Association does not mean causality, but two recently-published studies using a Mendelian randomisation approach provided strong evidence that circulating SHBG is involved directly in the pathogenesis of type 2 diabetes in both men and women.24,25 These studies described the effect of genotypes of gene-encoding SHBG on plasma levels of SBHG and the risk of development of type 2 diabetes. Here, SHBG is linked to type 2 diabetes mellitus.