MTNR1B and type 2 diabetes mellitus: In the UK Biobank, MTNR1B variants were not associated with cardiometabolic phenotypes, including type 2 diabetes prevalence, except that carriers of missense MTNR1B variants causing impaired MT2 signalling exhibited higher HbA1c levels compared with non-carriers (effect size, β, 0.087 SD [95% CI 0.039, 0.135]).