The invention relates to the use of imidazole derivatives of the formula (1): ##STR00001## in which A, R'.sub.1, R'.sub.2 and R'.sub.3 are as defined in the description, as AMPK activators. The invention also relates to processes for the preparation of the said compounds, to their uses for the preparation of medicaments for the treatment of insulin resistance, diabetes and related pathologies, and also obesity, and to the pharmaceutical compositions comprising them. Certain compounds of the formula (1) are novel and, in this respect, also form part of the invention.