M. L. Sasonko

[Evaluation of the hypomagnetic environment effects on capillary blood circulation, blood pressure and heart rate].

The impact of attenuated magnetic field (МF) on human health is a burning issue of present-day cosmonautics. A series of experiments with animals exposed to attenuated MF revealed violent disorders in the development of the cardiovascular system. The purpose of this study was to estimate the effects of hypomagnetic environment (HME) on capillary blood circulation, blood pressure (BP), and heart rate (HR) in healthy humans. Participants (n = 34) were 24 men and 10 women without cardiovascular symptoms. The mean age was 43.3 ± 15.4 years. Thirteen participants, eight men and five women, were randomly selected for a repeated investigation under natural conditions (sham exposure). The mean age in this group was 47.9 ± 18 years. Cardiac rhythm and heart rate were recorded using an Astrocard cardiac monitor (Russia). BP was measured by means of a Tonocard automatic blood pressure monitor (Russia). Capillary circulation was determined using a digital capillaroscope (Russia) with a high-speed CMOS camera (100 frames/s). The duration of HME exposure was 60 min. It has been demonstrated that HME increases capillary circulation rate by 22.4% in healthy humans without cardiovascular symptoms as compared to the records made under natural conditions. There was a significant HR reduction by the end of HME exposure as compared to the measurements taken at the beginning. At the end of the exposure, diastolic BP dropped considerably relative to mid-exposure values; on the contrary, systolic BP significantly increased by the end.

Implementation of digital optical capillaroscopy for quantifying and estimating the microvascular abnormalities in type 2 diabetes mellitus

This study is aimed to define the extent of digital capillaroscopy possibilities for the quantification and estimation of microvascular abnormalities in type 2 diabetes mellitus (T2DM). A total of 196 adult persons were enrolled in the study including the group of compensated T2DM (n = 52), decompensated diabetics (n = 68), and healthy volunteers (n = 76) with normal blood glucose and without signs of cardiovascular pathology. All participants of the study were examined with the digital optical capillaroscope (“AET”, Russia). This instrument is equipped with an image-processing program allowing for quantifying the diameters of the arterial and venous segments of the capillaries and their ratio (coefficient of remodeling), perivascular zone size, capillary blood velocity, and the degree of arterial loops narrowing and the density of the capillary network. Also we estimated the relative amount of coil-shaped capillaries. The study revealed significant difference in the capillary density and the remodeling coefficient in comparison of T2DM patients with non-diabetic individuals. Significant changes are found in the decompensated T2DM group compared to the compensated group of diabetic patients. Furthermore, the number of coil-shaped capillaries differed greatly in T2DM patients as compared to the healthy subjects. The study did not reveal any statistically significant differences in the capillary density between the patients with compensated and decompensated T2DM. The digital optical capillaroscope equipped with the advanced image-processing algorithm opens up new possibilities for obtaining clinically important information on microvascular abnormalities in patients suffering from diabetes mellitus.

Geomagnetic storm under laboratory conditions: randomized experiment

The influence of the previously recorded geomagnetic storm (GS) on human cardiovascular system and microcirculation has been studied under laboratory conditions. Healthy volunteers in lying position were exposed under two artificially created conditions: quiet (Q) and storm (S). The Q regime playbacks a noise-free magnetic field (MF) which is closed to the natural geomagnetic conditions on Moscow’s latitude. The S regime playbacks the initially recorded 6-h geomagnetic storm which is repeated four times sequentially. The cardiovascular response to the GS impact was assessed by measuring capillary blood velocity (CBV) and blood pressure (BP) and by the analysis of the 24-h ECG recording. A storm-to-quiet ratio for the cardio intervals (CI) and the heart rate variability (HRV) was introduced in order to reveal the average over group significant differences of HRV. An individual sensitivity to the GS was estimated using the autocorrelation function analysis of the high-frequency (HF) part of the CI spectrum. The autocorrelation analysis allowed for detection a group of subjects of study which autocorrelation functions (ACF) react differently in the Q and S regimes of exposure.

The Effects of Space and Terrestrial Weather Factors on Arterial Stiffness and Endothelial Function in Humans

A differential evolution algorithm was used to detect the biotropic influence of geomagnetic activity on several parameters of human vascular tone. Studies of the characteristics of vascular tone in healthy volunteers showed that arterial stiffness and endothelial function, as well as blood pressure and heart rate, depend on the geomagnetic and, in most cases, weather conditions. The pulse wave velocity (PWV) was measured to characterize the arterial stiffness and was found to be the most sensitive to the effects of space weather parameters. The strength of the effect of geomagnetic activity was for the first time observed to depend on the configuration of terrestrial weather parameters. A linear correlation between the K index of geomagnetic activity and PWV was estimated at r =–0.44 (p = 0.0003), although the relationship was detectable exclusively in the case of certain terrestrial weather parameters. Endothelial dysfunction and the pulse-rate response to variations in geomagnetic activity implicated nitrogen monoxide in body adaptation to variations in geomagnetic activity.

Параметры микроциркуляции при компенсированном и декомпенсированном сахарном диабете 2-го типа

AIM To reveal the features of microcirculatory parameters in compensated and decompensated type 2 diabetes mellitus (T2DM). SUBJECTS AND METHODS A total of 196 patients with T2DM were examined and divided into 2 groups: 1) 52 patients (40.4% of men) aged 52.8±8.7 years with compensated T2DM (glycated hemoglobin (HbA1с), 6.3±0.5%); 2) 68 patients (38.2% of men) aged 52.8±8.1 years with decompensated T2DM (HbA1с, 9.4±1.7%). Both patient groups had concomitant hypertension (its prevalence, degree, stage of hypertension were comparable). A control group consisted of 76 volunteers (40.8% of men) aged 52.2±8.7 years with normal carbohydrate metabolism and without signs of cardiovascular disease (HbA1с, 5.3±0.49%). Capillary blood flow in the finger nail-fold area was investigated in all the participants. A digital optical capillaroscope with image-processing software was used to obtain quantitative blood microcirculatory parameters. The diameters of arterial and venous capillary segments were measured, by calculating the remodeling rate. The degree of capillary tortuosity, network density, and polymorphism and the size of the perivascular zone (PZ) were estimated. Blood rheological properties and capillary blood flow velocity were also investigated. RESULTS The decompensated T2DM group compared to the compensated T2DM group was found to have a narrowing of the arterial capillary segment diameter (8.4±2.0 µm; p=0.009) and an increase in remodeling rates (1.47±0.22; p=0.000). The tendency of the PZ size to be larger in patients with decompensated T2DM compared to those with compensated T2DM (p=0.080) and the increase in this indicator compared to the control group (p=0.001) reflect the presence of edema syndrome in Group 2, as laboratory confirmed by a statistically significantly elevated sodium level (p=0.000; p=0.006). The enlarged venous capillary segment demonstrates involvement of the venous component in microcirculatory disorders in T2DM. The reduction in the density of the capillary network and the increase in capillary tortuosity and polymorphism, which were also observed in the patients of both groups versus the control group, are referred to as disorders that are characteristic of T2DM. CONCLUSION In decompensated T2DM, capillary bed structural and functional changes are found as a narrowing of the arterial capillary segment, an increase in the rate of remodeling, and enlargement of the PZ. Digital capillaroscopy opens up new possibilities for assessing the magnitude of changes in the microcirculatory system in DM and can simultaneously evaluate the efficiency of treatment, by monitoring the status of the microvasculature.