Background incidence rates of health outcomes in populations at risk for Lyme disease using US administrative claims data

BACKGROUND

Background incidence rates (IRs) of health outcomes in Lyme disease endemic regions are useful to contextualize events reported during Lyme disease vaccine clinical trials or post-marketing. The objective of this study was to estimate and compare IRs of health outcomes in Lyme disease endemic versus non-endemic regions in the US during pre-COVID and COVID era timeframes.

METHODS

IQVIA PharMetrics® Plus commercial claims database was used to estimate IRs of 64 outcomes relevant to vaccine safety monitoring in the US during January 1, 2017-December 31, 2019 and January 1, 2020-December 31, 2021. Analyses included all individuals aged ≥ 2 years with ≥ 1 year of continuous enrollment. Outcomes were defined by International Classification of Diseases Clinical Modification, 10th Revision (ICD-10-CM) diagnosis codes. IRs and 95 % confidence intervals (CIs) were calculated for each outcome and compared between endemic vs. non-endemic regions, and pre-COVID vs. COVID era using IR ratios (IRR).

RESULTS

The study population included 8.7 million (M) in endemic and 27.8 M in non-endemic regions. Mean age and sex were similar in endemic and non-endemic regions. In both study periods, the IRs were statistically higher in endemic regions for anaphylaxis, meningoencephalitis, myocarditis/pericarditis, and rash (including erythema migrans) as compared with non-endemic regions. Conversely, significantly lower IRs were observed in endemic regions for acute kidney injury, disseminated intravascular coagulation, heart failure, myelitis, myopathies, and systemic lupus erythematosus in both study periods. Most outcomes were statistically less frequent during the COVID-era.

CONCLUSION

This study identified potential differences between Lyme endemic and non-endemic regions of the US in background IRs of health conditions during pre-COVID and COVID era timeframes to inform Lyme disease vaccine safety monitoring. These regional and temporal differences in background IRs should be considered when contextualizing possible safety signals in clinical trials and post-marketing of a vaccine targeted at Lyme disease prevention.

Risk of cardiovascular events after an exacerbation of chronic obstructive pulmonary disease: results from the EXACOS-CV cohort study using the PHARMO Data Network in the Netherlands

BACKGROUND

People living with chronic obstructive pulmonary disease (COPD) have an increased risk of experiencing cardiovascular (CV) events, particularly after an exacerbation. Such CV burden is not yet known for incident COPD patients. We examined the risk of severe CV events in incident COPD patients in periods following either moderate and/or severe exacerbations.

METHODS

Persons aged ≥ 40 years with an incident COPD diagnosis from the PHARMO Data Network were included. Exposed time periods included 1-7, 8-14, 15-30, 31-180 and 181-365 days following an exacerbation. Moderate exacerbations were defined as those managed in outpatient settings; severe exacerbations as those requiring hospitalisation. The outcome was a composite of time to first severe CV event (acute coronary syndrome, heart failure decompensation, cerebral ischaemia, or arrhythmia) or death. Hazard ratios (HR) were estimated for association between each exposed period and outcome.

RESULTS

8020 patients with newly diagnosed COPD were identified. 2234 patients (28%) had ≥ 1 exacerbation, 631 patients (8%) had a non-fatal CV event, and 461 patients (5%) died during a median follow-up of 36 months. The risk of experiencing the composite outcome was increased following a moderate/severe exacerbation as compared to time periods of stable disease [range of HR: from 15.3 (95% confidence interval 11.8-20.0) in days 1-7 to 1.3 (1.0-1.8) in days 181-365]. After a moderate exacerbation, the risk was increased over the first 180 days [HR 2.5 (1.3-4.8) in days 1-7 to 1.6 (1.3-2.1) in days 31-180]. After a severe exacerbation, the risk increased substantially and remained higher over the year following the exacerbation [HR 48.6 (36.9-64.0) in days 1-7 down to 1.6 (1.0-2.6) in days 181-365]. Increase in risk concerned all categories of severe CV events.

