Body Mass Index as a measure of bone mass

Abstract
Introduction: BMI is an indicator of body composition (BC) and adiposity in particular. This status is the result of good correlations with indirect (e.g. predictive) two- and three-component models predicting body fat.
Purpose: To measure the direct relation of BMI with total and segmental BC, e.g. of skin, muscle, bone, viscera and adipose tissue.
Methods: BC constituents of 29 white elderly persons (17 females and 12 males, aged 78.1 ±6.9 years) were determined by direct dissection. Correlations and stepwise linear regression analysis with BMI (dependent variable) and all BC constituents (independent variables) were calculated.
Results: All tissues dissected indicated a too high unexplained variance except for bone that accounted for 84% of BMI variance in females and 61% in males (pConclusion: The BMI cannot be an appropriate adiposity index. The high proportion of unexplained variance between BMI and direct BC constituents limit its use as a whole body and as a segmental BC index. The BMI could be an index for Bone Mass instead.