Menstrual irregularities are more common in adolescents with type 1 diabetes: association with poor glycaemic control and weight gain.

Ovarian function in post-menarchal girls with Type 1 diabetes was evaluated. Menstrual histories from 24 adolescents with Type 1 diabetes were compared with those from 24 age and sex matched controls. A fasting blood sample was obtained from subjects with Type 1 diabetes for the measurement of ovarian and adrenal sex hormones, LH and FSH, glucose and insulin, insulin-like growth factor-I (IGF-I), and insulin-like growth factor binding protein-1 (IGFBP-1); and an ovarian ultrasound scan was performed. Menstrual irregularity was more prevalent in patients with Type 1 diabetes than controls (54% vs 21%, p < 0.01) and their mean body mass index (BMI) was greater (22.3 +/- 0.5 (+/- SEM) vs 20.7 +/- 0.6 kg m-2, p < 0.05). Subjects with Type 1 diabetes with irregular menses (when compared with diabetic subjects with a regular cycle) had a significantly higher HbA1 (12.8 +/- 0.4 vs 10.5 +/- 0.5%, p < 0.01) and BMI (23.2 +/- 0.6 vs 21.4 +/- 0.6 kg m-2, p < 0.05) associated with a lower sex hormone binding globulin (SHBG) (37.2 +/- 4.0 vs 52.6 +/- 4.0 nmol l-1, p < 0.025) and IGF-I (1.4 +/- 0.2 vs 2.2 +/- 0.2 mUI-1, p < 0.025) and a higher LH:FSH ratio (2.6 +/- 0.5 vs 1.4 +/- 0.2, p < 0.05). Polycystic ovarian changes were identified in 10/13 (77%) of these patients with an irregular cycle. Menstrual irregularity is common in post-menarchal girls with Type 1 diabetes and is associated with poor glycaemic control and weight gain. The apparent high incidence of polycystic ovarian change requires further investigation.