POS1121 HAND OSTEOARTHRITIS IS ASSOCIATED WITH LIMITATIONS IN PAID AN UNPAID WORK PARTICIPATION AND RELATED SOCIETAL COSTS: THE HOSTAS COHORT

Background

Rheumatic musculoskeletal diseases (RMDs) can cause impairment in paid and unpaid work which can contribute to societal burden and costs. However, data on this topic concerning hand osteoarthritis (OA) is scarce, while this is crucial for assessing the societal impact of this disease.

Objectives

To investigate the association of hand OA with paid and unpaid work limitations, productivity loss and costs of productivity loss.

Methods

We used data of the Dutch Hand OSTeoArthritis in Secondary care (HOSTAS) cohort, a primary hand OA cohort from a general rheumatology outpatient clinic. The treating rheumatologist defined hand OA presence. We assessed patient and OA characteristics using validated questionnaires and tests. We investigated work impairment due to hand OA with the Health and Labour Questionnaire (HLQ) which assesses the last two weeks on hand-OA related limitations, hours of sick leave and unproductiveness during paid work, and limitations and hours of the necessity of being replaced by others for unpaid work tasks.

We estimated societal costs of paid work by multiplying unproductive and sick leave hours due to hand OA by the average Dutch hourly societal costs of paid work for persons of the same age category and sex. We estimated societal costs of unpaid work by multiplying the hours of unpaid work replaced by others by the Dutch gross average hourly salary of a household help (€12.50).

Results

HLQ data was available for 382 patients (mean age 61 years, 86% women, 26% having a university degree, 41% having any comorbidity). Of these persons, 181 (47%) had paid work, 16 (4%) had full work disability due to hand OA and 117 (30%) were retired. Thirteen employed persons (7%) reported sick leave due to hand OA in the last two weeks, for whom a median of 42 working hours (interquartile range (IQR) 24 to 54) was lost. Unproductive paid work hours were present for 28 (15%) patients, with a median of 4 hours in the last two weeks (IQR 2 to 6). Hinder at work in the last two weeks was reported by 120 out of 181 working patients (66%), for whom median hinder score (score range 6-24) was 7 (IQR 6 to 8). Work production loss in the last two weeks due to hand OA (the sum of sick leave hours and unproductive hours) was present for 36 patients (19%). Patients with paid work productivity loss (n = 35, 19%) did not differ statically significantly in patient and disease characteristics from those without productivity loss (n = 146, 19%).

Unpaid work replacement in the last two weeks was reported by 171 patients (45%), with a median of three hours replaced (IQR 2 to 7). Any unpaid work hinder was reported by 297 (78%). Median unpaid work hinder score (score range: 4-16) was 8 (IQR 7 to 10) . Patients with unpaid work replacement by others due to hand OA (n=171, 45%) were statically significantly more often female and had a higher BMI than with those without any replacement (n=210, 55%).

We estimated total societal costs of hand OA related to paid work production loss at €61 (95% confidence interval (CI) 27 to 96) per two weeks, and societal costs for unpaid work at €33 (CI 27 to 40). Total estimated work-related societal costs per patient with hand OA were €94 (CI 59 to 130), translating to €2452 (CI 1528 to 3377) per year.

Conclusion

Hand OA is associated with impairment in paid and unpaid work, which translates into substantial societal costs. This highlights the social and economic importance of adequate hand OA treatment. It also highlights the importance of investigating work impairment experienced by hand OA patients visiting the outpatient clinic, for potentially more tailored treatment.

Disclosure of Interests

None declared

AB0976 Determination and characterization of patient subgroups with different pain progression in hand osteoarthritis

Background

Hand pain is common in hand osteoarthritis (OA). Previous cohort studies reported stable average pain levels on the short to midterm. Subgroups with different pain trajectories have been found in knee OA. Similar subgroups of hand OA patients may exist. Knowledge of such subgroups in hand OA patients may help inform decisions for pain treatment.

Objectives

To determine and characterize subgroups with different hand pain trajectories over four years in hand OA patients.

Methods

Data from the ongoing HOSTAS (Hand OSTeoArthritis in Secondary care) cohort were used, collected from consecutive patients at the LUMC Rheumatology outpatient clinic with primary hand OA followed for four years. Hand pain measurements were collected annually starting at baseline with the AUSCAN pain questionnaire (range 0-20).

Development of pain over time was modelled using latent class growth analysis (LCGA), dividing the cohort into subgroups based on differences in pain development. The optimal model was selected based on the AIC, BIC, entropy and likelihood ratio test for models with n vs n-1 classes. LCGA requires ≥2 measurements per case, so patients with less were excluded.

Associations of LCGA classes with baseline demographics and factors associated with hand pain were analyzed using multinomial logistic regression.

Results

Of 538 participants, 484 completed the AUSCAN at ≥2 timepoints. Data of excluded patients were missing at random. Included and excluded patients were comparable. Of included participants 86% were women, mean (SD) age was 60.8 (8.5), 29% had erosive disease, median (IQR) symptom duration was 5.2 (1.9-12.2), 91% fulfilled the ACR criteria for hand OA. Mean AUSCAN pain score was 9.3 (4.3).

