Vitamin D Intake and Magnetic Resonance Parameters for Knee Osteoarthritis: Data from the Osteoarthritis Initiative

Osteoporosis, Osteoarthritis, and Subchondral Insufficiency Fracture: Recent Insights

The increased incidence of osteoarthritis (OA), particularly knee and hip OA, and osteoporosis (OP), owing to population aging, have escalated the medical expense burden. Osteoarthritis is more prevalent in older women, and the involvement of subchondral bone fragility spotlights its association with OP. Notably, subchondral insufficiency fracture (SIF) may represent a more pronounced condition of OA pathophysiology. This review summarizes the relationship between OA and OP, incorporating recent insights into SIF. Progressive SIF leads to joint collapse and secondary OA and is associated with OP. Furthermore, the thinning and fragility of subchondral bone in early-stage OA suggest that SIF may be a subtype of OA (osteoporosis-related OA, OPOA) characterized by significant subchondral bone damage. The high bone mineral density observed in OA may be overestimated due to osteophytes and sclerosis and can potentially contribute to OPOA. The incidence of OPOA is expected to increase along with population aging. Therefore, prioritizing OP screening, early interventions for patients with early-stage OA, and fracture prevention measures such as rehabilitation, fracture liaison services, nutritional management, and medication guidance are essential.

Association between niacin intake and knee osteoarthritis pain and function: a longitudinal cohort study

BACKGROUND

This research investigates the relationship between niacin intake and knee osteoarthritis (OA) severity, focusing on pain and functional ability due to niacin's role as a NAD(P)+ precursor, promoting cellular energy, and offering anti-inflammatory, analgesic, and antioxidant effects.

METHODS

The population-based Osteoarthritis Initiative (OAI) cohort with radiographically confirmed knee OA was analyzed through a Food Frequency Questionnaire determining niacin intake and scores from the Knee Injury and Osteoarthritis Outcome Score (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), using generalized additive mixed models.

RESULTS

A significant correlation was pinpointed in 2375 OA patients (1001 men and 1374 women; 55.96% aged between 45 and 65 and 44.04% aged ≥65) between niacin intake and reduced knee pain and functional degrees after a 48-month follow-up, evident in improved KOOS and WOMAC scores (P < 0.05). The fully adjusted models estimated a decrease of 0.26 points for every additional 1 unit of Ln-niacin intake of daily niacin intake on the WOMAC pain subscale, 0.83 points on the WOMAC function subscale, and an increase of 1.71 and 1.58 on the KOOS pain and quality of life score. Strikingly, subgroups including middle-aged individuals, women, white race, obese individuals, and those with specific dietary habits showed a more substantial improvement with increased niacin.

CONCLUSION

The association between increased niacin intake and reduced pain and function scores, as well improved quality of life in knee OA patients, is significant. Certain cohorts, according to a stratified analysis, could see more considerable benefits with increased niacin consumption.

HIGHLIGHTS

• Increased niacin intake is linked to reduced knee pain and better function in OA patients. • Specific subgroups, such as middle-aged individuals, women, and those with certain dietary habits, benefit more from increased niacin consumption. • Niacin shows promise for enhancing the quality of life in knee OA patients by reducing pain and improving function.

Vitamin D and autophagy in knee osteoarthritis: A review

Knee osteoarthritis (KOA), the highly prevalent degenerative disease affecting the joint, perpetually devastates the health of the elderly. Of various mechanisms known to participate in KOA etiology, apoptosis of chondrocytes is widely regarded as the primary cause of cartilage degradation. It has been suggested that the induction of autophagy in chondrocytes could potentially prolong the progression of KOA by modulating intracellular metabolic processes, which may be helpful for ameliorating chondrocyte apoptosis and eventual cartilage degeneration. Autophagy, a physiological process characterized by intracellular self-degradation, has been reportedly implicated in various pathologic conditions including KOA. Interestingly, vitamin D has been shown to regulate autophagy in human chondrocytes through multiple pathways, specifically AMPK/mTOR signaling pathway. This observation underscores the potential of vitamin D as a novel approach for restoring the functionality and survivability of chondrocytes in KOA. Supporting vitamin D's clinical significance, previous studies have demonstrated its substantial involvement in the symptoms and irregular joint morphology observed in KOA patients, strengthening potential therapeutic efficacy of vitamin D in treatment of KOA. Herein, the purpose of this review was to determine the mechanisms underlying the multi-processes of vitamin D implicated in autophagy in several cells including chondrocytes, which would bring unique insights into KOA pathogenesis.

The Role of Vitamin D in the Development and Progression of Osteoarthritis

"Low levels of vitamin D in patients with osteoarthritis (ΟΑ) rather adversely affect the structure and function of articular cartilage. Low levels of vitamin D are also associated with joint pain, limited physical activity, quality of life, as well as decreased muscle strength, primarily in the lower extremities with adverse OA progression. A high percentage of low vitamin D levels was found in patients with OA and joint arthroplasty as well as a less satisfactory postoperative follow-up in patients with low vitamin D levels. The administration of vitamin D supplementation in patients with knee osteoarthritis has been associated with improved articular cartilage architecture, and reduced joint pain, combined with improved functionality and quality of life in patients with OA. "

Effectiveness of vitamin D supplementation on knee osteoarthritis - A target trial emulation study using data from the Osteoarthritis Initiative cohort

OBJECTIVE

To assess the real-world effectiveness of vitamin D supplementation in patients with knee osteoarthritis (KOA) by replicating a randomized controlled trial (RCT) design in an observational study.

