Identifying specific profiles in patients with different degrees of painful knee osteoarthritis based on serological biochemical and mechanistic pain biomarkers: a diagnostic approach based on cluster analysis.

Biochemical and pain biomarkers can be applied to patients with painful osteoarthritis profiles and may provide more details compared with conventional clinical tools. The aim of this study was to identify an optimal combination of biochemical and pain biomarkers for classification of patients with different degrees of knee pain and joint damage. Such profiling may provide new diagnostic and therapeutic options. A total of 216 patients with different degrees of knee pain (maximal pain during the last 24 hours rated on a visual analog scale [VAS]) (VAS 0-100) and 64 controls (VAS 0-9) were recruited. Patients were separated into 3 groups: VAS 10 to 39 (N = 81), VAS 40 to 69 (N = 70), and VAS 70 to 100 (N = 65). Pressure pain thresholds, temporal summation to pressure stimuli, and conditioning pain modulation were measured from the peripatellar and extrasegmental sites. Biochemical markers indicative for autoinflammation and immunity (VICM, CRP, and CRPM), synovial inflammation (CIIIM), cartilage loss (CIIM), and bone degradation (CIM) were analyzed. WOMAC, Lequesne, and pain catastrophizing scores were collected. Principal component analysis was applied to select the optimal variable subset, and cluster analysis was applied to this subset to create distinctly different knee pain profiles. Four distinct knee pain profiles were identified: profile A (N = 27), profile B (N = 59), profile C (N = 85), and profile D (N = 41). Each knee pain profile had a unique combination of biochemical markers, pain biomarkers, physical impairments, and psychological factors that may provide the basis for mechanism-based diagnosis, individualized treatment, and selection of patients for clinical trials evaluating analgesic compounds. These results introduce a new profiling for knee OA and should be regarded as preliminary.

Impact of source data verification on data quality in clinical trials: an empirical post hoc analysis of three phase 3 randomized clinical trials.

AIM: The aim of this project was to perform an empirical evaluation of the impact of on site source data verification (SDV) on the data quality in a clinical trial database to guide an informed decision on selection of the monitoring approach. METHODS: We used data from three randomized phase III trials monitored with a combination of complete SDV or partial SDV. After database lock, individual subject data were extracted from the clinical database and subjected to post hoc complete SDV. Error rates were calculated with focus on the degree of on study monitoring and relevance and analyzed for potential impact on end points. RESULTS: Data from a total of 2566 subjects including more than 3 million data fields were 100% source data verified post hoc. An overall error rate of 0.45% was found. No sites had 0% errors. 100% SDV yielded an error rate of 0.27% as compared with partial SDV having an error rate of 0.53% (P < 0.0001). Comparing partly and fully monitored subjects, minor differences were identified between variables of major importance to efficacy or safety. CONCLUSIONS: The findings challenge the notion that a 0% error rate is obtainable with on site monitoring. Data indicate consistently low error rates across the three trials analyzed. The use of complete vs. partial SDV offers a marginal absolute error rate reduction of 0.26%, i.e. a need to perform complete SDV of about 370 data points to avoid one unspecified error and does not support complete SDV as a means of providing meaningful improvements in data accuracy.

Type X collagen levels are elevated in serum from human osteoarthritis patients and associated with biomarkers of cartilage degradation and inflammation.

