The different influence of high levels of physical activity on the incidence of knee OA in overweight and obese men and women-a gender specific analysis.

OBJECTIVE: To investigate the influence of physical activity on incidence of knee osteoarthritis (OA) in overweight and obese men and women. DESIGN: Data were extracted from the Osteoarthritis Initiative cohort on 1,667 participants without symptomatic knee OA at baseline. We used logistic regression and marginal effect models to estimate the effect of body mass index (BMI) and reported physical activity score, together with the interaction between them, on the development of radiographic knee OA, symptomatic knee OA and joint space narrowing (JSN) after 96-months. RESULTS: Men in the most active quartile had almost double the likelihood of knee OA, independent of OA definition [e.g., odds ratio (OR) 2.4 (95%CI: 1.2-4.5) for radiographic knee OA]. Interaction analyses showed statistically significant interactions between physical activity and BMI on developing knee OA (i) radiographic OA interaction(P = 0.039), (ii) symptomatic OA interaction(P = 0.022), (iii) JSN interactionP = 0.012). The margin plots in men also demonstrated that the effect of physical activity on different measures of knee OA were modified by high levels of BMI. These effects were not mirrored in women where at all BMI levels, the level of reported physical activity did not influence likelihood of knee OA independent of OA definition. CONCLUSIONS: In overweight and obese men, there appears to be a threshold above which increasing levels of physical activity are associated with higher risk of knee OA. This is absent in women.

Mapping existing hip and knee replacement registries in Europe.

The general shortage of evidence regarding benefits and harms of medical devices has been highlighted following the serious safety concerns with metal-on-metal hip replacements and silicone breast implants and was again pointed out in a recent survey of European Health Technology Assessment institutions. In this context the new European medical device regulation will enforce post-marketing surveillance of existing and new implants. The usefulness of registry data as a source of information for medical device real-world clinical performance and safety has been demonstrated. However, these data might be under-used by researchers and policy makers. One reason for this is the insufficient awareness of their existence. The aim of this review is to provide information to relevant stakeholders on the extent and breadth of the data currently collected in European joint replacement registries. We identified 24 registries, most of them of national coverage. Total numbers of primary total hip and knee replacements included were over 3.1 and 2.5 million records, respectively. The current focus of these registries is on whole-lifespan implant surveillance via revision rate monitoring, quality assessment of surgical and perioperative care, and hospital performance assessment. More recently, national and international comparison and benchmarking have increasingly become part of their endeavors.

Vertebral Scheuermann's disease in Europe: prevalence, geographic variation and radiological correlates in men and women aged 50 and over.

UNLABELLED: In 27 centres across Europe, the prevalence of deforming spinal Scheuermann's disease in age-stratified population-based samples of over 10,000 men and women aged 50+ averaged 8% in each sex, but was highly variable between centres. Low DXA BMD was un-associated with Scheuermann's, helping the differential diagnosis from osteoporosis. INTRODUCTION: This study aims to assess the prevalence of Scheuermann's disease of the spine across Europe in men and women over 50 years of age, to quantitate its association with bone mineral density (BMD) and to assess its role as a confounder for the radiographic diagnosis of osteoporotic fracture. METHODS: In 27 centres participating in the population-based European Vertebral Osteoporosis Study (EVOS), standardised lateral radiographs of the lumbar and of the thoracic spine from T4 to L4 were assessed in all those of adequate quality. The presence of Scheuermann's disease, a confounder for prevalent fracture in later life, was defined by the presence of at least one Schmorl's node or irregular endplate together with kyphosis (sagittal Cobb angle >40° between T4 and T12) or a wedged-shaped vertebral body. Alternatively, the (rare) Edgren-Vaino sign was taken as diagnostic. The 6-point-per-vertebral-body (13 vertebrae) method was used to assess osteoporotic vertebral shape and fracture caseness. DXA BMD of the L2-L4 and femoral neck regions was measured in subsets. We also assessed the presence of Scheuermann's by alternative published algorithms when these used the radiographic signs we assessed. RESULTS: Vertebral radiographic images from 4486 men and 5655 women passed all quality checks. Prevalence of Scheuermann's varied considerably between centres, and based on random effect modelling, the overall European prevalence using our method was 8% with no significant difference between sexes. The highest prevalences were seen in Germany, Sweden, the UK and France and low prevalences were seen in Hungary, Poland and Slovakia. Centre-level prevalences in men and women were highly correlated. Scheuermann's was not associated with BMD of the spine or hip. CONCLUSIONS: Since most of the variation in population impact of Scheuermann's was unaccounted for by the radiological and anthropometric data, the search for new genetic and environmental determinants of this disease is encouraged.

