Ambulatory Hypertension in Pediatric Patients With Sickle Cell Disease and Its Association With End-Organ Damage

Background Sickle cell disease (SCD), a chronic hemolytic disorder, results in cumulative end-organ damage affecting major organs such as the cardiovascular, renal, and central nervous systems. Effects of modifiable risk factors, such as blood pressure (BP), on the development of end-organ complications in SCD have not been well studied, particularly among the pediatric population. Relative hypertension in patients with SCD increases their risks of stroke, cardiovascular complications, and death. The primary hypothesis of this study was that abnormal BP patterns are common among patients with SCD and they impact end-organ complications. Methods Patients with SCI) (HbSS, HbS beta 0) were enrolled from the Children's Hospital at Montefiore (N = 100). For each patient, demographic data were collected, biochemical variables in urine and blood samples were analyzed, BP was determined with ambulatory blood pressure monitoring (ABPM), and an echocardiogram was performed. The prevalence of abnormalities in BP parameters was defined, and their relationships with measures of SCD severity and end-organ damage were assessed. Results Sufficient ABPM data were available for 67 patients. Enrolled children were 13 +/- 4 years (40% were males). Assessment of diurnal variation demonstrated that 81% of patients had abnormal systolic nocturnal dipping and 61% had abnormal diastolic nocturnal dipping. Abnormalities in the diurnal pattern were associated with reticulocytosis and hyperfiltration. Microalbuminuria was present in 19% (n = 13) of patients, of which 77% (n =10) were females (p = 0.014). Diastolic load and abnormal nocturnal dipping were associated with hyperfiltration but not with microalbuminuria. Conclusions BP abnormalities detected with ABPM in SCD patients are prevalent and perhaps are a risk factor for endorgan complications. Further studies are required to identify the mechanisms underlying these relationships and their longitudinal changes.