Table 4.
Total Nitrogen Intake, Excretion, and Balance for Elderly Women
| Trial | |||
|---|---|---|---|
| Measure | LPro | MPro | HPro |
| Dietary nitrogen intake (mg N·kg−1·d−1) | |||
| Week 2 | 84.2 ± 0.8 | 120.9 ± 1.0 | 169.9 ± 2.4 |
| Week 3 | 83.6 ± 0.6 | 121.4 ± 0.8 | 171.0 ± 2.8 |
| Nitrogen excretion (mg N·kg−1·d−1) | |||
| Urine | |||
| Week 2 | 71.8 ± 2.9 | 90.4 ± 2.0 | 119.6 ± 3.5 |
| Week 3 | 56.9 ± 2.4† | 79.0 ± 0.8 | 102.2 ± 3.0† |
| Stool‡ | 33.1 ± 2.5 | same | |
| Miscellaneous§ | 8.0 | same | |
| Nitrogen balance∥(mg N·kg−1·d−1) | |||
| Week 2 | −14.5 ± 3.1 | 3.8 ± 2.5 | 23.4 ± 3.3 |
| Week 3 | −0.1 ± 2.7 | 8.5 ± 3.6 | 42.0 ± 3.0 |
Notes: Values are reported as mean ± SEM. LPro denotes 0.53 ± 0.02 g of protein·kg−1·d−1; MPro at 0.76 ± 0.02 mg N·kg−1·d−1; and HPro at 1.06 ± 0.05 mg N·kg−1·d−1.
†
A comparison of urinary nitrogen excretion in Week 2 vs. Week 3 for LPro (p < .002) and HPro (p < .002). A comparison between trials at Week 2 and at Week 3 was highly significant.
‡
Stool calculations are the mean nitrogen output from all trials combined and collected during Week 2. Stool nitrogen output was not significantly different among trials.
§
Miscellaneous losses assumed to be 8 mg N·kg−1·d−1 (17).
∥
Nitrogen balance, equal to dietary nitrogen intake minus (urine + stool + miscellaneous N excretions).