Association between iron overload and osteoporosis in patients with hereditary hemochromatosis.

SUMMARY: In 87 patients with hereditary hemochromatosis, osteoporosis was detected in 25%, and osteopenia in 41%. Bone mineral density was independently associated with BMI, ALP levels, hypogonadism/menopause, and the amount of iron removed to reach depletion, but not with cirrhosis. Osteoporosis is influenced by iron overload in hemochromatosis.

INTRODUCTION: To analyze prevalence, clinical characteristics and genetic background associated with osteoporosis in a retrospective study in Italian patients with hereditary hemochromatosis (HHC).

METHODS: In 87 consecutive patients with HHC, bone mineral density was systematically evaluated by dual energy x-ray absorptiometry of the lumbar spine (n = 87) and femoral neck (n = 66).

RESULTS: Osteoporosis was detected in 22 (25.3%), and osteopenia in 36 (41.4%) patients. Mean Z scores were -0.92 +/- 1.42 at lumbar spine and -0.35 +/- 1.41 at femoral neck. Lumbar spine T-score was independently associated with total ALP (p = 0.002), hypogonadism/menopause (p = 0.026), and iron overload (p = 0.033 for ferritin and p = 0.017 for iron removed). We observed a borderline significance for BMI (p = 0.069) and smoking status (p = 0.086). Lumbar spine osteoporosis was independently associated with lower BMI (OR 0.73, 95% CI 0.54-0.94), total ALP (OR 1.17, 95% CI 1-1.39 per 10 unit increase) and the amount of iron removed (OR 1.53, 95% CI 1-2.5 per 5 g increase). HFE genotypes did not differ between patients with and without osteoporosis.

CONCLUSIONS: Osteoporosis is observed in a quarter of unselected patients with HHC, independently of the genetic background, and is associated with ALP, hypogonadism, body weight, and severity of iron overload.