Risk factors for meningioma in postmenopausal women: Results from the Iowa Women’s Health Study. Neuro Oncol

Few risk factors for meningioma, aside from increasing age and female sex, have been identified. We investigated risk factors for meningioma in elderly women, a group with a high incidence. We evaluated associations of demographic, lifestyle, medical history, and anthropo-metric variables with risk of meningioma in the Iowa Women’s Health Study (IWHS), a population-based, prospective cohort study. Risk factors were collected via questionnaires mailed in 1986 and 1992. Incident meningiomas were identified via linkages to Medicare. Cox regression models were used to examine the associ-ation of risk factors with meningioma incidence. The mean age at baseline of the 27,791 women in the analy-sis cohort was 69.3 years (range, 65.0–84.6 years). During 291,021 person-years of follow-up, 125 incident meningiomas were identified. After adjusting for age, lower levels of physical activity (relative risk [RR], 0.68 for high versus low; P for trend5.039), greater body mass index (BMI; RR, 2.14 for ≥35 versus 19.5– 24.9 kg/m2; P for trend 5.0019), greater height (RR, 2.04 for>66 versus ≤62 inches; P for trend 5 0.013), and a history of uterine fibroids (RR, 1.72; 95 % confi-dence interval, 1.19, 2.50) were positively associated with meningioma risk in multivariate analysis. BMI at age 18 and 30 years were not associated with risk. There were no associations with menstrual or reproduc-tive factors or other medical history and lifestyle factors. Physical activity, BMI, height, and history of uterine fibroids were associated with meningioma risk in older women. The positive association with height suggests a role for early life influences on risk, whereas the associ-ations with BMI and physical activity suggest a role for modifiable factors later in life