The increase of leukocytes as a new putative marker of low-grade chronic inflammation and early cardiovascular risk in polycystic ovary syndrome

White blood cell (WBC) count is a known risk factor for atherosclerotic vascular disease in adult women. Polycystic ovary syndrome (PCOS) is potentially a risk factor for atherosclerosis and cardiovascular disease. The aim of the present study was to investigate leukocyte count in PCOS. One hundred and fifty PCOS women matched for age and body mass index with 150 healthy women were enrolled. WBC count, C-reactive protein, and a complete anthropometrical, metabolic, and hormonal evaluation were performed in both groups. Serum insulin, glucose level, and lipid profile were also measured in each subject. WBC count was significantly higher (P <0.0001) in PCOS with (interquartile range in parentheses) 7260 (393) cells/mm³, compared with controls with 5220 (210) cells/mm³. C-reactive protein levels were significantly increased (P <0.0001) in PCOS with 2 (1) mg/liter compared with healthy women with 0.7 (0.8) mg/liter. In both groups, there was a significant (P <0.0001) linear correlation between WBC count and homeostasis model assessment score (PCOS, r = 0.94; controls, r = 0.91). Multiple linear regression analysis showed that other hormone levels are not predictors of leukocyte count both in PCOS and control women. In conclusion, our data demonstrate that PCOS women have an increased WBC count that correlates with homeostasis model assessment values.