Heritability of Sleep and Its Disorders in Childhood and Adolescence

Purpose of Review This review summarizes recent literature on the heritability of sleep and sleep disorders in childhood and adolescence. We also identify gaps in the literature and priorities for future research. Recent Findings Findings indicate that age, measurement method, reporter, and timing of sleep measurements can influence heritability estimates. Recent genome-wide association studies (GWAS) have identified differences in the heritability of sleep problems when ancestral differences are considered, but sample sizes are small compared to adult GWAS. Most studies focus on sleep variables in the full range rather than on disorder. Studies using objective measures of sleep typically comprised small samples. Summary Current evidence demonstrates a wide range of heritability estimates across sleep phenotypes in childhood and adolescence, but research in larger samples, particularly using objective sleep measures and GWAS, is needed. Further understanding of environmental mechanisms and the interaction between genes and environment is key for future research.

Pathophysiology of Obstructive Sleep Apnea in Aging Women

The following review is designed to explore the pathophysiology of sleep apnea in aging women. The review initially introduces four endotypes (i.e., a more collapsible airway, upper airway muscle responsiveness, arousal threshold, and loop gain) that may have a role in the initiation of obstructive sleep apnea. Thereafter, sex differences in the prevalence of sleep apnea are considered along with differences in the prevalence that exist between younger and older women. Following this discussion, we consider how each endotype might contribute to the increase in prevalence of sleep apnea in aging women. Lastly, we address how modifications in one form of respiratory plasticity, long-term facilitation, that might serve to mitigate apneic events in younger women may be modified in aging women with obstructive sleep apnea. Overall, the published literature indicates that the prevalence of sleep apnea is increased in aging women. This increase is linked primarily to a more collapsible airway and possibly to reduced responsiveness of upper airway muscle activity. In contrast, modifications in loop gain or the arousal threshold do not appear to have a role in the increased prevalence of sleep apnea in aging women. Moreover, we suggest that mitigation of long-term facilitation could contribute to the increased prevalence of sleep apnea in aging women.

What Is “Chronic” in “Chronic Sleep Reduction” and What Are Its Consequences? A Systematic Scoping Review of the Literature

Purpose of Review In this scoping review, we aimed to (1) provide an overview of chronic sleep reduction by systematically reviewing the existing literature (limited to systematic reviews and meta-analyses), (2) investigate the evidence of the effects of short sleep duration on daytime functioning, and (3) identify research gaps in this field. Recent Findings The results showed that (1) clear definitions of chronicity of sleep reduction are lacking—none of the included reviews/meta-analyses provided a full definition—and (2) short sleep duration appeared to be related to obesity and diabetes, whereas relations with cardiovascular disease (CVD), cognitive functioning, emotional problems, general health, and mortality, showed either small effects and appeared to be complex (e.g., for CVD and cognitive functioning), or studies were scarce or completely lacking (e.g., mortality in children/adolescents and emotional problems in adults). Summary Although short or insufficient sleep is highly prevalent and is associated with impaired mental and physical wellbeing, as well as pervasive negative consequences for daytime functioning, the concepts of “chronicity” and “chronic sleep reduction” have not been clearly defined and its effects on health are therefore still largely unknown. Moreover, there are large research gaps concerning studies on the relations between short sleep and health consequences. Further studies are recommended to define and operationalize chronicity of sleep reduction and develop measurements that adequately represent the complexity of the concept.

The Associations of Obstructive Sleep Apnea and Eye Disorders: Potential Insights into Pathogenesis and Treatment

Purpose of Review Obstructive sleep apnea (OSA) patients are at significantly increased risks for cardiovascular and cerebrovascular morbidities. Recently, there has been heightened interest in the association of OSA with numerous ocular diseases and possible improvement of these conditions with the initiation of OSA treatment. We reviewed the current evidence with an emphasis on the overlapping pathogeneses of both diseases. Recent Findings Currently available literature points to a substantial association of OSA with ocular diseases, ranging from those involving the eyelid to optic neuropathies and retinal vascular diseases. Since the retina is one of the highest oxygen-consuming tissues in the body, the intermittent hypoxia and hypercapnia ensuing in OSA can have deleterious effects on ocular function and health. Tissue hypoxia, autonomic dysfunction, microvascular dysfunction, and inflammation all play important roles in the pathogenesis of both OSA and ocular diseases. Whether OSA treatment is capable of reversing the course of associated ocular diseases remains to be determined. It is anticipated that future therapeutic approaches will target the common underlying pathophysiologic mechanisms and promote favorable effects on the treatment of known associated ocular diseases. Summary Emerging evidence supports the association of ocular diseases with untreated OSA. Future studies focusing on whether therapeutic approaches targeting the common pathophysiologic mechanisms will be beneficial for the course of both diseases are warranted.