Serum keratan sulfate is a promising marker of early articular cartilage breakdown

OBJECTIVES: To find serum markers that may serve as indices for an early diagnosis of degeneration or damage of the articular cartilage. METHODS: Twenty-four healthy volunteers, 19 individuals with knee trauma (KT) and 31 with knee osteoarthritis (OA) were evaluated. KT patients were divided into a group (n = 5) with an injury <2 months old (recent KT) and a group (n = 14) with that >2 months old (old KT). Articular cartilage damage was assessed using either arthroscopy or direct observation. Serum concentrations of hyaluronic acid (HA), cartilage proteoglycan aggrecan turnover epitope (CS846) and cartilage oligomeric protein (COMP) were measured using enzyme-linked immunosorbent assay kits and those of keratan sulfate (KS) and chondroitin-6-sulfate (C6S) using high-performance liquid chromatography. RESULTS: Serum KS in the recent KT group (2095 +/- 594 ng/ml) was significantly higher than that in the old KT group (1373 +/- 418 ng/ml; P = 0.021), and serum COMP in the recent KT group (1572 +/- 182 ng/ml) showed a tendency that was higher than that in the old KT group (1350 +/- 250 ng/ml; P = 0.079). Serum KS in OA patients with Kellgren and Lawrence (KL) grades 0 and I (1456 +/- 334 ng/ml) showed a tendency that was higher than that in OA patients with KL grades II, III and IV (1248 +/- 220 ng/ml; P = 0.084). CONCLUSIONS: The serum concentration of KS correlated with the damage of the articular cartilage and it was significantly increased even at an early stage after the injury.     

Serum hyaluronan levels and radiographic knee and hip osteoarthritis in African Americans and Caucasians in the Johnston County Osteoarthritis Project

OBJECTIVE: Serum hyaluronan (HA) has been proposed as a potential biomarker of osteoarthritis (OA). We examined associations between serum HA and radiographic OA in an ethnically diverse, population-based sample. METHODS: Participants were selected from the Johnston County Osteoarthritis Project, using stratified simple random sampling to achieve balance according to radiographic knee OA status, ethnic group, sex, and age group. Serum HA was measured by enzyme-linked immunosorbent assay. Radiographic OA variables included knee OA, knee OA laterality, knee OA severity, concomitant knee and hip OA, and total number of OA-affected knee and hip joints. Analysis of covariance was used to assess differences in mean serum levels of natural log-transformed HA (ln serum HA) between groups, adjusting for ethnicity, sex, age, body mass index (BMI), and self-reported comorbidities. RESULTS: Levels of ln serum HA were positively associated with all definitions of radiographic OA (P < 0.0001). Levels of ln serum HA were higher in Caucasians (P = 0.0094) and in men (P = 0.0038) and were moderately correlated with age (r = 0.35, P < 0.0001). The associations with radiographic OA, ethnicity, sex, and age remained statistically significant after adjustment (P < 0.0045). There were no interactions between ethnicity and the other covariates. CONCLUSION: These cross-sectional data support a role for serum HA as a biomarker of radiographic OA. The variations in levels of serum HA attributable to ethnicity, sex, and age were not explained by radiographic OA, BMI, or comorbidities. The lack of strong confounding between serum HA and comorbidities further supports a role for serum HA as a potential biomarker.     

Suggestion of nonlinear or phasic progression of knee osteoarthritis based on measurements of serum cartilage oligomeric matrix protein levels over five years

