Obesity-related genetic variants, including TMEM18 (rs6548238), SH2B1 (rs7498665), and GNPDA2 (rs10938397), have been shown to be associated with obesity in the general population.
In the meta-analysis of 42 studies for 11 obesity/BMI-associated loci, we observed a statistically significant association of the FTO rs9939609 polymorphism (66 425 T2D cases/239 689 normoglycaemic subjects; P = 1·00 × 10(-41) ) and six other variants with T2D risk (17 915 T2D cases/27 531 normoglycaemic individuals: n = 40 629-130 001; all P < 0·001 for SH2B1 rs7498665, FAIM2 rs7138803, TMEM18 rs7561317, GNPDA2 rs10938397, BDNF rs925946 and NEGR1 rs2568958).
The associations of rs925946 and rs7498665</span> obesityrisk va</span>riants with increased BMI (β = 0.180 [0.022-0.339], P value = 0.0258 and β = 0.166 [0.019-0.313], P value = 0.0271, respectively) were slightly attenuated after adjusting for snacking (β = 0.151 [-0.006 to 0.309], P value = 0.0591 and β = 0.152 [0.006-0.297], P value = 0.0413).
Carriers of obesity risk alleles of non-synonymous SNPs in SH2B1 (rs7498665, Thr484Ala) or APOB48R (rs180743, Pro419Ala), as genotyped by TaqMan, were analysed for changes in anthropometrics (body-mass index (BMI), and standardized BMI (BMI-SDS)), blood pressure (systolic and diastolic) and plasma parameters (total cholesterol, LDL-cholesterol, HDL-cholesterol, triacylglycerides, glucose, insulin, and HOMA).We observed no evidence for an association of the obesity risk alleles to alterations in any of the analyzed phenotypes.
For the non-synonymous SNP rs7498665(Thr484Ala) we observed nominal over-transmission of the previously described risk allele in 705 obesity trios (nominal p = 0.009, OR = 1.23) and an increased frequency of the same allele in 359 cases compared to 429 controls (nominal p = 0.042, OR = 1.23).
Six other SNPs, rs2815752 (NEGR1), rs10938397 (GNPDA2), rs10838738 (MTCH2), rs7498665 (SH2B1), rs17782313 (MC4R) and rs11084753 (KCTD15), were not associated with obesity (P>0.05).