BACKGROUND: Osteoarthritis (OA) is the most common degenerative joint disease, of which the pathogenesis is inadequately understood. Hypertrophy-like changes have been observed as part of the progression of OA. The aim of the study was to develop and characterize a novel biomarker of chondrocytes hypertrophy and investigate how this marker was associated with cartilage degradation and inflammation in patients with various degrees of OA. METHODS: A competitive ELISA, C-Col10, applying a well-characterized monoclonal antibody was developed as a biomarker of chondrocyte hypertrophy through measurement of type X collagen (ColX). The levels of C-Col10, C2M (matrix metalloproteinase-derived fragments of type II collagen) and hsCRP (high sensitive C-reactive protein) were quantified by ELISAs in serum of 271 OA patients stratified by Kellgren-Lawrence (KL) score 0-4. Associations between serum levels of the three biomarkers (log transformed) were analyzed by Pearson's correlation and differences in C-Col10 levels between patients with high and low levels of inflammation measured by hsCRP were analyzed by ANOVA. RESULTS: We developed a C-Col10 assay measuring the C-terminus of ColX. We found significantly higher levels of ColX in patients with KL score 2 compared to patients with no radiographic evidence of OA (KL0) (p = 0.04). Levels of ColX were significantly elevated in OA patients with above normal hsCRP levels (p < 0.0001), as well as significantly correlated with levels of C2M (r = 0.55, p < 0.0001), which suggested that chondrocyte hypertrophy was associated with inflammation and cartilage degradation. There was no correlation between C2M and hsCRP. Age and BMI adjustment didn't change the results. Immuno-staining revealed that ColX was predominately located around the hypertrophic chondrocytes and the clustered chondrocytes indicating that C-Col10 measures may be linked to cartilage hypertrophic changes. CONCLUSIONS: We developed a novel assay, C-Col10, for measurement of chondrocyte hypertrophy and found its levels significantly elevated in OA patients with KL score of 2, and also in OA patients with above normal hsCRP levels. Concentration of C-Col10 strongly correlated with levels of C2M, a marker of cartilage destruction. The data suggest that chondrocyte hypertrophy and subsequent collagen X fragmentation seem to be increased in a subset of patients with inflammatory OA.

Effects of high doses of cholecalciferol in normal subjects: a randomized double-blinded, placebo-controlled trial.

BACKGROUND: Vitamin D repletion with high doses of vitamin D is often recommended to patients and healthy subjects. The safety, especially concerning changes in urinary calcium excretion is of great importance. METHODS: In a double-blinded, placebo-controlled study in 40 healthy volunteers, we examined the changes in mineral metabolism during supplementation with 3000 IU of oral cholecalciferol daily during 4 months. RESULTS: Both 25(OH)vitamin D and 1,25(OH)2vitamin D increased significantly in the active treated group as compared to the placebo group (186% versus 14% (P<0.001) and 28% versus -8% (P<0.001)). No change was observed in urinary calcium excretion in the active group compared to the placebo group (P = 0.891). Fibroblast growth factor 23 increased significantly by 10% (P<0.018) in the active group. However, there was no difference in changes in FGF23 between treatment groups (P = 0.457). CONCLUSION: High dose cholecalciferol significantly increases 25(OH)vitamin D and 1,25(OH)2vitamin D levels compared to placebo. No changes in urinary calcium excretion or other measured components of the mineral metabolism were found between groups. TRIAL REGISTRATION: ClinicalTrials.gov NCT00952562.

Effect of cutaneous blood flow on absorption of insulin: a methodological study in healthy male volunteers.

Absorption of drugs from subcutaneous tissue depends on several factors, including tissue perfusion at the administration site. Tissue perfusion can be manipulated by e.g. application of local heat. This may subsequently alter the rate or amount of absorption of drugs from a subcutaneous depot. The aim of the present study was to investigate if increased tissue perfusion after controlled local heating can change the absorption of subcutaneously administered short-acting insulin (Actrapid®, 100IU/ml). Thirteen healthy Caucasian males participated in two randomized experimental sessions; one session with locally applied controlled heat at the injection site, and a control session without local heat application. Tissue perfusion (blood flow) was monitored with Laser Doppler Imaging, and blood samples were taken to assess the levels of glucose and insulin. Local heat application at the site of insulin injection significantly enhanced tissue perfusion by approximately 145%. However, no correlation was found between insulin absorption and tissue perfusion. Based on our findings, it was concluded that tissue perfusion is not the rate-limiting factor in the absorption of high-concentration short-acting insulin from a subcutaneous depot. It is suggested that dissociation of insulin hexamers into dimers and monomers is a major rate limiting factor to the absorption.

Optimizing the early phase development of new analgesics by human pain biomarkers.

Human pain biomarkers are based on standardized acute activation of pain pathways/mechanisms and quantitative assessment of the evoked responses. This approach can be applied to healthy volunteers, to pain patients, and before and after pharmacological interventions to help understanding and profile the mode of action (proof-of-concept) of new and existing analgesic compounds. Standardized stimuli of different modalities can be applied to different tissues (multimodal and multi-tissue) for profiling analgesic compounds with respect to modulation of pain transduction, transmission, specific mechanisms and processing. This approach substantiates which specific compounds may work in particular clinical pain conditions. Human pain biomarkers can be translational and may bridge animal findings in clinical pain conditions, which in turn can provide new possibilities for designing more successful clinical trials. Biomarker based proof-of-concept drug studies in either volunteers or selected patient populations provide inexpensive, fast and reliable mechanism-based information about dose-efficacy relationships. This is important information in the early drug development phase and for designing large expensive clinical trials.