LCGA yielded five classes (Figure 1). Classes were characterized by different pain levels at baseline; mean level of pain remained stable over time. Classes with more pain were associated with more erosive disease, higher tender joint count, longer symptom duration, more comorbidities, worse AUSCAN function scores and worse SF-36 and HADS scores (Table 1).

Figure 1.

LCGA trajectories.

Trajectories of AUSCAN pain identified by latent class growth analysis. Least pain to most pain, named class 1 (pink), class 2 (red), class 3 (brown), class 4 (blue) and class 5 (green).

Table 1.

Multinomial logistic regression for associations with 5 LCGA classes

OR (95% CI)Baseline1 (N=37)2 (N=104)3 (N=171)4 (N=131)5 (N=41)Erosive disease11.20 (0.45-3.18)1.48 (0.55-4.03)1.23 (0.41-3.70)1.21 (0.30-4.87)Symptom duration, years;11.05 (0.97-1.13)1.09 (1.01-1.18)1.13 (1.04-1.22)1.12 (1.03-1.23)KL sum score11.01 (0.98-1.05)1.01 (0.98-1.05)1.02 (0.99-1.06)1.03 (0.99-1.08)Tender joint count11.17 (0.98-1.39)1.20 (1.00-1.44)1.28 (1.07-1.54)1.29 (1.06-1.57)AUSCAN function10.98 (0.90-1.08)1.08 (0.99-1.18)1.17 (1.06-1.30)1.31 (1.13-1.51)SF-36-PCS10.95 (0.89-1.02)0.90 (0.84-0.97)0.84 (0.77-0.91)0.81 (0.73-0.89)-MCS10.98 (0.90-1.06)0.96 (0.89-1.04)0.95 (0.87-1.03)0.90 (0.82-0.99)HADS-Depression11.28 (0.91-1.82)1.46 (1.02-2.09)1.50 (1.04-2.16)1.54 (1.04-2.28)-Anxiety11.09 (0.85-1.38)1.19 (0.93-1.54)1.19 (0.91-1.54)1.24 (0.92-1.65)No. Comorbidities11.64 (0.77-3.47)1.84 (0.86-3.90)2.22 (1.01-4.88)2.12 (0.89-5.06)

Multinomial logistic regression of variables associated with LCGA classes adjusted for baseline AUSCAN pain, age, sex and BMI. Class 1 = least pain, class 5 = most pain. SF-36 = Short Form-36. MCS = Mental component scale. PCS = Physical component scale. HADS = Hospital anxiety and depression scale. SF-36 scores are standardized on age, sex and nationality with mean 50 and SD 10.

Conclusion

Latent class growth analysis showed five subgroups with different pain trajectories in hand OA patients, with differing baseline pain and stable pain over time. These subgroups were associated with disease characteristics, number of comorbidities, psychological distress and health-related quality of life. This knowledge can help develop treatment for hand OA patients and inform them about the disease course.

Disclosure of Interests:

None declared

POS0123 NEUROPATHIC PAIN SYMPTOMS IN INFLAMMATORY HAND OSTEOARTHRITIS(OA) LOWERS HEALTH RELATED PHYSICAL QUALITY OF LIFE AND MAY REQUIRE ANOTHER APPROACH THAN ANTI-INFLAMMATORY TREATMENT

Background:

Pain is a common, difficult to manage symptom in hand osteoarthritis (OA). Multiple pain mechanisms may play a role in hand OA.

Objectives:

To investigate presence of neuropathic pain symptoms in patients with inflammatory hand OA, characteristics of those patients, their impact on health related quality of life (HR-QoL), and the influence of anti-inflammatory treatment on neuropathic pain symptoms.

Methods:

Data from a randomised, double-blind, placebo-controlled trial of prednisolone including 92 patients with hand OA fulfilling ACR criteria were used. At baseline patients had signs of synovial inflammation, a VAS finger pain of ≥30 mm and who flared ≥20 mm upon NSAID washout. The primary endpoint was VAS finger pain (0-100) at week 6.

Neuropathic pain symptoms were measured at baseline and week 6 using the validated painDETECT questionnaire, consisting of questions on pain quality, pain intensity over time and radiating pain. Scores range -1 to 38 and patients are classified as having unlikely (<13), indeterminate (13-18) and likely (>18) neuropathic pain. HR-QoL was measured with physical component scale (PCS) of Short-Form 36 (SF36; 0-100), comorbidities with the Self-administered Comorbidities Questionnaire (SCQ; 0-45), radiographic severity with Kellgren-Lawrence (KL) sum score (0-120), and treatment response with OMERACT-OARSI responder criteria.

Association of patient characteristics with neuropathic pain symptoms was analysed with univariate and multivariate ordinal logistic regression, with painDETECT as dependent variable. Association of neuropathic pain symptoms with HR-QoL was analysed with multivariate linear regression, adjusted for age, sex, BMI, VAS finger pain, SCQ score and KL sum score, with PCS as dependent variable. Response of neuropathic pain symptoms and VAS pain to prednisolone was analysed with generalised estimating equations. Association of neuropathic pain symptoms at baseline with response to treatment was analysed using χ2-tests and GEE.

