Skin pentosidine in very early hip/knee osteoarthritis (CHECK) is not a strong independent predictor of radiographic progression over 5 years follow-up

Skin autofluorescence, a non-invasive biomarker of advanced glycation end products, and its relation to radiographic and MRI based osteoarthritis

OBJECTIVES

Accumulation of advanced glycation end products (AGEs) in articular cartilage during aging has been proposed as a mechanism involved in the development of osteoarthritis (OA). Therefore, we investigated a cross-sectional relationship between skin AGEs, a biomarker for systemic AGEs accumulation, and OA.

METHODS

Skin AGEs were estimated with the AGE Reader™ as skin autofluorescence (SAF). Knee and hip X-rays were scored according to Kellgren and Lawrence (KL) system. KL-sum score of all four joints was calculated per participant to assess severity of overall radiographic OA (ROA) including or excluding those with prosthesis. Knee MRI of tibiofemoral joint (TF_MRI) was assessed for cartilage loss. Sex-stratified regression models were performed after testing interaction with SAF.

RESULTS

2,153 participants were included for this cross-sectional analysis. In women (n = 1,206) for one unit increase in SAF, the KL-sum score increased by 1.15 (95% confidence interval = 1.00-1.33) but excluding women with prosthesis, there was no KL-sum score increase [0.96 (0.83-1.11)]. SAF was associated with higher prevalence of prosthesis [Odds ratio, OR = 1.67 (1.10-2.54)] but not with ROA [OR = 0.83 (0.61-1.14)] when compared to women with no ROA. In men (n = 947), there was inconclusive association between SAF and KL sum score or prosthesis. For TF_MRI (n = 103 women), SAF was associated with higher prevalence of cartilage loss, full-thickness [OR = 5.44 (1.27-23.38)] and partial-thickness [OR = 1.45 (0.38-5.54)], when compared to participants with no cartilage loss.

CONCLUSION

Higher SAF in women was associated with higher prosthesis prevalence and a trend towards higher cartilage loss on MRI. Our data presents inconclusive results between SAF and ROA in both sexes.

Association of dietary intake, medication and anthropometric indices with serum levels of advanced glycation end products, caspase-3, and matrix metalloproteinase-9 in diabetic patients

Background and objective

Increased serum levels of advanced glycation end products (AGEs), caspase-3 (Cas-3) and matrix metalloproteinase-9 (MMP-9) have been reported in diabetic patients. This study aimed to evaluate association of anthropometric, dietary, and therapeutic factors with serum levels of methylglyoxal (MGO), carboxymethyl lysine (CML), pentosidine (Pen), Cas-3, and MMP-9 in diabetic patients.

Methods

The current study included 36 diabetic subjects. Dietary intake of the participants was assessed using three-day 24-h recall survey and anthropometric indices were measured. Demographic factors and medication intake of every subject were obtained. Serum levels of CML, MGO, Pen, MMP-9, and Cas-3 were measured using ELISA method.

Results

Gliclazide consumption was positively correlated with MMP-9 and Cas-3, but not AGEs levels. Females had higher MGO level compared with males. Further, CML levels were negatively correlated with BMI and WHR. Dietary protein intake was positively correlated with MMP-9, Cas-3, and MGO levels. As well as dietary energy and fat intake had significant positive relationship with serum Cas-3 concentration.

Conclusion

It is concluded that anthropometric characteristics, dietary intake, and therapeutic medications are possible factors that may determine the circulating levels of AGEs, MMP-9, and Cas-3 in patients with diabetes.

