Sleep Architecture, Obstructive Sleep Apnea, and Cognitive Function in Adults.

Importance: Good sleep is essential for health, yet associations between sleep and dementia risk remain incompletely understood. The Sleep and Dementia Consortium was established to study associations between polysomnography (PSG)-derived sleep and the risk of dementia and related cognitive and brain magnetic resonance imaging endophenotypes. Objective: To investigate association of sleep architecture and obstructive sleep apnea (OSA) with cognitive function in the Sleep and Dementia Consortium. Design, Setting, and Participants: The Sleep and Dementia Consortium curated data from 5 population-based cohorts across the US with methodologically consistent, overnight, home-based type II PSG and neuropsychological assessments over 5 years of follow-up: the Atherosclerosis Risk in Communities study, Cardiovascular Health Study, Framingham Heart Study (FHS), Osteoporotic Fractures in Men Study, and Study of Osteoporotic Fractures. Sleep metrics were harmonized centrally and then distributed to participating cohorts for cohort-specific analysis using linear regression; study-level estimates were pooled in random effects meta-analyses. Results were adjusted for demographic variables, the time between PSG and neuropsychological assessment (0-5 years), body mass index, antidepressant use, and sedative use. There were 5946 participants included in the pooled analyses without stroke or dementia. Data were analyzed from March 2020 to June 2023. Exposures: Measures of sleep architecture and OSA derived from in-home PSG. Main Outcomes and Measures: The main outcomes were global cognitive composite z scores derived from principal component analysis, with cognitive domains investigated as secondary outcomes. Higher scores indicated better performance. Results: Across cohorts, 5946 adults (1875 females [31.5%]; mean age range, 58-89 years) were included. The median (IQR) wake after sleep onset time ranged from 44 (27-73) to 101 (66-147) minutes, and the prevalence of moderate to severe OSA ranged from 16.9% to 28.9%. Across cohorts, higher sleep maintenance efficiency (pooled ß per 1% increase, 0.08; 95% CI, 0.03 to 0.14; P < .01) and lower wake after sleep onset (pooled ß per 1-min increase, -0.07; 95% CI, -0.13 to -0.01 per 1-min increase; P = .02) were associated with better global cognition. Mild to severe OSA (apnea-hypopnea index [AHI] ≥5) was associated with poorer global cognition (pooled ß, -0.06; 95% CI, -0.11 to -0.01; P = .01) vs AHI less than 5; comparable results were found for moderate to severe OSA (pooled ß, -0.06; 95% CI, -0.11 to -0.01; P = .02) vs AHI less than 5. Differences in sleep stages were not associated with cognition. Conclusions and Relevance: This study found that better sleep consolidation and the absence of OSA were associated with better global cognition over 5 years of follow-up. These findings suggest that the role of interventions to improve sleep for maintaining cognitive function requires investigation.

The relationship of daily physical activity and sleep in adults: variations by age, sex, and race.

Prior work suggests physical activity (PA) is related to quantity and quality of sleep. Questions remain regarding directionality, and whether relationships vary by age, sex, and race. We examined daily bidirectional associations between PA and sleep over one week. Participants were 427 adults from the MIDUS Biomarker study, with a mean age of 54.21 ± 11.67 (61% female, 30% non-white). PA (total activity) and sleep (total sleep time; TST and waking after sleep onset; WASO) were measured with an ActiWatch 64. Multilevel mixed-effects models showed differences in the relationships between PA and sleep by age, race, and sex. Following a day with increased PA, younger and nonwhite participants had significantly shorter TST. Days with higher PA were also associated with less WASO for younger participants. Bidirectional effects also emerged; following a night with shorter TST, men, not women, engaged in less next-day PA. Like other studies of daily PA and sleep, effect sizes were small. Future studies should assess potential mechanisms that could explain these demographic differences.

Achieving and sustaining behavior change for older adults: A Research Centers Collaborative Network workshop report.

Modifying unhealthy behaviors and/or environments may improve or maintain an older adult's health. However, achieving and sustaining behavior change is challenging and depends upon clinical, social, psychological, and political domains. In an effort to highlight the multidisciplinary nature of behavior change, the NIA Research Centers Collaborative Network (RCCN) held a two-day workshop, Achieving and sustaining behavior change for older adults. The workshop was informed by the socioecological model and designed to initiate dialogue around individual, community, and systems-level determinants of behavior change. This paper summarizes key topics presented during the workshop, discusses opportunities for future research, education, and training, and recommends how each of the six NIA research centers may pursue work in behavior change for older adults.

Walking and Daily Affect Among Sedentary Older Adults Measured Using the StepMATE App: Pilot Randomized Controlled Trial.

