A Within-Sibling Pair Analysis of Lifestyle Behaviors and BMI Z-Score in the Multi-center I.Family Cohort Study

Leonie Helen Bogl, Kirsten Mehlig, Guiomar Masip, Nathalie Michels, Lucia A. Reisch, Valeria Pala, Angie S. Page, Dénes Molnar, Michael Tornaritis, Toomas Veidebaum, Luis Alberto Moreno, Wolfgang Ahrens, Lauren Lissner, Antje Hebestreit, Jaakko Kaprio, Anna Keski-Rahkonen, Timm Intemann, Paola Russo, Laura Johnson

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Objectives: The aim was to investigate associations betweenlifestyle behaviors and BMI z-scores after controlling for potential familialconfounding by comparing sibling pairs.

Methods: Within the European I.Family cohort, weconducted a cross-sectional analysis of 2 subsets of children: 1) among allsame-sex sibling pairs with a maximal age difference of four years (n=1404,mean age 10.7 years) and 2) among overweight-discordant sibling pairs (definedas one overweight or obese sibling with a non-overweight sibling and a BMIdifference of at least 10 percentiles) (n=304, mean age 11.3 years). Physicalactivity was measured by accelerometry and dietary intake by 24-hour dietaryrecalls. Sedentary behaviors and potential covariates were assessed byquestionnaires filled in by the children or their parents. Mixed linearregression was used to examine the associations between sibling differences (?)in lifestyle behaviors and ?BMI z-scores adjusting for ?height, ?age and sex,and the correlations between children within families and countries.

Results: Among all sibling pairs, the siblings withhigher screen time, lower MVPA, less sleep and higher intake of energy andunhealthy foods showed higher BMI z-scores. Within the overweight-discordantpairs, ?screen time and ?MVPA were significantly related to ?BMI z-scores. Ofthe overweight siblings, 37% were on a weight-loss diet, while thecorresponding number in non-overweight siblings was only 12%.

Conclusion: Lifestyle behaviors explain part of BMI z-scoredifferences among siblings raised in the same household. It remains to beexplored whether genetic variants distinguish overweight-discordant siblingsand whether these genes influence food intake or energy expenditure behaviors.This work was done as part of the I.Family Study (http://www.ifamilystudy.eu/).We gratefully acknowledge the financial support of the European Communitywithin the Seventh RTD Framework Programme Contract No. 266044.

Original languageEnglish
Title of host publicationAbstract book for the ISBNPA 2018 Annual Meeting in Hong Kong
Number of pages1
Publisher International Society of Behavioral Nutrition and Physical Activity
Publication date2018
Article numberO.42.4
ISBN (Print)9781732401105
Publication statusPublished - 2018
EventISBNPA 2018 Annual Meeting: Advancing Behaviour Change Science - Hong Kong, China
Duration: 3 Jun 20186 Jun 2018
Conference number: 17


ConferenceISBNPA 2018 Annual Meeting
CityHong Kong
Internet address

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