Mean ( 95 % CI ) GGT decreased in subjects who reverted to normal glucose tolerance ( NGT ) , whereas it increased in subjects who deteriorated to diabetes ( NGT : -3.5 ( -6.4 to -0.6 ) ; IGT :0.3 ( -3.0 to 2.4 ) ; DM :8.3 ( 3.6 to 13.0 ) UL ( -1 ) ; P < 0.0001 ) .