273 - Excess adiposity in children with normal weight is associated with increased liver and visceral adipose tissue deposition

Publication Number: 273.4957

Jonathan P. Bennett, University of Hawaii Cancer Center, Honolulu, HI, United States; Nisa Kelly, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; En Liu, University of Hawaii, John A. Burns School of Medicine, Honolulu, HI, United States; Sophia E. Ramirez, Pennington Biomedical Research Center, Baton, LA, United States; Brandon Quon, University of Hawaii Cancer Center, Honolulu, HI, United States; Steven D. Buchthal, University of Hawaii Cancer Center, Honolulu, HI, United States; Andrea K. Garber, University of California, San Francisco, School of Medicine, San Francisco, CA, United States; Steven B.. Heymsfield, Pennington Biomedical, Baton Rouge, LA, United States; John A. Shepherd, University of Hawaii, Honolulu, HI, United States

Background: In pediatric clinical practice, a normal weight (based on BMI Z-score) is associated with reduced disease risk. However, body composition assessment plays an essential role in monitoring factors such as overall fat mass and distribution, which may be considered high risk even in “normal weight” children and adolescents.

Objective: To explore whether increased overall adiposity in children classified as normal weight based on BMI is associated with ectopic fat storage.

Design/Methods: The cross-sectional Shape Up! Kids study was conducted among children aged 5-17 years, stratified by sex, age, race/ethnicity, and geographic location (Honolulu, HI and Baton Rouge, LA). Subjects were assessed by anthropometry, whole-body and visceral adipose tissue (VAT) composition by dual energy X-ray absorptiometry (DXA), and liver and VAT (at the L4/L5 vertebrae) by magnetic resonance imaging (MRI). Normal weight was defined as BMI < 85th percentile for height and gender. Excess fat was determined by DXA using percent body fat (BF%) thresholds of ≥20% for boys and ≥30% for girls (1).

Results: A total of 235 children (126 female; age= 12.3 ± 3.6y, had normal weight based on BMI percentile (48.6 ± 25.0%). Based on DXA results, 66 (28.1%) of children were classified as above sex-specific BF% thresholds. As shown in Table 1, those with elevated BF% had significantly greater VAT area (35.0 ± 12.2cm2 vs. 24.7 ± 11.3cm2, p < 0.001) compared to those with normal BF%. In the sample with available MRI data (n = 199, 101 female), children with increased BF% had higher average percent liver fat (2.4 ± 0.6% vs. 2.2 ± 0.5%, p < 0.05) and VAT area (31.0 ± 11.0cm2 vs. 24.8 ± 11.0cm2, p < 0.01) compared to those with normal BF%.

Conclusion(s): These results show that increased adiposity, regardless of BMI percentile, is associated with increased ectopic fat deposition in the liver and visceral cavity as assessed by DXA or MRI. These findings support the importance of body composition assessment in clinical practice to prevent the accumulation of ectopic fat stores associated with increased cardiovascular disease risk.

Differences in visceral adipose tissue or liver fat between children with normal weight and normal or excess body fat percentage*
† p < 0.001, ‡ p < 0.01, ⸸ p < 0.05 compared to normal BF%
*Body fat percentage defined as ≥20% for boys and ≥30% for girls
Abbreviations: DXA: dual energy X-ray absorptiometry, MRI: magnetic resonance imaging, VAT: visceral adipose tissue