Body fat and fat-free mass normalization by height. (

RODRÍGUEZ P, ; BERMÚDEZ E, ; MACRI E, ; PONCE G, ; JUIZ N, ; ZENI SN, ; EXENI R, ; FRIEDMAN S.

New Orleans

Congreso; Annual Meeting of Experimental Biology Society; 2009

FASEB

Measurement of children´s body composition has become increasingly common. However, attention has been focused on methods, and less on the way in which data is expressed. Objective: to study the relationship between height (Ht) with fat mass (FM) and fat-free mass (FFM), measured by DXA in preschool children; and calculate an independent index (FMI and FFMI) of Ht. Seventy five children (males= 31, females= 44) aged 3 to 5, from La Matanza, Province of Buenos Aires, Argentina, attending a day care center, were included. There were healthy according to anthropometric (WHO, 1999) and clinical evaluation. Ht data were collected and FM and FFM were measured using a Lunar DPX-L, pediatric software. Pearson´s correlation was used to examine the association between FM, FFM, FMI and FFMI with Ht, and linear regression to determine what power of height (Hty) results in a zero correlation between body composition and Ht. Results: FM and FFM are associated with Ht (p=0.0222 and p< 0.0001, respectively) without differences between sexes. The slope of the regression line relating lgFM to lgHt was 1.49, while that for lgFFM to lgHt was 2.12. Thus, FM/Ht and FFM/Ht2 are uncorrelated with Ht (p=0.4063 and p=0.3695, respectively). Conclusion: to compare children´s body composition, normalization for body size is required. The indices FMI (FM/Ht) and FFMI (FFM/Ht2) would be appropriate for this purpose. Awarded by UBACyT O-008 and 015.