Investigating the Association of Metabolic Biomarkers With Knee Cartilage Composition and Structural Abnormalities Using MRI: A Pilot Study

Regulating lipid metabolism in osteoarthritis: a complex area with important future therapeutic potential

BACKGROUND

Osteoarthritis (OA), which is characterized by pain, inflammation and pathological changes, is associated with abnormal lipid metabolism. Extensive studies have been conducted on the potential functions of lipids including cholesterol, fatty acids (FAs) and adipokines.

MATERIALS AND METHODS

By searching and screening the literature included in the PubMed and Web of Science databases from 1 January 2019 to 1 January 2024, providing an overview of research conducted on lipid metabolism and OA in the last 5 years.

RESULTS

In addition to adiponectin, several studies on the effects of lipid metabolism on OA have been consistent and complementary. Total cholesterol, triglycerides, low-density lipoprotein cholesterol, adipsin, leptin, resistin, saturated FAs, monounsaturated FAs, FA-binding protein 4 and the ratios of the FAs hexadecenoylcarnitine (C16:1) to dodecanoylcarnitine and C16:1 to tetradecanoylcarnitine induced mostly deleterious effects, whereas high-density lipoprotein cholesterol and apolipoprotein A/B/D had a positive impact on the health of joints. The situation for polyunsaturated FAs may be more complicated, as omega-3 increases the genetic susceptibility to OA, whereas omega-6 does the opposite.

Alterations in lipid or adipokine levels and the resulting pathological changes in cartilage and other tissues (such as bone and synovium) ultimately affect joint pain, inflammation and cartilage degradation. Lipid or adipokine regulation has potential as a future direction for the treatment of OA, this potential avenue of OA treatment requires high-quality randomized controlled trials of combined lipid regulation therapy, and more in-depth in vivo and in vitro studies to confirm the underlying mechanism.

Evaluation of Meniscus Elasticity with Shear Wave Elastography in Patients with Type 2 Diabetes Mellitus

RATIONALE AND OBJECTIVES

We aimed to evaluate possible elasticity changes in the menisci of patients with type 2 diabetes mellitus using shear wave elastography (SWE).

MATERIALS AND METHODS

The medial and lateral menisci of the right and left knee of 40 patients (20 males, 20 females) with type 2 diabetes mellitus and 40 healthy controls (20 males, 20 females) were evaluated between June 2024 and September 2024. All patients and the control group were evaluated with MRI for meniscal pathology. Medial and lateral meniscal thicknesses were measured in the coronal plane in grayscale US mode. In both groups, the SWE measurement range was set to 0-8.2m/s and 0-200kPa and 2 mm ROIs were placed on the medial and lateral meniscal bodies of both knees in the coronal plane. The stiffness values of the meniscus were measured three times and the mean value of these three measurements was recorded.

RESULTS

There was no significant difference between meniscal thickness in diabetic patients and control group (p > 0.05). Bilateral meniscal stiffness values of diabetic patients were higher than the control group and there was a statistically significant difference (p < 0.05). There were moderate to strong positive correlations between meniscal stiffness values and fasting blood glucose and HA1c values in the diabetic patients(p < 0.05).

CONCLUSION

This is the first study to demonstrate that meniscus stiffness increases in diabetic patients. SWE is a quantitative imaging method that can be used to detect meniscal pathologies that may develop due to diabetes.

The effect of pentosan polysulfate sodium for improving dyslipidaemia and knee pain in people with knee osteoarthritis: A pilot study

Objective

To evaluate the efficacy and safety of pentosan polysulfate sodium (PPS, Elmiron®) for dyslipidaemia and knee osteoarthritis (OA) related symptoms.

Method

This was a single-arm, open-label, prospective, non-randomised pilot study. People with painful knee OA and a history of primary hypercholesterolemia were included. PPS was taken orally in a dosage of 10 ​mg/kg once every 4 days for 5 weeks for two cycles. There was 5 weeks of no medication between the cycles. The main outcomes included the change in lipidemia levels, the change in knee OA-related symptoms assessed by pain numerical rating scale (NRS) and Knee Osteoarthritis Outcome Score (KOOS), and knee MRI semi-quantitative score. The changes were analysed using paired t-tests.

