Lean body mass

:LBM + BF = BW ::Lean body mass plus body fat equals body weight LBM differs from FFM in that cellular membranes are included in LBM although this is only a small percent difference in the body's mass (up to 3% in men and 5% in women) ## Overview The percentage of total body mass that is lean is usually not quoted – it would typically be 60–90%. Instead, the body fat percentage, which is the complement, is computed, and is typically 10–40%. The lean body mass (LBM) has been described as an index superior to total body weight for prescribing proper levels of medications and for assessing metabolic disorders, as body fat is less relevant for metabolism. LBW is used by anesthesiologists to dose certain medications. For example, due to the concern of postoperative opioid-induced ventilatory depression in the obese patient, opioids are best based on lean body weight. The induction dose of propofol should also be based on LBW. ## Estimation LBM is usually estimated using mathematical formulas. Several formulas exist, having different utility for different purposes. For example, the Boer formula is method of choice for LBM estimation to calculate the dose given in contrast CT in obese individuals with BMI between 35 and 40. A nomogram based on height, weight and arm circumference may be used. ### Boer The Boer formula is: For men: LBM = (0.407 × W) + (0.267 × H) − 19.2 For women: LBM = (0.252 × W) + (0.473 × H) − 48.3 where W is body weight in kilograms and H is body height in centimeters. ### Hume The following formula by Hume may be used: For men: LBM = (0.32810 × W) + (0.33929 × H) − 29.5336 For women: LBM = (0.29569 × W) + (0.41813 × H) − 43.2933 where W is body weight in kilograms and H is body height in centimeters. ## Actual measurement Instead of mathematical estimation the actual value of LBM may be calculated using various technologies such as Dual-energy X-ray absorptiometry (DEXA). ## References ## References 1. (14 October 2013). "Lean body mass: the development and validation of prediction equations in healthy adults.". *BMC Pharmacology & Toxicology*. 2. ''Stoelting's Anesthesia and Co-Existing Disease, 6th Edition. Pages 329-330.'' 3. (13 August 2018). "Lean Body Weight-Tailored Iodinated Contrast Injection in Obese Patient: Boer versus James Formula". *[[BioMed Research International]]*. 4. Fuchs, RJ. (1 April 1978). "A nomogram to predict lean body mass in men.". *[[The American Journal of Clinical Nutrition]]*. 5. Hume, R. (Jul 1966). "Prediction of lean body mass from height and weight.". *[[Journal of Clinical Pathology]]*. ::callout[type=info title="Wikipedia Source"] This article was imported from [Wikipedia](https://en.wikipedia.org/wiki/Lean_body_mass) and is available under the [Creative Commons Attribution-ShareAlike 4.0 License](https://creativecommons.org/licenses/by-sa/4.0/). Content has been adapted to SurfDoc format. Original contributors can be found on the [article history page](https://en.wikipedia.org/wiki/Lean_body_mass?action=history). ::