Emerging biobehavioral factors of fatigue in sickle cell disease

Preliminary data examining associations of fatigue subtypes with pain, pain interference, sleep quality, and affect across 14 days in adolescents with chronic musculoskeletal pain and pain-free controls

OBJECTIVE

This preliminary study analyzed existing data from a larger study to characterize fatigue subtypes (general, cognitive, and sleep-related) across 14 days in adolescents with chronic musculoskeletal (MSK) pain and pain-free controls. A secondary exploratory aim was to determine whether fatigue subtypes were associated with next-day pain intensity, pain interference, sleep quality, or positive or negative affect.

METHODS

Participants were 26 adolescents with chronic MSK pain and 26 pain-free controls matched on age and sex who completed a daily diary assessing fatigue subtypes, pain intensity, pain interference, sleep quality, and affect for 14 consecutive nights. Data were aggregated across all nights for between-group comparisons, and dynamic structural equation models were used to determine how fatigue subtypes were associated with pain, sleep, and affect from one day to the next.

RESULTS

Averaging across 14 days, participants in the MSK group reported greater total fatigue and fatigue subtypes than participants in the control group (all p's < .001). Averaging across days, participants in the MSK group reported higher general fatigue than cognitive (p = .03) or sleep-related fatigue (p = .053). In the exploratory within-person analysis, previous day's cognitive fatigue (-0.10, p < .01) and general fatigue (-0.08, p < .01) were associated with worse next-day sleep quality in the MSK pain group. In the control group, cognitive fatigue was associated with greater next-day pain intensity (.04; p < .01) but lower next day pain interference (-0.03; p < .001).

CONCLUSIONS

Results preliminarily suggest fatigue subtypes are prevalent and impactful in adolescents with chronic MSK pain. Future replication of results is needed.

Evaluating fatigue and excessive daytime sleepiness: a comparative analysis of prevalence and correlating factors in interstitial lung disease patients and healthy controls

INTRODUCTION

Fatigue and excessive daytime sleepiness (EDS) frequently affect interstitial lung disease (ILD) patients, while studies are limited. The study aims to determine the prevalence and contributing factors of fatigue and EDS in ILD patients.

METHODS

This was a cross-sectional study. Consecutive patients diagnosed with ILD at the Second Xiangya Hospital of Central South University were recruited, and healthy volunteers were recruited as controls. Fatigue Assessment Scale and Epworth Sleepiness Scale scores were the basis for judging fatigue and EDS. The prevalence of fatigue and EDS between ILD patients and healthy volunteers were compared, and the differences in clinical characteristics between ILD patients with and without fatigue/EDS were analyzed. Binary logistic regression was used to analyze the correlation factors of fatigue and EDS.

RESULTS

In this study, 92 healthy volunteers and 108 ILD patients were recruited. The prevalence of fatigue and EDS was higher in ILD patients than in healthy volunteers (40.7% vs 9.8%, 35.2% vs 14.1%). ILD patients with fatigue showed significantly worse pulmonary diffusion function and exercise tolerance, alongside reduced quality of life, and increased instances of EDS, anxiety, and depression. Patients with EDS were older than non-EDS patients (68.5 vs 61.5 years; p = 0.038) and had a higher prevalence of fatigue and depression, along with decreased quality of life. Multivariable logistic regression identified chest pain/oppression and diminished exercise capacity as factors linked to fatigue, and age over 60 years and diminished exercise capacity as factors associated with EDS.

CONCLUSION

ILD patients experience a higher prevalence and more severe impact of fatigue and EDS than healthy individuals, with associated factors including chest pain, diminished exercise capacity, and age. Pulmonary rehabilitation and evaluation and intervention of factors associated with fatigue and EDS such as pain, and diminished exercise capacity in ILD patients may help to improve the quality of life.

Late effects of hemopoietic stem cell transplant for sickle cell disease: monitoring and management

INTRODUCTION

Allogeneic hemopoietic stem cell transplantation (HSCT) is a curative therapy for sickle cell disease (SCD). Exposure to both SCD and HSCT conditioning regimens is associated with late health effects.

AREAS COVERED

This review addresses post-HSCT outcomes and late health effects among individuals with SCD exposed to allogeneic HSCT regimens, summarizes recommendations for long-term care, and identifies future survivorship research needs.

EXPERT OPINION

Individuals with SCD exposed to HSCT and gene therapy require multidisciplinary care to monitor late health effects. To optimize care, multi-disciplinary clinics that include experts in late effects of HSCT exposure, SCD, complex chronic pain, mental health, and social work are needed. Research defining the late effects of exposure is needed to inform patient management and build clinical care infrastructure.

Sickle Cell Health Awareness, Perspectives, and Experiences (SHAPE) survey: Perspectives of adolescent and adult patients, caregivers, and healthcare professionals on the burden of sickle cell disease

OBJECTIVES

Sickle cell disease (SCD) is an inherited disorder that causes lifelong complications, substantially impacting the physical and emotional well-being of patients and their caregivers. Studies investigating the effects of SCD on quality of life (QOL) are often limited to individual countries, lack SCD-specific QOL questionnaires, and exclude the caregiver experience. The SHAPE survey aimed to broaden the understanding of the global burden of SCD on patients and their caregivers and to capture the viewpoint of healthcare providers (HCPs).

METHODS

A total of 919 patients, 207 caregivers, and 219 HCPs from 10, 9, and 8 countries, respectively, answered a series of closed-ended questions about their experiences with SCD.

RESULTS

The symptoms most frequently reported by patients were fatigue/tiredness (84%) and pain/vaso-occlusive crises (71%). Patients' fatigue/tiredness had one of the greatest impacts on both patients' and caregivers' QOL. On average, patients and caregivers reported missing 7.5 days and 5.0 days per month, respectively, of school or work. HCPs reported a need for effective tools to treat fatigue/tiredness and a desire for more support to educate patients on long-term SCD-related health risks.