Differences in zinc status between patients with osteoarthritis and osteoporosis.

Zinc has been suggested to play an important role in the development of osteoporosis, whereas the influence of zinc on osteoarthritis has attracted much less attention. The aim of the study was to investigate and compare the zinc status and bone turnover, density, and biomechanical properties of osteoarthritic and osteoporotic patients. The study comprised 40 women who underwent hip replacement due to osteoarthritis or osteoporosis. Serum and urine zinc content, and bone resorption markers and serum bone formation markers were determined. The unaffected hip and the exarticulated affected femoral head underwent DEXA scanning. Bone biopsies were obtained from the femoral heads and the biomechanical properties were determined. The biopsies were ashed and the bone zinc content was ascertained. Osteoarthritic patients had significantly higher serum zinc concentrations and lower urine zinc concentrations than osteoporotic patients, whereas the bone zinc content did not differ. The zinc status was not found to be a predictor for the bone strength. In conclusion, the finding that the zinc status of osteoporotic patients is significantly different from that of osteoartritic patients is new and supports the view that osteoporosis and osteoarthritis rarely occur in the same individual.

Fracture risk is increased in patients with GH deficiency or untreated prolactinomas--a case-control study.

OBJECTIVE: The pituitary secretes many hormones of significance to bone turnover and thus skeletal integrity. The aim of this study was to examine fracture risk in patients with pituitary disorders with special reference to GH deficiency and hyperprolactinaemia. DESIGN: Case-control study. MEASUREMENTS: Fracture occurrence. PATIENTS: A self-administered questionnaire was issued to 537 consecutive patients with pituitary disorders excluding Cushing's disease. A total of 426 (79%) returned the questionnaire and 422 of these could be analysed. Each respondent was compared to three age- and gender-matched control respondents to the same questionnaire drawn randomly from the background population. RESULTS: The patients had a mean age of 51.4 +/- 14.8 years. One hundred and eight patients had acromegaly, 86 had prolactinomas, 136 had non-functioning pituitary adenomas (NFPA), 23 had craniopharyngiomas, and 73 had other types of pituitary disorders. For the total group the fracture risk was not elevated either before or after confirmed diagnosis compared to controls. However, among the patients with prolactinomas, the fracture risk was significantly increased before (relative risk, RR = 1.6, 95% CI: 1.1--2.3) but not after diagnosis. In patients with NFPA, fracture risk was borderline significantly elevated following diagnosis (RR = 1.6, 95% CI: 1.0--2.6). Patients with subnormal stimulated peak GH values suggestive of GH deficiency had a significantly higher risk of fractures after diagnosis than patients who had normal stimulated peak GH values (odds ratio, OR = 4.90, 95% CI: 1.10--21.88). CONCLUSIONS: Untreated prolactinomas were associated with a significant increase in fracture risk. Growth hormone deficiency was also associated with a higher fracture risk.

Bone mineral content and bone metabolism during physiological GH treatment in GH-deficient adults--an 18-month randomised, placebo-controlled, double blinded trial.

