Metabolism of Free Fatty Acids During Exercise in Patients with Occlusive Arterial Disease of the Leg

Abstract

Several studies on turnover rate and oxidation of free fatty acids (FFA) have clearly shown that utilization of FFA accounts for a substantial fraction of the oxidative metabolism in exercising muscle (for a recent review see Carlson, Boberg and Hogberg, (2)). The fraction of FFA entering the muscle that is directly oxidized may be deteplined from the extraction of ¹⁴C-FFA together with the output of ¹⁴CO₂ and has been reported to be 75–100 per cent during exercise with the legs (10,11). For exercise with the forearm the corresponding range is 40–100 per cent; the fractional oxidation correlated negatively to the lactate/pyruvate ratio and positively to the oxygen consumption (5,6). The present study was undertaken in order to characterize the relationship between oxygen supply and oxidation of the FFA taken up by the exercising muscles. For this purpose patients with impaired blood flow capacity of the leg due to occlusive arterial disease were studied during bicycle exercise and compared with a group of healthy subjects.