Obesity Hypertension and Endothelial Dysfunction in Pediatric Patients

Obesity Hypertension and Endothelial Dysfunction in Pediatric Patients Jen-Jar Lin, M. D. , Ph. D. Division of Nephrology Department of Pediatrics

Hypopnea in Pediatric Patients with Obesity Hypertension Question: • Why some obese pediatric patients are hypertensive and some are not? • Is sleep apnea one of the contributing factors for obesity hypertension in pediatric patients?

Hypothesis Obesity Hypertension OSAS

Table 4 Correlation coefficients in obese patients

Forward Stepwise multiple regression analysis obese patients (n = 56); PSG variables log transformed Dependent variable: SBPscore or DBPscore Independent variables: BMIscore, Arousal Index, HI, AHI • SBPscore(R 2 = 23%): BMIscore (R 2 = 14%, p = 0. 004) HI (R 2 = 7%, p = 0. 04) • DBPscore (R 2 = 28%): HI (R 2 = 18%, p = 0. 01) BMIscore (R 2 = 10%, p = 0. 001)

Obese patients

Identification of early surrogate markers for end-organ damage and CVD in pediatric patients with hypertension or obesity

• Both obesity and hypertension are independent risk factors of CVD and mortality in adults • Childhood obesity and hypertension are associated with the future development of obesity and systolic hypertension in adulthood • However, since CVD is usually not manifested until later in adulthood, data regarding the effect of pediatric antihypertensive therapy on the future CVD risk is not known. • End-organ damage from hypertension or obesity, such as LVH or microalbuminuria, may take years to develop.

Identification of early surrogate markers for future CVD or end-organ damage in pediatric hypertensive patients will allow timely interventions and determination of treatment efficacy • Endothelial dysfunction and an increased intimamedia thickness (IMT) has been shown in adults with hypertension, DM, or obesity. • Carotid IMT is an early CVD risk marker in adults. • An increased aortic IMT has been demonstrated in children with familial hypercholesterolemia or IDDM, which is associated with their diastolic BP.

Goal of the study To examine if endothelial dysfunction and intima-media thickness can be early surrogate markers for CVD or end-organ damage markers in pediatric patients with hypertension

Endothelial dysfunction assessed by the hyperemic response to ischemia in brachial artery

Right brachial artery, before 4 -min occlusion of the forearm Mean diameter = 4. 23 mm

Right brachial artery, at 1. 5 min after forearm occlusion Mean diameter = 4. 6 mm , 10% increase in diameter

Right brachial artery, at 5 min after forearm occlusion Mean diameter = 4. 47 mm

Intima-Media Thickness (IMT) of abdominal aorta, right brachial artery, and common carotid artery

Right brachial artery, mean IMT = 0. 4 mm

Significance If an increased IMT and/or endothelial dysfunction Is demonstrated to be an early surrogate marker for end-organ damage in pediatric patients with hypertension, it can be used as the endpoint and the guide for antihypertensive therapy in these patients.