Gut Microbiota Patterns in Patients with Non-Alcoholic Fatty Liver Disease: A Comprehensive Assessment Using Three Analysis Methods

Non-alcoholic fatty liver disease (NAFLD) is considered the most common chronic liver disease worldwide, affecting nearly 25% of the global adult population. Increasing evidence suggests that functional and compositional changes in the gut microbiota may contribute to the development and promote the progression of NAFLD. 16S rRNA gene next-generation sequencing is widely used to determine specific features of the NAFLD microbiome, but a complex system such as the gut microbiota requires a comprehensive approach. We used three different approaches: MALDI-TOF-MS of bacterial cultures, qPCR, and 16S NGS sequencing, as well as a wide variety of statistical methods to assess the differences in gut microbiota composition between NAFLD patients without significant fibrosis and the control group. The listed methods showed enrichment in Collinsella sp. and Oscillospiraceae for the control samples and enrichment in Lachnospiraceae (and in particular Dorea sp.) and Veillonellaceae in NAFLD. The families, Bifidobacteriaceae, Lactobacillaceae, and Enterococcaceae (particularly Enterococcus faecium and Enterococcus faecalis), were also found to be important taxa for NAFLD microbiome evaluation. Considering individual method observations, an increase in Candida krusei and a decrease in Bacteroides uniformis for NAFLD patients were detected using MALDI-TOF-MS. An increase in Gracilibacteraceae, Chitinophagaceae, Pirellulaceae, Erysipelatoclostridiaceae, Muribaculaceae, and Comamonadaceae, and a decrease in Acidaminococcaceae in NAFLD were observed with 16S NGS, and enrichment in Fusobacterium nucleatum was shown using qPCR analysis. These findings confirm that NAFLD is associated with changes in gut microbiota composition. Further investigations are required to determine the cause-and-effect relationships and the impact of microbiota-derived compounds on the development and progression of NAFLD.

Parameters of cutaneous microvasculature in men of working age with newly diagnosed arterial hypertension

OBJECTIVE

To investigate structural and functional features of cutaneous microvasculature in men of working age with newly diagnosed arterial hypertension (AH).

MATERIALS AND METHODS

The study included 161 apparently healthy men from 30 to 60 years, who underwent a comprehensive examination of cardiovascular system "from the heart to the capillaries". Control group (CG) included 60 normotensive men. AH group included 101 men with elevated BP.

RESULTS

There is no rarefaction of the capillary bed and latent fluid retention in the interstitial space in the skin in men with AH. No data were obtained for increased endothelial, neurogenic and myogenic tone of resistive cutaneous precapillary arterioles in AH group, but a decrease in the perfusion efficiency of the endothelial and myogenic mechanisms of tissue perfusion modulation was noted.

CONCLUSION

Obtained results allow making the assumption that metabolic disorders at the level of capillaries that are of a systemic nature prevail in men with the onset of AH.

Growth Hormone, Insulin-Like Growth Factor-1, Insulin Resistance, and Leukocyte Telomere Length as Determinants of Arterial Aging in Subjects Free of Cardiovascular Diseases

Background: Increased arterial stiffness (AS), intima-media thickness (IMT), and the presence of atherosclerotic plaques (PP) have been considered as important aspects of vascular aging. It is well documented that the cardiovascular system is an important target organ for growth hormone (GH) and insulin-like growth factor (IGF)-1 in humans, and GH /IGF-1 deficiency significantly increases the risk for cardiovascular diseases (CVD). The telomere length of peripheral blood leukocytes (LTL) is a biomarker of cellular senescence and that has been proposed as an independent predictor of (CVD). The aim of this study is to determine the role of GH/IGF-1, LTL and their interaction cardiovascular risk factors (CVRF) in the vascular aging. Methods: The study group included 303 ambulatory participants free of known CVD (104 males and 199 females) with a mean age of 51.8 ± 13.3 years. All subjects had one or more CVRF [age, smoking, arterial hypertension, obesity, dyslipidemia, fasting hyperglycemia, insulin resistance-HOMA (homeostatic model assessment) >2.5, or high glycated hemoglobin]. The study sample was divided into the two groups according to age as "younger" (m ≤ 45 years, f ≤ 55 years) and "older" (m > 45 years, f > 55 years). IMT and PP were determined by ultrasonography, AS was determined by measuring the carotid-femoral pulse wave velocity (c-f PWV) using the SphygmoCor system (AtCor Medical). LTL was determined by PCR. Serum IGF-1 and GH concentrations we measured by immunochemiluminescence analysis. Results: Multiple linear regression analysis with adjustment for CVRF indicated that HOMA, GH, IGF-1, and LTL had an independent relationship with all the arterial wall parameters investigated in the younger group. In the model with c-f PWV as a dependent variable, p < 0.001 for HOMA, p = 0.03 for GH, and p = 0.004 for LTL. In the model with IMT as a dependent variable, p = 0.0001 for HOMA, p = 0.044 for GH, and p = 0.004 for IGF-1. In the model with the number of plaques as a dependent variable, p = 0.0001 for HOMA, and p = 0.045 for IGF-1. In the older group, there were no independent significant associations between GH/IGF-1, LTL, HOMA, and arterial wall characteristics. Conclusions: GH/IGF-1, IR, HOMA, and LTL were the important parameters of arterial aging in younger healthy participants.

