Substituted heterocyclic derivatives are provided which have the structure ##STR00001## wherein Z.sup.1 is (CH.sub.2).sub.q or C.dbd.O; Z.sup.2 is (CH.sub.2).sub.p or C.dbd.O; D is --CH.dbd. or C.dbd.O or (CH.sub.2).sub.m where m is 0, 1, 2 or 3; n=0, 1 or 2; p=1 or 2; q=0, 1 or 2; Q is C or N; X is CH or N; X.sub.2 is C, N, O or S; X.sub.3 is C, N, O or S; X.sub.4 is C, N, O or S; X.sub.5 is C, N, O or S; X.sub.6 is C, N, O or S; provided that at least one of X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 is N; and at least one of X.sub.2, X.sub.3, X.sub.4, X.sub.5 and X.sub.6 is C; A, B, R.sup.1, R.sup.2, R.sup.2a, R.sup.2b, R.sup.4, R.sup.3, E, Z and Y are as defined herein. In addition, a method is provided for treating diabetes, Type 2 diabetes, insulin resistance, hyperglycemia, hyperinsulinemia, elevated blood levels of fatty acids or glycerol, hyperlipidemia, obesity, hypertriglyceridemia, Syndrome X, or atherosclerosis, wherein the substituted heterocyclic derivatives are administered in a therapeutically effective amount to a patient.