Circadian pattern of circulating plasma ACTH, cortisol, and aldosterone in patients with beta-thalassemia

The Frequency of Adrenal Insufficiency in Adolescents and Young Adults with Thalassemia Major versus Thalassemia Intermedia in Iran

BACKGROUND

Endocrine dysfunction is not uncommon complication in patients with transfusion-dependent thalassemia and is thought to occur as a consequence of excessive iron overload. The primary objective of this study is to determine the frequency of adrenal insufficiency in patients with thalassemia major and thalassemia intermediate.

METHODS

This cross-sectional study was done at the Shiraz University of Medical Sciences, Shiraz, Southern Iran, in 2013. One hundred and ninety patients were divided into two groups; thalassemia major(TM) and thalassemia intermediate (TI) groups. We measured 8 AM serum cortisol, ACTH and ferritin concentrations in all patients.

RESULTS

The mean age of the TM and TI group were 22.5±5.7 and 23.8±6 years, respectively. 90 patients (47.4%) were splenectomized, 34 (36.2%) with TM and 56 (58.2%) with TI (p :<0.001). The median and interquartile range of serum ferritin levels were 2184±3700 ng/ml and 437±443ng/ml in TM and TI respectively (p< 0.001). Three patients with TM (1.6%) had low basal cortisol and ACTH levels. However, their cortisol response to ACTH stimulation was normal.

CONCLUSIONS

Low basal concentrations of cortisol and ACTH occurred in 1.6% of our adolescents young adult patients with TM suggesting a central defect in cortisol secretion at the basal state. However, cortisol response to standard - dose ACTH was normal in all patients with TM and TI.

Cortisol response to low dose versus standard dose (back-to-back) adrenocorticotrophic stimulation tests in children and young adults with thalassemia major

BACKGROUND

Thalassemia major patients with repeated blood transfusion have high prevalence of endocrinopathies due to iron overload.

MATERIALS AND METHODS

We examined the adrenocortical function in 23 thalassemic patients (10 children and 13 young adults) aged 8-26 years. Serum cortisol and dehydroepiandrosterone sulfate (DHEA-S) concentrations were determined in each subject before blood transfusion both in basal condition and after low dose (LD) (1 μg), followed by standard dose (SD) (250 μg, respectively) with synthetic corticotrophin beta 1-24 ACTH (Synacthen, Ciba). Normal controls were a group of 13 age- and sex-matched normal subjects.

RESULTS

Using a peak total cortisol cutoff level of 550 nmol/L and increments of 200 μg above basal cortisol, adrenal insufficiency (AI) was demonstrated in 8 patients (34.7%) after the LD ACTH and in 2 patients (8.7%) after SD cosyntropin (ACTH) test, but none of the controls. Using a peak total cortisol cutoff level of 420 nmol/L and increments of 200 μg above basal cortisol, AI was demonstrated in 5 patients (21.7%) after the LD ACTH and in 2 patients after SD ACTH test (8.7%), but none of controls. All patients with biochemical AI were asymptomatic with normal serum sodium and potassium concentrations and had no history suggestive of adrenal pathology. The peak cortisol concentrations in thalassemic patients with impaired adrenal function both after 1 μg and 250 μg cosyntropin (294 ± 51 nmol/L and 307 ± 58.6) were significantly lower than those with patients with normal (454 ± 79.7 nmol/L and 546.1 ± 92.2 nmol/L, respectively) and controls (460.2 ± 133.4 nmol/L and 554.3 ± 165.8 nmol/L, respectively). Adolescents and young adults, but not children with thalassaemia, had significantly lower peak cortisol concentration after SD ACTH versus controls. Peak cortisol response to LD ACTH was correlated significantly with peak cortisol response to SD in all patients (r = 0.83, P < 0.0001). In adolescents and young adults with thalassemia, DHEA-S levels before and after LD ACTH stimulation were significantly lower and the cortisol/DHEA-S ratios were significantly higher than the controls.

CONCLUSION

The use of LD ACTH test diagnoses more adrenal abnormalities versus SD ACTH in thalassemic patients. The relatively high prevalence of AI in thalassemic adolescents and young adults necessitates that these patients have to be investigated for AI before major surgery and those with impaired cortisol secretion should receive stress doses of corticosteroids during the stressful event.

