Insulin, adiponectin, IGFBP-1 levels and body composition in small for gestational age born non-obese children during prepubertal ages.

BACKGROUND: Being small for gestational age (SGA) at birth and postnatal growth pattern may have an impact on insulin resistance and body composition in later life. Adiponectin is a strong determinant of insulin sensitivity.

OBJECTIVE: The aim of this study was to evaluate insulin resistance and adiponectin levels in SGA born children with catch-up growth (CUG) in the absence of obesity in prepubertal ages and relations with body composition and insulin-like growth factor binding protein (IGFBP)-1.

METHODS: Twenty-four (15F, 9M) SGA born children with CUG but without obesity were evaluated at age 6.3 +/- 0.5 years with respect to glucose, insulin, IGFBP-1, leptin and adiponectin levels, and body composition by dual-energy X-ray absorptiometry (DEXA). Their data were compared to that of 62 (27F, 35M) appropriate for gestational age (AGA) children.

RESULTS: SGA and AGA children had similar height standard deviation score (SDS) corrected for parental height and body mass index (BMI) SDS. Homeostasis model for insulin resistance (HOMA-IR) was significantly high in SGA (0.7 +/- 0.6) than in AGA children (0.4 +/- 0.2) (P = 0.029). There were no significant differences in leptin, IGFBP-1, adiponectin, and total and truncal fat between SGA and AGA children. However, being born SGA and having higher BMI in the upper half for the distribution in the sample, although within normal ranges, was associated with lower adiponectin levels (estimated means of log adiponectin levels 3.8 +/- 0.3 vs. 4.4 +/- 0.1 microg/ml, P = 0.040).

CONCLUSIONS: SGA children with CUG and with no obesity have higher insulin levels compared to AGA children. Both SGA birth and recent size seem to have an effect on serum adiponectin levels in childhood.