Evaluation of Early Knee Osteoarthritis Using Biomechanical and Biochemical Markers

Altered cellular mechano-transduction and biochemistry lead to degeneration of articular cartilage in people with knee osteoarthritis. However, the influence of low-moderate exposure to weight-bearing activity such as squatting on cartilage metabolism has not been adequately studied. The current study explored associations between knee adduction moment (KAM) during walking, biochemical markers and daily squat exposure. 3D gait analysis was used to determine external loads acting on the knee as indicators of joint compressive forces whereas biomarkers-Urine type-II-collagen-telopeptide (uCTxII), antioxidant and phospholipase A2 (PLA2) activity reflected on articular cartilage status. Following ethical approval, 66 participants with varying daily squat exposure (non-squatters [n = 21, exposure = 0 min]; activity of daily living [ADL] squatters [n = 16, exposure = 34 min]; occupational squatters [n = 13, exposure = 102 min]) and people with grade 2-3 knee osteoarthritis (n = 16, exposure = 28 min) were evaluated using 3D gait and biomarker analysis. The PLA2 activity was lowest in ADL squatters while occupational squatters demonstrated highest activity (p < 0.05). KAM and urine biomarker were similar among the groups. Moderate-strong positive association was observed between sweat PLA2 activity and age (r = 0.819, p = 0.004), daily squat exposure and biomarker uCTxII (r = 0.604, p = 0.013), antioxidant activity and Right-KAM (r = -0.917, p = 0.001), and Left-KAM (r = -0.767, p = 0.016), in people with knee OA. Healthy people demonstrated weak positive associations between KAM, uCTxII, and BMI. Associations between non-invasive biomechanical and biochemical markers indicate their potential use to identify early knee osteoarthritis. Studies with larger sample size are necessary to support prescription of body weight joint loading activities such as squatting in moderation, to delay functional decline caused by knee OA.

Type 2 diabetes mellitus and osteoarthritis

OBJECTIVES

Type 2 diabetes mellitus (T2DM) and osteoarthritis (OA) are common diseases that frequently co-exist, along with overweight/obesity. While the mechanical impact of excess body weight on joints may explain lower limb OA, we sought to explore whether T2DM is linked to OA outside of excess weight and whether T2DM may play a role in OA pathophysiology. The consequence of T2DM on OA outcomes is a question of research interest.

METHODS

We conducted a critical review of the literature to explore the association between T2DM and OA, whether any association is site-specific for OA, and whether the presence of T2DM impacts on OA outcomes. We also reviewed the literature to assess the safety of anti-OA treatments in patients with T2DM.

RESULTS

T2DM has a pathogenic effect on OA through 2 major pathways involving oxidative stress and low-grade chronic inflammation resulting from chronic hyperglycemia and insulin resistance. T2DM is a risk factor for OA progression and has a negative impact on arthroplasty outcomes. Evidence is mounting for safety concerns with some of the most frequently prescribed anti-OA medications, including paracetamol, non-steroidal anti-inflammatory drugs, and corticosteroid injections, while other anti-OA medications may be safely prescribed in OA patients with T2DM, such as glucosamine and intra-articular hyaluronic acid.

CONCLUSIONS

Future research is needed to better understand whether diabetes control and prevention can modulate OA occurrence and progression. The selection of therapy to treat OA symptoms in patients with T2DM may require careful consideration of the evidence based to avoid untoward safety issues.

Biochemical Markers for the Early Identification of Osteoarthritis: Systematic Review and Meta-Analysis

BACKGROUND

There is a desperate need for the reliable detection of osteoarthritis (OA) at the early stage when patients are likely to benefit most from disease interventions. A variety of biochemical markers have been proposed, but their reliability varies among studies.

OBJECTIVE

In this review, we aimed to answer the following questions: (1) are there biochemical markers that are differentially expressed in early OA versus healthy subjects, and (2) if so, what is the diagnostic value of these biomarkers for early OA?

METHODS

Embase, PubMed, and Web of Science were searched to obtain all relevant studies up to March 2018, and studies comparing the biochemical markers between early OA and healthy controls were selected. The Downs and Black checklist was used to assess the risk of bias. Biomarkers that were investigated in five or more different populations were pooled for meta-analysis. A meta-regression analysis was performed to explore possible explanations for the heterogeneity of studies.

RESULT

In total, 26 articles met the criteria for the qualitative synthesis and 17 articles for the final quantitative synthesis. N-terminal crosslinked telopeptide of type I collagen (NTX-I) was the only biomarker found to be differently expressed in patients with early OA versus controls, without significant heterogeneity among studies (I2 = 0%, [Formula: see text] = 1.695, p = 0.792). The meta-regression analysis identified that sample size and affected joint possibly explained the heterogeneity among studies.

