The objectives of this proposal are to investigate the associations between blood pressure and hypertensive end-organ injury in children. To test the hypothesis that abnormal circadian BP patterns in children are associated with hypertensive end-organ injury, 24-hour ambulatory BP monitoring (ABPM) will be performed and end-organ injury will be assessed by measuring: 1) left ventricular mass index by echocardiography, 2) carotid artery intima-media thickness by ultrasound, 3) microalbuminuria by 24-hour urine collection, and 4) retinal vasculopathy by digital retinal photography. To test the hypothesis that children who are referred by primary care providers for elevated casual blood pressure are representative of the overall population of hypertensive children, we will perform ABPM and end- organ injury assessment in two patient groups: unsolicited referrals to a pediatric hypertension program and case-identification by systematic school-based BP screening. School-based BP screening will be performed in approximately 10,000 children aged 12-16 in the Houston Independent School District by a team of nursing faculty and students. These groups will be compared with respect to demographics and clinical parameters derived from ABPM and the indices of end-organ injury. Current definitions of pediatric hypertension are based on population percentiles of casual BP measurements and not on the risk of hypertensive end-organ injury. Twenty-four hour ABPM provides a more complete and accurate representation of the daily circadian BP patterns and is superior to casual BP in the prediction of end-organ injury in adults. Few data exist on the relationship between ambulatory BP data and end-organ injury in children. A further barrier to the study of pediatric hypertension is the low prevalence of the condition, estimated at 1-2% of the pediatric population. This limitation has made adequate patient accrual difficult and predisposed studies to referral bias. The proposed studies will add significantly to our ability to practice evidence-based medicine regarding the evaluation and management of hypertensive children.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Mentored Patient-Oriented Research Career Development Award (K23)
Project #
1K23HL004217-01A2
Application #
6321875
Study Section
Special Emphasis Panel (ZHL1-CSR-F (F1))
Program Officer
Schucker, Beth
Project Start
2001-04-05
Project End
2006-04-04
Budget Start
2001-04-05
Budget End
2002-04-04
Support Year
1
Fiscal Year
2001
Total Cost
$124,998
Indirect Cost
Name
University of Texas Health Science Center Houston
Department
Pediatrics
Type
Schools of Medicine
DUNS #
City
Houston
State
TX
Country
United States
Zip Code
77225
Sorof, Jonathan M; Turner, Jennifer; Franco, Kathy et al. (2004) Characteristics of hypertensive children identified by primary care referral compared with school-based screening. J Pediatr 144:485-9
Sorof, Jonathan M; Lai, Dejian; Turner, Jennifer et al. (2004) Overweight, ethnicity, and the prevalence of hypertension in school-aged children. Pediatrics 113:475-82
Sorof, Jonathan M; Turner, Jennifer; Martin, David S et al. (2004) Cardiovascular risk factors and sequelae in hypertensive children identified by referral versus school-based screening. Hypertension 43:214-8
Sorof, Jonathan M; Alexandrov, Andrei V; Cardwell, Gina et al. (2003) Carotid artery intimal-medial thickness and left ventricular hypertrophy in children with elevated blood pressure. Pediatrics 111:61-6
Sorof, Jonathan M; Alexandrov, Andrei V; Garami, Zsolt et al. (2003) Carotid ultrasonography for detection of vascular abnormalities in hypertensive children. Pediatr Nephrol 18:1020-4
Sorof, Jonathan M; Poffenbarger, Tim; Franco, Kathy et al. (2002) Isolated systolic hypertension, obesity, and hyperkinetic hemodynamic states in children. J Pediatr 140:660-6
Sorof, Jonathan M; Cardwell, Gina; Franco, Kathy et al. (2002) Ambulatory blood pressure and left ventricular mass index in hypertensive children. Hypertension 39:903-8