Effects of antioxidants on postprandial oxidative stress and endothelial dysfunction in subjects with impaired glucose tolerance and type 2 diabetes.

AIM: To compare changes in the oxidation-reduction balance and endothelial function before and after meal in patients with type 2 diabetes or impaired glucose tolerance and determine the effects of standard antioxidant supplementation. METHODS: Forty diabetics and 40 subjects with impaired glucose tolerance were compared with a control group. We assessed before and after a test meal (homogenized milkshake containing 80 g of saturated fat, amounting to 1,480 kcal), some reactive oxygen species, inflammation markers and flow-mediated vascular dilatation. These parameters were then reassessed after standard antioxidant treatment. RESULTS: After the meal, diabetics, subjects with impaired glucose tolerance and controls had higher levels of oxidant compounds compared to fasting levels. In subjects with diabetes and impaired glucose tolerance (IGT), Vascular Adhesion Molecule-1 and CRP were higher after the meal--diabetic subjects exhibited lower fasting flow-mediated dilatation, which deteriorated significantly after the meal. Antioxidant administration significantly improved the parameters investigated in all subjects. CONCLUSIONS: In diabetic subjects, altered glycaemia and lipaemia are closely correlated with markers of systemic oxidative stress. Our results show that the abnormal changes in oxidative-reductive balance parameters are paralleled by similar changes in markers of endothelial dysfunction and inflammation at 4 h after ingestion of a fatty meal. Supplementation with a pool of antioxidants can reduce oxidative stress and inflammation in healthy subjects and, more importantly, in IGT patients. This previous aspect suggests that the timing of antioxidant supplementation has an important role in endothelium protection in healthy and pre-diabetic subjects, and along with prompt antioxidant treatment before irreversible endothelial damage has occurred, may have an important protective role in subjects with IGT-patients who require administration of adequate dietary antioxidants.

Randomized clinical trial to compare the effects of methadone and buprenorphine on the immune system in drug abusers.

RATIONALE: Buprenorphine may be a useful alternative option to methadone in addicts. Opioids can produce severe changes in the immune system. OBJECTIVES: The objectives of this study are to compare the effect of sublingual buprenorphine and methadone on the immune system and to compare the two substances on the drying-out program compliance. METHODS: We studied 62 randomized outpatients for a period of 12 months. Subjects (55 males and 7 females; mean age 25+/-4 years; average history of heroin abuse being 2 years) on maintenance treatment were assigned in two groups (A and B). Methadone chloride (medium dose 100 mg/day) was administered to group A, whereas group B received sublingual buprenorphine (32.40+/-2.8 mg/day). Urine toxicological screening, plasma levels of TNF-alpha interleukin-1, interleukin-beta, lymphocyte CD14 and a self-rating depression questionnaire were measured. RESULTS: Urine screening was negative for opiates in 17.6% of group A and in 10.7% of group B (p<0.001; r = 0.62). Depression score was 62+/-2 in group A and 55+/-3 in group B (p < 0.01). Cytokine and CD14 revealed higher concentrations both in groups A and B without significant differences (p > 0.05) between the two groups. CONCLUSIONS: The effects of buprenorphine and methadone tested on the immune system were overlapping in our patients. The elevated cytokine levels observed may suggest that the two drugs stimulate immunologic hyperactivation of an immune system that was formerly inhibited by heroin. Furthermore, our data suggest that buprenorphine can be a valid alternative to methadone in maintenance treatment of chronic heroin abuse and referred a marked decline in depression.