Epidemiological evidence against a role for C-reactive protein causing leptin resistance.

OBJECTIVE: It has been suggested that elevated levels of C-reactive protein (CRP) might interfere with leptin signalling and contribute to leptin resistance. Our aim was to assess whether plasma levels of CRP influence leptin resistance in humans, and our hypothesis was that CRP levels would modify the cross-sectional relationships between leptin and measures of adiposity. DESIGN AND METHODS: W assessed four measures of adiposity: BMI, waist circumference, fat mass and body fat (%) in 2113 British Regional Heart Study (BRHS) men (mean (s.d.) age 69 (5) years), with replication in 760 (age 69 (6) years) European Male Ageing Study (EMAS) subjects. RESULTS: IN BRHS subjects, leptin correlated with CRP (SPEARMAN'S R=0.22, P0.0001). Leptin and crp correlated with all four measures of adiposity (R VALUE RANGE: 0.22-0.57, all P<0.0001). Age-adjusted mean levels for adiposity measures increased in relation to leptin levels, but CRP level did not consistently influence the ß-coefficients of the regression lines in a CRP-stratified analysis. In BRHS subjects, the BMI vs leptin relationship demonstrated a weak statistical interaction with CRP (P=0.04). We observed no similar interaction in EMAS subjects and no significant interactions with other measures of adiposity in BRHS or EMAS cohorts. CONCLUSION: We have shown that plasma CRP has little influence on the relationship between measures of adiposity and serum leptin levels in these middle-aged and elderly male European cohorts. This study provides epidemiological evidence against CRP having a significant role in causing leptin resistance.

Frailty Is Associated with Impaired Quality of Life and Falls in Middle-Aged and Older European Men.

OBJECTIVES: Adapt a measure of frailty for use in a cohort study of European men and explore relationships with age, health related quality of life and falls. DESIGN: Longitudinal cohort study. SETTING: 8 European centers. PARTICIPANTS: 3047 men aged 40-79 participating in the European Male Ageing Study (EMAS). MEASUREMENTS: Frailty was assessed using an adaptation of the Cardiovascular Health Study criteria. Health related quality of life was evaluated using the Rand Short Form-36 (SF-36) questionnaire which comprises both mental and physical component scores. Self reported falls in the preceding 12 months were recorded at 2-year follow-up. RESULTS: 78 men (2.6%) were classified as frail (≥3 criteria) and 821 (26.9%) as prefrail (1-2 criteria). The prevalence of frailty increased from 0.1% in men aged 40-49 up to 6.8% in men aged 70-79. Compared to robust men, both prefrail and frail men had lower health related quality of life. Frailty was more strongly associated with the physical than mental subscales of the SF-36. Frailty was associated with higher risk of falls OR (95% CI) 2.92 (1.52, 5.59). CONCLUSIONS: Frailty, assessed by the EMAS criteria, increased in prevalence with age and was related to poorer health related quality of life and higher risk of falls in middle-aged and older European men. These criteria may help to identify a vulnerable subset of older men.

Influence of age and sex steroids on bone density and geometry in middle-aged and elderly European men.

