Ekologiya cheloveka (Human Ecology)

Available publications define the objectives of biogeochemistry and introduce its key concepts: living matter and biogenic migration of chemical elements. According to studies, the biochemical parameters of living organisms depend on the geochemical environment and the content of essential elements within it. Researchers suggest that the physiological system of trace elements in living organisms serves as a structural and functional basis for metabolic processes.

Biogeochemical provinces are areas with imbalanced concentrations of chemical elements. Trace element imbalance is geochemical diseases in humans and animals, with defined mechanisms of formation. Evidence shows that both deficiencies and excess of bioelements in the human body contribute to psychosomatic disorders, such as lifestyle diseases, reduced fertility, an increase in infertile marriages, and various forms of deviant behavior.

Regional biogeochemical research is needed to study the distribution of chemical elements in the environment, plants, animals, and the human body. The natural and climatic conditions and the biogeochemical profile of northern regions are still poorly studied, particularly with regard to the elemental status of residents in the Arctic areas. Low levels of essential elements in the biosphere of the North create a biological burden for the population and contribute to an increased risk of trace element imbalance. Studies have identified common features of elemental status among residents of both the Asian and European North, including widespread deficiencies of cobalt, selenium, calcium, and iodine. Among migrants to the North, lower levels of iron, selenium, and fluoride lead to an acclimatization-related deficiency of these elements.

The published data also indicates that the biosphere of the North is polluted. Arctic contamination affects soil and vegetation, drinking water, and leads to bioaccumulation of toxic elements such as mercury, lead, cadmium, and arsenic in living organisms.

Nutritional patterns in the North are characterized by a reduced share of traditional food products in the local diet. The natural deficiency of essential elements, enhanced by the loss of biologically valuable nutrition, contributes to further deficiency of iron, zinc, cobalt, copper, manganese, iodine, and selenium, reducing the human body’s adaptive potential in northern conditions.

An analysis of ecological and medical issues related to iodine allows clarifying its physiological role, assessing iodine sufficiency among the Russian population, identifying iodine deficiency as a public health concern, and proposing corrective measures.

In conclusion, maintaining the health of northern populations requires biogeochemical monitoring of Arctic regions, identification of territories predisposed to biogeochemical endemics, and prevention of diseases of geochemical origin.

Background: Heart rate variability in athletes exhibits sex-related differences.

Aim: The work aimed to study sex-related characteristics of heart rate variability in cross-country skiers.

Methods: During the general preparatory training period, 289 male and 113 female athletes aged 18–32 years from the Republic of Komi national cross-country skiing teams with sports qualification of at least first category were assessed. A 5-minute electrocardiogram (ECG) recording was obtained in the supine position, and heart rate variability was analyzed using the Ecosan-2007 hardware-software system (Medical Computer Systems, Russia). Statistical significance of intergroup differences was evaluated using the Mann–Whitney U test.

Results: Significant differences in several heart rate variability parameters were found in athletes of both sexes. Compared with women, men exhibited higher values of mode (Mo) (p <0.001), mean RR interval (p <0.001), maximum (Max) (p <0.001) and minimum (Min) (p <0.001) RR intervals, and the relative (%) power of the high-frequency spectrum (p=0.023). Women showed higher heart rate (p <0.001), the Max/Min RR ratio (MxRMn) (p=0.02), low-frequency to high-frequency ratio (p=0.038), and index of centralization (p=0.022).

Conclusion: Cross-country skiers demonstrate sex-specific features of autonomic heart rate regulation. Compared with female athletes, male exhibit a more economical mechanism of autonomic regulation of heart rhythm and a more pronounced shift in autonomic balance toward the parasympathetic nervous system.

Background: The existing universal standardization system for simple visual-motor reaction parameters does not account for the physical and geographical characteristics of a person’s place of residence or their sex. Investigating the influence of physical and geographical factors on manifestations of simple sensorimotor reaction may help objectify the assessment of the functional state of the central nervous system (CNS) in individuals.

Aim: The work aimed to characterize the specific manifestations of simple sensorimotor reaction parameters in residents of the northern and southern regions of the European part of Russia.