Growth and endocrine disorders in thalassemia: The international network on endocrine complications in thalassemia (I-CET) position statement and guidelines

The current management of thalassemia includes regular transfusion programs and chelation therapy. It is important that physicians be aware that endocrine abnormalities frequently develop mainly in those patients with significant iron overload due to poor compliance to treatment, particularly after the age of 10 years. Since the quality of life of thalassemia patients is a fundamental aim, it is vital to monitor carefully their growth and pubertal development in order to detect abnormalities and to initiate appropriate and early treatment. Abnormalities should be identified and treatment initiated in consultation with a pediatric or an adult endocrinologist and managed accordingly. Appropriate management shall put in consideration many factors such as age, severity of iron overload, presence of chronic liver disease, thrombophilia status, and the presence of psychological problems. All these issues must be discussed by the physician in charge of the patient's care, the endocrinologist and the patient himself. Because any progress in research in the field of early diagnosis and management of growth disorders and endocrine complications in thalassemia should be passed on to and applied adequately to all those suffering from the disease, on the 8 May 2009 in Ferrara, the International Network on Endocrine Complications in Thalassemia (I-CET) was founded in order to transmit the latest information on these disorders to the treating physicians. The I-CET position statement outlined in this document applies to patients with transfusion-dependent thalassemia major to help physicians to anticipate, diagnose, and manage these complications properly.

High prevalence of "biochemical" adrenal insufficiency in thalassemics: is it a matter of different testings or decreased cortisol binding globulin?

CONTEXT

High prevalence of "biochemical" adrenal insufficiency (AI) in thalassemics has been reported. However, "clinical" AI is rare.

AIM

The aim was to determine whether cortisol binding globulin (CBG) or tests used in assessing adrenal function contributed to the abnormally high prevalence of biochemical AI.

SETTING

The study was conducted at Ramathibodi Hospital, Mahidol University, Bangkok, Thailand.

PARTICIPANTS

Participants included 56 children and adolescents with thalassemia and 44 controls.

MAIN OUTCOME MEASURES

Serum CBG and adrenal function test results assessed by 1 μg cosyntropin test and insulin tolerance test (ITT) were measured. Free cortisol index (FCI) calculated by total cortisol (TC)/CBG and calculated free cortisol (cFC) were determined.

RESULTS

Mean (sd) CBG levels were comparable between patients and controls [45.2 (11.0) vs. 47.0 (8.6) mg/liter]. Peak TC, FCI, and cFC after cosyntropin test were lower in thalassemics [TC, 15.2 (4.0) vs. 18.9 (3.1) μg/dl; FCI, 3.4 (0.8) vs. 4.2 (1.2) μg/mg, P <0.001; and cFC, 1.03 (0.38) vs. 1.44 (0.61) μg/dl, P = 0.008]. Thirty of 56 thalassemics (53.6%) had AI, defined as having peak TC of less than 16 μg/dl. ITT was performed in 26 of those 30 patients. Five of 26 patients had peak TC after an ITT of at least 20 μg/dl. As a result, the estimated frequency of AI in the entire patient group was reduced by approximately 10%.

CONCLUSION

The 1 μg cosyntropin test could be an adrenal function screening test in thalassemics. However, for definite diagnosis, ITT should be performed in those having peak total cortisol of less than 16 μg/dl after the 1 μg cosyntropin test.

Endocrine complications of thalassemia

Growth, sexual development, fertility, bone mineral density, diabetes mellitus, hypothyroidism, hypoparathyroidism, and hypoadrenalism are the main issues to be addressed in the long-term follow-up of patients with thalassemia. During childhood, growth may be affected by anemia, and other potential endocrine complications. Puberty is the stage of the maximal growth insult. Beta thalassemia is associated with bone abnormalities characterized by bone marrow expansion of the medullary cavity, and osteopenia with cortical thickening and trabecular coarsening. Good nutrition with adequate vitamins and trace elements intake, along with calcium and vitamin D supplementation, can increase bone density and prevent bone loss. Endocrine abnormalities should be monitored carefully and a thorough endocrine evaluation should be carried out yearly in every patients to detect subclinical endocrinopaties.