Israel Medical Association Journal

Background: Sudden death in athletes can occur during sport activities and is presumably related to ventricular arrhythmias.

Objectives: To investigate the long-term follow-up of athletes with ventricular arrhythmias during an exercise test.

Methods: From a database of 56,462 athletes we identified 192 athletes < 35 years old who had ventricular arrhythmias during an exercise test. Ninety athletes had ≥ 3 ventricular premature beats (VPB) (group A) and 102 athletes had ventricular couplets or non-sustained ventricular tachycardia (NSVT) during an exercise test (group B). A control group of 92 athletes without ventricular arrhythmias was randomly selected from the database (group C). Of the 192 athletes 39 returned for a repeat exercise test after a mean follow-up period of 70 ± 25 months and they constitute the study population.

Results: Twelve athletes from group A, 21 from group B and 6 from group C returned for a repeat exercise test. The athletes reached a significantly lower peak heart rate during their follow-up exercise test (P = 0.001). More athletes were engaged in competitive sports during their initial exercise test than in the follow-up test (P = 0.021). Most of the athletes who had VPB and/or ventricular couplets and/or NSVT during their initial exercise test had far fewer ventricular arrhythmias in the follow-up exercise test (P = 0.001).

Conclusions: Athletes engaged in competitive sports are more likely to develop ventricular arrhythmias during exercise. These arrhythmias subside over time when athletes are engaged in non-competitive sports. 

Background: Sudden death in athletes can occur during sport activities and is presumably related to ventricular arrhythmias. There are no guidelines concerning athletes who develop ventricular arrhythmias during an exercise test. It is unclear whether they should be allowed to continue with their competitive activity or not.

Objectives: To investigate the long-term follow-up of athletes with ventricular arrhythmias during an exercise test.

Methods: From a database of 56,462 athletes we identified 192 athletes, less than 35 years old, who had ventricular arrhythmias during an exercise test. Ninety athletes had ≥ 3 ventricular premature beats (group A) and 102 athletes had ventricular couplets or non-sustained ventricular tachycardia during an exercise test (group B). A control group of 92 athletes without ventricular arrhythmias was randomly selected from the database (group C).

Results: All athletes, except one who died from a dilated cardiomyopathy, were alive during a follow-up period of 70 ± 25 months. An abnormal echocardiogram was obtained in seven athletes from group A (10%), four from group B (5%), and one from group C (3%) (not significant). An abnormal echocardiogram was more likely to be present in competitive athletes (P = 0.001) and in female athletes (P = 0.01).

Conclusions: Our results showed that ventricular arrhythmias during exercise are more commonly associated with cardiovascular abnormalities in young competitive athletes and in female athletes. When present, they necessitate a thorough investigation and follow-up.
 

Background: Epidemiological data show significant associations of vitamin D deficiency and autoimmune diseases. Vitamin D may prevent autoimmunity by stimulating naturally occurring regulatory T cells.

Objectives: To elucidate whether vitamin D supplementation increases Tregs[1] frequency (%Tregs) of circulating CD4+ T cells.

Methods: We performed an uncontrolled vitamin D supplementation trial among 50 apparently healthy subjects including supplementation of 140,000 IU at baseline and after 4 weeks (visit 1). The final follow-up visit was performed 8 weeks after the baseline examination (visit 2). Blood was drawn at each study visit to determine 25-hydroxyvitamin D levels and %Tregs. Tregs were characterized as CD4+CD25++ T cells with expression of the transcription factor forkhead box P3 and low or absent expression of CD127.

Results: Forty-six study participants (65% females, mean age ± SD 31 ± 8 years) completed the trial. 25(OH)D[2] levels increased from 23.9 ± 12.9 ng/ml at baseline to 45.9 ± 14.0 ng/ml at visit 1 and 58.0 ± 15.1 ng/ml at visit 2. %Tregs at baseline were 4.8 ± 1.4. Compared to baseline levels we noticed a significant increase of %Tregs at study visit 1 (5.9 ± 1.7, P < 0.001) and 2 (5.6 ± 1.6, P < 0.001).

Conclusions: Vitamin D supplementation was associated with significantly increased %Tregs in apparently healthy individuals. This immunomodulatory effect of vitamin D might underlie the associations of vitamin D deficiency and autoimmune diseases. Hence, our finding provides a rationale for further studies to investigate vitamin D effects on autoimmunological processes.