CONCLUSIONS

The multifaceted challenges identified using the SHAPE survey highlight the global need to improve both patient and caregiver QOL.

Psychiatric comorbidities in adults with sickle cell disease: A narrative review

Although descriptions of quality of life and patient reports of mood in sickle cell disease (SCD) have become more common in the literature, less is known about psychiatric illness prevalence, presentation, and treatment, particularly for adults. We provide a narrative review of what is known about common and debilitating psychiatric conditions such as depression, anxiety, and cognitive impairment, specifically for adults with SCD. We discuss the limitations of the current evidence, make provisional recommendations, and identify opportunities for research and improved care.

Illness Intrusiveness in Adults with Sickle Cell Disease: The Role of Fatigue

Chronic illness experiences often interfere with daily functioning (a concept known as illness intrusiveness) and health-related quality of life (HRQoL). However, less is known about the role of specific symptoms in predicting illness intrusiveness in sickle cell disease (SCD). This exploratory study examined associations between common SCD-related symptoms (i.e., pain, fatigue, depression, and anxiety), illness intrusiveness, and HRQoL among adults with SCD (n = 60). Illness intrusiveness significantly correlated with fatigue severity (r = .39, p = .002), depression severity (r = .45, p < .001), anxiety severity (r = .41, p = .001), physical HRQoL (r = - .53, p < .001), and mental HRQoL (r = - .44, p < .001). Multiple regression revealed a significant overall model, (R2 = .28, F(4, 55) = 5.21, p = .001), with fatigue, but not pain, depression, or anxiety, significantly predicting illness intrusiveness (β = .29, p = .036). Results suggest that fatigue may be a primary factor contributing to illness intrusiveness-a determinant of HRQoL-in individuals with SCD. Given the limited sample size, larger confirmatory studies are warranted.

Psychosocial challenges of persons with sickle cell anemia: A narrative review

Sickle cell anemia (SCA) is a severe form of sickle cell disease that primarily affects black populations and individuals in tropical countries. This condition causes significant morbidity and mortality and leads to a range of psychosocial challenges. A preliminary search was conducted on Ovid Medline and public databases with a combination of Medical Subject Headings keywords, resulting in 368 articles. The articles were screened based on the selection criteria in a nonsystematic method by 3 researchers, and a narrative synthesis was done to analyze extracted data from selected peer-reviewed article. Mental disorders, sleep disturbances, interpersonal relationship challenges, stigmatization, and workplace discrimination were identified as significant contributors to the psychosocial distress experienced by individuals with SCA and their families. Depression and anxiety were prevalent among individuals with SCA, leading to poor treatment adherence, increased pain, and disruptions in various aspects of life. Sleep disturbances, including sleep-disordered breathing and sleepwalking, were also identified as significant contributors to poor sleep quality in SCA patients. Families of individuals with SCA also face challenges, including psychological stress, financial strain, and social disruption. Stigmatization is common, leading to misconceptions and discrimination. Workplace discrimination is prevalent, with a high unemployment rate among adult SCA patients. Comprehensive care is crucial to address these psychosocial issues. Early identification and intervention, comprehensive support programs, patient and family education, enhanced pain management strategies, and integration of mental health into clinical care are recommended. School-based support, research and advocacy, and community support groups are also important. By addressing these challenges through comprehensive care and support, healthcare professionals, policymakers, and society can reduce psychosocial distress and improve the lives of individuals with SCA.

Fatigue, Stress Appraisal, and Emotional Functioning Among Youth With Sickle Cell Disease: A Daily Diary Study

OBJECTIVE

The aim of this study was to assess how fatigue is related to mood among youth with sickle cell disease (SCD) by evaluating if the cognitive appraisal of stress moderates the impact of fatigue on emotional functioning consistent with the Risk-and-Resistance Model of Chronic Illness.

METHODS

Daily diaries assessing fatigue (Numerical Rating Scale), pain intensity (Numerical Rating Scale), mood (Positive and Negative Affect Schedule for Children), and cognitive appraisal of stress (Stress Appraisal Measure for Adolescents) were collected from 25 youth with SCD (ages 11-18 years) for 8 consecutive weeks resulting in 644 daily diaries for analyses.

RESULTS

When measured concurrently, higher fatigue was associated with higher negative mood controlling for pain and prior-night sleep quality. Fatigue predicted next-day negative mood through its interaction with primary and secondary appraisal of stress, consistent with stress appraisal as a protective factor. A similar pattern was observed for pain, which, like fatigue, is a common SCD-related stressor.

CONCLUSION

Fatigue and negative mood are inter-related when concurrently assessed, but their temporal association in SCD suggests that mood changes are not an inevitable sequalae of increased fatigue; fatigue influenced subsequent levels of negative mood, but only in the presence of less adaptive cognitions about stress; specifically, a higher perceived threat from stress and a lower belief in the ability to manage stress. The results suggest specific cognitive targets for reducing the negative impact of fatigue on mood in SCD.

Sleep and fatigue among youth with sickle cell disease: A daily diary study

Youth with sickle cell disease (SCD) experience disease effects including vaso-occlusive pain crises, poor sleep quality, and fatigue. The present study examines how sleep quality and pain medications impact fatigue in youth with SCD. Daily diaries assessing pain, fatigue, sleep quality, mood, and use of pain medications from 25 youth with SCD ages 11 to 18 years were collected for eight consecutive weeks. Poor sleep quality predicted increases in next-day fatigue levels while controlling for pain and mood. Sleep quality did not moderate the existing temporal relationship between pain and next-day fatigue established by Reinman et al. (2019) as predicted. Non-opioid medications affected ratings of next-day fatigue but opioid medications did not. Sleep quality appears to play an important role in predicting next-day fatigue levels and may be an important target for intervention. Pain medication use did not substantially contribute to prospective fatigue levels among youth, but requires further study.

