Location: Arkansas Children's Nutrition CenterTitle: Development of resting cardiovascular activity during the first 2 years of life differs in breastfed and formula-fed boys and girls Author
Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract Only
Publication Acceptance Date: 11/15/2011
Publication Date: 4/1/2012
Citation: Pivik, R.T., Andres, A., Badger, T.M. 2012. Development of resting cardiovascular activity during the first 2 years of life differs in breastfed and formula-fed boys and girls. The FASEB Journal. 26(Meeting Abstracts):44.8. Interpretive Summary: Does early infant diet affect the development and control of heart rate? We studied these questions by analyzing resting heart rate recordings at 3, 6, 9, 12, and 24 mo in healthy children who were breastfed or fed milk formula or soy formula during infancy. All groups showed the expected slowing of heart rate with age. However, after 6 months levels of autonomic nervous system activity regulating heart rate were higher in formula-fed than breastfed infants, and these differences became evident earlier in girls than boys. The regulation of heart rate influences attention, emotion, cognition, and behavior. The present findings suggest that early infant diet may help determine individual differences in these functions. Of relevance to concerns about potential adverse influences of soy formula on early development, we found no indication of effects specific to soy formula.
Technical Abstract: To investigate whether early infant diet influences cardiovascular development we recorded resting heart-rate (HR) at 3, 6, 9, 12, and 24 mo in awake healthy children who were breastfed (BF) or fed milk formula (MF) or soy formula (SF) during infancy (n = 83-146/group/age). HR, and indices of autonomic nervous system (ANS) sympathetic [low frequency power (Plf: .04-.15 Hz)] and parasympathetic activity [high frequency power (Phf: .15-.5 Hz)] were determined from power spectral analyses of digitized, artifact-free recordings and analyzed using ANOVAs with post-hoc t-tests. HR decreased and Plf and Phf increased for all groups across the study period. Few within-group gender differences were found [6 mo Plf: MF girls > boys, p < .05; 12 and 24 mo HR: SF girls > boys, both p < .05]. There were three important diet-related findings: 1) levels of Plf and Phf were higher in BF than formula-fed (FF) groups after 6 mo (p < .001); 2) SF and MF infants did not differ on HR measures; 3) and, group differences were modulated by gender [greater Plf and Phf in FF than BF girls from 9-24 mo (p < .02) and in FF than BF boys at 12 and 24 mo (p < .01)]. Baseline levels of ANS activity influence interactions between the central nervous system and ANS that regulate attention, emotion, cognition and behavior. The present findings suggest early infant diet may contribute to individual differences in these functions.