bodycompref

Calculate reference values for body composition

This R package allows batch calculation of reference values and derived metrics for skeletal muscle and subcutaneous and visceral adipose tissue. Please also refer to our website including additional information and a graphical representation: https://bodycomp-metrics.mgh.harvard.edu

Reference values are based on the following publications: Marquardt JP et al.(planned publication 2025; reserved doi: 10.1097/RLI.0000000000001104), "Subcutaneous and Visceral adipose tissue Reference Values from Framingham Heart Study Thoracic and Abdominal CT", Investigative Radiology and Tonnesen PE et al. (2023), "Muscle Reference Values from Thoracic and Abdominal CT for Sarcopenia Assessment [column] The Framingham Heart Study", Investigative Radiology, doi:10.1097/RLI.0000000000001012.

Installation

To download this package from GitHub, please use your standard method of installing non-CRAN packages. If you're installing packages from GitHub for the first time, you can try using the devtools package:

install.packages("devtools")

devtools::install_github("p-mq/bodycompref")

Usage

The package contains GAMLSS models to produce sex-, level-, metric-, and age-specific mappings of a measurement (raw value) to a corresponding z-score/percentile/percent of predicted value. With exception of percent predicted, the transformations are bidirectional.

You can use the same wrapper function (bodycomp_reference) for each transformation and specify the output or use the specific functions (reference_values, reference_percentiles, reference_z_scores, percent_predicted). See the vignette for quick start and the individual function documentation for further information.

Code tested for compatibility with R 4.4.0