SUMMARY: The influence of age and sex steroids on bone density and geometry of the radius was examined in two European Caucasian populations. Age-related change in bone density and geometry was observed. In older men, bioavailable oestradiol may play a role in the maintenance of cortical and trabecular bone mineral density (BMD). INTRODUCTION: To examine the effect of age and sex steroids on bone density and geometry of the radius in two European Caucasian populations. METHODS: European Caucasian men aged 40-79 years were recruited from population registers in two centres: Manchester (UK) and Leuven (Belgium), for participation in the European Male Ageing Study. Total testosterone (T) and oestradiol (E(2)) were measured by mass spectrometry and the free and bioavailable fractions calculated. Peripheral quantitative computed tomography was used to scan the radius at distal (4%) and midshaft (50%) sites. RESULTS: Three hundred thirty-nine men from Manchester and 389 from Leuven, mean ages 60.2 and 60.0 years, respectively, participated. At the 50% radius site, there was a significant decrease with age in cortical BMD, bone mineral content (BMC), cortical thickness, and muscle area, whilst medullary area increased. At the 4% radius site, trabecular and total volumetric BMD declined with age. Increasing bioavailable E(2) (bioE(2)) was associated with increased cortical BMD (50% radius site) and trabecular BMD (4% radius site) in Leuven, but not Manchester, men. This effect was predominantly in those aged 60 years and over. In older Leuven men, bioavailable testosterone (Bio T) was linked with increased cortical BMC, muscle area and SSI (50% radius site) and total area (4% radius site). CONCLUSIONS: There is age-related change in bone density and geometry at the midshaft radius in middle-aged and elderly European men. In older men bioE(2) may maintain cortical and trabecular BMD. BioT may influence bone health through associations with muscle mass and bone area.

Chronic widespread pain is associated with slower cognitive processing speed in middle-aged and older European men.

Evidence from clinic-based studies suggests that the fibromyalgia syndrome (FMS) is associated with impairment in cognitive function though the mechanism is unclear. The aim of this analysis was to determine whether there is a similar association between chronic widespread pain (CWP), a cardinal feature of FMS, and impaired cognition in a community setting. Men (n=3369, 40-79 years) were recruited from population registers in eight centres for participation in the European Male Ageing Study (EMAS). The subjects completed a pain questionnaire and pain manikin, with the presence of CWP defined using the American College of Rheumatology criteria. The cognitive functions measured were visuospatial-constructional ability and visual memory (Rey-Osterrieth Complex Figure [ROCF]); visual recognition (Camden Topographical Recognition Memory test [CTRM]); and psychomotor processing speed (Digit-Symbol Substitution test [DSST]). We restricted our analysis to those subjects reporting pain that satisfied the criteria for CWP and those who were pain free. Of these 1539 men [mean (SD) age 60 (11) years], 266 had CWP. All cognitive test scores declined cross-sectionally with age (P<0.05). In age-adjusted linear regressions men with CWP had a lower DSST score (ß=-2.4, P<0.001) compared to pain-free subjects. After adjustment for lifestyle and health factors the association between pain status and the DSST score was attenuated but remained significant (ß=-1.02, P=0.04). There was no association between CWP and the ROCF-copy, ROCF-recall or CTRM scores. CWP is associated with slower psychomotor processing speed among community-dwelling European men. Prospective studies are required to confirm this observation and explore possible mechanisms for the association.

Gonadal sex steroid status and bone health in middle-aged and elderly European men.

SUMMARY: The influence of sex steroids on calcaneal quantitative ultrasound (QUS) parameters was assessed in a population sample of middle-aged and elderly European men. Higher free and total E(2) though not testosterone, were independently associated with higher QUS parameters. INTRODUCTION: The aim of this study was to investigate the association between QUS parameters and sex steroids in middle-aged and elderly European men. METHODS: Three thousand one hundred forty-one men aged between 40 and 79 years were recruited from eight European centres for participation in a study of male ageing: the European Male Ageing Study. Subjects were invited by letter to attend for an interviewer-administered questionnaire, blood sample and QUS of the calcaneus (Hologic-SAHARA). Blood was assessed for sex steroids including oestradiol (E(2)), testosterone (T), free and bio-available E(2) and T and sex hormone binding globulin (SHBG). RESULTS: Serum total T was not associated with any of the QUS parameters. Free T and both free and total E(2) were positively related to all QUS readings, while SHBG concentrations were negatively associated. These relationships were observed in both older and younger (<60 years) men. In a multivariate model, after adjustment for age, centre, height, weight, physical activity levels and smoking, free E(2) and SHBG, though not free T, remained independently associated with the QUS parameters. After further adjustment for IGF-1, however, the association with SHBG became non-significant. CONCLUSION: Higher free and total E(2) are associated with bone health not only among the elderly but also middle-aged European men.

Non-steroidal anti-inflammatory drug use does not appear to be associated with increased cardiovascular mortality in patients with inflammatory polyarthritis: results from a primary care based inception cohort of patients.