CONCLUSION

Although a wide range of biomarkers has been previously investigated in early OA, the diagnostic value of these biomarkers could not be determined because due to a low number of studies regarding any given biomarker. Large prospective and adequately powered studies are therefore required to validate these (and other) biomarkers for identifying early OA.

Age-dependent Changes in Plasma Amino Acids Contribute to Alterations in Glycoxidation Products

BACKGROUND

Glycative stress is involved in the pathogenesis of various degenerative disorders. This study sought to determine the effect of age-related changes in amino acids on serum levels of pentosidine and carboxymethyl-lysine (CML) in healthy individuals.

METHODS

The subjects were 78 healthy individuals categorized into three age groups. The ages of the groups were as follows: 26 young adults (20-30 y, 25.2±3.03), 26 middle-aged adults (35-50 y, 39.46±6.97) and 26 older adults (60 y or older, 69.80±10.01). Serum levels of pentosidine and CML were measured by ELISA and levels of plasma amino acids were determined using HPLC.

RESULTS

Serum levels of pentosidine and CML in the youngest group were higher than in the oldest group (p=0.026, 0.029, respectively). There was a positive correlation between the serum levels of pentosidine and CML and the levels of plasmaTyrosine (p=0.032, r=0.211 and p=0.037, r=0.224), Valine (p=0.037, r=0.224 and p=0.021, r=0.247) and Isoleucine (p=0.041, r=0.203 and p=0.021, r=0.247), respectively. Serum levels of pentosidine and CML may be modulated by the plasma levels of selected amino acids.

CONCLUSIONS

Better understanding of the role of these selective amino acids might provide new perception of how glycation pathways may be altered and pave the way for new therapeutic principles.

Sex differences in the association of skin advanced glycation endproducts with knee osteoarthritis progression

Background

The accumulation of advanced glycation endproducts in articular cartilage has been suggested as an etiologic factor in the development and progression of knee osteoarthritis (KOA).

Methods

We conducted a prospective cohort study of skin advanced glycation endproducts (sAGEs) measured non-invasively by skin intrinsic fluorescence and the relationship between sAGE KOA progression in 160 men and 287 women in a sub-cohort of the Osteoarthritis Initiative at a single site. KOA progression was measured by yearly changes in Osteoarthritis Research Society International (OARSI)-defined joint space narrowing (JSN) and by yearly changes in joint space width (JSW) from baseline to 48 months. Sex-stratified repeated measures, mixed models to account for correlation between the knees within persons and adjusted for age, body mass index (BMI), Kellgren-Lawrence (KL) grade, beam angle and rim-to-rim distance were utilized.

Results

Increasing tertiles of sAGE measured at 36 months were associated with greater JSN over 4 years in men but not in women. The percentage of knees with JSN at 48 months, by tertiles of sAGE, were 7.0%, 16.0% and 17.7% in men (p for linear trend = 0.03) and 11.4%, 14.4% and 8.4% in women (p for linear trend = 0.33). Using change in JSW as the outcome, a similar trend was found in men but it was not statistically significant in fully adjusted models and no association was found in women.

Conclusion

This study provides preliminary evidence that sAGEs independent of age and BMI, are associated with knee JSN in men but not in women.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-017-1226-z) contains supplementary material, which is available to authorized users.

Serum pentosidine concentration is associated with radiographic severity of lumbar spondylosis in a general Japanese population

