Long-Term Pharmacologic Doses of Vitamin E Only Moderately Affect the Erythrocytes of Patients with Type 1 Diabetes Mellitus

Abstract

In erythrocytes from diabetic patients, increased membrane lipid peroxidation might lead to abnormalities in composition and function. To study this relationship, we investigated the effects of a moderate pharmacologic dose of vitamin E for 1 y on erythrocyte membrane peroxidation in vitro and on its fatty acid composition, antioxidant capacity and rheological function. In a random and double-blind manner, type 1 diabetic patients (n ϭ 44) were assigned to the following two groups: Group S received 250 IU (168 mg) d-␣ tocopherol 3 times daily for 1 y. Group P received placebo for 6 mo followed by d-␣-tocopherol for an additional 6 mo. Variables were monitored every 3 mo. After 3 mo of supplementation, serum vitamin E doubled (P Ͻ 0.0005), thiobarbituric acid reactive substances in erythrocyte membranes incubated with tert-butyl hydroperoxide decreased by 25% (P ϭ 0.006) and the lagtime of fluorescence increased from 28 Ϯ 16 to 41 Ϯ 28 min (P ϭ 0.028). Patients who did not respond to supplementation (13 of 44) had lower serum lipids (P ϭ 0.017) and body mass index (P ϭ 0.024). We did not detect any significant effects of vitamin E supplementation on membrane lipid composition, antioxidant capacity or blood viscosity. Continuing supplementation for up to 1 y did not further affect serum vitamin E or membrane peroxidation. Stopping supplementation was followed by a return to inclusion values. These results show that the decrease in erythrocyte membrane peroxidation after vitamin E supplementation is moderate, saturable, reversible, restricted to some individuals and has no detectable effect on erythrocyte composition and function.

Oral antioxidant therapy improves endothelial function in Type 1 but not Type 2 diabetes mellitus

“…Vitamin E reaches its maximal antioxidant effect at 3 mo. The effect is maintained to 1 yr with continued therapy (38).…”

Effect of hydrosoluble vitamin E on erythrocyte membrane lipid composition in patients with advanced cirrhosis: An open‐label pilot trial

“…9 The prolonged administration of vitamin E in diabetics (who also suffer from erythrocyte membrane alterations) only moderately affected red blood cell membrane lipid peroxidation. 23 Overall, as the benefits of antioxidant to treat liver diseases in general remains unclear, 24 a significant improvement in the redox status and normalization of transaminases have been reported in 50 patients with cirrhosis after 6 months of 900 IU vitamin E daily. 14 Based on this, it can be speculated that the improvement in total and conjugated serum bilirubin in our patients treated with tocofersolan could be related to some mechanisms not strictly limited to erythrocyte membrane composition but to some general improvement in oxidative stress.…”

“…Second, tocofersolan improved vitamin E plasma levels and tended to improve erythrocyte membrane lipid abnormalities, but this may not be sufficient to correct severe oxidative stress that is reported in decompensated cirrhotics . The prolonged administration of vitamin E in diabetics (who also suffer from erythrocyte membrane alterations) only moderately affected red blood cell membrane lipid peroxidation . Overall, as the benefits of antioxidant to treat liver diseases in general remains unclear, a significant improvement in the redox status and normalization of transaminases have been reported in 50 patients with cirrhosis after 6 months of 900 IU vitamin E daily .…”

Blood viscosity, lipid profile and lipid peroxidation in type-1 diabetic patients with good and poor glycemic control: The promise and reality

“…[3] That is, individuals who are not at risk of lipid peroxidation vis-à-vis oxidative stress may not show remarkable response to antioxidant. Indeed, blood viscosity in diabetic type 1 children show a trend of increasing compared with apparently healthy individual; as well as positive relationship with blood pressure.…”