Adrenal insufficiency in non-transfusion-dependent α-thalassemia

Abstract

Background: Very few studies about adrenal insufficiency (AI) have been published with regard to non-transfusion-dependent (NTD) thalassemia, and none of those studies involved α-thalassemia patients. The aim of this study was therefore to determine the prevalence of AI in patients with NTD α-thalassemia, and to identify factors that predict the development of AI in this thalassemia subpopulation.

Methods: This cross-sectional descriptive study was conducted in NTD α-thalassemic children at three referral hospitals in Thailand in 2015-2016. Preliminary screening for AI was done using the 1 μg adrenocorticotropic hormone (ACTH) stimulation test. Suspected AI was then confirmed on insulin tolerance test (ITT). AI was defined as peak cortisol <18 μg/dL. AI was categorized as either primary or secondary AI according to peak ACTH.

Results: Thirty patients with NTD α-thalassemia were included in this study. Ten of 25 patients (40%) had abnormal initial screening. Eight of nine (88.9%) who underwent ITT were confirmed as having AI. No patients diagnosed with AI had any clinical symptoms of AI. The percentage of primary and secondary AI (n = 8) was 25% and 75%, respectively. Mean age and mean hemoglobin level showed a trend toward being associated with AI (P = 0.98).

Conclusion: The prevalence of biochemical AI in α-thalassemia patients was similar to rates previously reported for NTD β-thalassemia. Annual screening for AI in α-thalassemia patients is recommended, and glucocorticoid replacement should be considered in NTD α-thalassemia patients with AI during critical illness.

Keywords: adrenal insufficiency; cortisol; hemoglobin-H; non-transfusion-dependent thalassemia; α-thalassemia.