Effect of Auriculotherapy on the Plasma Concentration of Biomarkers in Individuals with Knee Osteoarthritis

Effects of Auricular Stimulation on Inflammatory Parameters: Results of a Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The number of randomized controlled trials (RCTs) using auricular stimulation (AS) techniques, such as transauricular vagus nerve stimulation, auricular electrostimulation, auricular acupuncture, and acupressure in experimental and clinical settings has increased markedly over the last three decades. This systematic review evaluates the effects of AS on biomarkers of inflammation and stress responses.

MATERIALS AND METHODS

The following data bases were searched: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, and Scopus Data base. Data collection and analysis were conducted independently by two reviewers. Quality and risk assessments of the included studies were performed, and a meta-analysis of the effects of the most frequently assessed biomarkers was conducted using RevMan statistical software.

RESULTS

A total of 1122 patients and healthy volunteers from 27 RCTs were included in this systematic review; 81% of the participants were female, with a median age of 51 years. Pooled data of 18 studies showed a significant effect of AS regarding a reduction of serum C-reactive protein, tumor necrosis factor-α, interleukin (IL)-6, and IL-10. Although IL-4, IL1β, cortisol, substance P and calcitonin gene-related peptide, and adrenocorticotropic hormone did not show any changes, salivary amylase increased under AS.

CONCLUSIONS

The influence of inflammatory cytokines seems to be mediated by AS. More research is needed to investigate the effects of AS on the immunologic system in addition to its clinical significance in high-quality RCT.

Effects of auricular stimulation on weight- and obesity-related parameters: a systematic review and meta-analysis of randomized controlled clinical trials

Background

Over the last three decades, the number of randomized controlled trials (RCTs) using stimulation of auricular vagal sensory nerves by means of electrical stimulation, auricular acupuncture, or acupressure to support weight loss has increased markedly. This systematic review focuses on the effects of auricular stimulation (AS) on anthropometric parameters and obesity-related blood chemistry.

Methods and analysis

The following databases were searched until November 2021: MEDLINE (PubMed), EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, and Scopus Database. Data collection and analysis were conducted by two reviewers independently. Quality and risk assessment of included studies was performed using the risk of bias tool of the Cochrane Handbook, and the meta-analysis of the effect of the most frequently assessed biomarkers was conducted using the statistical software RevMan.

Results

The full texts of 1,274 studies were screened; 22 contained data on obesity-related outcomes, and 15 trials with 1,333 patients were included in the meta-analysis. The overall quality of the included trials was moderate. AS significantly reduced body mass index (BMI) (mean difference (MD) = -0.38 BMI points, 95% CI (-0.55 to -0.22), p < 0.0001), weight (MD = -0.66 kg, 95% CI (-1.12 to -0.20), p = 0.005), waist circumference (MD = -1.44 cm, 95% CI (-2.69 to -0.20), p = 0.02), leptin, insulin, and HOMA insulin resistance compared to controls. No significant reduction was found in body fat, hip circumference, ratio of waist/hip circumference, cholesterol, LDL, triglycerides, adiponectin, ghrelin, and glucose levels. The AS was safe throughout the trials, with only minor adverse reactions.

Conclusion

The study results suggest that a reduction of weight and BMI can be achieved by AS in obese patients; however, the size of the effect does not appear to be of clinical relevance. The effects might be underestimated due to active sham trials.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021231885.

Genetic liability for diet-derived circulating antioxidants, oxidative stress, and risk of osteoarthritis: a Mendelian randomization study

Background

Although well-documented, the causal relationships between diet-derived circulating antioxidants, oxidative stress, and osteoarthritis (OA) are equivocal. The objective of this study is to employ two-sample Mendelian randomization (MR) to investigate possible causal relationships among dietary-derived circulating antioxidants, oxidative stress damage indicators, and OA risk.

Methods

Single-nucleotide polymorphisms for diet-derived circulating antioxidants (ascorbate, β-carotene, lycopene, retinol, and α-and γ-tocopherol), assessed as absolute levels and metabolites, as well as oxidative stress injury biomarkers (GSH, GPX, CAT, SOD, albumin, and total bilirubin), were retrieved from the published data and were used as genetic instrumental variables. Summary statistics for gene-OA associations were obtained from publicly available and two relatively large-scale GWAS meta-analyses to date. The inverse-variance weighting method was utilized as the primary MR analysis. Moreover, multivariable MR was used to determine if mediators (BMI and smoking) causally mediated any connection. Furthermore, for each exposure, MR analyses were conducted per outcome database and then meta-analyzed.

