Several studies investigated the role of physical activity in atrial fibrillation (AF), but the results remain controversial. We aimed to estimate the association between physical activity and incident AF, as well as to determine whether a sex difference existed. We systematically retrieved relevant studies from Cochrane Library, PubMed, and ScienceDirect through December 1, 2015. Data were abstracted from eligible studies and effect estimates pooled using a random-effects model. Thirteen prospective studies fulfilled inclusion criteria. For primary analysis, neither total physical activity exposure (relative risk [RR]: 0.98, 95% confidence interval [CI]: 0.90-1.06, P = 0.62) nor intensive physical activity (RR: 1.07, 95% CI: 0.93-1.25, P = 0.41) was associated with a significant increased risk of AF. In the country-stratified analysis, the pooled results were not significantly changed. However, in the sex-stratified analysis, total physical activity exposure was associated with an increased risk of AF in men (RR: 1.18, 95% CI: 1.02-1.37), especially at age <50 years (RR: 1.58, 95% CI: 1.28-1.95), with a significantly reduced risk of AF in women (RR: 0.92, 95% CI: 0.87-0.97). Additionally, male individuals with intensive physical activity had a slightly higher (although statistically nonsignificant) risk of developing AF (RR: 1.12, 95% CI: 0.99-1.28), but there was a significantly reduced risk of incident AF in women (RR: 0.92, 95% CI: 0.86-0.98). Published literature supports a sex difference in the association between physical activity and incident AF. Increasing physical activity is probably associated with an increased risk of AF in men and a decreased risk in women.

Objective:Studies have reported inconsistent results on the associations between lipids and insulin resistance (IR) and asthma. The purpose of this study was to examine the associations between abnormal serum lipid levels and homeostatic model assessment-IR (HOMA-IR) and the presence of current asthma in children and adolescents.Methods:The United States National Health and Nutrition Examination Survey database from 1999 to 2012 was randomly searched for children (aged 3-11 years) and adolescents (aged 12-19 years) with and without asthma and with complete demographic and clinical data of interest. Logistic regression analyses were performed to examine associations between abnormal serum lipids, glucose and HOMA-IR and the current presence of asthma.Results:The data of 11,662 children (3 to 11 years of age) and 12,179 adolescents (12 to 19 years of age) were included in the analysis. The study group included 3,703 participants with asthma and 20,138 participants without asthma. The prevalence of self-reported current asthma was higher among participants aged between 3-11 years (52.9%) than among those aged between 12-19 years (50.7%). Multivariate analyses, after adjusting for sex, race, income-to-poverty ratio, low birth weight, prenatal maternal smoking, tobacco exposure, C-reactive protein level and body mass index Z-score, revealed no associations between elevated fasting plasma glucose, reduced high-density lipoprotein cholesterol, elevated low-density lipoprotein cholesterol, total cholesterol, triglycerides and HOMA-IR and the presence of current asthma in children or adolescents.Conclusion:In this cross-sectional study, no association was found between abnormal serum lipids or HOMA-IR and the presence of current asthma in children or adolescents.