Peak cortisol response to corticotropin-releasing hormone is associated with age and body size in children referred for clinical testing: a retrospective review

Coordination between frontolimbic resting state connectivity and hypothalamic-pituitary-adrenal axis functioning in adolescents with and without depression

Depression is associated with abnormalities in Hypothalamic-Pituitary-Adrenal (HPA) axis functioning and neural circuitry that underlie the stress response. Resting-state functional connectivity (RSFC) between frontolimbic brain regions captures intrinsic connections that may set the stage for the rallying and regulating of the HPA axis system. This study examined the association between cortisol stress response and frontolimbic (amygdala and ventral and dorsal medial prefrontal cortex [vmPFC and dmPFC respectively]) RSFC in 88 (Age: M = 15.95, SD = 2.04; 71.60% female) adolescents with (N = 55) and without (N = 33) major depressive disorder (MDD). We collected salivary cortisol in the context of a modified Trier Social Stress Test (TSST) paradigm. Key findings were that adolescents with depression and healthy controls showed different patterns of association between amygdala and vmPFC RSFC and HPA functioning: while healthy controls showed a positive relationship between frontolimbic connectivity and cortisol levels that may indicate coordination across neural and neuroendocrine systems, adolescents with depression showed a minimal or inverse relationship, suggesting poor coordination of these systems. Results were similar when examining non-suicidal self-injury subgroups within the MDD sample. These findings suggest that the intrinsic quality of this frontolimbic connection may be related to HPA axis functioning. In MDD, inverse associations may represent a compensatory response in one system in response to dysfunction in the other. Longitudinal multilevel research, however, is needed to disentangle how stress system coordination develops in normal and pathological contexts and how these systems recover with treatment.

Evaluating the Low-Dose ACTH Stimulation Test in Children: Ideal Times for Cortisol Measurement

CONTEXT

Central adrenal insufficiency (AI) can be diagnosed with the low-dose ACTH stimulation test (LDST). Protocols determining timing of cortisol sampling vary, with 30 minutes after stimulation being most common.

OBJECTIVES

To determine optimal times to draw cortisol levels and factors predicting timing of peak cortisol levels in children undergoing LDST.

DESIGN

Retrospective chart review of LDSTs between February 2014 and September 2017.

SETTING

The Children's Hospital of Eastern Ontario.

PATIENTS

Patients 3 months to 20 years who underwent LDSTs.

INTERVENTION

LDSTs were performed with cortisol levels at 0, 15, 30, and 60 minutes after 1 μg cosyntropin. Cortisol values <18 μg/dL (500 nmol/L) determined AI.

MAIN OUTCOME MEASURES

The incremental value of testing cortisol at 15 or 60 minutes, in addition to the standard 30-minute sample, was estimated.

RESULTS

A total of 221 patients met inclusion criteria. The mean age was 9.7 years, and 32% were female. Peak cortisol levels were 19%, 67%, and 14% at 15, 30, and 60 minutes, respectively. One false positive LDST result would be prevented for every 24 (95% CI, 13 to 46) or 55 (95% CI, 22 to 141) patients tested at 15 or 60 minutes in addition to the standard 30-minute test. Of the 122 patients who passed the LDST, discontinuing the 15- and 60-minute samples would have misdiagnosed 12 patients (9.8%). Glucocorticoid exposure, age, and body mass index z scores were independent predictors of peak cortisol timing.

CONCLUSION

Although the majority of patients peak 30 minutes after cosyntropin administration, testing cortisol levels at 15 and 60 minutes reduces the risk of false positive LDSTs.