Results

Genetically predicted absolute retinol level was causally associated with hip OA risk [odds ratios (ORs) = 0.40, 95% confidence interval (CI) = 0.24-0.68, FDR-corrected p = 0.042]. Moreover, genetically predicted albumin level was causally associated with total OA risk (OR = 0.80, 95% CI = 0.75-0.86, FDR-corrected p = 2.20E-11), as well as the risk of hip OA (OR = 0.75, 95% CI = 0.68-0.84, FDR-corrected p = 1.38E-06) and knee OA (OR = 0.82, 95% CI = 0.76-0.89, FDR-corrected p = 4.49E-06). In addition, MVMR confirmed that the effect of albumin on hip OA is independent of smoking initiation, alcoholic drinks per week, and moderate-to-vigorous physical activity levels but may be influenced by BMI.

Conclusion

Evidence from our study supports a potentially protective effect of high levels of retinol and albumin on OA risk.

Effects of the Whole-Body Vibration and Auriculotherapy on the Functionality of Knee Osteoarthritis Individuals

Knee osteoarthritis (KOA) is a degenerative disease of the knee joint. This study aims to evaluate the effects of whole-body vibration (WBV), auriculotherapy (AT), and the association of these techniques with the functionality of KOA individuals. Individuals (n = 120) were allocated an AT group (GAT), a WBV group (GWBV), an association group (GWBV + AT), and their respective controls (CGAT, CGWBMV, CGWBMV + AT). The WBV intervention was performed with 5–14 Hz in 3 min of working time with 1 min rest. The control group performed the protocol with the vibrating platform (VP) turned off. The AT intervention was performed with adhesive tapes, with seeds placed in the both ears on the Shenmen point, knee joint, and kidney. The control groups had seedless tape placed on both ears. The participants were instructed to press the adhesive tapes with the fingers three times per day (for 6 days) and to remove the adhesive tapes on the seventh day, before returning to the laboratory. The International Knee Documentation Committee (IKDC), the short physical performance battery (SPPB), and the anterior trunk flexibility (ATF) tests were applied. Acute and cumulative effects were determined. In first session (acute effect of the first session), significant improvements were observed in the groups GWBV (p = 0.03) and GWBV + AT (p = 0.04), and in the cumulative effect a significant improvement was observed in the groups GWBV (p = 0.02) and GWBV + AT (p = 0.01). Concerning the overall score of the SPPB, significant improvements were observed in the individuals of the GWBV (p = 0.01) and GWBV + AT (p = 0.03) groups (cumulative effect). No changes were found in the score for the IKDC. The WBV alone or associated with AT, besides being a safe and feasible strategy, likely produces physiological responses that improve the functionality of KOA individuals, considering the findings of the ATF and the score of the SPPB.

Identification and Analysis of Blood Gene Expression Signature for Osteoarthritis With Advanced Feature Selection Methods

Osteoarthritis (OA) is a complex disease that affects articular joints and may cause disability. The incidence of OA is extremely high. Most elderly people have the symptoms of osteoarthritis. The physiotherapy of OA is time consuming, and the chances of full recovery from OA are very minimal. The most effective way of fighting OA is early diagnosis and early intervention. Liquid biopsy has become a popular noninvasive test. To find the blood gene expression signature for OA, we reanalyzed the publicly available blood gene expression profiles of 106 patients with OA and 33 control samples using an automatic computational pipeline based on advanced feature selection methods. Finally, a compact 23-gene set was identified. On the basis of these 23 genes, we constructed a Support Vector Machine (SVM) classifier and evaluated it with leave-one-out cross-validation. Its sensitivity (Sn), specificity (Sp), accuracy (ACC), and Mathew's correlation coefficient (MCC) were 0.991, 0.909, 0.971, and 0.920, respectively. Obviously, the performance needed to be validated in an independent large dataset, but the in-depth biological analysis of the 23 biomarkers showed great promise and suggested that mRNA surveillance pathway and multicellular organism growth played important roles in OA. Our results shed light on OA diagnosis through liquid biopsy.