INS and diabetes mellitus: In lipidomic studies of pre-diabetes, ceramides of C16:0, C18:0, C20:0, and C24:0 carbon chain lengths were positively associated with fasting insulin glucose levels and IFG while the association was reversed for sphingomyelins of C16:0, C18:0, 20:0, and C24:0 carbon chain length11,36, although the latter seemed to be driven by differences in BMI among the cohort.