A 52-year-old male presented with impotence. He had a four-year history of insulin-dependent diabetes mellitus. There was no history of headaches or vomiting. The patient was a non-smoker and did not consume alcohol. Apart from insulin he took simple analgesia for joint pains.
Investigations are shown.
FBC Normal Sodium 135 mmol/l Potassium 4 mmol/l Urea 6 mmol/l Creatinine 100 mmol/l Bilirubin 12 mmol/l AST 200 iu/l ALT 220 iu/l Alkaline phosphatase 128 iu/l Albumin 8 g/l Thyroxine 100 nmol/l TSH 2.6 mu/l Testosterone 7 nmol/l (NR 10–35 nmol/l)
LH 1.5 iu/l (NR 1–10 iu/l) FSH 1 iu/l NR 1–7 iu/l) LHRH test: 20 min: 60 min: LH 3 iu/l 2 iu/l FSH 2 iu/l 2 iu/l
What test would you perform to confirm the diagnosis?
a. MRI scan of the brain.
b. Serum prolactin level.
c. Serum ferritin.
d. Dynamic pituitary function tests.
e. Liver ultrasound.
The clinical features and the data are consistent with the diagnosis of idiopathic haemochromatosis. The insulindependent diabetes mellitus suggests pancreatic
involvement, and abnormal liver function is consistent with hepatic infiltration. The patient has a low testosterone level with an inappropriately low gonadotrophin response indicating secondary hypogonadism due to excessive iron deposition in the pituitary. Secondary hypogonadism is the most
common endocrine deficiency in hereditary haemo chromatosis. Primary hypogonadism due to testicular iron deposition may occur with this disorder but is much less common than secondary hypogonadism. In the context of the question, a serum ferritin level >500 mg/l would be diagnostic of primary haemo chromatosis. Alcohol-related liver disease, chronic viral hepatitis, non-alcoholic steatohepatitis and porphyria cutanea tarda also cause liver disease and increased serum
ferritin con centrations even in the absence of iron overload. Hepatic iron overload in haemochromatosis is associated with an increased risk of hepatocellular carcinoma. Patients with haemochromatosis are also at increased risk of hypothyroidism and are susceptible to certain infections from siderophoric (iron-loving) organisms such as Listeria spp., Yersinia enterocolitica and Vibrio vulnificus, which are picked up from eating uncooked seafood.