OBJECTIVE: In many patients with knee osteoarthritis (OA), the disease progresses, and there is loss of cartilage; in others, the disease stabilizes with time. Previous studies have demonstrated that concentrations of serum proteins that reflect joint tissue metabolism can identify knees that will deteriorate, leading to the suggestion that OA disease activity is phasic or cyclical. The aim of the current study was to determine whether longitudinal measurements of one such protein, serum cartilage oligomeric matrix protein (COMP), are related to disease outcome over a 5-year period. METHODS: Serum COMP levels were measured by enzyme-linked immunosorbent assay at study entry and every 6 months thereafter in 115 patients with knee pain and OA of mainly the tibiofemoral joint. Cartilage loss was determined from knee radiographs taken at entry and at 24, 36, and 60 months. Disease progression was defined as either a reduction in the tibiofemoral joint space width by at least 2 mm or total knee replacement (TKR) in either knee at followup. COMP concentrations at baseline and the area under the curve (AUC) of measurements obtained over 5 years were compared between progressors and nonprogressors by Student's 2-tailed t-test. The patterns and probability of progression according to TKR or > or =2 mm of narrowing of the tibiofemoral joint space were analyzed by logistic regression models. RESULTS: The mean +/- SD ages of the progressors and nonprogressors were 64.2 +/- 7.8 years and 63.3 +/- 10.6 years, respectively, and the proportion of females was 51% and 56%, respectively. Of the 37 patients whose OA progressed (22 by TKR and 15 by > or =2-mm reduction in tibiofemoral joint space), 13 lost cartilage during the first 2 years, and 18 lost cartilage during the last 2 years. The mean +/- SD serum COMP concentration at baseline was significantly higher in the progressors compared with the nonprogressors (14.12 +/- 3.39 units/liter versus 12.62 +/- 3.25 units/liter; P < 0.036). Serum COMP levels rose significantly after TKR; however, after allowing for the effect of TKR, the AUC/month was significantly higher in the progressors compared with the nonprogressors (12.52 +/- 2.71 versus 10.82 +/- 2.71; P < 0.003). Serum COMP concentrations were higher during periods of radiographic progression and identified periods of progression that were nonlinear. Logistic regression analysis showed that on average, a 1-unit increase in serum COMP levels increased the probability of radiographic progression by 15%. CONCLUSION: The data suggest that serum COMP is related to progressive joint damage in knee OA. The patterns of progression for the early and late progressors are consistent with the hypothesis that knee OA progression is episodic or phasic. Large between-subject variation precludes the use of individual values to predict progression with confidence. However, sequential measurements of serum COMP levels may identify patients whose OA is likely to progress over the next year or two.     

Serum cartilage oligomeric matrix protein (COMP) levels in knee osteoarthritis in a Brazilian population: clinical and radiological correlation

OBJECTIVES: In this study we present data on serum cartilage oligomeric matrix protein (COMP) levels in a Brazilian population with isolated knee osteoarthritis (OA) compared to healthy controls. Clinical and radiological correlations with COMP levels were also evaluated. METHODS: Two hundred and seventy-two patients seen at the Rheumatology Division of the Federal University of S?o Paulo (UNIFESP) with a symptom of 'pain in the knees' for at least 3 months were invited to participate in this study. History and clinical examination were performed in all patients. Eighty-six patients with clinical isolated knee OA according to the American College of Rheumatology (ACR) criteria and without other causes of pain in the knee were included. Fifty-eight healthy individuals were selected, matched for age and sex, and used as controls. OA evaluation included Lequesne and Western Ontario and MacMaster Universities osteoarthritis index (WOMAC) questionnaires, visual analogue scale (VAS) for pain and standard knee X-rays. Blood samples were taken from all participants and serum COMP levels were measured by enzyme-linked immunosorbent assay (ELISA). OA radiological analysis was performed using the Kellgren and Lawrence (K/L) grading scale. RESULTS: Patients with symptomatic knee OA presented significantly higher serum COMP levels compared to healthy controls and to those with non-symptomatic narrowing of the articular space (p<0.001). Patients with clinical evidence of knee OA and without radiological abnormalities (K/L grade 0 or 1) had intermediate serum COMP levels, significantly higher than those observed in healthy controls (p<0.03). CONCLUSIONS: We observed increased serum COMP levels in patients with symptomatic radiological knee OA. High serum COMP levels may also indicate cartilage damage in selected symptomatic patients without significant radiological abnormalities.     

Positive association between serum 25-hydroxyvitamin D level and bone density in osteoarthritis

OBJECTIVE: To describe the association between serum 25-hydroxyvitamin D (25[OH]D) level and bone mineral density (BMD) in persons with primary knee osteoarthritis (OA). METHODS: We conducted a population-based survey of the Framingham Study. A total of 228 subjects with primary radiographic knee OA were identified. For vitamin D status, 25(OH)D levels < or =15 ng/ml were classified as vitamin D deficient, 25(OH)D levels 16-32 ng/ml were classified as hypovitaminosis D, and 25(OH)D levels >32 ng/ml were classified as vitamin D replete. We compared average BMD between categories of 25(OH)D levels in subjects with OA using a linear regression model while adjusting for sex, age, body mass index (BMI), knee pain, physical activity, cohort, and disease severity. RESULTS: Mean age was 74.4 years and 36% were men. Of 228 individuals, 15% were vitamin D deficient, 51% had hypovitaminosis D, and 34% were vitamin D replete. Compared with subjects with vitamin D deficiency, those with hypovitaminosis D had a 7.3% higher BMD (adjusted percent difference; P = 0.02) and vitamin D replete subjects had an 8.5% higher BMD (adjusted percent difference; P = 0.02; test for trend across categories: P = 0.04). CONCLUSION: We observed a significant positive association between serum 25(OH)D and BMD in individuals with primary knee OA, independent of sex, age, BMI, knee pain, physical activity, and disease severity. Given the high prevalence of low 25(OH)D status in persons with knee OA and the positive association between 25(OH)D and BMD, vitamin D supplementation may enhance BMD in individuals with OA.     

