Endothelial Function in Obese Adolescents

Summary

Childhood obesity is perhaps the most significant public health problem in the most developed countries and is rapidly becoming so in developing countries. National Health and Nutrition Examination Survey data shows a 3-fold increase in the prevalence of obesity in childhood, over past few decades. Furthermore, childhood obesity has markedly contributed to the prevalence of the metabolic syndrome and type 2 diabetes in U.S. children. Alarmingly, there is increasing evidence that atherosclerosis develops silently during childhood in obese children. In the Bogalusa Heart Study, pediatric autopsy studies showed a clear relationship between the number and severity of risk factors, principally obesity, with atherosclerosis in both the aorta and coronary arteries. Increased intimal medial thickness (IMT) was not present among obese adults who had been normal weight as children, emphasizing the cumulative effects of childhood obesity persisting into adulthood. Thus, the need for primary prevention of cardiovascular disease beginning in childhood is strongly suggested.

Conditions

• Insulin Resistance
• Glucose Intolerance
• Obesity
• Atherosclerosis

Interventions

OTHER

Reactive hyperemia peripheral artery tonometry (Rh-PAT)

Pulse volume is measured by a finger plethysmographic device which are sensed by a pressure transducer and transferred to a computer where the signal is amplified, displayed and stored (EndoPAT, Itamar Medical). Fingertip probes are placed on the index finger of both hands and 5 minutes of baseline recording are obtained. Blood flow is then occluded in one arm for 5 minutes, using a standard blood pressure cuff. Recording continues in both fingers during occlusion and for 5 minutes after release of the cuff. The RH-PAT index is calculated as the ratio of the average pulse amplitude in the post-hyperemic phase divided by the average baseline amplitude, with normalization to the signal in the control arm to compensate for any systemic changes.

OTHER

Blood levels for glucose, insulin, lipids and adipocytokines

A fasting laboratory evaluation will include chemistry panel (basic metabolic, liver function tests), CBC, lipid profile, urinalysis and HbA1c. All obese recruited subjects after a 12 hour fast will undergo an OGTT using a glucose load of 1.75 g/kg body weight with a maximum of 75 g. Blood samples will be collected for insulin, glucose, leptin, adiponectin, hsCRP and FFA. Serum and urine will be stored at -70 degrees Centigrade for measuring markers of oxidative stress and adipocytokines (including TNF-α, PAI-1)

Sponsors & Collaborators

• Montefiore Medical Center

  lead OTHER

Principal Investigators

• Chhavi Agarwal, MD · Montefiore Medical Center

Study Design

Allocation

NON_RANDOMIZED

Purpose

DIAGNOSTIC

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

12 Years

Max Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2011-03-31

Primary Completion

2013-06-30

Completion

2014-01-31

Countries

• United States

Study Locations