Low circulating insulin-like growth factor I in coeliac disease and its relation to bone mineral density.

BACKGROUND

Patients with coeliac disease have low bone mineral density (BMD), but the underlying mechanisms are unclear. Our aim was to study circulating insulin-like growth factor I (IGF-I) and its possible relationship to BMD in adults with untreated coeliac disease and after 1 year on a gluten-free diet.

METHODS

In 29 consecutive adult coeliac patients fasting IGF-I and BMD (n = 28) were examined before and 1 year after starting a gluten-free diet. Intact parathyroid hormone (PTH) was measured (n = 20) before the gluten-free diet was started.

RESULTS

Untreated coeliac patients had lower IGF-I values than controls matched for age and sex, and their BMD was low. A relationship was observed between BMD and IGF-I but not independent of age and body mass index. During the 1st year on a gluten-free diet BMD increased (P < 0.001), as did the circulating IGF-I levels in 21 of the 29 patients (P = 0.078). In the subgroup of 14 patients with normal initial PTH the increase in IGF-I correlated positively with the increase in BMD (femoral trochanter, r = 0.62, P < 0.05, and lumbar spine, r = 0.70, P < 0.02).

CONCLUSIONS

BMD and circulating IGF-I levels are low in adults with untreated coeliac disease. In patients with normal initial PTH level there is an association between the change in BMD and circulating IGF-I, although this parallel increase may not be causally connected.