The heritable determinants of cartilage oligomeric matrix protein

OBJECTIVE: Cartilage oligomeric matrix protein (COMP) is a cartilage matrix macromolecule. The protein is detectable in serum and has been investigated as a biomarker of osteoarthritis (OA). An association between COMP and OA has been shown, yet the precise factors governing serum levels of COMP remain unclear. The aim of this study was to determine whether genetic factors influence serum levels of COMP. METHODS: A classic twin study was conducted using COMP levels in serum obtained from healthy female twin volunteers. COMP levels were determined by an inhibition enzyme-linked immunosorbent assay method. The heritability of COMP was determined by comparing correlation among 160 monozygotic and 349 dizygotic twin pairs. Data on potential confounding factors, including age, body mass index, and the presence of OA as assessed by hand, hip, and knee radiographs, were included in the analysis. RESULTS: Serum levels of COMP showed a correlation of 0.72 (95% confidence interval [95% CI] 0.65-0.80) among monozygotic twin pairs and 0.47 (95% CI 0.39-0.55) in dizygotic pairs. This equated to an estimated heritability for COMP of 40% (95% CI 20-60%). Although age and body mass index were found to be significantly associated with COMP in regression analysis, taking the effects of these factors into account did not influence the estimate of heritability. CONCLUSION: This study showed that heritable factors influence serum levels of the cartilage matrix biomarker COMP. Together with other published data, the results suggest that genetic factors operate at an early stage in the etiologic pathways that influence the development of radiographically discernible OA.     

High CCL18/PARC expression in articular cartilage and synovial tissue of patients with rheumatoid arthritis

OBJECTIVE: We studied the role of CCL18/pulmonary and activation-regulated chemokine (PARC) in rheumatoid arthritis (RA). METHODS: Human cartilage tissues and synovial membranes were obtained from patients with RA and with osteoarthritis (OA). Sera samples were obtained from RA patients, OA patients, healthy controls, and patients with flu, and synovial fluid (SF) from patients with RA and OA. Real-time PCR was performed with RNA from cartilage samples. Immunohistochemical analysis of CCL18/PARC was done with RA and OA cartilage and synovial tissue. Levels of CCL18/PARC in serum and SF were evaluated by ELISA. RESULTS: CCL18/PARC mRNA was expressed at significantly higher levels in RA cartilage than in OA (p = 0.0001) and control (p < 0.0001) samples. CCL18/PARC mRNA expression was much higher in RA synovial membrane than OA samples (p = 0.0001). All RA cartilage and synovial tissue samples exhibited medium to strong staining for CCL18/PARC. Serum levels of CCL18/PARC were higher in RA patients (156.21 +/- 125.73 ng/ml, n = 71) than in OA patients (64.54 +/- 40.90 ng/ml, n = 12) and controls (28.04 +/- 10.96 ng/ml, n = 20). Levels of CCL18/PARC in RA SF (275.20 +/- 228.16 ng/ml, n = 15) were higher than in OA (33.13 +/- 14.84 ng/ml, n = 6; p = 0.0198). CCL18/PARC levels correlated significantly with rheumatoid factor levels (r = 0.431, p = 0.0040), but not with matrix metalloproteinase-3, erythrocyte sedimentation rate, and C-reactive protein. CONCLUSION: CCL18/PARC was highly expressed in RA articular cartilage and synovial tissue compared with OA samples. Our data indicated that CCL18/PARC levels are not related to the conditions of generalized inflammation, but are related to the pathogenesis of RA.     

Cartilage oligomeric matrix protein increases in serum after the start of growth hormone treatment in prepubertal children

Both GH and IGF-I stimulate bone growth, but the molecular mechanisms mediating their effects on the growth plate are not fully understood. We measured gene expression by microarray analysis in primary cultured human chondrocytes treated with either GH or IGF-I. One of the genes found to be up-regulated by both GH and IGF-I was that encoding cartilage oligomeric matrix protein (COMP). This protein is predominantly found in the extracellular matrix of cartilage. Mutations in the COMP gene have been associated with syndromes of short stature. To verify that COMP is regulated by GH in vivo, we measured COMP levels in serum in short children treated with GH. The study included 113 short prepubertal children (14 girls and 99 boys) with a mean (+/- sd) age of 8.84 +/- 2.76 yr, height sd score of -2.74 +/- 0.67, and IGF-I sd score of -1.21 +/- 1.07 at the start of GH administration. Serum levels of COMP were 1.58 +/- 0.28, 1.83 +/- 0.28 (P < 0.0001), 1.91 +/- 0.28 (P < 0.0001), 1.78 +/- 0.28 (P < 0.001), and 1.70 +/- 0.24 (P < 0.05) microg/ml at baseline and after 1 wk and 1, 3, and 12 months, respectively.In conclusion, we have demonstrated that COMP expression is up-regulated by both GH and IGF-I in primary cultured human chondrocytes. Furthermore, serum levels of COMP increase after the start of GH treatment in short children.     