CONCLUSIONS

Among incident COPD patients, we observed a substantial risk increase of severe CV events or all-cause death following either a moderate or severe exacerbation of COPD. Increase in risk was highest in the initial period following an exacerbation. These findings highlight the significant cardiopulmonary burden among people living with COPD even with a new diagnosis.

Mating allocations in Holstein combining genomic information and linear programming optimization at the herd level

In this study, we explored mating allocation in Holstein using genomic information for 24,333 Holstein females born in Denmark, Finland, and Sweden. We used 2 data sets of bulls: the top 50 genotyped bulls and the top 25 polled genotyped bulls on the Nordic total merit scale. We used linear programming to optimize economic scores within each herd, considering genetic level, genetic relationship, semen cost, the economic impact of genetic defects, polledness, and β-casein. We found that it was possible to reduce genetic relationships and eliminate expression of genetic defects with minimal effect on the genetic level in total merit index. Compared with maximizing only Nordic total merit index, the relative frequency of polled offspring increased from 13.5 to 22.5%, and that of offspring homozygous for β-casein (A2A2) from 66.7 to 75.0% in one generation, without any substantial negative impact on other comparison criteria. Using only semen from polled bulls, which might become necessary if dehorning is banned, considerably reduced the genetic level. We also found that animals carrying the polled allele were less likely to be homozygous for β-casein (A2A2) and more likely to be carriers of the genetic defect HH1. Hence, adding economic value to a monogenic trait in the economic score used for mating allocation sometimes negatively affected another monogenetic trait. We recommend that the comparison criteria used in this study be monitored in a modern genomic mating program.

Decreased levels of discomfort in repeatedly handled mice during experimental procedures, assessed by facial expressions

Mice are the most commonly used laboratory animal, yet there are limited studies which investigate the effects of repeated handling on their welfare and scientific outcomes. Furthermore, simple methods to evaluate distress in mice are lacking, and specialized behavioral or biochemical tests are often required. Here, two groups of CD1 mice were exposed to either traditional laboratory handling methods or a training protocol with cup lifting for 3 and 5 weeks. The training protocol was designed to habituate the mice to the procedures involved in subcutaneous injection, e.g., removal from the cage, skin pinch. This protocol was followed by two common research procedures: subcutaneous injection and tail vein blood sampling. Two training sessions and the procedures (subcutaneous injection and blood sampling) were video recorded. The mouse facial expressions were then scored, focusing on the ear and eye categories of the mouse grimace scale. Using this assessment method, trained mice expressed less distress than the control mice during subcutaneous injection. Mice trained for subcutaneous injection also had reduced facial scores during blood sampling. We found a clear sex difference as female mice responded to training faster than the male mice, they also had lower facial scores than the male mice when trained. The ear score appeared to be a more sensitive measure of distress than the eye score, which may be more indicative of pain. In conclusion, training is an important refinement method to reduce distress in mice during common laboratory procedures and this can best be assessed using the ear score of the mouse grimace scale.

Emphasis on resilience in dairy cattle breeding: Possibilities and consequences

This study aimed to investigate dairy cattle breeding goals with more emphasis on resilience. We simulated the consequences of increasing weight on resilience indicators and an assumed true resilience trait (TR). Two environments with different breeding goals were simulated to represent the variability of production systems across Europe. Ten different scenarios were stochastically simulated in a so-called pseudogenomic simulation approach. We showed that many modern dairy cattle breeding goals most likely have negative genetic gain for TR and promising resilience indicators such as the log-transformed, daily deviation from the lactation curve (LnVAR). In addition, there were many ways of improving TR by increasing the breeding goal weight of different resilience indicators. The results showed that adding breeding goal weight to resilience indicators, such as body condition score and LnVAR, could reverse the negative trend observed for resilience indicators. Loss in the aggregate genotype calculated with only current breeding goal traits was 12 to 76%. This loss was mainly due to a reduction in genetic gain in milk production. We observed higher genetic gain in beef production, fertility, and udder health when breeding for more resilience, but from an economical point of view, this was not high enough to compensate for the reduction in genetic gain in milk production. The highest genetic gain in TR was obtained when adding the highest breeding goal weight to LnVAR or TR, both with 0.29 genetic standard deviation units. The indicators we used, body condition score and LnVAR, can be measured on a large scale today with relatively cheap methods, which is crucial if we want to improve these traits through breeding. Economic values for resilience have to be estimated to find the most optimal breeding goal for a more resilient dairy cow in the future.

