THE INFLUENCE OF FEEDING REGIMENS ON ENDOGENOUS DIGOXIN-LIKE IMMUNOREACTIVE SUBSTANCE CONCENTRATIONS IN INFANTS

The aim of this study was to investigate serum digoxin-like immunoreac tive substance (DLIS) levels in 60 healthy term infants when they reac hed 1-6 months of age with regard to feeding regimen. Group I consiste d of 30 infants fed exclusively on breast milk. Groups II and III each consisted of 15 infants fed on formula and cow's milk, and on formula and cow's milk supplemented by breast milk, respectively. Mean serum DLIS concentrations were 0.03 +/- 0.05, 0.18 +/- 0.09 and 0.15 +/- 0.0 9 ng/ml in groups I-III, respectively. The difference between the DLIS levels in groups II and III was not significant. Serum DLIS levels of infants in groups II and III, on the other hand, were significantly h igher than in group I (p < 0.05). These findings were interpreted to s uggest that artificial nutrients may cause volume expansion and an inc rease in endogenous DLIS levels. The latter response is possibly a pro tective mechanism to decrease volume expansion in groups II and III.