Increased Cerebrospinal Fluid Amyloid-β During Sleep Deprivation in Healthy Middle-Aged Adults Is Not Due to Stress or Circadian Disruption

BACKGROUND

Concentrations of soluble amyloid-β (Aβ) oscillate with the sleep-wake cycle in the interstitial fluid of mice and cerebrospinal fluid (CSF) of humans. Further, the concentration of Aβ in CSF increases during sleep deprivation. Stress and disruption of the circadian clock are additional mechanisms hypothesized to increase CSF Aβ levels. Cortisol is a marker for stress and has an endogenous circadian rhythm. Other factors such as glucose and lactate have been associated with changes in sleep-wake activity and/or Aβ.

OBJECTIVE

In this exploratory study, we used samples collected in a previous study to examine how sleep deprivation affects Aβ, cortisol, lactate, and glucose in plasma and CSF from healthy middle-aged adults (N = 11).

METHODS

Eleven cognitively normal participants without evidence of sleep disturbance were randomized to sleep deprivation or normal sleep control. All participants were invited to repeat the study. Cortisol, lactate, glucose, and Aβ were measured in 2-h intervals over a 36-h period in both plasma and CSF. All concentrations were normalized to the mean prior to calculating mesor, amplitude, acrophase, and other parameters.

RESULTS

One night of sleep deprivation increases the overnight concentration of Aβ in CSF approximately 10%, but does not significantly affect cortisol, lactate, or glucose concentrations in plasma or CSF between the sleep-deprived and control conditions.

CONCLUSION

These data suggest that sleep deprivation-related changes in CSF Aβ are not mediated by stress or circadian disruption as measured by cortisol.

Effect of sleep on overnight cerebrospinal fluid amyloid β kinetics

Sleep disturbances are associated with future risk of Alzheimer disease. Disrupted sleep increases soluble amyloid β, suggesting a mechanism for sleep disturbances to increase Alzheimer disease risk. We tested this response in humans using indwelling lumbar catheters to serially sample cerebrospinal fluid while participants were sleep-deprived, treated with sodium oxybate, or allowed to sleep normally. All participants were infused with ¹³ C₆ -leucine to measure amyloid β kinetics. We found that sleep deprivation increased overnight amyloid β38, amyloid β40, and amyloid β42 levels by 25 to 30% via increased overnight amyloid β production relative to sleeping controls. These findings suggest that disrupted sleep increases Alzheimer disease risk via increased amyloid β production. Ann Neurol 2018;83:197-204.

The magnon dynamics and spin exchange parameters of FePS3

The spin waves in a powdered sample of a quasi-two-dimensional antiferromagnet, FePS(3), have been measured using neutron inelastic scattering. The data could be modelled and the exchange interactions determined using a two-dimensional Heisenberg Hamiltonian with single ion anisotropy. A suitable fit to the data could only be achieved by including magnetic interactions up to the third nearest neighbour, which is consistent with the findings for other members of the MPS(3) family (M=transition metal). The best fit parameters at 6 K were J(1) = 1.49 meV, J(2) = 0.04 meV, J(3) =- 0.6 meV, with an anisotropy of Δ = 3.7 meV. Measurements as a function of temperature give a coarse measure of the behaviour of the anisotropy and the nature of the phase transition.

High energy excitations measured by neutron spectroscopy in FePS(3)

The quasi-two-dimensional antiferromagnet FePS(3) has been investigated using inelastic neutron spectroscopy with the time-of-flight spectrometer HET at the ISIS spallation neutron source. In the paramagnetic regime, two clearly resolved, high energy excitations were observed in the low scattering angle detector banks at 195(5) meV and 430(10) meV. The absence of these transitions from the high angle detector banks indicates that they are likely to be due to the crystal fields and magnetic in origin. The two transitions most probably represent electronic transitions in the Fe(2+) ion among the low lying crystal field and spin-orbit split levels raised from the ground state. It has not yet been determined why the energies are greater than those observed in a comparable Raman experiment.

Ethical implications of pain management in a nursing home: a discussion

Pain is the most frequently communicated complaint among elderly people. Discussion of the ethics of pain management in nursing home residents has not appeared in the literature. The purpose of this article is to present an ethically-based pain management action plan for elderly nursing home residents. Nurses empowered with the latest information and cognizant and comfortable with their own views about pain are likely to effectuate a positive patient outcome. Further research will add to the current knowledge base while laying the groundwork for new interventions.

What is your life like now? Loneliness and elderly individuals residing in nursing homes

Loneliness has been associated with cognitive deterioration, social isolation, hopelessness, and the inability to perform independent activities of daily living. Three factors have been found to increase levels of loneliness among elderly individuals residing in a nursing home: lack of intimate relationships, increased dependency, and loss. Nurses in long-term care facilities are in a position to directly intervene with elderly residents. Individualized interventions will allow the resident to have greater well being and greater quality of life.

Pain among the elderly: an action plan

Pain is the most frequently communicated nursing-sensitive patient outcome among the elderly. An effective action plan to decrease pain among the elderly should encompass both medically based interventions and psychosocial techniques. Nurses who are familiar with the latest information about pain and who are cognizant of and comfortable with their own views about pain are likely to bring about a positive patient outcome. Further research will add to the current knowledge base while laying the groundwork for new interventions.

Spirituality and the elderly: nursing implications with nursing home residents

Spiritual care is integral to quality nursing care for nursing home residents. Spirituality can be defined as dynamic principles developed throughout the lifespan that guide a person's view of the world; influence his or her interpretation of a higher power, hope, morals, loss, faith, love, and trust; and provide structure and meaning to everyday activities. Spiritually focused nursing interventions include silent witnessing, serving as a liaison, and active listening. Nursing interventions for spiritual care can be divided into four dynamic phases: self-comfort, assessment, intervention, and evaluation. Spiritual well-being helps residents' total well-being and inner peace.