Abstract
Background: Alterations in morning serum cortisol (MSC) have been associated with higher cardiometabolic risk. This finding has been documented primarily in populations with overweight or obesity; however, it has not been clearly established if obesity plays a requisite role in this relationship. This study seeks to extend earlier findings by examining whether body composition measures alter the relationship between MSC with glucose and insulin markers, blood pressure, and lipid parameters in Latino youth in middle adolescence. Methods: This cross-sectional study included 196 healthy adolescents (130F/66M; mean age: 16.4 ± 0.6 years; 95% Latino; mean body mass index, BMI: 24.3 ± 5.7) from Los Angeles, California. Morning cortisol, glucose, insulin, glycated hemoglobin, and lipids (triglycerides and high-density lipoprotein cholesterol) were assessed from a fasting blood sample. Sitting systolic and diastolic blood pressure was averaged from duplicate measures. Body composition measures included BMI and waist circumference, which were used as proxies for total body and abdominal adiposity, respectively. Triplicate measurements of weight and height were averaged for calculation of BMI; age- and sex-specific BMI z-score was used to classify into normal BMI or overweight/obese BMI status. Waist circumference was measured in duplicate and the average was used to classify participants into two strata: normal/healthy waist circumference (<90th percentile for age, sex, and ethnicity) and high waist circumference (≥90th percentile). Results: The primary findings were that higher MSC was associated with higher fasting glucose and systolic blood pressure after adjusting for age, sex, and BMI z-score (and/or waist circumference). BMI status or waist circumference status did not alter these relationships. Main Conclusion: Our results suggest that the relationships between hypothalamic-pituitary-adrenal axis function and certain cardiometabolic risk factors may be independent of adiposity. Future research is warranted to discover the contributors and underlying mechanisms of these relationships in adolescent populations. ClinicalTrials.gov identifier: NCT02088294.