Transient Effects of Sleep on Next-Day Pain and Fatigue in Older Adults With Symptomatic Osteoarthritis

Physical inactivity is the most important unhealthy lifestyle factor for pain severity in older adults with pain: A SHARE-based analysis of 27,528 cases from 28 countries

BACKGROUND

Limited knowledge exists on the association between lifestyle factors and pain severity in older adults.

OBJECTIVE

To assess the associations between unhealthy lifestyle variables and pain severity in the European population of older adults with pain.

DESIGN

Cross-sectional.

METHODS

Data were retrieved from the ninth wave of the Survey of Health, Ageing and Retirement in Europe (SHARE), a representative survey of individuals aged >50 years living in 27 European countries and Israel. Associations between lifestyle factors (sleep, smoking, diet and physical inactivity) and pain severity (mild, moderate, severe) were assessed using multivariable multinomial regression adjusted for age, sex, geographic region, education, history of chronic disease and mutually adjusted for each lifestyle.

RESULTS

27,528 cases were included (73.1 ± 9.76 years; 63.3% female). A significant association was observed between those who hardly ever or never engaged in activities that required a moderate level of energy and severe pain (OR: 4.35; 95% CI: 3.85 to 4.92). Sleep problems (OR: 1.83; 95% CI: 1.69 to 1.99), smoking (OR: 1.21; 95% CI: 1.13 to 1.34) and an inadequate diet (OR: 1.78: 95% CI: 1.22 to 2.61) were also significantly associated with severe pain, but with lower odds. Given the cross-sectional design, the bidirectionality of these relationships should be considered.

CONCLUSION

Physically inactive older adults were particularly more likely to experience severe pain, while other lifestyle factors were more weakly associated with pain. As these lifestyle factors are modifiable, the results may be useful in prioritising appropriate preventive measures to attenuate pain and ensure healthy ageing.

Unveiling the novel role of circadian rhythms in sepsis and septic shock: unexplored implications for chronotherapy

Circadian rhythms are critical to coordinating body processes to external environmental cues, such as light and feeding, to ensure efficiency and maintain optimal health. These rhythms are controlled by 'clock' transcription factors, such as Clock, Bmal1, Per1/2, Cry1/2, and Rev-erbs, which are present in almost every tissue. In modern society, disruptions to normal circadian rhythms are increasingly prevalent due to extended lighting, shift work, and long-distance travel. These disruptions misalign external cues to body processes and contribute to diseases such as obesity and non-alcoholic fatty liver disease. They also exacerbate pre-existing health issues, such as depression and inflammatory bowel disease. The normal inflammatory response to acute infection displays remarkable circadian rhythmicity in humans with increased inflammatory activity during the normal night or rest period. Severe bloodborne infections, exemplified in sepsis and the progression to septic shock, can not only disrupt the circadian rhythmicity of inflammatory processes but can be exacerbated by circadian misalignment. Examples of circadian disruptions during sepsis and septic shock include alteration or loss of hormonal rhythms controlling blood pressure and inflammation, white blood cell counts, and cytokine secretions. These changes to circadian rhythms hinder sepsis and septic shock recovery and also increase mortality. Chronotherapy and chronopharmacotherapy are promising approaches to resynchronise circadian rhythms or leverage circadian rhythms to optimise medication efficacy, respectively, and hold much potential in the treatment of sepsis and septic shock. Despite knowledge of how circadian rhythms change in these grave conditions, very little research has been undertaken on the use of these therapies in support of sepsis management. This review details the circadian disruptions associated with sepsis and septic shock, the influence they have on morbidity and mortality, and the potential clinical benefits of circadian-modulating therapies.

Day-to-day associations between pain intensity and sleep outcomes in an adult chronic musculoskeletal pain population: A systematic review

BACKGROUND

In individuals with chronic musculoskeletal pain, a reciprocal relationship between sleep and pain across short and long-term evaluations exists. Sleep influences pain levels, while the level of pain also impairs sleep. However, given the day-to-day variability of both sleep and pain intensity, assessing this relationship within a daily time frame should be considered.

