Basal endocrine status in African dietary iron overload.

Abstract

Endocrine disturbances, notably diabetes, have been well described as a complication of iron overload due to hereditary hemochromatosis and beta-thalassemia. Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis has also been well documented. The pattern of iron loading in African iron overload with saturated transferrin is similar to that seen in hereditary hemochromatosis. In addition, many symptoms ascribed to pituitary dysfunction are common to both conditions. The present study was undertaken to assess whether a similar pattern of endocrine dysfunction occurs in African iron overload. Thirty subjects with African iron overload and transferrin saturation >50%, plus 30 age and sex matched normal controls were studied. An iron profile, fasting plasma glucose, cortisol, DHEA-S, LH, FSH, growth hormone, prolactin, TSH, and FT4 levels were measured in all 60 subjects as well as testosterone in the males and estradiol in the females. Iron loading in the subjects with increased transferrin saturation ranged from moderate to severe. No significant differences were found in the mean testosterone, estradiol, LH, DHEA-S, growth hormone, prolactin, or TSH levels between the subjects and normal controls. In female subjects, although within the normal range, the mean FSH level was significantly higher, probably due to their being somewhat older and in a more advanced stage of menopause than the control females. Mean cortisol concentrations were increased in both genders in the patient group, significantly so in the females; however, values were within the reference range. We conclude therefore that there appears to be no major impairment of endocrine function in the basal state in African iron overload subjects with moderate to severe degrees of iron loading.