POS0547 THE ADVANTAGE OF TIGHT CONTROL AND TREAT TO TARGET IN NEW-ONSET RA PATIENTS IN DAILY RHEUMATOLOGY PRACTICE: RESULTS FROM A CONTEMPORARY UNIVERSITY CLINIC INCEPTION COHORT

Background

Since 2018, all patients with new-onset rheumatoid arthritis (RA) at the Department of Rheumatology, Skane University Hospital, Lund, Sweden, are offered to participate in a ”tight control” and ”treat to target” (TC+T2T) follow-up strategy. This strategy includes regular follow-up visits to a rheumatologist (at diagnosis and 3, 6, 12, 18, 24 months) plus physical/telephone consultations with a rheumatology nurse between physician visits, both with disease activity assessments and, if needed, adjustment/intensification of anti-rheumatic treatment aiming for remission.

Objectives

To explore the possible advantages of integrating this TC+T2T strategy over routine care, aiming more systematically for remission (DAS28<2,6 or CDAI≤2,8), in clinical practice of new-onset RA.

Methods

Patients followed by the TC+T2T strategy were compared to new-onset RA patients followed according to routine care at the same department and during the same period. Data on disease and treatment characteristics, as well as outcome measures during follow-up were retrieved from the Swedish Rheumatology Quality register (SRQ). In total, 156 patients with at least 3 months follow-up between 2018 and 2021 were included; 95 followed according to the TC+T2T strategy and 61 according to routine care. Percentage females/mean age at onset/mean symptom duration at diagnosis were 79%/57 years/4 months (TC+T2T) and 62%/62 years/7 months (routine care). The change in DAS28 and CDAI from baseline to 12 months follow-up were compared between the two strategies by linear regression analyses, adjusted for sex, age, symptom duration, and DAS28 or CDAI, respectively, at baseline. In addition, changes in patient-reported outcomes (fatigue, pain and HAQ) are calculated.

Results

Disease and treatment characteristics at inclusion (diagnosis) are summarized in the Table 1.

Table 1.TC+T2T group (n=95)Controls (n=61)Swollen 28 joint count,6,6 (4)5,1 (5)Tender 28 join count8,2 (5)6,2 (6)ESR48,1 (29)37,7 (25)CRP21,3 (29)16,9 (23)DAS285,5 (1)4,6 (1)CDAI24,5 (11)18,3 (11)HAQ1,01 (0,6)0,98 (0,7)Fatigue (VAS)50,1 (29)46,6 (30)Pain (VAS)57,9 (24)47,3(30)ACPA positive (%)77%53%Radiographic changes in hands or feet at inclusion (%)12%18%Smoker (%)16%7%Methotrexate started at inclusion (%)78%85 %Prednisolone started at inclusion (%)100%97%

Mean and standard deviation (SD) if not otherwise stated.

The TC+T2T strategy resulted in greater improvements in DAS28 and CDAI scores from inclusion to 12 months follow up (p=0,025 and p=0,026; respectively; Figure 1). Beyond improvements in DAS28 and CDAI, a significant decrease in patient-reported outcomes (fatigue and pain) during 12 months from diagnosis was observed (Figure 1).

Conclusion

Compared to routine rheumatology practice, the implementation of a ”tight control” and ”treat to target” strategy resulted in a greater improvement in disease activity and an early and sustained improvement in patient-reported outcomes. Our results suggest that this type of strategy should be integrated into daily clinical practice of new-onset RA.

Disclosure of Interests

Jon Thorkell Einarsson: None declared, Katarina Friberger Pajalic: None declared, Caroline Bengtsson: None declared, Elisabeth Mogard: None declared, Elisabet Lindqvist: None declared, Carmen Roseman: None declared, Olafur Palsson: None declared, Johan K Wallman Consultant of: Consultant of AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: Research support from AbbVie, Amgen, Eli Lilly, Novartis, Pfizer.

