For example, the genotyping of clock genes in 346 Greek pregnant women and their risk of diabetes was performed, detecting that the polymorphisms of Bmal1 rs7950226 and rs11022775 are associated with gestational diabetes mellitus (P = 0.025, OR = 1.46 and P = 4.455e − 06, OR = 2.64, resp). This evidence concerns the gene CLOCK and diabetes mellitus.