Body size in different periods of life, diabetes mellitus, hypertension, and risk of postmenopausal endometrial cancer (Sweden)

Objective: To measure the association between endometrial cancer risk and obesity at age 18 and recently, adult weight gain, diabetes mellitus and hypertension.Methods: We performed a population-based, nationwide case–control study among postmenopausal women aged 50–74 years in Sweden, including 709 incident cases with histopathologically verified endometrial cancer and 3368 controls.Results: Compared to lean women (recent body mass index (BMI), i.e. kg/m² below 22.5), overweight women (recent BMI 28–29.99) had a 50% increase in risk for endometrial cancer (OR 1.5, 95% CI 1.0–2.1). Obese women (recent BMI 30–33.99) had a 3-fold increased risk (OR 2.9, 95% CI 2.0–4.0), and markedly obese women (recent BMI 34) a 6-fold increased risk (OR 6.3, 95% CI 4.2–9.5). The OR for Type 2 diabetes mellitus was 1.5 (95% CI 1.0–2.1) and for Type 1 diabetes mellitus it was 13.3 (3.1–56.4). The effect of recent BMI was similar for tumors having different degrees of differentiation and myometrial invasion, and did not vary with age, time since menopause, smoking status, diabetes mellitus, and use of contraceptives. Hypertension increased risk only among obese women. BMI at age 18, height, and adult weight change were not independent risk factors.Conclusions: Recent overweight/obesity and diabetes mellitus (Types 1 and 2) are associated with endometrial cancer risk. Hypertension increases risk among obese women.