The Role of Morning Basal Serum Cortisol in Assessment of Hypothalamic Pituitary-Adrenal Axis

Abstract

Purpose: e use of morning basal serum cortisol levels as an alternative to dynamic testing for assessment of hypothalamic-pituitary-adrenal (HPA) axis has previously been reported. e purpose of this study was to determine the lower and upper cuto values that would obviate subsequent HPA axis testing.Methods: A single-centre, retrospective study from a tertiary care endocrinology clinic was conducted, analyzing data from 106 adult individuals referred for HPA axis testing who had undergone a 0800-0900 morning basal serum cortisol test followed by a standard dose (250 μg) adrenocorticotropin (ACTH) stimulation test.e ability of morning basal serum cortisol values to predict post-ACTH 30 or 60 minute peak cortisol value of >500 or >550 nmol/L was investigated.Results: A morning basal cuto of <128 nmol/L is su cient for predicting a post-ACTH value < 550 nmol/L, and morning basal cuto levels of >243 nmol/L and >266 nmol/L predict peak post-ACTH values of >500 and >550 nmol/L respectively, obviating the need for dynamic testing. Regression analysis further demonstrated the log-linear relationship between morning basal and peak levels, while also nding a signi cant decrease in peak post-ACTH levels for patients diagnosed with secondary hypothyroidism (76 nmol/ L lower, p=0.003) or secondary hypogonadism (61 nmol/L lower, p=0.02). ese data suggest that the risk of cortisol de ciency is signi cantly higher in individuals with additional pituitary insu ciencies. e odds ratios for cortisol de ciency in patients with history of isolated secondary hypothyroidism was 3.41 (p=0.015), with isolated secondary hypogonadism was 4.77 (p=0.002) and with both was 7.45 (p=0.0002). Conclusion:Morning basal serum cortisol levels show promise as an e ective screening test for HPA insu ciency for most patients. Clinicians should consider the high probability of HPA insu ciency in patients with one or more pituitary insu ciencies.

Analysis and natural history of pituitary incidentalomas

“…PI without clinical and biochemical evidence of hormonal over-secretion despite positive immunohistochemistry staining were regarded as clinically silent and were categorized as NFT. Secondary hormone insufficiency was defined as follows: adrenal insufficiency was defined as either basal serum cortisol of <130 nmol/L or failure of serum cortisol to rise ≥500 nmol/L after an insulin tolerance test or 250 μg ACTH stimulation test based on our previously published data (11). Secondary hypothyroidism diagnosis was based on low fT4 with inappropriate normal or low TSH.…”

Recovery of adrenal function after chronic secondary adrenal insufficiency in patients with hypopituitarism

“…Based on our previously published data, 7 we performed a basal serum cortisol measurement on all pituitary patients at 09Á00 h and if the serum cortisol was <130 nM (in the absence of an interfering medication or other confounding factors such as shift workers), a diagnosis of SAI was made, whereas a serum cortisol of >250 nM (9 lg/dl) was regarded as normal HPA axis function. 7,8 Those patients with a basal serum cortisol of 130-250 nM underwent either an ACTH test or an ITT; the choice of the test was at the discretion of the clinician. Based on previously published studies, 9-11 a 30-min post-ACTH injection cortisol value of <500 nM, or a peak cortisol value of less than 500 nM following insulin-induced hypoglycaemia (glucose <2Á2 nM or 40 mg/dl) was regarded as SAI.…”

Increased Cortisol Levels in Depression: A Comparative Study Evaluating the Correlation of Hypercortisolemia with Prosocial Coping Mechanisms

“…In the current research the morning serum cortisol was measured, due to lack of availability of alternative methods. In the last years cortisol level from saliva was used to determine the cortisol awaking response (CAR), but the use of morning basal serum cortisol levels as an alternative to dynamic testing for assessment of hypothalamic-pituitary-adrenal axis has previously been reported [ 23].Serum basal cortisol levels may be used as the first-line test in the assessment of thehypothalamic-pituitary-adrenal axis both preoperatively and postoperatively [24].…”