Results:

91 patients had complete painDETECT data at baseline (mean painDETECT score 12.8 [SD 5.9]). Scores were <13 in 53%, 13-18 in 31% and >18 in 16%. Higher painDETECT score categories were associated with less radiographic damage, more comorbidities, female sex and higher VAS finger pain in multivariate analysis. (table 1)

Table 1.

Ordinal logistic regression with painDETECT categories as dependent variable

VariablesMean (SD) N=91 (100%)Odds ratio (95% CI)Age64 (9)0.96 (0.90 to 1.02)Female sex; N (%)72 (79%)3.84 (1.19 to 12.39)*BMI; median (SD)27 (24 to 29)0.97 (0.89 to 1.06)SCQ score; median (SD)2 (1 to 5)1.04 (1.04 to 1.36)*VAS finger pain53.8 (2.1)1.02 (1.00 to 1.04)*KL sum score37 (16)0.96 (0.93 to 1.00)*

*p<0.05. BMI = body mass index. SCQ = Self-administered comorbidities questionnaire. VAS = visual analog scale. KL= Kellgren-Lawrence.

Patients with painDETECT scores >18 had a lower HR-QoL (PCS -6.5 [95%CI -10.4 to -2.6]) than those with painDETECT scores <13.

PainDETECT scores remained unchanged throughout the trial in both prednisolone-treated and placebo-treated patients, and there was no between-group difference at week 6. VAS pain improved more in the prednisolone group than in the placebo group (mean between-group difference -16.5 [95%CI -26.1 to -6.9]) (figure 1). No association between the presence of neuropathic pain symptoms at baseline and OMERACT-OARSI response to treatment was found.

Conclusion:

Patients with inflammatory hand OA and additional neuropathic pain symptoms are more often female and have more comorbidities, and report a lower QoL, than those without. Neuropathic pain symptoms seem unresponsive to anti-inflammatory therapy. Clinicians should be aware of neuropathic pain symptoms in their patients as they might benefit from additional, specific treatment.

Acknowledgements:

The authors thank all patients for their participation in the HOPE study, and participating rheumatologists for inclusion of patients in the HOPE study. We also thank research nurses B.A.M.J. van Schie-Geyer and S. Wongsodihardjo, and technicians J.C. Kwekkeboom and E.I.H. van der Voort, for their contributions.

Disclosure of Interests:

Coen van der Meulen: None declared, Lotte van de Stadt: None declared, Féline Kroon: None declared, Marion Kortekaas: None declared, Annelies Boonen Speakers bureau: Lecture for UCB; paid to department., Consultant of: Yes. Advisory board meetings at Galapagos, Eli Lilly and Abvvie; paid to department., Grant/research support from: Yes. Grants by Celgene and Abbvie; paid to department., Stefan Böhringer: None declared, Marieke Niesters: None declared, Monique Reijnierse: None declared, Frits Rosendaal: None declared, Naghmeh Riyazi: None declared, M. Starmans: None declared, Franktien Turkstra: None declared, Jende van Zeben: None declared, Cornelia Allaart: None declared, Margreet Kloppenburg Consultant of: For Abbvie, Pfizer, Levicept, GlaxoSmithKline, Merck-Serono, Kiniksa, Flexìon, Galapagos, Jansen, CHDR and local investigator of industry-driven trial (Abbvie). All fees were paid to the institution., Grant/research support from: Grant by the Dutch Arthritis Society

POS1431 THE ASSOCIATION OF CLINICAL AND STRUCTURAL KNEE OSTEOARTHRITIS WITH PHYSICAL ACTIVITY IN THE MIDDLE-AGED POPULATION: THE NEO STUDY

Background:

Lack of physical activity in individuals with knee OA has shown to be associated with increased cardiovascular risk and mortality. Consequently, physical activity is a potential target for interventions in knee OA. However, most of the available studies concerning physical activity in individuals with knee OA were performed in relatively old populations with an inactive lifestyle. It is unclear how previous results can be generalized to other populations with different lifestyle and physical activity habits.

Objectives:

To investigate if knee OA is associated with lower physical activity in a general middle-aged Dutch population. Furthermore, to investigate the association of physical activity with patient reported outcomes such as knee pain and function, and health-related quality of life in individuals with knee OA.

Methods:

We used cross-sectional data from the Netherlands Epidemiology of Obesity (NEO) study, in which participants aged 45-65 years were included. Clinical knee OA was defined using the ACR criteria. Structural knee OA was defined on MRI using the modified criteria by Hunter et al. in a random subset of 1,285 individuals of our study population.

We assessed knee pain and function with the Knee injury and Osteoarthritis Score (KOOS), and health-related quality of life (HRQoL) with the Short Form (SF)-36. Physical activity (in Metabolic Equivalent of Task (MET) hours per week) was assessed using the Short Questionnaire to Assess Health-enhancing physical activity (SQUASH).

