Background: The impact of adiposity in adolescence on death during adulthood is uncertain.
Objective: To examine the relation between adiposity in adolescence and premature death in women.
Design: Prospective cohort study.
Setting: United States.
Participants: 102,400 women from the Nurses' Health Study II who were 24 to 44 years of age and free of cancer at baseline. Ninety percent were of non-Hispanic white ethnicity.
Measurements: In 1989, current weight and height and recalled weight at age 18 years were assessed by using validated questionnaires, and body mass index (BMI) was calculated. Hazard ratios for death and 95% CIs were adjusted for potential confounders, including cigarette smoking, alcohol use, and physical activity during adolescence.
Results: During 12 years of follow-up, 710 participants died. Compared with a BMI of 18.5 to 21.9 kg/m2 at age 18 years, the hazard ratio for premature death was 0.98 (95% CI, 0.78 to 1.23) for a BMI less than 18.5 kg/m2, 1.18 (CI, 0.97 to 1.43) for a BMI of 22.0 to 24.9 kg/m2, 1.66 (CI, 1.31 to 2.10) for a BMI of 25.0 to 29.9 kg/m2, and 2.79 (CI, 2.04 to 3.81) for a BMI of 30 kg/m2 or greater. Among participants who never smoked, a BMI of 22.0 to 24.9 kg/m2 at age 18 years was also associated with increased premature death (hazard ratio, 1.50 [CI, 1.16 to 1.94]). Associations between BMI at age 18 years and death could only partly be explained by adult BMI measured in 1989.
Limitations: Because of the observational study design, residual confounding by imperfectly measured or unknown confounders may still be present.
Conclusion: Moderately higher adiposity at age 18 years is associated with increased premature death in younger and middle-aged U.S. women.