LEPTIN IS PRESENT IN HUMAN-MILK AND IS RELATED TO MATERNAL PLASMA LEPTIN CONCENTRATION AND ADIPOSITY

Leptin is elevated during pregnancy and may be involved in the regulat ion of milk production in women. Immunoreactive leptin was quantified in human milk by modified radioimmunoassay. Leptin concentration was h igher in whole vs. skim milk fractions; however, leptin concentration was not correlated with percentage milk fat, Leptin concentrations in whole and skim milk were correlated with maternal plasma leptin concen trations, maternal body weight, body mass index, and tricep skinfold t hickness, but not with plasma insulin concentration. These data provid e the first evidence for the presence of leptin in human milk in the r ange of concentrations found in human plasma and indicate that the con centration of leptin in milk reflects maternal adiposity. Determining the biological role(s) of milk-borne leptin could add to our understan ding of neonatal metabolism and the mechanisms underlying the developm ent of body fat and obesity in humans. (C) 1997 Academic Press.