Marked secular trends in obesity prevalence are apparent throughout childhood, and this is leading to more adolescent girls presenting with clinical features of PCOS, including acne, hirsutism and menstrual irregularity. These girls typically also have central obesity and relatively early menarche (onset of first menstrual period).
Certain overweight and obese girls may be particularly prone to developing PCOS features. Several studies have identified a risk pathway of low birth weight, postnatal catch-up growth, central obesity, insulin resistance and hyperandrogenaemia, which may be present even before puberty. These girls have a relatively early puberty onset, rapid progression through puberty, and consequently earlier menarche. Their puberty is accompanied by a marked amplification in metabolic and body composition abnormalities, and by the development of dyslipidaemia and ovarian hyperandrogenism. The clinical manifestation of PCOS features in such girls may therefore represent not the end-point of the pathway, but simply a staging post on the road to future T2DM and CVD.
Identification of such developmental factors to adolescent PCOS has allowed intervention studies using insulin sensitisation early on in the pathway. Short-term studies have shown improvements in metabolic traits, while long-term trials confirm the beneficial effects on body composition, and also demonstrate remarkable benefits on slowing pubertal progression and prolonging the pubertal growth period leading to taller adult height. Future studies need to address whether similar benefits might be achieved through other strategies to reduce insulin resistance during this crucial period, and to confirm the potential long-term reductions in T2DM and CVD risks.
In conclusion, PCOS is an increasing co-morbidity of overweight and obesity in adolescent girls. Importantly, PCOS appears to identify a group of children with particular increased susceptibility to future metabolic disease. Treatment aims should therefore consider not only the short-term alleviation of presenting symptoms, but should also address their longer-term metabolic health.