COL1A1 and polycystic ovary syndrome: This relationship between C-peptide and PCOS further supports the fact that metabolic dysregulation and IR were positively correlated with the expression of genes KLF10 and TTN, and negatively correlated with genes COL1A1 and NBPF20. These findings suggest a connection between muscle metabolism and PCOS, as altered gene expression was associated with increased C-peptide levels and altered adipocyte size [24].