Diabetes, Vol 48, Issue 9 1850-1855, Copyright © 1999 by American Diabetes Association
Hyperketonemia can increase lipid peroxidation and lower glutathione levels in human erythrocytes in vitro and in type 1 diabetic patients
SK Jain and R McVie
Department of Pediatrics, Louisiana State University Medical Center, Shreveport 71130, USA.
Recent studies have suggested that elevated cellular lipid peroxidation may
play a role in the development of cellular dysfunction and other
complications of diabetes. People with type 1 diabetes frequently encounter
elevated levels of the ketone bodies acetoacetate (AA),
beta-hydroxybutyrate (BHB), and acetone (ACE). This study was undertaken to
test the hypothesis that ketosis might increase lipid peroxidation and
lower glutathione (GSH) levels of red blood cells (RBCs) in diabetic
patients. This study demonstrates that incubation of AA with normal RBCs in
phosphate-buffered saline (37 degrees C for 24 h) resulted in marked GSH
depletion, oxidized glutathione accumulation, hydroxyl radical generation,
and increased membrane lipid peroxidation. Increases in oxygen radicals and
lipid peroxidation and depletion of GSH in RBCs were not observed with BHB
or ACE treatments. Similarly, there was a significant generation of
superoxide ion radicals even in a cell-free buffer solution of AA, but not
in that of BHB. The presence of BHB together with AA did not influence the
capacity of AA to generate oxygen radicals in a cell-free solution or the
increase in lipid peroxidation of RBCs incubated with AA. The antioxidants
vitamin E and N-acetylcysteine (NAC) blocked increase in lipid peroxidation
in AA-treated RBCs. To examine the effects of ketone bodies in vivo,
studies were performed that showed a significant decrease in GSH and an
increase in lipid peroxidation levels in RBCs of hyperketonemic diabetic
patients, but not in normoketonemic type 1 diabetic patients, when compared
with age-matched normal subjects. This study demonstrates that elevated
levels of the ketone body AA can increase lipid peroxidation and lower GSH
levels of RBCs in people with type 1 diabetes.