Evaluating elbow osteoarthritis within the prehistoric Tiwanaku state using generalized estimating equations (GEE).

OBJECTIVES:Studies of osteoarthritis (OA) in human skeletal remains can come with scalar problems. If OA measurement is noted as present or absent in one joint, like the elbow, results may not identify specific articular pathology data and the sample size may be insufficient to address research questions. If calculated on a per data point basis (i.e., each articular surface within a joint), results may prove too data heavy to comprehensively understand arthritic changes, or one individual with multiple positive scores may skew results and violate the data independence required for statistical tests. The objective of this article is to show that the statistical methodology Generalized Estimating Equations (GEE) can solve scalar issues in bioarchaeological studies. MATERIALS AND METHODS:Using GEE, a population-averaged statistical model, 1,195 adults from the core and one colony of the prehistoric Tiwanaku state (AD 500-1,100) were evaluated bilaterally for OA on the seven articular surfaces of the elbow joint. RESULTS:GEE linked the articular surfaces within each individual specimen, permitting the largest possible unbiased dataset, and showed significant differences between core and colony Tiwanaku peoples in the overall elbow joint, while also pinpointing specific articular surfaces with OA. Data groupings by sex and age at death also demonstrated significant variation. A pattern of elbow rotation noted for core Tiwanaku people may indicate a specific pattern of movement. DISCUSSION:GEE is effective and should be encouraged in bioarchaeological studies as a way to address scalar issues and to retain all pathology information

Behavioral Symptom Clusters, Inflammation, and Quality of Life in Chronic Low Back Pain

Purpose: Chronic low back pain is a prevalent condition, often involving an inflammatory process. Behavioral symptoms, including depressed mood, fatigue, and sleep disturbance, intensifies pain and reduces quality of life. The objectives of this pilot study were to identify behavioral symptom clusters (depressive mood, fatigue, poor sleep) in individuals with chronic low back pain, and to determine whether there are differences in pain, quality of life and inflammation (plasma IL-6) based on cluster membership. Design and Methods: In a cross-sectional pilot study, patients (N=69) completed measures of pain, depressive mood, fatigue, sleep, and quality of life. Blood was obtained for IL-6 measurement. Latent class analysis was used to identify clusters. Results: Findings revealed a two-class model, with Class 1 characterized by more depressive mood, fatigue, and sleep disturbance compared to Class 2. Class 1 participants reported worse quality of life than those in Class 2. Pain severity and pain interference were not significantly different between the classes. Levels of IL-6 were significantly greater in Class 1 participants compared to Class 2 with higher levels of IL-6 correlating with greater pain severity and sleep disturbances. Logistic regression revealed higher levels of IL-6 predicted Class 1 membership. Conclusion: Behavioral symptoms cluster exist in chronic low back pain patients and impact quality of life. Inflammation may contribute to the relationship between behavioral symptoms and pain severity. Clinical Implications: Recognition of behavioral symptom clusters can foster more comprehensive pain assessment and tailored interventions for patients with chronic low back pain

Social Support Is Inversely Associated With Sleep Disturbance, Inflammation, and Pain Severity in Chronic Low Back Pain

Background Chronic low back pain (CLBP) is a significant cause of disability, lost wages, and healthcare costs. Inflammatory mediators, such as interleukin-6 (IL-6), have been associated with LBP severity. Patients with CLBP commonly experience sleep disturbance, and poor sleep has been shown to increase pain severity and inflammation. In contrast, social support may benefit patients with CLBP by reducing pain intensity and inflammation. Objectives The purpose of this study was to examine the influence of social support on the relationships among sleep disturbance, inflammation, and pain severity in patients with CLBP. Methods In a cross-sectional study, men and women with CLBP were enrolled from an outpatient pain clinic. Participants completed psychometric instruments for social support, sleep quality, and pain severity. Blood samples were obtained for measurement of the pro-inflammatory cytokine IL-6 by enzyme-linked immunoassay. Results Linear regression revealed greater sleep disturbance predicted greater pain severity. In contrast, participants who reported higher social support had lower sleep disturbance and lower pain severity. Mediation analysis revealed sleep disturbance to mediate the relationship between social support and pain, such that sleep disturbance reduced the benefit of social support on pain severity. Furthermore, greater sleep disturbance and lower social support predicted increased IL-6. However, IL-6 did not mediate the relationship between social support and pain. Discussion The findings suggest that increased social support is associated with lower sleep disturbance, lower inflammation, and lower pain severity in patients with CLBP. Assessing the extent of social support and fostering social support as part of a comprehensive pain management program may benefit patients with CLBP. Interventions to strengthen social support systems and cultivate support from family and/or informal social networks may reduce symptom burden and improve quality of life

Nothing Lasts Forever: Environmental Discourses on the Collapse of Past Societies

The study of the collapse of past societies raises many questions for the theory and practice of archaeology. Interest in collapse extends as well into the natural sciences and environmental and sustainability policy. Despite a range of approaches to collapse, the predominant paradigm is environmental collapse, which I argue obscures recognition of the dynamic role of social processes that lie at the heart of human communities. These environmental discourses, together with confusion over terminology and the concepts of collapse, have created widespread aporia about collapse and resulted in the creation of mixed messages about complex historical and social processes