Development and Application of Children's Sex- and Age-Specific Fat-Mass and Muscle-Mass Reference Curves From...

Area of Science:

• Pediatric endocrinology
• Body composition analysis
• Cardiometabolic health

Background:

• Dual-energy x-ray absorptiometry (DXA) derived phenotypes for adults based on fat and muscle mass exist.
• This classification was extended to a pediatric population for the first time.

Purpose of the Study:

• To adapt and validate a DXA-derived phenotype classification for children.
• To assess the association of these pediatric phenotypes with cardiometabolic risk.

Main Methods:

• Utilized NHANES data (n=6120) to create sex- and age-specific deciles for appendicular skeletal muscle mass index and fat mass index.
• Defined four phenotypes (HA-HM, HA-LM, LA-HM, LA-LM) based on median comparisons.
• Applied these phenotypes to the QUALITY cohort (n=630) to evaluate cardiometabolic risk at baseline and follow-up using regression models.

Main Results:

• The high adiposity-high muscle mass (HA-HM) phenotype showed less favorable HDL, triglycerides, and HOMA-IR compared to the low adiposity-high muscle mass (LA-HM) group.
• The high adiposity-low muscle mass (HA-LM) phenotype was linked to less favorable HOMA-IR at both baseline and follow-up.

Conclusions:

• Pediatric phenotypes based on fat and muscle mass show potential clinical utility.
• Further investigation into these DXA-derived phenotypes for children is warranted.