OBJECTIVES: There is controversy about the effects of non-steroidal anti-inflammatory drugs (NSAIDs) on cardiovascular disease (CVD) mortality. The aim of this study was to explore associations between NSAID use and mortality in patients with inflammatory polyarthritis (IP). SUBJECTS AND METHODS: A total of 923 patients with new onset (IP), recruited to the UK Norfolk Arthritis Register (NOAR) between 1990-1994, were followed up to the end of 2004. Current medication was recorded annually for the first 6 years and then every 2-3 years. Rheumatoid factor (RF) and C-reactive protein (CRP) were measured. Logistic regression was used to calculate all cause and CVD mortality odds ratios (OR) for NSAID use at baseline and during follow-up, adjusting for gender and time-varying covariates: RF, CRP, joint counts, smoking, steroid use, DMARD use and other medication use. RESULTS: By 2004 there were 203 deaths, 85 due to CVD. At baseline, NSAIDs were used by 66% of patients. In final multivariate models, baseline NSAID use was inversely associated with all cause mortality (adjusted OR 0.62, 95% CI 0.45 to 0.84) and CVD mortality (adjusted OR 0.54, 95% CI 0.34 to 0.86). Interval NSAID use had weaker mortality associations: all cause mortality (adjusted OR 0.72, 95% CI 0.52 to 1.00), CVD mortality (adjusted hazard ratio (HR) 0.66, 95% CI 0.40 to 1.08). CONCLUSION: No excess CVD or all cause mortality was observed in NSAID users in this cohort of patients with IP. This is at variance with the literature relating to NSAID use in the general population. It is unclear whether this represents unmeasured confounders influencing a doctor's decision to avoid NSAIDs in the treatment of IP.

Can clinical factors at presentation be used to predict outcome of treatment with methotrexate in patients with early inflammatory polyarthritis?

PURPOSE: Methotrexate (MTX) is the first choice conventional disease-modifying antirheumatic drug (DMARD) for rheumatoid arthritis. It is not universally effective, however; although to date it is not possible to predict with any accuracy which patients will respond to treatment. The aim of this analysis was to examine whether clinical and genetic variables could be used to predict response to MTX. METHODS: Patients recruited to the Norfolk Arthritis Register (NOAR), a primary care based inception cohort of patients with inflammatory polyarthritis, were eligible for this analysis if they were commenced on MTX as their first DMARD within 3 months of their baseline visit and had at least 2 years of follow-up data. Outcome on MTX was defined as: (1) stopped for adverse events; (2) stopped for inefficacy or second DMARD added; (3) stopped for other reasons; or (4) remained on MTX monotherapy. Multiple logistic regression was used to establish which variables (including demographics, disease activity and Health Assessment Questionnaire score) predicted stopping monotherapy for inefficacy or adverse event (with those remaining on treatment taken as the referent category). The area under the Receiver Operating Characteristic curves (AUC ROC), were used to determine how accurate the model was at predicting outcome. RESULTS: 309 patients were included in this analysis. At 1 year (2 years), 34 (46) patients had stopped for adverse events and 25 (49) had either stopped monotherapy for inefficacy or had a second DMARD added. 231 (188) patients remained on MTX monotherapy. The strongest predictor of inefficacy at both time points was shared epitope positivity: odds ratios (OR) 5.8 (95% confidence intervals (CI) 1.3 to 25.6) at 1 year, OR 3.0 (95% CI 1.3 to 7.3) at 2 years. High Health Assessment Questionnaire score (OR 1.84 95% CI 1.12 to 3.01) and female gender (OR 2.2, 95% CI 0.92 to 5.28) were associated with adverse events on MTX at 1 year. However, even the most optimal combinations of the factors analysed were only weakly predictive of treatment outcome: AUC ROC for adverse events 0.68 (95% CI 0.58 to 0.78) and for inefficacy AUC ROC 0.71 (95% CI 0.6 to 0.81). CONCLUSIONS: Within this cohort, routine clinical and laboratory factors were poor at predicting outcome of treatment with MTX. Given the major therapeutic advantage to be derived from accurate prediction of treatment outcome, further studies will need to investigate novel biological and other markers.

European biologicals registers: methodology, selected results and perspectives.

