MOTS-c Serum Concentration Positively Correlates with Lower-Body Muscle Strength and Is Not Related to Maximal Oxygen Uptake-A Preliminary Study.

The mitochondrial open reading frame of 12S rRNA-c (MOTS-c) is a mitochondrial-derived peptide that regulates the nuclear genome during stressful conditions such as hypoxia, which is typical of exercise and training. We aim to mainly investigate the relationship between serum MOTS-c concentration and muscle strength parameters measured during the countermovement jump test with oxygen consumption (VO2) measured during the cardiopulmonary exercise test to exhaustion. Physically active healthy volunteers (17 male, three female, median age 30 years), not involved in any regular exercise program or participating in any sports competitions, performed five consecutive countermovement jump tests and cardiopulmonary exercise tests until maximal exhaustion and underwent a body composition assessment by means of bioelectrical impedance analysis, and had serum MOTS-c concentration measured at rest. Serum MOTS-c concentration was positively correlated with the average power and average and maximal force of the jumps, both overall muscle mass and leg muscle mass, but not with body fat percentage. There was no correlation with peak VO2. A higher serum MOTS-c concentration is associated with greater muscle mass, force, and power generated during jumping in healthy individuals but not exercise capacity reflected by peak VO2. More studies are needed to better understand the physiological and clinical values of these findings and why MOTS-c is better associated with measures of muscle strength and not endurance in physically active people.

Effect of COVID-19 on Blood Pressure Profile and Oxygen Pulse during and after the Cardiopulmonary Exercise Test in Healthy Adults.

Several reports have shown the impact of COVID-19 history on exercise capacity. This study compared the blood pressure (BP) response and oxygen pulse (O2 pulse) characteristics in normotensive patients with and without a history of COVID-19 during the cardiopulmonary exercise test (CPET) and post-exercise recovery. This cross-sectional study involved 130 healthy Caucasian adult volunteers (71 participants with a history of COVID-19). All patients underwent the CPET with blood pressure measurements during exercise and post-exercise recovery. The post-COVID group had significantly higher systolic, diastolic, and mean blood pressure after 9 min of recovery and achieved a significantly lower max O2 pulse (2.02 mL/beat on average) than the controls. It should be noted that the COVID group tended to have higher blood pressure values in all steps, with no differences in heart rate, pulse pressure, and saturation at any step. The COVID-19 outbreak was associated with a higher blood pressure response, significantly, in post-exercise recovery, a lower maximum O2 pulse, and a lower maximum load achievement. Future studies are needed to determine if these abnormalities during the CPET and the blood pressure variation have prognostic value.

ATPase Inhibitory Factor 1-A Novel Marker of Cellular Fitness and Exercise Capacity?

ATPase inhibitory factor 1 is a myokine inhibiting the hydrolytic activity of mitochondrial adenosine triphosphate synthase and ecto-F1-ATPase on the surface of many cells. IF1 affects ATP metabolism in mitochondria and the extracellular space and upregulates glucose uptake in myocytes; these processes are essential in physical activity. It is unknown whether the IF1 serum concentration is associated with exercise capacity. This study explored the association between resting IF1 serum concentration and exercise capacity indices in healthy people. IF1 serum concentration was measured in samples collected at rest in 97 healthy amateur cyclists. Exercise capacity was assessed on a bike ergometer at the successive stages of the progressive cardiopulmonary exercise test (CPET). IF1 serum concentration was negatively and significantly correlated with oxygen consumption, oxygen pulse, and load at various CPET stages. A better exercise capacity was associated with lower circulating IF1. IF1 may reflect better cellular/mitochondrial energetic fitness, but there is uncertainty regarding how IF1 is released into the intravascular space. We speculate that lower IF1 concentration may reflect a better cellular/mitochondrial integrity, as this protein is bound more strongly with ATPases in mitochondria and cellular surfaces in people with higher exercise capacity.

A Human Model of the Effects of an Instant Sheer Weight Loss on Cardiopulmonary Parameters during a Treadmill Run.

