Acquired Hypogonadotropic Hypogonadism (AHH) in Thalassaemia Major Patients: An Underdiagnosed Condition?

INTRODUCTION

In males, acquired hypogonadotropic hypogonadism (AHH) includes all disorders that damage or alter the function of gonadotropin-releasing hormone (GnRH) neurons and/or pituitary gonadotroph cells. The clinical characteristics of AHH are androgen deficiency and lack, delay or halt of pubertal sexual maturation. AHH lead to decreased libido, impaired erectile function, and strength, a worsened sense of well-being and degraded quality of life (QOL).

PATIENTS AND METHODS

We studied 11 adult men with thalassemia major (TM) aged between 26 to 54 years (mean ± SD: 34.3 ± 8.8 years) with AHH. Twelve age- and sex-matched TM patients with normal pubertal development were used as a control group. All patients were on regular transfusions and iron chelation therapy. Fasting venous blood samples were collected two weeks after transfusion to measure serum concentrations of IGF-1, free thyroxine (FT4), thyrotropin (TSH), cortisol, luteinizing hormone (LH), follicle stimulating hormone (FSH), total testosterone (TT), prolactin and estradiol (E2), glucose, urea, creatinine and electrolytes (including calcium and phosphate). Liver functions and screening for hepatitis C virus seropositivity (HCVab and HCV-RNA) were performed. Iron status was assessed by measuring serum ferritin levels, and evaluation of iron concentrations in the liver (LIC) and heart using MRI- T2*. Bone mineral density was measured at the lumbar spine (L1-L4) for all patients with AHH by dual energy X-ray absorptiometry (DXA) using Hologic QDR 4000 machine.

RESULTS

The mean basal serum LH and FSH concentrations in AHH patients were 2.4 ± 2.2 IU/L and 1.2 ± 0.9 IU/L respectively; these, values were significantly lower compared to the control group. Semen analysis in 5 patients with AHH showed azoospermia in 3 and oligoasthenozoospermia in 2. The percentage of patients with serum ferritin level >2000 ng/ml (severe iron load) was significantly higher in AHH patients compared to controls, 5/11 (45.4 %) versus1/12 (8.3%), p=0.043. Heart iron concentrations (T2* values) were significantly lower in AHH patients compared to controls (p=0.004). Magnetic resonance imaging in the 3 azoospermic patients revealed volume loss and reduction of pituitary signal intensity. Heart T2* values were significantly reduced in the AHH group vs. the controls (p=0.004). On the other hand, liver iron concentration (mg/g dry weight) was not different between the two groups of TM patients. Using DXA, 63.6 % (7/11) of patients with AHH were osteoporotic, and 36.3 % (4/11) were osteopenic.

CONCLUSIONS

In this cohort of thalassemic patients iron overload and chronic liver disease appear to play a role in the development of AHH. Treatment of AHH in TM patients is a vital and dynamic field for improving their health and QOL. Early identification and management of AHH are very crucial to avoid long-term morbidity, including sexual dysfunction and infertility. Therapy aims to restore serum testosterone levels to the mid-normal range. Many exciting opportunities remain for further research and therapeutic development.