INS and type 2 diabetes mellitus: In 2086 participants without T2D, higher levels of plasma Cer (d18:1/16:0), Cer (d18:1/18:0), Cer (d18:1/20:0) or Cer (d18:1/22:0) were associated with higher plasma insulin and higher HOMA-IR levels at baseline and at follow-up an average of 5.4 years later.