INS and type 2 diabetes mellitus: Among study participants who remained non-diabetic (non-T2D cases), higher LPC(15:1), LPC(17:0), LPC(20:1), PC(22:6/18:2) and PC(15:1/18:2) were directly associated with better insulin sensitivity (Matsuda ISI) during the follow-up (β = 0.21 to 0.32, P = 0.039 to 0.001; Table 2), whereas higher isoleucine, phenylalanine and tyrosine were associated with lower Matsuda ISI (β = −0.23 to −0.36, P = 0.020 to 0.0003; Table 3).