Metabolic, Cardiac, and Hemorheological Responses to Submaximal Exercise under Light and Moderate Hypobaric Hypoxia in Healthy Men

We compared the effects of metabolic, cardiac, and hemorheological responses to submaximal exercise under light hypoxia (LH) and moderate hypoxia (MH) versus normoxia (N). Ten healthy men (aged 21.3 ± 1.0 years) completed 30 min submaximal exercise corresponding to 60% maximal oxygen uptake at normoxia on a cycle ergometer under normoxia (760 mmHg), light hypoxia (596 mmHg, simulated 2000 m altitude), and moderate hypoxia (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in a random order. Metabolic parameters (oxygen saturation (SPO2), minute ventilation, oxygen uptake, carbon dioxide excretion, respiratory exchange ratio, and blood lactate), cardiac function (heart rate (HR), stroke volume, cardiac output, and ejection fraction), and hemorheological properties (erythrocyte deformability and aggregation) were measured at rest and 5, 10, 15, and 30 min after exercise. SPO2 significantly reduced as hypoxia became more severe (MH > LH > N), and blood lactate was significantly higher in the MH than in the LH and N groups. HR significantly increased in the MH and LH groups compared to the N group. There was no significant difference in hemorheological properties, including erythrocyte deformability and aggregation. Thus, submaximal exercise under light/moderate hypoxia induced greater metabolic and cardiac responses but did not affect hemorheological properties.

Effects of daytime ingestion of melatonin on heart rate response during prolonged exercise

The current study sought to investigate the effect of melatonin consumption on cardiovascular response during submaximal exercise in healthy men. For this purpose, eight students (age: 21.8 ± 0.9) were asked to run for 45 minutes at submaximal intensity after melatonin-(6 mg) or placebo-ingestion, in a randomized and counterbalanced order. Heart rate (HR) and rectal temperature (Tre) evolution during exercise were measured. Blood samples were drawn twice (before and immediately after exercise) for the determination of triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-c), lactate, protein, and superoxide dismutase concentrations. The results showed that melatonin may disturb thermoregulatory control by exerting an effect on HR at 10 min of exercise, reducing HR by 6.6% (9 bpm; P < 0.001), and this effect decreased to 3.6% at the end of exercise (P < 0.01). Melatonin has no effect on triglycerides total cholesterol, HDL-c, lactate, and protein at rest and post-exercise. Although melatonin administration did not present a risk for cardiovascular function in healthy men, melatonin at high doses could decrease superoxide dismutase concentrations owing to the alteration of redox balance. These findings suggest that a high concentration of antioxidants does not enhance cardiovascular performance and may impair thermoregulatory control during prolonged exercise.

Characterization of the LPS and 3OHFA Contents in the Lipoprotein Fractions and Lipoprotein Particles of Healthy Men

Atherosclerosis is a chronic inflammatory disease that is caused by the accumulation of LDL particles in the intima, causing the activation of immune cells and triggering an inflammatory response. LPS is a potent activator of the innate immune response and it can be transported by lipoproteins. Since humans are much more sensitive to LPS than other mammals, and very low amounts of LPS can elicit an immune response, the aim of this study is to characterize the distribution of LPS and its immunogenic portion (3OHFAs) among lipoprotein types of healthy men. We separated lipoprotein fractions by ultracentrifugation and the amount of each 3OHFA was measured by MS in each lipoprotein fraction to calculate LPS concentration. Lipoprotein particle concentration was measured by NMR. LDL and HDL fractions transported the highest concentration of LPS (35.7% and 31.5%, respectively), but VLDL particles carried more LPS molecules per particle (0.55 molecules/particle) than LDL or HDL (p < 0.01). The distribution of LPS and all 3OHFAs among lipoprotein fractions showed high interindividual variability, suggesting that they may be studied as a potential biomarker. This may help understand the role of LPS in atherosclerosis in those cases where the disease cannot be explained by traditional risk factors.

Girth body dimensions in men and women with seborrheic dermatitis of varying severity

Today in modern medicine the study of human health is reoriented to the individual principle, which is based on the identification and study of constitutionally determined patterns of manifestation of certain diseases. The purpose of the study is to establish and analyze the features of the girth body sizes in men and women with generalized fatty form of seborrheic dermatitis of varying severity. The comprehensive body size of 40 men and 40 young women (25-44 years) with generalized fatty seborrheic dermatitis (mild and severe) was determined. The control group consisted of the girth sizes of practically healthy men (n=82) and women (n=154) of the same age group, which were selected from the database of the research center National Pirogov Memorial Medical University. Statistical processing of body circumference was performed in the licensed package “Statistica 6.0” using non-parametric evaluation methods. As a result of studies in patients with seborrheic dermatitis of varying severity of men, compared with practically healthy men, found only greater values of the girth of the shoulder in a relaxed state and thighs, neck (only mild), shin in the upper part and waist (in both cases only with a severe degree), as well as smaller values of the girth of the shoulder in a tense state; and in patients of varying severity of women – greater values of the girth of the shoulder in a relaxed state, thighs, lower legs, neck, waist and all girths of the chest and both thighs (only severe), as well as smaller values of the girth of the hand (only with mild). In both men and women with seborrheic dermatitis, differences in girth body sizes are more pronounced in people with severe disease. Between men or women with seborrheic dermatitis of varying severity, there are no significant or trends in differences in girth body sizes. In the analysis of the manifestations of sexual dimorphism of the circumferential body size between men and women with seborrheic dermatitis found greater values in men with mild and severe disease of the upper extremities, hands, shin, feet and neck (in most cases more pronounced in representatives with mild severity), as well as only in men with mild severity – greater values of all chest girths. For a more correct understanding of changes in girth body sizes in Ukrainian men or women with seborrheic dermatitis of varying severity, it is necessary to analyze other constitutional parameters of the body.

Features of skinfold thickness in men with benign nevi

Nevi, although benign neoplasms of the skin, but have a certain tendency to malignancy, which is influenced by various external and internal human factors. Predicting the risk of benign nevi against this background is an important topic for experimental research. The aim of the study was to establish the features of the skinfold thickness (SFT) in men of the first adult age with benign nevi. SFT was determined according to the Bunak scheme for men (aged 22-35 years) with melanocyte benign simple nevi (n=34), melanocyte benign dysplastic nevi (n=27), melanocyte benign congenital nevi (n=14) and non-melanocyte benign (n=17). The control group – SFT of 82 practically healthy men of the same age group was selected from the data bank of the Research Center of National Pirogov Memorial Medical University, Vinnytsya. Statistical processing of the results was performed in the license package “Statistica 5.5” using non-parametric evaluation methods. It was found that in practically healthy men higher than in patients – SFT on the anterior and posterior surfaces of the shoulder and thigh (in all groups of patients); SFT on the forearm, at the lower angle of the scapula, chest and shin (only in patients with melanocyte benign dysplastic nevi). Also in healthy men are found lower than in patients – SFT on the side (in all groups of patients); SFT in the abdomen (in patients with melanocyte benign simple and non-melanocyte benign nevi). When comparing SFT between patients with benign nevi, in most cases, lower values of SFT found in patients with melanocyte benign dysplastic nevi. The obtained results indicate the initial manifestations of abdominal (android) type of fat deposition in the body in patients with benign nevi (most pronounced in patients with melanocyte benign simple nevi).