OBJECTIVES

To systematically review the literature concerning the bidirectional day-to-day relationship between night-time sleep variables and day-time pain intensity in individuals with chronic musculoskeletal pain.

METHODS

A systematic search (final search on October 12, 2023) in four databases (PubMed, Web of Science, Embase, PsycInfo) identified eligible articles based on pre-defined criteria. Three independent reviewers executed data extraction and risk of bias assessment using the "Quality In Prognosis Studies" tool. The study findings were synthesized narratively.

RESULTS

Eleven articles (1014 study participants; 83 associations) were included. A bidirectional relationship between pain intensity and sleep was found. Nine articles indicated night-time sleep quality to be a more consistent predictor for next day pain intensity than vice versa.

CONCLUSION

Nonetheless the bidirectional day-to-day sleep-pain relationship in individuals with chronic musculoskeletal pain, results suggest that self-reported sleep quality has a stronger predictive value on pain intensity then vice versa.

The relationship between pain, sleep quality, and care dependency in older adults living in a long-term care facility

BACKGROUND

Due to the frequency of pain, sleep disorders and the complexity of their associated factors, the diagnosis of these disorders may be of great importance in identifying factors linked to care dependency in older people staying in long-term care facilities. The aim of the study was to investigate the relationship between pain, sleep quality, and care dependency in older adults living in a long-term care facility.

METHODS

The study was conducted among older people staying in a long-term care facility between October 2022 and September 2023. The study used a survey questionnaire including questions about demographic and social characteristics, clinical condition and the following scales: ADL, IADL, GSD-15, GPM-24, CDS, PSQI.

RESULTS

The analysis showed a statistically significant relationship between the deterioration of sleep quality by 1 unit and: an increase in the level of pain (B = 0.68; SE = 0.17; 95% CI [0.38; 1.10]), dependency in ADL (B = -0.09; SE = 0.04; 95% CI [-0.17; -0.02]), feeling depressed (B = 0.18; SE = 0.06; 95% CI [0 0.06, 0.31]) and care dependency (B = -0.78, SE = 0.24, 95% CI [-1.25, -0.31]). A statistically significant effect was noted between: pain level (B = -0.18; SE = 0.06; 95% CI [-0.30; -0.05], dependency in ADL (B = 1.98; SE = 0.35; 95% CI [1.28; 2.68]), instrumental activities of daily living (B = 1.86; SE = 0.28; 95% CI [1.30; 2.42]], feelings of depression (B = -0.96; SE = 0.17; 95% CI [-1.30; -0.62]) and care dependency.

CONCLUSIONS

The study is a valuable addition to research showing a strong link between pain, sleep quality and care dependency. The results support the need for a holistic approach in assessing pain, sleep quality, care dependency in older adults living in a long-term care facility.

Cognitive behavioral therapy for insomnia in people with chronic musculoskeletal pain. A systematic review and dose-response meta-analysis

The aims were (i) to determine the effects of Cognitive behavioral therapy for insomnia (CBT-I) on sleep disturbances, pain intensity and disability in patients with chronic musculoskeletal pain (CMP), and (ii) to determine the dose-response association between CBT-I dose (total minutes) and improvements in sleep disorders, pain intensity and disability in patients with CMP. A comprehensive search was conducted in PubMed/MEDLINE, Web of Science, CINAHL, and SCOPUS until December 17, 2023. Randomized clinical trials (RCTs) using CBT-I without co-interventions in people with CMP and sleep disorders were eligible. Two reviewers independently extracted data and assessed risk of bias and certainty of the evidence. A random effects meta-analysis was applied to determine the effects on the variables of interest. The dose-response association was assessed using a restricted cubic spline model. Eleven RCTs (n = 1801 participants) were included. We found a significant effect in favor of CBT-I for insomnia (SMD: -1.34; 95%CI: -2.12 to -0.56), with a peak effect size at 450 min of CBT-I (-1.65, 95%CI: -1.89 to -1.40). A non-significant effect was found for pain intensity. A meta-analysis of disability was not possible due to the lack of data. This review found benefits of CBT-I for insomnia compared to control interventions, with a large effect size. In addition, it was estimated that a 250-min dose of CBT-I had a large effect on reducing insomnia and that the peak effect was reached at 450 min. These novel findings may guide clinicians in optimizing the use of CBT-I in people with CMP and insomnia.

