Dayna A. Johnson

Background Sedentary behavior (SB) has been associated with cardiovascular disease risk, independent of physical activity (PA) and sleep. However, the effect of replacing SB with PA or sleep on atrial fibrillation (AF) risk remains unclear. Methods We studied 86,096 participants from the United Kingdom Biobank (UKB) and 5,777 from the United States (US) REasons for Geographic And Racial Differences in Stroke (REGARDS) prospective cohort studies who were free of AF at baseline and had valid accelerometry data. The two cohorts were included to evaluate the consistency of associations across distinct populations in the UK and the US, two regions with a high burden of AF. Daily time spent in light PA (LPA), moderate to vigorous PA (MVPA), and SB were derived from accelerometer recordings; sleep was accelerometer-derived in UKB and self-reported in REGARDS. Incident AF was identified using ICD-10 codes (I48.x) listed as either a primary diagnosis, secondary diagnosis, or cause of death through hospital and death registry data linkage in UKB and in a follow-up visit through electrocardiogram and self-reported medical history in REGARDS. Isotemporal substitution models were used to examine replacing 30 minutes of SB with LPA or MVPA in both cohorts and with sleep in UKB on the outcome of incident AF. Results Among the UKB participants [57% female, mean age 56.0 (SD 7.8) years, 98% White race], 4,035 AF cases were identified during a median of 7.9 years of follow-up. Replacing 30 minutes of SB with PA was associated with a slightly lower risk of AF in the minimally adjusted models but the associations were attenuated after full adjustment (LPA: HR 0.99, 95% CI 0.95-1.02; MVPA: HR 1.00, 95% CI 0.99-1.02). The REGARDS participants had an average age of 63 (SD 8.3) years, 55% female, 31% Black and 69% White adults, with 486 AF cases identified. Fully adjusted substitution of 30 minutes of SB with MVPA was associated with lower AF odds (OR 0.80, 95% CI 0.63-1.01), whereas LPA showed no association. In UKB, replacing SB with sleep was not associated with AF risk. The magnitude of the association of MVPA substitution with AF appeared stronger among REGARDS participants aged ≥65 years and those reporting <7 hours/day of sleep. Conclusion Replacing SB with moderate or higher intensity PA may decrease AF risk. In REGARDS, these substitutions appeared to benefit older individuals and those reporting shorter sleep duration. These findings highlight the potential benefit of reducing sedentarism to lower AF burden, warranting validation in future studies.

Background/Objectives: Sleep is critical for young adults, particularly those with type 1 diabetes (T1D), who face unique challenges in achieving recommended sleep and diabetes health targets. The purpose of this study guided by the theoretical framework of self-regulation theory is to explore how these individuals navigate self-regulatory processes in their sleep behaviors through mechanisms of self-monitoring, self-judgment, and self-evaluation. Methods: A qualitative descriptive design was implemented using semi-structured interviews with 34 young adults (ages 18–30) living with T1D. Data were collected through focused interviews, sleep diaries, actigraphy, and continuous glucose monitoring, followed by thematic analysis to identify sleep behavior self-regulation patterns. Results: Three primary themes were identified: (1) Sleep Behavior Self-Monitoring—highlighting participants’ awareness of their sleep habits and the diabetes-related impacts on these habits; (2) Sleep Behavior Self-Judgment—reflecting how personal and societal standards inform their evaluation of sleep health; (3) Sleep Behavior Self-Evaluation—showing emotional responses associated with sleep out-comes, where good sleep led to positive feelings and motivation, while poor sleep resulted in frustration. Conclusions: Understanding sleep behavior self-regulation among young adults with T1D is crucial for improving sleep health and diabetes management. Targeted interventions incorporating sleep education and self-regulatory strategies may enhance both perceived sleep quality and overall well-being in this population.

Background: In 2024, the Supreme Court ruled in the City of Grants Pass vs Johnson that local towns and municipalities may ban people from sleeping in public places, overturning a lower-court precedent that previously deemed this cruel and unusual punishment. Purpose: This position paper sought to identify effective interventions for addressing homelessness and emphasize the implications of legislature on sleep and public health outcomes. Methods: As this is a policy position paper, the opinions listed in this report have been informed by existing evidence. We provide policy recommendations for research-supported approaches addressing homelessness. Results: Successful interventions for homelessness included those that focused on providing support and increasing resources, such as the development of Safe Sleeping Zones in California, or providing individuals with housing subsidies, income assistance, or support in finding rentals. Conclusion: We provide the following policy recommendations for legislators: increased federal funding/incentives for unsheltered homelessness programs, a greater allocation of the federal budget attributed to supportive services, and increased legislation for homelessness prevention. We suggest a shift in focus on implementing more empowerment and supportive-based approaches as opposed to punitive approaches. Investing in homelessness prevention efforts has yielded long-term societal-level financial and economic benefits.

Background: Blood biomarkers can characterize the atrial substrate, helping to elucidate mechanisms of atrial fibrillation (AF) development. Understanding whether sedentary behavior affects AF-related biomarkers is key for future prevention strategies. Methods: We studied 252 participants in PREDIMED-Plus, a multicenter randomized trial in Spain for the primary prevention of cardiovascular disease. A wrist-worn accelerometer was used to measure physical activity (PA) in a week at baseline and at least once during follow-up at years 3 and 5. Blood samples were collected at each time point to measure selected cardiovascular biomarkers: propeptide of procollagen type I, high-sensitivity (hs) troponin T (hsTnT), hs C-reactive protein, 3-nitrotyrosine, and N-terminal propeptide of B-type natriuretic peptide (NT-proBNP). Sedentary time was assessed as inactive time (< 1.5 METs in waking time). Using isotemporal substitution, we analyzed the impact of replacing 30-min sedentary time per day with low-intensity PA (LPA, 1.5–3 METs), moderate to vigorous PA (MVPA, > 3 METs) and time in bed (time difference between going to bed and getting up) on log-transformed biomarkers cross-sectionally and longitudinally, using linear regression and mixed models. Results: At baseline, 252 eligible participants averaged 65 years of age (SD 4.9), and BMI 32.2 kg/m² (SD 3.3), and 40% were female. Cross-sectionally, replacing 30-min sedentary time with LPA, MVPA, or time in bed had no significant association with biomarkers. After 5 years, replacing baseline 30-min of sedentary time per day with LPA or MVPA was associated with lower hs-TnT concentrations compared to baseline (−4%, 95% CI - 8%, −1%; −2%, 95% CI −7%, 4%, respectively). Substituting 30-min sedentary time with LPA or MVPA showed nonsignificant reductions in NT-proBNP (−3%, 95% CI −11%, 5%; - 8%, 95% CI -20%, 5%, respectively), but not a consistent association with other biomarkers. Conclusion: In overweight/obese individuals, prolonged sedentary time, when compared to engaging in PA, was associated with unfavorable changes of hs-TnT over 5 years, but no significant impact on other AF-related biomarkers.