Objective: To determine whether the osteoarticular changes associated with genetic hemochromatosis could be explained by metabolic parathyroid hormone (PTH) disorders.
Methods: The study involved 210 patients with liver iron overload syndromes. Osteoarticular changes were numerically scored as the number of damaged joints. PTH 1-84 and 44-68 were assayed.
Results: An increase in serum PTH 44-68 levels was found in one-third of untreated patients who had no calcium or PTH 1-84 abnormalities. Serum PTH 44-68 levels correlated positively with serum ferritin levels. In multivariate analyses, the number of affected joints correlated positively with age, serum PTH 44-68 levels, and serum ferritin levels.
Conclusion: Liver iron overload syndromes, especially genetic hemochromatosis, are associated with elevated circulating levels of PTH fragments containing the 44-68 region, which appears to play a role in osteoarticular changes. This increase seems to be a consequence of iron overload.