The Contribution of Sleep Quality and Psychological Factors to the Experience of Within-Day Pain Fluctuations Among Individuals With Temporomandibular Disorders

We assessed the impact of day-to-day sleep quality and psychological variables (catastrophizing, negative affect, and positive affect) to within-day pain fluctuations in 42 females with painful temporomandibular disorders (TMD) using electronic diaries. More specifically, we examined the contribution of these variables to the likelihood of experiencing pain exacerbations defined as 1) an increase of 20 points (or more) in pain intensity on a 0 to 100 visual analog scale from morning to evening, and/or 2) a transition from mild-to-moderate pain over the course of the day; and pain decreases defined as 3) a decrease of 20 points (or more) in pain intensity (visual analog scale) from morning to evening, and/or 4) a reduction from moderate-to-mild pain over the day. The results indicated significantly main effects of sleep on both pain exacerbation outcomes (both P's < .05), indicating that nights with better sleep quality were less likely to be followed by clinically meaningful pain exacerbations on the next day. The results also indicated that days characterized by higher levels of catastrophizing were associated with a greater likelihood of pain exacerbations on the same day (both P's < .05). Daily catastrophizing was the only variable significantly associated with within-day pain decrease indices (both P's < .05). None of the other variables were associated with these outcomes (all P's > .05). These results underscore the importance of addressing patients' sleep quality and psychological states in the management of painful TMD. PERSPECTIVE: These findings highlight the significance of sleep quality and pain catastrophizing in the experience of within-day pain fluctuations among individuals with TMD. Addressing these components through tailored interventions may help to alleviate the impact of pain fluctuations and enhance the overall well-being of TMD patients.

Examining the Association Between Objective Physical Activity and Momentary Pain: A Systematic Review of Studies Using Ambulatory Assessment

Chronic pain (CP) is a debilitating and increasingly common health condition that adversely impacts function, including physical activity (PA). Research using ambulatory assessment (AA) methods (eg, ecological momentary assessment, actigraphy) offers promise for elucidating the relationship between momentary pain and objective PA in CP populations. This study aimed to systematically review articles assessing the association between momentary pain and PA in adults with CP as measured using AA and to make recommendations for the measurement and study of this relationship. Five databases were systematically searched, and 13 unique records (N = 768) met the inclusion criteria. CP conditions included mixed/nonspecific CP (k = 3), low back pain (k = 2), fibromyalgia (k = 1), unspecified arthritis (k = 1), and hip/knee osteoarthritis (k = 6). The average age of participants across studies was 55.29 years, and the majority identified as women (60.68%) and White (83.16%). All studies measured objective PA via actigraphy, and momentary pain with either a diary/log or ratings on an actigraph. Studies varied in the quantification of PA (ie, activity counts, step count, moderate-vigorous PA), statistical method (ie, correlation, regression, multilevel modeling), and inclusion of moderators (eg, pain acceptance). Studies reported mixed results for the pain-PA relationship. This heterogeneity suggests that no summarizing conclusions can be drawn about the pain-PA relationship without further investigation into its complex nuances. More within-person and exploratory examinations that maximize the richness of AA data are needed. A greater understanding of this relationship can inform psychotherapeutic and behavioral recommendations to improve CP outcomes. PERSPECTIVE: This article presents a systematic review of the literature on the association between momentary pain and PA in adults with CP as measured using AA methods. A better understanding of this nuanced relationship could help elucidate areas for timely intervention and may inform clinical recommendations to improve CP outcomes. PROSPERO REGISTRATION NUMBER: CRD42023389913.

Bidirectional Links of Daily Sleep Quality and Duration With Pain and Self-rated Health in Older Adults' Daily Lives

BACKGROUND

Sleep and health perceptions, such as self-ratings of pain and health are closely linked. However, the temporal ordering of such associations is not well understood, and it remains unclear whether sleep quality and sleep duration show similar or differential associations with health perceptions.

