Total and LDL combined vitamin E concentrations in plasma patient with non insulin dependent diabetes mellitus

ABSTRACT

Patients with diabetes mellitus are susceptible to oxidant-antioxidant imbalance. Diabetic complications such as nephropathy, neuropathy and retinopathy increase 'this susceptibility. Other traditional atherogenic risk factors such as hypertension, cigarette smoking and dyslipidemia can also induce oxidant stress. It is possible that the existence of two or more of the atherogenic risk factors may enhance oxidant-antioxidant imbalance. However, this proposal has not been fully studied. Aim: To determine plasma vitamin E concentrations, both total and the fraction within LDL particles in patients with sole noninsulin-dependent diabetes mellitus [N-1DDM] or N1DDM associated with one or more of the other risk factors of atherosclerosis. This study was conducted on 60 patients with NIDDM [32 males and 28 females]. They were classified into four groups [1] sole diabetic [n=20], [2] diabetic-hypertensive [n=10], [3] cigarette smoking diabetic [n=10] and [4] diabetic with multiple atherogenic risk factors [n=20]. Also, twenty clinically healthy individuals were investigated as a control group. Vitamin E was measured by high performance liquid chromatography [HPLC] while a plasma thiobarbituric acid reactive substance [malondialde-hyde] was determined colorimetrically. Plasma total vitamin E [VE] and vitamin E in LDL [VE-LDL] concentrations were significantly decreased while plasma malondialdehyde [MDA] levels were significantly increased in sole N1DDM, diabetic hypertensive, smoking diabetic and diabetic with multiple atherogenic risk factors groups in comparison to the corresponding values of the control group. These changes were noted more frequently and more severely in patients with multiple risk factors than those with single DM or DM with another risk factor. In these groups, vitamin E content in HDL showed significant negative correlation with LDL-C concentrations and significant positive correlation with HDL-C concentrations. Multiple regression analysis showed that vitamin E in HDL particles was an independent risk factor for coronary heart disease. The subnormal vitamin E content in LDL panicles may be a result of enhanced LDL oxidation in patients