Only two studies have examined the relationship between the degree of insulin resistance and CFR in patients without diabetes, with one study showing an inverse relationship between CFR and HOMA index in 45 women with suspected coronary artery disease and angiographically normal coronary arteries [20] and another showing correlation between CFR and insulin sensitivity measured using a hyperinsulinaemic euglycemic clamp in obese patients [21]. Here, INS is linked to Insulin resistance.