ETHANOL INGESTION AND THE DEVELOPMENT OF POST-EXERCISE KETOSIS IN NON-ALCOHOLIC HUMAN SUBJECTS

¹ Sport Science Centre, University of Cape Town Medical School, Observatory 7925
² Department of Medical Physiology and Biochemistry, University of Stellenbosch, Tygerberg 7505, South Africa

Alcoholic ketosis occurs in alcoholics, who have been shown also to be more predisposed than normal to post-exercise ketosis (Chalmers, Sulaiman & Johnson, 1977). We therefore studied post-exercise ketosis in ten normal people who drank 1·6 mol ethanol at 18.00-21.00 h, and then did a 12 km walk at 07.00 h the next morning. (The timing of the alcohol ingestion was prompted by the finding that alcoholic ketosis usually develops after the blood ethanol concentrations have fallen to zero.) Ten subjects who had not drunk alcohol for 60 h, acted as controls. All subjects were observed till 16.00 h. The blood 3-hydroxybutyrate level rose from 0·034 ± 0·006 to 0·336 ± 0·073 mmol/l (P 0·001) during the 9 h observation period in the controls, and from 0·038 ± 0·009 to 0·352 ± 0·127 mmol/l (P 0·001) in the test subjects. The differences between the two groups are not significant. Plasma free fatty acid concentrations, and insulin/glucagon ratios of the two exercise groups did not differ signficantly from each other, or from those of a sedentary group (n = 16). Acute ethanol ingestion (1·6 mol/person) therefore does not predispose normal, non-alcoholic subjects to ketosis, even when ketogenesis is further stimulated by exercise.