Objective: To correlate magnetic resonance imaging (MRI) of body fat in preterm infants at the time of hospital discharge with same-day anthropometric measures, and to assess the clinical utility of body mass index (BMI), waist circumference (WC), and WC/length ratio as indicators of visceral fat.
Study design: MRI performed prior to NICU discharge in 25 infants born preterm at <32 weeks gestation. Total body fat and visceral fat were quantified using a commercial software program. The Pearson correlation coefficient (r, 95% C.I.) was used to describe strength of association between MRI fat and anthropometric measures.
Results: BMI and weight at discharge were strongly correlated with total body fat (r = 0.95 and 0.89 respectively; p < 0.001). Total body fat as a % of body weight was moderately correlated with weight (r = 0.53), WC (r = 0.52), and BMI (r = 0.47). Weight, BMI, and ponderal index all were found to correlate with total visceral fat (r = 0.65, 0.64, 0.55 respectively) but WC did not (r = 0.28). WC/length ratio was not correlated with any MRI fat measurements.
Conclusions: BMI and weight at discharge both correlate with MRI fat measurements. Our findings do not support the usefulness of measuring WC or WC/length ratio in preterm infants at term-equivalent age.
Keywords: Anthropometric measures; body mass index; magnetic resonance imaging (MRI); prematurity.