Elsevier

The Journal of Pediatrics

Volume 162, Issue 6, June 2013, Pages 1160-1168.e1
The Journal of Pediatrics

Original Article
Alterations in Ventricular Structure and Function in Obese Adolescents with Nonalcoholic Fatty Liver Disease

https://doi.org/10.1016/j.jpeds.2012.11.024Get rights and content

Objective

To determine the association among nonalcoholic fatty liver disease (NAFLD), metabolic function, and cardiac function in obese adolescents.

Study design

Intrahepatic triglyceride (IHTG) content (magnetic resonance spectroscopy), insulin sensitivity and β-cell function (5-hour oral glucose tolerance test with mathematical modeling), and left ventricular function (speckle tracking echocardiography) were determined in 3 groups of age, sex, and Tanner matched adolescents: (1) lean (n = 14, body mass index [BMI] = 20 ± 2 kg/m2); (2) obese with normal (2.5%) IHTG content (n = 15, BMI = 35 ± 3 kg/m2); and (3) obese with increased (8.7%) IHTG content (n = 15, BMI = 37 ± 6 kg/m2).

Results

The disposition index (β-cell function) and insulin sensitivity index were ∼45% and ∼70% lower, respectively, and whole body insulin resistance, calculated by homeostasis model of assessment-insulin resistance (HOMA-IR), was ∼60% greater, in obese than in lean subjects, and ∼30% and ∼50% lower and ∼150% greater, respectively, in obese subjects with NAFLD than those without NAFLD (P < .05 for all). Left ventricular global longitudinal systolic strain and early diastolic strain rates were significantly decreased in obese than in lean subjects, and in obese subjects with NAFLD than those without NAFLD (P < .05 for all), and were independently associated with HOMA-IR (β = 0.634). IHTG content was the only significant independent determinant of insulin sensitivity index (β = −0.770), disposition index (β = −0.651), and HOMA-IR (β = 0.738).

Conclusions

These findings demonstrate that the presence of NAFLD in otherwise asymptomatic obese adolescents is an early marker of cardiac dysfunction.

Section snippets

Methods

Three groups of adolescents were studied: (1) lean (n = 14); (2) obese (BMI ≥95th percentile for age and sex19) with normal intrahepatic triglyceride (IHTG) content (<5.6% liver volume as triglyceride20; n = 15); and (3) obese with increased IHTG (NAFLD) (≥5.6% liver volume as triglyceride; n = 15). A comprehensive assessment was made of: (1) body composition, including body fat mass, abdominal fat distribution, and ectopic fat (IHTG, intracardiac triglyceride [ICTG], and skeletal muscle

Body Composition

Obese subjects with and without NAFLD were matched on BMI, BMI Z-score, and percent body fat (Table I). Intra-abdominal fat volume and IHTG content were greater in obese subjects with NAFLD than those without NAFLD. Although IHTG content was greater in obese subjects with NAFLD than those without NAFLD, IMTG and ICTG were not different between the 2 groups (Table I). Values for IHTG content correlated positively with percent body fat (r = 0.570, P < .001) and intra-abdominal fat volume (r =

Discussion

The presence of increased IHTG content is an important marker of metabolic dysfunction (multi-organ insulin resistance and dyslipidemia).5, 6 Our data demonstrate that obese adolescents with NAFLD have greater abnormalities in cardiac function, manifested by decreased systolic and diastolic myocardial strain and strain rate than obese adolescents who have normal IHTG content. The cardiac functional abnormalities in our obese adolescents with NAFLD were independent of traditional cardiac risk

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  • Cited by (0)

    Supported by National Institutes of Health (DK 37948, DK 56341 [Nutrition Obesity Research Center], and RR024992 [Clinical and Translational Science Award]). The authors declare no conflicts of interest.

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