With the licensing of the first tumour necrosis factor (TNF)alpha inhibitors, independent academia-initiated but industry-sponsored drug registers were set up by the national rheumatology societies in several European countries in order to monitor the long-term safety and effectiveness of this new generation of drugs. Even though different in some respects of study design and monitoring, the registers share a number of common features: they include all licensed biological agents, they observe the patients for a defined period of time or indefinitely irrespective of the drug given and they use comparator cohorts or national registers in order to put the results into perspective. The registers have been collaborating closely since inception. Three of them (the British, Swedish and German registers) have agreed on a standardised reporting system of adverse events which ensures a high and uniform quality of data submitted to the companies, who subsequently report to the drug regulatory authorities, enabling regulatory requirements on safety surveillance to be fulfilled. In the present work, major results on drug safety with regard to infections, malignancies, cardiovascular events, pregnancy outcomes and deaths are summarised. With an increasing number of new drugs and multiple exposures of individual patients the assignment of events to specific treatments will become exceedingly difficult. This and other methodological challenges and the approaches to cope with them are discussed. A growing dialogue between drug regulatory authorities, academic medicine and companies in order to make best use of the potentials of academia-driven drug registers as new tools for pharmacovigilance with currently described rheumatology registers as prototypes is anticipated.

Investigating the determinants of international differences in the prevalence of chronic widespread pain: evidence from the European Male Ageing Study.

OBJECTIVES: To determine whether among middle-aged and elderly men there is evidence of international differences in the prevalence of chronic widespread pain (CWP) and whether any such differences could be explained by psychological, psychosocial factors or differences in physical health status. METHODS: The European Male Ageing Study (EMAS) sampled from population registers in cities (centres) of eight European countries. Each centre recruited an age-stratified sample of men aged 40-79 years. Information on pain was collected by questionnaire and subjects were classified according to whether they satisfied the American College of Rheumatology definition of CWP. Information was collected on social status, mental health, recent life events and co-morbidities. RESULTS: Across all centres 3963 subjects completed a study questionnaire, with participation rates ranging from 24% in Hungary to 72% in Estonia. There were significant differences in prevalence: between 5% and 7% in centres in Italy, England, Belgium and Sweden, 9-15% in centres in Spain, Poland and Hungary and 15% in Estonia. There were strong relationships between poor mental health, adverse recent life events, co-morbidities and CWP. Adjustment for these factors explained between half and all of the excess risk in the eastern European centres: the excess risk in Poland was explained (odds ratio (OR) 1.1, 95% CI 0.9 to 1.2) but there remained excess risk in Hungary (OR 1.6, 95% CI 1.4 to 1.8) and Estonia (OR 2.6, 95% CI 2.2 to 2.9). CONCLUSIONS: This study is the first directly to compare the occurrence of CWP internationally. There is an excess prevalence in countries of eastern Europe and this excess is associated with adverse psychosocial factors as well as poorer psychological and physical health.

Evaluation of work-related psychosocial factors and regional musculoskeletal pain: results from a EULAR Task Force.

OBJECTIVES: To establish whether review articles provide consistent conclusions on associations between workplace psychosocial factors and musculoskeletal pain and, if differences exist, to explore whether this is related to the methods used. METHODS: Reviews, reported up to February 2007, that included consideration of workplace psychosocial factors and upper limb, back or knee pain were identified through searches of multiple databases. The specific work-related psychosocial factors considered were job demands, support, job autonomy and job satisfaction. The conclusions of each review on one or more of the psychosocial/musculoskeletal pain associations were extracted. RESULTS: 15 review articles were identified that considered one or more of the regional pain syndromes included in the study. For back pain, the most consistent conclusions (four reviews positive out of six) were with high job demands and low job satisfaction. The studies of upper limb pain were exclusively related to shoulder and/or neck pain, and the most consistent positive conclusions were with high and low job demands (four reviews positive out of six and two reviews positive out of three, respectively). For knee pain, only a single review was identified. For individual reviews of back and upper limb pain, there were marked differences in the number of associations concluded to be positive between reviews. CONCLUSIONS: The reasons for reviews coming to different conclusions included that they were often evaluating different bodies of evidence (according to their search criteria, the year when the review was conducted, the role that quality assessment played in whether studies contributed to evidence, and the combination of risk factors addressed in individual studies), but more important was whether the review specified explicit criteria for making conclusions on strength of evidence. These conclusions emphasise the importance of developing standardised methods for conducting such evaluations of existing evidence and the importance of new longitudinal studies for clarifying the temporal relationship between psychosocial factors and musculoskeletal pain in the workplace.