Prevalence of comorbidities associated with sickle cell disease among non-elderly individuals with commercial insurance-A retrospective cohort study

Sickle cell disease (SCD) is a severe monogenic disease associated with high morbidity and mortality and a disproportionate burden on Black communities. Few population-based studies have examined the prevalence of comorbidities among persons with SCD. We estimated the prevalence of comorbidities experienced by individuals with SCD enrolled in employer-based health insurance plans in the US over their non-elderly lifetimes (0-64 years of age) with a retrospective cohort design using Truven Health MarketScan commercial claims data from 2007-2018. ICD-9/10 codes were used to identify individuals with SCD using a previously published algorithm. For this cohort, comorbidities associated with SCD were identified across 3 age categories (<18, 18-45, 46-64 years-old), based on the CMS Chronic Comorbidities Warehouse or SCD-specific diagnosis codes, when applicable. The total number of SCD patients available for analysis in each age category was 7,502 (<18 years), 10,183 (18-45 years) and 4,459 (46-64 years). Across all ages, vaso-occlusive pain, infections (non-specific), and fever were the most common comorbidities. Vaso-occlusive pain and infection were the most prevalent conditions for persons age <18- and 18-45-year-olds, while in the 46-54-year-old age group, infection and cardiovascular including pulmonary hypertension were most prevalent. Compared to persons <18 years old, the prevalence of vaso-occlusive pain, fever, and acute chest syndrome claims declined in older populations. The comorbidity burden of SCD is significant across all age groups. SCD patients experience comorbidities of age such as chronic pain, cardio-vascular conditions including pulmonary hypertension and renal disease at far higher rates than the general population. Novel disease modifying therapies in development have the potential to significantly reduce the comorbidity burden of SCD.

Sickle cell disease chronic joint pain: Clinical assessment based on maladaptive central nervous system plasticity

Chronic joint pain (CJP) is among the significant musculoskeletal comorbidities in sickle cell disease (SCD) individuals. However, many healthcare professionals have difficulties in understanding and evaluating it. In addition, most musculoskeletal evaluation procedures do not consider central nervous system (CNS) plasticity associated with CJP, which is frequently maladaptive. This review study highlights the potential mechanisms of CNS maladaptive plasticity related to CJP in SCD and proposes reliable instruments and methods for musculoskeletal assessment adapted to those patients. A review was carried out in the PubMed and SciELO databases, searching for information that could help in the understanding of the mechanisms of CNS maladaptive plasticity related to pain in SCD and that presented assessment instruments/methods that could be used in the clinical setting by healthcare professionals who manage chronic pain in SCD individuals. Some maladaptive CNS plasticity mechanisms seem important in CJP, including the impairment of pain endogenous control systems, central sensitization, motor cortex reorganization, motor control modification, and arthrogenic muscle inhibition. Understanding the link between maladaptive CNS plasticity and CJP mechanisms and its assessment through accurate instruments and methods may help healthcare professionals to increase the quality of treatment offered to SCD patients.

Research knowledge transfer to improve the care and support of adolescents with sickle cell disease in Ghana

INTRODUCTION

Effective transfer of research findings to key knowledge users, particularly in low- and middle-income countries, is not always achieved, despite being a shared priority among researchers, funders, healthcare and community stakeholders and decision-makers. A constructivist grounded theory study conducted in 2015-2019 in Ghana that explored sickle cell-related fatigue in adolescence resulted in numerous implications for practice and policy. Peer-reviewed funding was obtained to support disseminating these findings to relevant stakeholders.

METHODS

Key steps in implementing this study dissemination project included: (1) identifying and attracting target stakeholders from healthcare and community organizations; (2) tailoring tools for communication of research findings for the stakeholder groups and (3) designing interactive workshops to facilitate knowledge sharing and uptake.

FINDING

Despite the COVID-19 pandemic, 50 healthcare and community stakeholders participated in the dissemination workshops. The dissemination activities contributed new layers of understanding to the original research findings through discussions. Through the workshops, participants identified culturally valuable and actionable recommendations that they could take forward to improve care and support for young people with sickle cell disease in Ghana. A follow-up 6 months post the workshops indicated some positive knowledge usage and benefits.

CONCLUSION

This dissemination project provided a unique opportunity for researchers and stakeholders to share in the interpretation of research findings and to strategically plan recommendations to improve SCD-focused care and support for young people in Ghana. Further research dissemination should continue to be grounded in locally generated knowledge, include systematic, long-term evaluation of dissemination outcomes and be adequately financed.

PATIENT AND PUBLIC CONTRIBUTION

Public involvement in this study was critical to the research dissemination project. The Sickle Cell Association of Ghana (Kumasi chapter) actively supported the project's development, organization and facilitation. Parent members of the Association, the Association's executive members and volunteers, and the health professionals involved in sickle cell care at the Komfo Anokye Teaching Hospital participated in the project workshops. They contributed to the knowledge transfer and uptake.

Academic Performance of Children With Sickle Cell Disease in the United States: A Meta-Analysis

Background: Students with sickle cell disease are at risk for poor academic performance due to the combined and/or interactive effects of environmental, psychosocial, and disease-specific factors. Poor academic performance has significant social and health consequences. Objective: To study academic achievement and attainment in children with sickle cell disease in the United States. Design: Medline, Embase, SCOPUS, CINAHL, ERIC, and PsycINFO were searched for peer-reviewed articles. Studies of children (ages 5-18) diagnosed with sickle cell disease of any genotype reporting academic achievement (standardized tests of reading, math, and spelling) or attainment (grade retention or special education) outcomes were included. Outcomes were analyzed using a random effects model. Achievement scores were compared to within study controls or normative expectations. Prevalence of grade retention and special education services were compared to national (United States) estimates for Black students. Age at assessment and overall IQ were evaluated separately for association with reading and mathematics scores. Subgroup analyses of reading and math scores were analyzed by cerebral infarct status (no cerebrovascular accident, silent infarct, stroke). Results: There were 44 eligible studies. Students with sickle cell disease scored 0.70, 0.87, and 0.80 (p < 0.001) SD below normative expectations on measures of reading, mathematics, and spelling, respectively. Compared to unaffected sibling and/or healthy controls (k = 8, n = 508), reading and math scores were 0.40 (p = 0.017) and 0.36 (p = 0.033) SD below expectations. Grade retention was approximately 10 times higher in students with sickle cell disease than Black students nationally. Intellectual functioning explained 97.3 and 85.8% of the variance in reading and mathematics performance, respectively (p < 0.001). Subgroup analyses revealed significant differences in reading (p = 0.034) and mathematics (p < 0.001) based on infarct status, with lower performance associated with presence of a silent infarct or stroke. Conclusion: Students with sickle cell disease demonstrate notable academic difficulties and are at high risk for grade retainment. Development of academic interventions and increased access to school support services are needed for this vulnerable population. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020179062.