Methods: The study included 64 clinically healthy men and women of European descent aged 19–23 years, indigenous residents of the Arkhangelsk Region and the Volgograd Region. Using the UPFT-1/30 Psychophysiologist device, the following basic and integral parameters of simple visual-motor reaction were analyzed: minimum reaction time, maximum reaction time, mean reaction time, median, number of anticipatory reactions, accuracy level, stability level, response speed level, CNS activation level, and the integral characteristic “classification squares.”

Results: A high level of CNS activation, which systematically reflects the speed and stability of sensorimotor responses, ensures a pronounced functional potential in men from southern regions, despite a slight imbalance in the nervous system due to predominant excitation processes. In contrast, men from northern regions exhibited opposite neurodynamic properties: reduced CNS activation, predominance of inhibitory processes, slower reaction speed, increased response stability and higher sensorimotor accuracy.

The analysis of the parameters revealed differences between men and women depending on place of residence: among residents of the northern regions, simple visual-motor reaction values were nearly identical in both sexes. Among southern residents, women had statistically significantly longer mean reaction times (p = 0.02) and medians (p = 0.05) compared with men. Overall, no statistically significant differences in simple visual-motor reaction parameters were observed between women from northern and southern regions.

Conclusion: The findings confirm that physical and geographical factors influence the functional state of the CNS. The study characterizes the specific features of simple sensorimotor reaction parameters in men and women from the northern and southern regions of the European part of Russia. Considering the birthplace, place of residence, and sex enables personalized standardization of simple visual-motor reaction assessment results.

Background: Glaucoma is considered one of the leading causes of disability. Intraocular pressure is a key risk factor for the development of glaucoma, which underscores the importance of its assessment and control. The pneumotonometric method for measuring intraocular pressure is being widely used in glaucoma screening diagnostics.

Aim: The work aimed to determine population-based reference values and age-related changes in intraocular pressure among adults in the European North of Russia and to examine associations between intraocular pressure and socio-demographic characteristics, lifestyle factors, and health indicators.

Methods: A random sample of Arkhangelsk residents aged 45–74 years (n = 1223) was examined, including an ophthalmologic assessment and pneumotonometry. Socio-demographic and lifestyle data were collected via face-to-face interviews, and health characteristics were obtained through clinical examinations. Reference intraocular pressure values were defined using the 5th and 95th percentiles. Associations between intraocular pressure and study variables were assessed using multivariable linear regression and presented as B coefficients with 95% confidence intervals (CI).

Results: The mean intraocular pressure was 14.2 mmHg overall, 13.9 mmHg in men, and 14.4 mmHg in women. Population-based reference ranges for true intraocular pressure were identified as follows: low-normal (9–12 mmHg), mid-normal (12–16 mmHg), and high-normal (16–20 mmHg). Intraocular pressure levels showed a downward trend with increasing age in both women (p = 0.007) and men (p = 0.011). Inverse associations were found between intraocular pressure and male sex (B = –0.56; 95% CI: –0.94 to –0.18), indigenous status in the Arkhangelsk Region (B = –0.50; 95% CI: –0.83 to –0.16), and higher education (B = –0.40; 95% CI: –0.73 to –0.06). Among health-related variables, intraocular pressure was associated with hypertension (B = 0.56; 95% CI: 0.17 to 0.94), diabetes mellitus (B = 0.46; 95% CI: 0.03 to 0.89), dyslipidemia (B = 0.36; 95% CI: 0.01 to 0.71), abdominal obesity (B = 0.39; 95% CI: 0.31 to 0.98), thyroid dysfunction (B = 0.42; 95% CI: 0.07 to 0.77), vitamin D deficiency (B = 0.76; 95% CI: 0.30 to 1.22), and low serum total protein (B = –0.76; 95% CI: –1.43 to –0.09).

Conclusion: This study established normal intraocular pressure ranges for residents of the European North of Russia aged 45–74 years. A decrease in intraocular pressure with age was observed, along with lower intraocular pressure levels in men, indigenous residents of the Arkhangelsk Region, and individuals with low serum protein. Elevated intraocular pressure levels were associated with hypertension, diabetes mellitus, dyslipidemia, obesity, thyroid dysfunction, and vitamin D deficiency.