Effects of antioxidant supplementation on postprandial oxidative stress and endothelial dysfunction: A single-blind, 15-day clinical trial in patients with untreated type 2 diabetes, subjects with impaired glucose tolerance, and healthy controls

BACKGROUND

Increased generation of reactive oxygen species (ROS) and oxidative stress may be of crucial importance in the pathogenesis of endothelial damage. Furthermore, there is understood to be a relationship between endothelial damage, glycemic control, disorders of lipid metabolism, and coagulative hemostatic disorders.

OBJECTIVE

This study investigated within- and between-group changes in various circulating markers of oxidation-reduction balance and endothelial function after a balanced moderate-fat meal with and without antioxidant supplementation in patients with early-stage, untreated type 2 diabetes mellitus; subjects with impaired glucose tolerance (IGT); and healthy controls.

METHODS

In this single-blind, controlled clinical study, groups of patients with type 2 diabetes and subjects with IGT were identified and compared with a group of healthy controls. All groups followed a controlled, well-balanced diet for 10 days before and throughout the study. Before and after consumption of a standardized moderate-fat meal, plasma levels of oxidants (malondialdehyde, 4-hydroxynonenal, oxidized low-density lipoprotein), the antioxidant glutathione peroxidase, and markers of endothelial function (NO, endothelin-1, von Willebrand factor [vWF], vascular cell adhesion molecule-1 [VCAM-1]) were determined. These measures were then reassessed after 15 days of standard antioxidant treatment consisting of a thiol-containing antioxidant (N-acetylcysteine 600 g/d), a bound antioxidant (vitamin E 300 g/d), and an aqueous phase antioxidant (vitamin C 250 mg/d). The efficacy of antioxidant treatment in reversing abnormalities in oxidation-reduction balance after a moderate-fat meal was assessed by evaluating changes in plasma levels of ROS on the morning of the 16th day following an overnight fast. Safety was monitored in terms of adverse events, vital signs, physical findings, and laboratory values.

RESULTS

The study included 46 patients with type 2 diabetes (23 men, 23 women; mean [SD] age, 41 [3] years; mean body mass index [BMI], 24 [2] kg/m(2)), 46 with IGT (23 men, 23 women; mean age, 39 [3] years; mean BMI, 23 [3] kg/m(2)), and 46 control subjects (23 men, 23 women; mean age, 40 [1] years; mean BMI, 22 [1] kg/m(2)). Before supplementation, all 3 groups had significantly increased levels of oxidants, vWF, and VCAM-1 (all, P < 0.001) and significantly decreased levels of antioxidants and NO (both, P < 0.001) after consumption of a moderate-fat meal. After 15 days of antioxidant treatment, significant improvements in these measures were seen in all groups (P < 0.05).

CONCLUSIONS

This study showed changes in oxidation-reduction balance, NO bioavailability, and nonthrombogenic endothelial factors after a moderate-fat meal in patients with type 2 diabetes and those with IGT, but these postprandial changes were reverse in all subjects after 15 days of standard antioxidant supplementation. These findings suggest that the use of anti-oxidants may have decreased oxidative stress in these subjects.

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.

Can ultrasonographic findings of perihepatic lymphadenopathy promote investigations to detect possible presence of virus C infection in non-symptomatic subjects?

PURPOSE: Only early detection of non-symptomatic patients is able to arrest the diffusion of the non-symptomatic HCV infection and lead to prompt treatment. Our aim was to attempt to correlate the presence of perihepatic lymph nodes and hepatitis C infection and to assess whether ultrasonography can have a role to promote specific investigations for pre-clinical diagnosis of virus C infection. METHOD: We performed a controlled study on a cohort of 7974 subjects from a town of 27000 inhabitants on the eastern coast of Sicily. Serologic hepatitis A, B and C markers, alanine aminotransferase levels and abdominal ultrasound examination according to size and number of peri-hepatic lymph nodes were performed on blind basis. RESULTS: One or more pathological lymph nodes were present in 684/7974 subjects. Haematochemical tests revealed the presence of anti-HCV positivity in 528/684 subjects with pathological lymph nodes and in 8/7290 subjects without pathological lymph nodes, there being a significant difference (P<0.0001) between the two groups. CONCLUSION: Our results confirm the association between perihepatic lymph nodes and virus C infection. Correct diagnostic assessment of this datum could lead not only to early diagnosis by specific blood test for HCV and consequent prompt aimed treatment, but could pave the way for efficacious territorial prevention and detection of an elevated percentage of likely non-symptomatic carriers.