title: Childhood body mass index growth trajectories and endometrial cancer risk.
abstract: Previously, we found that excess weight already in childhood has positive associations with endometrial cancer; however, associations with changes in body mass index (BMI) during childhood are not well understood. Therefore, we examined whether growth in childhood BMI is associated with endometrial cancer and its sub-types. A cohort of 155,505 girls from the Copenhagen School Health Records Register with measured weights and heights at the ages of 6-14 years and born 1930-1989 formed the analytical population. BMI was transformed to age-specific z scores. Using linear spline multilevel models, each girl's BMI growth trajectory was estimated as the deviance from the average trajectory for three different growth periods (6.25-7.99, 8.0-10.99, 11.0-14.0 years). Via a link to health registers, 1,020 endometrial cancer cases were identified, and Cox regressions were performed. A greater gain in BMI during childhood was positively associated with endometrial cancer but no differences between the different growth periods were detected in models adjusted for baseline BMI. The hazard ratios for the associations with overall growth during childhood per 0.1 z score increase were 1.15 (95% confidence interval [CI]: 1.07-1.24) for all endometrial cancers, 1.12 (95% CI: 1.04-1.21) for estrogen-dependent cancers, 1.16 (95% CI: 1.06-1.26) for endometrioid adenocarcinomas and 1.46 (95% CI: 1.16-1.84) for non-estrogen-dependent cancers. Growth in BMI in early life is positively linked to later endometrial cancer risk. We did not identify any sensitive childhood growth period, which suggests that excess gain in BMI during the entire childhood period should be avoided.
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, Denmark.
authors.forename: Julie
authors.initials: J
authors.lastname: Aarestrup
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, Denmark.
authors.forename: Michael
authors.initials: M
authors.lastname: Gamborg
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Tilling
authors.affiliation: Department of Gynecology and Obstetrics, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
authors.forename: Lian G
authors.initials: LG
authors.lastname: Ulrich
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, Denmark.|Novo Nordisk Foundation Center for Basic Metabolic Research, Section on Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Thorkild I A
authors.initials: TI
authors.lastname: Sørensen
authors.affiliation: Institute of Preventive Medicine, Bispebjerg and Frederiksberg Hospital, The Capital Region, Copenhagen, Denmark.|Novo Nordisk Foundation Center for Basic Metabolic Research, Section on Metabolic Genetics, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jennifer L
authors.identifier: http://orcid.org/0000-0002-9649-6615
authors.initials: JL
authors.lastname: Baker
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D003718:Denmark; D016889:Endometrial Neoplasms / Q000209:etiology* / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism; D005260:Female; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D015430:Weight Gain; D055815:Young Adult
chemical_list: D004967:Estrogens
keywords: body weights and measures; child; endometrial neoplasms; growth and development; obesity