Obesity and Hair Cortisol: Relationships Varied Between Low-Income Preschoolers and Mothers

Abstract

Literature on the relationship between hair cortisol concentration (HCC) and body mass index (BMI) is scarce and inconsistent in both preschoolers and parents. Thus, the study aimed to examine the relationships among HCC, perceived distress, coping, and BMI among low-income Head Start preschoolers and mothers. A cross-sectional, correlational study was conducted with a non-random sample of 35 mother-preschooler dyads. Height and weight were measured using a ShorrBoard Stadiometer and a Seca portable electronic scale, respectively. HCC was extracted using the enzyme immunoassay approach. Mothers' perceived distress and coping were assessed by Cohen's Perceived Stress Scale. Mothers' mean age was 29.74years, and preschoolers' mean age was 4.69years. The sample included 17% Hispanic, 54% Black, and 60% single mothers; and 23% Hispanic and 60% Black preschoolers. Compared to mothers in low HCC group (< 4.1pg/mg), mothers in high HCC group (≥ 4.1pg/mg) had lower BMI (B = - 4.62, p = .049). The indirect effects of mothers' HCC on BMI via perceived distress and coping was 15% of the total effects. Preschoolers with mothers in high HCC group had significantly lower BMI z-score than those with mothers in low HCC group (B = - 0.94, p = .043). Preschoolers' HCC had a small positive correlation with their BMI z-score (B = 0.01, p = .112). Relationships between HCC and BMI varied between low-income mothers and preschoolers. A stress management component may need to be integrated into future obesity interventions. Given the limitation of small sample size and cross-sectional study design, the findings need to be interpreted with caution, and further investigation is warranted.