Avaliação da recuperação do eixo hipotalâmico-hipofisário-adrenal após corticoterapia por meio do cortisol basal

Abstract

The glucocorticoid-induced inhibition that occurs after discontinuation of treatment is the most frequent cause of adrenal insufficiency. There are yet some doubts about the best way of evaluating the hypothalamic-pituitary-adrenal (HPA) axis in those patients. The main objective of this study was to evaluate the utility of basal cortisol in diagnosing adrenal insufficiency. Thirty-five children with acute lymphoid leukemia (ALL) receiving glucocorticoid therapy (median age of 6.9 years) were evaluated. A stimulus test with corticotropin releasing hormone (CRH-1 mcg/kg) was performed before the introduction of dexamethasone (6 mg/m2/day, for 28 days), in the 8th and the 28th days of glucocorticoid therapy, and 48 hours and one month after discontinuation of therapy. Suppression of the basal secretion as well as the maximum concentration of cortisol (post-CRH) occurred during glucocorticoid therapy, which persisted for 48 hours after the steroid was removed from treatment (p< 0.01 and p< 0.0001, respectively, for the three tests). One month after ceasing the administration of the glucocorticoid, the basal secretion, as well as the maximum concentration of cortisol, were similar to that before glucocorticoid therapy. There was a positive and statistically significant correlation between basal secretion and maximum concentration of cortisol in all tests. We observed 95% of specificity for the diagnosis of adrenal insufficiency when the inferior limit of basal cortisol was 8.5 mcg/dl. According to these results we concluded that basal secretion of cortisol is a good marker of supra-renal function in evaluating children after discontinuation of glucocorticoid therapy.

Diagnostic Accuracy of Morning Salivary Cortisol in the Assessment of the Hypothalamic-Pituitary-Adrenal Axis Recovery after Prolonged Corticosteroid Therapy in Children

“…Morning serum cortisol has a high diagnostic accuracy at the extremes of normality (<3 μg/dL or >20.0 μg/dL) [21], whereas intermediate values seem to be less useful, probably due to the lack of adequate sensitivity of non-stimulated measurements for the diagnosis of AI. Prete and Bancos [3] have shown that a morning serum cortisol >350 nmol/L (12.7 μg/dL) rules out secondary AI with high diagnostic efficiency, allowing glucocorticoid therapy to be safely discontinued.…”

“…However, some conflict arises with serum cortisol concentrations between 82.8 and 275.9 nmol/L (3.0–10 μg/dL) [1, 3]. Silva et al [21] found that a baseline serum cortisol level above 234.5 nmol/L (8.5 μg/dL) by the RIA method on day 30 after glucocorticoid withdrawal had a specificity of 86% for HPA recovery. In the present study, we used our local cut-off value of ≥193 nmol/L (7.0 μg/dL) to define adequate morning cortisol secretion.…”

Corticosteroid‐associated hypothalamic–pituitary–adrenal axis suppression in brain tumours: a focus on dosing and tapering

“…They have limited sensitivity and specificity for diagnosing SAI and evaluating HPA axis integrity, but they can be performed to identify the baseline level before administrating the stimulus in stimulation tests. 24 However, several measurement tests involve stimulation of the component of the HPA axis and are considered clinically challenging and provide objective data to evaluate the recovery of HPA axis integrity. It should be analysed and interpreted by healthcare professionals due to the difficulty of correlating the biochemical abnormalities with clinical features.…”

Retirada da corticoterapia: recomendações para a prática clínica

“…Tests not involving stimulation, such as measurement of 32 It is important that cortisol assays (baseline or post-stimulation) be carried out after suspension of corticosteroid therapy, or at least 24 to 48 hours after the last dose, since, with the exception of dexamethasone, the other corticosteroids interfere with the results. 6,39 Measurement of free cortisol in saliva, a noninvasive and easy to obtain method, has not yet been validated for assessing the HPA axis, due to technical difficulties with the tests and due to the need to control variables that interfere with results (for example, nutritional intake, medications).…”