Association of circulating FGF-21 levels in the first week of life and postnatal growth in hospitalized preterm infants

BACKGROUND: The role of fetal and neonatal growth in the development of adult-onset diseases such as obesity and metabolic syndrome has become increasingly appreciated. Fibroblast growth factor-21 (FGF-21) is known as a regulator of glucose and lipid metabolism. FGF-21 levels are elevated in obese adults and children. The role of FGF-21 in neonatal growth in preterm infants is not known. OBJECTIVES: We aimed to evaluate the association of circulating FGF-21 levels in the first week of life and neonatal growth parameters at the time of discharge from NICU. METHODS: We performed a longitudinal study of 25 preterm neonates admitted to NICU. Blood samples were collected at two time points: within 24 h of life (T1), and 24–96 h after the first blood draw (T2). FGF-21 levels were measured in plasma by ELISA. Weight, length, BMI and their Z-scores were measured at the time of birth and discharge. RESULTS: The FGF-21 levels were significantly higher at T2 than at T1 (p < 0.001). FGF-21 levels at both time points were positively correlated with gestational age (r = 0.43, p = 0.03). FGF-21 at T1 was positively associated with weight Z-score (β = 0.19, p = 0.001) and length Z-score at discharge (β = 0.21, p = 0.03). CONCLUSIONS: Circulating FGF-21 levels increase significantly in the first week, and the FGF-21 levels within the first 24 h are positively associated with weight and length Z-scores at discharge in preterm infants. These results suggest that FGF-21 may be involved in growth and developmental maturation.