Blunted circadian cortisol in children is associated with poor cardiovascular health and may reflect circadian misalignment

• Published in: Psychoneuroendocrinology Vol. 129; p. 105252
• Main Authors: Dai, Weiying, Wagh, Swanand A., Chettiar, Steffi, Zhou, Grace D., Roy, Runia, Qiao, Xingye, Visich, Paul S., Hoffman, Eric P.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-07-2021
• Subjects: Blood pressure; Cardiovascular Diseases - epidemiology; Child; Circadian rhythm; Circadian Rhythm - physiology; Cortisol; Cross-Sectional Studies; Fasting; Heart Disease Risk Factors; Humans; Hydrocortisone - metabolism; Longitudinal Studies; Metabolic syndrome; Saliva - chemistry; SES; FIML; SRMR; CFI; dL; Cortisol; Circadian rhythm; Metabolic syndrome; BP; HDL; CHIP; RMSEA; TG; LDL; LTC; SEM; Blood pressure; BMI; CFA
• ISSN: 0306-4530; 1873-3360
• DOI: 10.1016/j.psyneuen.2021.105252

Circadian cues in children (sunlight, exercise, diet patterns) may be associated with health outcomes. The primary objective was to assess associations of daily cortisol fluctuations (morning, night) with cardiovascular health outcomes. A secondary objective was to determine if 1-year longitudinal changes in circadian cortisol levels are associated with longitudinal changes in health outcomes.
The Cardiovascular Health Intervention Program (CHIP) was a cross-sectional and longitudinal study of cardiovascular risk profiles in public elementary school children in Southern Maine. Participants were 689 students in 4th grade (baseline; age = 9.20 ± 0.41 years), and 647 students in 5th grade (age = 10.53 ± 0.52 years). Longitudinal data (4th and 5th grade) was available for 347 participants. Clinical outcomes were blood pressure, hip/waist ratios, body mass index, percent fat. Laboratory measures were fasting glucose, lipids, and salivary cortisol measures (morning and evening).
Lower first-in-morning diurnal cortisol levels were associated with increased blood pressure (β −0.23 ± 0.05; p < 0.001), increased body fat (β −0.22 ± 0.05; p < 0.001), and poor lipid profiles (β −0.15 ± 0.07; p < 0.05). Inclusion of night cortisol in the model (stress-related) improved associations of the model with bodyfat composition (morning β −0.27 ± 0.05; p < 0.001; night β +0.16 ± 0.06; p < 0.01). Adjustments for potential confounding variables improved associations of morning cortisol with lipids (β −0.19 ± 0.07; p < 0.01). Longitudinal analysis showed that lower morning diurnal cortisol in 4th grade was associated with increases in blood pressure a year later (β −0.18 ± 0.08; p = 0.017) after adjusting for confounding variables.
Data presented suggest adding circadian misalignment (lower amplitude of first-in-morning cortisol) to existing models of metabolic syndrome in children. Further, circadian misalignment may be a factor contributing to high blood pressure.
•First-in-morning cortisol measures of children may serve as a surrogate biomarker for circadian alignment.•Blunted morning cortisol is suggestive of circadian misalignment.•689 4th grade (~9 yrs) and 647 5th grade (~10 yrs) students were tested for both morning and night saliva cortisol.•Blunted morning cortisol was found associated with cardiovascular risk factors, particularly blood pressure.•Findings suggest that circadian misalignment in children is associated with increased cardiovascular risk factors.