Association between red blood cell distribution width and polycystic ovary syndrome

The red blood cell distribution width (RDW) is being recognized as a marker of chronic inflammation and routinely reported as part of a complete blood count (CBC) without any additional costs. High levels of RDW associate with oxidative stress and cardiovascular disease risk. We aimed to investigate the relation between the level of RDW and high-sensitive C-reactive protein (hs-CRP), HOMA-IR, BMI and body fat percentage in women with polycystic ovary syndrome (PCOS).

Cross-sectional and observational studies were conducted in 90 subjects with PCOS and 87 age- and BMI-matched controls. Body fat percentage, CBC, fasting serum glucose, serum insulin, hs-CRP, lipids, and total and free-testosterone levels were measured.

RDW levels were significantly higher in the PCOS group compared with the control group (12.98 ± 0.92% versus 12.59 ± 0.84%, p = 0.004). RDW levels were positively correlated with hs-CRP, HOMA-IR and BMI. Multivariate analysis showed that high-RDW levels were associated with PCOS. Subjects with the highest quartile RDW levels were nearly 2.8 times more likely to develop PCOS compared with subjects with the lowest quartile RDW. ROC curve analysis showed that RDW levels were useful as a diagnostic marker for PCOS. The optimal cut-off value for detecting PCOS was ≥12.54% (sensitivity 67% and specificity 70%).

RDW levels were higher in women with PCOS, and high-RDW levels were independently associated with PCOS. This link in between RDW and PCOS may be due to an underlying chronic inflammation in subjects with PCOS.