Differences in segmental hair cortisol concentration analysis among children and adolescents with overweight and obesity, their parents, and normal weight peers.

PURPOSE: Dysregulation of the stress system via incidental long exposure to glucocorticoids (GCs) can lead to weight gain. In addition, family and maternal stress can also have an impact on children's weight. Hair is used in several studies to evaluate cortisol (GC) levels in children and adolescents with excess weight as a retrospective stress biomarker, depending on the hair length the cortisol measurement depicting different time periods. We aimed to investigate whether there is a difference among segmental hair cortisol concentration (HCC) analysis between children and adolescents with overweight and obesity, their mothers, and normal weight peers. METHODS: This study recruited 25 children aged 6-14 years with a body mass index (BMI) ≥ 85th centile and their mothers, as well as 20 children of the same age with a BMI < 85th centile. Hair cortisol concentration was measured using electrochemiluminescence immunoassay. RESULTS: Segmental HCC analysis exhibited gradually decreasing values in all participants as segments of hair were more distantly located from the scalp. A positive correlation was found between BMI z-score and HCC of the first segment of hair in children and adolescents with elevated BMI (b = 1.84, p = 0.033), as well as with maternal HCC / of an only child (b = 15.77, p = 0.01). There were no associations between mother-child dyads and children and adolescents of different BMI groups, even though minors with excess weight exhibited higher HCC levels in all segments of hair in comparison to their normal weight counterparts. CONCLUSIONS: Hair cortisol of all participants exhibited a gradually declining concentration. More studies with larger samples and more sensitive methods of analysis are warranted in order to draw firmer conclusions.

Difference in Hair Cortisol Concentrations between Obese and Non-Obese Children and Adolescents: A Systematic Review.

Childhood obesity has been linked to physical and psychological comorbidities that can be carried into adulthood. A bidirectional link between body weight and the stress system appears to exist, as cortisol may affect the regulation of appetite, while adiposity can affect cortisol secretion. Among the biological tissues used to evaluate cortisol concentrations, scalp hair can provide retrospective measures. The aim of this systematic review was to investigate the difference in hair cortisol concentrations between obese and non-obese minors ≤ 19 years of age. Children and adolescents with genetic, somatic or psychiatric comorbidities were excluded. The work was conducted following the PRISMA guidelines, using prespecified search terms in the Pubmed database. The initial search yielded 56 studies, while the last step of the screening procedure concluded in 9 observational studies. Among them, the results could be characterized as inconclusive. Five of them demonstrated significantly higher hair cortisol concentrations in obese children and adolescents than normal weight subjects. On the contrary, the remaining four found no statistically significant differences in hair cortisol concentrations between obese and non-obese subjects. Different methodologies applied, and confounding factors could explain the inconsistency in the findings. Further research is needed to provide more solid results.