Do sleep complaints contribute to age-related cognitive decline?

Mechanisms of cognitive behavioural therapy for insomnia

Although much is known now about behavioural, cognitive and physiological consequences of insomnia, little is known about changes after cognitive behavioural therapy for insomnia on these particular factors. We here report baseline findings on each of these factors in insomnia, after which we address findings on their changes after cognitive behavioural therapy. Sleep restriction remains the strongest determinant of insomnia treatment success. Cognitive interventions addressing dysfunctional beliefs and attitudes about sleep, sleep-related selective attention, worry and rumination further drive effectiveness of cognitive behavioural therapy for insomnia. Future studies should focus on physiological changes after cognitive behavioural therapy for insomnia, such as changes in hyperarousal and brain activity, as literature on these changes is sparse. We introduce a detailed clinical research agenda on how to address this topic.

Cardiorespiratory Fitness May Protect Memory for Poorer Sleepers

OBJECTIVES

Physical activity has been shown to protect executive functions against the deleterious effects of poorer sleep among older adults (OA); however, it is unknown whether memory is protected too, and if this relationship differs by age. The present study investigated the relationship between cardiorespiratory fitness, sleep, and memory in both older and young adults (YA).

METHODS

This observational study recruited 26 OA (70.7 ± 2.8 years) and 35 YA (21.0 ± 3.1 years). Participants completed the Rockport 1-mile walk test to evaluate cardiorespiratory fitness. Participants wore an actigraph for 1 week to measure habitual sleep and returned for a second visit to perform the memory tests. The interaction between cardiorespiratory fitness and sleep to predict memory was assessed separately in OA and YA.

RESULTS

In OA, cardiorespiratory fitness significantly moderated the relationship between memory and sleep quality, specifically number of nighttime awakenings, sleep efficiency, and wake after sleep onset. Further analyses reveal that a high number of nighttime awakenings and low sleep efficiency significantly predicted worse memory performance in the low fit OA, but high fit OA. Notably, every nighttime awakening was associated with a nearly 4% decrease in memory in low fit OA, but not high fit OA. Wake after sleep onset did not significantly predict memory in either fitness group. No interaction was found when looking at sleep duration or self-report sleep quality in OA and no significant interactions were observed between fitness, sleep, and memory in YA.

CONCLUSION

Overall, the results suggest that cardiorespiratory fitness may act as a protective buffer for memory in OA with poor sleep quality. These same was not true for YA suggesting that the protective effects of cardiorespiratory fitness on sleep-related memory impairments may be age specific.

Differential effect of sleep deprivation on place cell representations, sleep architecture, and memory in young and old mice

Poor sleep quality is associated with age-related cognitive decline, and whether reversal of these alterations is possible is unknown. In this study, we report how sleep deprivation (SD) affects hippocampal representations, sleep patterns, and memory in young and old mice. After training in a hippocampus-dependent object-place recognition (OPR) task, control animals sleep ad libitum, although experimental animals undergo 5 h of SD, followed by recovery sleep. Young controls and old SD mice exhibit successful OPR memory, whereas young SD and old control mice are impaired. Successful performance is associated with two cellular phenotypes: (1) "context" cells, which remain stable throughout training and testing, and (2) "object configuration" cells, which remap when objects are introduced to the context and during testing. Additionally, effective memory correlates with spindle counts during non-rapid eye movement (NREM)/rapid eye movement (REM) sigma transitions. These results suggest SD may serve to ameliorate age-related memory deficits and allow hippocampal representations to adapt to changing environments.

Gender difference in health issues and cognitive functions among an Egyptian normal elderly population

Background

Aging is associated with changes in cognitive functions. However, many other factors may affect cognitive functions and this interaction needs further assessment.

Objectives

To detect gender differences in sleep quality, nutritional status, and health-related quality of life and their impact on performance in verbal fluency tasks among apparently healthy elderly.

Subjects and methods

The study was conducted on 102 normal aged subjects, 51 males and 51 females. Subjects were divided according to age into group ≥ 60 years and group < 60 years as a control. They were subjected to clinical assessment, Medical outcome study Short-Form 36-item Health Survey, Pittsburgh sleep quality index, mini nutritional assessment and Category Verbal fluency for animals and girls’ names.

Results

Among the older group, females had significantly poorer physical and mental health, sleep quality and nutritional status than males (p value 0.001, 0.003, 0.012, and 0.014, respectively). Older females had significantly lower performance in verbal fluency (girls’ names) compared to younger females (p value 0.013), but no significant gender difference was found among the older group. Verbal fluency tasks are correlated to the level of education in both males and females (r 0.392 and 0.42, p value 0.029 and 0.019, respectively), However, in older males, it is also correlated to sleep latency (r 0.41 and p value 0.021).

