DOBToPDR: Convert DOB to PDR

In dmenne/d13cbreath: Reads and Evaluates Gastric Emptying 13C Breath Test Data

Description

Convert DOB to PDR for 13C breath test. This is equation (4) in Sanaka, Yamamoto, Tsutsumi, Abe, Kuyama (2005) Wagner-Nelson method for analysing the atypical double-peaked [13CO2] excretion curve in the [13C]-octanoate gastric emptying breath test in humans. Clinical and Experimental Pharmacology and Physiology 32, 590-594.

Usage

DOBToPDR(DOB, weight = 75, height = 180, MW = 167,
  purityPercent = 99.1, mgSubstrate = 100)

Arguments

DOB	vector in 0/00
weight	body weight in kg; assumed 75 kg if missing
height	body height in cm; assume 180 cm if missing
MW	Molecular weight, 83.023388 g/mol for acetate, 167 g/mol for octanoate. Can also be given as string "acetate" or "octanoate".
purityPercent	purity in percent
mgSubstrate	substrate in mg

Value

PDR percent dose/h

Note

I have no idea where the factor 10 in equation (4) comes from, possibly from percent(PDR)/and DOB(0/00). In Kim and Camillieri, Stable Isotope Breath Test and Gastric Emptying, page 207 a factor of 0.1123 instead of 0.01123 is used, without the factor 10. Which one is correct?

Author(s)

Dieter Menne, [e-mail]

Examples

filename = system.file("extdata/extrasample", "350_20049_0_GERWithWeight.txt",
    package = "D13CBreath")
bid = ReadBreathId(filename)
bid$Data$PDR1 = DOBToPDR(bid$Data$DOB,weight=bid$Weight,height=bid$Height)

plot(bid$Data$Time, bid$Data$PDR1,main="Points: From BreathID; line: computed",type="l")
points(bid$Data$Time, bid$Data$PDR,col="red",type="p",pch=16)
var(bid$Data$PDR1-bid$Data$PDR)

dmenne/d13cbreath documentation built on March 1, 2020, 3:41 a.m.