Serum insulin-like growth factor-I (IGF-I) IGF binding protein-3 (IGFBP-3) and leptin levels are related to abdominal aortic intima-media thickness in macrosomic newborns.

OBJECTIVE: Exposure to diabetes in utero has been established as a significant risk factor for some of the components of metabolic syndrome, and was associated with increased levels of maternal, placental, and fetal insulin-like growth factors and leptin. The atherogenic effects of leptin and insulin-like growth factor-I (IGF-I) have been extensively described. The present study was therefore designed to investigate relationships between abdominal aortic intima-media thickness (aIMT), serum IGF-I, IGF binding protein-3 (IGFBP-3) and leptin levels in macrosomic newborns. DESIGN: Neonates whose birth weights exceed 90th percentile for gestational age and gender are termed macrosomic. Abdominal aortic intima-media thickness was measured in 30 macrosomic neonates of diabetic mothers (group A), 30 macrosomic neonates of healthy mothers (group B) and 30 healthy neonates (group C). Serum IGF-I, IGFBP-3 and leptin levels were determined in all infants and their mothers. Stepwise logistic regression analysis was used to determine independent risk factors for aortic intima-media thickness. RESULTS: Mean aortic intima-media thickness was significantly higher in groups A and B (0.489+/-0.015,0.466+/-0.019 mm, respectively) than in controls (0.375+/-0.024 mm, p<0.0001). Weight-adjusted aortic intima-media thickness was significantly higher in-group A than in groups B (p=0.004) and C (p=0.048). Serum leptin concentration in-group B (37.4+/-10.7 ng/ml) was significantly greater than in-group C (23.5+/-7.1 ng/ml, p<0.0001), but significantly lower than in-group A (46.6+/-14.1 ng/ml, p<0.0001). Serum IGF-I levels of the infants were significantly lower in-group C (113.2+/-33.1 ng/ml) than in groups A and B (205.2+/-60.1 and 179.3+/-55.1 ng/ml respectively, p<0.0001). Serum IGF-I, IGFBP-3 and leptin levels of the infants were positively correlated with mean (p<0.0001) and weight-adjusted aortic intima-media thickness measurements (p=0.003, p=0.006 and p=0.001, respectively). CONCLUSIONS: Macrosomic neonates of diabetic mothers have significantly increased aortic intima-media thickness with higher serum IGF-I, IGFBP-3 and leptin concentrations than those of controls. It might be speculated that these changes may exaggerate the atherosclerotic process later in life.     

Whole‐body bone scintigraphy provides a measure of the total‐body burden of osteoarthritis for the purpose of systemic biomarker validation

Objective

To evaluate the association of serum and synovial fluid cartilage oligomeric matrix protein (COMP) with systemic and local measures of osteoarthritis (OA) activity by bone scintigraphy.

Methods

Samples of serum and knee joint synovial fluid (275 knees) were obtained from 159 patients with symptomatic OA of at least 1 knee. Bone scintigraphy using ^99mTc‐labeled methylene diphosphonate was performed, and early‐phase knee scans and late‐phase whole‐body bone scans of 15 additional joint sites were scored semiquantitatively. To control for within‐subject correlations of knee data, generalized linear modeling was used in the correlation of the bone scan scores with the COMP levels. Principal components analysis was used to explore the contribution of each joint site to the variance in serum COMP levels.

Results

The correlation between synovial fluid and serum COMP levels was significant (r = 0.206, P = 0.006). Synovial fluid COMP levels correlated most strongly with the early‐phase knee bone scan scores (P = 0.0003), even after adjustment for OA severity according to the late‐phase bone scan scores (P = 0.015), as well as synovial fluid volumes (P < 0.0001). Serum COMP levels correlated with the total‐body bone scan scores (r = 0.188, P = 0.018) and with a factor composed of the bone scan scores in the shoulders, spine, lateral knees, and sacroiliac joints (P = 0.0004).

Conclusion

Synovial fluid COMP levels correlated strongly with 2 indicators of knee joint inflammation: early‐phase bone scintigraphic findings and synovial fluid volume. Serum COMP levels correlated with total‐body joint disease severity as determined by late‐phase bone scintigraphy, supporting the hypothesis that whole‐body bone scintigraphy is a means of quantifying the total‐body burden of OA for systemic biomarker validation.

