calc_ffm: Calculate fat-free mass

In InsightRX/clinPK: Clinical Pharmacokinetics Toolkit

Calculate fat-free mass

Description

Get an estimate of fat-free mass (FFM, in kg) based on weight, height, and sex (and age for Storset equation).

Usage

calc_ffm(
  weight = NULL,
  bmi = NULL,
  sex = NULL,
  height = NULL,
  age = NULL,
  method = c("janmahasatian", "green", "al-sallami", "storset", "bucaloiu", "hume",
    "james", "garrow_webster"),
  digits = 1
)

Arguments

weight	total body weight in kg
bmi	BMI, only used in green method. If weight and height are both specified, bmi will be calculated on-the-fly.
sex	sex, either male of female
height	height in cm, only required for holford method, can be used instead of bmi for green method
age	age, only used for Storset equation
method	estimation method, one of janmahasatian (default), green, al-sallami, storset, bucaloiu, hume, james, or garrow_webster.
digits	round to number of digits

Details

References: janmahasatian, green: Janmahasatian et al. Clin Pharmacokinet. 2005;44(10):1051-65) al-sallami: Al-Sallami et al. Clin Pharmacokinet 2015 storset: Storset E et al. TDM 2016 bucaloiu: Bucaloiu ID et al. Int J of Nephrol Renovascular Dis. 2011 (Morbidly obese females) hume: Hume R. J Clin Pathol 1966 james: James WPT et al. Research on obesity: a report of the DHSS/MRC Group 1976 garrow_webster: Garrow JS, Webster J. Quetelet's index (W/H2) as a measure of fatness. Int J Obesity 1984

Overview:

• Sinha J, Duffull1 SB, Al-Sallami HS. Clin Pharmacokinet 2018. https://doi.org/10.1007/s40262-017-0622-5

Value

Returns a list of the following elements:

value	Fat-free Mass (FFM) in units of kg
unit	Unit describing FFM, (kg)
method	Method used to calculate FFF

Examples

calc_ffm(weight = 70, bmi = 25, sex = "male")
calc_ffm(weight = 70, height = 180, age = 40, sex = "female", method = "storset")

InsightRX/clinPK documentation built on June 14, 2025, 9:48 p.m.