Atorvastatin Therapy Modulates Telomerase Activity in Patients Free of Atherosclerotic Cardiovascular Diseases

Background: Telomerase activity (TA) is considered as the biomarker for cardiovascular aging and cardiovascular diseases (CVDs). Recent studies suggest a link between statins and telomere biology that may be explained by anti-inflammatory actions of statins and their positive effect on TA. Until now, this effect has not been investigated in prospective randomized studies. We hypothesized that 12 months of atorvastatin therapy increased TA in peripheral blood mononuclear cells. Methods: In a randomized, placebo-controlled study 100 hypercholesterolemic patients, aged 35-75 years, free of known CVDs and diabetes mellitus type 2 received 20 mg of atorvastatin daily or placebo for 12 months. TA was measured by quantitative polymerase chain reaction. Results: At study end, 82 patients had sufficient peripheral blood mononuclear cells needed for longitudinal analysis. TA expressed as natural logarithms changed from 0.46 ± 0.05 to 0.68 ± 0.06 (p = 0.004) in the atorvastatin group and from 0.67 ± 0.06 to 0.60 ± 0.07 (p = 0.477) in the control group. In multiple regression analysis, atorvastatin therapy was the only independent predictor (p = 0.05) of the changes in TA independently of markers of chronic inflammation and oxidative stress. Atorvastatin therapy was associated with increases in interleukin-6 within the normal range and a tendency toward reduction in blood urea. Conclusion: These initial observations suggest atorvastatin can act as telomerase activator and potentially as effective geroprotector. Trial registration: The trial was registered in ISRCTN registry ISRCTN55050065.

[The age-related changes of the heart rate variability measurements: the role of the inflammation, oxidative stress and telomeres biology]

The autonomic and central nervous system, a number of humoral and reflex effects regulate the heart rate. The main role in the heart rate regulation belongs to the autonomic nervous system. A common method for studying the autonomic influences on the heart rate is the analysis of heart rate variability (HRV), which allows to evaluate the neuro-vegetative status of the organism, determine its adaptive capacity, to evaluate the level of stress and the degree of tension of regulatory systems. An age-related decrease of HRV measurements in healthy people reflects the weakening of the autonomic regulation of cardiac activity. The most pronounced changes are found in patients older than 60 years. The HRV depression is preceded by hemodynamic and metabolic disorders is associated with high cardiovascular risk and is a predictor of life-threatening arrhythmias and sudden death in the elderly.The reasons for HRV changes with age stay unclear. In the light of modern ideas about the mechanisms of aging, several complementary theories proposed. Telomere shortening, the role of oxidative stress and inflammation as possible mechanisms of age-related changes in the autonomic regulation of the heart rhythm, will be discussed in this article.

[Association of renal function, telomere length and markers of chronic inflammation for patients without chronic kidney and cardiovascular diseases]

Most of people over 60 years of age have decreased renal function and the velocity of glomerular filtration rate reduction varies greatly. Presumably, one of the probable mechanisms of accelerated decline of renal function may be a shortening of telomere length due to chronic inflammation. The main purpose of research was to appreciate the association of renal function, leukocytes telomeres length and markers of chronic inflammation in patients without chronic kidney disease and cardiovascular disease. 253 patients without chronic kidney diseases and cardiovascular diseases were included in the study. The average age of patients was 51,5±13,3 years. There were 172 women and 81 men. 55 patients had hypertension of 1-2 degree, 46 patients had normal renal function, 207 had mild failure of kidney function. Albuminuria was < 30 mg/day in all patients. Multivariate linear regression analysis revealed statistically significant correlation between albuminuria level and telomere length (p=0,023), C reactive protein (p=0,047) and fibrinogen (p=0,001). Glomerular filtration rate, urea and creatinine were not associated with telomere length and markers of inflammation but were correlated well with age, p < 0,001.

CONCLUSIONS

Albuminuria is mainly associated with chronic inflammation and telomere length (from all studied indices of renal function). Albuminuria may be regarded as a marker of replicative cell senescence and a therapeutic target for the prevention of renal function reduction.

