In the meta-analysis published by Escobar-Morreale et al., the degree of elevation in circulating levels of CRP and IL-6 in PCOS was much higher when obesity was also present [39], and some studies showed that serum CRP elevations in women with PCOS were no longer statistically significant when controlling for body mass index [40], or that obesity alone is responsible for the systemic low-grade inflammation [41]. Here, IL6 is linked to obesity due to melanocortin 4 receptor deficiency.