Impact of sickle cell disease on patients' daily lives, symptoms reported, and disease management strategies: Results from the international Sickle Cell World Assessment Survey (SWAY)

Sickle cell disease (SCD) is a genetic disorder, characterized by hemolytic anemia and vaso‐occlusive crises (VOCs). Data on the global SCD impact on quality of life (QoL) from the patient viewpoint are limited. The international Sickle Cell World Assessment Survey (SWAY) aimed to provide insights into patient‐reported impact of SCD on QoL. This cross‐sectional survey of SCD patients enrolled by healthcare professionals and advocacy groups assessed disease impact on daily life, education and work, symptoms, treatment goals, and disease management. Opinions were captured using a Likert scale of 1‐7 for some questions; 5‐7 indicated “high severity/impact.” Two thousand one hundred and forty five patients (mean age 24.7 years [standard deviation (SD) = 13.1], 39% ≤18 years, 52% female) were surveyed from 16 countries (six geographical regions). A substantial proportion of patients reported that SCD caused a high negative impact on emotions (60%) and school achievement (51%) and a reduction in work hours (53%). A mean of 5.3 VOCs (SD = 6.8) was reported over the 12 months prior to survey (median 3.0 [interquartile range 2.0‐6.0]); 24% were managed at home and 76% required healthcare services. Other than VOCs, fatigue was the most commonly reported symptom in the month before survey (65%), graded “high severity” by 67% of patients. Depression and anxiety were reported by 39% and 38% of patients, respectively. The most common patient treatment goal was improving QoL (55%). Findings from SWAY reaffirm that SCD confers a significant burden on patients, epitomized by the high impact on patientsʼ QoL and emotional wellbeing, and the high prevalence of self‐reported VOCs and other symptoms.

Voxelotor: alteration of sickle cell disease pathophysiology by a first-in-class polymerization inhibitor

Sickle cell disease, despite its recognition as a severely debilitating genetic condition affecting hundreds of thousands of neonates throughout the world each year, was not a target of pharmaceutical research focus for most of its 100-year existence in the medical consciousness. This has changed in recent years as many novel therapeutics are currently under investigation, with three new disease-modifying drugs achieving FDA approval in the last 4 years. One of these drugs, voxelotor, is especially encouraging as an inhibitor of sickling for its ability to safely improve the chronic hemolytic anemia of sickle cell disease. This was demonstrated during all clinical phases of investigation by an average improvement in hemoglobin of greater than 1 g/dL, as well as statistically significant improvements in established markers of hemolysis. While anemia itself represents a potential cause of morbidity, it is more importantly a marker of the hemolysis known to cause the long-term vascular and organ damage that makes sickle cell disease so debilitating and frequently fatal early in life. Given the recency of the approval, there has not been sufficient long-term follow-up to demonstrate improvement in the chronic sequelae of sickle cell disease as a result of voxelotor-induced improvements in hemolytic anemia. There is hope, however, based on the experience with hydroxyurea improving morbidity and mortality via reductions in sickling and improved rheology, that voxelotor may have similar long-term benefits by positively manipulating the kinetics of hemoglobin polymerization. This review aims to summarize the targeted pathobiology of sickle cell disease, the mechanism of action of voxelotor, and the safety and efficacy data from preclinical to late clinical stage investigations of this long-awaited medication, in the hopes of better informing the decision-making process behind prescribing or not prescribing it for patients in need of intervention.

Factors associated with fatigue in hip and/or knee osteoarthritis: a systematic review and best evidence synthesis

Objective

The aim was systematically to identify and evaluate factors related to fatigue in individuals with hip and/or knee OA.

Methods

A systematic literature search was conducted using AMED, CINAHL, MEDLINE, ProQuest and Web of Science Core Collections databases. Inclusion criteria comprised cross-sectional, case–control or longitudinal studies on patients with a diagnosis of hip and/or knee OA that included self-reported fatigue measures. Study quality was assessed using the National Heart, Lung and Blood Institute quality appraisal tool, and factors were synthesized within a bio-behavioural framework. Study designs and quality were combined to determine current evidence levels using best evidence synthesis grading. The full review protocol is available from PROSPERO (PROSPERO 2019: CRD42019138571).

Results

Twenty-four studies were included, of which 19 were high, 4 moderate and 1 low quality. There was strong evidence of an association between poor self-reported physical function and high depressive symptoms with higher fatigue. Moderate evidence of an association was found between severe pain, high numbers of co-morbidities and low physical activity levels with higher fatigue. There was moderate or limited evidence of no association between most sociodemographic factors and radiographic OA severity with fatigue.

Conclusion

Targets for fatigue management might include improving physical function, reducing depressive symptoms, pain and co-morbidities, and increasing physical activity levels. There is a need for more rigorous longitudinal studies to understand the causal effect of fatigue determinants within the hip and knee OA populations.

Developmental Profile of Sleep and Its Potential Impact on Daytime Functioning from Childhood to Adulthood in Sickle Cell Anaemia

Young individuals with sickle cell anaemia (SCA) experience sleep disturbances and often experience daytime tiredness, which in turn may impact on their daytime functioning and academic attainment, but there are few longitudinal data.