METHODS

We used ecological momentary assessment data from 123 young-old (66-69 years, 47% women) and 47 old-old adults (84-90 years, 60% women). Across 7 consecutive days, participants reported their sleep quality and sleep duration each morning and rated their momentary pain and health 6 times per day. We applied dynamic structural equation models to examine bidirectional links of morning reports of sleep quality and duration with daily levels of self-rated pain and health.

RESULTS

In line with the hypotheses, results showed that when participants reported better sleep quality than what is typical for them, they reported less pain and better self-rated health on the day that followed. Longer sleep duration was not linked with subsequent pain or self-rated health. On days when people rated their health as better than usual, they reported better sleep quality but not longer sleep duration the following night. These associations were not moderated by age, gender, or chronic pain.

CONCLUSION

Findings suggest that in old age, sleep quality is more relevant for health perceptions than sleep duration. Associations between sleep quality and self-rated health seem to be bidirectional; daily pain was linked to prior but not subsequent sleep quality.

Experiences and Perceptions of Using Smartphone Ecological Momentary Assessment for Reporting Knee Osteoarthritis Pain and Symptoms

BACKGROUND

Knee osteoarthritis (OA) is a prevalent, painful, and disabling musculoskeletal condition. One method that could more accurately monitor the pain associated with knee OA is ecological momentary assessment (EMA) using a smartphone.

OBJECTIVES

The aim of this study was to explore participant experiences and perceptions of using smartphone EMA as a way of communicating knee OA pain and symptoms following participating in a 2-week smartphone EMA study.

MATERIALS AND METHODS

Using a maximum variation sampling method, participants were invited to share their thoughts and opinions in semistructured focus group interviews. Interviews were recorded and transcribed verbatim before thematic analysis using the general inductive approach.

RESULTS

A total of 20 participants participated in 6 focus groups. Three themes and 7 subthemes were identified from the data. Identified themes included: user experience of smartphone EMA, data quality of smartphone EMA, and practical aspects of smartphone EMA.

DISCUSSION

Overall, smartphone EMA was deemed as being an acceptable method for monitoring pain and symptoms associated with knee OA. These findings will assist researchers in designing future EMA studies alongside clinicians implementing smartphone EMA into practice.

PERSPECTIVE

This study highlights that smartphone EMA is an acceptable method for capturing pain-related symptoms and experiences of those expereiencing knee OA. Future EMA studies should ensure design features are considered that reduce missing data and limit the responder burden to improve data quality.

Role of Melatonin in Cancer: Effect on Clock Genes

The circadian clock is a regulatory system, with a periodicity of approximately 24 h, that generates rhythmic changes in many physiological processes. Increasing evidence links chronodisruption with aberrant functionality in clock gene expression, resulting in multiple diseases, including cancer. In this context, tumor cells have an altered circadian machinery compared to normal cells, which deregulates the cell cycle, repair mechanisms, energy metabolism and other processes. Melatonin is the main hormone produced by the pineal gland, whose production and secretion oscillates in accordance with the light:dark cycle. In addition, melatonin regulates the expression of clock genes, including those in cancer cells, which could play a key role in the numerous oncostatic effects of this hormone. This review aims to describe and clarify the role of clock genes in cancer, as well as the possible mechanisms of the action of melatonin through which it regulates the expression of the tumor's circadian machinery, in order to propose future anti-neoplastic clinical treatments.

Osteoarthritis is positively associated with self-reported sleep trouble in older adults

BACKGROUND

Osteoarthritis (OA) is a leading cause of disability in older adults. Most research has focused on minimizing pain and maximizing physical function so as to maintain patient mobility preceding joint arthroplasty. However, few studies have formally studied the relationship between OA and sleep trouble, although it is clinically recognized that OA may affect sleep.

METHODS

The study was based on the National Health and Nutrition Examination Survey (NHANES) database from 2011-2018. Participants were defined as adults aged 60 years or older with diagnoses of OA and self-reported sleep trouble. Multivariable regression analyses were applied to assess the association between OA and sleep trouble, adjusting for age, sex, body mass index, race/ethnicity, education level, marital status, income, depression level, etc. RESULTS: This study included 4154 participants, consisting of the control group (n = 2966) and the OA group (n = 1188). OA individuals were 2.11 (95% CI 1.79-2.47, p < 0.001) times more likely to have sleep trouble compared with those without OA. On subgroup analyses, there was lower odds ratio value of sleep trouble in men compared with women, and in the highest income group compared with the other income groups.

