[Association between red blood cell volume distribution width and osteophytes: A cross-sectional study].

OBJECTIVE: To investigate the association between red blood cell volume distribution width (RDW) and osteophytes.
 Methods: This cross-sectional study was conducted in the Department of Health Examination Center of Xiangya Hospital, Central South University in Changsha, Hunan Province, China. A total of 8 334 subjects were included in this study. The severity of osteophytes was graded using the criteria of the Osteoarthritis Research Society International (OARSI). Osteophytes incident was defined as at least one side of the knee had a osteophytes grade ≥1. According to the quartiles of the RDW level, the subjects were divided into 4 groups. Multivariate logistic regression analysis was used to calculate the odds ratio (OR) and the 95% confidence interval (CI) of the knee osteophytes incidence between each RDW group and the lowest level group. Tests for linear trends were conducted based on logistic regression using a median variable of RDW level in each category.
 Results: Quartile 1 (Q1), RDW≤9.78; Q2, 9.7813.10. The multivariable adjusted ORs (95%CI) of the prevalence of osteophytes were 1.38 (1.06 to 1.79) in the second percentile interval, and 1.27 (0.97 to 1.66) and 1.50 (1.15 to 1.94) in the third and fourth percentile interval, respectively. Test for linear trends suggested that there was a positive association between the RDW level and the risk of knee osteophytes incidence (P=0.019).
 Conclusion: The risk of osteophytes incidence increases with the increasing RDW levels.

High level of functional dickkopf-1 predicts protection from syndesmophyte formation in patients with ankylosing spondylitis.

INTRODUCTION: The molecular mechanisms of syndesmophyte formation in ankylosing spondylitis (AS) are yet to be characterised. Molecules involved in bone formation such as Wnt proteins and their antagonists probably drive syndesmophyte formation in AS. METHODS: This study investigated sequential serum levels of functional dickkopf-1 (Dkk1), a potent Wnt antagonist involved in bone formation in arthritis, by capture ELISA with its receptor LRP6 in 65 AS patients from the German Spondyloarthritis Inception Cohort. Dkk1 levels were then related to structural progression (syndesmophyte formation) as well as sclerostin and C-reactive protein (CRP) levels. RESULTS: Functional Dkk1 levels were significantly (p=0.025) higher in patients with no syndesmophyte growth (6.78 ± 5.48 pg/ml) compared with those with syndesmophyte growth (4.13 ± 2.10 pg/ml). Dkk1 levels were highly correlated to serum sclerostin levels (r=0.71, 95% CI 0.53 to 0.82; p<0.001) but not to CRP (r=0.15, 95% CI -0.10 to 0.38; p=0.23). CONCLUSION: AS patients with no syndesmophyte formation show significantly higher functional Dkk1 levels suggesting that blunted Wnt signalling suppresses new bone formation and consequently syndesmophyte growth and spinal ankylosis. Similar to serum sclerostin levels, the functional Dkk1 level thus emerges as a potential biomarker for structural progression in patients with AS.

Sex dimorphism in the association of cardiometabolic characteristics and osteophytes-defined radiographic knee osteoarthritis among obese and non-obese adults: NHANES III.

OBJECTIVE: To examine the relationship of knee osteoarthritis (OA) with cardiovascular and metabolic risk factors by obesity status and gender. METHODS: Data from 1,066 National Health and Nutrition Examination Survey III participants (≥60 years of age) was used to examine relationships of osteophytes-defined radiographic knee OA and cardiovascular and metabolic measures. Analyses were considered among obese [body mass index (BMI)≥30 kg/m(2)] and non-obese (BMI<30 kg/m(2)) men and women. RESULTS: The prevalence of osteophytes-defined radiographic knee OA was 34%. Leptin levels and homeostatic model assessment-insulin resistance (HOMA-IR), a proxy measure of insulin resistance, were significantly associated with knee OA; those with knee OA had 35% higher HOMA-IR values and 52% higher leptin levels compared to those without knee OA. The magnitude of the association between HOMA-IR and knee OA was strongest among men, regardless of obesity status; odds ratios (ORs) for HOMA-IR were 34% greater among non-obese men (OR=1.18) vs obese women (OR=0.88). Among obese women, a 5-µg/L higher leptin was associated with nearly 30% higher odds of having knee OA (OR=1.28). Among men, ORs for the association of leptin and knee OA were in the opposite direction. CONCLUSIONS: Cardiometabolic dysfunction is related to osteophytes-defined radiographic knee OA prevalence and persists within subgroups defined by obesity status and gender. A sex dimorphism in the direction and magnitude of cardiometabolic risk factors with respect to knee OA was described including HOMA-IR being associated with OA prevalence among men while leptin levels were most important among women.

Large enthesophytes in teenage skulls: Mechanical, inflammatory and genetic considerations.