Tor Olofsson Consultant of: consultant of MSD, Meliha C Kapetanovic Consultant of: Abbvie, Pfizer, GSK, Grant/research support from: unrestricted grants from Pfizer and Roche.

Manual therapy versus advice to stay active for nonspecific back and/or neck pain: a cost-effectiveness analysis

BACKGROUND

Low back and neck pain are the most common musculoskeletal disorders worldwide, and imply suffering and substantial societal costs, hence effective interventions are crucial. The aim of this study was to evaluate the cost-effectiveness of manual therapy compared with advice to stay active for working age persons with nonspecific back and/or neck pain.

METHODS

The two interventions were: a maximum of 6 manual therapy sessions within 6 weeks, including spinal manipulation/mobilization, massage and stretching, performed by a naprapath (index group), respectively information from a physician on the importance to stay active and on how to cope with pain, according to evidence-based advice, at 2 occasions within 3 weeks (control group). A cost-effectiveness analysis with a societal perspective was performed alongside a randomized controlled trial including 409 persons followed for one year, in 2005. The outcomes were health-related Quality of Life (QoL) encoded from the SF-36 and pain intensity. Direct and indirect costs were calculated based on intervention and medication costs and sickness absence data. An incremental cost per health related QoL was calculated, and sensitivity analyses were performed.

RESULTS

The difference in QoL gains was 0.007 (95% CI - 0.010 to 0.023) and the mean improvement in pain intensity was 0.6 (95% CI 0.068-1.065) in favor of manual therapy after one year. Concerning the QoL outcome, the differences in mean cost per person was estimated at - 437 EUR (95% CI - 1302 to 371) and for the pain outcome the difference was - 635 EUR (95% CI - 1587 to 246) in favor of manual therapy. The results indicate that manual therapy achieves better outcomes at lower costs compared with advice to stay active. The sensitivity analyses were consistent with the main results.

CONCLUSIONS

Our results indicate that manual therapy for nonspecific back and/or neck pain is slightly less costly and more beneficial than advice to stay active for this sample of working age persons. Since manual therapy treatment is at least as cost-effective as evidence-based advice from a physician, it may be recommended for neck and low back pain. Further health economic studies that may confirm those findings are warranted. Trial registration Current Controlled Trials ISRCTN56954776. Retrospectively registered 12 September 2006, http://www.isrctn.com/ISRCTN56954776 .

Mating allocations in Nordic Red Dairy Cattle using genomic information

In this study, we compared mating allocations in Nordic Red Dairy Cattle using genomic information. We used linear programming to optimize different economic scores within each herd, considering genetic level, semen cost, the economic impact of recessive genetic defects, and genetic relationships. We selected 9,841 genotyped females born in Denmark, Finland, or Sweden in 2019 for mating allocations. We used 2 different pedigree relationship coefficients, the first tracing the pedigree 3 generations back from the parents of the potential mating and the second based on all available pedigree information. We used 3 different genomic relationship coefficients, 1 SNP-by-SNP genomic relationship and 2 based on shared genomic segments. We found high correlations (≥0.83) between the pedigree and genomic relationship measures. The mating results showed that it was possible to reduce the different genetic relationships between parents with minimal effect on genetic level. Including the cost of known recessive genetic defects eliminated expression of genetic defects. It was possible to reduce genomic relationships between parents with pedigree measures, but it was best done with genomic measures. Linear programming maximized the economic score for all herds studied within seconds, which means that it is suitable for implementation in mating software to be used by advisors and farmers.

Sinonasal outcome test-22 and peak nasal inspiratory flow - valuable tools in obstructive sleep apnoea

BACKGROUND

Sinonasal complaints contribute to low adherence to continuous positive airway pressure (CPAP) treatment. We aimed to investigate sinonasal health in obstructive sleep apnoea (OSA) patients, using the sinonasal outcome test-22 (SNOT-22), and to analyse whether SNOT-22 is affected by CPAP adherence. We also aimed to investigate whether peak nasal inspiratory flow (PNIF) was able to predict adherence to CPAP.