BACKGROUND: Although fitness technology can track and encourage increases in physical activity, few smartphone apps are based on behavior change theories. Apps that do include behavioral components tend to be costly and often do not include strategies to help those who are unsure of how to increase their physical activity. OBJECTIVE: The aim of this pilot study is to test the efficacy of a new app, StepMATE, for increasing daily walking in a sample of inactive adults and to examine daily relationships between walking and self-reported mood and energy. METHODS: The participants were middle-aged and older adults aged ≥50 years (mean 61.64, SD 7.67 years). They were randomly assigned to receive either a basic, pedometer-like version of the app or a version with supports to help them determine where, when, and with whom to walk. Of the 96 participants randomized to 1 of 2 conditions, 87 (91%) completed pretest assessments and 81 (84%) successfully downloaded the app. Upon downloading the app, step data from the week prior were automatically recorded. The participants in both groups were asked to set a daily walking goal, which they could change at any point during the intervention. They were asked to use the app as much as possible over the next 4 weeks. Twice per day, pop-up notifications assessed mood and energy levels. RESULTS: Although one group had access to additional app features, both groups used the app in a similar way, mainly using just the walk-tracking feature. Multilevel models revealed that both groups took significantly more steps during the 4-week study than during the week before downloading the app (γ=0.24; P<.001). During the study, the participants in both groups averaged 5248 steps per day compared with an average of 3753 steps per day during the baseline week. Contrary to predictions, there were no differences in step increases between the two conditions. Cognition significantly improved from pre- to posttest (γ=0.17; P=.02). Across conditions, on days in which the participants took more steps than average, they reported better mood and higher energy levels on the same day and better mood on the subsequent day. Daily associations among walking, mood, and energy were significant for women but not for men and were stronger for older participants (those aged ≥62 years) than for the younger participants. CONCLUSIONS: Both groups increased their steps to a similar extent, suggesting that setting and monitoring daily walking goals was sufficient for an initial increase and maintenance of steps. Across conditions, walking had benefits for positive mood and energy levels, particularly for women and older participants. Further investigations should identify other motivating factors that could lead to greater and more sustained increases in physical activity. TRIAL REGISTRATION: ClinicalTrials.gov NCT03124537; https://clinicaltrials.gov/ct2/show/NCT03124537.

The Relationship of Personality and Behavior Change in a Physical Activity Intervention: The Role of Conscientiousness and Healthy Neuroticism.

This study examined the role of personality traits in a 5-week physical activity intervention study for working adults. We tested whether personality traits predicted individual differences in change in daily steps over time. Fifty-two participants ages 35 to 69 (M age = 49.71, SD = 8.64) wore a Fitbit Zip step counter for 35 days and completed a personality questionnaire. Participants were randomly assigned to either an implementation intention group or a control group. Both groups wore a Fitbit and had the goal to increase their daily steps. For the present study, the sample was collapsed across groups. Higher conscientiousness was associated with greater increases in daily steps. Also, individuals with healthy neuroticism, the combination of higher neuroticism and higher conscientiousness, showed greater increases in daily steps. The findings highlight that the efficacy of physical activity interventions may depend on personality traits. Intervention outcomes may be improved if personality is taken into account when designing the programs.

Walk to a better night of sleep: testing the relationship between physical activity and sleep.

OBJECTIVES: Many do not sleep well, particularly middle-aged and older adults. Physical activity (PA) shows promise for improving sleep; however, populations with clinical sleep disturbances have been a research focus. It remains unclear whether low-impact daily PA, like walking, can affect sleep in healthy adults. DESIGN: The current study was embedded within a 4-week randomized controlled trial to increase PA. SETTING: Participants from the greater Boston area were recruited to participate in a 4-week walking intervention on a rolling basis between October 2015 and August 2016. PARTICIPANTS: Fifty-nine participants (72% female) were enrolled in the study, with an average age of 49.43 (±8.40) years. INTERVENTION: The 4-week intervention was aimed at increasing participants' daily steps as the primary outcome. The current, supplementary study examined relationships between monthly and daily PA and sleep. MEASUREMENTS: Steps and active minutes were measured daily using a Fitbit Zip. Self-reports of sleep quality and duration were assessed daily, along with before and after the intervention. RESULTS AND CONCLUSIONS: Averaged across the month, daily active minutes were positively related to sleep quality but not duration. Sex moderated this relationship; women who took more steps and were more active reported sleeping better than those less active. Within persons, on days that participants were more active than average, they reported better sleep quality and duration in both sexes. Results suggest that low-impact PA is positively related to sleep, more so in women than men. Findings also showed that PA plays a greater role in predicting sleep quality than duration.

Time for change: using implementation intentions to promote physical activity in a randomised pilot trial.

OBJECTIVE: A common barrier to exercise is a perceived lack of time. The current pilot study examined the effects of an implementation intention intervention to enhance exercise self-efficacy, increase confidence to exercise when facing time constraints, and increase physical activity in middle-aged adults (n = 63, aged 35-69). DESIGN: Participants received a pedometer (Fitbit) to objectively measure activity and were randomly assigned to either a control or intervention condition. After a 1-week baseline, the intervention condition received instructions to plan how, where, and when they would add steps to their daily routine to meet their step goal, using personalised schedules and maps. Both groups were contacted nightly via email. MAIN OUTCOME MEASURES: Physical activity (steps and time spent in moderate-to-vigorous activity), goal achievement, exercise self-efficacy, time-relevant exercise self-efficacy and affect. RESULTS: Compared to the control, the intervention condition significantly increased in steps, time spent in moderate-to-vigorous activity, and time-relevant exercise self-efficacy. Goal achievement was related to greater time-relevant exercise self-efficacy and more positive affect at the daily level. CONCLUSION: Findings suggest that the personalised planning intervention increased physical activity and confidence in achieving physical activity goals under time constraints. Avenues for future directions, especially for producing more sustained effects, are discussed.