Oxidative stress in diabetic macrovascular disease: does homocysteine play a role?
BACKGROUND
Non-insulin-dependent diabetes mellitus (NIDDM) and hyperhomocysteinemia are both associated with increased lipid peroxidation (oxidative stress). This may contribute to the accelerated vascular disease associated with these conditions. It is not known whether the coexistence of elevated homocysteine levels will stimulate oxidative stress further than that caused by diabetes alone.


METHODS
Plasma concentrations of thiobarbituric acid reactive substances (TBARS), an index of lipid peroxidation, were measured in patients with NIDDM who had previously had a methionine load test; some of the patients had hyperhomocysteinemia.


RESULTS
Plasma TBARS concentrations were elevated in diabetics with vascular disease. The additional presence of hyperhomocysteinemia was not associated with a further increase in plasma TBARS concentrations.


CONCLUSIONS
Lipid peroxidation is increased in patients with diabetes mellitus and macrovascular disease and is not further elevated by the coexistence of elevated homocysteine levels. It is possible that diabetes maximally stimulates oxidative stress and any further acceleration of vascular disease in patients who have coexistent hyperhomocysteinemia is mediated through mechanisms other than lipid peroxidation.
Fonseca
V A
VA
Division of Endocrinology and Metabolism, John L. McClellan Memorial Veterans' Hospital, Little Rock, AR 72205, USA.
Stone
A
A
Munshi
M
M
Baliga
B S
BS
Aljada
A
A
Thusu
K
K
Fink
L
L
Dandona
P
P
D000328:Adult; D000704:Analysis of Variance; D002545:Brain Ischemia / Q000097:blood / Q000209:etiology; D002340:Carotid Artery Diseases / Q000097:blood / Q000209:etiology; D016022:Case-Control Studies; D003327:Coronary Disease / Q000097:blood / Q000209:etiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D003925:Diabetic Angiopathies / Q000097:blood / Q000209:etiology*; D005609:Free Radicals / Q000097:blood; D006710:Homocysteine / Q000097:blood / Q000502:physiology*; D006801:Humans; D007004:Hypoglycemic Agents / Q000627:therapeutic use; D007328:Insulin / Q000627:therapeutic use; D015227:Lipid Peroxidation; D008297:Male; D008715:Methionine; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology*; D016491:Peripheral Vascular Diseases / Q000097:blood / Q000209:etiology; D013453:Sulfonylurea Compounds / Q000627:therapeutic use; D013858:Thiobarbiturates / Q000097:blood
D005609:Free Radicals; D007004:Hypoglycemic Agents; D007328:Insulin; D013453:Sulfonylurea Compounds; D013858:Thiobarbiturates; D006710:Homocysteine; D008715:Methionine; C029684:thiobarbituric acid