Given that CK has been associated with obesity and insulin resistance (19, 39, 40), both features of the metabolic syndrome, then it is not surprising that the association was found in this group of subjects; however, the PCOS subjects here were even more insulin resistant with a higher BMI and waist circumference and it may have been expected that the CK would have been higher than controls, though this was not found. This evidence concerns the gene INS and obesity due to melanocortin 4 receptor deficiency.