Short telomere length is associated with arterial aging in patients with type 2 diabetes mellitus

It is known that glucose disturbances contribute to micro- and macrovascular complications and vascular aging. Telomere length is considered to be a cellular aging biomarker. It is important to determine the telomere length role in vascular structural and functional changes in patients with diabetes mellitus. We conducted a cross-sectional observational study in a high-risk population from Moscow, Russia. The study included 50 patients with diabetes and without clinical cardiovascular disease and 49 control group participants. Glucose metabolism assessment tests, measuring intima-media complex thickness and determining the presence of atherosclerotic plaques, pulse wave velocity measurement, and telomere length measurement were administered to all participants. Vascular changes were more dramatic in patients with diabetes than in the control group, and the telomeres were shorter in patients with diabetes. Significant differences were found in the vascular wall condition among diabetes patients, and there were no substantial differences in the arterial structure between patients with 'long' telomeres; however, there were statistically significant differences in the vascular wall condition between patients with 'short' telomeres. Vascular ageing signs were more prominent in patients with diabetes. However, despite diabetes, vascular changes in patients with long telomeres were very modest and were similar to the vascular walls in healthy individuals. Thus, long lymphocyte telomeres may have a protective effect on the vascular wall and may prevent vascular wall deterioration caused by glucose metabolism disorders.

[Age-related Changes of Left Ventricular Diastolic Function, NT-proBNP Level and Their Association with Leukocyte Telomere Length]

With advancing age the left ventricle (LV) undergoes structural and functional changes, thereby creating the substrate for the development of diseases. One possible mechanism of the ageing of the heart is cellular senescence. Leukocyte telomere length (LTL) is a marker of replicative ageing. The purpose of this study was to evaluate the diastolic function of LV and level of NT-proBNP in people of different ages free of cardiovascular diseases and to assess their relationship with LTL. Our data showed that old age is associated with diastolic dysfunction and increase in the levels of NT-proBNP. The group of older subjects had lower values of E/A (0.96+/-0.036 vs 1.27+/-0.03, p<0.001), Em/Am (0.9+/-0.035 vs 1.5+/-0.066) and higher values of IVRT (81+/-1.56 vs 70+/-1.23 s, p<0.001), DT (198+/-3.98 vs 175+/-2.82 s, p<0.001), that reflected impairment of LV relaxation. NT-proBNP level was higher in the elderly (100.82+/-7.1 vs 48.47+/-6.7 g/ml, p<0.01), but it did not correlate with LTL. The most sensitive to the age parameters of LV diastolic function (E/A and Em/Am ratio) were positively and independently of age associated with LTL (p<0.001). Older individuals with shorter LTL had significantly lower values of E/A ratio.

CONCLUSION

Telomere length appears to be a biomarker of myocardium ageing.

[Age-related Changes of Left Ventricular Diastolic Function, NT-proBNP Level and Their Association With Leukocyte Telomere Length]

With advancing age the left ventricle (LV) undergoes structural and functional changes, thereby creating the substrate for the development of diseases. One possible mechanism of the ageing of the heart is cellular senescence. Leukocyte telomere length (LTL) is a marker of replicative ageing. The purpose of this study was to evaluate the diastolic function of LV and level of NT-proBNP in people of different ages free of cardiovascular diseases and to assess their relationship with LTL. Our data showed that old age is associated with diastolic dysfunction and increase in the levels of NT-proBNP. The group of older subjects had lower values of E/A (0.96 ± 0.036 vs 1.27 ± 0.03, p < 0.001), Em/Am (0.9 ± 0.035 vs 1.5 ± 0.066) and higher values of IVRT (81 ± 1.56 vs 70 ± 1.23 MS, p < 0.001), DT (198 ± 3.98 vs 175 ± 2.82 MS, p < 0.001), that reflected impairment of LV relaxation. NT-proBNP level was higher in the elderly (100.82 ± 7.1 vs 48.47 ± 6.7 ωg/ml, p < 0.01), but it did not correlate with LTL. The most sensitive to the age parameters of LV diastolic function (E/A and Em/Am ratio) were positively and independently of age associated with LTL (p < 0.001). Older individuals with shorter LTL had significantly lower values of E/A ratio.

CONCLUSION

Telomere length appears to be a biomarker of myocardium ageing.

