Effect of Exercise Repetitions on Arylesterase Activity of PON1 in Plasma of Average-Trained Men-The Dissociation between Activity and Concentration.

Exercise may increase the antioxidant capacity of plasma by stimulating antioxidant enzymes. The study aimed to measure the effect of three repetitions of acute exercise on arylesterase (ARE) activity of the paraoxonase 1 (PON1) enzyme. Eleven average-trained men (age 34.0 ± 5.2 years) completed three treadmill runs. ARE activity in plasma was evaluated spectrophotometrically and compared with PON1 concentration (PON1c), paraoxonase (PON) activity, and high-density lipoprotein cholesterol (HDL-C) at rest and after exercise. In all repetitions of the exercise, ARE activity remained stable, and ARE activity standardized for PON1c (ARE/PON1c) was lower post- than pre-exercise. The ARE/PON1c ratio changes returned to baseline levels during rest after each exercise session. Pre-exercise ARE activity correlated negatively with post-exercise C-reactive protein (CRP) (ρ = -0.35, p = 0.049), white blood cell count (WBC) (ρ = -0.35, p = 0.048), polymorphonuclear leukocytes (PMN) (ρ = -0.37, p = 0.037), and creatine kinase (CK) (ρ = -0.37, p = 0.036). ARE activity may be depleted under conditions of oxidative stress, as increases in PON1c during acute exercise did not result in parallel increases in ARE activity. No adaptation of the response of ARE activity to exercise was detected in subsequent exercise sessions. Individuals with lower pre-exercise ARE activity may develop a higher inflammatory response to strenuous exercise.

Interleukin-4 during post-exercise recovery negatively correlates with the production of phagocyte-generated oxidants.

Exhaustive run induced a biphasic oxidative response of circulating phagocytes in 16 amateur sportsmen. The first phase involved an increment just after exercise of enhanced whole blood chemiluminescence normalized per phagocyte count, whereas in the second phase a decrement from 1 h post-exercise and ongoing till 24 h. We tested whether plasma Interleukin IL-4, IL-8, IL-10 and Tumor Necrosis Factor α concentrations change in response to exhaustive run and whether there are associations between their levels and delta resting. Moreover, IL-8 and IL-10 significantly increased immediately post-exercise and after 1 h, but later normalized. Tumor necrosis factor α rose by 1.1-times only just after exercise. However, none of these cytokines showed any correlation with the investigated chemiluminescence. Exercise did not alter plasma concentrations of IL-4. However, pre-exercise IL-4 negatively correlated with measured luminescence just after exercise (ρ = -0.54, p < 0.05), and also tended to be negatively associated with decrements of the second phase at 1 h post-exercise ρ = -0.45, p = 0.08. It is suggested that plasma IL-4, by a negative association with blood phagocytes oxidants production, could be involved in the maintenance of proper balance between oxidants and anti-oxidants during strenuous exercise and post-exercise recovery.

Exhaustive Exercise Increases Spontaneous but Not fMLP-Induced Production of Reactive Oxygen Species by Circulating Phagocytes in Amateur Sportsmen.

Strenuous exercise alters the oxidative response of blood phagocytes to various agonists. However, little is known about spontaneous post exercise oxidant production by these cells. In this cross-over trial, we tested whether an exhaustive treadmill run at a speed corresponding to 70% of VO2max affects spontaneous and fMLP-provoked oxidant production by phagocytes in 18 amateur sportsmen. Blood was collected before, just after, and 1, 3, 5 and 24 h post exercise for determination of absolute and normalized per phagocyte count spontaneous (a-rLBCL, rLBCL) and fMLP-induced luminol-enhanced whole blood chemiluminescence (a-fMLP-LBCL, fMLP-LBCL). a-rLBCL and rLBCL increased by 2.5- and 1.5-times just after exercise (p < 0.05) and then returned to baseline or decreased by about 2-times at the remaining time-points, respectively. a-fMLP-LBCL increased 1.7- and 1.6-times just after and at 3 h post-exercise (p < 0.05), respectively, while fMLP-LBCL was suppressed by 1.5- to 2.3-times at 1, 3, 5 and 24 h post-exercise. No correlations were found between elevated post-exercise a-rLBCL, a-fMLP-LBCL and run distance to exhaustion. No changes of oxidants production were observed in the control arm (1 h resting instead of exercise). Exhaustive exercise decreased the blood phagocyte-specific oxidative response to fMLP while increasing transiently spontaneous oxidant generation, which could be a factor inducing secondary rise in antioxidant enzymes activity.