Musculoskeletal pain is associated with a long-term increased risk of cancer and cardiovascular-related mortality.

OBJECTIVES: To test the hypothesis that individuals with regional and widespread pain disorders have an increased risk of mortality. METHODS: We conducted a prospective cohort study of 4515 adults. Subjects were an age- and sex-stratified sample who had participated in a population study of pain occurrence during 1996. Based on those reports subjects were classified as having no pain, regional pain or widespread pain. All subjects were identified on the National Health Service Central Register and followed up until April 2005, a total of 8.2 yrs, at which time information was obtained on vital status, and if applicable, date and cause of death. The relationship between pain status and subsequent death is expressed as mortality rate ratios with 95% CIs, adjusted for age, gender, ethnicity and practice. RESULTS: A total of 35.2% reported regional pain and 16.9% satisfied criteria for widespread pain. In comparison with those without pain, there was a 20% and 30% increased risk of dying over the follow-up period among subjects with regional and widespread pain, respectively. The specific causes of death in excess were cancer and cardiovascular disease. In addition, the mortality risk from both cancer and cardiovascular deaths was found to increase as the number of pain sites that subjects reported increased. CONCLUSIONS: This study supports a previous observation that persons with regional and widespread pain are at an increased risk of cancer death. Possible mechanisms should be explored.

Ethical and legal constraints on data sharing between countries in multinational epidemiological studies in Europe report from a joint workshop of the European League Against Rheumatism standing committee on epidemiology with the "AutoCure" project.

BACKGROUND: We report on a workshop on ethical and legal constraints on data sharing between countries in multinational epidemiologic research in Europe that was held in January 2007 in Potsdam, Germany. The participants were experienced epidemiologic and clinical researchers from eight European countries. The aim of the workshop was to share current knowledge on the above-mentioned topics, to identify areas for joint action and to enhance the likelihood of success for the new funding programmes. METHODS: Workshop sessions and review of findings. RESULTS: Key elements and recommendations have been drawn up. CONCLUSIONS: Epidemiologic and clinical studies are increasingly planned and conducted on a European level, and funds are available for this kind of studies. However, data sharing in multi-centre clinical and epidemiological studies is hampered by the different legal and ethical constraints individual national researchers face.

Investigating the role of the HLA-Cw*06 and HLA-DRB1 genes in susceptibility to psoriatic arthritis: comparison with psoriasis and undifferentiated inflammatory arthritis.

OBJECTIVE: Psoriasis of early onset (type I; age of onset 40 years). HLA-DRB1*07, in linkage disequilibrium with HLA-Cw*06, was also associated with patients with PsA having type I psoriasis (OR 2.7, 95% CI 2.1, 3.7, p<0.00001). HLA-DRB1*04 alleles and the SE were associated with undifferentiated inflammatory arthritis but not with PsA. CONCLUSIONS: The SE is not a PsA susceptibility locus. HLA-Cw*06 and HLA-DRB1*07 are associated with patients with PsA having type I psoriasis, suggesting that the primary association is with age of onset of psoriasis. Patients with PsA having type I psoriasis, therefore, have a genetic background different to those with type II psoriasis, and adjustment for this is necessary in future studies that investigate the genetic susceptibility of PsA.

Environmental risk factors for the development of psoriatic arthritis: results from a case-control study.

OBJECTIVE: To identify potential risk factors for the onset of inflammatory arthritis (IA) in a large cohort of patients with psoriatic arthritis (PsA) of recent onset. METHODS: We recruited cases with psoriasis and an onset of IA within the past 5 years. Controls were patients who had psoriasis but no arthritis. We assessed potential factors associated with the development of IA using a detailed postal questionnaire. An unmatched analysis adjusted for age and gender was performed. Exposure was censored in the controls at a "dummy-date" assigned randomly in proportion to the percentage of cases developing IA in any given year. RESULTS: We studied 98 cases and 163 controls. Exposures showing a positive association before the onset of IA in patients with psoriasis were: rubella vaccination (OR (95% CI) = 12.4 (1.2 to 122)), injury sufficient to require a medical consultation (2.53 (1.1 to 6.0)), recurrent oral ulcers (4.2 (2.0 to 9.0)) and moving house (2.3 (1.2 to 4.4)). Cases were also more likely to have experienced a fractured bone requiring hospital admission (50% vs 9%, p = 0.040). CONCLUSIONS: We found a number of environmental exposures associated with the onset of IA in subjects with psoriasis. The strongest associations were with trauma thereby adding to the hypothesis of a "deep Koebner phenomenon" in PsA. Our data also suggest that exposure of the immune system to certain infection-related triggers may also be of relevance. Further studies are needed to verify these observations and to examine potential immunological mechanisms that underlie them.

