INS and type 2 diabetes mellitus: The NEFA concentration is negatively regulated by the circulating insulin concentration in normal subjects (Campbell, Carlson, Hill, & Nurjhan, 1992; Nurjhan, Campbell, Kennedy, Miles, & Gerich, 1986), in those with T2DM (Howard et al., 1979) and in those with T1DM as well (Jensen et al., 1989).