Hair steroid concentration before and after the beginning of the COVID-19 pandemic in preschoolers: the moderating effect of family characteristics

Background : Persistent changes in stress physiological systems are hypothesized to jeopardize health, especially at a younger age. COVID-19 has been perceived as stressful, namely because of the changes in daily routine and social isolation. However, whether the pandemic was accompanied by changes in stress-biomarkers remains to be explored as perceived and biological stress poorly correlate. Further, some children may display more changes in stress-biomarkers according to their family environment. This study examined if preschoolers had increased hair steroid concentrations following the COVID-19 pandemic onset and whether family-level factors may have exacerbated or buffered this change.

Methods : 136 preschoolers (2-4 years) provided hair for steroid measurement (cortisol [HCC], dehydroepiandrosterone [DHEA], cortisone [HCNC], HCC-HCNC-ratio, HCC-DHEA-ratio) in November 2019-T0 and in June 2020-T1. Measures of family conflict resolution and lack of cohesion, as well as parents’ COVID-19 stress were collected using questionnaires completed by parents at T1. Family income was reported at T0. Linear mixed models for repeated measures were used.

Results : While no biological change was observed from before to after the COVID-19 pandemic onset for any hair steroid, a moderation effect of family income was noted for HCC-HCNC-ratio, suggesting a deregulation of dynamic processes leading to higher stress for children from higher income families. DHEA was also higher for boys and lower for higher income families.

Conclusion : Our study provides limited evidence that the first months of COVID-19 pandemic, an unpredictable and potentially threatening event, were associated with persistent changes in stress-biomarkers in preschoolers.