Blunted cortisol response to stress is associated with higher body mass index in low-income preschool-aged children

Abstract

No known studies have tested the hypothesis that a blunted pattern of cortisol reactivity to stress, which is often found following exposure to chronic life stressors, is associated with a higher body mass index (BMI) in very young children. Low-income children (n = 218, mean age 56.6 (range: 38.1 to 78.5; SD 7.0) months, 49.1% male, 56.4% white, 16.1% black, 11.5% Hispanic/Latino) participated in a series of behavioral tasks designed to elicit stress. Cortisol was sampled in saliva 5 times during the protocol, and area under the curve (AUC), representing total cortisol output during stress elicitation, was calculated. Children were weighed and height measured and body mass index (BMI) z-score was calculated. Linear regression was used to evaluate the association between cortisol AUC and BMI z-score, controlling for child age, sex, and race/ethnicity (non-Hispanic white vs. not); primary caregiver weight status (overweight, defined as BMI > 25 vs. not); and family income-to-needs ratio. Mean child BMI z-score was 0.88 (SD = 1.03). Mean cortisol AUC was 6.11 μg/dL/min (SD = 10.44). In the fully adjusted model, for each 1-standard deviation unit decrease in cortisol AUC, the child's BMI z-score increased by 0.17 (SE 0.07) standard deviation units (p <.02). A blunted cortisol response to stress, as is often seen following chronic stress exposure, is associated with increased BMI z-score in very young children. Further work is needed to understand how associations between stress, cortisol, and elevated body mass index may develop very early in the lifespan.

Internalizing and externalizing problems in obese children and adolescents: associations with daily salivary cortisol concentrations

“…61 in this study, cortisol levels did not vary significantly with age or sex. A small number of other studies [62][63][64] examining either basal cortisol levels or cortisol responses to stress confirm these results; however, other studies do not. 65,66 in our sample, although OC had a significantly lower AUC compared to controls, this difference was lost after inserting the effect of age.…”

Influence of Acute Physical Activity on Stress Reactivity in Obese and Normal Weight Children: A Randomized Controlled Trial

“…A study on a selected low-income group of preschool children found similar associations of increased BMI (BMI z-scores) and blunted HPA stress reactivity [17]. This limited capacity to respond to challenging conditions might be the result of limited coping strategies, i.e.…”

“…This limited capacity to respond to challenging conditions might be the result of limited coping strategies, i.e. maladaptive or unhealthy strategies such as potential changes in food consumption to manage stress conditions [17, 58]. …”

“…To our knowledge, only two studies have investigated HPA and only few have investigated ANS stress reactivity related to obesity in pre-pubertal children: A blunted cortisol response to stress was associated with increased BMI z-score in preschoolers [17] and in adolescents aged 11–17 years [18]. On the other side, a Chinese study revealed heightened cortisol reactivity in obese children aged 12–13 years [19].…”

“…On the other side, a Chinese study revealed heightened cortisol reactivity in obese children aged 12–13 years [19]. Thus, in children and adolescents, hypo- and hyperreactivity to stress relate to greater BMI cross-sectionally and longitudinally [17-20]. Regarding the ANS system, higher BP reactivity to laboratory stress was associated with a greater abdominal waist and waist-to-hip ratio in adolescents [21, 22] and a greater HR reactivity with percentage body fat following an interpersonal stressor in pre-pubertal children [23].…”