Osteocalcin and Human Milk

William B. Pittard, III, Kitty M. Geddis, Bruce W. Hollis
1993 Neonatology  
Introduction The serum concentration of osteocalcin [α-carboxyglutamic acid (GLA) protein] has been reported to be significantly greater in breastfed than in formula-fed infants [1,2]. Further, osteocalcin is a potent chemoattractant for peripheral blood monocytes, a major cell type found in human milk [3]. Therefore, to test the hypothesis that osteocalcin is present in human milk, the osteocalcin concentration was measured in blood and milk from 11 2-3 day postpartum lactating women.
more » ... and Methodology This investigation was approved by the Medical University of South Carolina Human Investigation Committee and written consent was obtained from each patient prior to initiating the study. Eleven 2-3 day postpartum lactating women were chosen randomly. Demographic data including age, obstetrical index, mode of delivery and medical complications were recorded for each mother, and birth weight, gestational age, and Apgar scores were recorded for the infants. Gestational age of infants at birth was initially determined from the history of the mother's last menstrual period and was confirmed with a Ballard examination within 36 h of delivery. Milk collection (20 ml) was performed by the women either manually or using an electric breast pump (Medela, Crystal Lake, Illinois), based on individual preference. Blood (10 ml) was obtained using routine methods of peripheral venipuncture. Both milk and blood specimens were collected between 11:00 a.m. and noon to minimize any effect of the previously reported diurnal variation in osteocalcin serum concentration [4]. Blood was divided into two aliquots. One aliquot was taken immediately after collection to the laboratory where it was centrifuged (200 g for 10 min) and the serum was separated and stored at -20 º C until all specimens were ready for osteocalcin analysis. The second aliquot was placed in a tube containing ethylene-diamine-tetraacetic acid and taken to the hospital clinical laboratory for a total white blood cell count (via Coulter counter) and a routine differential cell count with Wright's staining. Milk specimens were taken immediately to the laboratory after collection. The specimens were divided approximately in half using a sterile technique. The first half was used for total and differential cell counts of the milk. To determine the total cell count, centrifu-gation and a standard hemocytometer were used. The differential cell count was performed on a cytocentrifuged preparation following Wright's staining.
doi:10.1159/000243909 pmid:8443295 fatcat:jyhmzxqvc5f6vluoe44dnc7njy