Bone mass and metabolism in patients with celiac disease

Several aspects of the pathogenesis of osteopenia in celiac disease are still unclear. Therefore, bone mass and metabolism were evaluated in adults with celiac disease in a cross-sectional study.

Bone mineral density (BMD), assessed by total body dual-photon absorptiometry, and serum indices of bone metabolism and remodeling were evaluated in 17 patients with untreated celiac disease, 14 with celiac disease on a gluten-free diet, and 24 healthy volunteers.

BMD, expressed as a z score, was significantly lower in patients with untreated celiac disease than in patients with treated celiac disease and volunteers and lower in patients with treated celiac disease than in volunteers. Similar changes were observed in serum calcium level, whereas intact parathyroid hormone level was significantly higher in untreated than in treated patients with celiac disease and volunteers, and no difference was found between the latter two groups. 25-Vitamin D level was significantly lower and 1,25-vitamin D level significantly higher in untreated celiac disease than in treated celiac disease and volunteers. Indices of bone remodeling were significantly higher in untreated than in treated patients and volunteers and significantly and positively correlated with iPTH in untreated patients with celiac disease.

BMD is almost invariably low in patients with untreated celiac disease. Results in treated patients suggest that gluten-free diet improves but does not normalize BMD. Untreated celiac disease is characterized by high levels of 1,25-vitamin D and by increased bone turnover, caused by the increase in intact parathyroid hormone level.