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Table 5 Equations to estimate protein equivalent of nitrogen appearance (PNA)

From: A practical approach to dietary interventions for nondialysis-dependent CKD patients: the experience of a reference nephrology center in Brazil

Equation 1 [48]:
PNA (g protein/day) = 9.35 × G + 11.04
Where:
G = Urea nitrogen generation x [urinary urea (g/L)/2.14 x urinary volume (mL) 24 h]/urine collection duration (min) (usually 1440)
or
Equation 2 [49]:
PNA (g protein/day) = [(NUU (g)) + (0.031 g N/kg)] × 6.25
Where:
NUU = urinary urea nitrogen x [urinary urea (g/L)/2.14] x urinary volume 24 h (L)
PNA final values are normalized by ideal or adjusted body weight*
  1. *Adjusted body weight should be calculated when actual body weight is lower than 95 % adequacy or higher than 115 % adequacy [12]