METHOD

This study emulated a target trial using data from the Osteoarthritis Initiative (OAI). Eligible participants were ≥45 years, had symptomatic KOA and did not take vitamin D supplements in the past 30 days. A participant can enter the trial more than once. Participants were included in vitamin D group if they took ≥1,000 IU/day for ≥4 days/week in the past 30 days at the first follow-up visit after baseline. The control group did not use vitamin D in the past 30 days. Optimal propensity score matching at 1:1 ratio was performed. The primary outcome was change in knee pain 2 years after baseline measured by the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Secondary outcomes included WOMAC physical function and quantitative joint space width (JSW). Standardized mean difference (SMD) was used to compare the findings with previous RCTs.

RESULTS

A total of 236 person-trials in the vitamin D group were pair-matched with a control. Compared to the control group, vitamin D supplementation did not reach significant changes in WOMAC pain (SMD = -0.04, 95%CI [-0.21, 0.13]), physical function and radiographic JSW over 2 years. The SMDs were consistent with the effect sizes reported in previous RCTs.

CONCLUSION

Target trial emulation in the OAI cohort demonstrated findings close to published RCTs. This supports the future use of target trial emulation in evaluating other systemic therapies for KOA.

Identification for heavy metals exposure on osteoarthritis among aging people and Machine learning for prediction: A study based on NHANES 2011-2020

Objective

Heavy metals are present in many environmental pollutants, and have cumulative effects on the human body through water or food, which can lead to several diseases, including osteoarthritis (OA). In this research, we aimed to explore the association between heavy metals and OA.

Methods

We extracted 18 variables including age, gender, race, education level, marital status, smoking status, body mass index (BMI), physical activity, diabetes mellitus, hypertension, poverty level index (PLI), Lead (Pb), cadmium (Cd), mercury (Hg), selenium (Se), manganese (Mn), and OA status from National Health and Nutrition Examination Survey (NHANES) 2011-2020 datasets.

Results

In the baseline data, the t test and Chi-square test were conducted. For heavy metals, quartile description and limit of detection (LOD) were adopted. To analyze the association between heavy metals and OA among elderly subjects, multivariable logistic regression was conducted and subgroup logistic by gender was also carried out. Furthermore, to make predictions based on heavy metals for OA, we compared eight machine learning algorithms, and XGBoost (AUC of 0.8, accuracy value of 0.773, and kappa value of 0.358) was the best machine learning model for prediction. For interactive use, a shiny application was made (https://alanwu.shinyapps.io/NHANES-OA/).

Conclusion

The overall and gender subgroup logistic regressions all showed that Pb and Cd promoted the prevalence of OA while Mn could be a protective factor of OA prevalence among the elderly population of the United States. Furthermore, XGBoost model was trained for OA prediction.

Epidemiology of osteoarthritis

OBJECTIVE

To summarize the current state of the evidence regarding osteoarthritis (OA) prevalence, incidence and risk factors at the person-level and joint-level.

DESIGN

This was a narrative review that took a comprehensive approach regarding inclusion of potential risk factors. The review complements prior reviews of OA epidemiology, with a focus on new research and emerging topics since 2017, as well as seminal studies.

RESULTS

Studies continue to illustrate the high prevalence of OA worldwide, with a greater burden among older individuals, women, some racial and ethnic groups, and individuals with lower socioeconomic status. Modifiable risk factors for OA with the strongest evidence are obesity and joint injury. Topics of high interest or emerging evidence for a potential association with OA risk or progression include specific vitamins and diets, high blood pressure, genetic factors, metformin use, bone mineral density, abnormal joint shape and malalignment, and lower muscle strength/quality. Studies also continue to highlight the heterogenous nature of OA, with strong interest in understanding and defining OA phenotypes.

CONCLUSIONS

OA is an increasingly prevalent condition with worldwide impacts on many health outcomes. The strong evidence for obesity and joint injury as OA risk factors calls for heightened efforts to mitigate these risks at clinical and public health levels. There is also a need for continued research regarding how potential person- and joint-level risk factors may interact to influence the development and progression of OA.

Risk of Osteoarthritis is Positively Associated with Vitamin D Status, but Not Bone Mineral Density, in Older Adults in the United States

OBJECTIVE

We examined the risk of osteoarthritis (OA) according to vitamin D status and bone mineral density (BMD) using a cross-sectional nationally representative database.

METHODS

National Health and Nutrition Examination Survey (NHANES) data from 2007 to 2010 were used to assess the relationship between OA and vitamin D status in adults aged ≥40 years (n = 2934). NHANES data from 2005 to 2010 and 2013 to 2014 were analyzed to investigate the association between OA and BMD (n = 5949). Vitamin D status was categorized as serum 25-hydroxyvitamin D (25OHD) <20 ng/mL or ≥20 ng/mL. Bone health was classified according to T-score (normal, osteopenia, or osteoporosis) and BMD tertile. Risk of OA was assessed using logistic regression and adjusted for covariates.

RESULTS

Participants with serum 25OHD <20 ng/mL had a 37% lower risk of OA (95% confidence interval (CI) [0.39-0.99], P = 0.046). When stratified by sex, the odds ratio for OA in men with lower vitamin D status was 0.35 (95% CI [0.15-0.81], P = 0.02). No association was found in women. The risk for OA did not differ according to BMD tertile or T-score classification.

CONCLUSIONS

The risk of OA is lower in older men with 25OHD less than 20 ng/mL but not in older women. Bone mineral density is not associated with OA risk in older adults in the United States.