Physical activity may compensate for prolonged TV time regarding pulse rate-a cross-sectional study

Associations of Sedentary Time with Heart Rate and Heart Rate Variability in Adults: A Systematic Review and Meta-Analysis of Observational Studies

PURPOSE

To evaluate if sedentary time (ST) is associated with heart rate (HR) and variability (HRV) in adults.

METHODS

We systematically searched PubMed and Google Scholar through June 2020. Inclusion criteria were observational design, humans, adults, English language, ST as the exposure, resting HR/HRV as the outcome, and (meta-analysis only) availability of the quantitative association with variability. After qualitative synthesis, meta-analysis used inverse variance heterogeneity models to estimate pooled associations.

RESULTS

Thirteen and eight articles met the criteria for the systematic review and meta-analysis, respectively. All studies were cross-sectional and few used gold standard ST or HRV assessment methodology. The qualitative synthesis suggested no associations between ST and HR/HRV. The meta-analysis found a significant association between ST and HR (β = 0.24 bpm per hour ST; CI: 0.10, 0.37) that was stronger in males (β = 0.36 bpm per hour ST; CI: 0.19, 0.53). Pooled associations between ST and HRV indices were non-significant (p > 0.05). Substantial heterogeneity was detected.

CONCLUSIONS

The limited available evidence suggests an unfavorable but not clinically meaningful association between ST and HR, but no association with HRV. Future longitudinal studies assessing ST with thigh-based monitoring and HRV with electrocardiogram are needed.

Academic Stress and Physical Activity in Adolescents

The issue of work-related mental health needs to be addressed at the school level. The aim of this study was to explore the associations between academic stress (AS) of adolescent boys and girls and their physical activity (PA) during recesses and after school and to propose measures to promote the adoption of lifelong healthy working habits. Adolescents from 16 schools in the Czech Republic and 6 schools in Poland participated in the study (187 boys and 339 girls). Monitoring of PA and cognitive stress was conducted during one school day. We used ActiTrainer accelerometers to monitor PA and physical inactivity. Data on time of PA and self-reported AS in school lessons were collected using recording sheets. We split the participants into two groups: those without a self-reported stressor and those who indicated one or more stressors. Differences in overall PA during recesses, as well as after-school PA, between boys with and without AS were not statistically significant for any PA characteristics. We observed similar results for girls. Repeated measures ANOVA confirmed that differences in PA (steps/hour) during recesses following particular lessons between participants with and without AS were not statistically significant in boys or girls (F (4,1612) = 1.83, p=0.121 , η p 2=0.005). It is noteworthy that girls with AS were statistically significantly more likely to meet the 6000 steps after school time recommendation (39%) than girls without AS (18%; p < 0.001). The study did not confirm the assumption that adolescents reporting AS have less PA during recesses or even after school than adolescents without AS. However, the overall low PA of adolescents during recesses and after school highlights the need to compensate for AS by adequate PA. This is especially true for adolescents with recurrent AS in several consecutive lessons.

Physical activity is associated with a large number of cardiovascular-specific proteins: Cross-sectional analyses in two independent cohorts

AIMS

We aimed to discover and replicate associations between leisure-time physical activity and cardiovascular candidate plasma protein biomarkers and to examine whether the associations were independent of body fat.

METHODS

We used cross-sectional data from two population-based cohorts, the EpiHealth (discovery cohort; n = 2239) and the Swedish Mammography Cohort - Clinical (SMCC; replication cohort; n = 4320). Physical activity during leisure time was assessed using questionnaires, and plasma concentrations of 184 proteins were assayed using the Olink Proseek Multiplex Cardiovascular 2 and 3 kits. We applied adjusted linear regression models using the False Discovery Rate to control for multiple testing in discovery.

RESULTS

In EpiHealth, physical activity was associated with 75 cardiovascular plasma biomarkers, of which 28 associations were verified (replicated) in SMCC. Findings include seven novel associations in human: paraoxonase 3, cystatin B, cathepsin Z, alpha-L-iduronidase, prostasin, growth differentiation factor 2 and tumour necrosis factor alpha receptor superfamily member 11A. Estimates for associations were similar across tertiles of body fat and physical activity was associated with four biomarkers independent of body fat percentage: paraoxonase 3, cystatin B, fatty acid-binding protein 4 and interleukin-1 receptor antagonist.

CONCLUSION

Leisure-time physical activity was associated with 28 cardiovascular-specific proteins; four associations were independent of body fat. Biomarkers in novel associations are involved in several atherosclerotic processes including regulation of low-density lipoprotein oxidation, protein degradation and immune cell adhesion and migration. Further research into these pathways may yield new insights into how physical activity affects cardiovascular health.