137 - Abnormal Nocturnal Blood Pressure Dipping Patterns: A Potential Biomarker of Cardiovascular Risk in Pediatric Patients with CCHS and ROHHAD

Poster Number: 137
Publication Number: 137.3009

Background: Congenital Central Hypoventilation Syndrome (CCHS) is a rare disorder of autonomic nervous system (ANS) regulation and control of breathing caused by heterozygous PHOX2B gene mutations. Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is an ultra-rare disorder of ANS regulation and control of breathing, with a typical presentation of a 20-30-pound weight gain over 3-12-months between ages 1.5-10 years. Recent evidence suggests patients with CCHS and ROHHAD may be at increased risk for cardiovascular events as they reach adulthood, but objective biomarkers anticipating that risk are lacking. In children with obstructive sleep apnea, another population with respiratory dysfunction during sleep, recent evidence suggests that diminished or absent nocturnal blood pressure (BP) dipping may be a biomarker for increased cardiovascular risk.

Objective: Investigate abnormal nocturnal BP dipping patterns in patients with CCHS and ROHHAD to determine if BP dipping may be a potential biomarker for cardiovascular risk.

Design/Methods: 24-hour ambulatory BP monitoring (ABPM) was performed in 14 patients (11 with CCHS, aged 15-24 years; 3 with ROHHAD, aged 17-19 years), generating 24 recordings. Systolic (SBP) and diastolic (DBP) BP values were recorded by sphygmomanometer, with measurements every 15 minutes. Time spent awake and asleep was determined by polysomnography. Abnormal nocturnal BP dipping was defined as a drop < 10% or a non-dip (represented by a negative value) in either SBP or DPB compared to daytime values (Bankir et al.) (Figure 1). Nocturnal BP dip percentages were calculated for each ABPM recording.

Results: Abnormal nocturnal SBP and DBP dipping was identified in 4 of 11 patients with CCHS (5/17 ABPM recordings; Table 1) and 3 of 3 patients with ROHHAD (6/6 ABPM recordings for SBP but 2/6 for DBP; Table 2). Night-to-night differences in nocturnal dipping were noted in patients with CCHS and ROHHAD.

Conclusion(s): We observed a high occurrence of abnormal nocturnal BP dipping with night-to-night variation in our pilot cohort of youth with CCHS and ROHHAD. Longitudinal monitoring and ABPM studies in patients with CCHS and ROHHAD offer the potential to evaluate the correlation between abnormal BP dipping and cardiovascular risk.