     

The use of intravenous catheterisation with a rest period is useful for determination of plasma cortisol levels but not plasma prolactin levels

OBJECTIVE: The use of an intravenous catheter with a rest period has been recommended to avoid false-positive results for hyperprolactinaemia and false-negative results for hypocortisolaemia. We tested the relevance of this recommendation. DESIGN: Plasma cortisol and prolactin levels were determined before (T-15) and after a 15-min rest period (T0) in 119 patients, 38 males (M) and 81 females (F). 52 of the 119 patients were known (K; 30 females and 22 males) and 67 unknown (UK; 49 females and 18 males) to the unit. RESULTS: Prolactin was lower after rest in women (12.3+/-22.7 ng/l vs 11.7+/-22.5 ng/ml, P=0.03), but not in men (6.2+/-4.5 ng/ml at T-15 vs 5.8+/-3.2 ng/ml at T0, P=0.09), in the UK subgroup (10.6+/-20.7 ng/ml at T-15 vs 10.1+/-20.9 ng/ml at T0, P=0.06) and in the K subgroup (10.1+/-16.7 ng/ml at T-15 vs 9.7+/-15.8 ng/ml at T0, P=0.08). None of the patients with prolactin levels higher than 20 ng/ml at T-15 diminished its prolactin value below this cut-off value. Plasma cortisol levels were lower after rest in women (17.9+/-5.9 microg/dl at T-15 vs 16.5+/-6.1 microg/dl at T0, P<0.0001), in the UK subgroup (18+/-6.1 microg/dl at T-15 vs 16.6+/-6.4 microg/dl at T0, P=0.0003) but not in men (18+/-4.4 microg/dl at T-15 vs 17.5+/-5.8 microg/dl at T0, P=0.47) and in the K subgroup (17.8+/-4.6 microg/dl at T-15 vs 17+/-5.4 microg/dl at T0, P=0.13). At T0, 3.3% and 15% of patients presented values below the cut-off value of 10 microg/dl (276 nmol/l) and 17 microg/dl (470 nmol/l), respectively. CONCLUSION: These results don't justify intravenous catheterisation with a rest period for plasma prolactin determination in contrast with plasma cortisol determination.     

Uncoupling of type II collagen synthesis and degradation predicts progression of joint damage in patients with knee osteoarthritis

OBJECTIVE: The hallmark of osteoarthritis (OA) is the loss of articular cartilage. This loss arises from an imbalance between cartilage synthesis and cartilage degradation over a variable period of time. The aims of this study were to investigate the rates of these processes in patients with knee OA using two new molecular markers and to investigate whether the combined use of these markers could predict the progression of joint damage evaluated by both radiography and arthroscopy of the joints during a period of 1 year. METHODS: Seventy-five patients with medial knee OA (51 women, 24 men; mean +/- SD age 63 +/- 8 years, mean +/- SD disease duration 4.8 +/- 5.2 years) were studied prospectively. At baseline, we measured serum levels of N-propeptide of type IIA procollagen (PIIANP) and urinary excretion of C-terminal crosslinking telopeptide of type II collagen (CTX-II) as markers of type II collagen synthesis and degradation, respectively. Joint space width (JSW) on radiography and medial chondropathy at arthroscopy (assessed using a 100-mm visual analog scale [VAS]) were measured in all patients at baseline and in 52 patients at 1 year. Progression of joint destruction was defined as a decrease of > or =0.5 mm in JSW on radiography and as increased chondropathy (an increase in the VAS score of >8.0 units) between the baseline and 1-year evaluations. RESULTS: At baseline, compared with 58 healthy age- and sex-matched controls, patients with knee OA had decreased serum levels of PIIANP (20 ng/ml versus 29 ng/ml; P < 0.001) and increased urinary excretion of CTX-II (618 ng/mmole creatinine [Cr] versus 367 ng/mmole Cr; P < 0.001). The highest discrimination between OA patients and controls was obtained by combining PIIANP and CTX-II in an uncoupling index (Z score CTX-II - Z score PIIANP), which yielded a mean Z score of 2.9 (P < 0.0001). Increased baseline values in the uncoupling index were associated with greater progression of joint damage evaluated either by changes in JSW (r = -0.46, P = 0.0016) or by VAS score (r = 0.36, P = 0.014). Patients with both low levels of PIIANP (less than or equal to the mean - 1 SD in controls) and high levels of CTX-II (greater than or equal to the mean + 1 SD in controls) had an 8-fold more rapid progression of joint damage than other patients (P = 0.012 and P < 0.0001 as assessed by radiography and arthroscopy, respectively) and had relative risks of progression of 2.9 (95% confidence interval [95% CI] 0.80-11.1) and 9.3 (95% CI 2.2-39) by radiography and arthroscopy, respectively. CONCLUSION: Patients with knee OA are characterized by an uncoupling of type II collagen synthesis and degradation which can be detected by assays for serum PIIANP and urinary CTX-II. The combination of these two new markers could be useful for identifying knee OA patients at high risk for rapid progression of joint damage.     

