Adipokines and Macronutrients Content in Breast Milk: Relationship with Maternal Characteristics and Anthropometric Parameters of Full-Term and Preterm Newborns

Abstract

Introduction. Breast milk (BM) is a unique heterogeneous array of essential macronutrients and micronutrients, hormones, immunoglobulins and other bioactive molecules providing an optimal nutritional source for infants. Breastfeeding offers both short and long-term benefits to babies. Purpose. To analyze the features of adipokines and macronutrients content in breast milk and to assess their relationship with maternal characteristics and anthropometric parameters of full-term and preterm newborns Materials and methods. The prospective study involved 35 mother-child couples who received medical care at the Republican Scientific and Practical Center "Mother and Child" from May to July 2022. The age of mothers was 32.0 (27.0–35.0) years, pregravid BMI was 24.1 (20.2–29.3) kg/m2. Two groups of women were assigned according to the term of delivery: group 1 (Gr1) – at 266 (259-280) days of gestation (full-term pregnancy) (n=18), group 2 (Gr2) – at 190 (182–196) days of gestation (n=17). The body weight of Gr1 children was 3360 (2940–3530) g, Gr2 – 860 (800–890) g, p<0.001. Breast milk samples were collected on day 16.0 (10.0–29.0) of infant life. Protein, fat and carbohydrates content and energy values in whole homogenized breast milk were determined by infrared spectrometry. Leptin and adiponectin were analyzed by enzyme immunoassay. Results. BM leptin concentration was 0.109 (0.043–0.152) ng/ml in all subjects, BM adiponectin content was 5.31 (4.21–7.76) ng/ml. Leptin and adiponectin levels in newborns of both Gr1 and Gr2 did not differ (p=0.228 and p=0.368, respectively). Statistically significant differences in fat content and energy value of breast milk received by newborns of two study groups were revealed. Preterm infants received as nutrition BM with statistically significantly higher fat content (p=0.031) and energy value (p=0.036). Breast milk leptin levels in mothers with pre-pregnancy overweight/obesity were statistically significantly higher than those of mothers with normal BW (p=0.035). Protein content in milk during the first month correlated with lactose levels in BM in both term and preterm births. The relationship between adiponectin levels and lactose concentration in breast milk of preterm newborns mothers was established. Statistically significant correlations were established between BM adiponectin and the age of full-term newborns mothers, BM leptin and pre-gravid BW, BMI, and BW of women on the eve of term labor, BM leptin and z-score BW, and z-score body length in full-term newborns. Conclusions. The revealed features of adipokines and macronutrients content in breast milk, their relationship with maternal characteristics and anthropometric indicators of newborns may determine the long-term role of maternal milk as a metabolic programming factor. Additional studies are needed to assess clinical significance of postnatal changes in main milk components and the impact of such changes on infant growth and development.