incremental AUC

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1

I am working with a dietary supplement that increases the systemic amount of several amino acids (aa) above baseline values. The analysis requires estimation of incremental AUC (AUCi) and net incremental AUC (net AUCi). I have a baseline value for the aa only, there is no threshold value. The drug effect (model 220) option in NCA allows the input of a baseline value and provides as output the parameters outlined below

AUC_Above_B
Area under the response curve that is above the baseline (dark gray areas in the above diagram).
AUC_Below_B
Area that is below the baseline and above the response curve (combined blue and pink areas in the above diagram).

Is AUC Above B equivalent to AUCi? Can net AUCi be estimated as

[AUCabove B] - [AUC below B]? See Figure 11 (c & e) in the attached paper discussing glycemic index for reference of what I am looking to estimate.

Glycemic_index_methodology.pdf (559 KB)

2

Graham,

the drug effect model in NCA calculates 3 values:

AUCnet.png
AUCnet.png1152×648 13.9 KB

Here:

AUC_Above_B accumulates all areas that are above the baseline, excluding any areas below the baseline

AUC_Below_B accumulates all areas that are below the baseline, excluding any areas above the baseline.

AUC_Net_B calculates the difference between these two values.

According to figures 11 c & e:

the black areas in figure 11 c) represents AUC_Above_B,

the white area between the two black areas in figure 11 c) represents AUC_Below_B

and figure 11 e) represents AUC_Net_B.

Hope, this makes sense. Let me know if there are further questions.

Bernd

3

Excellent, Thanks Bernd for the clarification