IRS1 and type 2 diabetes mellitus: In generalised linear regression analyses adjusted for age, sex and type 2 diabetes (Table 3), the IRS1 allele A (972Arg) was associated with none of the marker of glycaemia, insulin resistance or insulin sensitivity, both overall and in participants with and without type 2 diabetes taken separately; with no evidence of significant statistical interaction by type 2 diabetes status (all interaction p ≥ 0.330), except for 2 hour glucose where the effect size appeared to be greater although non-significantly among diabetic than non-diabetic participants (interaction p = 0.038).