Assay of ghrelin concentration in infant formulas and breast milk

Table 1 Spike and recovery of ghrelin in human plasma (mean of the observed levels from 3 duplicate determinations in 3 separate assays)

Sample No.	Ghrelin added1 (pg/mL)	Recovery (%)
1	500	96
2	1000	90
3	2000	91

¹Different concentrations of human ghrelin were added to 3 different human plasma samples and the ghrelin content was determined by RIA. Percent recovery was calculated on the observed vs expected.

Table 2 Ghrelin concentrations in infant formulas, in mother's milk, in cow’s milk and in serum of lactating mothers, breast-fed infants and formula-fed infants

	Ghrelin concentration (pg/mL ± SD)
Milk
Different kinds of artificial infant formula (n = 19)	2007.1 ± 1725.36a
Breast milk (n = 20)	828.17 ± 323.32a
Non pasteurized cow milk (n = 5)	2816.00 ± 219.00
Serum
Lactating mothers (n = 20)	1319.18 ± 140.18
Breast-fed infants (n = 37)	1045.7 ± 263.38b
Formula-fed infants (n = 19)	1247.93 ± 328.07b

^aP = 0.005, infant formulas vs human milk, student’s t test;

^bP = 0.023, breast-fed infants vs formula-fed infants, student’s t test.

Table 3 Ghrelin concentrations in three different types of artificial infant formula

Type of infant formula	Ghrelin concentration(pg/mL ± SD)
Starting infant formulas (n = 9)	2699 ± 233.5
Follow-on infant formulas (n = 6)	2561 ± 215.2
Special infant formulas (anti-regurgitation and hydrolyzed casein protein formulas) (n = 4)	1160 ± 340