Trunk-to-leg fat ratio may predict cardiometabolic risk in adolescents
A high trunk-to-leg fat ratio among adolescents may predict risks for developing several markers for cardiometabolic disease, including insulin resistance, high triglycerides and hypertension, according to findings published in Pediatric Obesity.
Previous studies suggest that children with a higher ratio of abdominal-to-peripheral fat deposition may be at greater risk for developing cardiometabolic disease, Catherine E. Cioffi, RD, a doctoral researcher in the department of nutrition and health services at Emory University Laney Graduate School, and colleagues wrote in the study background. Several studies examined the association using an android-to-gynoid fat ratio, researchers noted, with findings suggesting an association between that measure and cardiometabolic risk, although cohorts were small.
“Additionally, none of these pediatric studies used a ratio of truncal-to-leg fat, which has been associated with [cardiometabolic disease]-related outcomes [in] adults,” the researchers wrote.
Cioffi and colleagues analyzed data from 3,810 adolescents participating in the 2003-2004 and 2005-2006 cycles of the National Health and Nutrition Examination Survey (52% boys; 64.5% white; 19% with obesity). Participants underwent DXA measurements to assess total and regional body composition. Trunk-to-leg fat ratio was calculated with DXA data as trunk fat mass divided by the sum of left and right leg fat mass, multiplied by 100.
Researchers determined cardiometabolic disease risk factors from blood samples and physical exams and used linear and logistic regression analyses adjusted for BMI z score to examine associations between trunk-to-leg fat ratio and cardiometabolic disease risk factors.
In sex-stratified logistic regression analyses, researchers found that, for boys, each standard deviation increase in log-transformed trunk-to-leg fat ratio was associated with increased odds for high homeostatic model assessment of insulin resistance (HOMA-IR; OR = 2; 95% CI, 1.4-2.9), high triglycerides (OR = 2.6; 95% CI, 1.6-4.4), low HDL cholesterol (OR = 1.6; 95% CI, 1.3-2.2), high total cholesterol (OR = 1.5; 95% CI, 1.1-2) and high blood pressure (OR = 2.5; 95% CI, 1.3-3.6).
Similarly, in girls, each standard deviation increase in log-transformed trunk-to-leg fat ratio was associated with increased odds for high HOMA-IR (OR = 1.9; 95% CI, 2.6-3.6), high triglycerides (OR = 1.5; 95% CI, 1.1-2.3), low HDL cholesterol (OR = 1.8; 95% CI, 1.3-2.4), high total cholesterol (OR = 1.5; 95% CI, 1.1-2.1) and high BP (OR = 1.7; 95% CI, 1.2-2.5).
In analyses further stratified by race, researchers found that trunk-to-leg fat ratio was positively associated with high triglycerides, total cholesterol and alanine aminotransferase for white and Mexican-American participants (P < .05), but not black participants. Associations between trunk-to-leg fat ratio and HOMA-IR and HDL cholesterol were significant for all races/ethnicities, according to researchers.
Researchers did not observe any association between trunk-to-leg fat ratio and fasting plasma glucose or HbA1c measures in participants.
“Collectively, these findings confirm prior research suggesting that body fat distribution is an independent correlate of certain measures of metabolic dysfunction in adolescents and show that [trunk-to-leg fat ratio] may be able to predict which children are at greater risk of cardiometabolic dysfunction, regardless of their overall weight status,” the researchers wrote. “This has important implications for health care professionals who are screening pediatric patients for [cardiometabolic disease] risk.”
The researchers further noted that trunk-to-leg fat ratio was more consistently associated with cardiometabolic disease risk when compared with waist circumference, in particular among white and Mexican-American participants. However, waist circumference may be an “adequate and affordable alternative” for assessing cardiometabolic risk factors while additional research examines accurate surrogates for trunk-to-leg fat ratio. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.