Repetitions of Strenuous Exercise Consistently Increase Paraoxonase 1 Concentration and Activity in Plasma of Average-Trained Men.

OBJECTIVES: Oxidative stress, induced by physical activity, may stimulate the expression, release, and activity of certain antioxidant enzymes. We investigated the effect of three repeated bouts of strenuous exercise on paraoxonase 1 concentration (PON1c) and paraoxonase activity (PON). METHODS: Eleven average-trained healthy men (age 34.0 ± 5.2 years) performed three strenuous exercise tests on a treadmill separated by 72 hours periods of resting. PON1c, PON, ferric-reducing activity of plasma (FRAP), lipid profile, C-reactive protein concentration (CRP), and lactate concentration were determined in plasma. RESULTS: Each exercise bout resulted in similar PON1c, PON, FRAP, and high-density lipoprotein concentration (HDL-C) increments, while PON/HDL-C ratio remained stable in all repetitions. Percentage increments at the bout of each exercise were higher for PON1c (by 64.82% at the first, by 92.9% at the second, and by 77.02% at the third exercise) than for PON (by 6.49% at the first, 10.06% at the second, and by 12.32% at the third exercise). Association was found between preexercise PON and PON1c (r = 0.56, p = 0.029), pre- (r = 0.87, p = 0.00003) and postexercise HDL-C (r = 0.6, p = 0.0002), preexercise PON and cardiovascular fitness level of participants measured as VO2max (r = 0.39, p = 0.026), and postexercise PON and lactate concentration (r = 0.44, p = 0.01). CONCLUSIONS: PON1c and PON increase during strenuous exercise, yet the effect of exercise on PON1 concentration is more pronounced. PON1 does not show tolerance to physical activity. The enzyme may provide short-term protection from oxidative stress in each exercise bout. PON may depend on exercise load. Cardiovascular fitness levels may be associated with PON1 activity.

Circulating cell free DNA response to exhaustive exercise in average trained men with type I diabetes mellitus.

It is believed that neutrophils extracellular traps (NETs) formation is responsible for the increase in cf DNA after exercise. Since T1DM is accompanied by enhanced NETs generation, we compared exercise-induced increase in cf DNA in 14 men with T1DM and 11 healthy controls and analyzed its association with exercise load. Subjects performed a treadmill run to exhaustion at speed corresponding to 70% of their personal VO2max. Blood was collected before and just after exercise for determination of plasma cf nuclear and mitochondrial DNA (cf n-DNA, cf mt-DNA) by real-time PCR, blood cell count and metabolic markers. Exercise resulted in the increase in median cf n-DNA from 3.9 ng/mL to 21.0 ng/mL in T1DM group and from 3.3 ng/mL to 28.9 ng/mL in controls. Median exercise-induced increment (∆) in cf n-DNA did not differ significantly in both groups (17.8 ng/mL vs. 22.1 ng/mL, p = 0.23), but this variable correlated with run distance (r = 0.66), Δ neutrophils (r = 0.86), Δ creatinine (r = 0.65) and Δ creatine kinase (r = 0.77) only in controls. Pre- and post-exercise cf mt-DNA were not significantly different within and between groups. These suggest low usefulness of Δ cf n-DNA as a marker of exercise intensity in T1DM men.

[ECG abnormalities in athletes as compare to healthy subjects]. / Nieprawidlowosci w EKG u sportowców w porównaniu z grupa kontrolna.