The aim of this study was to investigate the relationship between the radiographic severity of lumbar spondylosis (LS) and serum bone metabolic markers. A total of 681 individuals volunteered for this study (269 men, 412 women; age: 54.9 ± 14.3; body mass index [BMI]: 23.1 ± 3.3 kg/m²). Lateral lumbar radiographs were evaluated in each intervertebral section (L1/2 to L5/S1) using the Kellgren-Lawrence grade (KL). If at least one intervertebral section was graded as KL 2 or greater, the participants were considered to have LS. The summation of each section of intervertebral section was used as the radiographic severity value of LS. In addition, bone status was evaluated with an osteo-sono assessment index (OSI) at the calcaneus. Serum bone alkaline phosphatase (μg/mL), N-telopeptide of type I collagen (nMBCE/L), and pentosidine (pmol/mL) concentrations were examined and used as the bone metabolism index. Stepwise multiple linear regression analysis was conducted with the radiographic severity value of LS as the dependent variable and age, sex, BMI, OSI, and the value of serum bone metabolic markers as the independent variables. The total number of LS participants was 470 (69.0 %); the frequency of LS was higher in men (n = 198) than in women (n = 272; P = 0.036, χ ² test). The mean severity value of LS was 7.1 ± 4.4, and the mean value of pentosidine was 120.7 ± 54.8 pmol/mL. On multiple regression analysis, age (B = 0.190, β = 0.611), sex (men = 1, women = 2; B = -0.900, β = -0.099), BMI (B = 0.185, β = 0.136), and pentosidine (B = 0.009, β = 0.115) were significantly correlated with the severity of LS. Serum pentosidine concentration was positively correlated with the radiographic severity of LS in this cross-sectional study.

Biomarkers for osteoarthritis: Can they be used for risk assessment? A systematic review

The identification of early biochemical predictors of osteoarthritis (OA) has been the focus of much research over the past few years. However, it still is unclear whether current biochemical markers can be used in prognostic risk assessment of OA. The aim of this systematic review is to evaluate the possible prognostic application of blood and urinary biochemical markers of knee and hip OA. Abstract and full text selection was done by two independent reviewers. A total of 25 relevant publications including 37 biochemical markers of bone and cartilage turnover and inflammation associated with some aspects of OA were reviewed. Most of those biomarkers were studied only once or twice. Due to heterogeneity of both OA-phenotype and determinant among the publications, meta-analysis of the studied biochemical markers was not possible. There was strong evidence for urinary C-terminal telopeptide of collagen type II (uCTX-II) as a prognostic marker for knee OA progression and serum cartilage oligomeric protein (COMP) level as prognostic marker for incidence of knee and hip OA. Evidence for prognostic value of C-reactive protein is still inconclusive. International standardization of future investigations should be pursued to obtain more high-quality, homogenous data on the full spectrum of biochemical OA markers.

Alarmins S100A8/S100A9 aggravate osteophyte formation in experimental osteoarthritis and predict osteophyte progression in early human symptomatic osteoarthritis

OBJECTIVE

Alarmins S100A8 and S100A9 are major products of activated macrophages regulating cartilage damage and synovial activation during murine and human osteoarthritis (OA). In the current study, we investigated whether S100A8 and S100A9 are involved in osteophyte formation during experimental OA and whether S100A8/A9 predicts osteophyte progression in early human OA.

METHODS

OA was elicited in S100A9-/- mice in two experimental models that differ in degree of synovial activation. Osteophyte size, S100A8, S100A9 and VDIPEN neoepitope was measured histologically. Chondrogenesis was induced in murine mesenchymal stem cells in the presence of S100A8. Levels of S100A8/A9 were determined in plasma of early symptomatic OA participants of the Cohort Hip and Cohort Knee (CHECK) cohort study and osteophytes measured after 2 and 5 years.

RESULTS

Osteophyte size was drastically reduced in S100A9-/- mice in ligaments and at medial femur and tibia on days 21 and 42 of collagenase-induced OA, in which synovial activation is high. In contrast, osteophyte size was not reduced in S100A9-/- mice during destabilised medial meniscus OA, in which synovial activation is scant. S100A8 increased expression and activation of matrix metalloproteinases during micromass chondrogenesis, thereby possibly increasing cartilage matrix remodelling allowing for larger osteophytes. Interestingly, early symptomatic OA participants of the CHECK study with osteophyte progression after 2 and 5 years had elevated S100A8/A9 plasma levels at baseline, while C-reactive protein, erythrocyte sedimentation rate and cartilage oligomeric matrix protein were not elevated at baseline.

CONCLUSIONS

S100A8/A9 aggravate osteophyte formation in experimental OA with high synovial activation and may be used to predict osteophyte progression in early symptomatic human OA.