Conclusion

Older females had poorer sleep quality, lower health-related quality of life and lower nutritional status. No gender difference was found in verbal fluency tasks. Although no single variable could independently affect verbal fluency, education remains the main player in the difference in performance.

Economic aspects of insomnia medication treatment among Medicare beneficiaries

STUDY OBJECTIVES

To examine economic aspects of insomnia and insomnia medication treatment among a nationally representative sample of older adult Medicare beneficiaries.

METHODS

Using a random 5% sample of Medicare administrative data (2006-2013), insomnia was defined using International Classification of Disease, Version 9, Clinical Modification diagnostic codes. Treatment was operationalized as one or more prescription fills for an US Food and Drug Administration (FDA)-approved insomnia medication following diagnosis, in previously untreated individuals. To evaluate the economic impact of insomnia treatment on healthcare utilization (HCU) and costs in the year following insomnia diagnosis, a difference-in-differences approach was implemented using generalized linear models.

RESULTS

A total of 23 079 beneficiaries with insomnia (M age = 71.7 years) were included. Of these, 5154 (22%) received one or more fills for an FDA-approved insomnia medication following insomnia diagnosis. For both treated and untreated individuals, HCU and costs increased during the 12 months prior to diagnosis. Insomnia treatment was associated with significantly increased emergency department visits and prescription fills in the year following insomnia diagnosis. After accounting for pre-diagnosis differences between groups, no significant differences in pre- to post-diagnosis costs were observed between treated and untreated individuals.

CONCLUSIONS

These results advance previous research into economics of insomnia disorder by evaluating the impact of medication treatment and highlighting important differences between treated and untreated individuals. Future studies should seek to understand why some individuals diagnosed with insomnia receive treatment but others do not, to identify clinically meaningful clusters of older adults with insomnia, and to explore the economic impact of insomnia and insomnia treatment among subgroups of individuals with insomnia, such as those with cardiovascular diseases, mood disorders, and neurodegenerative disease.

Does restless legs syndrome impact cognitive function via sleep quality in adults with Parkinson's disease?

Purpose: Restless legs syndrome (RLS) is a sleep disorder that results in sleep dysfunction. Sleep disruption can have profound negative consequences in adults with Parkinson's disease (PD), potentially including cognitive dysfunction. This study examined the relationships among RLS, cognition, and sleep quality in persons with PD.Materials and methods: Participants (N = 79) with idiopathic PD completed six questionnaires evaluating RLS, sleep quality, daytime sleepiness, global cognitive function, sleep apnea risk, and depression. Participants were further examined for body mass index composition and motor symptom severity (MDS-UPDRS Part III).Results: Persons with RLS (n = 25) had significantly worse cognitive function (p = 0.035, d = -0.56) and sleep quality (p < 0.0001, d = -1.19), and more daytime sleepiness (p = 0.009, d = 0.67) than those without RLS (n = 54). Cognitive function was not significantly correlated with sleep quality (rs = 0.113) or daytime sleepiness (rs = -0.001). The association between RLS and cognition was not attenuated by controlling for sleep quality or daytime sleepiness.Conclusions: This study is unique as it is the first to consider the possibility that RLS in PD may be associated with cognitive deficits through a pathway involving sleep quality. Persons with RLS and PD have greater deficits in both sleep quality and cognitive function than individuals without RLS; however, cognitive dysfunction among those with PD and RLS in this sample is not accounted for by sleep quality.

Factors associated with the sleep of carers: A survey of New Zealanders supporting a family member with cognitive impairment or dementia

Sleep is important for healthy ageing. Data are limited concerning the sleep and health of New Zealand families affected by cognitive impairment or dementia. This postal survey asked about the sleep of 526 family carers and explored predictors of, and outcomes associated with poorer sleep. Linear and binominal logistic regression were used to identify independent predictors and outcomes of carers' sleep status. Using the Insomnia Severity Index, 23.5% of carers scored in the moderate-severe range and 43.0% in the mild range for sleep disturbance. More than a quarter indicated that their family member had difficulties falling asleep, getting up during the night, or waking too early. Over half of care recipients were considered to sleep too much during the day. Independent predictors for carers' reporting greater sleep disturbance included being female, caregiving at night, poorer self-rated health, and the care recipient having more disturbed sleep. Moderate-severe sleep disturbance was independently associated with poorer self-rated health and living standards, use of sleeping medications, as well as considering transitioning their family member into formal care within the year. These findings have implications for the wellbeing and trajectory of family carers as well as for health and aged care services.

