Effects of time of day and the wingate test on appetite perceptions, food intake and plasma levels of adipokines.

It has been demonstrated that several aspects of adipose-related physiology including adipokine release, exhibit daily oscillations. Physical exercise exerts a strong influence on adipokine release and a possible reverse disruption of peripheral circadian clocks. The aim of this study was to establish the effects of time of day and the Wingate test on appetite perception, food intake and plasma levels of adipokines. Twenty-four moderately active non-smoking males (mean ± S.D. age: 27.1 ± 3.1 years; height: 1.79 ± 0.1 m; weight: 76.1 ± 11.7 kg) were recruited for this study and divided in two groups; one fed with an ad libitum test meal and another one without an ad libitum test meal. Each subject participated in the following studies performed at 11:00 and 23:00 hours on separate days: 1) Exercise study (ES): a 30-second Wingate Anaerobic Test (WAnT), and 2) sedentary study (SS). Subjects rated their appetite perceptions (hunger and prospective food consumption) on a 100-milimeter visual analogue scale (VAS) at baseline, after exercise, after test meal and during the postprandial/control period. At those time points blood samples were obtained for the measurement of plasma leptin, visfatin and apelin concentrations. Appetite perception and energy intake results at test meal decreased in response to WAnT in comparison with sedentary subjects. Time of day had no statistically significant effect on energy intake but the appetite perception score after test meal at 24:00 hours was statistically higher than that after test meal at 12:00 hours. No significant differences in the tested plasma adipokine concentrations between the trials existed at baseline, however, all plasma adipokine levels at 24:00 hours were higher than those at 12:00 hours. Plasma apelin concentrations after WAnT were significantly higher than its pre-exercise value at 12:00 hours, unlike those at 24:00 hours. Sedentary experiments showed a modest, yet significant, rise in plasma apelin levels after the test meal at 12:00 hours but not after the one at 24:00 hours. There were no significant changes in plasma leptin concentrations after exercise or test meal but a significant decrease in plasma visfatin concentrations after exercise intervention both at the 12:00 hours test and the 24:00 hours test has been observed. Test meals caused a significant rise in visfatin concentrations in sedentary, but not exercise series, in the daytime and nighttime tests. We conclude that time of day is an important aspect to consider in the relationships between exercise, metabolism and appetite. Further studies are needed to explain the specific mechanisms underlying the effects of acute exercise on postprandial physiology at different times of the day.

The usefulness of carboxyhemoglobin, methemoglobin and blood lactate concentration in evaluating the health condition of Kraków inhabitants exposed to primary pollutants.

Determination of the carboxyhemoglobin (COHb), methemoglobin (MetHb), and blood lactate concentrations is known as important contributive in evaluation of oxygen deficiency in people from urban populations. The methemoglobinemia is usually caused by unfavourable impact of NOx. A quantification of COHb allows, to some extend, to evaluate the threat of population with carbon monoxide (CO). An elevation in the blood lactate concentration indicate the oxygen insufficiency of the examined patients. The aim of this study was to evaluate the concentrations of the mentioned parameters in the three groups Kraków's population differently exposed to CO produced by incomplete combustion of carbon-containing materials. The group I consisted of 53 patients treated at the Toxicological Department for acute CO poisoning. The group II comprised 31 subjects professionally exposed to CO. The group III comprised 99 adult Kraków's inhabitants who started education in the technical school and had never been professionally exposed to CO (control group). The elevation in methemoglobin concentration was not found in any of the examined group. The highest COHb level was noted in the group of the acute CO poisoned patients. No significant difference between COHb levels was found in the chronically exposed group (II) and in the control one. The increased blood lactate concentrations were found in both the acutely CO poisoned and in the group of chronically, by occupation, exposed to CO. No unfavourable impact of Nox reflected in methemoglobinemia was noted in any examined population. The determination of COHb levels is helpful in diagnosis of acute CO poisoning. The measuring of the blood lactate concentration allows to detect the oxygen insufficiency in acute CO poisoning and in states of long-term exposure to CO.