Date of Award

2011-01-01

Degree Name

Master in Public Health

Department

Public Health

Advisor(s)

Chantal Vella

Second Advisor

Joe Tomaka

Abstract

Introduction: The purpose of this study was to evaluate whether central (visceral) fat measured as waist circumference and daily fructose intake were associated with measures of non-alcoholic fatty liver disease (NAFLD) in Hispanic overweight adolescents.

Methodology: Thirty four obese boys (n=15) and girls (n=19) between the ages of 13 and 18 years were measured for body composition, waist circumference, and dietary fructose intake. Fasting alanine (ALT) and aspartate (AST) aminotransferase levels in blood, ALT/AST ratio, and hepatic fat fraction (HFF) by magnetic resonance imaging were measured and used as surrogates for NAFLD. Pearson Product-Moment correlation analyses were used to assess correlations between variables. Linear regression models were created to examine independent correlations after controlling for the covariates age, sex, and body mass index (BMI).

Results: Overall, 26% of participants had fatty liver (HFF > 5.5%) compared to 20% of boys and 32% of girls, however, differences were not significant (χ2 (1) = 0.57, p = 0.47). All but one participant had normal ALT and AST levels in blood (< 40 U/L). An ALT/AST ratio > 1.0 was seen in 44% of all participants. Statistically significant correlations included age and log ALT/AST (r = 0.42, p < 0.05), fat mass (r = 0.63, p < 0.01), fat-free mass (r = 0.80, p < 0.01); sex (1=male, 2=female) and BMI (r = 0.36, p < 0.05), log HFF (r = 0.37, p < 0.05), total caloric intake (r = -0.36, p < 0.05), fat mass (r = 0.36, p < 0.05), fat-free mass (r = –0.34, p < 0.05); fructose intake and total caloric intake (r = 0.48, p < 0.01); BMI and log HFF (r = 0.99, p < 0.01), log ALT/AST (r = 0.37, p < 0.05), fat mass (r = 0.80, p < 0.01), fat-free mass (r = –0.43, p < 0.01); log HFF and log ALT/AST (r = 0.40, p < 0.05), fat mass (r = 0.79, p < 0.01), fat-free mass (r = –0.45, p < 0.01); waist circumference and BMI (r = 0.62, p < 0.01), HFF (r = 0.65, p < 0.05), log ALT (r = 0.41, p < 0.05), log ALT/AST (r = 0.57, p < 0.01), fat mass (r = 0.53, p < 0.01), fat-free mass (r = 0.49, p < 0.01). In multivariate linear regression analysis, waist circumference was significantly associated with log HFF (β= 0.06, p < 0.01) and log ALT/AST (β= 0.49, p < 0.05), independent of age, sex, and BMI. Fructose intake was not significantly associated (p > 0.05) with log HFF (β= –0.05), log ALT (β= 0.19), log AST (β= 0.24) or log ALT/AST (β= 0.07), independent of total caloric intake.

Conclusion: The current study demonstrated that waist circumference, an indirect measure of central (visceral) fat, was significantly associated with log HFF and log ALT/AST, independent of age, sex, and BMI. Dietary fructose intake was not significantly associated with any of the measures of NAFLD. The prevention of obesity should be a primary intervention in children at risk for NAFLD.

Language

en

Provenance

Received from ProQuest

File Size

85 pages

File Format

application/pdf

Rights Holder

Hector Reyes

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