Farah N. Ali, MD 

Title of Project:  Cardiovascular Risk in Obesity: The role of a novel risk factor, Fibroblast Growth Factor-23 (FGF23), in left ventricular   hypertrophy.

 Abstract  

 Obesity has negative health consequences for children, including increased cardiovascular disease and high blood pressure, which can persist throughout their lifetime. There are many factors that contribute to both obesity and high blood pressure, but it is apparent that some children have a higher risk of developing cardiovascular disease than others. The factors that contribute to increased cardiovascular risk in some children are not well-understood.

In patients with chronic kidney disease, fatal events due to cardiovascular disease are much higher than in the general population. It is becoming increasingly apparent in patients with chronic kidney disease that a novel hormone, Fibroblast Growth Factor 23 (FGF23), is linked to both cardiovascular problems and death. Studies in animals have shown that adipose (fat) cells may increase blood FGF23 levels. Since obesity is a well-known precursor for chronic kidney disease, this pilot study aims to determine if blood levels of FGF23 may be an early mediating factor in the development of cardiovascular disease in obese patients who do not have clinical expression of chronic kidney disease.

We plan to study 40 obese children, ages 10-17 years, with either normal or high blood pressure and who do not have chronic kidney disease.  We will measure their blood levels of FGF23 and evaluate their heart muscle thickness. Analyses will determine if: 1) blood FGF23 rises above normal levels in obese children not having chronic kidney disease, and; 2) if levels of this hormone correlate with heart muscle thickness. If the relationships between FGF23 and cardiovascular risk are shown, this novel information may lead to identification of unique therapeutic targets. 

 Jie Deng, PhD. 

Title of Project: Measuring Brown Fat Adiposity Using Magnetic Resonance Imaging for Assessment of Pediatric Obesity Development - A Pilot Study.

Abstract 

Obesity results from an imbalance between energy intake and expenditure. To understand the etiology of obesity, it is essential to determine the role of adipose tissue (fat) in regulating energy balance. There are 2 types of adipose tissue in mammals: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is the primary site of energy storage; BAT is an adaptive thermogenesis organ that dissipates energy directly by heat. Functional deficient or hyperactive BAT may contribute to development of obesity. One hypothesis is that obese children have lower level of BAT than healthy weight children, and the BAT volume is inversely related to body mass index. This study aims to characterize and measure BAT in children using non-invasive, radiation-free Magnetic Resonance Imaging (MRI). MRI is now at the forefront in the assessment of body adipose tissues and disorders of fat metabolism. State-of-the-art MRI techniques provide information on mass and structure, and functional and physiological measures that yield information on metabolic and biological functions.

In this pilot study, 48 (24 male and 24 female) children ages 8-14 years will be recruited. Four groups (healthy weight vs. obese, prepubertal vs. pubertal stages) will be formed with 12 children in each group. Subjects will undergo a 20 minutes MRI scan covering from neck to lower abdomen areas. The MRI will be able to differentiate BAT from WAT by evaluations of proportion of fat tissue, mitochondrial content, and blood supply. Given that BAT can be well differentiated from WAT, the volume of BAT will be measured in all subjects and compared between four groups to investigate the relation of BAT with obesity, puberty status and sex differences. This information may lead to development of ways to increase energy expenditure as a potential target for obesity treatment.

 Megan McCarville, MD, MPH 

Title of Project:  Recognition of Obesity, Overweight, and High Blood Pressure in a Pediatric Tertiary Care Setting: Existing Practice and Areas for Improvement.

Abstract: 

Research suggests that childhood overweight and obesity and their complications may be under recognized by primary care clinicians.  Little research has been done on the role of pediatric subspecialty physicians in diagnosing pediatric overweight and obesity and their complications.  Improving subspecialist recognition of overweight and obesity may be important in filling a currently-existing gap in children’s medical care.  We aim to identify the prevalence of overweight and obesity and elevated blood pressure (BP) among patients aged 2-17 years presenting for outpatient and primary care at a single pediatric tertiary care institution over a 1 year period.  Analyses will evaluate how often providers diagnose overweight, obesity, and elevated B.  This project will provide data that can be used for the development a hospital-wide quality improvement project to address recognition of and counseling about obesity and high BP.  In addition, we aim to understand the processes of care that subspecialty physicians use to identify overweight and obesity and elevated BP and to characterize subspecialty physicians’ attitudes and perceived barriers towards identifying overweight and obesity and elevated BP in their practices.