Endocrine Abstracts

Aim: To investigate reproductive function disorders in young women with type 1 diabetes mellitus (T1DM).

Patients and methods: We studied 53 women with T1DM (duration 8.0±5.6 y) and 51 healthy controls with normal menstrual cycles and no clinical hyperandrogenism, matched for age (19.4±4.3 vs 20.8±3.1 years, P=0.063) and body mass index (BMI) (22.2±2.7 vs 21.4±1.9 kg/m², P=0.088). T1DM (insulin regimen, glycemic control, hypoglycemic episodes, diabetic complications) and reproductive (age at menarche, duration of menstrual cycle and menses, pregnancies and signs of hyperandrogenism) parameters were recorded. Morning blood samples were obtained for biochemical and hormonal assessments at the first phase of menstrual cycle.

Results: T1DM diagnosis was made at the age of 11.5±4.7 years; in 17% of patients (9/53) ketoacidosis was the presenting symptom. Patients were treated with multiple daily injections (83%, 44/53) or insulin pump therapy (17%, 9/53), with total insulin requirements of 0.7±0.22 iu/kg. Current glycosylated haemoglobin (HbA1c) was 8.4±1.8%, with 7.3±7.9 hypoglycemic episodes per month. Complications consisted of diabetic retinopathy (1.9%, 1/53) and albuminuria (5.7%, 3/53). There was no difference in birth weight (3214±629 g vs 3145±496 g, P=0.601). Two patients (3.8%) had not experienced menarche at the age of 15.5 and 16.6 y; for the rest, the age at menarche was delayed compared with controls (12.7±1.3 vs 12.0±1.0 years, P=0.03). Patients who had experienced menarche were studied 7.3±4.7 years after, with 23.5% (12/51) having oligomenorrhea. There was no difference in family history for menstrual disturbances (13.2%, 7/53 vs 15.7%, 8/51). The prevalence of hirsutism and acne was high in patients with T1DM (32.1%, 17/53 and 45.3%, 24/53, respectively). There were no differences in total testosterone (0.43±0.14 vs 0.39±0.14 ng/ml), DHEA-S (268.5±112 vs 237.5±106 μg/dl) or Δ₄-Androstenedionone (2.4±1.3 vs 1.9±0.5 ng/ml) concentrations between patients and controls (P>0.05). However, patients with T1DM had lower SHBG concentrations (61±17 vs 103±41 nmol/l, P=0.001) reminiscent of higher insulin concentrations in patients through the exogenous administration.

Conclusions: T1DM in young women is associated with delayed menarche, and increased prevalence of oligomenorrhea and clinical hyperandrogenism probably attributed to the higher free testosterone concentrations due to decreased SHBG levels. Physicians should be aware of these reproductive disorders when dealing with such women.