Prognostic Value of the Modified Atherogenic Index of Plasma during Body Mass Reduction in Polish Obese/Overweight People.

Although weight loss is recommended for obese patients, it remains questionable how much weight loss is optimal. A novel index that accurately determines the risk of cardiovascular diseases (CVDs) in terms of weight loss is needed. The modified Atherogenic Index of Plasma (AIP), presented here is unique in the literature. It is calculated based on data for anti-atherogenic, high-density lipoprotein cholesterol (HDL-C) fractions, instead of the total HDL-C. This study investigates whether weight loss correlates with CVD risk, and whether the modified AIP allows more accurate diagnostics in obese/overweight people. According to the increase or decrease of AIP during weight loss, 52 Polish patients were subdivided into two groups: group I (increased AIP; n = 16) and group II (decreased AIP; n = 36). The patients' body mass composition and fasting serum lipid parameters (total cholesterol, triglycerides, HDL-C, and LDL-C (low-density lipoprotein cholesterol)), and cholesterol in 21 lipoprotein sub-fractions were determined. Over six months, all patients reduced their body mass by about 10%. There were no significant differences in anthropometric measures between groups. Increases in large and intermediate HDL-C fractions 1 to 6 and decreases in smaller fractions 7 to 10 were observed in group II. In group I, HDL-C fractions 1 and 10 decreased, while cholesterol in other fractions increased. Increases were observed in the antiatherogenic HDL-C of 52% of group II and 4% of group I. As for atherogenic HDL-C, a decrease of 24% was observed in group II and an increase of 9% in group I. In group I, increases of very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and large LDL fractions were noticed, and the reverse in group II. The results show that the modified AIP is a more accurate indicator of CVD risk than existing indices, and that uncontrolled weight reduction does not necessarily have a beneficial influence, and may adversely affect the cardiovascular system.

Exercise Performance, Muscle Oxygen Extraction and Blood Cell Mitochondrial Respiration after Repeated-Sprint and Sprint Interval Training in Hypoxia: A Pilot Study.

This study aimed to investigate and compare the effects of repeated-sprint (RSH) and sprint interval training in hypoxia (SIH) on sea level running and cycling performance, and to elucidate potential common or divergent adaptations of muscle perfusion and -oxygenation as well as mitochondrial respiration of blood cells. Eleven team-sport athletes performed either RSH (3x5x10s, 20s and 5min recovery between repetitions and sets) or SIH (4x30s, 5min recovery) cycling training for 3weeks (3 times/week) at a simulated altitude of 2,200m. Before and three days after the training period, a Wingate and a repeated cycling sprint test (5x6s, 20s recovery) were performed with a 30min resting period between the tests. Four to five days after the training, participants performed a repeated running sprint test (RSA, 6x17m back and forth, 20s recovery) and a Yo-Yo intermittent recovery test (YYIR2) with 1 hour active recovery between tests. The order of the tests as well as the duration of the resting periods remained the same before and after the training period. During the cycling tests near-infrared spectroscopy was performed on the vastus lateralis. In four participants, mitochondrial respiration of peripheral blood mononuclear cells (PBMC) and platelets was measured before and after training. YYIR2 running distance increased by +96.7 ± 145.6 m after RSH and by +100.0 ± 51.6 m after SIH (p = 0.034, eta² = 0.449). RSA mean running time improved by -0.138 ± 0.14s and -0.107 ± 0.08s after RSH and SIH respectively (p = 0.012, eta² = 0.564). RSH compared to SIH improved re-oxygenation during repeated sprinting. Improvements in repeated cycling were associated with improvements in re-oxygenation (r = 0.707, p <0.05). Mitochondrial electron transfer capacity normalized per PBMC count was decreased in RSH only. This study showed that cycling RSH and SIH training improves sea-level running performance. Our preliminary results suggest that RSH and SIH training results in different patterns of muscular oxygen extraction and PBMC mitochondrial respiration, without effect on platelets respiration.

Hydroxybenzoic acids and their derivatives as peroxynitrite scavengers.

A social challenge of the 21(st) century is to reduce the incidence of chronic diseases. A balanced diet rich in polyphenols could contribute to reduce the risk and to the prevention of diabetes, coronary heart disease, cancer, Alzheimer's diseases and cataract(1). Hydroxybenzoic acids (HBA) and their derivatives, which are one of the substances responsible for these beneficial properties, are known mainly due to their antioxidant properties(2). They are effective scavengers of free radicals and reactive nitrogen species, such as peroxynitrite. Peroxynitrite is resulting from the reaction of nitric oxide with superoxide, causes lipid peroxidation and subsequent cellular damage and is responsible for the inactivation of many enzymes, activation of stress signalling pathways, release of proapoptotic factors, as well as cardiovascular dysfunction in septic schock(3). In this study we have tested 2-HBA, 3-HBA, 4-HBA, acetylsalicylic acid, 4-HBA methyl and propyl esters, 2,3-dihydroxybenzoic acid (DHBA), 2,5-DHBA, 2,4-DHBA, 2,6-DHBA, 3,5-DHBA, 3,4-DHBA, gallic acid and caffeic acid, by UV/VIS spectroscopy. The best ability to scavenge peroxynitrite was observed for gallic acid, 2,4-DHBA, 3,5-DHBA and caffeic acid. Improved comprehension of the complex relationship between the antioxidant properties of substances and their structure is important to understand their proper use in the prevention and treatment of diseases and for the detection of pathological processes. Monitoring and improved understanding of the antioxidant properties of hydroxybenzoic acid derivatives are important due to their frequent use in modern medical nutrition therapies.

Effects of humic acids in vitro.

Humic acids are known for their overall positive health and productivity effects in animal feeding trials and, controversially, as an aetiological factor of cancer. We tried to assess the in vitro effect of humic acids from a selected source in Slovakia when used at recommended prophylactic dosage. We investigated antioxidant properties, enzymatic and non-enzymatic antioxidant defence system in liver mitochondria and cultured cancer cell lines in vitro. We observed a significant decrease in superoxide dismutase activity after humic acids treatment irrespective of dissolving in dimethyl sulphoxide or direct addition to mitochondria suspension in a respiration medium. Activities of other antioxidant enzymes measured, such as glutathione peroxidase and glutathione reductase, showed no significant differences from the control as well as the reduced glutathione content. Percentage of inhibition by humic acids of superoxide radical indicated lower efficacy compared with that of hydroxyl radical. Survival of six different cancer cells lines indicated that only the acute T lymphoblastic leukaemia cell line was sensitive to the tested humic acids. Despite relatively low solubility in aqueous solutions, humic acids from the selected source participated in redox regulation. By recapturing the radicals, humic acids reloaded the antioxidant defensive mechanism. Results from in vitro study conducted with humic acids from the natural source showed potential of these substances as promising immunity enhancing agents.