Increased oxidative stress parameters in children with moderate iodine deficiency.

BACKGROUND: Iodine is a part of thyroid hormones and has been reported to act directly as an antioxidant or induce indirectly antioxidant enzymes. This study aimed to assess the urinary iodine concentration and its relationship between the antioxidant and oxidative stress capacity in healthy school-aged children. METHODS: In total, 196 students from five primary schools, randomly selected between 9 and 12 years (mean age: 10.2±1.2 years), were enrolled in the study. Urinary iodine levels were measured by spectrophotometry with the Sandell-Kolthoff reaction. Total antioxidant status (TAS) and total oxidant status (TOS) were analysed from urine samples. The ratio of TOS to TAS was regarded as an oxidative stress index (OSI), an indicator of the degree of oxidative status. RESULTS: Fifty-four percentage (107) of the children had iodine deficiency (ID) and the majority of them (30%) had mild ID. There was no severe-ID child in the population (<20 µg/L). Urine TAS levels were significantly lower in the moderate-ID group than in the mild-ID group (6.5±4.1 vs. 11.3±4.1 mmol, p<0.001) and the iodine-sufficient group (11.0±5.3 µmol, p<0.001). TOS levels and OSI were found higher in the moderate-ID group than in the mild-ID group (4.8±2.1 vs. 3.7±2.1 µmol, p<0.001) and the iodine-sufficient group (4.8±2.1 vs. 3.4±2.5 mmol, p<0.001). In the moderate-ID group, low urine iodine levels exhibited significant negative correlations with OSI (r=-0.660) and TOS (r=-0.248) and a positive correlation with TAS (r=0.475). CONCLUSIONS: We found that children with moderate ID were exposed to more oxidative burden than children with mild ID or iodine sufficiency. Increased systemic oxidative stress induced by moderate ID could cause development of ID-related complications and diseases. Iodine supplementation could have a beneficial role in the prevention of oxidative stress.

Oxidant stress is a significant feature of primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a chronic cholestatic disorder characterised by an immunological, and often granulomatous, attack on bile ducts leading to fibrosis, cirrhosis, liver failure and death. Animal and human studies suggest that oxidant stress plays a key role in progression of other liver diseases, but no comprehensive investigation has been performed previously in PBC. A wide range of lipid peroxidation and antioxidant markers were measured in the blood and urine of 41 patients with histologically confirmed PBC. Lipid peroxidation markers were significantly elevated [plasma and urinary 8-isoprostane, P<0.001; plasma malondialdehyde (MDA), P=0.007] compared to age- and sex-matched controls. The most striking antioxidant depletion occurred with plasma total glutathione where levels were significantly reduced (30% of controls). Total serum antioxidant levels were decreased (P=0.013) and serum selenium and vitamin A were also lower (both P<0.001); vitamins C and E were normal. Most patients had early disease biochemically and were Child-Pugh grade A. Urinary 8-isoprostane correlated positively with Ludwig stage and markers of hepatic injury and cholestasis. This study clearly demonstrates that oxidant stress, as reflected in a comprehensive spectrum of lipid peroxidation and antioxidant markers, is a significant feature of early-stage PBC.

Multivitamin solutions for enteral supplementation: a source of peroxides.

OBJECTIVE: We investigated whether solutions of enteral vitamin supplementation are involved in the generation of peroxides and whether that contamination is biologically significant. METHODS: Peroxide contents of oral multivitamin preparations were measured over 3 wk after the initial opening of the containers. In selected premature infants (younger than 35 wk gestation), urinary peroxides were measured after initiating oral multivitamin supplementation. RESULTS: Peroxides in multivitamin solutions for enteral use are predominantly organic peroxides because they resist catalase. After the initial opening of the containers, there was a two-fold increase in total peroxides levels (P < 0.05) even in the preparation without riboflavin, a catalyst for the generation of peroxides. Initiation of oral vitamin supplementation was associated with increased (P < 0.05) urine peroxide levels. The high organic peroxide load did not correlate with its urinary excretion, mostly in the form of H(2)O(2). The excretion of H(2)O(2) corresponded to its oral intake from the multivitamin solution. CONCLUSIONS: Compared with parenteral multivitamin solutions, the enteral preparations contained higher organic peroxide levels starting with the initial opening of the bottles. The increased urinary excretion of H(2)O(2) after enteral multivitamin supplementation suggested a systemic diffusion of peroxides or of components of the multivitamin preparation responsible for the generation of peroxides. This oxidant load was not quenched by the immature antioxidant defenses of premature infants.

Nutraceutical interventions may delay aging and the age-related diseases.

Largely due to better control of infectious diseases and to year-round access to a more nutritious diet, life expectancy in developed countries has increased dramatically in the twentieth century. However, as the average age of the population has risen, the incidence of chronic age-related diseases such as Alzheimer's, Parkinson's, cardiovascular disease, cancer, arthritis, osteoporosis, benign prostatic hyperplasia, late-onset diabetes, and macular degeneration have increased. To obtain further significant improvements in both lifespan and the quality of life in this century, treatments and nutritional changes that address the age-related diseases and the aging process itself need to be examined and validated. There are many reports suggesting that oxidative stress and certain nutritional deficiencies may contribute to the aging process and to many age-related diseases. In this article, we report on two human clinical trials using novel antioxidant supplements in which urinary oxidative stress is significantly reduced. We also discuss the conceptual basis and existing literature for several nutritional supplements that may have beneficial effects on aging and age-related diseases. Based on the available data, we suggest that human life expectancy can be significantly increased in the twenty-first century by optimizing diet and using nutritional supplements.