Epidemiology of menarche and menstrual disturbances in an unselected group of women with insulin-dependent diabetes mellitus compared to controls.

To describe the age at menarche and the prevalence of menstrual disturbances in an unselected group of women with insulin-dependent diabetes mellitus compared to controls, we identified all women having debut of diabetes mellitus before the age of 30 yr and living in the County of Funen, Denmark on July 1, 1987 and being between 18 and 49 yr old. The women received a structured questionnaire inquiring information concerning menstrual conditions. An age comparable group of nondiabetic women was used as controls; 245 (94%) diabetic women and 253 (88%) controls answered the questionnaire. Among women with debut of diabetes before the age of 10 yr, the age at menarche was delayed 1 yr when comparing to controls (P less than 0.0001). During the past 6 months before answering the questionnaire, 8.2% of the diabetic women and 2.8% of the controls had experienced episodes of secondary amenorrhea (P less than 0.01). Corresponding figures for oligomenorrhea were 10.6% and 4.8% (P less than 0.02), for polymenorrhea 7.3% and 5.2% (NS), and for all types of menstrual disturbances 21.6% and 10.8%, respectively (P less than 0.005). Episodes of secondary amenorrhea occurring more than 6 months before answering the questionnaire had been experienced by 10.7% of the diabetic population vs. 4.8% of the controls (P less than 0.05); corresponding figures for primary amenorrhea were 4.9% and 1.2%, respectively (P less than 0.05). We conclude that the age at menarche among women having developed insulin-dependent diabetes mellitus before the age of 10 yr was delayed by 1 yr when compared to controls. The overall prevalence of menstrual disturbances is increased in diabetic women compared to nondiabetic controls.