C3 and polycystic ovary syndrome: In view of the apparent correlations of the proteins with insulin resistance and BMI, seen in Figure 2 and Figure 3, a multivariable regression model was undertaken, adjusting the protein results for BMI and insulin levels to determine if the adjusted PCOS versus the control differed: C3b, iC3b, C3d, factor I, CFHR5, factor B, factor H and C5a all remained significantly different (p < 0.05) after accounting for BMI and HOMA.