We used linear regression analyses to investigate 1) the association of knee OA with physical activity, and 2) of physical activity with knee pain, function, and HRQoL in participants with clinical knee OA. All analyses were adjusted for age, sex, body mass index (BMI), ethnicity, educational level and comorbidities. To account for possible information bias, we performed a sensitivity analysis to assess the association between clinical knee OA and physical activity measured by an accelerometer in a random subset of 15% of the study population.

Results:

Of 6,212 participants, we observed clinical knee OA in 14%, and structural knee OA in 12%. The general population characteristics and median physical activity of our study population are presented in Table 1. In comparison to participants without knee OA, participants with clinical knee OA had on average 9.60 (95% CI 3.70;15.50) MET hours per week more total physical activity (Figure 1). Structural knee OA was associated with 3.97 (-7.82; 15.76) MET hours per week more physical activity, compared with no structural knee OA.

Sensitivity analysis showed a weak positive association of clinical knee OA with physical activity measured by an accelerometer: 2.37 (-6.05; 10.80) MET hours per week more physical activity in participants with clinical knee OA, compared with participants without clinical knee OA.

In the subpopulation of participants with clinical knee OA, physical activity was not associated with knee pain, function or HRQoL.

Conclusion:

Knee OA was not associated with lower physical activity in this middle-aged Dutch population. This contrasts previous findings and warrants caution when generalizing physical activity outcomes to other populations. Furthermore, it stresses the need of more insight in the barriers and facilitators of physical activity in the middle-aged population.

Table 1.

Characteristics of the NEO study population

Alln = 6,214No clinical knee OA86%Clinical knee OA14%General population characteristics Age (year)55.7 (6.0)55.4 (6.1)57.5 (5.0) Sex (% women)555467 BMI (kg/m2)26.3 (4.4)26.1 (4.3)27.6 (5.1) Comorbidities (% present)242332Physical activity Total^ (MET-hours per week)118.8 (76.8;155.0)118.4 (76.6;154.4)123.5 (77.8;157.2)

Numbers represent mean (SD) or percentages. ^median (25th, 75th percentiles). Abbreviations: OA = osteoarthritis. BMI = Body Mass Index. MET = Metabolic Equivalent of Task.

Disclosure of Interests:

None declared

POS0258 REAL-TIME VERSUS STATIC SCORING IN MUSCULOSKELETAL ULTRASONOGRAPHY IN PATIENTS WITH INFLAMMATORY HAND OSTEOARTHRITIS

Background:

Ultrasound (US) is used in rheumatic musculoskeletal diseases (RMDs) such as hand osteoarthritis (OA) as outcome measure. Traditionally scoring is performed real-time, but central reading of static US images could avoid issues of inter-rater reliability. However, agreement between real-time and static assessment has not been studied

Objectives:

To study the agreement between real-time and static scoring of US in inflammatory hand OA.

Methods:

Ultrasound was performed of 30 joints obtained in 75 patients with hand osteoarthritis, treated with prednisolone or placebo in a randomized double-blind trial. Hand joints were assessed for synovial thickening, effusion, Doppler signal and osteophytes by ultrasound (score 0-3 per joint) at baseline and after treatment. Two ultrasonographers blinded for clinical data scored the live images together (simultaneously) in real-time. A consensus score for each joint was recorded. Representative images stored during scanning were scored by one ultrasonographer minimally 6 months after real-time scoring. For each patient, images of each visit were scored paired, with known chronological order.

Agreement between scoring methods was studied at joint level with quadratic weighted kappa. At patient level, intra-class correlations (ICC; mixed effect model, absolute agreement, with clustering taken into account) were calculated at both timepoints. ICCs were also calculated for the delta of sum scores. Responsiveness of scoring methods was analyzed with generalized estimating equations (GEE) with treatment as independent and ultrasonography findings as dependent variable.

Results:

Thirty-nine patients (52%) were treated with prednisolone and 36 (48%) were treated with placebo. Patient characteristics were well-balanced between treatment groups.

All patients had signs of synovial thickening and osteophytes as assessed by real-time ultrasonography, and almost all signs of effusion (99%) or a positive Doppler signal (95%) in at least one joint. Total ultrasonography sum score for osteophytes was high (mean 45 ±SD 12), whereas sum score was low for positive Doppler signal (mean 5.9 ±SD 4.4), with intermediate sum scores for synovial thickening and effusion (mean 16 ±SD 6.3 and 11 ±SD 6.0 respectively). Static sum scores were overall slightly higher (osteophytes mean 48 ±SD 10; Doppler mean 6.9 S±D 5.0; synovial thickening mean 20 ±SD 7.0 and effusion 13 ±SD 6.5)

Agreement at baseline was good to excellent at joint level (kappa 0.72-0.88) and moderate to excellent at patient level (ICC 0.59-0.86). Agreement for delta sum scores was poor to fair for synovial thickening and effusion (ICC 0.18 and 0.34 respectively), but excellent for Doppler signal (ICC 0.80) (Table 1).

