Seasonal variations in sleep duration and sleep complaints: A Swedish cohort study in middle-aged and older individuals

Greenspace proximity in relation to sleep health among a racially and ethnically diverse cohort of US women

Sleep is essential for overall health. Greenspace may contribute to sleep health through, for instance, improving mood, reducing sleep disruptors (e.g., poor air quality), and promoting physical activity. Although greenspace likely differs across populations, few studies have included diverse populations. To investigate greenspace-sleep health associations, overall and by age, race and ethnicity, and socioeconomic status, we used data collected at enrollment (2003-2009) from women in the Sister Study (n=1,612 Hispanic/Latina, n=4,421 non-Hispanic (NH)-Black, and n=41,657 NH-White). Participants' geocoded home addresses were linked to NASA's Moderate Resolution Imaging Spectroradiometer Normalized Difference Vegetation Index data (250m resolution) to capture greenspace tertiles (further categorized as low/moderate vs. high). Participants reported seven sleep dimensions, which we assessed individually, along with a multidimensional sleep health measure (categories: favorable, moderate, poor). Adjusting for individual- and environmental/neighborhood-level characteristics, we used Poisson regression with robust variance to estimate prevalence ratios and 95% confidence intervals (PR[CI]). We tested for interaction and estimated age-, race and ethnicity-, and educational attainment category-specific associations. Among participants (mean±SD age=55.7±9.0 years), those with low/moderate vs. high greenspace had a lower prevalence of favorable sleep (58% vs. 66%). After adjustment, low/moderate vs. high greenspace was associated with a 32% higher prevalence of moderate (PR=1.32 [1.27-1.38]) and 12% higher prevalence of poor (PR=1.12 [1.07-1.16]) vs. favorable sleep health. Magnitudes of associations were higher among NH-White women vs. minoritized racial-ethnic groups and women with higher vs. lower educational attainment. Higher greenspace was associated with favorable sleep, with stronger associations among groups with more social advantages.

Variability of excessive daytime sleepiness and cataplexy according to seasonality: A study in central disorders of hypersomnolence

Seasonality of excessive daytime sleepiness has been proposed, yet no research has specifically investigated its impact on daytime sleepiness and cataplexy in central disorders of hypersomnolence. This study examined seasonal variations in daytime sleepiness and cataplexy in narcolepsy type 1, narcolepsy type 2 and idiopathic hypersomnia. Patients included in the study were on stable pharmacological treatment, and participated in sleep medicine interviews to assess diurnal sleepiness and daytime napping and completed the Epworth Sleepiness Scale to assess excessive daytime sleepiness (Epworth Sleepiness Scale ≥ 10). Patients with narcolepsy type 1 also maintained a cataplexy diary. Evaluations were conducted in autumn, winter, spring and summer. The study included 29 patients with narcolepsy type 1, 16 patients with narcolepsy type 2 and 10 patients with idiopathic hypersomnia. Patients with narcolepsy type 1 and narcolepsy type 2 showed higher Epworth Sleepiness Scale scores in summer compared with other seasons, while patients with idiopathic hypersomnia showed no changes in excessive daytime sleepiness across the four seasons. Epworth Sleepiness Scale scores were higher in idiopathic hypersomnia patients compared to narcolepsy type 1 and narcolepsy type 2 patients in spring, autumn, and winter; conversely, in summer there were no differences in Epworth Sleepiness Scale scores among the three groups. No significant differences in Epworth Sleepiness Scale scores were noted between patients with narcolepsy type 1 and narcolepsy type 2 throughout the year. Furthermore, no seasonal effect on cataplexy frequency was found in patients with narcolepsy type 1. This study demonstrates that seasonality may influence daytime sleepiness in patients with narcolepsy type 1 and narcolepsy type 2 but not in patients with idiopathic hypersomnia, while cataplexy symptoms remain unaffected by seasonal changes. The underlying mechanisms linking excessive daytime sleepiness to seasonality have yet to be explored, though social factors and vacation time may contribute to increased excessive daytime sleepiness in narcolepsy.