Results

38 participants were included, with a mean age of 62.2 years. We found a statistically significant decrease in total cholesterol (from 6.23 ​± ​0.74 to 5.95 ​± ​0.77 ​mmol/L; P ​= ​0.01) and low-density lipoprotein (from 4.03 ​± ​0.61 to 3.82 ​± ​0.61 ​mmol/L; P ​= ​0.009) from baseline to week 16. Knee pain NRS was significantly reduced at weeks 6, 16 and 26 from 6.39 ​± ​1.33 to 4.18 ​± ​1.99, 3.63 ​± ​2.28 and 4.38 ​± ​2.55, respectively (P ​< ​0.001). However, there was no significant difference in terms of the primary outcome of triglyceride levels before and after treatment. The most common AEs were positive faecal occult blood tests, followed by headache and diarrhoea.

Conclusion

The findings suggest that PPS has promising effects on improving dyslipidaemia and symptomatic pain relief in people with knee OA.

Biomarkers of Osteoarthritis—A Narrative Review on Causal Links with Metabolic Syndrome

Development of OA (OA) is multifactorial and is strongly associated with risk factors such as aging, trauma, metabolic disorders, and obesity. Metabolic Syndrome (MetS)-associated OA, collectively coined MetS-OA, is an increasingly recognized entity in which metabolic disorders and low-grade inflammation play a key mechanistic role in the disruption of joint homeostasis and cartilage degradation. Although there have been enormous efforts to discover biomarkers of MetS and OA, studies investigating a pathophysiological link between MetS and OA are relatively limited, and no serum blood marker has proved diagnostic so far. OA biomarkers that are necessary to discriminate and diagnose early disease remain to be elicited, explained in part by limited prospective studies, and therefore limited tools available to utilize in any prognostic capacity. Biomarker validation projects have been established by the Biomarker Consortium to determine biochemical markers demonstrating predictive validity for knee OA. Given that the metabolic constituents of MetS are treatable to varying extents, it stands to reason that treating these, and monitoring such treatment, may help to mitigate deleterious links with OA development. This narrative review will describe the current state of biomarker identification and utility in OA associated with MetS. We discuss the pathophysiological mechanisms of disease according to constituent pathologies of MetS and how identification of biomarkers may guide future investigation of novel targets.

Tissue Engineering of Canine Cartilage from Surgically Debrided Osteochondritis Dissecans Fragments

This study in dogs explored the feasibility of using cartilage fragments removed and discarded during routine palliative surgery for osteochondritis dissecans (OCD) as a source of primary chondrocytes for scaffold-free cartilage tissue-engineering. Primary chondrocytes were obtained from three OCD donors and one age-matched healthy articular cartilage (HAC) donor. After monolayer expansion of primary cells, a three-dimensional spherical suspension culture was implemented. Following this stage, cells were seeded at a high density into custom-made agarose molds that allowed for size and shape-specific constructs to be generated via a method of cellular self-assembling in a scaffold-free environment. Fifty-eight neocartilage constructs were tissue-engineered using this methodology. Neocartilage constructs and native cartilage from shoulder joint were subjected to histological, mechanical, and biochemical testing. OCD and HAC chondrocytes-sourced constructs had uniformly flat morphology and histology consistent with cartilage tissue. Constructs sourced from OCD chondrocytes were 1.5-times (32%) stiffer in compression and 1.3 times (23%) stronger in tension than constructs sourced from HAC chondrocytes and only 8.7-times (81%) less stiff in tension than native tissue. Constructs from both cell sources consistently had lower collagen content than native tissue (22.9%/dry weight [DW] for OCD and 4.1%/DW for HAC vs. 51.1%/DW native tissue). To improve the collagen content and mechanical properties of neocartilage, biological and mechanical stimuli, and thyroid hormone (tri-iodothyronine) were applied to the chondrocytes during the self-assembling stage in two separate studies. A 2.6-fold (62%) increase in compressive stiffness was detected with supplementation of biological stimuli alone and 5-fold (81%) increase with combined biological and mechanical stimuli at 20% strain. Application of thyroid hormone improved collagen content (1.7-times, 33%), tensile strength (1.8-times, 43%), and stiffness (1.3-times, 21%) of constructs, relative to untreated controls. Collectively, these data suggest that OCD chondrocytes can serve as a reliable cell source for cartilage tissue-engineering and that canine chondrocytes respond favorably to biological and mechanical stimuli that have been shown effective in chondrocytes from other animal species, including humans.