Real-time ultrasonography showed responsiveness to prednisolone with a mean between-group difference of synovial thickening sum score of -2.5 (CI:-4.7 to-0.3). Static ultrasonography did not show a decrease in synovial thickening (Figure 1). No difference in ultrasonography scores was seen for the other ultrasonography features, neither with real-time nor static scoring.

Conclusion:

While cross-sectional agreement between real-time and static ultrasonography was good, agreement of delta sum scores was not and paired static ultrasonography measurement of synovial thickening did not show responsiveness to prednisone therapy where real-time ultrasonography did. Therefore, when using ultrasonography in clinical trials, real-time dynamic scoring should remain the standard.

Table 1.

Agreement on patient level

BaselineWeek 6Delta W6-BLICC (95% CI)ICC (95% CI)ICC (95% CI)Synovitis0.59 (0.26-0.76)0.58 (0.24-0.77)0.18 (0 - 0.40)Effusion0.84 (0.66-0.92)0.84 (0.75-0.89)0.34 (0.12-0.53)Osteophytes0.82 (0.50-0.92)0.78 (0.56-0.88)NDDoppler0.86 (0.75-0.92)0.91 (0.85-0.94)0.80 (0.70 -0.87)

ICC: intra-class correlation coefficient linear mixed model (random patient, fixed rating), absolute agreement. ND: Not Dertermined

Disclosure of Interests:

Lotte van de Stadt: None declared, Féline Kroon: None declared, Monique Reijnierse Grant/research support from: Dutch Arthritis Foundation, Désirée van der Heijde Consultant of: bbVie, Amgen, Astellas, AstraZeneca, Bayer, BMS, Boehringer Ingelheim, Celgene, Cyxone, Daiichi, Eisai, Eli-Lilly, Galapagos, Gilead, Glaxo-Smith-Kline, Janssen, Merck, Novartis, Pfizer, Regeneron, Roche, Sanofi, Takeda, UCB Pharma, Frits Rosendaal: None declared, Naghmeh Riyazi: None declared, R. de Slegte: None declared, Jende van Zeben: None declared, Cornelia Allaart: None declared, Margreet Kloppenburg Consultant of: Abbvie, Pfizer, Levicept, GlaxoSmithKline, Merck-Serono, Kiniksa, Flexion, Galapagos, Jansen, CHDR, Grant/research support from: MI-APPROACH, Marion Kortekaas: None declared

AB0430 MORTALITY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS AND NEUROPSYCHIATRIC SYMPTOMS

Background:

Little is known about mortality in patients with systemic lupus erythematosus (SLE) presenting with neuropsychiatric (NP) symptoms.

Objectives:

We aimed to evaluate all-cause and cause-specific mortality in patients with SLE and NP symptoms.

Methods:

All patients with the clinical diagnosis of SLE of 18 years and older that visited the tertiary referral NPSLE clinic of the Leiden University Medical Center between 2007-2018 and signed informed consent were included in this study. Patients were classified as NPSLE if NP symptoms were attributed to SLE and immunosuppressive or anticoagulant therapy was initiated, otherwise patients were classified as non-NPSLE. Municipal registries were checked for current status (alive/deceased). Electronical medical files were studied for clinical characteristics and cause of death. Standardized mortality ratios (SMRs) and 95% confidence intervals were calculated using data from the general Dutch population. In addition, a rate ratio (RR) was calculated using direct standardization to compare mortality in NPSLE with non-NPSLE patients.

Results:

351 patients with the clinical diagnosis of SLE were included, of which 149 patients were classified as NPSLE (42.5%). Compared with the general population, mortality was increased five times in NPSLE (SMR 5.0, 95% CI: 2.6-8.5) and nearly four times in non-NPSLE patients (SMR 3.7, 95% CI: 2.2-6.0), as shown in Table 1. Risk of death due to cardiovascular disease (CVD) was increased in non-NPSLE patients (SMR 6.2, 95% CI: 2.0-14.6) and an increased risk of death to infections was present in both NPSLE and non-NPSLE patients ((SMR 29.9, 95% CI: 3.5 – 105) and SMR 91.3 (95% CI: 18.8 – 266) respectively). However, mortality did not differ between NPSLE and non-NPSLE patients (RR 1.0, 95% CI: 0.5 – 2.0).

Table 1.

All-cause mortality in SLE patients presenting with neuropsychiatric symptoms attributed to SLE (NPSLE) or to other causes (non-NPSLE)

NPSLE(N = 149)Non-NPSLE(N = 202)Deaths (N, %)13 (8.7)17 (8.4)Age at death (median, range)49 (32 – 79)59 (20 – 89)Follow-up time (years)9061047Crude mortality rate (per 1000 PY)14.316.2All-cause mortality*Female5.5 (2.8 – 9.6)3.4 (1.9 – 5.7)Male2.3 (0.1 - 12.8)6.2 (1.3 – 18.2)Combined5.0 (2.6 – 8.5)3.7 (2.2 – 6.0)

*Standardized mortality ratio, ratio of the observed and expected number of deaths

Conclusion:

Mortality was increased in both NPSLE and non-NPSLE patients in comparison with the general population, but there was no difference in mortality between NPSLE and non-NPSLE patients. Risk of death due to infections was increased in both groups.

