Matthew Marler

Increased Light Exposure Consolidates Sleep and Strengthens Circadian Rhythms in Severe Alzheimer's Disease Patients

Sleep in the nursing home environment is extremely fragmented, possibly in part as a result of decreased light exposure. This study examined the effect of light on sleep and circadian activity rhythms in patients with probable or possible Alzheimers disease. Results showed that both morning and evening bright light resulted in more consolidated sleep at night, as measured with wrist actigraphy. Evening light also increased the quality of the circadian activity rhythm, as measured by a 5-parameter extended cosine model (amplitude, acrophase, nadir, slope of the curve, and relative width of the peak and trough). Increasing light exposure throughout the day and evening is likely to have the most beneficial effect on sleep and on circadian rhythms in patients with dementia. It would behoove nursing homes to consider increasing ambient light in multipurpose rooms where patients often spend much of their days.

Effect of Light Treatment on Sleep and Circadian Rhythms in Demented Nursing Home Patients

OBJECTIVES To determine whether fragmented sleep in nursing home patients would improve with increased exposure to bright light. DESIGN Randomized controlled trial. SETTING Two San Diego-area nursing homes. PARTICIPANTS Seventy-seven (58 women, 19 men) nursing home residents participated. Mean age +/- standard deviation was 85.7 +/- 7.3 (range 60-100) and mean Mini-Mental State Examination was 12.8 +/- 8.8 (range 0-30). INTERVENTIONS Participants were assigned to one of four treatments: evening bright light, morning bright light, daytime sleep restriction, or evening dim red light. MEASUREMENTS Improvement in nighttime sleep quality, daytime alertness, and circadian activity rhythm parameters. RESULTS There were no improvements in nighttime sleep or daytime alertness in any of the treatment groups. Morning bright light delayed the peak of the activity rhythm (acrophase) and increased the mean activity level (mesor). In addition, subjects in the morning bright light group had improved activity rhythmicity during the 10 days of treatment. CONCLUSION Increasing exposure to morning bright light delayed the acrophase of the activity rhythm and made the circadian rhythm more robust. These changes have the potential to be clinically beneficial because it may be easier to provide nursing care to patients whose circadian activity patterns are more socially acceptable.

Illumination levels in nursing home patients: effects on sleep and activity rhythms

Studies examining levels of illumination in adult populations have demonstrated that the level and amount of light exposure are lower in the elderly compared with younger adults, particularly in institutionalized patients with dementia. Although insufficient light exposure has been implied as a cause of sleep fragmentation, evidence for such a relationship is scant. Sixty‐six institutionalized elderly had their activity and light exposure monitored for a 3‐day period. Mean and median light levels, minutes spent over 1000 and over 2000 lux, percent sleep and wake, and number of naps were computed for daytime intervals, defined as 07.00–18.59. Percentages of sleep and wake, number of awakenings and mean duration of wake periods were computed for night‐time intervals, defined as 22.00–05.59. Mesor, amplitude and acrophase of activity and of light were determined by cosinor analysis. A mixed linear model was used to assess the effects of daytime Actillume measures on subsequent night‐time measures, and vice versa. Spearman correlations were computed, and multiple regression analyses were carried out with light variables and dementia level as predictors and sleep–wake and activity measures as dependent variables. The median light level was 54 lux and a median of only 10.5 min were spent over 1000 lux. Higher light levels predicted fewer night‐time awakenings, and severe dementia predicted more daytime sleep and lower mean activity. Increased bright light exposure predicted later activity acrophase. There was an association between the acrophases of light and of activity, with maximum illumination preceding peak activity. These results suggest that daytime light exposure has an impact on both night‐time sleep consolidation and timing of peak activity level.

Determinants of nasal CPAP compliance

BACKGROUND Obstructive sleep apnea is a prevalent condition with potentially serious medical and psychosocial consequences. Nasal continuous positive airway pressure (CPAP) is the treatment-of-choice and has been shown to reduce the frequency of nocturnal respiratory events, improve sleep architecture and decrease daytime sleepiness. Patient compliance with CPAP is disappointingly low. Previous studies examining determinants of CPAP compliance have limited the variables studied to patient (sociodemographic), disease status, and treatment variables, with few reliable determinants found. METHODS The purpose of the current study was to investigate the relationship between objectively measured CPAP compliance and variables from social cognitive theory (SCT) and the transtheoretical model (TM). Scales that measure variables from each model were developed and reliability evaluated. The relationship between the SCT and TM variables and compliance at 1-month post-CPAP-fitting was prospectively evaluated on 51 first-time CPAP users. SCT and TM variables were measured on the day of CPAP-fitting, at 1-week post-CPAP-fitting, and at 1-month post-CPAP-fitting. RESULTS SCT variables measured 1-week post-CPAP-fitting (R(2)=0.261, P=0.001) and TM variables measured 1-week post-CPAP-fitting (R(2)=0.17, P=0.002) accounted for a statistically significant amount of variance in objective CPAP compliance measured at 1 month. The decisional balance index (from TM) individually accounted for a significant amount of variance in objective CPAP compliance in the above analyses. CONCLUSIONS The ability of these new behavior change scales to predict CPAP compliance provides us with a new direction of research to better understand factors associated with compliance. The principal advantage of these theory-driven and empirically validated scales are that they measure modifiable factors that can provide the basis for sound interventions to improve CPAP compliance.