Risk factors for progression of lumbar spine disc degeneration: the Chingford Study

OBJECTIVE: Few data exist concerning the natural history of lumbar spine disc degeneration and associated risk factors. We therefore undertook this study to examine the radiographic progression of lumbar spine disc degeneration over the course of 9 years in a population-based inception cohort of women from the Chingford Study. METHODS: Seven hundred ninety-six paired lumbar spine radiographs were read by a single reader for anterior osteophytes (AO) and disc space narrowing (DSN) using the Lane atlas at each lumbar disc space (L1-5). Disc degeneration was defined using thresholds of AO and DSN grade 1+ in one or more vertebrae (L1-5) within a subject. Progression was defined as an increase in grade in an affected year-1 vertebra. Potential risk factors were assessed using odds ratios and 95% confidence intervals adjusted for age, body mass index (BMI), and other potential confounders in logistic regression models using the STATA statistical package. RESULTS: The mean +/- SD age at baseline was 53.8 +/- 6.0 years, and mean +/- SD BMI was 25.4 +/- 4.1 kg/m(2). Progression rates for AO and DSN were 4% per annum and 3% per annum, respectively. Progression of DSN was predicted by age, back pain, and radiographic hip and knee osteoarthritis (OA). Progression of AO was predicted by age and radiographic hip OA, with borderline significance for BMI >30 kg/m(2). No significant effects were seen for smoking, physical activity, hormone replacement therapy use, multiparity, or hand OA. CONCLUSION: This is the first population-based longitudinal study to assess progression of the individual radiographic features of AO and DSN in lumbar spine disc degeneration. We demonstrated progression rates of 3-4% per annum, with important risk factors for progression, including age, back pain, and radiographic OA at the hip and knee.     

Early increase of oxidative stress and soluble CD40L in children with hypercholesterolemia.

OBJECTIVES: The aim of the study was to analyze the behavior of oxidative stress and its interplay with CD40L, a protein that is implicated in atherosclerosis, in hypercholesterolemic children. BACKGROUND: Oxidative stress has been suggested to play a major role in premature atherosclerosis. METHODS: Forty-one children with hypercholesterolemia (mean age 9.28 +/- 0.5 years) and 40 children with normocholesterolemia (mean age 9.02 +/- 0.69 years) were matched for gender and age. Within each group, children were classified as having or not having a family history of cardiovascular disease. Serum levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative stress, and plasma levels of soluble CD40L (sCD40L) were measured in each child. In a subgroup of children with high (n = 8) or normal (n = 8) levels of serum cholesterol, platelet p38 mitogen-activated protein (MAP) kinase phosphorylation, a protein involved in the activation of nicotinamide adenine dinucleotide phosphate oxidase, was determined. RESULTS: Children with hypercholesterolemia had higher values of 8-OHdG and sCD40L compared with control subjects (0.55 +/- 0.06 ng/ml vs. 0.21 +/- 0.02 ng/ml, p < 0.001 and 0.55 +/- 0.04 ng/ml vs. 0.19 +/- 0.03 ng/ml, p < 0.001, respectively). A significant correlation between 8-OHdG and sCD40L was observed in children with high (r = 0.676, p < 0.001) or normal (r = 0.878, p < 0.001) levels of cholesterol. Children with a family history of cardiovascular disease tended to have higher values of 8-OHdG and sCD40L, but the difference was not significant. Analysis of platelet p38 MAP kinase showed that it was phosphorylated more in children with hypercholesterolemia compared with control subjects (36.8 +/- 5.8 AU vs. 8.0 +/- 4.5 AU, p < 0.001 respectively). CONCLUSIONS: Children with hypercholesterolemia have an early increase of oxidative stress that may be responsible for up-regulation of CD40L and potentially predispose to premature atherosclerosis.     

Increased leptin concentrations and lack of gender difference in Type 2 diabetic patients with nephropathy

