ANGPTL8 and metabolic syndrome: During the stable clamping state, circulating ANGPTL8 was maintained at a lower level in all three groups due to hyperinsulinaemia (from 0.38 ± 0.17 to 0.15 ± 0.09 μg/L for the controls, from 0.49 ± 0.15 to 0.20 ± 0.08 μg/L for non-MetS, and from 0.68 ± 0.14 to 0.20 ± 0.08 μg/L for MetS).