Chronic pain, a substantial public health issue, may be influenced by dietary patterns through systemic inflammation. This cross-sectional study explored the association between Dietary Inflammatory Index (DII) and chronic pain among 2581 American adults from NHANES data. The DII, ranging from - 4.98 to 4.69, reflects the inflammatory potential of the diet, with higher scores indicating greater pro-inflammatory capacity. Our findings showed no significant association between the continuous DII score and chronic pain prevalence. However, a nonlinear relationship emerged. When the DII was categorized, a significant association between higher DII scores (DII ≥ 2.5) and chronic pain prevalence was observed. The analysis uncovered a U-shaped pattern, with an inflection point at a DII score of - 0.9, indicating an association between both low and high levels of dietary inflammation are associated with higher pain prevalence. This nuanced interaction between dietary inflammation and chronic pain indicates the possibility of incorporating dietary modification into pain management strategies and underscores the need for further research into the long-term effects of diet on chronic pain.

Few studies have examined the associations between pain trajectories and cognitive function in older adults. This study explored the associations between pain trajectories and different cognitive domains in older adults from a network perspective.
Data on pain trajectories were derived from the Health and Retirement Study between 2010 and 2020 using latent class growth analyses. Measurements of key cognition domains, including memory, attention, calculation, orientation and language, were included. Linear regression and network analysis were performed to evaluate the associations between different pain trajectories and cognition.
A total of 9,551 older adults were included in this study and three trajectories of pain were identified. After controlling for the covariates, persistent severe pain trajectory was associated with poorer overall cognition, memory and calculation ability when compared to mild or non-persistent pain trajectory. In the pain and cognition network model, memory (expected influence (EI) = 0.62), language (EI = 0.58) and calculation (EI = 0.41) were the most central domains.
Pain trajectories appeared stable over time among older adults in this study. Severity of persistent pain was an important risk factor for poor cognition, especially in relation to memory and calculation domains. Interventions targeting memory, language and calculation domains might be useful in addressing cognitive decline in older adults with persistent pain.

UNASSIGNED: Both acute and persistent pain is associated with anxiety in clinical observations, but whether the underlying neural mechanisms differ is poorly understood.
UNASSIGNED: We used formalin or complete Freund\'s adjuvant (CFA) to induce acute or persistent pain. Behavioral performance was assessed by the paw withdrawal threshold (PWT), open field (OF), and elevated plus maze (EPM) tests. C-Fos staining was used to identify the activated brain regions. Chemogenetic inhibition was further performed to examine the necessity of brain regions in behaviors. RNA sequencing (RNA-seq) was used to identify the transcriptomic changes.
UNASSIGNED: Both acute and persistent pain could lead to anxiety-like behavior in mice. The c-Fos expression indicates that the bed nucleus of the stria terminalis (BNST) is activated only in acute pain, whereas the medial prefrontal cortex (mPFC) is activated only in persistent pain. Chemogenetic manipulation reveals that the activation of the BNST excitatory neurons is required for acute pain-induced anxiety-like behaviors. In contrast, the activation of the prelimbic mPFC excitatory neurons is essential for persistent pain-induced anxiety-like behaviors. RNA-seq reveals that acute and persistent pain induces differential gene expression changes and protein-protein interaction networks in the BNST and prelimbic mPFC. The genes relevant to neuronal functions might underline the differential activation of the BNST and prelimbic mPFC in different pain models, and be involved in acute and persistent pain-related anxiety-like behaviors.
UNASSIGNED: Distinct brain regions and gene expression patterns are involved in acute and persistent pain-related anxiety-like behaviors.

Pain is a common experience for inpatients, and intensive care unit (ICU) patients undergo more pain than other departmental patients, with an incidence of 50% at rest and up to 80% during common care procedures. At present, the management of persistent pain in ICU patients has attracted considerable attention, and there are many related clinical studies and guidelines. However, the management of transient pain caused by certain ICU procedures has not received sufficient attention. We reviewed the different management strategies for procedural pain in the ICU and reached a conclusion. Pain management is a process of continuous quality improvement that requires multidisciplinary team cooperation, pain-related training of all relevant personnel, effective relief of all kinds of pain, and improvement of patients\' quality of life. In clinical work, which involves complex and diverse patients, we should pay attention to the following points for procedural pain: (1) Consider not only the patient\'s persistent pain but also his or her procedural pain; (2) Conduct multimodal pain management; (3) Provide combined sedation on the basis of pain management; and (4) Perform individualized pain management. Until now, the pain management of procedural pain in the ICU has not attracted extensive attention. Therefore, we expect additional studies to solve the existing problems of procedural pain management in the ICU.