Untreated insomnia increases all-cause health care utilization and costs among Medicare beneficiaries

STUDY OBJECTIVES

To examine the impact of untreated insomnia on health care utilization (HCU) among a nationally representative sample of Medicare beneficiaries.

METHODS

Our data source was a random 5% sample of Medicare administrative data for years 2006-2013. Insomnia was operationalized as the presence of at least one claim containing an insomnia-related diagnosis in any given year based on International Classification of Disease, Version 9, Clinical Modification codes or at least one prescription fill for an insomnia-related medication in Part D prescription drug files in each year. We compared HCU in the year prior to insomnia diagnosis to HCU among to non-sleep disordered controls during the same period.

RESULTS

A total of 151 668 beneficiaries were found to have insomnia. Compared to controls (n = 333 038), beneficiaries with insomnia had higher rates of HCU across all point of service locations. Rates of HCU were highest for inpatient care (rate ratio [RR] 1.61; 95% confidence interval [CI] 1.59, 1.64) and lowest for prescription fills (RR 1.17; 95% CI 1.16, 1.17). Similarly, compared to controls, beneficiaries with insomnia demonstrated $63,607 (95% CI $60,532, $66,685) higher all-cause costs, which were driven primarily by inpatient care ($60,900; 95% CI $56,609, $65,191). Emergency department ($1,492; 95% CI $1,387, $1,596) and prescription costs ($486; 95% CI $454, $518) were also elevated among cases relative to controls.

CONCLUSIONS

In this randomly selected and nationally representative sample of older Medicare beneficiaries and compared to non-sleep disordered controls, individuals with untreated insomnia demonstrated increased HCU and costs across all points of service.

Cognitive complaints in cancer survivors and expectations for support: Results from a web-based survey

Background

Cognitive complaints are common in cancer survivors. We aimed to assess cognitive complaints in cancer survivors and the associated factors using a large web–based survey.

Methods

This online survey was proposed to cancer survivors. Participants completed several questions on cognitive complaints experience, expectations for support of cognitive difficulties, preexisting knowledge about chemotherapy–associated cognitive problems and demographic and medical variables. We used multivariable logistic regression models to estimate Odds Ratios and 95% confidence intervals to estimate associations.

Results

Among 1610 eligible participants (median age 52 [21‐84]), >85% (n = 1393) were breast cancer survivors. Median postcancer treatment time (excluding hormone therapy) was 2.83 years [0.8‐33]. Seventy five percent of the participants (n = 1214) reported cognitive complaints related to cancer treatments. Cognitive difficulties had an impact on work resumption for 76% of the participants (n = 754/982). Most cancer survivors would like to receive support (75%, n = 909) and especially cognitive training (72%, n = 658). Chemotherapy was strongly associated with cognitive complaints (multivariable OR = 3.67, 95% CI: 2.80‐4.82). Self–reported sleep difficulties (OR_{often vs. never} = 2.84, 95% CI: 1.80‐4.47), preexisting knowledge about chemotherapy–associated cognitive problems (OR_{No vs. Yes} = 1.69, 95% CI: 1‐29‐2.22) and age (OR_{21‐64 vs. ≥65} = 0.37, 95% CI: 0.23‐0.58) were also associated with cancer–related cognitive complaints.

Conclusions

According to this large web–based survey including mainly breast cancer survivors, cognitive complaints were reported by three quarters of participants, which reinforces that cognitive difficulties are a major issue in cancer survivors. Chemotherapy, self–reported sleep difficulties and preexisting knowledge about chemotherapy–associated cognitive problems were strongly associated with cancer–related cognitive complaints. Most cancer survivors wished to receive support and especially cognitive training.

Effects of Aging on Cortical Neural Dynamics and Local Sleep Homeostasis in Mice

Healthy aging is associated with marked effects on sleep, including its daily amount and architecture, as well as the specific EEG oscillations. Neither the neurophysiological underpinnings nor the biological significance of these changes are understood, and crucially the question remains whether aging is associated with reduced sleep need or a diminished capacity to generate sufficient sleep. Here we tested the hypothesis that aging may affect local cortical networks, disrupting the capacity to generate and sustain sleep oscillations, and with it the local homeostatic response to sleep loss. We performed chronic recordings of cortical neural activity and local field potentials from the motor cortex in young and older male C57BL/6J mice, during spontaneous waking and sleep, as well as during sleep after sleep deprivation. In older animals, we observed an increase in the incidence of non-rapid eye movement sleep local field potential slow waves and their associated neuronal silent (OFF) periods, whereas the overall pattern of state-dependent cortical neuronal firing was generally similar between ages. Furthermore, we observed that the response to sleep deprivation at the level of local cortical network activity was not affected by aging. Our data thus suggest that the local cortical neural dynamics and local sleep homeostatic mechanisms, at least in the motor cortex, are not impaired during healthy senescence in mice. This indicates that powerful protective or compensatory mechanisms may exist to maintain neuronal function stable across the life span, counteracting global changes in sleep amount and architecture.