BACKGROUND: The literature implies that large enthesophytes are exclusive to genetically predisposed individuals and to Spondyloarthropathies sufferers. Accordingly, the aim of this investigation and report was to assess the involvement of genetic predisposition, inflammatory and/or mechanical influences in the development of large enthesophytes in a sample population of teenagers presenting with large enthesophytes emanating from the external occipital protuberance. METHODS: Analysis was based on four teenage males (13-16 year-old) possessing 14.5-30.5 mm enthesophytes projecting from the external occipital protuberance. This study included assessment of radiographs, MRI scans, blood-work, history, the SF-36 health survey, and the comparison of these data with the relevant literature to describe the interrelationships between the presence of enlarged external occipital protuberance, forward head protraction, active inflammation and/or genetic factors. FINDINGS: Known genetic markers (e.g. HLA-B27) were not detected by allele-specific primers and both ESR and CRP tests were negative. Additionally, MRI analyses failed to detect active localised inflammation at the external occipital protuberance and surrounding structures. The health survey yielded normal parameters for all participants. All participants displayed significantly large Forward Head Protraction values (>40 mm), and interviews with participants and their parents indicated that concerns related to posture were prevalent since early childhood. INTERPRETATION: This report suggests that mechanical load has an important role in enthesophyte development, irrespective the involvement of inflammatory or genetic factors.

Distinct impacts of syndesmophyte formation on male and female patients with ankylosing spondylitis.

AIM: Ankylosing spondylitis (AS), a chronic inflammatory autoimmune disease, mainly affects the axial skeleton, leading to sacroiliitis and rigidity of the spine. Both spinal rigidity and syndesmophyte development can affect bone formation and resorption. In addition, inflammatory cytokines and cell adhesion molecules are correlated with bone metabolism. The aim of this study was to investigate the effects of gender difference and syndesmophyte formation on cytokines, adhesion molecules and bone metabolism markers in AS patients. METHOD: Eighty-seven AS patients (68 males, 19 females) were enrolled in this study. Electrochemiluminescence immunoassay and enzyme-linked immunosorbent assay were performed to measure studied parameters. RESULTS: Regarding gender, the serum levels of C-terminal crosslinking telopeptide of type I collagen (CTX), vascular endothelial growth factor, soluble vascular cell adhesion molecule-1, tumor necrosis factor alpha and interleukin (IL)-18 in male patients were all significantly higher than those in female patients. The serum levels of osteocalcin and type I procollagen N-terminal propeptide showed downward trends, whereas CTX and parathyroid hormone concentrations were remarkably lower and IL-18 levels were significantly higher in male AS patients with syndesmophytes compared to those without syndesmophytes. In female patients, CTX and IL-6 levels in those with syndesmophytes were significantly higher than in those without syndesmophytes. Cytokines, adhesion molecules and bone metabolism markers were all positively related with syndesmophyte formation and gender differences. CONCLUSION: AS patients with syndesmophytes experienced imbalance of bone metabolism due to inflammatory cytokine release. Male AS patients had high levels of bone resorption markers, cytokines and adhesion molecules, reflecting a disorder of bone metabolism.

The effect of ß-carotene on lumbar osteophyte formation.

STUDY DESIGN: Cross-sectional cohort study of elderly people. OBJECTIVE: The relationships of osteophyte formation on plain lumbar radiographs with serum levels of antioxidants (carotenoids, vitamin A, vitamin E) and other factors were investigated to examine whether antioxidants are involved in lumbar spine degeneration. SUMMARY OF BACKGROUND DATA: Antioxidants have inhibitory effects on the onset of many diseases. However, the association of lumbar osteophyte formation with antioxidant levels in the general population has not been investigated. METHODS: The subjects were 286 people (103 men and 183 women; mean age = 68 years) who underwent resident health screening. Osteophyte formation on lumbar lateral radiographs (Nathan classification), lumbar lordosis angles, sacral inclination angles, serum levels of antioxidants, triglyceride levels, body mass index, osteoporosis, back muscle strength, history of alcohol intake, and smoking history were studied in these subjects. RESULTS: Lumbar osteophyte formation was detected in 48 subjects (17%). Osteophyte formation was significantly more common in elderly persons, men, and subjects with a history of alcohol intake; and had a significant correlation with sacral inclination angle. The levels of α-tocopherol, ß-tocopherol, zeaxanthin/lutein, cryptoxanthin, lycopene, α-carotene, and ß-carotene were significantly lower in subjects with osteophytes. Logistic regression analysis adjusted for all factors showed that a higher age (odds ratio [OR] = 1.1, 95% confidence interval [CI] = 1.02-1.16; P = 0.02) and a low ß-carotene level (OR = 6.7, 95% CI = 1.39-32.6; P = 0.02) were risk factors for osteophyte formation. CONCLUSION: The serum levels of carotenoids and vitamin E were significantly lower in subjects with lumbar osteophyte formation, and a low ß-carotene level was the strongest risk factor for lumbar osteophytes. This is the first evidence of an association between carotenoids and lumbar osteophyte formation. This finding suggests that appropriate dietary intake of antioxidants is important for inhibition of lumbar spine degeneration in a rapidly aging society.