CONCLUSIONS

OA was positively associated with sleep trouble in older adults, with different odds ratio values among different subgroups. Our results suggest that older adults with OA should be aggressively screened for sleep problems.

Rhythm disturbance in osteoarthritis

Osteoarthritis (OA) is one of the main causes of disabilities among older people. To date, multiple disease-related molecular networks in OA have been identified, including abnormal mechanical loadings and local inflammation. These pathways have not, however, properly elucidated the mechanism of OA progression. Recently, sufficient evidence has suggested that rhythmic disturbances in the central nervous system (CNS) and local joint tissues affect the homeostasis of joint and can escalate pathological changes of OA. This is accompanied with an exacerbation of joint symptoms that interfere with the rhythm of CNS in reverse. Eventually, these processes aggravate OA progression. At present, the crosstalk between joint tissues and biological rhythm remains poorly understood. As such, the mechanisms of rhythm changes in joint tissues are worth study; in particular, research on the effect of rhythmic genes on metabolism and inflammation would facilitate the understanding of the natural rhythms of joint tissues and the OA pathology resulting from rhythm disturbance.

Within-day rhythms of pain and cognitive function in people with and without fibromyalgia: synchronous or syncopated?

ABSTRACT

Cognitive dysfunction is a common fibromyalgia (FM) symptom and can impact on the daily lives of those affected. We investigated whether within-day pain intensity ratings were associated with contemporaneous objective and subjective measures of cognitive function and whether within-day increases in pain intensity preceded increases in cognitive dysfunction or vice versa. Inclusion of a non-FM group allowed us to examine whether effects were specific to FM. Fifty people with FM and 50 non-FM controls provided 7 days of data. Cognitive tests (processing speed and working memory) and ecological momentary assessments (pain intensity and self-reported cognitive functioning) were conducted ×5/day. Three-level multilevel models examined contemporaneous and within-day 1-lag pain intensity-cognitive functioning associations. Interaction terms assessed possible moderating effects of FM status. Momentary increase in pain was associated with increased self-reported cognitive dysfunction, more strongly so for those with FM (B = 0.27, 95% confidence interval 0.22-0.32; non-FM B = 0.17, 95% confidence interval 0.10-0.23). For the FM group, higher pain was associated with longer processing speed; for the non-FM group, higher pain was associated with shorter processing speed. Pain increase did not precede change in subjective or objective cognitive function in the FM group, but reduction in working memory preceded increase in pain intensity. This finding warrants further research attention and, if replicated, could hold prognostic and/or therapeutic potential.

Daily Variation in Sleep Quality is Associated With Health-Related Quality of Life in People With Spinal Cord Injury

OBJECTIVE

Although sleep difficulties are common after spinal cord injury (SCI), little is known about how day-to-day fluctuations in sleep quality affects health-related quality of life (HRQOL) among these individuals. We examined the effect of sleep quality on same-day HRQOL using ecological momentary assessment methods over a 7-day period.

DESIGN

Repeated-measures study involving 7 days of home monitoring; participants completed HRQOL measures each night and ecological momentary assessment ratings 3 times throughout the day; multilevel models were used to analyze data.

SETTING

Two academic medical centers.

PARTICIPANTS

A total of 170 individuals with SCI (N=170).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Daily sleep quality was rated on a scale of 0 (worst) to 10 (best) each morning. Participants completed end-of-day diaries each night that included several HRQOL measures (Sleep Disturbance, Sleep-related Impairment, Fatigue, Cognitive Abilities, Pain Intensity, Pain Interference, Ability to Participate in Social Roles and Activities, Depression, Anxiety) and ecological momentary assessment ratings of HRQOL (pain, fatigue, subjective thinking) 3 times throughout each day.

