Cumulative incidence of natural menopause and surgical menopause by DCCT/EDIC treatment group. At time zero (DCCT baseline), the mean age of the female cohort was 26 years (range 13–39). After an average of 25 years of DCCT/EDIC follow-up, 240 women had reached natural menopause (2% during the DCCT and 98% during EDIC) and 115 women underwent surgical menopause (20% during the DCCT and 80% during EDIC). The mean ages at natural menopause and surgical menopause were 49.6 ± 4.4 and 41.4 ± 6.7 years, respectively.