Inclusion and exclusion criteria.
For both cohorts, patients with PCOS (aged 16-45 years) were recruited from a departmental database or from outpatients attending the University Hospital of Wales. A diagnosis of PCOS was made according to the Rotterdam criteria, with congenital adrenal hyperplasia, androgen-secreting tumours, Cushing’s syndrome, thyroid disease and hyperprolactinaemia excluded by biochemical testing. Subjects were also excluded if they were pregnant, breastfeeding or had a history of hypertension, hyperlipidaemia or diabetes, or current or previous (within 3 months) use of glucocorticoids, lipid-lowering agents, anti-hypertensives, anti-diabetics or anti-obesity drugs. Healthy volunteers were recruited by advertisement in the local press, and among students and staff within our Institution. Healthy volunteers had regular menstrual cycles (every 27–32 days) and their healthy state was established by history, physical examination and hormonal evaluation (thyroid function, prolactin, testosterone and 17-hydroxyprogesterone); those with features of hirsutism or a family history of PCOS were excluded. For cohort 1, in the PCOS group there were 15 current smokers and 12 ex-smokers (32.1%) compared with 11 current smokers and 19 ex-smokers among the healthy volunteers (31.6%). Nineteen subjects with PCOS (22.6%) were taking a combined oral contraceptive pill compared with 28 (29.5%) healthy volunteers. For cohort 2, in the PCOS group there were 2 current smokers and 1 ex-smoker (15%) compared with 1 current smoker and 2 ex-smokers among the healthy volunteers (15%). Of the PCOS group, 8 (40%) were taking a combined oral contraceptive pill compared with 7 (35%) healthy volunteers.