CIRCADIAN RHYTHMS OF AGITATION IN INSTITUTIONALIZED PATIENTS WITH ALZHEIMER'S DISEASE

Agitation is a common problem in institutionalized patientswith Alzheimers disease (AD). “Sundowning,” or agitationthat occurs primarily in the evening, is estimated to occur in 10—25%of nursing home patients. The current study examined circadian patterns ofagitation in 85 patients with AD living in nursing homes in the San Diego,California, area. Agitation was assessed using behavioral ratings collectedevery 15 minutes over 3 days, and activity and light exposure data were collectedcontinuously using Actillume recorders. A five-parameter extension of thetraditional cosine function was used to describe the circadian rhythms. Themean acrophase for agitation was 14:38, although there was considerable variabilityin the agitation rhythms displayed by the patients. Agitation rhythms weremore robust than activity rhythms. Surprisingly, only 2 patients (2.4%) were“sundowners.”In general, patients were exposed to very low levelsof illumination, with higher illumination during the night being associatedwith less robust agitation rhythms with higher rhythm minima (i.e., some agitationpresent throughout the day and night). Seasonality was examined; however,there were no consistent seasonal patterns found. This is the largest studyto date to examine agitation rhythms using behavioral observations over multiple24h periods. The results suggest that, although sundowning is uncommon, agitationappears to have a strong circadian component in most patients that is relatedto light exposure, sleep, and medication use. Further research into the understandingof agitation rhythms is needed to examine the potential effects of interventionstargeting sleep and circadian rhythms. (ChronobiologyInternational, 17(3), 405–418, 2000)

Continuous positive airway pressure reduces subjective daytime sleepiness in patients with mild to moderate alzheimer's disease with sleep disordered breathing

OBJECTIVES: Studies have reported that 33% to 70% of patients with Alzheimers disease (AD) have sleep‐disordered breathing (SDB). Continuous positive airway pressure (CPAP) treatment has been shown to reduce daytime sleepiness and improve health‐related quality of life in nondemented older people with SDB. The effect of therapeutic CPAP treatment on daytime sleepiness in patients with mild‐moderate AD with SDB was assessed.

Long-term follow-up of sleep disordered breathing in older adults.

OBJECTIVE The current study was designed to determine whether, with increasing age, sleep apnea improves, becomes worse, or stays the same. BACKGROUND There is a high prevalence of sleep disordered breathing (SDB) in older adults, but little is known about longitudinal changes. This study followed older adults to examine the natural history of SDB. METHODS Subjects were randomly selected community-dwelling elderly (n=427). A subset of subjects was studied approximately every 2 years over an 18-year period. Overnight sleep recordings and sleep questionnaires were completed at each time point. RESULTS Multiple linear regression showed that three variables were associated with change in respiratory disturbance index (RDI):body mass index (BMI) at initial visit (P=0.001), change in BMI (P=0.02), and a consistent self-report of high blood pressure (P=0.005). RDI increase was associated with BMI increase and presence of self-reported high blood pressure. CONCLUSIONS The changes in RDI that occurred were associated only with changes in BMI and were independent of age. This underscores the importance of managing weight for older adults, particularly those with hypertension.

