Влияние полиморфизма rs9939609 гена FTO на прибавку массы тела при беременности, уровни лептина и ИПФР-1 в грудном молоке и рост младенцев на грудном вскармливании

Abstract

The search for possible ways of early prevention of obesity is an urgent task. Previous studies have provided evidence of the association of breast milk (BM) hormones with growth in young children. However, information on the influence of the mother’s genetic predisposition to obesity and her weight gain during pregnancy on their level is limited. Objective. To assess the effect of the rs9939609 polymorphism in the maternal FTO gene on body weight gain during pregnancy, the levels of leptin and insulin-like growth factor-1 (IGF-1) in BM, as well as the dynamics of the physical development of exclusively breastfed children. Patients and methods. The study involved 103 healthy women aged (M ± m) 32.2 ± 0.5 years, with a BMI of 19.8 ± 2.8 kg/m2 and their children living in Smolensk. Mothers gave informed consent to participate in the study. BM was taken on days 10–14, at 1 and 3 months of lactation. Levels of leptin and IGF-1 were determined in the morning midstream portion of BM serum by ELISA. Anthropometric data of children were assessed at birth, at 1 and 3 months of life using the WHO Anthro software (2009) by calculating the Z-scores of “weight-for-age” (WAZ) and “length-for-age” (LAZ). The women were genotyped for rs9939609 by real-time PCR. Results. Mothers with the TT genotype (frequency of occurrence – 62%) had higher body weight gain during pregnancy than carriers of the AT (22%) and AA (16%) genotypes, as well as significantly higher leptin and lower IGF-1 levels in BM during the entire observation period. Their infants had significantly lower WAZ at birth and at 1 month and LAZ at 3 months of life than children born to mothers with the AA and AT genotypes. Conclusion. Lower parameters of the physical development of infants born to mothers with the TT genotype of the rs9939609 polymorphism in the FTO gene can be explained by their low genetic predisposition to obesity. However, we cannot exclude the existence of an additional mechanism of growth restriction due to the influence of BM hormones on it, i.e., a reduced level of IGF-1 and the anorexigenic effect of an increased level of leptin, probably associated with a higher BMI and weight gain in mothers with the TT genotype over the period of pregnancy. Key words: anthropometry, breast milk, insulin-like growth factor-1, leptin, rs9939609 polymorphism, pregnancy weight gain