Disclosure of Interests:

Rory Monahan: None declared, Rolf Fronczek: None declared, Jeroen Eikenboom: None declared, Huub Middelkoop: None declared, L.J.J. Beaart- van de Voorde: None declared, Gisela Terwindt: None declared, Nic van der Wee: None declared, Frits Rosendaal: None declared, Thomas Huizinga Grant/research support from: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Consultant of: Ablynx, Bristol-Myers Squibb, Roche, Sanofi, Margreet Kloppenburg: None declared, G.M. Steup-Beekman: None declared

FRI0413 THE ASSOCIATION OF OBESITY WITH OSTEOARTHRITIS IS LIMITEDLY MEDIATED BY HYPERTENSION AND SUBCLINICAL ATHEROSCLEROSIS

Background:

Obesity-related metabolic dysregulation may lead to atherosclerotic vascular changes. It has been hypothesized that a compromised blood flow may cause detrimental changes to the subchondral bone and decrease nutrient supply to the cartilage. To which extent atherosclerosis may explain the association between obesity and OA has not been investigated.

Objectives:

To investigate the role of hypertension and subclinical atherosclerosis (carotid intima-media thickness (IMT), popliteal vessel wall thickness (VWT), aortic pulse wave velocity (PWV)) as mediators of the association of obesity with hand and knee OA.

Methods:

We used cross-sectional data from the population-based NEO study, excluding participants with concomitant rheumatic diseases (n = 323), resulting in 6,334 participants. Clinical hand and knee OA were defined by the ACR classification criteria. Popliteal VWT was assessed on MR images in a subpopulation (n = 1,095), using VesselMASS for semi-automated detection of the vessel wall boundaries. Aortic PWV was estimated on abdominal velocity-encoded MR images in a subpopulation (n = 2,580). Carotid IMT was assessed by ultrasonography. Hypertension was defined as a systolic blood pressure ≥ 130 mmHg or a diastolic blood pressure ≥ 85 mmHg, or using antihypertensive medication. Continuous variables were standardized (mean 0, standard deviation 1). Associations between BMI and OA were assessed with logistic regression analyses, adjusted for age, sex and education. Subsequently, possible mediators were added to the model and the percentage mediation was calculated.

Results:

The population consisted of 55% women, with a mean (SD) age of 56 (6) years and BMI of 26 (4) kg/m2. Hand OA was present in 8% and knee OA in 10% of participants. Hypertension was present in 61.6% of participants. Mean (SD) carotid IMT was 0.62 (0.09) mm, popliteal VWT was 0.53 (0.05) mm, and aortic PWV was 6.56 (1.30) m/s. BMI was associated with the presence of hand OA and knee OA (table 1). BMI was positively associated with hypertension and carotid IMT, but not with popliteal VWT and aortic PWV. The association between BMI and hand OA was partially mediated by hypertension (5.9%) and carotid IMT (10.6%). Hypertension (4.9%) showed a weak mediating effect for the association between BMI and knee OA.

Table 1.

Mediation of the association of BMI with OA by hypertension and atherosclerosis

Hand OAOR (95% CI)MediatorOR/β (95% CI)Hand OAOR (95% CI)Mediation% (95% CI)BMI1.21 (1.08; 1.36)1.72 (1.56; 1.90)1.20 (1.06; 1.36)5.9 (3.4; 17.4)Hypertension1.15 (0.82; 1.60)BMI1.21 (1.08; 1.36)0.23 (0.19; 0.27)1.19 (1.05; 1.34)10.6 (6.2; 30.5)Carotid IMT1.09 (0.94; 1.25)BMI1.56 (1.17; 2.08)0.01 (-0.06; 0.09)1.55 (1.16; 2.07)0.5 (0.3; 1.7)Popliteal VWT1.14 (0.84; 1.55)BMI1.41 (1.15; 1.73)0.05 (-0.01; 0.11)1.41 (1.15; 1.73)0.7 (0.4; 2.0)Aorta PWV1.04 (0.81; 1.33)Knee OAOR (95% CI)MediatorOR/β (95% CI)Knee OAOR (95% CI)BMI1.46 (1.32; 1.62)1.70 (1.55; 1.87)1.43 (1.29; 1.59)4.9 (3.7; 7.0)Hypertension1.25 (0.93; 1.67)BMI1.46 (1.32; 1.62)0.24 (0.20; 0.27)1.47 (1.33; 1.62)-1.6 (-2.4; -1.2)Carotid IMT0.97 (0.86; 1.09)BMI1.20 (0.88; 1.64)0.03 (-0.04; 0.11)1.21 (0.89; 1.64)-0.5 (-7.4; 13.3)Popliteal VWT0.95 (0.74; 1.24)BMI1.37 (1.12; 1.67)0.05 (-0.00; 0.11)1.37 (1.12; 1.67)-0.5 (-1.8; -0.3)Aorta PWV0.96 (0.76; 1.21)

Results are based on analyses weighted towards the BMI distribution of the general population (n = 6,334). Analysis regarding popliteal VWT (n = 1,095) and aorta PWV (n = 2,580) were assessed in a subpopulation Continuous variables were standardized (mean 0, SD 1), SD BMI = 4.41, SD carotid IMT = 0.09, SD popliteal VWT = 0.05, SD aorta PWV = 1.30.