SIGNIFICANCE STATEMENT The biological significance of age-dependent changes in sleep is unknown but may reflect either a diminished sleep need or a reduced capacity to generate deep sleep stages. As aging has been linked to profound disruptions in cortical sleep oscillations and because sleep need is reflected in specific patterns of cortical activity, we performed chronic electrophysiological recordings of cortical neural activity during waking, sleep, and after sleep deprivation from young and older mice. We found that all main hallmarks of cortical activity during spontaneous sleep and recovery sleep after sleep deprivation were largely intact in older mice, suggesting that the well-described age-related changes in global sleep are unlikely to arise from a disruption of local network dynamics within the neocortex.

Residential road traffic noise exposure and colorectal cancer survival - A Danish cohort study

BACKGROUND

Residential traffic noise exposure may entail sleep disruption and compromised circadian functioning; two factors which have been associated with a poor colorectal cancer (CRC) prognosis. Hence, the aim of the present study was to investigate the association between residential road traffic noise and CRC survival.

METHODS AND MATERIALS

Road traffic noise was calculated for all residential addresses from 1987 to February 2012 for incident CRC cases (n = 1,234) in a cohort of 57,053 Danes. We used Cox Proportional Hazard Models to investigate the association between residential road traffic noise at different time-windows, and overall and CRC-specific mortality. Furthermore, we investigated interaction with sex, age, prognostic factors, and comorbidity. Mortality Rate Ratios (MRR) were calculated in unadjusted models, and adjusted for railway noise, lifestyle factors, and socioeconomic variables.

RESULTS

During a median follow-up of 4 years, 594 patients died; 447 from CRC. We found no association between road traffic noise exposure and overall (MRR 1.00 (0.88-1.13) per 10 dB) or CRC-specific mortality (MRR 0.98 (0.85-1.13) per 10 dB) over the entire follow-up period, or 1 year preceding death. Results did not differ when examining colon and rectal cancer separately. Interaction analyses suggested that patients with less clinically advanced disease could be more susceptible to harmful effects of traffic noise.

CONCLUSION

The present study suggests no overall association between residential road traffic noise and concurrent mortality in CRC patients. As it is the first study of its kind, with relatively limited power, further studies are warranted.

Sleep Deprivation Makes the Young Brain Resemble the Elderly Brain: A Large-Scale Brain Networks Study

Decreased cognition performance and impaired brain function are similar results of sleep deprivation (SD) and aging, according to mounted supporting evidence. Some investigators even proposed SD as a model of aging. However, few direct comparisons were ever explored between the effects of SD and aging by network module analysis with the resting-state functional magnetic resonance imaging. In this study, both within-module and between-module (BT) connectivities were calculated in the whole brain to describe a complete picture of brain networks' functional connectivity among three groups (young normal sleep, young SD, and old group). The results showed that the BT connectivities in subcortical and cerebellar networks were significantly declined in both the young SD group and old group. There were six other networks, that is, ventral attention, dorsal attention, default mode, auditory, cingulo-opercular, and memory retrieval networks, significantly influenced by aging. Therefore, we speculated that the effects of SD on the young group can be regarded as a simplified model of aging. Moreover, this provided a possible explanation, that is, the old were more tolerable for SD than the young. However, SD may not be a considerable model for aging when discussing the brain regions related to those SD-uninfluenced networks.

Upregulation of orexin/hypocretin expression in aged rats: Effects on feeding latency and neurotransmission in the insular cortex

Aging is associated with changes in numerous homeostatic functions, such as food intake, that are thought to be mediated by the hypothalamus. Orexin/hypocretin neurons of the hypothalamus regulate several physiological functions, including feeding, sleep and wakefulness. Evidence from both clinical and animal studies supports the notion that aging is associated with loss or dysregulation of the orexin system. Here, we used virus-mediated gene transfer to manipulate expression of orexin peptides in young and aged rats and examined behavioral and neurochemical correlates of food intake in these animals. Aged rats showed slower feeding latencies when presented with palatable food compared to young control rats, and these deficits were ameliorated by upregulation of orexin expression. Similarly, young animals treated with a virus designed to decrease preproorexin expression showed longer feeding latencies reminiscent of aged control rats. Feeding was also associated with increased acetylcholine, glutamate and GABA efflux in insular cortex of young control animals. Orexin upregulation did not restore deficits in feeding-elicited release of these neurotransmitters in aged rats, but did enhance basal neurotransmitter levels which may have contributed to the behavioral correlates of these genetic manipulations. These studies demonstrate that age-related deficits in behavioral and neurochemical measures of feeding are likely to be mediated, in part, by the orexin system. Because these same neurotransmitter systems have been shown to underlie orexin effects on cognition, treatments which increase orexin function may have potential for improving both physiological and cognitive manifestations of certain age-related disorders.

