title: Body size in early life and adult levels of insulin-like growth factor 1 and insulin-like growth factor binding protein 3.
abstract: Body size in early life has been associated with breast cancer risk. This may be partly mediated through the insulin-like growth factor (IGF) pathway. The authors assessed whether birth weight, body fatness at ages 5 and 10 years, and body mass index (BMI; weight (kg)/height (m)(2)) at age 18 years were associated with plasma concentrations of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein 3 in 6,520 women aged 32-70 years at blood draw from the Nurses' Health Study (1990-2006) and Nurses' Health Study II (1997-2005). Birth weight, body fatness in childhood, and BMI at age 18 years were inversely associated with adult IGF-1 levels. For example, IGF-1 levels were 11.9% lower in women who reported being heaviest at age 10 years than in those who were leanest at age 10 (P-trend < 0.0001). Further, women who reported their birth weight as ≥10 pounds (≥4.5 kg) (vs. <5.5 pounds (<2.5 kg)) had 7.9% lower IGF-1 levels (P-trend = 0.002). Women whose BMI at age 18 years was ≥30 (vs. <20) had 14.1% lower IGF-1 levels (P-trend < 0.0001). Similar inverse associations were observed for insulin-like growth factor binding protein 3. These observations did not vary by adult BMI or menopausal status at blood draw. These findings suggest that altered IGF-1 levels in adulthood may be a mechanism through which early-life body size influences subsequent breast cancer risk.
authors.affiliation: Channing Laboratory, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, 181 Longwood Avenue, Boston, MA 02115, USA. liz.poole@channing.harvard.edu
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Poole
authors.forename: Shelley S
authors.initials: SS
authors.lastname: Tworoger
authors.forename: Susan E
authors.initials: SE
authors.lastname: Hankinson
authors.forename: Eva S
authors.initials: ES
authors.lastname: Schernhammer
authors.forename: Michael N
authors.initials: MN
authors.lastname: Pollak
authors.forename: Heather J
authors.initials: HJ
authors.lastname: Baer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood; D049628:Body Size / Q000502:physiology*; D001943:Breast Neoplasms / Q000097:blood / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I