Prospective cohort study of body mass index in adolescence and death from stomach cancer in Japan.

We investigated the association between body mass index (BMI) values and the risk of death from stomach cancer later in life. From 1992 to 2000, 28 443 participants (13 211 men and 15 232 women) were followed, and 129 deaths from stomach cancer (86 men and 43 women) occurred. BMI (BMI at the baseline) and BMI(20y) (BMI at age 20 years) were obtained by questionnaire at the beginning of the study. Men in the middle and highest tertiles of BMI(20y) had a higher risk of death from stomach cancer than those in the lowest tertile (after controlling for covariates, hazard ratio [HR] = 2.73 with 95% confidence interval [CI] 1.26-5.89 for the middle tertile; HR = 2.15 with 95% CI 0.97-4.73 for the highest tertile), although there was no significant trend (P = 0.30). Likewise, women in the middle and highest tertiles of BMI(20y) had an increased risk of death from stomach cancer (HR = 5.17 with 95% CI 1.50-17.87 for the middle tertile; HR = 4.22 with 95% CI 1.18-15.05 for the highest tertile; P for trend = 0.05). The analysis of BMI at the baseline did not show a significant relationship with the risk of death from stomach cancer. These results suggest that a high BMI(20y) is associated with an increased risk of death from stomach cancer.