Leptin plays an important role in the regulation of body weight and energy balance. Women have higher circulating leptin level than men. In this study, we examined serum leptin concentrations in Type 2 diabetic men and women with or without nephropathy. Fasting plasma glucose (FPG), lipid profile, and serum leptin concentrations were measured in 34 Type 2 diabetic patients with nephropathy (DMN), 12 normoalbuminuric Type 2 diabetic subjects (DM) and 34 non-diabetic control subjects, all matched for age and body mass index (BMI). RESULT: Patients with diabetic nephropathy had lower high-density lipoprotein cholesterol and higher triglyceride, FPG, urinary albumin/creatinine ratio (ACR) and serum creatinine than the other two groups. There was a significant trend in serum leptin concentrations (P<0.001, analysis of variance ANOVA) across the three groups with the main difference being detected between DMN and control subjects (DMN: 17.5 +/- 16.8 ng/ml, DM: 14.6 +/- 10.5 ng/ml and control: 9.1 +/- 7.1 ng/ml). Women had higher serum leptin concentration than men in the control group (12.5 +/- 7.3 ng/ml versus 4.2 +/- 2.0 ng/ml, P=0.001) and in the DM group (18.9 +/- 11 ng/ml versus 8.6 +/- 5.9 ng/ml, P=0.07) whereas this gender difference was not observed in the DMN group (18.6 +/- 17.0 ng/ml versus 16.8 +/- 17.0 ng/ml, P=0.754). On multivariate analysis, ACR (=0.411, P<0.001) and BMI (=0.240, P=0.002) were independently associated with serum leptin concentrations (R2=0.194, F=22.1, P<0.001) in the whole group. In the DMN group, ACR (=0.370, P=0.016) was the only independent determinant of serum leptin concentrations (R2=0.159, F=11.4, P=0.016). Serum leptin concentrations were higher in Type 2 diabetic patients with nephropathy than normoalbuminuric diabetic patients and controls. Diabetic men with nephropathy had proportionally higher serum leptin such that the gender difference in leptin observed in non-nephropathic individuals was abolished.     

Cartilage and serum levels of nitric oxide in patients with hip osteoarthritis.

OBJECTIVE: To assess whether nitric oxide (NO) is related to cartilage deterioration resulting from osteoarthritis, NO concentrations were analyzed in normal and deteriorated areas of cartilage obtained from femur heads of patients with primary hip osteoarthritis (HOA). METHODS: The concentration of NO in macroscopically deteriorated and non-deteriorated cartilage of femoral heads of patients with HOA at hip replacement surgery was analyzed spectrophotometrically. Serum NO levels were also determined in 16 ambulatory patients with hip OA and in healthy volunteers. RESULTS: NO levels of non-deteriorated areas of femoral head cartilage were significantly lower (3.82+/-1.30 micromol/l; mean +/- SD) than levels of deteriorated cartilage areas (11.07+/-6.48 micromol/l; p<0.01). The surgery HOA group showed serum NO levels (2.64+/-0.32 micromol/l; p<0.0001 vs. healthy group) similar to the ambulatory HOA group levels (2.56+/-0.56 micromol/l; p<0.0001 vs. healthy group). Serum NO concentrations in healthy volunteers were 1.37+/-0.55 micromol/l. CONCLUSION: This study shows increased NO levels in joint cartilage of patients with hip OA. This increase was not homogeneously distributed, but the higher NO levels were found in macroscopically deteriorated areas. The data also suggest that high NO serum levels found in patients with hip OA may be due to joint cartilage destruction.     

Differences in serum sex hormone and plasma lipid levels in Caucasian and African-American premenopausal women

CONTEXT: Risk of coronary heart disease is higher in African-American than in Caucasian women. OBJECTIVE: The aim of this study was to evaluate the contribution of sex hormone levels, race, and measures of body fat to the variation in plasma lipid levels, a well-established risk factor for coronary heart disease. DESIGN: This was a cross-sectional study. SETTING: The study was conducted in the general community. STUDY PARTICIPANTS: Sixty Caucasian and 117 African-American premenopausal women participated. MAIN OUTCOME MEASURES: Body weight, body mass index (BMI), and waist to hip circumference ratio (WHR), as well as plasma lipid and serum sex hormone levels, were assessed. RESULTS: Relative to Caucasian women, African-American women had significantly higher mean BMI (23.92 +/- 3.87 vs. 26.99 +/- 5.87 kg/m2, respectively; P < 0.001), and WHR (0.733 +/- 0.052 vs. 0.757 +/- 0.068; P < 0.03). Also, plasma triglyceride (TG) levels were significantly lower in African-American women (81 +/- 61 vs. 55 +/- 24 mg/dl; P < 0.0001). Serum estrone sulfate (556 +/- 323 vs. 442 +/- 332 pg/ml, Caucasian vs. African-American; P < 0.001), estradiol (E2) (55.1 +/- 43.6 vs. 35.8 +/- 17.7 pg/ml; P < 0.0001), androstenedione (2.6 +/- 0.9 vs. 1.6 +/- 0.7 ng/ml; P < 0.0001), and testosterone (0.36 +/- 0.12 vs. 0.31 +/- 0.19 ng/ml; P < 0.002) levels were significantly lower in African-American women than in Caucasian women. After correction for the effects of age, BMI, and WHR, serum E2 levels were significantly and positively associated with plasma high-density lipoprotein cholesterol levels in all women, and serum estrone sulfate levels with plasma total cholesterol and TG levels in African-American women. CONCLUSIONS: Our results indicate that race is an important determinant of plasma TG and serum sex hormone levels, even after adjustment for differences in body size. A significant association between endogenous E2 and high-density lipoprotein cholesterol levels exists in premenopausal women, independent of their race.     

