Table 2. Human Milk Amino Acid Concentrations.
Human milk amino acid concentrations (nmol/mL) from 0.5, 2, and 6 months postpartum are presented as mean ± SEM. Independent samples t-tests were performed where p < 0.05 was considered significant. NW = normal weight, OB = obese, Arg = arginine, Ala = alanine, Asn = asparagine, Asp = aspartic acid, C-C = cystine, Glu = glutamic acid, Gln = glutamine, Gly = glycine, His = histidine, Ile = isoleucine, Leu = leucine, Lys = lysine, Phe = phenylalanine, Pro = proline, Ser = serine, Tyr = tyrosine, and Val = valine.
| 0.5 Months | 2 Months | 6 Months | |||||||
|---|---|---|---|---|---|---|---|---|---|
| NW (N = 74) |
OB (N = 77) |
P - Value |
NW (N = 66) |
OB (N = 63) |
P - Value |
NW (N = 53) |
OB (N = 40) |
P - Value |
|
| Branched-chain Amino Acids (nmol/mL) | |||||||||
| Ile | 10.3 ± 1.0 | 16.7 ± 1.2 | <0.001 | 10.4 ± 0.6 | 16.3 ± 1.0 | <0.001 | 10.3 ± 0.5 | 14.6 ± 1.0 | <0.001 |
| Leu | 25.5 ± 2.6 | 36.7 ± 2.7 | 0.003 | 27.5 ± 1.2 | 37.0 ± 2.3 | <0.001 | 29.2 ± 1.1 | 33.5 ± 1.9 | 0.044 |
| Val | 40.7 ± 2.2 | 48.5 ± 2.6 | 0.023 | 47.7 ± 2.2 | 49.6 ± 1.9 | 0.517 | 42.8 ± 2.0 | 44.9 ± 2.5 | 0.502 |
| Aromatic Amino Acids (nmol/mL) | |||||||||
| Phe | 10.1 ± 0.6 | 13.2 ± 0.8 | 0.004 | 11.9 ± 0.7 | 14.3 ± 0.8 | 0.020 | 12.3 ± 0.7 | 16.2 ± 1.1 | 0.004 |
| Tyr | 13.6 ± 0.9 | 20.3 ± 1.4 | <0.001 | 12.9 ± 0.9 | 18.9 ± 1.2 | <0.001 | 13.2 ± 0.9 | 17.3 ± 1.2 | 0.006 |
| Other Amino Acids (nmol/mL) | |||||||||
| Ala | 158.8 ± 8.3 | 165.4 ± 8.3 | 0.556 | 188.6 ± 8.7 | 209.7 ± 10.6 | 0.122 | 211.1 ± 8.2 | 210.9 ± 11.6 | 0.988 |
| Asn | 13.2 ± 1.4 | 11.5 ± 1.4 | 0.397 | 19.0 ± 21.7 | 11.6 ± 1.4 | 0.001 | 23.0 ± 2.2 | 14.2 ± 2.2 | 0.006 |
| Asp | 44.7 ± 3.1 | 52.9 ± 3.3 | 0.070 | 58.2 ± 4.2 | 87.4 ± 5.9 | <0.001 | 81.2 ± 7.0 | 104.3 ± 8.8 | 0.041 |
| C-C | 12.9 ± 0.7 | 10.2 ± 0.8 | 0.013 | 21.6 ± 1.0 | 14.5 ± 0.8 | <0.001 | 20.9 ± 1.1 | 19.7 ± 1.5 | 0.512 |
| Gln | 108.6 ± 11.4 | 102.7 ± 10.9 | 0.711 | 406.7 ± 21.5 | 286.2 ± 18.7 | <0.001 | 535.1 ± 21.8 | 337.9 ± 26.3 | <0.001 |
| Glu | 645.8 ± 25.4 | 606.3 ± 24.5 | 0.265 | 851.5 ± 26.6 | 743.0 ± 23.5 | 0.003 | 866.2 ± 24.8 | 789.9 ± 25.5 | 0.038 |
| Gly | 70.6 ± 3.5 | 66.1 ± 3.2 | 0.348 | 105.9 ± 4.9 | 86.5 ± 4.0 | 0.003 | 126.5 ± 5.0 | 98.5 ± 5.6 | <0.001 |
| His | 32.2 ± 1.7 | 22.1 ± 1.9 | <0.001 | 33.5 ± 1.7 | 22.7 ± 1.6 | <0.001 | 28.9 ± 1.4 | 17.7 ± 1.7 | <0.001 |
| Lys | 33.8 ± 3.2 | 44.1 ± 4.3 | 0.059 | 21.6 ± 2.2 | 24.9 ± 2.7 | 0.348 | 19.8 ± 1.9 | 21.0 ± 2.2 | 0.691 |
| Pro | 44.4 ± 3.1 | 52.1 ± 3.2 | 0.084 | 40.7 ± 1.9 | 42.0 ± 2.3 | 0.672 | 36.0 ± 1.4 | 38.6 ± 1.9 | 0.265 |
| Ser | 94.9 ± 4.7 | 94.9 ± 4.0 | 0.997 | 147.3 ± 6.0 | 125.1 ± 4.7 | 0.004 | 171.8 ± 7.7 | 132.9 ± 7.0 | <0.001 |