2.0.0.0 DI­AG­NOS­TIC TESTS FOR DI­A­BETES

2.1.0.0 In­tro­duc­tion

Di­a­betes may be di­ag­nosed based on plas­ma glu­cose cri­te­ria, ei­ther the fast­ing plas­ma glu­cose (FPG) value or the 2-h plas­ma glu­cose (2-h PG) value dur­ing a 75-g oral glu­cose tol­er­ance test (OGTT), or A1C cri­te­ria (6) (Table 2.2).

Gen­er­al­ly, FPG, 2-h PG dur­ing 75-g OGTT, and A1C are equal­ly ap­pro­pri­ate for di­ag­nos­tic test­ing. It should be noted that the tests do not nec­es­sar­i­ly de­tect di­a­betes in the same in­di­vid­u­als. The efficacy of in­ter­ven­tions for pri­ma­ry pre­ven­tion of type 2 di­a­betes (7,8) has pri­mar­i­ly been demon­strat­ed among in­di­vid­u­als who have im­paired glu­cose tol­er­ance (IGT) with or with­out el­e­vat­ed fast­ing glu­cose, not for in­di­vid­u­als with iso­lat­ed im­paired fast­ing glu­cose (IFG) or for those with predi­a­betes defined by A1C cri­te­ria.

The same tests may be used to screen for and di­ag­nose di­a­betes and to de­tect in­di­vid­u­als with predi­a­betes. Di­a­betes may be iden­tified any­where along the spec­trum of clin­i­cal sce­nar­ios: in seem­ing­ly low-‍risk in­di­vid­u­als who hap­pen to have glu­cose test­ing, in in­di­vid­u­als test­ed based on di­a­betes risk as­sess­ment, and in symp­tomat­ic pa­tients.