Chevy Chase, MD--Obese children naturally produce higher levels of a key stress hormone than their normal weight peers, according to new research accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism.
The body produces the hormone cortisol when a person experiences stress. When a person faces frequent stress, cortisol and other stress hormones build up in the blood and, over time, can cause serious health problems. This study measured cortisol in scalp hair, which reflects long-term exposure and has been proposed to be a biomarker for stress. The study is the first to show obese children have chronically elevated levels of cortisol.
"We were surprised to find obese children, as young as age 8, already had elevated cortisol levels," said one of the study's authors, Erica van den Akker, MD, PhD, of Erasmus MC-Sophia Children's Hospital in Rotterdam, The Netherlands. "By analyzing children's scalp hair, we were able to confirm high cortisol levels persisted over time."
The observational case-control study analyzed hair samples from 20 obese children and 20 normal weight children to measure long-term cortisol levels. Each group included 15 girls and 5 boys between the ages of 8 and 12.
Obese subjects had an average cortisol concentration of 25 pg/mg in their scalp hair, compared to an average concentration of 17 pg/mg in the normal weight group. The hormone concentrations found in hair reflect cortisol exposure over the course of about one month.
"Because this study took an observational approach, more research will determine the cause of this phenomenon," van den Akker said. "We do not know whether obese children actually experience more psychological stress or if their bodies handle stress hormones differently. Answering these key questions will improve our understanding of childhood obesity and may change the way we treat it."
Other authors of the study include: M. Veldhorst, G. Noppe, C. Kok and S. Mekic of Erasmus MC-Sophia Children's Hospital; M. Jongejan of Sint Franciscus Gasthuis in Rotterdam; and J. Koper and E. van Rossum of Erasmus MC in Rotterdam.
The study, "Increased Scalp Hair Cortisol Concentrations in Obese Children," was published online, ahead of print.
Founded in 1916, The Endocrine Society is the world's oldest, largest and most active organization devoted to research on hormones and the clinical practice of endocrinology. Today, The Endocrine Society's membership consists of over 17,000 scientists, physicians, educators, nurses and students in more than 100 countries. Society members represent all basic, applied and clinical interests in endocrinology. The Endocrine Society is based in Chevy Chase, Maryland. To learn more about the Society and the field of endocrinology, visit our site at http://www.