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

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.

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.