Insulin-like growth factor-I, 25-hydroxyvitamin D, and bone mineral accrual during growth in females
Breen, Maria Elizabeth
MetadataShow full item record
This project sought to determine relationships among changes in plasma 25(OH)D, plasma IGFI, and BMC in prepubertal females (N = 76; aged 4 to 8 years), over a period of up to 9 years. BMC was measured using DXA. Plasma 25(OH)D and plasma IGF-I were assessed using ELISA and RIA, respectively. Linear mixed modeling that was employed to analyze the proportion of variance each explained on the four bone outcomes. IGF-I was more strongly associated with BMC accrual than 25(OH)D at the total proximal femur (R2 = 0.847 vs. 0.771), radius (R2 = 0.812 vs. 0.759), and lumbar spine (R2 = 0.759 vs. 0.698). At each skeletal site, the rate of BMC accrual was negatively associated with changes in 25(OH)D, but positively associated with changes in IGF-I. These longitudinal data in early adolescent females indicate that both 25(OH)D and IGF-I have a significant impact on bone mineral accrual.