The Rotterdam study investigated SIRT1 variation (assessed by three tagging SIRT1 SNPs: rs7895833, rs1467568 and rs497849) in relation to BMI and risk of obesity in 4 573 participants, including 413 individuals with prevalent and 378 with incident type 2 diabetes mellitus (T2DM).20 In homozygous carriers with prevalent T2DM, the SIRT1 haplotype 1 had 1.9 times (95% CI: 1.1–3.2) increased risk of CVD mortality compared to non-carriers. Here, SIRT1 is linked to obesity due to melanocortin 4 receptor deficiency.