METHODS

Data on sleep habits and behaviour were taken on the same day as an in-hospital polysomnography. This study assesses the developmental sleep profiles of children and young adults aged 4-23 years old with SCA. We examined retrospective polysomnography (PSG) and questionnaire data.

RESULTS

A total of 256 children with a median age of 10.67 years (130 male) were recruited and 179 returned for PSG 1.80-6.72 years later. Later bedtimes and a decrease in total sleep time (TST) were observed. Sleep disturbances, e.g., parasomnias and night waking, were highest in preschool children and young adults at their first visit. Participants with lower sleep quality, more movement during the night and increased night waking experienced daytime sleepiness, potentially an indicator of lower daytime functioning. Factors influencing sleep quantity included age, hydroxyurea prescription, mean overnight oxygen saturation, sleep onset latency, periodic limb movement, socioeconomic status and night waking.

CONCLUSION

Sleep serves an important role for daytime functioning in SCA; hence, quantitative (i.e., PSG for clinical symptoms, e.g., sleep-disordered breathing, nocturnal limb movement) and qualitative (i.e., questionnaires for habitual sleep behaviour) assessments of sleep should be mutually considered to guide interventions.

Sleep Moderating the Relationship Between Pain and Health Care Use in Youth With Sickle Cell Disease

OBJECTIVES

The purpose of the current study was to investigate the influence of sleep on the relationship between pain and health care use (HCU) in youth with sickle cell disease (SCD). It was hypothesized that poor sleep would be related to higher HCU and would strengthen the relationship between high pain frequency and more HCU among youth with SCD.

MATERIALS AND METHODS

Ninety-six youth with SCD (aged 8 to 17 y) and their guardians were recruited from 3 regional pediatric SCD clinics. Guardians reported on the youth's pain frequency and HCU using the Structured Pain Interview for parents, and youth wore a sleep actigraph for up to 2 weeks to assess sleep duration and sleep efficiency. A series of regression models were calculated with the following outcomes: emergency department visits, hospitalizations, and health care provider contacts.

RESULTS

Inconsistent with hypotheses, poor sleep was not directly related to HCU. Also, higher sleep duration appeared to strengthen the relationship between high pain frequency and more emergency department visits.

CONCLUSIONS

Findings suggest that good sleep may serve as a protective factor for better matching pain to HCU. Results should be interpreted in the context of study limitations. Research is needed to investigate possible mechanisms linking sleep duration to HCU in response to pain and to ascertain if sleep patterns influence the relationship between pain and other functional outcomes in youth with SCD. Clinically, these findings support the need to acknowledge and address the role that sleep plays in responding to SCD pain in pediatric populations.

How Sickle Cell Disease Impairs Skeletal Muscle Function: Implications in Daily Life

Sickle cell disease (SCD) is the most frequent life-threatening genetic hemoglobinopathy in the world and occurs due to the synthesis of abnormal hemoglobin S (HbS). hemoglobin S-containing red blood cells (RBC) are fragile, leading to hemolysis and anemia, and adhere to the endothelium, leading to hemorheological and hemodynamical disturbances. In its deoxygenated form, HbS may polymerize, leading to sickling of red blood cells and potentially to vasoocclusive crises. Recent findings observed that SCD patients demonstrate significant skeletal muscle remodeling and display reduced muscle functional capacities, contributing to exercise intolerance and poor quality of life. Although acute high-intensity exercise is not recommended for SCD patients because it may increase the risk of sickling, regular moderate-intensity physical activity could have beneficial effects on skeletal muscle and more generally on the well-being of SCD patients. This article reviews the literature regarding the impact of the disease on muscular tissue characteristics and function, as well as the corresponding implications for SCD patients' quality of life.

Investigating the Sleep-Pain Relationship in Youth with Sickle Cell Utilizing mHealth Technology

OBJECTIVES

The current study utilized mHealth technologies that were objective (e.g., sleep actigraphy and pulse oximetry) and time-sensitive (e.g., ecological momentary assessments [EMAs]) to characterize sleep in youth with sickle cell disease (SCD) and investigate the relationships between sleep variables and pain. It also investigated the influence of age on sleep and the sleep-pain relationship.

METHODS

Eighty-eight youth with SCD (aged 8-17 years) were recruited from three regional pediatric SCD clinics. Youth completed twice daily EMAs for up to 4 weeks to assess nighttime subjective sleep quality and daily pain. They also wore a sleep actigraph for 2 weeks to assess sleep duration, sleep efficiency, and sleep latency, and a wrist-worn pulse oximeter for two nights to assess whether they had sleep apnea. Multilevel models were calculated predicting daily SCD pain using the sleep variables, age, and the interaction between age and the sleep variables.

RESULTS

None of the sleep variables were related to one another. Poor subjective sleep quality during the night was related to high pain severity the next day, and high pain was related to poor subjective sleep quality that night. Older age was associated with poorer subjective sleep quality, shorter duration of nighttime sleep, and high sleep latency. Also, findings indicated that as age increased, the strength of the relationship between poor continuous subjective sleep quality and high pain severity increased.

CONCLUSIONS

Future research is needed to examine possible mechanisms connecting subjective sleep quality to high pain.

A review and synthesis of correlates of fatigue in osteoarthritis

Fatigue affects nearly half of all adults with osteoarthritis. Affected individuals report difficulty with daily functioning, requiring more time and rest during activities, feeling easily exhausted, and having to give up on social and volunteer activities known to improve quality of life. Because its etiology is poorly understood, clinical practice guidelines are unable to address management of fatigue in osteoarthritis. Elucidating a mechanism of osteoarthritis fatigue is a high priority, but few studies have identified key factors associated with fatigue in osteoarthritis. Thus, the purpose of this narrative literature review is to present the current evidence of known and potential correlates of fatigue in osteoarthritis, and synthesize our findings into a conceptual framework. The overarching goal of this work is to provide insight into areas of needed research and guide future work toward mechanistic insight of osteoarthritis fatigue. This knowledge could lead to novel nursing interventions for prevention, management, and treatment of fatigue among adults with osteoarthritis.

