A study has found an increase in long-term elevated levels of the stress hormone cortisol, in obese children compared with normal weight children. The results suggest a link between long-term stress response and childhood obesity.
As the rate of childhood obesity continues to rise, intervention strategies are being formed to help provide children with opportunities for healthy lifestyle choices. We have previously reported on some of these initiatives:
Researchers from the Netherlands were interested in finding out whether chronically elevated cortisol levels are associated with obesity in children. Children were recruited for the study at the obesity outpatient clinic of the Department of Pediatrics from two hospitals in the Netherlands. A total of 20 obese children and 20 normal weight children, between 8 and 12 years old, were included in the study.
The study measured cortisol in the scalp hair of the children, since typically used saliva, urine, or serum, are affected by daily variations in cortisol secretion. Cortisol in scalp hair represents the average exposure of cortisol over time. A 1cm sample of hair represents one month of cortisol exposure.
Results of the study revealed a difference in cortisol levels in the hair of obese children (25pg/ml) compared with normal weight children (17pg/ml). In addition, a significant correlation was found between cortisol levels and BMI, as well as waist circumference. The researchers suggest that this long-term exposure to cortisol in this group of children is indicative of long-term activation of the hypothalamus-pituitary-adrenal (HPA) axis. Following activation of the HPA axis, cortisol is released as part of the stress response. The researchers state that it is still unknown whether long-term exposure to high levels of cortisol is a cause, or effect of obesity, and further research is needed. However, this study has demonstrated for the first time that obese children have greater long-term cortisol exposure compared with normal weight children, potentially providing a new target for intervention.
An intervention study introducing behavioural and lifestyle counseling to reduce stress is already underway at Yale University, and Yale Stress Center, New Haven, Connecticut, United States. The study is recruiting families of children between the ages of 2 and 5 years, with at least one parent who is obese, with high parenting stress, according to scores from questions from the Parenting Stress Index. The study will examine the effects of mindfulness-based stress reduction, nutrition counseling, and physical activity counseling as stress reduction interventions for parents of preschoolers, in an effort to reduce both parental and child stress.
Erica van den Akker, M. Veldhorst, G. Noppe, C. Kok, S. Mekic, M. Jongejan, J. Koper and E. van Rossum. Increased Scalp Hair Cortisol Concentrations in Obese Children. Journal of Clinical Endocrinology & Metabolism, December 2013
Clinicaltrials.gov “Family Based Mindfulness Intervention” available from: https://www.clinicaltrials.gov/ct2/show/NCT01974102?term=stress+AND+childhood+obesity&rank=1 Last Accessed: April 15, 2015.
Image courtesy of David Castillo Dominici at FreeDigitalPhotos.net
Written by Deborah Tallarigo, PhD