BONE MINERAL DENSITY AND BIOCHEMICAL VARIABLES OF THE IGF SYSTEM IN SMALL FOR GESTATIONAL AGE CHILDREN

SILVANO LILIANA1, PÉREZ ADRIANA2, MIRAS MIRTA1, MUÑOZ LILIANA1, PRETEL ESTEBAN2, PICOTTO GABRIELA2, MARTIN SILVIA1, ELÍAS VANINA2, SOBRERO GABRIELA1, DE GRANDIS SUSANA3, ARMELINI PEDRO3, TOLOSA DE TALAMONI NORI2

Buenos Aires

Congreso; XXII Reunión Anual de la Asociación Argentina de Osteología y Metabolismo Mineral; 2005

Body mass is associated with bone mineral density (BMD), which is determined by genetic and environmental factors. The present work was designed to relate BMD and calcium and phosphorus metabolism biochemical variables in small for gestational age (SGA) children, with vitamin D (VDR) and estrogen receptor (ER) genotypes. Children (n=72) included controls, SGA with postnatal catch-up and without catch-up. Serum calcium and phosphorous, PTH, osteocalcin and beta cross-laps (EQLIA), IGF-I and IGFBP3 (IRMA) and acid labil subunit (ALS) by EIA, were measured. DNA was isolated from blood. VDR genotypes were determined using Bsm-I and Fok-I restriction enzymes, while for ER genotypes, Pvu-II y Xba-I were employed. BMD were analyzed in lumbar spine and femoral neck using DEXA (Norland). SGA children without catch-up have lower femoral neck and lumbar spine BMD than those from SGA children with catch-up or control ones (p< 0.01); they also showed lower levels of serum IGF-I, IGFBP3 and ALS (p< 0.01). VDR and ER polymorphism distribution did not show statistically significant differences between groups. Nevertheless, a better femoral BMD in the control group is correlated with the Ff genotype. In conclusion, SGA children without catch-up have biochemical variables related to the IGF system completely different of those from other groups and lower BMD values at both skeletal sites. A BMD-Fok I association is observed in control children while the same tendency has been shown in SGA children.