Underweight in the First 2 Years of Life and Growth in Later Childhood

• Published in: JAMA network open Vol. 5; no. 7; p. e2224417
• Main Authors: South, Courtney A., Keown-Stoneman, Charles D. G., Birken, Catherine S., Malik, Vasanti S., Zlotkin, Stanley H., Maguire, Jonathon L., Birken, Catherine, Maguire, Jonathon, Allen, Christopher, Anderson, Laura, Arafeh, Dana, Jaleel, Mateenah, Keown-Stoneman, Charles, Levy McFarlane, Natricha, Omand, Jessica, Aglipay, Mary, Bayoumi, Imaan, Borkhoff, Cornelia, Carsley, Sarah, Cost, Katherine, D'Hollander, Curtis, Fuller, Anne, Kinlin, Laura, Li, Patricia, Parkin, Pat, Persaud, Nav, Socynska, Izabela, Vanderhout, Shelley, Vanderloo, Leigh, Wong, Peter, Li, Xuedi, Mitchell, Michelle, Shaibu, Hakimat, Yoshida-Montezuma, Yulika, Bustos, Marivic, Flores, Pamela Ruth, Ogwuru, Martin, Thadani, Sharon, Thompson, Julia, Thompson, Laurie, Kurt, Kardelen, Malick, Ataat, Batten, Jennifer, Chan, Jennifer, Clark, John, Colford, Maureen, Craig, Amy, De Castris-Garcia, Kim, Dharman, Sharon, Garcia, Anthony, Kelleher, Sarah, Marquez, Sandra, Nasser, Salimah, Pabon, Tammara, Rhodes, Michelle, Salsa, Rafael, Shin, Jia, Skelding, Julie, Stern, Daniel, Stewart, Kerry, Sendra Tavares, Erika, Weir, Shannon, Zaccaria, Maria, Janus, Magdalena, Duku, Eric, Reid-Westoby, Caroline, Raso, Patricia, Offord, Amanda, Abraham, Emy, Ali, Sara, Anderson, Kelly, Arbess, Gordon, Baker, Jillian, Barozzino, Tony, Bergeron, Sylvie, Bloch, Gary, Bonifacio, Joey, Bowry, Ashna, Calpin, Caroline, Campbell, Douglas, Cheema, Sohail, Cheng, Elaine, Chisamore, Brian, Constantin, Evelyn, Danayan, Karoon, Das, Paul, De Guerra, Viveka, Derocher, Mary Beth, Do, Anh, Doukas, Kathleen, Egger, Anne, Farber, Allison, Freedman, Amy, Freeman, Sloane, Gazeley, Sharon, Grewal, Karen, Guiang, Charlie, Ha, Dan, Handford, Curtis, Hanson, Laura
• Format: Journal Article
• Language: English
• Published: Chicago American Medical Association 29.07.2022
• Subjects: Children & youth; Cohort analysis; Online Only; Original Investigation; Pediatrics
• ISSN: 2574-3805; 2574-3805
• DOI: 10.1001/jamanetworkopen.2022.24417

Importance Few studies have examined the association between underweight in the first 2 years and growth in later childhood in high-income countries. Objective To evaluate the associations of underweight in the first 2 years of life with body mass index (calculated as weight in kilograms divided by height in meters squared)zscore (zBMI), weight-for-agezscore (WAZ), and height-for-agezscore (HAZ) from ages 2 to 10 years. Design, Setting, and Participants This prospective cohort study was conducted between February 2008 to September 2020 in The Applied Research Group for Kids! practice-based research network in Toronto, Canada. Participants included healthy children aged 0 to 10 years. Data were analyzed from October 2020 to December 2021. Exposures Underweight (ie, zBMI less than −2, per the World Health Organization) in the first 2 years of life. Main Outcomes and Measures The primary outcome was zBMI from ages 2 to 10 years. Linear mixed-effects models were used to account for multiple growth measures over time. Results A total of 5803 children were included in the primary analysis. At baseline, the mean (SD) age was 4.07 (5.62) months, 2982 (52.2%) were boys, and 550 children (9.5%) were underweight. Underweight in the first 2 years was associated with lower zBMI (difference, −0.39 [95% CI, −0.48 to −0.31]) at 10 years and lower HAZ (difference, −0.24 [95% CI, −0.34 to −0.14]) at age 2 years. Stratified by sex, at age 10 years, girls and boys with underweight in the first 2 years both had lower zBMI (girls: difference, −0.47 [95% CI, −0.59 to −0.34]; boys: difference, −0.32 [95% CI, −0.44 to −0.20]). At age 10 years, children with underweight and a lower zBMI growth rate in the first 2 years had lower zBMI (difference, −0.64 [95% CI, −0.77 to −0.53) and HAZ (difference, −0.12 [−0.24 to −0.01]), while children with underweight and a higher zBMI growth rate in the first 2 years had similar zBMI (difference, −0.11 [95% CI, −0.22 to 0.001]) and higher HAZ (difference, 0.16 [95% CI, 0.05 to 0.27]) compared with children who did not have underweight in the first 2 years. Conclusions and Relevance In this prospective cohort study, children with underweight in the first 2 years of life had lower zBMI and HAZ in later childhood. These associations were attenuated among children with a higher growth rate in the first 2 years.