Cord serum visfatin at term birth: maternal smoking unmasks the relation to foetal growth

Summary Objective  Visfatin is an adipocytokine involved in insulin action and oxidative stress. The regulation of circulating concentrations in the human foetus is unknown. We studied whether, at term birth, the serum concentrations of visfatin are related to foetal size, both in the absence and in the presence of maternal smoking during pregnancy. Design  A cross-sectional, hospital-based study. Patients  Seventy-eight singleton, healthy neonates [39 girls and 39 boys; gestational age (GA) 39·5 ± 0·2 weeks; birth weight (BW) 3·3 ± 0·04 kg]. Methods  Cord serum visfatin, insulin and IGF-I measured by specific immunoassays. Results  In infants from nonsmoking mothers (N = 48), cord serum visfatin levels were unrelated to either BW or birth length (BL). In infants from smoking mothers (N = 30), however, serum visfatin was inversely associated with both BW (r = −0·57; P < 0·001) and BL (r = −0·60; P < 0·0001) and it was directly associated with the number of cigarettes smoked (P < 0·05) in heavy smokers. In a multiple regression analysis, cord serum visfatin accounted for 36% of BW and 32% of BL variance in infants from smoking mothers. Cord serum visfatin was unrelated to insulin or IGF-I in either subgroup. Conclusion  At term birth, there is no readily detectable relation between circulating visfatin and indices of foetal size; however, maternal smoking unmasked a strikingly inverse relationship between cord serum visfatin and the foetal growth status, indicating that smoking can elicit a rise or a fall of cord serum visfatin, depending on whether the foetus is, respectively, of smaller or larger size.