Memory improvement via slow-oscillatory stimulation during sleep in older adults

We examined the intriguing but controversial idea that disrupted sleep-dependent consolidation contributes to age-related memory decline. Slow-wave activity during sleep may help strengthen neural connections and provide memories with long-term stability, in which case decreased slow-wave activity in older adults could contribute to their weaker memories. One prediction from this account is that age-related memory deficits should be reduced by artificially enhancing slow-wave activity. In young adults, applying transcranial current oscillating at a slow frequency (0.75 Hz) during sleep improves memory. Here, we tested whether this procedure can improve memory in older adults. In 2 sessions separated by 1 week, we applied either slow-oscillatory stimulation or sham stimulation during an afternoon nap in a double-blind, crossover design. Memory tests were administered before and after sleep. A larger improvement in word-pair recall and higher slow-wave activity was observed with slow-oscillatory stimulation than with sham stimulation. This is the first demonstration that this procedure can improve memory in older adults, suggesting that declarative memory performance in older adults is partly dependent on slow-wave activity during sleep.

The effects of sleep deprivation on brain functioning in older adults

Few studies have examined the effects of total sleep deprivation (TSD) on cognitive performance and brain activation using functional MRI (fMRI) in older adults. The current study examines blood oxygen level-dependent (BOLD) activation in older adults and younger adults during the sustained attention (GO) and response inhibition (NOGO) portions of a GO-NOGO cognitive task following 36 hr of total sleep deprivation. No significant performance differences were observed between the groups on the behavioral outcome measures of total hits and false alarms. Neuroimaging results, however, revealed a significant interaction between age-group and sleep-deprivation status. Specifically, older adults showed greater BOLD activation as compared to younger adults after 36 hours total sleep deprivation in brain regions typically associated with attention and inhibitory processes. These results suggest in order for older adults to perform the GO-NOGO task effectively after sleep deprivation, they rely on compensatory recruitment of brain regions that aide in the maintenance of cognitive performance.

Associations of the 24-h activity rhythm and sleep with cognition: a population-based study of middle-aged and elderly persons

BACKGROUND

Cognitive functioning changes with age, sleep, and the circadian rhythm. We investigated whether these factors are independently associated with different cognitive domains assessed in middle-aged and elderly persons.

METHODS

In 1723 middle-aged and elderly persons (age 62 ± 9.4 years, mean ± standard deviation, SD) of the Rotterdam Study, we collected actigraphy recordings of on average 138 h. Actigraphy was used to quantify 24-h rhythms by calculating the stability of the rhythm over days and the fragmentation of the rhythm. Sleep parameters including total sleep time, sleep-onset latency, and wake after sleep onset were also estimated from actigraphy. Cognitive functioning was assessed with the word learning test (WLT), word fluency test (WFT), letter digit substitution task (LDST), and Stroop color word test (Stroop).

RESULTS

Persons with less stable 24-h rhythms performed worse on the LDST (B = 0.42 per SD increase, p = 0.004) and the Stroop interference trial (B = -1.04 per SD increase, p = 0.003) after full adjustment. Similarly, persons with more fragmented rhythms performed worse on the LDST (B = -0.47 per SD increase, p = 0.002) and the Stroop (B = 1.47 per SD increase, p <0.001). By contrast, longer observed sleep-onset latencies were related to worse performance on the WLT delayed recall (B = -0.19 per SD increase, p = 0.027) and the WFT (B = -0.45 per SD increase, p = 0.007).

CONCLUSIONS

Disturbances of sleep and the 24-h activity rhythm were independently related to cognition; while persons with longer sleep-onset latencies had worse performance on memory and verbal tasks, persons with 24-h rhythm disturbances performed less on executive functioning and perceptual speed tasks.