Association between alcohol consumption and serum dehydroepiandrosterone sulphate concentration in men with Type 2 diabetes: a link to decreased cardiovascular risk.

AIMS: Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in patients with Type 2 diabetes. Both light-to-moderate alcohol consumption and higher serum concentrations of dehydroepiandrosterone (DHEA) are associated with reduced CVD mortality, raising the possibility of DHEA as a causal intermediate in CVD and alcohol consumption. METHODS: Relationships between alcohol consumption and serum DHEA sulphate (DHEA-S) concentration, carotid atherosclerosis as evaluated by carotid ultrasonography and major cardiovascular risk factors were investigated in 404 consecutive men with Type 2 diabetes. Patients were divided into three groups according to mean ethanol consumption per week: non-drinkers, light-to-moderate drinkers (< 210 g per week) or heavy drinkers (> or = 210 g per week). RESULTS: Plasma HDL-cholesterol was positively associated with the degree of alcohol consumption. Intima-media thickness (0.92 +/- 0.21 vs. 1.09 +/- 0.35 mm, P < 0.0001) and plaque score (3.0 +/- 3.3 vs. 5.2 +/- 4.9, P = 0.008) were lower in light-to-moderate drinkers than in non-drinkers. Serum DHEA-S concentrations were higher in light-to-moderate drinkers (1264.2 +/- 592.2 ng/ml, P < 0.0001) and heavy drinkers (1176.2 +/- 607.6 ng/ml, P = 0.0100) than in non-drinkers (956.8 +/- 538.6 ng/ml). In a subgroup aged 60-75-year-old patients (n = 277), serum DHEA-S concentrations were higher in light-to-moderate drinkers (1126.8 +/- 502.5 ng/ml, P = 0.0121) than in non-drinkers (937.9 +/- 505.1 ng/ml). Also, in a subgroup without CVD (n = 339), serum DHEA-S concentrations were higher in light-to-moderate drinkers (1328.5 +/- 593.7 ng/ml, P < 0.0001) than in non-drinkers (970.1 +/- 540.7 ng/ml). CONCLUSIONS: Higher serum DHEA-S concentrations in light-to-moderate drinkers may represent part of the link between light-to-moderate alcohol consumption and lower CVD mortality.     

Serum concentrations of type II collagen biomarkers (C2C, C1, 2C and CPII) suggest different pathophysiologies in patients with hip osteoarthritis

BACKGROUND: Cartilage destruction in osteoarthritis (OA) involves excessive degradation and increased synthesis of cartilage matrix macromolecules including type II collagen and proteoglycans. Cartilage biomarkers exist for the measurement of cartilage matrix turnover and may reveal differences in patients with OA. OBJECTIVE: To determine whether there are detectable differences in and relationships between biomarkers of type II collagen (CII) degradation (C2C, C1, 2C) and synthesis (CP II) in patients with only hip OA (OHOA) and those suffering from multiple sites OA (MSOA). PATIENTS AND METHODS: Fifty-six patients classified as MSOA or OHOA. Minimum hip joint space width (Min JSW) measured by computer from standard radiographs. Serum measurement of CII synthesis C-propeptide (CPII) and cleavage of type II (C2C) and types I and II (C1, 2C) collagens. Aggrecan metabolism was assessed by serum CS 846 assay. Step to step logistic regression to determine the effect of the quantitative data on the assignment to each subgroup.RESULTS:Twenty-four subjects were classified with MSOA. Among the 32 OHAO patients, 15 had bilateral hip OA and 17 had unilateral hip OA. The latter were classified with "Isolated hip OA" (IHOA). CPII levels were significantly lower in patients with MSOA than in those with OHOA (99.9+/-50.3ng/mL versus 141.9+/-81.2ng/mL, p=0.04. OR= 0.18 for CPII >120 ng/mL, p<0.005). C2C levels were also lower in MSOA (9.7+/-2.3ng/mL) versus OHOA (11.4+/-3.2ng/mL, p=0.03. OR= 0.26 for C2C >10 ng/mL, p=0.02). There was an inverse correlation between min JSW and C2C only in patients with IHOA (r=0.50, p= 0.02). CONCLUSION: Hip OA, in patients with MSOA, might be related to alteration in CII metabolism which may result in a deficient type II collagen repair process. The significant relationship between C2C and JSW in IHOA suggests that this marker is of value in assessing cartilage degradation patients with involvement of a single joint.