Commonly Used Equations for Estimating Lean Body Weight are Inaccurate

Abstract

Empiric equations used to estimate lean body weight (LBW) were published in 1974 by Devine. In an attempt to validate these equations, linear regression equations using the 1959 Metropolitan Life Insurance Company (MTL-59) height and weight tables were developed. However, the tables were updated in 1983 (MTL-83) with different weights, with some values as much as 17% higher. This study's purpose was to determine if the regression equations had changed. The results demonstrate that the linear relationship between height and weight is not as strong with the 1983 table values. In addition, two LBW equations indicate that the weight values reported in 1983 overestimate LBW by 7 to 13 kg. These data indicate that the Devine formulas for estimating LBW may in reality be estimating “average” weight for height. A call is made for future studies that test whether estimating LBW according to population-specific formulas leads to a more accurate representation of the clinical pharmacokinetics of drugs.