METHODS

The study population comprised 197 OSA patients (60 females) initiating CPAP treatment. The SNOT-22, PNIF and the Epworth Sleepiness Scale were assessed at baseline and follow-up. One-night polygraphy, the Hospital Anxiety and Depression Scale, peak expiratory flow and health-related issues were assessed at baseline. At follow-up, the patients were categorised into adherent (more than 4 hours/night) and non-adherent (less than 4 hours/night) to CPAP treatment.

RESULTS

The average time for following up CPAP treatment was (mean plus or minus SD) 24.0 plus or minus 23.9 days and it did not differ significantly between the groups. The SNOT-22 score was elevated among all OSA patients, 36.1 plus or minus 19.4. There was a larger improvement in the SNOT-22 score at follow-up among adherent CPAP users compared with non-adherent users (-10.4 plus or minus 13.9 vs. -3.2 plus or minus 15.4). A PNIF value of less than 100 litres/min increased the risk of non-adherence to CPAP with an adjusted odds ratio (OR) of 2.40 ((95% CI 1.16-5.00)).

CONCLUSIONS

The SNOT-22 was elevated in patients with OSA, indicating a considerable sinonasal disease burden. The SNOT-22 improved with good CPAP adherence. A low PNIF value was able to predict poor CPAP adherence. Both the SNOT-22 and PNIF can be valuable tools in the evaluation of OSA patients and in the management of CPAP treatment.

Infections in patients with multiple sclerosis: A national cohort study in Sweden

BACKGROUND

Multiple sclerosis (MS) patients have an increased risk of infections, but few population-based studies have reported infections occurring in MS in the years immediately after diagnosis.

OBJECTIVE

To explore incident infections in MS, stratified by age and sex.

METHODS

In a Swedish population-based cohort study 6602 incident MS patients (aged ≥18 years), matched at diagnosis with 61,828 matched MS-free individuals were identified between 1st January 2008 and 31st December 2016, using national registers. Incidence rates (IR) and incidence rate ratios (IRR) with 95% CI were calculated for each outcome.

RESULTS

The IRRs were 2.54 (95% CI 2.28-2.83) for first serious infection and 1.61 (1.52-1.71) for first non-serious infection. Compared with MS-free individuals, MS patients had higher IRs for skin, respiratory/throat infections, pneumonia/influenza, bacterial, viral, and fungal infections, with the highest IRR observed for urinary tract/kidney infections (2.44; 2.24-2.66). The cumulative incidence for most of these infections was higher among MS patients than MS-free individuals, both 0 to <5 and 5 to <9 years after index date.

CONCLUSION

The burden of infections around the time of MS diagnosis and subsequent infection risk, underscore the need for careful considerations regarding the risk-benefit across different disease-modifying therapies.

A Gene-Environment Interaction Between Smoking and Gene polymorphisms Provides a High Risk of Two Subgroups of Sarcoidosis

The influence and effect of cigarette smoking in sarcoidosis is unclear. Here, we evaluated gene-environment interaction between multiple genetic variants including HLA genes and smoking in sarcoidosis defined by two clinical phenotypes, Löfgren's syndrome (LS) and patients without Löfgren's syndrome (non-LS). To quantify smoking effects in sarcoidosis, we performed a gene-environment interaction study in a Swedish population-based case-control study consisting of 3,713 individuals. Cases and controls were classified according to their cigarette smoking status and genotypes by Immunochip platform. Gene-smoking interactions were quantified by an additive interaction model using a logistic regression adjusted by sex, age and first two principal components. The estimated attributable proportion (AP) was used to quantify the interaction effect. Assessment of smoking effects with inclusion of genetic information revealed 53 (in LS) and 34 (in non-LS) SNP-smoking additive interactions at false discovery rate (FDR) below 5%. The lead signals interacting with smoking were rs12132140 (AP = 0.56, 95% CI = 0.22-0.90), p = 1.28e-03) in FCRL1 for LS and rs61780312 (AP = 0.62, 95% CI = 0.28-0.90), p = 3e-04) in IL23R for non-LS. We further identified 16 genomic loci (in LS) and 13 (in non-LS) that interact with cigarette smoking. These findings suggest that sarcoidosis risk is modulated by smoking due to genetic susceptibility. Therefore, patients having certain gene variants, are at a higher risk for the disease. Consideration of individual's genetic predisposition is crucial to quantify effects of smoking in sarcoidosis.

