Agents useful for the treatment of various metabolic disorders, such as insulin resistance syndrome, diabetes, polycystic ovary syndrome, hyperlipidemia, fatty liver disease, cachexia, obesity, atherosclerosis and arteriosclerosis are disclosed, compound of the formula (I): wherein n is 1 or 2; m is 0, 1, 2, 3, 4, 5, 6, 7 or 8; q is 0 or 1; t is 0 or 1; R1 is alkyl having from 1 to 3 carbon atoms; R2 is hydrogen, halo, alkyl having from 1 to 3 carbon atoms, or alkoxy having from 1 to 3 carbon atoms; R3 and R4 together are alkyl having two or three carbon atoms; or R3 and R4 are the same as each other and each is methyl or ethyl; R5 is hydrogen or alkyl having from one to six carbon atoms. A is phenyl, unsubstituted or substituted by 1 or 2 groups selected from: halo, hydroxy, alkyl having 1 or 2 carbon atoms, perfluoromethyl, alkoxy having 1 or 2 carbon atoms, and perfluoromethoxy; or A is cycloalkyl having from 3 to 6 ring carbon atoms wherein the cycloalkyl is unsubstituted or one or two ring carbons are independently mono-substituted by methyl or ethyl; or A is a 5 or 6 membered heteroaromatic ring having 1 or 2 ring heteroatoms selected from N, S and O and the heteroaromatic ring is covalently bound to the remainder of the compound of formula (I) by a ring carbon. Alternatively, the agent can be a pharmaceutically acceptable salt of the compound of Formula (I).