Male sickle cell patients, compensated transpubertal hypogonadism and normal final growth

Endocrinopathies in Hemoglobinopathies: What Is the Role of Iron?

Hemoglobinopathies, including β-thalassemia and sickle cell disease (SCD), are common genetic blood disorders. Endocrine disorders are frequent manifestations of organ damage observed mainly in patients with β-thalassemia and rarely in SCD. Iron overload, oxidative stress-induced cellular damage, chronic anemia, and HCV infection contribute to the development of endocrinopathies in β-thalassemia. The above factors, combined with vaso-occlusive events and microcirculation defects, are crucial for endocrine dysfunction in SCD patients. These endocrinopathies include diabetes mellitus, hypothyroidism, parathyroid dysfunction, gonadal and growth failure, osteoporosis, and adrenal insufficiency, affecting the quality of life of these patients. Thus, we aim to provide current knowledge and data about the epidemiology, pathogenesis, diagnosis, and management of endocrine disorders in β-thalassemia and SCD. We conducted a comprehensive review of the literature and examined the available data, mostly using the PubMed and Medline search engines for original articles. In the era of precision medicine, more studies investigating the potential role of genetic modifiers in the development of endocrinopathies in hemoglobinopathies are essential.

Growth Hormone/Insulin-Like Growth Factor 1 Axis Associated with Modifiers Factors in Children with Sickle Cell Anemia

BACKGROUND

Sickle cell anemia is a disease that develops episodes of acute pain and multiple organ dysfunction that can affect the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis. The severity of sickle cell anemia is influenced by modifying factors, such as levels of fetal hemoglobin (HbF), the co-inheritance of alpha-thalassemia, or treatment with hydroxyurea.

METHODS

This cross-sectional study in children with sickle cell anemia evaluated bone age (BA), adult height prediction (AHP) using BA, a target height (TH) calculated as the mean SDS of the parents, and laboratory parameters. Children were grouped according to serum levels of HbF, co-inheritance of alpha-thalassemia, and hydroxyurea therapy.

RESULTS

The mean age of the 39 children was 8.2±2.2 years old. The average height was -0.75±0.30 SDS, and 10.3% (4/39) had short stature. Adjusted levels of IGF-1 or IGFBP-3 were significantly higher in children with sickle cell anemia on hydroxyurea treatment, in children with HbF levels >10%, and in those without alpha-thalassemia. Using SDS, the growth potential of children with sickle cell anemia in relation to their parents, calculated by the difference between AHP and TH, as well as the difference between children's height and their TH, were lower in children with co-inheritance of alpha-thalassemia Conclusion: The study showed an association between modifying factors and the GH/IGF-1 axis in children with sickle cell anemia. Additionally, the co-inheritance of alpha-thalassemia was associated with decreased height in these children when adjusted for their parents' height.

Epidemiology of Male Hypogonadism

The epidemiology of male hypogonadism has been understudied. Of the known causes of endogenous androgen deficiency, only Klinefelter syndrome is common with a likely population prevalence of greater than 5:10,000 men (possibly as high as 10-25:10,000). Mild traumatic injury might also be a common cause of androgen deficiency (prevalence 5-10:10,000 men), but large, long-term studies must be completed to confirm this prevalence estimation that might be too high. The classic causes of male androgen deficiency-hyperprolactinemia, pituitary macroadenoma, endogenous Cushing syndrome, and iron overload syndrome-are rare (prevalence < 10,000 men).

Compensated hypogonadism in men with sickle cell disease

OBJECTIVE

To evaluate the prevalence of hypogonadism in a population of men with SCD and characterize its aetiology. Sickle cell disease (SCD) is associated with the development of hypogonadism, but there is still controversy regarding its aetiology and clinical implications.

METHODS

We performed a cross-sectional study of 34 men with SCD aged > 18 years. Sociodemographic and clinical data, including anthropometric measurements (weight, height and BMI), were obtained. Early morning, blood samples were collected and total testosterone (TT), free testosterone (FT), luteinizing hormone (LH), follicle stimulating hormone (FSH), a complete blood count and haemoglobin electrophoresis were measured. Eugonadism was defined as T ≥300 ng/dL and LH ≤9.4 mUI/mL; primary hypogonadism as T < 300 ng/dL and LH > 9.4 mUI/mL; secondary hypogonadism as T < 300 ng/dL and LH ≤ 9.4 mUI/mL; and compensated hypogonadism as T ≥ 300 ng/dL and LH > 9.4 mUI/mL.

RESULTS

Median age was 33 (26-41) years, and SS genotype was the most frequent (73.5%). The prevalence of eugonadism, compensated hypogonadism and secondary hypogonadism was 67.5%, 26.4% and 5.88%, respectively. No men with primary hypogonadism were identified in our sample. Those with compensated hypogonadism had also higher FSH levels (>7.8 mUI/mL, P < .0001).

CONCLUSION

In our study population of men with SCD, a high prevalence of compensated hypogonadism was identified, which is a controversial and distinct clinical entity that warrants monitoring and further research.