Atrial fibrillation and cycling: six year follow-up of the Taupo bicycle study

A Novel mHealth Monitoring System during Cycling in Elite Athletes

Background: Cycling is a very demanding physical activity that may create various health disorders during an athlete’s career. Recently, smart mobile and wearable technologies have been used to monitor physiological responses and possible disturbances during physical activity. Thus, the application of mHealth methods in sports poses a challenge today. This study used a novel mobile-Health method to monitor athletes’ physiological responses and to detect health disorders early during cycling in elite athletes. Methods: Sixteen high-level cyclists participated in this study, which included a series of measurements in the laboratory; health and performance assessments; and then application in the field of mHealth monitoring in two training seasons, at the beginning of their training period and in the race season. A field monitoring test took place during 30 min of uphill cycling with the participant’s heart rate at the ventilatory threshold. During monitoring periods, heart rate, oxygen saturation, respiratory rate, and electrocardiogram were monitored via the mHealth system. Moreover, the SpO₂ was estimated continuously, and the symptoms during effort were reported. Results: A significant correlation was found between the symptoms reported by the athletes in the two field tests and the findings recorded with the application of the mHealth monitoring method. However, from the pre-participation screening in the laboratory and from the spiroergometric tests, no abnormal findings were detected that were to blame for the appearance of the symptoms. Conclusions: The application of mHealth monitoring during competitive cycling is a very useful method for the early recording of cardiac and other health disorders of athletes, whose untimely evaluation could lead to unforeseen events.

Atrial Fibrillation (AF) in Endurance Athletes: a Complicated Affair

PURPOSE OF REVIEW

A complex relationship exists between exercise and atrial fibrillation (AF). Moderate exercise reduces AF risk whereas intense strenuous exercise has been shown to increase AF burden. It remains unclear at which point exercise may become detrimental. Overall, endurance athletes remain at lower cardiovascular risk and experience fewer strokes. The questions that arise therefore are whether AF is an acceptable byproduct of strenuous exercise, whether athletes who experience AF should be told to reduce exercise volume and how should they be managed. This review aims to critically review the literature and advise on how best to manage athletes with AF.

RECENT FINDINGS

Emerging evidence suggests that female athletes may exhibit lower risk of AF, but data is limited in female endurance athletes. AF is more prevalent in endurance athletes, particularly men and those who competed at a young age. Data is lacking in females and ethnic minorities. Current evidence suggests that treatment options for AF in athletes are similar to those used in the general population; however, medical therapy may be poorly tolerated. Catheter ablation is effective and can allow return to full competition.

Physical activity volume in relation to risk of atrial fibrillation. A non-linear meta-regression analysis

Background

Light physical activity is known to reduce atrial fibrillation risk, whereas moderate to vigorous physical activity may result in an increased risk. However, the question of what volume of physical activity can be considered beneficial remains poorly understood. The scope of the present work was to examine the relation between physical activity volume and atrial fibrillation risk.

Design

A comprehensive systematic review was performed following the PRISMA guidelines.

Methods

A non-linear meta-regression considering the amount of energy spent in physical activity was carried out. The first derivative of the non-linear relation between physical activity and atrial fibrillation risk was evaluated to determine the volume of physical activity that carried the minimum atrial fibrillation risk.

Results

The dose–response analysis of the relation between physical activity and atrial fibrillation risk showed that physical activity at volumes of 5–20 metabolic equivalents per week (MET-h/week) was associated with significant reduction in atrial fibrillation risk (relative risk for 19 MET-h/week = 0.92 (0.87, 0.98). By comparison, physical activity volumes exceeding 20 MET-h/week were unrelated to atrial fibrillation risk (relative risk for 21 MET-h/week = 0.95 (0.88, 1.02).

Conclusion

These data show a J-shaped relation between physical activity volume and atrial fibrillation risk. Physical activity at volumes of up to 20 MET-h/week is associated with reduced atrial fibrillation risk, whereas volumes exceeding 20 MET-h/week show no relation with risk.

The ambiguity of physical activity, exercise and atrial fibrillation

Although commonly associated with cardiovascular disease or other medical conditions, atrial fibrillation may also occur in individuals without any known underlying conditions. This manifestation of atrial fibrillation has been linked to extensive and long-term exercise, as prolonged endurance exercise has shown to increase prevalence and risk of atrial fibrillation. In contrast, more modest physical activity is associated with a decreased risk of atrial fibrillation, and current research indicates a J-shaped association between atrial fibrillation and the broad range of physical activity and exercise. This has led to the hypothesis that the mechanisms underlying an increased risk of atrial fibrillation with intensive exercise are different from those underlying a reduced risk with moderate physical activity, possibly linked to distinctive characteristics of the population under study. High volumes of exercise over many years performed by lean, healthy endurance trained athletes may lead to cardiac (patho)physiological alterations involving the autonomic nervous system and remodelling of the heart. The mechanisms underlying a reduced risk of atrial fibrillation with light and moderate physical activity may involve a distinctive pathway, as physical activity can potentially reduce the risk of atrial fibrillation through favourable effects on cardiovascular risk factors.

HIV sero disclosure among men who have sex with men and transgender women on HIV pre-exposure prophylaxis

HIV pre-exposure prophyalxis (PrEP) might lead individuals to view serodisclosure as unnecessary. We examined the prevalence of non-disclosure and lack of knowledge of partner status in a global cohort of men who have sex with men (MSM) and transgender women (TW) enrolled in the iPrEx Open Label Extension (OLE). We calculated prevalence ratios by fitting a logistic model and estimating predicted probabilities using marginal standardization. Prevalence of non-disclosure and lack of knowledge of partner status were highest in Thailand (73% and 74%, respectively) and lowest in the USA (23% and 37%, respectively). In adjusted analyses, PrEP use was not significantly associated with non-disclosure or lack of knowledge of partner status (p-values>0.05). We found that relationship characteristics were significantly associated with both outcomes. Non-disclosure was higher among casual (adjusted prevalence ratio [aPR] 1.54, [95% confidence interval 1.24-1.84]) and transactional sex partners (aPR 2.03, [1.44-2.62]), and among partners whom participants have known only minutes or hours before their first sexual encounter (aPR 1.62, [1.33-1.92]). Similarly, participants were less likely to know the HIV status of casual partners (aPR 1.50, [1.30-1.71]), transactional sex partners (aPR 1.62, [1.30-1.95]), and those they have known for only days or weeks (aPR 1.13, [0.99-1.27]) or minutes or hours (aPR 1.27, [1.11-1.42]). Our findings underscore the role of dyadic factors in influencing serodisclosure. Comprehensive risk reduction counseling provided in conjunction with PrEP that address relationship characteristics are needed to help patients navigate discussions around HIV status.