Conclusion:

We assessed whether the association between BMI and OA was mediated by hypertension and atherosclerosis. Our results imply that either such mediation is absent or trivial, or that the atherosclerosis measures were too weak.

Disclosure of Interests:

None declared

Recommendations for authors of manuscripts reporting inhibitor cases developed in previously treated patients with hemophilia: communication from the SSC of the ISTH

Aim The scope of this recommendation is to provide guidance for reporting of inhibitor cases in previously treated patients (PTPs) with hemophilia A. This guidance is intended to improve transparency and completeness of reporting of observed events; it does not cover planning, executing or analyzing original studies aimed at the assessment of inhibitor rates. Recommendation We recommend that for each case of inhibitor development reported in a published paper, a paragraph or a table is included in the main publication reporting as a minimum the underlined data fields in Table . We recommend transparent reporting when any of the suggested information is not available. We recommend that particular care is used in reporting the timeline of events by clearly identifying a reference time-point. We suggest that journals in the field adopt this guidance as instructions for the authors and as a guide for reviewers. Conclusion Development of inhibitors in PTPs is a very rare event. Standardized reporting of inhibitor characteristics will contribute to generating a body of evidence otherwise not available. Case by case reporting of the recommended data elements may shed light on the natural history and risk factors of inhibitor development in PTPs and be useful for tailoring care in similar future cases.

Resistance to APC and SHBG levels during use of a four-phasic oral contraceptive containing dienogest and estradiol valerate: a randomized controlled trial

BACKGROUND

The use of combined oral contraceptives is associated with a 3- to 6-fold increased risk of venous thrombosis. This increased risk depends on the estrogen dose as well as the progestogen type of combined oral contraceptives. Thrombin generation-based activated protein C resistance (APC resistance) and sex hormone-binding globulin (SHBG) levels predict the thrombotic risk of a combined hormonal contraceptive. Recently, a four-phasic oral contraceptive containing dienogest (DNG) and estradiol valerate (E2V) has been marketed. The aim of this study was to evaluate the thrombotic risk of the DNG/E2V oral contraceptive by comparing APC resistance by measuring normalized APC sensitivity ratios (nAPCsr) and SHBG levels in users of oral contraceptives containing dienogest and estradiol valerate (DNG/E2V) and oral contraceptives containing levonorgestrel and ethinyl estradiol (LNG/EE).

METHODS

We conducted a single-center, randomized, open label, parallel-group study in 74 women using DNG/E2V or LNG/EE, and measured nAPCsr and SHBG levels in every phase of the regimen of DNG/E2V.

RESULTS

During the pill cycle SHBG levels did not differ between DNG/E2V users and LNG/EE users. nAPCsr levels were overall slightly lower in DNG/E2V users than in LNG/EE users, mean difference -0.44 (95% CI, -1.04 to 0.17) for day 2, -0.20 (95% CI, -0.76 to 0.37) for day 7, -0.27 (95% CI, -0.81 to 0.28) for day 24 and -0.34 (95% CI, -0.91 to 0.24) for day 26.

CONCLUSION

No statistical significant differences in nAPCsr and SHBG levels were found between users of the oral contraceptive containing DNG/E2V and LNG/EE, suggesting a comparable thrombotic risk.

Sex hormone-binding globulin as a marker for the thrombotic risk of hormonal contraceptives

BACKGROUND

It takes many years to obtain reliable values for the risk of venous thrombosis of hormonal contraceptive users from clinical data. Measurement of activated protein C (APC) resistance via thrombin generation is a validated test for determining the thrombogenicity of hormonal contraceptives. Sex hormone-binding globulin (SHBG) might serve as a marker for the risk of venous thrombosis, and can be easily and rapidly measured in routine laboratories.

OBJECTIVE

To determine whether SHBG is a useful marker for the thrombotic risk of hormonal contraceptive users by comparing plasma SHBG levels with normalized APC sensitivity ratio (nAPCsr) values and thrombosis risks reported in the recent literature.

METHODS

We conducted an observational study in 262 users of different contraceptives, and measured nAPCsr and SHBG levels.

RESULTS

Users of contraceptives with a higher risk of causing venous thrombosis, i.e. combined hormonal contraceptives containing desogestrel, cyproterone acetate or drospirenone, and the transdermal patch, had higher SHBG levels than users of combined hormonal contraceptives containing levonorgestrel, which carry a lower thrombosis risk. Users of the patch had the highest SHBG levels, with a mean difference of 246 nmol L(-1) (95% confidence interval 179-349) from that in users of levonorgestrel-containing combined hormonal contraceptives. SHBG levels were positively associated with both the nAPCsr and the risks of venous thrombosis reported in the recent literature.

CONCLUSION

SHBG is a useful marker with which to estimate the thrombotic safety of a preparation.