Exercise tolerance is limited in obesity and improves after weight reduction; therefore, we mutually compared the relative changes in exercise capacity variables during cardiopulmonary exercise tests (CPET) in a 12 kg sheer weight reduction model. Twenty healthy male runners underwent two CPETs: CPET1 with the actual body weight, which determined the anaerobic threshold (AT) and respiratory compensation point (RCP); and CPET2 during which the participants wore a +12 kg vest and ran at the AT speed set during the CPET1. Running after body weight reduction shifted the CPET parameters from the high-mixed aerobic-anaerobic (RCP) to the aerobic zone (AT), but these relative changes were not mutually similar. The most beneficial changes were found for breathing mechanics parameters (range 12-28%), followed by cardiovascular function (6-7%), gas exchange (5-6%), and the smallest for the respiratory exchange ratio (5%) representing the energy metabolism during exercise. There was no correlation between the extent of the relative body weight change (median value ~15%) and the changes in CPET parameters. Weight reduction improves exercise capacity and tolerance. However, the observed relative changes are not related to the magnitude of the body change nor comparable between various parameters characterizing the pulmonary and cardiovascular systems and energy metabolism.

IgG4 as a Biomarker in Graves' Orbitopathy.

Immunoglobulin G4-related disease (IgG4-RD) is a chronic inflammatory disorder associated with fibrosis and abundant tissue lymphoplasmacytic infiltrations. It typically affects the pancreas, the salivary glands, and the retroperitoneal space. However, it might also involve multiple other organs, including the orbit and the thyroid. Recent studies have suggested that IgG4 plays a role in the pathophysiology of autoimmune thyroid diseases. This ultimately led to the establishment of new clinical entities called IgG4-related thyroid disease and thyroid disease with an elevation of IgG4. The aim of this paper is to describe the pathophysiological, histopathological, and clinical features of Graves' Disease (GD) and Graves' Orbitopathy (GO) with elevated IgG4 levels. Multiple studies have demonstrated higher IgG4 serum concentrations in GD patients than in healthy euthyroid controls. Depending on the studied population, elevated serum IgG4 levels occur in 6.4-23% (average: 10.3%) of all patients with GD, 8.3-37.5% (average: 17.6%) of patients with GO, and 0-9.8% (average: 5.4%) of patients with GD without GO, while GO patients comprise 37.5-100% (average: 65.8%) of all GD patients with elevated IgG4 levels. Characteristic features of GD with elevated IgG4 levels include lower echogenicity of the thyroid gland on ultrasound examination, peripheral blood eosinophilia, higher prevalence of orbitopathy, and better response to antithyroid drugs with a tendency to develop hypothyroidism when compared to patients with GD and normal levels of IgG4. Typical signs of GO accompanied by increased concentration of IgG4 include younger age at diagnosis, and more severe course of the disease with a higher Clinical Activity Score (CAS).. We strongly recommend considering the diagnosis of GO with elevated IgG4 in patients with an established diagnosis of GD, elevated serum IgG4 levels, and clinical features of ophthalmic disease overlapping with those of IgG4-related orbital disease.

Effect of sleep duration on blood pressure in women over 55 years of age - Poznan Cohort study.

INTRODUCTION: Hypertension is considered to be the most common pathology of the circulatory system and the most common cause of death or cardiovascular diseases' development. There are many commonly known risk factors of this condition, such as overweight, obesity, a high-fat diet, family history of ischemic heart disease, lipid disorders, and atherosclerosis. In order to reduce the effect of high blood pressure, patients should modify their lifestyle, including sleeping patterns. We wanted to investigate if, in a group of women over 55 years of age compared to the general population from Poznan cohort, sleep duration is related to hypertension. MATERIALS AND METHODS: All subjects were divided into three research groups depending on the time of sleep. The first group included people who have been sleeping less than 6 hours a day. The second group included people who have been sleeping from 6 to 9 hours a day. The third group was characterized by people with sleep time over 9 hours a day. Due to their age, participants were divided into two groups, below and over 55 years of age. RESULTS: There is a weak positive correlation between long sleep duration (>9h) and a higher prevalence of unregulated blood pressure (r = 0.3, p = 0.017) in the group of women over 55 years of age. CONCLUSION: Unregulated increased blood pressure may occur more frequently in postmenopausal women whose sleep duration exceeds 9 hours a day.