Psychological distress were found to be associated with chronic conditions and persistent pain. However, few studies explored the underlying pathways between them. This study aimed to analyze the path of chronic conditions and persistent pain on psychological distress through sleep quality and self-rated health. A total of 2,748 rural older people in Shandong, China were included in this study. Path analysis was performed by using Mplus 8.3 to examine the associations between chronic conditions, persistent pain, sleep quality, self-rated health, and psychological distress after adjusting for age, gender, education, and household income. The prevalence of psychological distress among the older adults in this study was 47.49%. Chronic conditions and persistent pain were indirectly associated with psychological distress through six mediating pathways: (1) the path from chronic conditions to psychological distress through sleep quality (β = 0.041, 95%CI: 0.015-0.067) and self-rated health (β = 0.064, 95%CI: 0.038-0.091), respectively, and a chain mediation existed (β = 0.007, 95% CI: 0.000-0.014); (2) the path of persistent pain and psychological distress through sleep quality (β = 0.058, 95% CI: 0.014-0.102) and self-rated health (β = 0.048, 95% CI: 0.000-0.096), respectively, also the chain mediation found (β = 0.009, 95% CI: 0.005-0.014). Psychological distress was associated with chronic conditions and persistent pain through decreased sleep quality and self-rated health among Chinese rural older people. Multi-pronged targeted intervention should be taken for older adults with chronic conditions and persistent pain.

Pain occurs at all stages of the patients who suffer from cancer. Owing to surgery and bone metastasis, breast cancer patients were usually disturbed by persistent pain. However, the pain-relief-right has not been respected enough in clinical cancer treatment. Whether pain has any adverse effects on cancer development is still unclear. In order to uncover this question, we established two preclinical animal models to explore the effects of pain on the tumor. For the first model, we mimicked neuropathic pain by sciatic nerve ligation on rats with xenograft tumor subcutaneously. For the second model, we mimicked the bone cancer pain by injecting tumor cell suspension into the tibial medullary cavity of rats with xenograft tumor subcutaneously. The rats with persistent pain showed higher tumor volume and tumor weight compared with the group without pain. Interestingly, when the neuropathic pain and bone cancer pain were relieved by drug administration, both the tumor volume and tumor weight were lowered compared with the group without pain relief. In summary, our study indicated that persistent pain acted as a contributing factor to tumor growth. Moreover, the pain relief could weakened the accelerating role of pain in tumor growth. Thus, we should be paid more attention to the cancer patients with persistent pain as well as cancer treatment.

Bortezomib is a first-line chemotherapeutic drug widely used for multiple myeloma and other nonsolid malignancies. Although bortezomib-induced persistent pain is easily diagnosed in clinic, the pathogenic mechanism remains unclear. Here, we studied this issue with use of a rat model of systemic intraperitoneal administration of bortezomib for consecutive 5days. Consisted with our previous study, we found that bortezomib treatment markedly induced mechanical allodynia in rats. Furthermore, we first found that bortezomib treatment significantly induced the upregulation of methylglyoxal in spinal dorsal horn of rats. Spinal local application of methylglyoxal also induced mechanical allodynia and central sensitization in normal rats. Moreover, administration of bortezomib upregulated the expression of receptors for advanced glycation end products (RAGE) and phosphorylated STAT3 (p-STAT3) in dorsal horn. Importantly, intrathecal injection of metformin, a known scavenger of methylglyoxal, significantly attenuated the upregulation of methylglyoxal and RAGE in dorsal horn, central sensitization and mechanical allodynia induced by bortezomib treatment, and blockage of RAGE also prevented the upregulation of p-STAT3, central sensitization and mechanical allodynia induced by bortezomib treatment. In addition, inhibition of STAT3 activity by S3I-201 attenuated bortezomib-induced mechanical allodynia and central sensitization. Local knockdown of STAT3 also ameliorated the mechanical allodynia induced by bortezomib administration. Our results suggest that accumulation of methylglyoxal may activate the RAGE/STAT3 signaling pathway in dorsal horn, and contributes to the spinal central sensitization and persistent pain induced by bortezomib treatment.

The purpose of this study is to evaluate the association between body mass index (BMI) and persistent pain after breast cancer surgery in a prospective study and synthesize available evidence through a meta-analysis. In the Women\'s Healthy Eating and Living (WHEL) Study, 3,088 women diagnosed of breast cancer were enrolled and assessed. After 4 years, a subgroup of 2,131 women was re-assessed for the pain information. Logistic regression models were used to assess the associations of baseline BMI and BMI change between baseline and 4 years of follow-up with general pain symptoms at 4 years of follow-up. We further synthesized all available evidence from observational studies by searching PubMed and Embase up to February 2017. In the WHEL study, baseline BMI was linearly associated with an increased risk of persistent pain at 4 years of follow-up (odds ratio (OR) (95% confidence interval (CI)): 1.07 (1.05-1.10)). After adjusting for baseline BMI, BMI change since baseline was associated with persistent pain (OR (95% CI) for every unit increase: 1.10 (1.04-1.16)). After searching the literature, additional eight studies were eligible to be included in the meta-analysis. After pooling estimates from all nine studies, there was a positive association with persistent pain development comparing obesity or overweight with normal weight. Available data suggested a linear relationship between BMI and persistent pain (OR (95% CI) for every one unit increment of BMI: 1.04 (1.02-1.07)). Overall, our analyses suggested that BMI might be positively associated with risk of persistent pain after breast cancer surgery.