Sleep, cognition, and normal aging: integrating a half century of multidisciplinary research

Sleep is implicated in cognitive functioning in young adults. With increasing age, there are substantial changes to sleep quantity and quality, including changes to slow-wave sleep, spindle density, and sleep continuity/fragmentation. A provocative question for the field of cognitive aging is whether such changes in sleep physiology affect cognition (e.g., memory consolidation). We review nearly a half century of research across seven diverse correlational and experimental domains that historically have had little crosstalk. Broadly speaking, sleep and cognitive functions are often related in advancing age, though the prevalence of null effects in healthy older adults (including correlations in the unexpected, negative direction) indicates that age may be an effect modifier of these associations. We interpret the literature as suggesting that maintaining good sleep quality, at least in young adulthood and middle age, promotes better cognitive functioning and serves to protect against age-related cognitive declines.

Methodological challenges in studies of bright light therapy to treat sleep disorders in nursing home residents with dementia

AIM

Numerous studies have explored the effectiveness of bright light therapy as a treatment of sleep disorders in nursing home and long-stay geriatric hospital residents, most of whom have dementia. A recent Cochrane Collaboration meta-analysis of 10 selected studies concluded that there was insufficient evidence to assess its therapeutic efficacy as most available studies had methodological problems. We sought to remedy this situation by developing proposals to guide research methods in future studies.

METHODS

Based on the literature and our own clinical and research experience, we developed a series of proposals relating to study design, participant selection, light delivery modalities and outcome measures that we believe will maximize the chances of identifying a bright light treatment effect. We then checked adherence to these proposals in all relevant published experimental studies.

RESULTS

Of the 18 studies published in the last two decades that met our selection criteria, only half the studies had selected participants with a sleep disorder. Eleven studies excluded people with severe vision loss; seven included a clinical rating of sleep, and five measured baseline lighting levels. Most checked psychoactive medication prescriptions but few reported changes in prescriptions over the course of the study. Most also checked treatment adherence and included some control for differences in amount of social contact.

CONCLUSIONS

Evidence for the effectiveness of bright white light treatment in people residing in nursing homes is equivocal. We anticipate that the quality of this evidence will be improved if researchers refine their study methods and adopt a more uniform approach.

Add-on prolonged-release melatonin for cognitive function and sleep in mild to moderate Alzheimer's disease: a 6-month, randomized, placebo-controlled, multicenter trial

Purpose

A link between poor sleep quality and Alzheimer’s disease (AD) has recently been suggested. Since endogenous melatonin levels are already reduced at preclinical AD stages, it is important to ask whether replenishing the missing hormone would be beneficial in AD and whether any such effects would be related to the presence of sleep disorder in patients.

Patients and methods

The effects of add-on prolonged-release melatonin (PRM) (2 mg) to standard therapy on cognitive functioning and sleep were investigated in 80 patients (men [50.7%], women [49.3%], average age 75.3 years [range, 52–85 years]) diagnosed with mild to moderate AD, with and without insomnia comorbidity, and receiving standard therapy (acetylcholinesterase inhibitors with or without memantine). In this randomized, double-blind, parallel-group study, patients were treated for 2 weeks with placebo and then randomized (1:1) to receive 2 mg of PRM or placebo nightly for 24 weeks, followed by 2 weeks placebo. The AD Assessment Scale–Cognition (ADAS-Cog), Instrumental Activities of Daily Living (IADL), Mini–Mental State Examination (MMSE), sleep, as assessed by the Pittsburgh Sleep Quality Index (PSQI) and a daily sleep diary, and safety parameters were measured.

Results

Patients treated with PRM (24 weeks) had significantly better cognitive performance than those treated with placebo, as measured by the IADL (P=0.004) and MMSE (P=0.044). Mean ADAS-Cog did not differ between the groups. Sleep efficiency, as measured by the PSQI, component 4, was also better with PRM (P=0.017). In the comorbid insomnia (PSQI ≥6) subgroup, PRM treatment resulted in significant and clinically meaningful effects versus the placebo, in mean IADL (P=0.032), MMSE score (+1.5 versus −3 points) (P=0.0177), and sleep efficiency (P=0.04). Median ADAS-Cog values (−3.5 versus +3 points) (P=0.045) were significantly better with PRM. Differences were more significant at longer treatment duration. PRM was well tolerated, with an adverse event profile similar to that of placebo.

Conclusion

Add-on PRM has positive effects on cognitive functioning and sleep maintenance in AD patients compared with placebo, particularly in those with insomnia comorbidity. The results suggest a possible causal link between poor sleep and cognitive decline.

