Small-for-gestational-age and predictors of HOMA indices, leptin and adiponectin in infancy

Aim: To assess whether small-for-gestational-age (SGA) - an indicator of poor fetal growth, may affect metabolic health biomarkers in infancy and explore the predictors.

Methods: This was a nested matched (1:2) prospective observational study of 65 SGA (birth weight < 10th percentile) and 130 optimal-for-gestational-age (OGA, birth weight 25th-75th percentiles, control) infants in the 3D birth cohort with subjects recruited in Canada from 1 May 2010 to 31 August 2012. The outcomes included homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-β), circulating leptin and adiponectin concentrations at age 2 years.

Results: HOMA-IR, HOMA-β, leptin and adiponectin concentrations were similar in SGA versus OGA infants. Female sex and accelerated growth in length during mid-infancy (3-12 months) were associated with higher HOMA-IR. Caucasian ethnicity and decelerated growth in weight during late infancy (12-24 months) were associated with lower HOMA-IR. Current BMI was positively associated with circulating adiponectin in SGA infants only (+13.4% [4.0%-23.7%] per BMI z score increment).

Conclusion: Insulin resistance and secretion, circulating leptin and adiponectin levels were normal in SGA subjects in infancy at age 2 years. The novel observation in SGA-specific positive association between current BMI and circulating adiponectin suggests dysfunctional adiposity-adiponectin negative feedback loop development during infancy in SGA subjects.