Demineralization in cystic fibrosis detected by direct photon absorptiometry.

Bone mineral content, bone width, and their ratio were measured in patients 
with cystic fibrosis (CF) using monoenergetic photon absorptiometry. Serial measurements of 
the radius and ulna were made in 27 patients with CF 
and were compared with 968 age-matched controls. Demineralization was found in 
37% of the boys and 63% of the girls. Patients under 
age 10 years had normal bone mineral content and nine of 
15 patients aged 13 or older were demineralized (P less than 
.01). Demineralization correlated with the extent of weight reduction in patients 
(P less than .001). Patients most likely to be demineralized were 
adolescent girls. To our knowledge, this is the first report of 
bone mineral status of children with CF, and the results indicate 
that a sizable proportion of these patients may be demineralized without 
overt rickets. 