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Researchers at Children’s Hospital Los Angeles Find Link Between Snoring and Obesity

Sleep apnea is associated with insulin resistance

CONTACT: Ellin Kavanagh at 323-361-8505 or ekavanagh@chla.usc.edu. Sally L. Davidson Ward, MD

LOS ANGELES (August 9, 2012) – Researchers at Children’s Hospital Los Angeles found that sleep apnea was associated with insulin resistance, a metabolic dysfunction that correlates with obesity. “This study sheds light on the early development of metabolic syndrome,” said Sally L. Davidson Ward, MD,  head of the division of Pediatric Pulmonology at Children’s Hospital Los Angeles and a co-author on the study. “It leads us to hypothesize whether treatment of sleep-related breathing disorder at an early age could improve metabolic function and positively impact the development of obesity and diabetes.”

“Understanding the development of pediatric obesity requires a multidisciplinary approach such as this collaboration between the divisions of Pediatric Pulmonology and Endocrinology at Children’s Hospital and the Viterbi School of Engineering at USC,” said Brent Polk, MD, director of The Saban Research Institute of Children’s Hospital Los Angeles and professor of pediatrics and biochemistry and molecular biology at the Keck School of Medicine of the University of Southern California.

Sleep apnea, also known as sleep-related breathing disorder, is common in obese individuals and has been linked to insulin resistance in adults, with conflicting findings in children, until now. Insulin resistance, a condition where insulin becomes less effective at lowering blood sugar, occurs in obese and diabetic individuals.

Childhood obesity is a worldwide health problem yet the causes have not been completely identified.  In addition to food intake and physical activity, genetics, environment and social factors appear to play a role.  In this study, obese adolescent Latino males who had been referred to the clinic for snoring were studied. This group was intentionally limited by ethnicity, gender and age since these factors are known to have an effect on the insulin response.  After fasting overnight, study subjects were followed using the frequently sampled intravenous glucose tolerance test to measure glucose metabolism. This method allows simultaneous estimations of both insulin resistance and pancreatic B-cell action and is the gold standard for evaluating glucose homeostasis.

Investigators found that subjects who experienced a lot of sleep disruption were less sensitive to insulin and had less responsive pancreatic B-cells. They also found that even small decreases in oxy-hemoglobin, the oxygen supplied to the body by red blood cells, was associated with lower insulin sensitivity.  The investigators postulated that during episodes of sleep apnea when the subject is not breathing, less oxygen is available leading to changes in key physiological pathways effecting metabolism.

This paper, published in the July 11 issue of Pediatric Research was co-authored by Daniel J. Lesser, MD, Rajeev Bhatia, MD, Winston H. Tran, PhD, Flavia Oliveira, PhD, Ricardo Ortega, MA, Thomas G. Keens, MD, Steven D Mittelman, MD, PhD, Michael C. K. Khoo, PhD, and Sally L. Davidson Ward, MD.

Click here to see the research paper.

About Children’s Hospital Los Angeles 

Children's Hospital Los Angeles has been named the best children’s hospital in California and among the top five in the nation for clinical excellence with its selection to the prestigious US News & World Report Honor Roll.  Children’s Hospital is home to The Saban Research Institute, one of the largest and most productive pediatric research facilities in the United States, is one of America's premier teaching hospitals and has been affiliated with the Keck School of Medicine of the University of Southern California since 1932.

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