Diagnosis accuracy of ALT and waist circumference as a screening test for insu- lin resistance

ALT and waist circumference are both correlated to insulin resistance (IR). Objective : To determine whether ALT provides information in addition to waist circumference for identifying IR. Methods : IR was defined by HOMA-IR index =3. In this Europid population, a waist circumference =80 cm in women and =94 cm in men was considered excessive. Elevated ALT was defined using either the usual cut-off or updated cut-offs of 19 U/l in women and 30 U/l in men. Results : 288 participants without medication affecting insulin concentration were included. 81 (28%) were insulin resistant, 30 (10%) and 98 (34%) had increased ALT using usual and updated cut-offs, respectively, and 218 (76%) had excessive waist circumference. Among subjects with normal waist circumference, IR was as frequent in participants with normal ALT as in those with increased ALT. Among subjects with excessive waist circumference, IR was less frequent in participants with normal ALT according to the usual cut-off (31% vs. 56%, p=0.01), and tended to be less frequent in participants with normal ALT according to updated cut-offs (29% vs. 41%, p=0.07) than in those with increased ALT. Conclusion : ALT is useful for identifying IR only if waist circumference is excessive. In subjects with excessive waist circumference, IR is present in more than 40% in women with ALT >19 U/l and in men with ALT >30 U/l, and in more than 50% in individuals with ALT >45 U/l. (Acta gastroenterol. belg., 2016, 79, 455-462).