovascular disease risk and more rapid progression of kidney disease. Thus, identification of how to modify this in children with CKD, may lead to future randomized controlled trials to evaluate whether chronotherapy improves outcomes in this population, which is at high risk for morbidity and mortality in adulthood. The primary objective of this study is to determine whether retiming of one anti-hypertensive to the evening will increase nocturnal systolic blood pressure change (%) in children with CKD, hypertension and non-dipping. The secondary objective of this study is to determine whether retiming of one anti-hypertensive to the evening will increase nocturnal diastolic blood pressure change (%) in children with CKD, hypertension and non-dipping. Another secondary objective is to determine if the proportion of subjects classified as having a non-dipping pattern is significantly lower on evening dosing of anti-hypertensives.