Individual sleep need is flexible and dynamically related to cognitive function

Given that sleep deprivation studies consistently show that short sleep causes neurocognitive deficits, the effects of insufficient sleep on brain health and cognition are of great interest and concern. Here we argue that experimentally restricted sleep is not a good model for understanding the normal functions of sleep in naturalistic settings. Cross-disciplinary research suggests that human sleep is remarkably dependent on environmental conditions and social norms, thus escaping universally applicable rules. Sleep need varies over time and differs between individuals, showing a complex relationship with neurocognitive function. This aspect of sleep is rarely addressed in experimental work and is not reflected in expert recommendations about sleep duration. We recommend focusing on the role of individual and environmental factors to improve our understanding of the relationship between human sleep and cognition.

Evolution of Sleep Complaints in Myotonic Dystrophy Type 1: A 9-Year Longitudinal Study

The objective was to characterize the progression of sleep complaints in 115 dystrophy type 1 (DM1) patients who filled out a sleep questionnaire twice at a 9-year interval. Daytime napping (22.1% vs. 34.5%, p < 0.05), early awakenings (11.4% vs 21.1%, p < 0.05), nonrestorative sleep (39.5% vs 51.8%, p < 0.05), stimulant use (7.0% vs 19.3%, p < 0.01), breathing cessation (10.7% vs 23.2%, p < 0.01), and nighttime urination (42.5% vs 54.9%, p < 0.05) increased between Time 1 and Time 2. Sleep-related complaints are prominent and augment rapidly in DM1 patients. Physicians need to better identify and treat them to help alleviate the burden they impose on patients and their caregivers.

Effects of Season and Daylight Saving Time Shifts on Sleep Symptoms: Canadian Longitudinal Study on Aging

BACKGROUND AND OBJECTIVES

There has been conflicting evidence regarding the association between seasonal changes and daylight saving time (DST) and sleep disorders. This topic is of particular interest currently because the United States and Canada are considering the elimination of seasonal clock changes. The aim of this study was to compare sleep symptoms among participants who were interviewed in different seasons and before/after the transition into DST and standard time (ST).

METHODS

A total of 30,097 people aged 45-85 years taking part in the Canadian Longitudinal Study on Aging were studied. Participants completed a questionnaire on sleep duration, satisfaction, sleep-onset insomnia, sleep-maintenance insomnia, and hypersomnolence symptoms. Sleep disorders were compared between participants who were interviewed during different seasons and at different times of the year (DST/ST). Data were analyzed using χ2, analysis of variance, binary logistic, and linear regression tests.

RESULTS

Among participants interviewed in different seasons, we found no difference in dissatisfaction with sleep, sleep onset, sleep maintenance, and hypersomnolence. Those interviewed in summer had slightly shorter sleep duration compared with those in winter (6.76 ± 1.2 vs 6.84 ± 1.3 hours). Participants interviewed 1 week before vs 1 week after DST transition showed no difference in sleep symptoms, except for a 9-minute decrease in sleep duration a week after transition. However, those who were interviewed a week after transition to ST compared with a week before reported more dissatisfaction with sleep (28% vs 22.6%, adjusted odds ratio [aOR] 1.34, 95% CI 1.02-1.76), higher sleep-onset insomnia (7.1% vs 3.3%, aOR 2.26, 95% CI 1.19-4.27), higher sleep-maintenance insomnia (12.9% vs 8.2%, aOR 1.64, 95% CI 1.02-2.66), and more hypersomnolence with adequate sleep (7.3% vs 3.6%, aOR 2.08, 95% CI 1.14-3.79).

DISCUSSION

We found small seasonal variations in sleep duration but no difference in other sleep symptoms. The transition from DST to ST was associated with a transient increase in sleep disorders.