OBJECTIVE: To evaluate the effect of physiological adult growth hormone (GH) replacement on bones. DESIGN: Thirty-six prospective severely growth hormone-deficient (GHD) adults (22 females and 14 males) were randomised to either 18 months of GH (0.03 mU/kg/day) or placebo treatment. METHODS: Bone mineral density and content (BMD, BMC) and body composition were evaluated by dual energy X-ray absorptiometry at baseline and after 6, 12 and 18 months. Serum concentrations of insulin-like growth factor-I (IGF-I), IGF binding protein 3, osteocalcin, carboxyterminal propeptide of type I collagen, carboxyterminal crosslink telopeptide of type I collagen, amino-terminal propeptide of type III procollagen and urine pyridinolin and deoxypyridinolin were determined. RESULTS: IGF-I levels increased from 63.2 microg/l (+/-10.1) to 193.6 (+/- 25.8) microg/l (mean (+/-s.e.)) (P<0.001 compared with placebo). Markers of bone turnover increased significantly from 142% to 227% of baseline values (all P<0.001 compared with placebo). Body composition changes were an increase of lean body mass and a decrease of fat mass resulting in a reduction of percentage body fat of +/- 1.8 (+/- 3.8) in the GH-treated group vs an increase of 1.0 (+/-2.9)) in the placebo-treated group (P=0.002). CONCLUSIONS: No significant difference in BMD or BMC between the GH and placebo groups was found after 18 months. At several sites the variances of changes from baseline were significantly greater in the GH than in the placebo group, indicating an impact of the treatment. From baseline to 6 months an insignificant reduction of total BMD was seen while an increase of BMD was found from 6 to 18 months in the GH group compared with the placebo group. This placebo-controlled trial confirmed the longer term open studies on the effect on bones in patients with GHD, with an initial overrepresentation of bone resorption followed by an increase in BMD which at 18 months had reached baseline level.

Smoking as a risk factor for Graves' disease, toxic nodular goiter, and autoimmune hypothyroidism.

To study the association between smoking and thyroid disease (Graves' disease [E05.0], nodular toxic goiter [E05.2], and autoimmune hypothyroidism [E03.9]) in a low-iodine intake area a case-control study was undertaken. A self-administered questionnaire was issued to 864 consecutive patients with hyperthyroidism and 628 patients with autoimmune hypothyroidism treated at five university or regional endocrinologic clinics in Denmark between January 1, 1990 and December 31, 1998. Each respondent was compared to an age- (+/- 5 years) and gender-matched normal control person randomly drawn from the background population. A total of 621 patients with hyperthyroidism (72%) and 411 patients with autoimmune hypothyroidism (66%) responded. Of these, 617 (542 females) and 408 (364 females) could be analyzed, respectively. There was an increased risk of both Graves' disease (odds ratio [OR] = 2.5, 95% confidence interval [CI]: 1.8-3.5), toxic nodular goiter (OR = 1.7, 95% CI: 1.1-2.5), and autoimmune hypothyroidism (OR = 1.5, 95% CI: 1.1-2.1) with ever smoking compared to never smoking in women, but not in men. With the high proportion of ever-smokers among women (56%), the attributable risk of smoking in women was 45% in Graves' disease, 28% in toxic nodular goiter, and 23% in autoimmune hypothyroidism. Ever use of oral contraceptives was associated with a slightly lower risk of Graves' disease in women, but not of toxic nodular goiter or autoimmune hypothyroidism. In conclusion, smoking is a powerful risk factor for thyroid disease, especially in populations with a high smoking frequency. Oral contraceptive use is associated with a slightly lower frequency of Graves' disease.

Increased risk of osteoporotic fractures in patients with Cushing's syndrome.

OBJECTIVE: To evaluate if fracture risk was increased in patients with Cushing's syndrome due to the increased endogenous cortisol production. DESIGN: Cohort. METHODS: A self-administered questionnaire was mailed to 125 patients with Cushing's syndrome diagnosed between 1985 and 1999 in Denmark. The response of each patient was compared with that of three age- and gender-matched control subjects randomly drawn among respondents to the same questionnaire from the background population. RESULTS: One hundred and four patients (83%) responded. The median age of the patients was 48 years (range 19-85 years). Sixty-eight had pituitary disease, 28 had adrenal disease, four had had both pituitary and adrenal surgery while four had not undergone surgery at the time of the study. The median time from diagnosis to surgery was 0.2 (range 0-3) years. Eighty-six percent were cured following surgery. There was an increased fracture risk within the last 2 years prior to diagnosis (incidence rate ratio 6.0, 95% confidence intervals (CI): 2.1-17.2). More than 2 years prior to diagnosis and following diagnosis there was no difference in fracture risk between patients and controls. The patients had more low-energy fractures than the controls (relative risk 5.4, 95% CI: 1.4-20.1). There was no difference in fracture risk between patients with adrenal or pituitary disease. CONCLUSIONS: Patients with Cushing's syndrome had an increased fracture risk in a narrow time interval before diagnosis, while no increase in fracture risk could be demonstrated after diagnosis and treatment.