Micronutrients: Essential Treatment for Inflammatory Arthritis?

An atlas of causal association between micronutrients and osteoarthritis

OBJECTIVE

This study examines the causal relationships between serum micronutrients and site-specific osteoarthritis (OA) using Mendelian Randomization (MR).

METHODS

This study performed a two-sample MR analysis to explore causal links between 21 micronutrients and 11 OA outcomes. These outcomes encompass overall OA, seven site-specific manifestations, and three joint replacement subtypes. Sensitivity analyses using MR methods, such as the weighted median, MR-Egger, and MR-PRESSO, assessed potential horizontal pleiotropy and heterogeneity. Genome-wide association summary statistical data were utilized for both exposure and outcome data, including up to 826,690 participants with 177,517 OA cases. All data was sourced from Genome-wide association studies datasets from 2009 to 2023.

RESULTS

In the analysis of associations between 21 micronutrients and 11 OA outcomes, 15 showed Bonferroni-corrected significance (P < 0.000216), without significant heterogeneity or horizontal pleiotropy. Key findings include strong links between gamma-tocopherol and spine OA (OR = 1.70), and folate with hand OA in finger joints (OR = 1.15). For joint replacements, calcium showed a notable association with a reduced likelihood of total knee replacement (TKR) (OR = 0.52) and total joint replacement (TJR) (OR = 0.56). Serum iron was significantly associated with an increased risk of total hip replacement (THR) (OR = 1.23), while folate indicated a protective effect (OR = 0.95). Various sex-specific associations were also uncovered.

CONCLUSION

These findings underscore the critical role of micronutrients in osteoarthritis, providing valuable insights for preventive care and potential enhancement of treatment outcomes.

Diagnostic and therapeutic value of intracellular biomarker testing in chronic pain

Aim: Micronutrient and metabolic compound supplementation as a method of treating chronic pain is not well understood. Case: A 58 year-old woman presented with refractory painful neuropathy. She did not respond to conservative treatment and was seeking spinal cord stimulator implantation. She underwent a biomarker panel that revealed low intracellular levels of multiple compounds. As she supplemented her deficiencies, her symptoms fully resolved, and the implant was no longer indicated. Discussion: Micronutrient and metabolic compound testing could potentially expand non-invasive treatment options for patients with refractory chronic pain. Caution should be exercised given limited regulatory oversight in the supplement industry and actively ongoing nutritional research. Conclusion: Biomarker testing panels may be a useful adjunct in the management of refractory neuropathic pain.

The impact of dietary interventions in psoriatic arthritis

PURPOSE OF REVIEW

Psoriatic arthritis (PsA) is a common form of inflammatory arthritis that affects people with psoriasis. Both psoriasis and PsA are associated with metabolic diseases including obesity, hypertension, hyperlipidaemia, diabetes mellitus, fatty liver disease, and cardiovascular disease including myocardial infarction. Dietary interventions for psoriatic disease have been of great interest, particularly among patients with PsA.

RECENT FINDINGS

Herein, we review the evidence for dietary intervention in psoriatic arthritis. To date, weight loss among patients who are obese has the greatest evidence for benefit. We also examine the evidence for fasting, nutrient supplementation, and specific diets as adjunct therapeutic strategies.

SUMMARY

While the data do not clearly support a single dietary intervention across the disease, weight loss among those who are obese results in improved PsA disease activity and physical function. Additional studies are needed to better understand the impact of diet on psoriatic arthritis.

Testing relationship between tea intake and the risk of rheumatoid arthritis and systemic lupus erythematosus: a Mendelian randomization study

BACKGROUND

We performed Mendelian randomization (MR) to assess the causal effect of tea intake on rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

Genetic instruments for tea intake were obtained from a large genome-wide association study (GWAS) dataset of the UK Biobank. Genetic association estimates for RA (6236 cases and 147,221 controls) and SLE (538 cases and 213,145 controls) were obtained from the FinnGen study through the IEU GWAS database.

RESULTS

MR analyses using the inverse-variance weighted method showed that tea intake was not associated with risk of RA [odds ratio (OR) per standard deviation increment in genetically predicted tea intake = 0.997, 95% confidence interval (CI) 0.658-1.511] and SLE (OR per standard deviation increment in genetically predicted tea intake = 0.961, 95% CI 0.299-3.092). Weighted median, weighted mode, MR-Egger, leave-one-out and multivariable MR controlling for several confounding factors including current tobacco smoking, coffee intake, and alcoholic drinks per week yielded completely consistent results. No evidence of heterogeneity and pleiotropy was found.

CONCLUSION

Our MR study did not suggest a causal effect of genetically predicted tea intake on RA and SLE.

Circulating Level of Blood Iron and Copper Associated with Inflammation and Disease Activity of Rheumatoid Arthritis

This study aims to compare the concentrations of circulating levels of iron, zinc, and copper in blood samples of rheumatoid arthritis (RA) patients which determine the correlations with inflammation and disease activity. A total of 102 RA patients and 66 healthy controls were enrolled. Circulation of iron, zinc, and copper levels in whole blood were assessed. Hemoglobin, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), anticyclic citrullinated peptide antibody (anti-CCP) levels were collected. A meta-analysis was performed to validate our findings. Single and multiple variate generalized linear regression were applied to identify the correlation between trace elements and clinical characteristics. Blood copper level was significantly higher in RA patients (P < 0.001), while iron and zinc levels were decreased (P < 0.001 and P = 0.02, respectively). Meta-analysis confirmed our findings for zinc (SMD =  - 1.17, P < 0.001) and copper (SMD = 1.24, P < 0.001). Copper level was positively correlated with DAS28-CRP (r = 0.35, P < 0.01), CRP (r = 0.45, P < 0.01) and ESR (r = 0.58, P < 0.01). Iron level was negatively correlated with DAS28-CRP (r =  - 0.37, P < 0.01), CRP (r =  - 0.46, P < 0.01) and ESR (r =  - 0.55, P < 0.01). Circulating blood copper was significantly higher and positively correlated with DAS28-CRP and inflammatory markers, while circulating blood iron was decreased and negatively correlated with DAS28-CRP and inflammatory markers in RA patients.