Circadian Phase in Adults of Contrasting Ages

There is evidence that aging may impair phase‐shifting responses to light synchronizers, which could lead to disturbed or malsynchronized circadian rhythms. To explore this hypothesis, 62 elder participants (age, 58 to 84 years) and 25 young adults (age, 19 to 40 years) were studied, first with baseline 1‐wk wrist actigraphy at home and then by 72 h in‐laboratory study using an ultra‐short sleep‐wake cycle. Subjects were awake for 60 minutes in 50 lux followed by 30 minutes of darkness for sleep. Saliva samples were collected for melatonin, and urine samples were collected for aMT6s (a urinary metabolite of melatonin) and free cortisol every 90 minutes. Oral temperatures were also measured every 90 minutes. The timing of the circadian rhythms was not significantly more variable among the elders. The times of lights‐out and wake‐up at home and urinary free cortisol occurred earlier among elders, but the acrophases (cosinor analysis‐derived peak time) of the circadian rhythm of salivary melatonin, urinary aMT6s, and oral temperature were not significantly phase‐advanced among elders. The estimated duration of melatonin secretion was 9.9 h among elders and 8.4 h among young adults (p<0.025), though the estimated half‐life of blood melatonin was shorter among elders (p<0.025), and young adults had higher saliva melatonin and urinary aMT6s levels. In summary, there was no evidence for circadian desynchronization associated with aging, but there was evidence of some rearrangement of the internal phase‐angles among the studied circadian rhythms.

Pilot Randomized Trial of the Effect of Wireless Telemonitoring on Compliance and Treatment Efficacy in Obstructive Sleep Apnea

Background Obstructive sleep apnea (OSA) is a prevalent and serious medical condition characterized by repeated complete or partial obstructions of the upper airway during sleep and is prevalent in 2% to 4% of working middle-aged adults. Nasal continuous positive airway pressure (CPAP) is the gold-standard treatment for OSA. Because compliance rates with CPAP therapy are disappointingly low, effective interventions are needed to improve CPAP compliance among patients diagnosed with OSA. Objective The aim was to determine whether wireless telemonitoring of CPAP compliance and efficacy data, compared to usual clinical care, results in higher CPAP compliance and improved OSA outcomes. Methods 45 patients newly diagnosed with OSA were randomized to either telemonitored clinical care or usual clinical care and were followed for their first 2 months of treatment with CPAP therapy. CPAP therapists were not blinded to the participants’ treatment group. Results 20 participants in each group received the designated intervention. Patients randomized to telemonitored clinical care used CPAP an average of 4.1 ± 1.8 hours per night, while the usual clinical care patients averaged 2.8 ± 2.2 hours per night (P = .07). Telemonitored patients used CPAP on 78% ± 22% of the possible nights, while usual care patients used CPAP on 60% ± 32% of the nights (P = .07). No statistically significant differences between the groups were found on measures of CPAP efficacy, including measures of mask leak and the Apnea-Hypopnea Index. Patients in the telemonitored group rated their likelihood to continue using CPAP significantly higher than the patients in the usual care group. Patients in both groups were highly satisfied with the care they received and rated themselves as “not concerned” that their CPAP data were being wirelessly monitored. Conclusions Telemonitoring of CPAP compliance and efficacy data and rapid use of those data by the clinical sleep team to guide the collaborative (ie, patient and provider) management of CPAP treatment is as effective as usual care in improving compliance rates and outcomes in new CPAP users. This study was designed as a pilot—larger, well-powered studies are necessary to fully evaluate the clinical and economic efficacy of telemonitoring for this population.

The relationship between fatigue and light exposure during chemotherapy

BackgroundFatigue is one of the most common and distressing complaints among cancer patients, not only during radiation and chemotherapy, but also for months to years after the completion of treatment. Fatigue interferes with patients’ daily lives, reduces their quality of life, and is often a significant reason why patients discontinue treatment. We hypothesized that some of the fatigue may be related to disrupted circadian rhythms and low light exposure. The main objective of this study therefore was to investigate the association between fatigue and light exposure among patients with breast cancer.MethodsAs part of a larger, ongoing prospective study on fatigue, sleep, and circadian rhythms in patients with breast cancer, an analysis of 63 women newly diagnosed with stage I–IIIA breast cancer and scheduled to receive four cycles of adjuvant or neoadjuvant anthracycline-based chemotherapy was conducted. Data were collected before and during weeks 1, 2, and 3 of cycle 1 and cycle 4. Fatigue was assessed using the Short Form of Multidimensional Fatigue Symptom Inventory. Light exposure was recorded with a wrist actigraph.ResultsThere were significant correlations between fatigue levels and light exposure (r=−0.28 to −0.45) within both cycle 1 and cycle 4, such that higher levels of fatigue were associated with less light exposure. There were also significant correlations between changes in light exposure and changes in fatigue within the first 2 weeks of each cycle (r=−0.28 to −0.52).ConclusionsIncreased fatigue was significantly correlated with decreased light exposure among patients with breast cancer. Although the cause and effect of exacerbated fatigue and decreased light exposure cannot be confirmed by the current study, and lower light exposure may just in part be due to the fatigued patients spending less time outdoors in bright light, two hypotheses are proposed about the mechanisms by which light may alleviate the fatigue of patients with breast cancer. These results suggest the need for prospective intervention studies of light therapy for breast-cancer-related fatigue.