COT-6 Body mass index and height in relation to brain tumor risk in a Japanese population

Purpose: Because the prognosis of the malignant brain tumor including glioblastoma is extremely worse than other cancer, it is important to clarify the preventive factors of the brain tumor in the prospective cohort study. In the Japanese epidemiologic study of the brain tumor, the report of the prospective cohort study has not been accomplished. Therefore, we have reported the study in recent years from a multipurpose cohort study (Japan Public Health Center-based Prospective Study: JPHC study) that the national cancer center was mainly conducted. This prospective study investigated the association between height and BMI (Body mass index) and brain tumor risk in an Asian population, whose distribution of anthropometric data differs from Westerners. Methods: A total of 106,324 subjects (50,438 men and 55,886 women) enrolled in JPHC Study, was followed from 1990. We divided participants into 5 categories based on the distribution of BMI as <18.5, 18.5- <23, 23- <25, 25- <27.5, and >-27.5 Kg/m2. We used the Cox proportional hazards regression model and estimated brain tumor incidence by gender and tumor subtype, with adjustment for potential confounding variables; age, sex, pack-years of cigarette smoking, alcohol intake, coffee intake, green tea intake, past history of allergy and past history of diabetes mellitus.Results: During an average follow-up of 18.1 years, 157 incident cases of brain tumor were newly identified, included glioma (n=60), meningioma (n =51), lymphoma(n=9), schwannoma(n=3), pituitary adenoma(n=2), and others(n=32). Higher BMI was significantly positively associated with the risk of brain tumor. This positive association of BMI was stronger in men and for meningioma in subgroup analyses. In contrast, height showed no clear association with brain tumor risk. Conclusion: Higher BMI was associated with an increased risk of brain tumor, in particular of meningioma, and among men.Full article has been published annals of epidemiology.