Background

Clinicians lack guidance for classifying children less than 2 years of age as obese or for identifying infants or young children at highest risk for obesity. There is a paucity of longitudinal growth data in diverse populations of infants. Therefore, we aimed to analyze growth in infants and the relationship of obesity during infancy with obesity at 2 years of age.

Methods

We extracted weight, height/length, age, insurance status, and demographics from the Carolinas Collaborative Data Model (CCDM) among patients born on or after 1/1/2013. The CCDM is a repository of electronic health record (EHR) data from 4 institutions in North and South Carolina. We calculated BMI and describe the prevalence of overweight (BMI 85th to <95th percentile) and obesity (BMI ≥95th percentile) at birth and at 6, 12, and 24 months. We used separate logistic regression models to assess the odds of obesity at 2 years based on weight status at birth, 6, and 12 months, adjusting for sex and site. Race/ethnicity and insurance were not significant predictors and were not included in the final model.

Results

Patients were 53.2% male (N=106,159). Prevalence of overweight and obesity were 4.9% and 3.3% at birth (N=44,555), 10.7% and 9.3% at 6 months (N=46,684), 16.2% and 16.9% at 12 months (N=39,272), and 17.1% and 21.3% at 2 years, respectively.Overweight and obesity during infancy were increasingly predictive of obesity at 2 years. At 6 months overweight and obesity were associated with 3.8 (95% CI 4.7, 8.4) and 6.3 times the odds (4.7, 8.4) of obesity at 2 years and at 12 months the odds were even greater (OR 4.4 [3.4, 5.6]) and (10.2 [8.1, 13.0]).

Conclusions

Overweight and obesity throughout infancy predicts obesity at 2 years of age, with stronger associations found with increasing weight status and age.Clinicians can use this information when counseling families about weight status during infancy, and should consider intervening to decrease weight status during infancy.