Coaching in healthy dietary practices in at-risk older adults: a case of indicated depression prevention

Prevention of major depressive disorder is important because current treatments are only partially adequate in reducing symptom burden and promoting health-related quality of life. Lifestyle interventions may be a desirable prevention strategy for reasons of patient preference, particularly among older patients from minority groups. Using evidence from a randomized depression prevention trial for older adults, the authors found that coaching in healthy dietary practices was potentially effective in protecting at-risk older adults from developing incident episodes of major depression. The authors describe the dietary coaching program (highlighted in a case example) as well as the feasibility and potential efficacy of the program within the context of evidence-based interventions for preventing episodes of major depression and mitigating symptoms of depression. Older adults receiving dietary coaching experienced a low incidence of major depressive episodes and exhibited a 40%-50% decrease in depressive symptoms, as well as enhanced well-being, during the initial 6-week intervention; these gains were sustained over 2 years. The authors also describe why lifestyle interventions like coaching in healthy dietary practices may hold promise as effective, practical, nonstigmatizing interventions for preventing episodes of major depressive disorder in older adults with subsyndromal depressive symptoms.

Aging in mice reduces the ability to sustain sleep/wake states

One of the most significant problems facing older individuals is difficulty staying asleep at night and awake during the day. Understanding the mechanisms by which the regulation of sleep/wake goes awry with age is a critical step in identifying novel therapeutic strategies to improve quality of life for the elderly. We measured wake, non-rapid eye movement (NREM) and rapid-eye movement (REM) sleep in young (2–4 months-old) and aged (22–24 months-old) C57BL6/NIA mice. We used both conventional measures (i.e., bout number and bout duration) and an innovative spike-and-slab statistical approach to characterize age-related fragmentation of sleep/wake. The short (spike) and long (slab) components of the spike-and-slab mixture model capture the distribution of bouts for each behavioral state in mice. Using this novel analytical approach, we found that aged animals are less able to sustain long episodes of wakefulness or NREM sleep. Additionally, spectral analysis of EEG recordings revealed that aging slows theta peak frequency, a correlate of arousal. These combined analyses provide a window into the mechanisms underlying the destabilization of long periods of sleep and wake and reduced vigilance that develop with aging.

Longitudinal course of insomnia: age-related differences in subjective sleepiness and vigilance performance in a population-based sample

OBJECTIVE

The present study utilized a population-based sample investigating the following aims: (1) compare the longitudinal course of insomnia in middle-aged and older adults and (2) examine age-related differences on subjective complaint and objective performance in middle-aged and older adults based on the course of insomnia.

METHODS

1657 middle-aged adults (48.16% male, mean age=55.35±4.03years) and 405 older adults (48.40% male, mean age=70.13±3.88years) from the Korean Genome and Epidemiology Study (KoGES) were classified into 4 groups - no insomnia (NI), single episode insomnia (SEI), remitted persistent insomnia (PI-R), and ongoing persistent insomnia (PI-O) based on their course of insomnia over 5 time points spaced two years apart. Their performance on the psychomotor vigilance task (PVT) and subjective daytime sleepiness were compared across different insomnia groups, and the results were compared between middle-aged adults and older adults.

RESULTS

Analysis of covariance indicated that subjective daytime sleepiness was significantly different across the insomnia groups in middle-aged adults based on insomnia group (P=<.0001), but, did not affect objective vigilance performance. In contrast, older adults displayed significantly different PVT response time, but not daytime sleepiness, based on insomnia group (P=0.03).

CONCLUSION

Insomnia impacts psychomotor performance and subjective sleepiness differently, based on age group. There may be underlying processes associated with the aging that amplifies the impact of insomnia on vigilance performance, yet lessens perceived sleepiness in older adults.

Excessive sleepiness is predictive of cognitive decline in the elderly

STUDY OBJECTIVES

To examine the association of sleep complaints reported at baseline (insomnia complaints and excessive daytime sleepiness (EDS)) and medication, with cognitive decline in community-dwelling elderly.

DESIGN

An 8-yr longitudinal study.

SETTING

The French Three-City Study.

PARTICIPANTS

There were 4,894 patients without dementia recruited from 3 French cities and having a Mini-Mental Status Examination (MMSE) score ≥ 24 points at baseline.

MEASUREMENTS AND RESULTS

Questionnaires were used to evaluate insomnia complaints (poor sleep quality (SQ), difficulty in initiating sleep (DIS), difficulty in maintaining sleep (DMS), early morning awakening (EMA)), EDS, and sleep medication at baseline. Cognitive decline was defined as a 4-point reduction in MMSE score during follow-up at 2, 4, and 8 yr. Logistic regression models were adjusted for sociodemographic, behavioral, physical, and mental health variables, and apolipoprotein E genotype. EDS independently increased the risk of cognitive decline (odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.02-1.56), especially for those patients who also developed dementia during the follow-up period (OR = 1.39, 95% CI = 1.00-1.97). The number of insomnia complaints and DMS were negatively associated with MMSE cognitive decline (OR = 0.77, 95% CI = 0.60-0.98 for 3-4 complaints, OR = 0.81, 95% CI = 0.68-0.96, respectively). The 3 other components of insomnia (SQ, DIS, EMA) were not significantly associated with MMSE cognitive decline.

