Silva Ivani N, Cunha Cristiane F, Finch Francisca L, Colosimo Enrico A
Divisão de Endocrinologia Infantil e do Adolescente, Departamento de Pediatria, Faculdade de Medicina, Hospital das Clínicas, UFMG, Belo Horizonte, MG.
Arq Bras Endocrinol Metabol. 2006 Feb;50(1):118-24. doi: 10.1590/s0004-27302006000100017. Epub 2006 Apr 17.
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.
治疗中断后发生的糖皮质激素诱导的抑制是肾上腺功能不全最常见的原因。对于评估这些患者下丘脑-垂体-肾上腺（HPA）轴的最佳方法仍存在一些疑问。本研究的主要目的是评估基础皮质醇在诊断肾上腺功能不全中的效用。对35名接受糖皮质激素治疗的急性淋巴细胞白血病（ALL）儿童（中位年龄6.9岁）进行了评估。在引入地塞米松（6mg/m²/天，共28天）之前、糖皮质激素治疗的第8天和第28天以及治疗中断后48小时和1个月时，进行促肾上腺皮质激素释放激素（CRH-1μg/kg）刺激试验。在糖皮质激素治疗期间，基础分泌以及皮质醇的最大浓度（CRH后）受到抑制，在停用类固醇后持续48小时（三项试验分别为p<0.01和p<0.0001）。停用糖皮质激素1个月后，基础分泌以及皮质醇的最大浓度与糖皮质激素治疗前相似。在所有试验中，基础分泌与皮质醇的最大浓度之间存在正相关且具有统计学意义。当基础皮质醇下限为8.5μg/dl时，我们观察到诊断肾上腺功能不全的特异性为95%。根据这些结果，我们得出结论，在评估停用糖皮质激素治疗后的儿童时，皮质醇的基础分泌是肾上腺功能的良好指标。