AAAPT Diagnostic Criteria for Acute Sickle Cell Disease Pain

Acute pain episodes are the most common complication in patients with sickle cell disease (SCD). Classically attributed to vaso-occlusion, recent insights suggest that chronic pain may also contribute to the pathogenesis of acute pain episodes, which adds complexity to their diagnosis and management. A taxonomy, or classification system, for acute pain in patients with SCD would aid research efforts and enhance clinical care. To meet this need, the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks public-private partnership with the U.S. Food and Drug Administration, the American Pain Society, and the American Academy of Pain Medicine formed the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks-American Pain Society-American Academy of Pain Medicine Pain Taxonomy initiative. One of the goals of this initiative was to develop taxonomies for acute pain disorders, including SCD. To accomplish this, a working group of experts in SCD and pain was convened. Based on available literature and expert opinion, the working group used a 5-dimenional structure (diagnostic criteria, common features, modulating factors, impact/functional consequences, and putative mechanisms) to develop an acute pain taxonomy that is specific to SCD. As part of this, a set of 4 diagnostic criteria, with 2 modifiers to account for the influence of chronic pain, are proposed to define the types of acute pain observed in patients with SCD. PERSPECTIVE: This article presents a taxonomy for acute pain in patients with SCD. This taxonomy could help to standardize definitions of acute pain in clinical studies of patients with SCD.

Endurance training reduces exercise-induced acidosis and improves muscle function in a mouse model of sickle cell disease

Sickle cell disease (SCD) mice (Townes model of SCD) presented exacerbated exercise-induced acidosis and fatigability as compared to control animals. We hypothesize that endurance training could represent a valuable approach to reverse these muscle defects. Endurance-trained HbAA (HbAA-END, n=10), HbAS (HbAS-END, n=11) and HbSS (HbSS-END, n=8) mice were compared to their sedentary counterparts (10 HbAA-SED, 10 HbAS-SED and 9 HbSS-SED mice) during two rest - exercise - recovery protocols during which muscle energetics and function were measured. In vitro analyses of some proteins involved in muscle energetics, pH regulation and oxidative stress were also performed. Exercise-induced acidosis was lower in HbSS-END mice as compared to their sedentary counterparts during both moderate (p<0.001) and intense (p<0.1) protocols. The total force production measured during both protocols was higher in trained mice compared to sedentary animals. In vitro analyses revealed that enolase/citrate synthase ratio was reduced in HbSS-END (p<0.001) and HbAS-END (p<0.01) mice compared to their sedentary counterparts. In addition, malondialdehyde concentration was reduced in trained mice (p<0.05). In conclusion, endurance training would reverse the more pronounced exercise-induced acidosis, reduce oxidative stress and ameliorate some of the muscle function parameters in SCD mice.

Predictors and Correlates of Fatigue in Sickle Cell Disease Patients

Background: Although fatigue is the most important symptom of Sickle Cell Disease, the extent of it is unknown, and causal mechanisms are not well understood. This article explores biopsychosocial characteristics that can potentially contribute to fatigue in SCD. Materials and Methods: This cross-sectional, correlational study included 97 SCD patients who aged over 16 years and had records in Thalassemia Ward and Clinic of Shafa Hospital affiliated to Ahvaz University of Medical Sciences, Ahvaz, Iran. Data were collected from a self- reported demographic questionnaire, measuring depression, anxiety stress scale (DASS-21) and fatigue severity scale (FSS). Data analysis was done by descriptive statistics, independent sample t-tests, Pearson's correlation coefficient, one-way ANOVA and multiple stepwise regression. Results: More than 50% of study participants were mostly single women. A majority of patients had a diagnosis of HgbSS disease. Levels of depression, anxiety and stress were severe in more than half of the participants. About 65% of SCD patients reported signs of fatigue. Moreover, fatigue, depression, anxiety and stress had a high intercorrelation. Depression, blood transfusion, renal diseases and work status were predictors of fatigue according to the models used in this survey. Conclusion: The results of the study indicated that SCD patients who had depression, blood transfusions, SCD-related renal complications, students and working people experienced more fatigue. So, if fatigue is present, it is important to recognize the existence of these conditions or vice versa. Routine assessment and improved management of fatigue, effective interventions to reduce fatigue, are highly recommended for patients with SCD.

Psychometric Evaluation of the Patient-Reported Outcomes Measurement Information System Fatigue-Short Form Across Diverse Populations

BACKGROUND

The need for reliable, valid tools to measure patient-reported outcomes (PROs) is critical both for research and for evaluating treatment effects in practice. The Patient-Reported Outcomes Measurement Information System Fatigue-Short Form v1.0-Fatigue 7a (PROMIS F-SF) has had limited psychometric evaluation in various populations.

OBJECTIVES

The aim of the study is to examine psychometric properties of PROMIS F-SF item responses across various populations.

METHODS

Data from five studies with common data elements were used in this secondary analysis. Samples from patients with fibromyalgia, sickle cell disease, cardiometabolic risk, pregnancy, and healthy controls were used. Reliability was estimated using Cronbach's alpha. Dimensionality was evaluated with confirmatory factor analysis. Concurrent validity was evaluated by examining Pearson's correlations between scores from the PROMIS F-SF, the Multidimensional Fatigue Symptom Inventory-Short Form, and the Brief Fatigue Inventory. Discriminant validity was evaluated by examining Pearson's correlations between scores on the PROMIS F-SF and measures of stress and depressive symptoms. Known groups validity was assessed by comparing PROMIS F-SF scores in the clinical samples to healthy controls.

RESULTS

Reliability of PROMIS F-SF scores was adequate across samples, ranging from .72 in the pregnancy sample to .88 in healthy controls. Unidimensionality was supported in each sample. Concurrent validity was strong; across the groups, correlations with scores on the Multidimensional Fatigue Symptom Inventory-Short Form and Brief Fatigue Inventory ranged from .60 to .85. Correlations of the PROMIS F-SF with measures of stress and depressive mood were moderate to strong, ranging from .37 to .64. PROMIS F-SF scores were significantly higher in clinical samples compared to healthy controls.

