Highly significant, replicated studies, p=3.6e-12. Risk allele A appears to represent a greater risk in those with low BMI, which is plausible due to the known role of FTO in obesity. This SNP is in intron 8, whereas BMI SNP's are usually in intron 1. The association was much stronger for those in the lowest quartile of BMI (1.66 per A allele risk) vs those in the other 3 quartiles (1.03 per A allele risk - no longer statistically significant).
Risk for those in higher 3 quartiles of BMI is likely not substantially affected.