CONCLUSIONS

Our results suggest that EDS may be associated independently with the risk of cognitive decline in the elderly population. Such results could have important public health implications because EDS may be an early marker and potentially reversible risk factor of cognitive decline and onset of dementia.

Does subjective sleep affect cognitive function in healthy elderly subjects? The Proof cohort

OBJECTIVE

Some epidemiological data are available on the association between sleep duration and sleep quality, sleep complaints, and the aging related cognitive impairment in the elderly. In this study we examined a large sample of healthy elderly subjects to assess the relationship between sleep quality, subjective cognitive complaints, and neuropsychological performance.

METHODS

A total of 272 elderly subjects (mean age 74.8 ± 1.1 years) were recruited from a population-based cross-sectional study on aging and cardiovascular morbidity. All subjects filled in self-assessment questionnaires evaluating cognitive function, anxiety, depression, sleep-related parameters, and the Pittsburgh Sleep Quality Index (PSQI). Ambulatory polygraphy and extensive neuropsychological tests were also performed. Based on the total PSQI score, subjects were classified as good sleepers (GS, PSQI<5, n=116) and poor sleepers (PS, PSQI≥5, n=156).

RESULTS

Poor sleep did not affect the subjective cognitive function score, subjective cognitive impairment being mainly related to anxiety, depression, and sleep medication intake. No significant differences were seen between GS and PS in any of the objective cognitive function tests except for the Trail Making Test A (TMA-A), processing speed being longer in the PS group (p<0.001). Neither the presence of sleep-related breathing disorders nor gender affected cognitive performance.

CONCLUSIONS

Our results suggest that in healthy elderly subjects, subjective sleep quality and duration did not significantly affect subjective and objective cognitive performances, except the attention level, for that the interference of sleep medication should be considered.

Habitual Sleep, Reasoning, and Processing Speed in Older Adults with Sleep Complaints

The relationship between habitual sleep and cognition in older adults with sleep complaints is poorly understood, because research has focused on younger adults, used experimental or retrospective quasi-experimental designs, and generally produced equivocal results. Prospective studies using sleep diaries are rare, but may provide important insights into this relationship as they offer greater ecological validity and allow for examination of the impact of night-to-night variability in sleep (an often overlooked aspect of sleep) on cognitive performance. Seventy-two older adults (M(age) = 70.18 years, SD(age) = 7.09 years) completed fourteen consecutive days of sleep diaries and paper/pencil self-administered cognitive tasks, including measures of processing speed (Symbol Digit) and reasoning (Letter Series). Regression analyses revealed increased average total wake time (TWT) during the night was associated with higher Symbol Digit scores, β = 0.45, P < 0.05. Night-to-night variability in either total sleep time (TST) or TWT was not associated with either cognitive measure. Implications and potential explanations for these initially counterintuitive findings are discussed.

Alzheimer's disease is not "brain aging": neuropathological, genetic, and epidemiological human studies

Human studies are reviewed concerning whether "aging"-related mechanisms contribute to Alzheimer's disease (AD) pathogenesis. AD is defined by specific neuropathology: neuritic amyloid plaques and neocortical neurofibrillary tangles. AD pathology is driven by genetic factors related not to aging per se, but instead to the amyloid precursor protein (APP). In contrast to genes involved in APP-related mechanisms, there is no firm connection between genes implicated in human "accelerated aging" diseases (progerias) and AD. The epidemiology of AD in advanced age is highly relevant but deceptively challenging to address given the low autopsy rates in most countries. In extreme old age, brain diseases other than AD approximate AD prevalence while the impact of AD pathology appears to peak by age 95 and decline thereafter. Many distinct brain diseases other than AD afflict older human brains and contribute to cognitive impairment. Additional prevalent pathologies include cerebrovascular disease and hippocampal sclerosis, both high-morbidity brain diseases that appear to peak in incidence later than AD chronologically. Because of these common brain diseases of extreme old age, the epidemiology differs between clinical "dementia" and the subset of dementia cases with AD pathology. Additional aging-associated mechanisms for cognitive decline such as diabetes and synapse loss have been linked to AD and these hypotheses are discussed. Criteria are proposed to define an "aging-linked" disease, and AD fails all of these criteria. In conclusion, it may be most fruitful to focus attention on specific pathways involved in AD rather than attributing it to an inevitable consequence of aging.