Effect of Various Exercise Regimens on Selected Exercise-Induced Cytokines in Healthy People.

Different forms of physical activity-endurance, resistance or dynamic power-stimulate cytokine release from various tissues to the bloodstream. Receptors for exercise-induced cytokines are present in muscle tissue, adipose tissue, liver, brain, bones, cardiovascular system, immune system, pancreas, and skin. They have autocrine, paracrine and endocrine activities. Many of them regulate the myocyte growth and differentiation necessary for muscle hypertrophy and myogenesis. They also modify energy homeostasis, lipid, carbohydrate, and protein metabolism, regulate inflammation and exchange information (crosstalk) between remote organs. So far, interleukin 6 and irisin have been the best studied exercise-induced cytokines. However, many more can be grouped into myokines, hepatokines and adipomyokines. This review focuses on the less known exercise-induced cytokines such as myostatin, follistatin, decorin, brain-derived neurotrophic factor, fibroblast growth factor 21 and interleukin 15, and their relation to various forms of exercise, i.e., acute vs. chronic, regular training in healthy people.

Titin and dystrophin serum concentration changes in patients affected by thyroid disorders.

INTRODUCTION: It is well established that thyroid hormones significantly affect skeletal muscle function, causing symptoms like myalgia and muscle weakness. Hypothyroid patients present increased levels of creatine kinase (CK), indicating muscle destruction. Lately, we proposed new serum markers of muscle disturbances in thyroid disorders: titin (TTN) and dystrophin (DMD). The aim of this study is to determine the association between thyroid status, muscle metabolism, and serum levels of TTN and DMD in patients affected by hypoand hyperthyroidism, before and after the treatment. MATERIAL AND METHODS: In the study 56 subjects were enrolled. The studied group consisted of 16 patients with newly diagnosed overt hypothyroidism and 20 patients with hyperthyroidism. Twenty healthy controls were also included in the study. Body composition, thyroid hormones, and biochemical markers of muscle deterioration levels were evaluated before and after restoration of euthyroidism. RESULTS: Dystrophin and TTN levels were noticeably lower in the hypothyroid group and hyperthyroid group in comparison with controls, at the border of statistical significance. Along with the thyroid hormones and CK normalisation, DMD levels increased in the hypothyroid group, with no significant lowering of TTN levels. However, TTN concentrations and the fT3/fT4 ratio became significantly lower than in controls. Hyperthyroid patients experienced no significant changes in TTN and DMD. CONCLUSIONS: The presented data indicate that TTN and DMD are potential new markers of musculoskeletal deterioration in thyroid disorders. In addition, the shift in TTN and DMD serum concentrations after the treatment of hypothyroidism accompanied by decreased fT3/fT4 ratio suggest the influence of the chosen therapeutic approach on muscle metabolism.

Arterial Stiffness Parameters Correlate with Estimated Cardiovascular Risk in Humans: A Clinical Study.

Arterial stiffness is said to be a novel predictor of cardiovascular events. This study investigated the correlation between arterial stiffness parameters and the estimated cardiovascular disease risk (RISK) in a Polish cohort of patients divided by age, sex, and body-mass index (BMI). The cross-sectional study enrolled 295 patients who met the inclusion criteria. Subjects were divided into three age groups, four weight groups, and by gender. The stiffness of the vessels was assessed by the measurement of the stiffness index (SI) and reflection index (RI). An individual 10-year RISK was calculated for each patient using the Heart Risk Calculator algorithm by the American Heart Association. A correlation between the SI and estimated RISK was observed (rS 0.42, p < 0.05). The strongest relationship was presented for women, the age group 40-54, and individuals with normal weight. The correlation between RI and calculated RISK was observed (rS 0.19, p < 0.05), the highest correlation was noticed for people aged 40-54 and obese. In conclusion, both SI and RI are correlated with estimated cardiovascular risk, however SI seems to be more useful than RI to predict the individual risk of future cardiovascular events. Both of these can be measured using non-invasive techniques, which demonstrates their potential utility in clinical practice.