title: 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: 38.1-78.5; 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<0.02). 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.
authors.affiliation: University of Michigan, United States. Electronic address: alimill@umich.edu.
authors.forename: Alison L
authors.initials: AL
authors.lastname: Miller
authors.forename: Caitlin
authors.initials: C
authors.lastname: Clifford
authors.forename: Julie
authors.initials: J
authors.lastname: Sturza
authors.forename: Katherine
authors.initials: K
authors.lastname: Rosenblum
authors.forename: Delia M
authors.initials: DM
authors.lastname: Vazquez
authors.forename: Niko
authors.initials: N
authors.lastname: Kaciroti
authors.forename: Julie C
authors.initials: JC
authors.lastname: Lumeng
mesh_terms: D001741:Black or African American / Q000523:psychology; D019540:Area Under Curve; D015992:Body Mass Index; D017028:Caregivers; D002648:Child; D002675:Child, Preschool; D005260:Female; D006630:Hispanic or Latino / Q000523:psychology; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism*; D008297:Male; D011203:Poverty / Q000523:psychology*; D012463:Saliva / Q000378:metabolism; D013315:Stress, Psychological / Q000378:metabolism* / Q000523:psychology*; D044465:White People / Q000523:psychology
chemical_list: D006854:Hydrocortisone
keywords: BMI; Child; Cortisol; Low-income; Obesity; Stress