Reduction in the incidence of myocardial infarction in patients with rheumatoid arthritis who respond to anti-tumor necrosis factor alpha therapy: results from the British Society for Rheumatology Biologics Register.

OBJECTIVE: Rheumatoid arthritis (RA) is associated with an increased risk of coronary artery disease, possibly acting via shared mechanisms of inflammation. This study was undertaken to test the hypothesis that the powerful antiinflammatory effect of anti-tumor necrosis alpha (anti-TNFalpha) therapy might lead to a reduction in the incidence of myocardial infarction (MI) in patients with RA. METHODS: Using data from the British Society for Rheumatology Biologics Register, a national prospective observational study, we compared MI rates in 8,670 patients with RA treated with anti-TNFalpha and 2,170 patients with active RA treated with traditional disease-modifying antirheumatic drugs (DMARDs). RESULTS: Through July 2006, 63 MIs occurred in the anti-TNFalpha cohort during 13,233 person-years of followup and 17 MIs occurred in the DMARD cohort during 2,893 person-years of followup, equivalent to a rate of 4.8 events per 1,000 person-years and 5.9 events per 1,000 person-years, respectively. After adjustment for baseline risk factors, there was no reduction in the rate of MI in the anti-TNFalpha cohort compared with the DMARD cohort (incidence rate ratio 1.44 [95% confidence interval 0.56-3.67]). In an analysis of anti-TNFalpha-treated patients who responded to the treatment within 6 months versus those who did not, MI rates were found to be 3.5 events per 1,000 person-years in responders and 9.4 events per 1,000 person-years in nonresponders. The adjusted incidence rate ratio (95% confidence interval) for responders compared with nonresponders was 0.36 (0.19-0.69). CONCLUSION: These results indicate that RA patients treated with anti-TNFalpha do not have a lower incidence of MI compared with RA patients treated with traditional DMARDs. However, the risk of MI is markedly reduced in those who respond to anti-TNFalpha therapy by 6 months compared with nonresponders. This finding supports the notion that inflammation plays a pivotal role in MI.

Serious infection following anti-tumor necrosis factor alpha therapy in patients with rheumatoid arthritis: lessons from interpreting data from observational studies.

OBJECTIVE: In a recent observational study, we found that the risk of serious infection following anti-tumor necrosis factor alpha (anti-TNFalpha) therapy in patients with rheumatoid arthritis (RA) was not importantly increased compared with the background risk in routinely treated RA patients with similar disease severity. Observational data sets are, however, subject to a number of important biases related to selection factors for the timing of starting and stopping therapy. Infection risk is also likely to vary with duration of therapy. This study was undertaken to examine the influences of these biases and of the method of analysis on the risk of infection. METHODS: We compared the risk of serious infection in 8,659 patients treated with anti-TNFalpha with that in 2,170 patients treated with traditional disease-modifying antirheumatic drugs (DMARDs) recruited to the British Society for Rheumatology Biologics Register. We applied a number of statistical models in which we varied the length of the followup period by using different definitions of the date of discontinuation of treatment and different lag periods of risk following drug cessation. RESULTS: When the at-risk period was defined as "receiving treatment", the adjusted incidence rate ratio comparing patients receiving anti-TNFalpha therapy with patients receiving DMARD therapy was 1.22 (95% confidence interval [95% CI] 0.88-1.69). Limiting followup to the first 90 days, however, revealed an adjusted incidence rate ratio of 4.6 (95% CI 1.8-11.9). Rates of infection were increased in the 90 days immediately following drug discontinuation and beyond, explained by selection factors for drug discontinuation. CONCLUSION: These findings show that overall, the way in which UK rheumatologists select patients for starting and discontinuing anti-TNFalpha therapy explains our previous finding of no increase in risk. However, there may be important increases in true risk, notably early in the course of treatment, that would become more evident depending on the definition of at-risk period.