Classification of childhood obesity using longitudinal clinical body mass index and its validation

Area of Science:

• Pediatric Endocrinology
• Cardiovascular Health
• Obesity Research

Background:

• Childhood adiposity is linked to long-term cardiometabolic risks.
• Current obesity classification relies on cross-sectional Body Mass Index (BMI) percentiles.
• A more dynamic classification is needed to capture persistent obesity and associated risks.

Purpose of the Study:

• To develop and validate a longitudinal BMI classification system for children.
• To assess the association of this new classification with early-onset obesity, socioeconomic status, and cardiometabolic risk.
• To compare the predictive power of longitudinal versus cross-sectional BMI for cardiometabolic risk.

Main Methods:

• Utilized electronic health record data from a large tertiary care hospital and an independent cohort.
• Employed median BMI percentile and persistence in obesity class for longitudinal classification (≥ 3 BMI measurements).
• Analyzed associations between longitudinal BMI class, early obesity, socioeconomic status (SES), and cardiometabolic risk indicators.

Main Results:

• Obesity (BMI ≥ 95th percentile) affected 24.1% and severe obesity 10.6% of children.
• Early-onset obesity (≤ 6 years) often persisted, with higher SES linked to lower obesity odds.
• Longitudinal BMI classification demonstrated superior prediction of cardiometabolic risk (AUC 80.0%) compared to cross-sectional BMI (75.8%).

Conclusions:

• Longitudinal BMI classification offers a more accurate reflection of children's long-term cardiometabolic risk.
• This refined classification can guide focused interventions and identify children for genetic risk profiling.
• The findings support a shift towards dynamic BMI assessment in pediatric obesity management.