Chronic Musculoskeletal Pain and Chronic Widespread Pain in Chile: Prevalence Study Performed as Part of the National Health Survey

Topical Chinese patent medicines for chronic musculoskeletal pain: systematic review and trial sequential analysis

PURPOSE

Chronic musculoskeletal pain (CMP) is defined as persistent or recurrent pain that occurs in the joints, musculo-soft tissue, spine or bones for more than three months and is not completely curable. Although topical Chinese patent medicine (CPM) is the most extensively utilized medication in Asia and is widely used for pain management, its efficacy remains controversial. This article presents a systematic review of clinical studies on the therapeutic properties of topical CPM for CMP patients to better inform clinical decision-making and provide additional and safer treatment options for patients with CMP.

METHOD

We performed a comprehensive search on PubMed, Cochrane Library, web of science and Chinese databases (CNKI and WanFang data) from 2010 to 2022. In all the studies, knee osteoarthritis, cervical spondylosis, low back pain, and periarthritis of shoulder met the International Pain Association definition of chronic musculoskeletal pain. We included only randomized controlled trials (RCTs) using topical CPM primarily for chronic musculoskeletal pain in adults. To determine the effect of topical CPM on clinical symptoms, we extracted the Visual Analog Scale (VAS, range 0-10) and the Western Ontario and McMaster Universities Arthritis Index pain scores (WOMAC pain, range 0-20), in which the lower the score, the better the results. We also accepted the comprehensive outcome criteria developed by the Chinese National Institute of Rheumatology as an endpoint (total effectiveness rate, range 0-100%, higher score = better outcome), which assesses the overall pain, physical function and wellness. Finally, trial sequential analysis of VAS pain score and total effectiveness rate was performed using TSA software.

RESULTS

Twenty-six randomized controlled trials (n = 3180 participants) compared topical CPM with oral Nonsteroidal Anti-inflammatory Drugs (NSAIDs) (n = 15), topical NSAIDs (n = 9), physiotherapy (n = 5), exercise therapy (n = 4), and intra-articular Sodium hyaluronate injection (n = 2). Sixteen studies found that topical CPM was statistically significant in improving CMP pain (measured by VAS pain and Womac pain scores)(p < 0.05), and 12 studies found topical CPMs to be more clinically effective (assessed by ≥ 30% reduction in symptom severity) in treating patients with CMP (p < 0.05). Trial sequential analysis indicates that the current available evidence is robust, and further studies cannot reverse this result. In most of the studies, randomisation, allocation concealment and blinding were not sufficiently described, and no placebo-controlled trials were identified.

CONCLUSION

Most studies showed superior analgesic effects of topical CPM over various control treatments, suggesting that topical CPM may be effective for CMP and is an additional, safe and reasonable treatment option. These reported benefits should be validated in higher-quality RCTs.

Loss of Health State Utilities Attributable to Obesity

OBJECTIVES

This study aimed to quantify the association between the loss of health state utilities (LHSU) and obesity, considering different obesity categories. This is relevant to interventions economic evaluations and for public policy decision planning.

METHODS

Using data from the Chilean National Health Survey, this study uses linear regression models and counterfactual scenarios to calculate the prevalent burden, population averages, and total sum of LHSU attributable to obesity for the Chilean national level on people older than 15 years, year 2017. Adjustments for socioeconomic status and associated noncommunicable diseases (NCDs) are considered. Calculating the LHSU using these methods enables the approximation of loss of prevalent quality-adjusted life-years (QALYs).

RESULTS

The raw obesity LHSU burden was 9.1% (95% uncertainty interval [UI] 5.1-13). When adjustment is considered, the LHSU attributable to obesity reaches 4.6% (95% UI 0.6-8.5) being responsible for 121 045 prevalent QALYs. Socioeconomic status adjusted analysis of higher body mass index (BMI, in kg/m²) categories of obesity shows a dose-response effect for LHSU, being the BMI ≥ 40 category with the highest population average of attributable LHSU (10.1; 95% UI 5.5-14.5, scale 0 [full health] to 100 [dead]). Burden for BMI ≥ 35 categories showed the biggest change after NCD adjustment.

CONCLUSIONS

Obesity carries a significant burden of QALY loss. Policy decision-making addressing obesity should focus specially on the BMI ≥ 40 group. NCD comorbidity should be considered for policies addressing the BMI ≥ 35 group.

Chronic pain in Chile: first prevalence report of noncancer chronic pain, fibromyalgia, and neuropathic pain and its associated factors

ABSTRACT

Although we know chronic pain (CP) affects approximately 30% of people in developed countries, data from Latin America are scarce. Moreover, prevalence of specific CP conditions, such as chronic noncancer pain (CNCP), fibromyalgia (FM), and neuropathic pain (NP), is unknown. To estimate them in Chile, we prospectively enrolled 1945 participants (61.4% women and 38.6% men), aged 38 to 74 years, from an agricultural town who answered a Pain Questionnaire, the Fibromyalgia Survey Questionnaire, and Douleur Neuropathique 4 (DN4) to identify CNCP, FM, and NP, respectively. The estimated prevalence of CNCP was 34.7% (95% CI 32.6; 36.8), with an average duration of 32.3 months (SD ± 56.3), producing deep impairments in daily activities, sleep, and mood. We estimated a prevalence of 3.3% for FM (95% CI 2.5; 4.1) and 12% for NP (95% CI 10.6; 13.4). Female sex, fewer school years, and depressive symptoms were associated with FM and NP, whereas diabetes was only associated with NP. We standardized the results from our sample against the whole Chilean population and found no significant difference to our crude estimates. This is in line with studies from developed countries, highlighting the idea that despite genetic and environmental differences, the conditions that confer risk to CNCP remain stable.

Glutamatergic systems in neuropathic pain and emerging non-opioid therapies

Neuropathic pain, a disease of the somatosensory nervous system, afflicts many individuals and adequate management with current pharmacotherapies remains elusive. The glutamatergic system of neurons, receptors and transporters are intimately involved in pain but, to date, there have been few drugs developed that therapeutically modulate this system. Glutamate transporters, or excitatory amino acid transporters (EAATs), remove excess glutamate around pain transmitting neurons to decrease nociception suggesting that the modulation of glutamate transporters may represent a novel approach to the treatment of pain. This review highlights and summarizes (1) the physiology of the glutamatergic system in neuropathic pain, (2) the preclinical evidence for dysregulation of glutamate transport in animal pain models, and (3) emerging novel therapies that modulate glutamate transporters. Successful drug discovery requires continuous focus on basic and translational methods to fully elucidate the etiologies of this disease to enable the development of targeted therapies. Increasing the efficacy of astrocytic EAATs may serve as a new way to successfully treat those suffering from this devastating disease.