RESULTS

Multilevel models indicated that fluctuations in sleep quality (as determined by end-of-day ratings) were significantly related to next-day ratings of HRQOL; sleep quality was related to other reports of sleep (Sleep Disturbance; Sleep-related Impairment; Fatigue) but not to other aspects of HRQOL. For ecological momentary assessment ratings, nights of poor sleep were related to worse pain, fatigue, and thinking. Generally, sleep quality showed consistent associations with fatigue and thinking across the day, but the association between sleep quality and these ecological momentary assessment ratings weakened over the course of the day.

CONCLUSIONS

Findings highlight the important association between sleep and HRQOL for people with SCI. Future work targeting sleep quality improvement may have positive downstream effects for improving HRQOL in people with SCI.

Fatigue in community-dwelling older adults: A review of definitions, measures, and related factors

Fatigue is a common age-related symptom among community-dwelling adults aged 65 years and older. Yet, a systematic approach has rarely been applied to review definitions, measures, related factors, and consequences of fatigue in this population. A scoping review was conducted in December 2020 to fill the gap, and 36 articles met the inclusion criteria. Definitions, albeit diverse, included at least one of the following attributes: an early indicator of disablement, subjective, a lack of energy, multidimensional, impaired daily activities, and temporal. A summary of fatigue measures used in this population was provided, including a brief overview, number of items, reliability, and validity. In general, different measures were used with considerable variability in the content. Additionally, most measures had limited information on test-retest reliability and validity. Fatigue-related factors mapped into biological, psychological, social, and behavioral factors. Fatigue consequences were primarily declines in physical and cognitive functions. (100-150 words).

A classification algorithm to predict chronic pain using both regression and machine learning - A stepwise approach

This secondary data analysis study aimed to (1) investigate the use of two sense-based parameters (movement and sleep hours) as predictors of chronic pain when controlling for patient demographics and depression, and (2) identify a classification model with accuracy in predicting chronic pain. Data collected by Oregon Health & Science University between March 2018 and December 2019 under the Collaborative Aging Research Using Technology Initiative were analyzed in two stages. Data were collected by sensor technologies and questionnaires from older adults living independently or with a partner in the community. In Stage 1, regression models were employed to determine unique sensor-based behavioral predictors of pain. These sensor-based parameters were used to create a classification model to predict the weekly recalled pain intensity and interference level using a deep neural network model, a machine learning approach, in Stage 2. Daily step count was a unique predictor for both pain intensity (75% Accuracy, F1 = 0.58) and pain interference (82% Accuracy, F1 = 0.59). The developed classification model performed well in this dataset with acceptable accuracy scores. This study demonstrated that machine learning technique can be used to identify the relationship between patients' pain and the risk factors.

Chronotherapy

The objective of chronotherapy is to optimize medical treatments taking into account the body's circadian rhythms. Chronotherapy is referred to and practiced in two different ways: (1) to alter the sleep-wake rhythms of patients to improve the sequels of several pathologies; (2) to take into account the circadian rhythms of patients to improve therapeutics. Even minor dysfunction of the biological clock can greatly affect sleep/wake physiology causing excessive diurnal somnolence, increase in sleep onset latency, phase delays or advances in sleep onset, frequent night awakenings, reduced sleep efficiency, delayed and shortened rapid eye movement sleep, or increased periodic leg movements. Chronotherapy aims to restore the proper circadian pattern of the sleep-wake cycle, through adequate sleep hygiene, timed light exposure, and the use of chronobiotic medications, such as melatonin, that affect the output phase of circadian rhythms, thus controlling the clock. Concerning the second use of chronotherapy, therapeutic outcomes as diverse as the survival after open-heart surgery or the efficacy and tolerance to chemotherapy vary according to the time of day. However, humans are heterogeneous concerning the timing of their internal clocks. Not only different chronotypes exist but also the endogenous human circadian period (τ) is not a stable trait as it depends on many internal and external factors. If any scheduled therapeutic intervention is going to be optimized, a tool is needed for simple diagnostic and objectively measurement of an individual's internal time at any given time. Methodologic advances like the use of single-sample gene expression and metabolomics are discussed.