Risk of Thyroxine-Treated Autoimmune Thyroid Disease Associated With Disease Onset in Patients With Rheumatoid Arthritis

IMPORTANCE

Autoimmune thyroid disease ([AITD] including hypothyroidism and hyperthyroidism) is the most common organ-specific autoimmune disorder and is more prevalent among patients with rheumatoid arthritis (RA). Real-world studies on when and how this increased risk of AITD develops, in association with the time before or after the onset of RA, are lacking.

OBJECTIVE

To estimate the risk of thyroxine-treated AITD among patients with RA at different time points before and after the diagnosis of RA.

DESIGN, SETTING, AND PARTICIPANTS

A nationwide register-based case-control and cohort study was conducted between January 1, 2006, and June 30, 2013, with a maximum follow-up time of 7 years before and 8 years after diagnosis of RA. The study used the Swedish Rheumatology Quality Register and linkage to other nationwide registers to identify 8090 adults with new-onset RA and a random population-based sample of 80 782 referents matched by age, sex, and residential area. Statistical analysis was performed from July 1, 2015, to June 30, 2017.

EXPOSURES

Presence of AITD in the participants in the case-control design and RA in the participants in the cohort design.

MAIN OUTCOMES AND MEASURES

Prevalence and relative risk of incident AITD before (odds ratios) and after (hazard ratios) diagnosis of RA compared with the population as reference.

RESULTS

There were 8090 patients with RA (5529 women and 2561 men; mean [SD] age, 58.3 [15.2] years) and 80 782 population-based participants as reference who were identified. By the time of diagnosis of RA, the prevalence of AITD was 10.3% among the patients with RA (n = 832) vs 7.1% among the controls (5725 of 80 350) (odds ratio, 1.5; 95% CI, 1.4-1.7). This increased risk of AITD developed during the 5 years (range, 2-5 years) before diagnosis of RA (odds ratio, 1.5; 95% CI, 1.2-1.8) and peaked by the time of diagnosis of RA (range, 0-3 months before diagnosis of RA) (odds ratio, 5.3; 95% CI, 3.7-7.6). From diagnosis of RA and onward, the risk of developing AITD decreased (range, 2-5 years after diagnosis of RA) (hazard ratio, 0.7; 95% CI, 0.5-1.0).

CONCLUSIONS AND RELEVANCE

Compared with the general population, Swedish patients with RA appear to have a higher prevalence of thyroxine-treated AITD at diagnosis of RA and an increased incidence of AITD during the 5-year period before diagnosis of RA. After diagnosis of RA, the risk of developing AITD is suggested to decrease below the expected rate. Besides temporal changes in diagnostic intensity, this pattern of risk raises the question whether AITD may influence the pathogenesis of RA (or vice versa) and, conversely, the question whether antirheumatic therapies may prevent AITD.

Sex-specific relevance of diabetes to occlusive vascular and other mortality: a collaborative meta-analysis of individual data from 980 793 adults from 68 prospective studies

BACKGROUND

Several studies have shown that diabetes confers a higher relative risk of vascular mortality among women than among men, but whether this increased relative risk in women exists across age groups and within defined levels of other risk factors is uncertain. We aimed to determine whether differences in established risk factors, such as blood pressure, BMI, smoking, and cholesterol, explain the higher relative risks of vascular mortality among women than among men.

