A method of activating PPAR receptors in a subject, said method comprising administering to said subject an effective PPAR receptor activating amount of a pyrrolopyridine compound corresponding to formula (I): ##STR00001## wherein R, R.sub.1, R.sub.2, R.sub.3, R.sub.4, X, Ar and n have defined meanings, or a pharmaceutically acceptable salt thereof, particularly as part of the treatment of a disorder or disease state selected from the group consisting of atherosclerosis, myocardial infarction, hypertension, and cerebral vascular disease.