부산대학교 도서관

We reported that bone mineral content (BMC) in the first 6 mos of life was decreased in breast-fed infants without vitamin D, vs breast with D or formula-fed infants. No data have been reported on BMC and bone width (BW) in healthy children from 1 to 7 yrs. We hypothesized that BMC increases with age and is lower in females, with no difference by previous breast vs formula intake, or sun exposure. BMC and BW were determined on 96 children 1-7 yrs using direct photon absorptiometry at 1/3 distal radius. BMC (gm/cm) was highly correlated with age (r=.81, p<.001). Mean (±sd) BMC values for l-, 2-, 3-, 4-, 5-, and 6-year olds were .140 (±.020), .174 (±.031), .215 (±.046), .254 (±.047), .272 (±.041) and .363 (±.058) gms/cm. BW also increased with age (r=.23, p=.03) with means of 7.8 (±.9), 8.5 (±1.4), 9.2 (±1.3), 9.0 (±1.4), 8.8 (±1.1), and 9.6 (±.9) mm resp. Females had lower BMC vs males: .219 (±.063) vs .259 (±.080) resp (p<.01): there was no sex difference at 12-47 mo; 48-83 mo females had lower BMC than males (.262 ±.053 vs .301 ±.066 resp, p=.03). BMC was not related to previous breast or formula feeding, even after adjusting for time since discontinuation (p=.9). BMC correlated with hrs of sun exposure per week (r=.31): but not (p=0.9) when age was controlled (multiple regression). Thus, bone mineral content increases significantly and linearly with age from 1 to 7 yrs; females have lower BMC than males after 4 years. Age and probably sex specific comparisons should be made in childhood BMC studies.