METHODS

In our meta-analysis, we obtained individual participant-level data from studies included in the Prospective Studies Collaboration and the Asia Pacific Cohort Studies Collaboration that had obtained baseline information on age, sex, diabetes, total cholesterol, blood pressure, tobacco use, height, and weight. Data on causes of death were obtained from medical death certificates. We used Cox regression models to assess the relevance of diabetes (any type) to occlusive vascular mortality (ischaemic heart disease, ischaemic stroke, or other atherosclerotic deaths) by age, sex, and other major vascular risk factors, and to assess whether the associations of blood pressure, total cholesterol, and body-mass index (BMI) to occlusive vascular mortality are modified by diabetes.

RESULTS

Individual participant-level data were analysed from 980 793 adults. During 9·8 million person-years of follow-up, among participants aged between 35 and 89 years, 19 686 (25·6%) of 76 965 deaths were attributed to occlusive vascular disease. After controlling for major vascular risk factors, diabetes roughly doubled occlusive vascular mortality risk among men (death rate ratio [RR] 2·10, 95% CI 1·97-2·24) and tripled risk among women (3·00, 2·71-3·33; χ2 test for heterogeneity p<0·0001). For both sexes combined, the occlusive vascular death RRs were higher in younger individuals (aged 35-59 years: 2·60, 2·30-2·94) than in older individuals (aged 70-89 years: 2·01, 1·85-2·19; p=0·0001 for trend across age groups), and, across age groups, the death RRs were higher among women than among men. Therefore, women aged 35-59 years had the highest death RR across all age and sex groups (5·55, 4·15-7·44). However, since underlying confounder-adjusted occlusive vascular mortality rates at any age were higher in men than in women, the adjusted absolute excess occlusive vascular mortality associated with diabetes was similar for men and women. At ages 35-59 years, the excess absolute risk was 0·05% (95% CI 0·03-0·07) per year in women compared with 0·08% (0·05-0·10) per year in men; the corresponding excess at ages 70-89 years was 1·08% (0·84-1·32) per year in women and 0·91% (0·77-1·05) per year in men. Total cholesterol, blood pressure, and BMI each showed continuous log-linear associations with occlusive vascular mortality that were similar among individuals with and without diabetes across both sexes.

INTERPRETATION

Independent of other major vascular risk factors, diabetes substantially increased vascular risk in both men and women. Lifestyle changes to reduce smoking and obesity and use of cost-effective drugs that target major vascular risks (eg, statins and antihypertensive drugs) are important in both men and women with diabetes, but might not reduce the relative excess risk of occlusive vascular disease in women with diabetes, which remains unexplained.

FUNDING

UK Medical Research Council, British Heart Foundation, Cancer Research UK, European Union BIOMED programme, and National Institute on Aging (US National Institutes of Health).

Low levels of antibodies against common viruses associate with anti-citrullinated protein antibody-positive rheumatoid arthritis; implications for disease aetiology

BACKGROUND

Infection by common viruses has long been discussed in the aetiology of a number of autoimmune diseases, including rheumatoid arthritis (RA). However, studies investigating this hypothesis in RA show conflicting results. These studies often lack well-matched control populations, and many do not include data on autoantibodies, genetic risk factors and other environmental factors, which are known to contribute to disease only in subgroups of patients. In the present study, we have therefore examined the role of Epstein-Barr virus (EBV), cytomegalovirus (CMV) and parvovirus B19 (B19) in RA aetiology, by analysing anti-viral antibodies in relation to anti-citrullinated protein antibodies (ACPA), smoking, HLA-DRB1 shared epitope (SE) alleles, and clinical parameters, in both RA patients and matched controls.

METHODS

Anti-viral antibodies were measured by ELISA in serum samples from 990 RA patients and 700 controls from the Swedish population-based Epidemiological Investigation of RA (EIRA) cohort. Data on ACPA, smoking, SE, inflammation (C-reactive protein) and disease activity score in 28 joints (DAS28) was obtained from the EIRA database. Fisher's exact test, the chi-squared test, and the Mann-Whitney U test were used to calculate differences in anti-viral antibody frequencies and levels; unconditional logistic regression was used to determine the association of anti-viral antibodies with different RA subsets.

