Nanri A, et al. - Using data from a large-scale population-based cohort study in Japan, researchers prospectively examined the relationship between menstrual and reproductive factors (eg, age at menarche, parity and breast-feeding) and type 2 diabetes risk. Study participants included 37,511 women (aged 45–75 years) who partook in the baseline (1990–1993), second (1995–1998), and third surveys (2000–2003) of the Japan Public Health Center-based Prospective Study, and who had no history of diabetes at the second survey. According to findings, higher parity might be correlated with an increased risk of type 2 diabetes among Japanese women, partly by increasing bodyweight. Other menstrual and reproductive factors, including age at menarche and menopause, reproductive life span, menopausal status, menstrual cycle, use of female hormones, age at first birth, and breast-feeding, were not appreciably related to type 2 diabetes risk.