Enzyme activity of P450c21 lessened in lean patients with PCOS
The activity level of P450c21, an adrenal-specific enzyme, is reduced in lean patients with polycystic ovary syndrome (PCOS), suggesting a role of adrenal androgen excess in obesity, a recent study has found.
The study included 1,044 women with PCOS, of which 350 were lean, 312 were overweight and 382 were obese. Patients who were pregnant, had other endocrine disorders, had a history of ovarian surgery, and took medications that may have affected adrenal or gonadal function were excluded.
Liquid chromatography-tandem mass spectrometry was used to compare the steroid hormones with 366 healthy controls (n=203 lean; n=32 overweight; n=131 obese).
In terms of hormone concentrations, lean PCOS patients showed significantly higher levels of dehydroepiandrosterone sulphate (DHEAS; p=0.015), progesterone (p<0.0001) and 17-hydroprogesterone (17-OHP; p<0.001), and significantly lower free androgen index (FAI; p<0.001).
Additionally, enzyme activity of P450c16 (p<0.001), P450aro (p<0.001) and 3βHSD2 (p<0.001) were significantly higher in lean compared with obese PCOS patients. In contrast, enzyme activities of P450c17 (p<0.001) and P450c21 (p=0.001) were significantly decreased in obese PCOS patients.
Body mass index was significantly negatively correlated with the enzyme activities of P450c17 (p=0.004), P450aro (p<0.001) and 3βHSD2 (p<0.001), and significantly positively associated with the activity of P450c21 (p<0.001).
The current findings suggest that “that the adrenal androgen excess played different roles in lean and obese PCOS patients, which represented as different enzyme activity in the steroidogenic pathway,” researchers said.