[Dabigatran in the prevention of stroke in nonvalvular atrial fibrillation: complex clinical situations and real clinical practice]

It is well known that there is a 5-fold increase in the incidence of strokes and systemic thromboembolic events in atrial fibrillation (AF) and anticoagulant therapy considerably reduces the risk of their development. Until recently, warfarin has been mainly used for this purpose. Dabigatran is the first representative of new-generation oral anticoagulants from a class of direct thrombin inhibitors to treat nonvalvular AF. Unlike warfarin, the drug provides a predictable and steady-state anticoagulant effect. This review presents the main pharmacological characteristics of dabigatran, the possibilities of its use in complex clinical situations in patients with AF in cardioversion, ablation, surgical/invasive interventions, hemorrhage, myocardial infarction, and stroke, as well as data on the use of the drug in real clinical practice.

[The renin-angiotensin-aldosterone system and vascular aging]

In this paper we discuss the role of renin-angiotensin-aldosterone system in development of morphological and functional changes in the vascular aging as well as, possibility of its correction by using different groups of drugs.

[Broken heart syndrome or Takotsubo cardiomyopathy. (Literature review and clinical observations)]

Takotsubo cardiomyopathy is an acute cardiac syndrome that mimics ST segment elevation myocardial infarction. It is characterized by transient local contractility disturbances as akinesis of the apical and middle segments of the left ventricle concurrent with hyperkinesis of its basal portions in the absence of significant coronary artery changes. A description of 2 clinical cases and a review of literature on this rare myocardial disease are given.

[Spontaneous reperfusion of the infarct-related artery in patients with ST elevated myocardial infarction]

AIM

To characterize a clinical course of ST elevation myocardial infarction (STEMI) and spontaneous reperfusion of the coronary arteries (SR) as well as in patients after reperfusion thrombolytic therapy (TLT) and/or transluminal balloon coronary angioplasty (TBCA); to compare effectiveness of different approaches to treatment of SR patients: conservative--early medication and active--TBCA on the first postmyocardial 24 hours.

MATERIAL AND METHODS

We studied 479 patients admitted to hospital not later than 6 hours since STEMI onset and either having SR (n = 49) or treated using active methods of coronary circulation restoration--prehospital thrombolysis (n = 127), thrombolysis after hospitalization (n = 127), primary TBCA (n = 60) and TBCA after initiation of TLT (n = 116). We made a more detailed analysis on the sample of 149 SR patients.

RESULTS

SR was diagnosed in 10.2% cases with STEMI and occurred much earlier than recovery of coronary circulation due to TLT and/or TBCA. Patients with SR developed Q-MI, right ventricular infarction, cardiac failure and atrioventricular block less frequently. They had the lowest peak activity of creatin phosphokinase and a higher left ventricular ejection fraction versus patients without SR (50.7 +/- 6.8 and 45.4 +/- 6.6%, respectively; p < 0.05). As shown by coronaroangiography, SR patients had no "no reflow" phenomenon (0% and 17%, respectively). Active policy of SR patients treatment had no significant advantages over conservative treatment.

CONCLUSION

Early SR had more favourable course of MI, less mass of the affected myocardium and better contractile function of the left ventricle. The conservative policy of STEMI treatment in the presence of SR is more effective than the active one if a due control over the patients' condition is provided.

[Heart rate and acute coronary syndrome: crosslink mechanisms and possibilities of drug intervention]

Studies in general population, in elderly people, and in groups of patients with arterial hypertension, myocardial infarction, stable coronary heart disease, diabetes mellitus, and after coronary bypass surgery have shown that elevated heart rate (HR) is prognostically unfavorable factor of cardiovascular and total mortality independent of other risk factors. Moreover, it has been shown that tachycardia to a certain extent correlates with severity and progression of atherosclerosis and can promote damage of integrity of atherosclerotic plaque. Plaque rupture plays main role in pathogenesis of acute coronary syndrome (ACS). Lowering of HR is one of therapeutic approaches to prevention of plaque rupture, i.e. to lowering of risk of ACS development. Mechanisms of interrelationships between HR and ACS and possibilities to influence HR with drugs in ACS are presented in this review.

[Use of a Soviet-made device for recording late ventricular potentials]

Late ventricular potentials (LVP) were detected with an ECG signal-averaging installation developed at the Institute of Radio Engineering and Electronics, USSR Academy of Sciences. A total of 103 patients were examined: 33 with sustained ventricular tachycardia (VT), 30 with unsustained VT and high-grade ventricular premature contraction, 20 with coronary heart disease, postinfarction cardiosclerosis without arrhythmias and 20 apparently healthy subjects (controls). LVPs are the most susceptible to sustained VT in the presence of postinfarction cardiosclerosis (77%), their specificity is lower (70%). LVPs are a low sensitive marker (35%) for sustained idiopathic VT. In unsustained VT and high-grade premature ventricular contraction, LVPs were recorded infrequently in 1 (3%) of the 30 patients.