Rationale and design of the Baylor Infant Twin Study (BITS) - A study assessing obesity-related risk factors from infancy

Authors: MOMIN, SHABNAM - Children'S Nutrition Research Center (CNRC); SENN, MACKENZIE - Children'S Nutrition Research Center (CNRC); BUCKLEY, SCOTT - Research Prototypes; BUIST, NEIL - Oregon Health & Science University; GANDHI, MANISHA - Texas Children'S Hospital; HAIR, AMY - Baylor College Of Medicine; HUGHES, SHERYL - Children'S Nutrition Research Center (CNRC); HODGES, KELLY - Baylor College Of Medicine; LANGE, WILLIAM - Indiana University; PAPAIOANNOU, MARIA - Children'S Nutrition Research Center (CNRC); PHAN, MIMI - Children'S Nutrition Research Center (CNRC); WATERLAND, ROBERT - Children'S Nutrition Research Center (CNRC); WOOD, ALEXIS - Children'S Nutrition Research Center (CNRC)

Submitted to: Obesity Science & Practice
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/4/2020
Publication Date: 10/8/2020
Citation: Momin, S.R., Senn, M.K., Buckley, S., Buist, N.R., Gandhi, M., Hair, A.B., Hughes, S.O., Hodges, K.R., Lange, W.C., Papaioannou, M.A., Phan, M., Waterland, R.A., Wood, A.C. 2020. Rationale and design of the Baylor Infant Twin Study (BITS) - A study assessing obesity-related risk factors from infancy. Obesity Science & Practice. https://doi.org/10.1002/osp4.463.
DOI: https://doi.org/10.1002/osp4.463

Interpretive Summary: During early childhood (0-3 years) tendencies in eating behaviors and physical activity are established. Therefore, this period is seen as a critical period for obesity prevention. Yet, little is understood about how children's behavioral tendencies develop in this time, with most research focusing on the preschool period (3-5 years of age) and beyond. To help us better understand the development of obesity-related behaviors in infancy, The Baylor Infant Twin Study (BITS) was instantiated in 2016. A unique aspect of BITS will be the inclusion of objective measures of feeding/eating and cognition in infants as young as four months old – measures for which little data on their reliability and validity exists. Due to the novelty of these objective measures, BITS is a two-phase study. During the first phase, for which data collection has been completed, three sub-studies were conducted to pilot the novel measures which will be used in the second phase. In the Behavior Observation Pilot Protocol (BOPP) study, a novel infant temperament assessment, based on observations made by trained researchers was piloted. In the Baylor Infant Orometer (BIO), a new device for measuring infant feeding parameters (the "orometer") was piloted, while EpiTwin developed and tested methods for analyzing DNA methylation in twins of unknown chorionicity. EpiTwin was a cross-sectional study of neonatal twins, while up to three study visits occurred for the other studies, at 4- (BOPP, BIO), 6- (BOPP) and 12- (BOPP, BIO) of age. Measurements for BOPP and BIO included temperament observations, feeding observations, and body composition assessments while EpiTwin focused on collecting samples of hair, urine, nails and blood for quantifying methylation levels at 10 metastable epialleles. Additional data collected include demographic information, zygosity, chorionicity and questionnaire-based measures of infant behaviors. Recruitment for all three studies was completed in early 2020. EpiTwin recruited 80 twin pairs (50% monochorionic), 31 twin pairs completed the BOPP protocol, and 68 singleton infants participated in BIO. The psychometric properties of the data from all three studies are being analyzed currently. The resulting findings will inform the development of the full BITS protocol, with the goal of completing assessments at 4-, 6-. 12- and 14- months of age for 400 twin pairs.

Technical Abstract: Early childhood (0-3 years) is a critical period for obesity prevention, when tendencies in eating behaviors and physical activity are established. Yet, little is understood about how the environment shapes children's genetic predisposition for these behaviors during this time. The Baylor Infant Twin Study (BITS) is a two phase study, initiated to study obesity risk factors from infancy. Data collection has been completed for Phase 1 in which three sub-studies pilot central measures for Phase 2. A novel infant temperament assessment, based on observations made by trained researchers was piloted in Behavior Observation Pilot Protocol (BOPP) study, a new device for measuring infant feeding parameters (the "orometer") in the Baylor Infant Orometer (BIO), and methods for analyzing DNA methylation in twins of unknown chorionicity in EpiTwin. EpiTwin was a cross-sectional study of neonatal twins, while up to three study visits occurred for the other studies, at 4- (BOPP, BIO), 6- (BOPP) and 12- (BOPP, BIO) of age. Measurements for BOPP and BIO included temperament observations, feeding observations, and body composition assessments while EpiTwin focused on collecting samples of hair, urine, nails and blood for quantifying methylation levels at 10 metastable epialleles. Additional data collected include demographic information, zygosity, chorionicity and questionnaire based measures of infant behaviors. Recruitment for all three studies was completed in early 2020. EpiTwin recruited 80 twin pairs (50% monochorionic), 31 twin pairs completed the BOPP protocol, and 68 singleton infants participated in BIO. The psychometric properties of the data from all three studies are being analyzed currently. The resulting findings will inform the development of the full BITS protocol, with the goal of completing assessments at 4-, 6-. 12- and 14- months of age for 400 twin pairs.