Daily associations between sleep and pain in patients with chronic musculoskeletal pain

Patients with chronic pain commonly report sleep problems, and the evidence for a relationship between sleep disturbance and pain seems robust. The day-to-day associations between these constructs are less well studied, particularly with objective sleep measures such as actigraphy. Moreover, the concurrent presence of negative affective symptoms, as well as seasonality effects at extreme latitudes may complicate it further. Here, we studied 56 patients with chronic primary musculoskeletal pain conditions, contributing data in two separate 7-day data-collection periods during the summer and winter, respectively. The effect of self-reported sleep quality, and actigraphy measured sleep duration, efficiency and timing on next-day pain, as well as the effect of pain on the same sleep indices were estimated by generalised linear mixed regression models. The models were additionally adjusted for age, sex, education, data collection period, weekend, season and mental distress, with the latter two also specified as moderators. We observed a significant effect of pain as a predictor of next-night sleep quality (p = .003) and marginally of next-night sleep duration (p = .079). Conversely, sleep quality tentatively predicted next-day pain (p = .063). No other day-to-day associations were present. Mental distress was the strongest predictor of pain, but it did not modify the sleep-pain associations, nor did season. In conclusion pain, sleep quality and mental distress are closely related, underscoring the importance of encompassing this complexity in assessment and treatment of patients with chronic pain.

The relationship between restless sleep and symptoms of the knee: data from the Osteoarthritis Initiative

OBJECTIVE

To examine the associations between restless sleep and knee symptoms among individuals with radiographically confirmed KOA.

METHODS

Cross-sectional and longitudinal associations were examined using Osteoarthritis Initiative (OAI) data. Participants with radiographic KOA (n = 2517) were asked how often sleep was restless in the past week over the 4 years, and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) was used to measure knee symptoms. Adjusted β coefficients (aβ) and 95% confidence intervals (CI) were derived from generalized estimating equations (GEEs) models stratified by sex.

RESULTS

One in 7 participants reported ≥ 3 nights with restless sleep. Cross-sectional analyses indicated that restless sleep 5-7 nights was associated with worse symptoms (Women: pain: aβ 1.93, 95% CI 1.12-2.74, stiffness: aβ 0.57, 95% CI 0.19-0.94, physical function: aβ 5.68, 95% CI 3.09-8.27; Men: pain: aβ = 1.85, 95% CI 0.85-2.86; stiffness: aβ 0.63, 95% CI 0.15-1.12; physical function: aβ 5.89, 95% CI 2.68-9.09) compared with < 1 night. Longitudinal analyses confirmed that more nights with restless sleep were associated with worse pain (P trend = 0.01) and function (P trend = 0.04) in women and physical function in men (P trend = 0.04), although estimates did not meet thresholds for minimal clinically meaningful differences.

CONCLUSION

While the analysis of cross-sectional data supported the association between restless sleep and KOA symptoms, such relationships were not confirmed in more robust longitudinal analysis. Further research examining whether sleep quality, duration, or disorders is associated with worsening symptoms in persons with KOA is warranted. Key Points • The prevalence of frequent restless sleep among persons with knee OA is not uncommon. • There were linear trends between frequency of restless sleep and self-reported symptoms of the knee in cross-sectional analyses. • In the more robust longitudinal analysis, despite the statistically significant linear trends observed between frequency of restless sleep and symptoms (women: pain and physical function; men: function), none appeared to reach the a priori selected ranges for minimally clinically relevant differences.

A Biopsychosocial Model of Chronic Pain for Older Adults

Population

Comprehensive evaluation of chronic pain in older adults is multifaceted.

Objective and Methods

Research on chronic pain in older adults needs to be guided by sound conceptual models. The purpose of this paper is to describe an adaptation of the Biopsychosocial Model (BPS) of Chronic Pain for older adults. The extant literature was reviewed, and selected research findings that provide the empiric foundation for this adaptation of the BPS model of chronic pain are summarized. The paper concludes with a discussion of specific recommendations for how this adapted model can be used to guide future research.

Conclusions

This adaptation of the BPS model of chronic pain for older adults provides a comprehensive framework to guide future research in this vulnerable population.