Physical exercise promotes structural heart adaptation and increased parasympathetic autonomous activity in athletes. Some reports indicate that sinus bradycardia can promote occurrence of arrhythmias in athletes. AIM: The aim of this study was to compare the 12-lead surface ECG findings and arrhythmias/conduction disturbances detected in ambulatory ECG monitoring (AECG) between amateur athletes and healthy subject and to investigate relationship between bradycardia and arrhythmias. MATERIALS AND METHODS: Studied population included 34 athletes (29M, 5F, av. age 29±8yrs) and a control group of 34 healthy volunteers (29M, 5F, av. age 30±8yrs). 12-lead surface ECG and 24-hour AECG were performed in order to evaluate heart rate and arrhythmia/conduction disturbances in two groups. RESULTS: The athletes group was characterized by lower heart rate (med.59 vs.70 bpm, p<0.001), longer PR interval (med. 174 vs. 150 msec, p=0.007) and longer QTcF interval (med. 403 vs. 395 msec, p=0.026), with no statistically difference in QRS duration (med. 99 vs. 102 msec, p=0.699). Voltage criteria of LVH were observed in 10/34 (29%) of athletes and in 1 (2.94%) healthy subject. Four athletes (12%) showed first degree AV block. Similarly to ECG findings, AECG showed lower HR values (med. 66 vs.74 bpm, p<0.001) in athletes than in healthy subjects. Sinus bradycardia (<60bpm) was observed in 26% of athletes and 0% of controls (p=0.042). Ventricular arrhythmia was observed in 62% of athletes and 50% of healthy controls (p=0.464). No difference in occurrence of APBs was observed between studied groups (88% vs. 91%). Differences between occurrence of arrhythmias in athletes with lower HR (<60bpm) compared to those with higher did not reach statistical significance (VPBs: 6/9 vs. 15/25, p = 0.963; APBs: 9/9 vs 21/29, p = 0.5). CONCLUSIONS: Bradycardia does not promote ventricular neither atrial arrhythmias in athletes.

Physical workload and glycemia changes during football matches in adolescents with type 1 diabetes can be comparable.

AIMS: To analyze physical performance and diabetes-related outcomes in adolescents with type 1 diabetes (T1DM) during two semi-competitive football matches utilising precise physical activity monitoring. METHODS: The study was conducted during an annual summer camp for adolescents with T1DM. After physical examination and glycated hemoglobin measurement, 16 adolescent players completed Cooper's 12-min running test and, in the following days, took part in two football matches while wearing heart rate (HR) monitors coupled with global positioning system (GPS) tracking. RESULTS: Both matches were comparable in terms of covered distances, number of sprints, achieved velocities and heart rate responses. During both games, capillary blood lactate increased significantly (Match 1: 1.75 ± 0.16-6.13 ± 1.73 mmol/l; Match 2: 1.77 ± 0.18-3.91 ± 0.63 mmol/l, p = 0.004). No significant differences in blood glucose were observed between the matches (p = 0.83) or over each match (p = 0.78). Clinically significant hypoglycemia (< 54 mg/dl) occurred in two children during the first match. None of the players experienced severe hypoglycemia. Despite similar workloads, players consumed significantly less carbohydrates during Match 2 [median difference: - 20 g (25-75%: - 40 to 0), p = 0.006]. CONCLUSIONS: HR monitoring and GPS-based tracking can effectively parameterize physical activity during a football match. In T1DM patients, exercise workload and glycemic changes during similar matches are comparable, which provides an opportunity to develop individual recommendations for players with T1DM.

Assessment of Exercise Capacity in Children with Type 1 Diabetes in the Cooper Running Test.

Regular physical activity increases lifespan for those with type 1 diabetes. However, disease-related barriers may deter children from exercise and affect their fitness. This study examined the safety of the Cooper test concerning diabetes-related acute complications in children with type 1 diabetes and their fitness. Blood glucose was recorded before and 0, 30, 60 min after the test. The covered distances were transformed to z-scores based on the national charts. Body mass index, body fat percentage and glycated hemoglobin were measured. The run was completed by 80 individuals (45% boys, age 13.6±2.1 years; diabetes duration 6.3±3.5 years). During the follow-up 11 children reached glucose alert values (3-3.9 mmol/L), 3 presented clinically significant hypoglycemia (<3 mmol/L), none experienced severe hypoglycemia. The covered distance was 1914±298 m, not significantly different from the reference population (z-score -0.12±0.71 vs 0, p=0.12). The study participants were more overweight than general pediatric population in terms of body mass index (z-score 0.48±0.94 vs 0, p<0.001) and body fat percentage (z-score: 0.37±0.85 vs 0, p<0.001). In conclusion, the Cooper test can be safely used in children with diabetes to assess their physical capacity. Youth with type 1 diabetes present fitness similar to healthy children but exhibit increased body mass index and adiposity.