not justified based on recent analyses of non-dipping in children with CKD

This is a pilot, crossover trial in which the investigator will determine if retiming of one anti-hypertensive medication from morning to evening can effectuate normal blood pressure dipping patterns in children and adolescents 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.

Inclusion Criteria:

• Male or female child/adolescent up to 18 years of age with CKD
• estimated glomerular filtration rate (eGFR) of 30 to 90 ml/min/1.73 m2
• diagnosed with hypertension and on a stable dose of anti-hypertensive medication(s) for at least 3 months
• Non-dipping identified on ABPM

Exclusion Criteria:

• history of organ transplantation, oncological disease, or dialysis
• inability to complete 24-hour ABPM or 24-hour urine collection
• Children less than 6 years of age will be excluded, as they often are unable to complete a successful ABPM study (≥ 40 readings, with 1 reading per hour of sleep)
• Currently on diuretic medications.