Circulating adipocyte fatty acid binding protein levels in healthy preterm infants: Positive correlation with weight gain and total-cholesterol levels.

BACKGROUND: Adipocyte fatty acid binding protein (a-FABP) has been suggested to play an important role in the pathogenesis of metabolic syndrome. Preterm infants are at risk for the later development of insulin resistance, and, possibly, other components of metabolic syndrome. AIM: To determine circulating levels of a-FABP in preterm infants and examine possible associations of a-FABP with metabolic indices (serum lipids, glucose, and insulin levels, and homeostasis model assessment index of insulin resistance [HOMA-IR]), levels of leptin and adiponectin, anthropometric parameters and weight gain. STUDY DESIGN: Prospective cohort study. SUBJECTS: 55 healthy preterm (mean [SD] gestational age 32.8 [1.8] weeks) and 23 fullterm infants (reference group). OUTCOME MEASURES: Serum a-FABP, lipids, glucose, insulin, leptin and adiponectin levels at 31.9 [10.4] days of life. RESULTS: Serum a-FABP levels did not differ significantly between preterm and fullterm infants. A-FABP levels correlated positively with total-cholesterol [total-C] in both preterm and fullterm infants (beta=0.33; p=0.01 and beta=0.33; p=0.04, respectively). In addition to total-C, weight gain correlated independently with a-FABP levels in preterm infants (beta=0.36, p=0.01). CONCLUSIONS: An association between a-FABP levels and indices of insulin resistance was not present in infants studied. As the development of insulin resistance in children born prematurely is possibly associated with weight gain in early postnatal life, follow-up of our study population is necessary to demonstrate whether a-FABP levels, shown to correlate with weight gain in preterm infants, are a predictive marker for the later development of insulin resistance in these infants.

Disparity in circulating adiponectin multimers between term and preterm infants.

AIMS: To study circulating levels and distribution of adiponectin multimers [low molecular weight (LMW)-, medium molecular weight (MMW)- and high molecular weight (HMW)-adiponectin] in preterm and full-term infants. METHODS: Total serum adiponectin and its multimers were measured in 40 healthy infants at the age of one month and associations with anthropometric parameters [body weight and length, body mass index (BMI)], weight gain and metabolic indices (glucose, insulin) were examined. Twenty of the infants were born preterm (gestational age 33.2+/-1.6 weeks). RESULTS: LMW-adiponectin level and its fractional ratio to total adiponectin were significantly higher in full-term than in preterm infants (P<0.001 and P<0.01, respectively), whereas, MMW-adiponectin level and its ratio were significantly lower (P=0.03 and P=0.01, respectively). HMW-adiponectin did not differ significantly between full-term and preterm infants and accounted for almost 60% of total adiponectin levels in both groups. HMW-adiponectin, but not MMW adiponectin or LMW adiponectin, correlated significantly with anthropometric measurements, similarly to total adiponectin; in addition, HMW adiponectin correlated significantly with weight gain. CONCLUSIONS: HMW adiponectin is the most prevalent form in infants. Circulating levels and distribution of MMW- and LMW-adiponectin differ between full-term and preterm infants, but the role of these adiponectin multimers needs to be studied further.