insulin.secretion (version 0.0.2)

isr.deconv: Insulin Secretion Rate Deconvolution

Description

Estimates insulin secretion rate based on a time series of c-peptide values based on the Van Cauter method. C-peptide values are interpolated using either linear approximation or a cubic spline; the linear method (default) will output a time series of insulin secretory rates at time points between each input time, whereas the spline method will output a function which can be called to return insulin secretory rates for specific time points.

Typically, c-peptide values are provided in pmol/mL and time is in minutes, resulting in insulin secretion rate outputs in pmol/min.

Although this function was designed with insulin secretion in mind, it uses a two-compartment secretion model that may be applied beyond insulin.

Usage

isr.deconv(
  timeseries,
  cpepseries,
  vol,
  shl,
  lhl,
  frc,
  method = c("linear", "spline"),
  plotspline = FALSE,
  plotisr = FALSE,
  isr.validated.vals,
  isr.validated.time
)

Value

If method = "linear" is selected (default), returns a list of time points and insulin secretory rates. If method = "spline" is selected, returns a function which can be called to return insulin secretory rates at specified time points.

Arguments

timeseries

Vector of numeric time values corresponding to the c-peptide values in cpepseries

cpepseries

Vector of numeric c-peptide values at each time point in timeseries

vol

Volume of distribution in the main compartment (i.e., serum volume), which can be calculated with the isr.volume() function

shl

Short half-life, which can be calculated with the isr.shortHL() function

lhl

Long half-life, which can be calculated with the isr.longHL() function

frc

Fraction attributable to the short half-life, which can be calculated with the isr.fraction() function

method

Determines whether C-peptide values are interpolated with linear connections between the points or a cubic spline

plotspline

Dictates whether to print a plot of the C-peptide interpolation

plotisr

Dictates whether to print a plot of the ISR output values

isr.validated.vals

Used for debugging; validated ISR values to compare to past analyses

isr.validated.time

Used for debugging; time values corresponding to validated ISR values to compare to past analyses

See Also

isr.volume(), isr.shortHL(), isr.longHL(), isr.fraction()

Examples

isr.deconv(
  timeseries = c(-30, 0, 30, 60, 90, 120),
  cpepseries = c(1.72, 1.72, 5.40, 5.23, 2.71, 1.79),
  vol = 6104,
  shl = 4.55,
  lhl = 31.05,
  frc = 0.78,
  method = "linear",
  plotspline = TRUE,
  plotisr = TRUE,
)