Salivary Cortisol Does Not Correlate with Metabolic Syndrome Markers or Subjective Stress in Overweight Children

The Relationship between Psychological Stress and Anthropometric, Biological Outcomes: A Systematic Review

Background and Objectives: Challenges and threats to global security and the growing demands of today's society lead to significantly increased exposure to stress. Stress can negatively affect numerous physiological processes, including metabolic changes. An unhealthy lifestyle might intensify this disruption. The aim of the systematic review was to establish the effect of psychological stress on metabolic and anthropometric factors in healthy individuals. Materials and Methods: The study was conducted according to the PRISMA guidelines; and the risk of bias (ROB) assessment was based on the Newcastle-Ottawa Scale (NOS). A literature search of the MEDLINE/PubMed database was conducted using specific search terms. Results: We identified 32 articles meeting the inclusion criteria for the review with the different experimental designs and aims. Most of the papers were at high ROB. The included studies were conducted in groups of adults and children/teenagers. The most-often-applied tool to measure stress severity was the Perceived Stress Scale (PSS). Twenty-two studies analyzed the connection between stress and body composition, and bioimpedance analysis (BIA) was the most often used method. For biological parameters, the most frequently analyzed was cortisol (n = 9). The other examined factors included glucose, insulin, parameters related to food intake regulation, carbohydrates, lipid metabolism, inflammation, and oxidative stress. The included studies were incompliance in relation to the assessment method and type of assessed biological fluids. Conclusions: The vast majority of studies do not support the effect of chronic distress on anthropometric measurements and biological markers levels. However, many of them suggest adverse, synergistic effects of unhealthy lifestyle patterns and the stress on the examined variables. Further experiments should implement a similar and repeatable methodology.

Circadian Rhythm of Salivary Cortisol in Obese Adolescents With and Without Apnea: A Pilot Study

BACKGROUND AND OBJECTIVE

Obstructive sleep apnea (OSA) and obesity are associated with stress system activation involving the hypothalamic-pituitary-adrenal (HPA) axis in adults, but these effects in childhood and adolescence remain unclear. We examined diurnal salivary cortisol as a measurement of the HPA axis function in obese adolescents with and without OSA and the relationships between cortisol levels, body weight, and parameters of polysomnography (PSG).

METHODS

After PSG, saliva samples were collected from obese participants (with and without OSA) and lean participants four times over a 24-h period, namely, at 7:00 h (m-sCort), 13:00 h (a-sCort), 19:00 h (e-sCort), and 23:00 h (n-sCort). An enzyme-linked immunosorbent assay (ELISA) was used to measure salivary cortisol levels. The mean values of cortisol levels and fixed-time point diurnal cortisol slope (DCS) were calculated and compared among the three study groups. Correlations between parameters were analyzed using Spearman's correlation coefficients.

RESULTS

Obese OSA participants had significantly higher e-sCort and n-sCort levels than both obese non-OSA participants and lean controls. However, m-sCort and a-sCort in these patients had a pronounced upward trend. M-sCort was significantly correlated with both the lowest oxygen saturation (SpO₂) and time with SpO₂ <90%. Moreover, in the obese OSA group, DCS was significantly flatter than in the other two groups. The a-sCort in obese non-OSA participants was significantly higher than that in the lean control group and, surprisingly, was positively correlated with the apnea/hypopnea index. Additionally, m-sCort was related to body weight.

CONCLUSION

This study provided further evidence for alterations in diurnal cortisol production in obese adolescents, which may indicate a chronically stressed HPA axis. However, there were significant differences in salivary cortisol parameters between participants with and without OSA. Furthermore, patients with OSA had more associations between time-point cortisol levels and OSA-related indices. Nonetheless, this research is a pilot study, and further investigations are necessary.

Associations of Hair Cortisol Concentrations With Cardiometabolic Risk Factors in Childhood

CONTEXT

Biological stress is related to cardiovascular disease in adults. The associations of stress with cardiovascular and metabolic diseases may originate in childhood.

OBJECTIVE

This work aims to examine the associations of hair cortisol concentrations at age 6 years with cardiometabolic risk factors at ages 6 and 10 years.

METHODS

Cortisol concentrations were measured in hair of 6-year-old children (n = 2598) participating in the Generation R Study, a population-based prospective cohort study in Rotterdam, the Netherlands. Main outcome measures included blood pressure, heart rate, concentrations of insulin, glucose, lipids, and C-reactive protein in blood at ages 6 and 10 years.

