INS and hyperinsulinism: Without infusing a large amount of exogenous insulin to establish hyperinsulinemia, different extents of C-peptide reduction, such as >30% (Heinemann et al., 2000), 35% (Starke et al., 1989), approximately 40% (Sorensen et al., 2010), >50% (Heinemann et al., 1999; Scholtz et al., 2005) were reported.