SUSCEPTIBILITY OF LDL TO OXIDATION IS NOT ASSOCIATED WITH THE PRESENCE OF CORONARY HEART-DISEASE OR RENAL DYSFUNCTION IN NIDDM PATIENTS

Coronary heart disease (CHD) is the leading cause of death among patie nts with non-insulin-dependent diabetes mellitus (NIDDM) and the oxida tion of low-density lipoprotein (LDL) may be an essential factor in th e development of atherosclerotic lesions. Therefore, we studied the in vitro susceptibility of LDL to copper-induced oxidation in 72 NIDDM p atients and 94 well-matched non-diabetic control subjects. There was n o significant difference in the lagtime of LDL oxidation between NIDDM patients and control subjects (68.1 +/- 8.8 vs. 66.7 +/- 9.2 min, res pectively, P = 0.29). The plasma alpha-tocopherol/LDL-ratio was the mo st significant determinant of the lagtime in multiple regression analy sis. High level of serum triglycerides was associated with decreased l agtime in control subjects, but not in NIDDM patients. Blood glucose b alance was not associated with LDL susceptibility to oxidation in NIDD M patients. Subjects with CHD did not have LDL susceptibility to oxida tion different from that of subjects without CHD in either of the stud y groups. Urinary albumin excretion or glomerular filtration rate was not associated with the lagtime of LDL oxidation in NIDDM patients. In conclusion, these data suggest that diabetes and hyperglycemia per se do not affect the susceptibility of LDL to oxidation. The presence of CHD or renal dysfunction were not associated with LDL susceptibility to oxidation. (C) 1998 Elsevier Science B.V. All rights reserved.