RESULTS

Higher hair cortisol concentrations at age 6 years were associated with higher systolic blood pressure at age 10 years (difference 0.17 SD score; 95% CI, 0.03-0.31). The association attenuated into nonsignificance after adjustment for childhood body mass index (BMI) at age 6 years. Higher hair cortisol concentrations at age 6 years were associated with an increase in total and low-density lipoprotein cholesterol between ages 6 and 10 years but not with those measurements at age 6 or 10 years. Hair cortisol concentrations were not associated with other cardiometabolic risk factors at age 6 or 10 years.

CONCLUSION

Hair cortisol concentrations were not independent of BMI associated with cardiometabolic risk factors at 6 or 10 years. The associations of biological stress with cardiometabolic risk factors may develop at later ages.

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OBJECTIVE:

To examine associations of hair cortisol concentration (HCC) in mid-childhood and change in HCC from mid-childhood to early adolescence (ΔHCC) with early adolescent adiposity and cardiometabolic biomarker measures.

METHODS:

In Project Viva, a pre-birth cohort of mothers and children, we measured HCC in 599 white children in mid-childhood and in 426 of these participants in early adolescence. We used multivariable linear regression to examine associations of mid-childhood HCC and ΔHCC with BMI-for-age-and-sex z-score, waist circumference, waist-height ratio, dual X-ray absorptiometry total and trunk fat mass, a metabolic risk z-score, adiponectin, HOMA-IR, high-density lipoprotein, C-reactive protein, interleukin-6, leptin, and systolic blood pressure.

RESULTS:

Over a mean (SD) follow-up of 5.2 (0.8) years, we did not find associations of mid-childhood HCC with BMI-for-age-and-sex z-score (β=0.00 per 1-interquartile range of HCC, 95% confidence interval [CI]: −0.08, 0.07), waist circumference (β=−0.04cm, 95% CI: −0.83, 0.74), metabolic risk z-score (β=0.04, 95% CI: −0.03, 0.11), or other cardiometabolic measures except for an increase in log-transformed HOMA-IR (β=0.10, 95% CI: 0.04, 0.17). ΔHCC was not associated with any outcome measures.

CONCLUSIONS:

We found that mid-childhood HCC was not associated with early adolescent adiposity or cardiometabolic biomarkers except for a slight increase in HOMA-IR.

Prenatal and childhood predictors of hair cortisol concentration in mid-childhood and early adolescence

Background

Hair cortisol concentration (HCC) is an increasingly used measure of systemic cortisol concentration. However, determinants of HCC in children and adolescents are unclear because few prospective studies have been conducted to date.

Study design

We followed 725 children in Project Viva, a pre-birth cohort study of mothers and children, who provided hair samples at mid-childhood (median age: 7.7 years) or early adolescence (median age: 12.9 years). We examined associations of various factors measured from pregnancy to mid-childhood with HCC in mid-childhood and early adolescence, as well as change in HCC between these time points (ΔHCC).

Results

There were 426 children with HCC measurements in both mid-childhood and early adolescence, 173 children with measures only in mid-childhood, and 126 with measures only in early adolescence. HCC was lower in mid-childhood (median 1.0pg/mg [interquartile range, IQR: 0.5, 2.4]) than early adolescence (2.2pg/mg [1.1, 4.4]). In multivariable-adjusted regression models, female sex (β = -0.41, 95% CI: -0.67, -0.15) and birth weight-for-gestational age z-score (β = -0.19, 95% CI: -0.33, -0.04) were associated with lower mid-childhood HCC, while prenatal smoking was associated with higher mid-childhood HCC (β = 0.53, 95% CI: 0.04, 1.01). In early adolescence, child age (β = 0.34 per year, 95% CI: 0.21, 0.46) female sex (β = 0.33, 95% CI: 0.10, 0.57), and maternal pre-pregnancy body mass index (β = 0.15 per 5-kg/m², 95% CI: 0.01, 0.29) were positively associated with HCC. Child anthropometric measures and biomarker concentrations were not associated with HCC.

Conclusion

Maternal pre-pregnancy BMI, maternal prenatal smoking, and low birth weight were associated with higher mid-childhood and adolescent HCC. However, few postnatal characteristics were associated with HCC.