Making a bad thing worse: Effects of communication of results of an epidemiological study after an aviation disaster

Cognitions attributing health complaints to disaster exposure are associated with more severe health complaints and are therefore a promising target for interventions. Little is known about the best strategy to modify such cognitions following exposure to a technological disaster at the community level. In 1992, a Boeing 747 crashed in a residential area in Amsterdam, the Netherlands. Persisting rumours about the possible toxic cargo of the plane led to increasing health concerns among the residents and rescue workers involved in the disaster. The current study investigates (a) the effectiveness of providing information on the health consequences of exposure to the aviation disaster to residents and rescue workers with varying degrees of exposure to the disaster, and (b) individual characteristics which may moderate the effectiveness of the health information provided. A total of 1019 rescue workers and 453 residents involved with varying degrees in the disaster participated in an epidemiological investigation and 1736 rescue workers and 339 residents, all involved, participated in an individual medical examination. Participants were assessed at baseline and 6 weeks after communication of the results of the epidemiological study. Main outcome measures evaluated health anxiety, somatic sensitivity, reassurance by a physician, psychopathology, post-traumatic stress symptoms, fatigue and quality of life. All participants reported elevated levels of psychopathology and fatigue, increased anxiety and uncertainties about their health 6 weeks after communication of the study results irrespective of the degree of exposure to the disaster. In particular, the conviction that health complaints were caused by toxic exposure was related to more severe health complaints and worries in both rescue workers and residents. Our study shows that communication about the health consequences of exposure to an aviation disaster at the community level has no symptom reducing or reassuring effects. Tailoring of the communication to individual characteristics such as existing expectancies may enhance its impact.

A novel anticoagulant activity assay of tissue factor pathway inhibitor I (TFPI)

Tissue factor (TF) pathway inhibitor I (TFPI) is the physiological inhibitor of TF-induced blood coagulation. Circulating blood contains full-length TFPI and TFPI truncated at the C-terminal end. Previous studies have shown that full-length TFPI exerts a stronger anticoagulant effect on diluted prothrombin time (DPT) than truncated TFPI, and it has been suggested that full-length TFPI is biologically more important in vivo. The objective of this study was to develop and validate an assay of TFPI anticoagulant activity. TFPI anticoagulant activity was assayed using a modified DPT assay. Plasmas were incubated in the absence and the presence of TFPI-blocking antibodies. Results were expressed as a ratio with the clotting time in the presence of anti-TFPI as the denominator. The ratio was normalized against a ratio obtained with a reference plasma. The assay was compared with assays of TFPI free antigen, total antigen, and bound TFPI, and TFPI chromogenic substrate activity. We performed all tests in 436 healthy individuals. The normalized TFPI anticoagulant ratio was strongly associated with TFPI free antigen (r = 0.73) but was weakly associated with TFPI chromogenic substrate activity (r = 0.46), TFPI total antigen (r = 0.48), and bound TFPI (r = 0.30). TFPI chromogenic substrate activity was strongly associated with TFPI total antigen (r = 0.73). We have developed a novel assay of TFPI anticoagulant activity in plasma, which may be considered a functional assay of full-length TFPI. Further studies are needed to establish the role of TFPI anticoagulant activity for thrombotic disorders.

Factor V Leiden: the venous thrombotic risk in thrombophilic families

Factor V Leiden (FVL) leads to a sevenfold increased risk of venous thrombosis and is present in 50% of individuals from families referred because of unexplained familial thrombophilia. We assessed the association of FVL with venous thromboembolism (VTE) in 12 thrombophilic families of symptomatic probands with FVL in a retrospective follow-up study. We screened 182 first- and second-degree relatives of the 12 unrelated propositi for the FVL mutation and the occurrence of VTE. The incidence rate of VTE in carriers of FVL (0.56%/year) was about six times the incidence for the Dutch population (0.1%/year). The incidence rate in non-carriers also appeared to be higher (0.15% per year). At the age of 50 years, the probability of not being affected by VTE was reduced to 75% for carriers and to 93% for non-carriers (P = 0.009). Identification of carriers of FV Leiden may be worthwhile in young symptomatic individuals and their relatives with a strong positive family history of venous thromboembolism or a history of recurrent venous thrombosis who may be at risk (e.g. pregnancy, use of oral contraceptives). After adjustment for prothrombin G20210A (present in two families), even higher thrombotic incidence rates were found in carriers and non-carriers of FVL. This makes the presence of other unknown prothrombotic risk factors more probable in these families.

Thrombophilia

Thrombophilia is now considered a multicausal disease, with an interplay of acquired and genetic risk factors. Recent studies have shown that patients with the 20210 A prothrombin mutation display remarkably similar characteristics compared with patients with Factor V Leiden mutation. It is evident that neither the Factor V Leiden mutation nor the 20210 A prothrombin mutation is a major risk factor for myocardial infarction or stroke, unless accompanied by other classical risk factors, including diabetes mellitus, hypertension and smoking. Finally, the homozygous form of the thermolabile methylenetetrahydrofolate reductase gene, although leading to elevated homocysteine levels, seems not to represent a genetic risk factor for venous thrombosis.