Abstract 154

Background/aim: Dexamethasone (Dx) treatment has been widely used for early treatment of chronic lung disease of prematurity (CLD). Yet, in recent animal experiments Dx has shown to have unfavorable effects on bone development. We hypothesize that the effects of Dx treatment of VLBW infants may still be reflected in osteoblastic activity even after early postnatal growth period.

Subjects: We examined 23 premature infants, born at Kuopio University Hospital, Kuopio, with mean (range) gestational age (GA) 28 (24-32) wks, mean (range) GA-specific birth weight -0.64(+1.88 to -3.38) SD-units. All infants got fortified human milk with uniform vitamin and mineral supplementation until discharge.

Measurements: S-OC, indicator of osteoblastic activity, were measured in all infants when the weight of 2.5 kg was attained. Discriminant analysis (SPSS/PC version 6.0) was performed to see which perinatal factors (GA, intrauterine growth status, the weight gain from birth to 2.5 kg and Dx treatment) were associated with high S-OC.

Results: Differences were found neither in median S-OC values between infants with GA ≤28 wks [5.4 ug/l] vs. infants with ga >28 wks [4.6 ug/l] (p=0.525) nor between AGA [5.5 ug/l] vs. SGA [5.3 ug/l] infants. In the discriminant analysis, early Dx treatment (but no other perinatal factors studied) was associated with high S-OC levels (p = 0.041).

Conclusions: Bone mineral density measurements are indicated in Dx-treated VLBW infants if bone development under these circumstances are to be evaluated.