DISCUSSION

Reliability and validity of the PROMIS F-SF were acceptable. The PROMIS F-SF is a suitable measure of fatigue across the four diverse clinical populations included in the analysis.

Moderate and intense muscular exercises induce marked intramyocellular metabolic acidosis in sickle cell disease mice

Sickle cell disease (SCD) is associated with an impaired oxygen delivery to skeletal muscle that could alter ATP production processes. The present study aimed to determine the effects of sickle hemoglobin (HbS) on muscle pH homeostasis in response to exercise in homozygous (HbSS, n = 9) and heterozygous (HbAS, n = 10) SCD (Townes) mice in comparison to control (HbAA, n = 10) littermates. Magnetic resonance spectroscopy of phosphorus 31 enabled to measure intramuscular pH and phosphocreatine (PCr) concentration during rest-stimulation-recovery protocols at two different intensities. Maximal activity of some enzymes involved in muscle energetics and content of proteins involved in pH regulation were also investigated. HbSS mice presented a more pronounced exercise-induced intramuscular acidosis, whatever the intensity of exercise. Moreover, the depletion of PCr was also exacerbated in HbSS mice in response to intense exercise as compared with both HbAA and HbAS mice ( P < 0.01). While no difference was observed concerning proteins involved in muscle pH regulation, the activity of enolase (a glycolytic enzyme) was higher in both HbSS and HbAS mice as compared with controls ( P < 0.05). Interestingly, HbAS mice presented also metabolic impairments as compared with their control counterparts. This study has identified for the first time an exacerbated exercise-induced intramuscular acidosis in SCD mice.

NEW & NOTEWORTHY The main finding of the present study was that the exercise-induced intramuscular acidosis was systematically more pronounced in sickle cell disease (SCD) mice as compared with their control counterparts. This result is important since it has been demonstrated in vitro that acidosis can trigger hemoglobin polymerization. From that point of view, our results tend to support the idea that high-intensity exercise may increase the risk of hemoglobin polymerization in SCD.

Impaired muscle force production and higher fatigability in a mouse model of sickle cell disease

Skeletal muscle function has been scarcely investigated in sickle cell disease (SCD) so that the corresponding impact of sickle hemoglobin is still a matter of debate. The purpose of this study was to investigate muscle force production and fatigability in SCD and to identify whether exercise intensity could have a modulatory effect. Ten homozygous sickle cell (HbSS), ten control (HbAA) and ten heterozygous (HbAS) mice were submitted to two stimulation protocols (moderate and intense) to assess force production and fatigability. We showed that specific maximal tetanic force was lower in HbSS mice as compared to other groups. At the onset of the stimulation period, peak force was reduced in HbSS and HbAS mice as compared to HbAA mice. Contrary to the moderate protocol, the intense stimulation protocol was associated with a larger decrease in peak force and rate of force development in HbSS mice as compared to HbAA and HbAS mice. These findings provide in vivo evidence of impaired muscle force production and resistance to fatigue in SCD. These changes are independent of muscle mass. Moreover, SCD is associated with muscle fatigability when exercise intensity is high.

Fatigue in Children With Sickle Cell Disease: Association With Neurocognitive and Social-Emotional Functioning and Quality of Life

Children with sickle cell disease (SCD) report fatigue in addition to acute and chronic pain, which can decrease overall health-related quality of life (HRQL). The primary objective of the current study was to investigate the relationship between fatigue and HRQL. Given limited prior research, secondary objectives included investigation of associations between fatigue and functional outcomes, including child neurocognitive and social-emotional functioning. Children aged 8 to 16 years (N=32) and a caregiver completed measures of fatigue, HRQL, pain, and neurocognitive and social-emotional functioning. Controlling for pain and number of SCD-related hospitalizations, hierarchical linear regression models were used to determine the impact of child-reported and parent-reported fatigue on child HRQL. Correlational analyses were used to explore the relationship between fatigue and additional child outcomes. Data indicated that children with SCD experience clinically relevant levels of fatigue, which independently predicts lower HRQL. Fatigue was also associated with lower working memory, executive functioning, and higher levels of internalizing symptoms. Given its observed impact on HRQL and relationship to functional outcomes, fatigue may be an important target of clinical, home, or school interventions. This practice may attenuate the burden of fatigue in these patients, and in turn, help improve the quality of life of children living with SCD.

Sleep disturbance, depression and pain in adults with sickle cell disease

BACKGROUND

Sleep disturbance and depression are commonly encountered in primary care. In sickle cell disease, depression is associated with pain, poor treatment compliance, and lower quality of life. The prevalence of sleep disturbance and its effect upon quality of life in adults with sickle cell disease is unknown. The goal of this study was to determine the prevalence of sleep disturbance and if it is associated with pain and depression in sickle cell disease.

METHODS

Three hundred twenty eight adults with sickle cell disease enrolled on the Bethesda Sickle Cell Cohort Study were assessed using the Pittsburgh Sleep Quality Index and Beck Depression Inventory II screening measures as a cross-sectional survey. Scores greater than 5 (Pittsburgh Sleep Quality Index) and 16 (Beck Depression Inventory II) defined sleep disturbance and depression, respectively. Clinical and laboratory parameters were also assessed.

RESULTS

The mean Pittsburgh Sleep Quality Index score was 8.4 (SD ± 4.2) indicating a 71.2% prevalence of sleep disturbance. The mean Beck Depression Inventory II score was 8.0 (SD ± 8.9). Sixty five (20.6%) participants had a score indicating depression, and half of these (10.0%) had thoughts of suicide. Both Pittsburgh Sleep Quality Index and Beck Depression Inventory II scores were significantly correlated (p < .001). The number of days with mild/moderate pain (p = .001) and a history of headaches (p = .005) were independently associated with depression by multivariate regression analysis. Patients with sleep disturbance were older (p = .002), had higher body mass index (p = .011), had more days of pain (p = .003) and more frequent severe acute painful events (emergency room visits and hospitalizations) during the previous 12 months (p < .001).