Chronic Insomnia Disorder across Europe: Expert Opinion on Challenges and Opportunities to Improve Care

One in ten adults in Europe have chronic insomnia, which is characterised by frequent and persistent difficulties initiating and/or maintaining sleep and daily functioning impairments. Regional differences in practices and access to healthcare services lead to variable clinical care across Europe. Typically, a patient with chronic insomnia (a) will usually present to a primary care physician; (b) will not be offered cognitive behavioural therapy for insomnia-the recommended first-line treatment; (c) will instead receive sleep hygiene recommendations and eventually pharmacotherapy to manage their long-term condition; and (d) will use medications such as GABA receptor agonists for longer than the approved duration. Available evidence suggests that patients in Europe have multiple unmet needs, and actions for clearer diagnosis of chronic insomnia and effective management of this condition are long overdue. In this article, we provide an update on the clinical management of chronic insomnia in Europe. Old and new treatments are summarised with information on indications, contraindications, precautions, warnings, and side effects. Challenges of treating chronic insomnia in European healthcare systems, considering patients' perspectives and preferences are presented and discussed. Finally, suggestions are provided-with healthcare providers and healthcare policy makers in mind-for strategies to achieve the optimal clinical management.

Seasonal variation of vasopressin and its relevance for the winter peak of cardiometabolic disease: A pooled analysis of five cohorts

BACKGROUND

Vasopressin concentration is typically higher at night, during stress, and in males, but readily lowered by water intake. Vasopressin is also a causal candidate for cardiometabolic disease, which shows seasonal variation.

OBJECTIVE

To study whether vasopressin concentration varies by season in a temperate climate.

METHODS

The vasopressin surrogate marker copeptin was analyzed in fasting plasma samples from five population-based cohorts in Malmö, Sweden (n = 25,907, 50.4% women, age 18-86 years). We investigated seasonal variation of copeptin concentration and adjusted for confounders in sinusoidal models.

RESULTS

The predicted median copeptin level was 5.81 pmol/L (7.18 pmol/L for men and 4.44 pmol/L for women). Copeptin exhibited a distinct seasonal pattern with a peak in winter (mid-February to mid-March) and nadir in late summer (mid-August to mid-September). The adjusted absolute seasonal variation in median copeptin was 0.62 pmol/L (95% confidence interval [CI] 0.50; 0.74, 0.98 pmol/L [95% CI 0.73; 1.23] for men and 0.46 pmol/L [95% CI 0.33; 0.59] for women). The adjusted relative seasonal variation in mean log copeptin z-score was 0.20 (95% CI 0.17; 0.24, 0.18 [95% CI 0.14; 0.23] in men and 0.24 [95% CI 0.19; 0.29] in women). The observed seasonal variation of copeptin corresponded to a risk increase of 4% for incident diabetes mellitus and 2% for incident coronary artery disease.

CONCLUSION

The seasonal variation of the vasopressin marker copeptin corresponds to increased disease risk and mirrors the known variation in cardiometabolic status across the year. Moderately increased water intake might mitigate the winter peak of cardiometabolic disease.

Sleep health composites are associated with the risk of heart disease across sex and race

We examined whether subjectively and objectively measured sleep health composites have a relationship with heart disease. 6,820 adults (M_age = 53.4 years) from the Midlife in the United States study provided self-reported sleep characteristics and heart disease history. A smaller sample (n = 663) provided actigraphy sleep data. We tested two sleep health composites, based on self-report only and both self-report and actigraphy, across multiple sleep dimensions. We used a weighted sum approach, where higher scores indicated more sleep health problems. Modified Poisson regressions adjusted for sociodemographics and known risk factors. Having more sleep health problems was associated with a higher risk of heart disease using the self-report sleep health composite (aRR = 54%, P < .001) and the actigraphy/self-report composite (aRR = 141%, P < .001). Individual sleep dimensions of satisfaction, alertness, and efficiency (from the self-report composite) and regularity, satisfaction, and timing (from the actigraphy/self-report composite) were associated with the risk of heart disease. The effect size of each sleep health composite was larger than the individual sleep dimensions. Race moderated the association between the actigraphy/self-report sleep health composite and heart disease. There was no significant moderation by sex. Findings suggest poorer sleep health across multiple dimensions may contribute to heart disease risk among middle-aged adults.