Emily Nagel1,2, Christopher Desjardins3, Carrie Earthman4, Sara Ramel5, Ellen Demerath2. 1. Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA. 2. School of Public Health, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA. 3. Department of Mathematics and Statistics, St. Michael's College, Colchester, Vermont, USA. 4. Department of Behavioral Health and Nutrition, University of Delaware, Newark, Delaware, USA. 5. Department of Pediatrics, University of Minnesota-Twin Cities, Minneapolis, Minnesota, USA.
Abstract
BACKGROUND: Weight/length (W/L) indices are poor surrogates for adiposity in preterm infants born appropriate for gestational age (AGA) at birth, but whether the association subsequently improves is unknown. OBJECTIVE: To determine if W/L indices accurately reflect adiposity in premature infants born AGA in later infancy. METHODS: Associations between W/L indices and fat mass, fat mass index and percent body fat (%BF) obtained via air displacement plethysmography (ADP) were examined in 260 preterm infants (majority born AGA) at 28 to 63 weeks' postmenstrual age (PMA). Accuracy of W/L indices as indicators of adiposity was assessed by proportion of variance explained (R2 ) and root mean square error from linear regression of adiposity on W/L indices and proportion of infants misclassified by W/L indices. Accuracy was further compared in term vs preterm infants at term-equivalent age. The impact of early vs late preterm status on associations between W/L indices and %BF was also examined. RESULTS: BMI and W/L were most strongly associated with %BF but yielded poorly fitting models (maximum R2 = 0.35; 53% misclassification). A significant interaction of W/L indices and early vs late preterm status on %BF revealed that estimation of %BF differs by status. Accuracy of W/L indices was worse in preterm infants at term-equivalent age. CONCLUSIONS: W/L indices were not good indicators of adiposity in preterm infants from 28 to 63 weeks' PMA (born AGA) with all categories of W/L indices combined. Future research should examine whether results are similar in preterm infants born with disproportionate W/L or who experience disproportionate growth postnatally.
BACKGROUND: Weight/length (W/L) indices are poor surrogates for adiposity in preterm infants born appropriate for gestational age (AGA) at birth, but whether the association subsequently improves is unknown. OBJECTIVE: To determine if W/L indices accurately reflect adiposity in premature infants born AGA in later infancy. METHODS: Associations between W/L indices and fat mass, fat mass index and percent body fat (%BF) obtained via air displacement plethysmography (ADP) were examined in 260 preterm infants (majority born AGA) at 28 to 63 weeks' postmenstrual age (PMA). Accuracy of W/L indices as indicators of adiposity was assessed by proportion of variance explained (R2 ) and root mean square error from linear regression of adiposity on W/L indices and proportion of infants misclassified by W/L indices. Accuracy was further compared in term vs preterm infants at term-equivalent age. The impact of early vs late preterm status on associations between W/L indices and %BF was also examined. RESULTS: BMI and W/L were most strongly associated with %BF but yielded poorly fitting models (maximum R2 = 0.35; 53% misclassification). A significant interaction of W/L indices and early vs late preterm status on %BF revealed that estimation of %BF differs by status. Accuracy of W/L indices was worse in preterm infants at term-equivalent age. CONCLUSIONS: W/L indices were not good indicators of adiposity in preterm infants from 28 to 63 weeks' PMA (born AGA) with all categories of W/L indices combined. Future research should examine whether results are similar in preterm infants born with disproportionate W/L or who experience disproportionate growth postnatally.
Authors: Caterina Coviello; Kristin Keunen; Karina J Kersbergen; Floris Groenendaal; Alexander Leemans; Barbara Peels; Ivana Isgum; Max A Viergever; Linda S de Vries; Giuseppe Buonocore; Virgilio P Carnielli; Manon J N L Benders Journal: Pediatr Res Date: 2017-10-25 Impact factor: 3.756
Authors: Katie M Pfister; Lei Zhang; Neely C Miller; Ellen C Ingolfsland; Ellen W Demerath; Sara E Ramel Journal: Pediatr Res Date: 2018-08-21 Impact factor: 3.756
Authors: Izzuddin M Aris; Sheryl L Rifas-Shiman; Ling-Jun Li; Seungmi Yang; Mandy B Belfort; Jennifer Thompson; Marie-France Hivert; Rita Patel; Richard M Martin; Michael S Kramer; Emily Oken Journal: JAMA Netw Open Date: 2018-09-07
Authors: Katherine A Bell; Sara E Ramel; Daniel T Robinson; Carol L Wagner; Brian Scottoline; Mandy B Belfort Journal: J Perinatol Date: 2022-10-06 Impact factor: 3.225