CONCLUSIONS

More than 70 percent of adults with sickle cell disease had sleep disturbance, while 21 percent showed evidence of clinical depression. Sleep disturbance and depression were correlated, and were most common among those with more frequent pain. Providers caring for adults with sickle cell disease and frequent pain should consider screening for these common co-morbidities. Additional study is needed to confirm these findings and to determine if treatments for pain, depression or sleep disturbances will improve quality of life measures in this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT00011648.

Overlapping biological mechanisms underlying sickle cell disease, stress, and depression: a stress-vulnerability framework

After participating in this activity, learners should be better able to:1. Evaluate the overlap between sickle cell disease (SCD) and depression.2. Identify sources of psychological stress and biological vulnerabilities toward developing depression in patients with SCD.3. Assess the potential mechanisms underlying SCD, stress, and depression.Depression is a common co-occurring disorder in persons with sickle-cell disease (SCD). Individuals with this chronic illness may be particularly vulnerable to depression. In addition to risk factors for depression specifically related to SCD, these individuals typically experience further psychological stress due to multiple risk factors in their environment. To date, however, little research has focused on the co-occurring biological mechanisms across these conditions and how those mechanisms may interact to produce depressive symptoms. In this review we use a stress-vulnerability framework to describe the sources of psychological stress and the SCD factors that increase the risk of depression. We suggest that several biological factors, such as nitric oxide and cytokines, may play an important role in co-occurring stress, SCD, and depression. The interaction of these factors may be of particular importance for understanding the comorbidity of SCD and depression. Implications for current treatment and future research are discussed.

Fatigue in adolescents and young adults with sickle cell disease: biological and behavioral correlates and health-related quality of life

This descriptive, correlational study examined fatigue and potential biological and behavioral correlates in adolescents and young adults with sickle cell disease. Sixty adolescents and young adults with sickle cell disease completed the Brief Fatigue Inventory, Multidimensional Fatigue Symptom Inventory-Short Form, Patient Reported Outcomes Measurement Information System (PROMIS) fatigue short form and measures of pain, sleep quality, anxiety, depressive mood, stress, disease severity, and quality of life. Blood samples were obtained for hemoglobin and cytokines. Fatigue scores were mostly moderate in severity. Fatigue interfered to a moderate degree with daily activities and correlated significantly with pain, sleep quality, state and trait anxiety, depressive mood, stress, and quality of life. Fatigue was correlated with hemoglobin on the PROMIS measure. Fatigue was not correlated with cytokines or age, nor differed by disease severity. Fatigue was common in these adolescents and young adults, interfered with daily activities such as school, work and exercise, and significantly correlated with several potentially modifiable factors. As life expectancy increases in sickle cell disease, research is needed to test interventions to reduce fatigue.

Insurance status as a sociodemographic risk factor for functional outcomes and health-related quality of life among youth with sickle cell disease

Youth with sickle cell disease (SCD) are at risk for functional limitations and poor health-related quality of life (QoL). This study examined sociodemographic factors that may interact with medical complications to reduce functional ability and QoL among youth with SCD. Fifty-three patient/caregiver pairs (children 8 to 18 years; M=12.3 y) with SCD completed the Functional Disability Inventory and Pediatric Quality of Life Inventory questionnaires. Medical database reviews were conducted to collect health care utilization, disease complications, and sociodemographic information; insurance type (public vs. private insurance) and family zip code to access Census tract data reflecting neighborhood distress. Insurance type, but not neighborhood sociodemographic risk indicators, was significantly associated with disease-related complications and QoL. There were significant differences in both health care utilization and QoL by insurance type. Complications were higher in the group with public insurance. Insurance type seems to be more strongly related to disease outcomes and QoL than neighborhood sociodemographic distress. Closer attention to the contribution of insurance type to health outcomes may provide important insight to potential barriers for disease management. These issues are critically important for health care efficiency and equity for poor and underserved children with chronic health conditions.

PedsQL™ Multidimensional Fatigue Scale in sickle cell disease: feasibility, reliability, and validity

BACKGROUND

Sickle cell disease (SCD) is an inherited blood disorder characterized by a chronic hemolytic anemia that can contribute to fatigue and global cognitive impairment in patients. The study objective was to report on the feasibility, reliability, and validity of the PedsQL™ Multidimensional Fatigue Scale in SCD for pediatric patient self-report ages 5-18 years and parent proxy-report for ages 2-18 years.

PROCEDURE

This was a cross-sectional multi-site study whereby 240 pediatric patients with SCD and 303 parents completed the 18-item PedsQL™ Multidimensional Fatigue Scale. Participants also completed the PedsQL™ 4.0 Generic Core Scales.

RESULTS

The PedsQL™ Multidimensional Fatigue Scale evidenced excellent feasibility, excellent reliability for the Total Scale Scores (patient self-report α = 0.90; parent proxy-report α = 0.95), and acceptable reliability for the three individual scales (patient self-report α = 0.77-0.84; parent proxy-report α = 0.90-0.97). Intercorrelations of the PedsQL™ Multidimensional Fatigue Scale with the PedsQL™ Generic Core Scales were predominantly in the large (≥0.50) range, supporting construct validity. PedsQL™ Multidimensional Fatigue Scale Scores were significantly worse with large effects sizes (≥0.80) for patients with SCD than for a comparison sample of healthy children, supporting known-groups discriminant validity. Confirmatory factor analysis demonstrated an acceptable to excellent model fit in SCD.

CONCLUSIONS

The PedsQL™ Multidimensional Fatigue Scale demonstrated acceptable to excellent measurement properties in SCD. The results demonstrate the relative severity of fatigue symptoms in pediatric patients with SCD, indicating the potential clinical utility of multidimensional assessment of fatigue in patients with SCD in clinical research and practice.