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.

[ECG abnormalities in athletes as compare to healthy subjects]

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.