RESULTS

Antibodies against all viruses were highly prevalent in EIRA, with no major differences detected between ACPA-positive RA, ACPA-negative RA and controls. However, both anti-B19 and anti-EBV IgG levels were significantly lower in ACPA-positive RA compared to controls, and there were significant interactions between low levels of anti-B19 and anti-EBV antibodies and SE in the development of ACPA-positive RA.

CONCLUSION

We could not detect an association between RA and elevated anti-viral antibody levels, for any of the three common viruses, EBV, CMV or B19. On the contrary, our study demonstrated association between low anti-EBV/anti-B19 antibody levels and ACPA-positive RA, in particular when HLA-DRB1 SE was present. These data could potentially suggest that high anti-viral antibody levels would be protective against ACPA-positive RA. Further investigations are required to address the mechanisms behind these findings.

Association Between Menopausal Factors and the Risk of Seronegative and Seropositive Rheumatoid Arthritis: Results From the Nurses' Health Studies

OBJECTIVE

To investigate whether menopausal factors are associated with the development of serologic rheumatoid arthritis (RA) phenotypes.

METHODS

Data were analyzed from the Nurses' Health Studies (NHS; 1976-2010 and NHSII 1989-2011). A total of 120,700 female nurses ages 30-55 years in the NHS, and a total of 116,430 female nurses ages 25-42 years in the NHSII, were followed via biennial questionnaires on lifestyle and disease outcomes. In total, 1,096 incident RA cases were confirmed by questionnaire and chart review. Seropositive RA was defined as rheumatoid factor positive (RF) or antibodies to citrullinated protein antigen (ACPA) positive, and seronegative RA was defined as RF negative and ACPA negative. We used Cox proportional hazards models to obtain multivariable-adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) of seropositive/seronegative RA associated with menopausal status, age at menopause, type of menopause, ovulatory years, and postmenopausal hormone therapy (PMH) use.

RESULTS

Postmenopausal women had a 2-fold increased risk of seronegative RA, compared with premenopausal women (NHS: HR 1.8 [95% CI 1.1-3.0], NHSII: HR 2.4 [95% CI 1.4-3.9], and pooled HR 2.1 [95% CI 1.4-3.0]). Natural menopause at early age (≤44 years) was associated with an increased risk of seronegative RA (pooled HR 2.4 [95% CI 1.5-4.0]). None of the menopausal factors was significantly associated with seropositive RA. We observed no association between PMH use and the risk of seronegative or seropositive RA, except that PMH use of ≥8 years was associated with increased risk of seropositive RA (pooled HR 1.4 [95% CI 1.1-1.9]).

CONCLUSION

Postmenopause and natural menopause at an early age were strongly associated with seronegative RA, but only marginally with seropositive RA, suggesting potential differences in the etiology of RA subtypes.

Oral contraceptives, breastfeeding and the risk of developing rheumatoid arthritis: results from the Swedish EIRA study

OBJECTIVES

To study whether oral contraceptive (OC) use or breastfeeding (BF) influence the risk of rheumatoid arthritis (RA), stratifying the cases by presence/absence of anticitrullinated protein antibodies (ACPA), and whether these factors interact with known risk factors in the development of ACPA-positive RA.

METHODS

Women aged ≥18 years, participants in the population-based case-control Swedish Epidemiological Investigation of RA study (2641 cases/4251 controls), completed an extensive questionnaire regarding OC, BF and potential confounders. We calculated ORs, with 95% CIs, adjusted for age, residential area, smoking and alcohol consumption. Attributable proportion due to interaction (AP) was estimated to evaluate presence of interaction.

RESULTS

Compared with never users, ever and past OC users had a decreased risk of ACPA-positive RA (OR=0.84 (95% CI 0.74 to 0.96); OR=0.83 (95% CI 0.73 to 0.95), respectively). No significant associations were found for ACPA-negative RA. Long duration of OC use (>7 years vs never use) decreased the risk of both ACPA-positive (p=0.0037) and ACPA-negative RA (p=0.0356).A history of long BF decreased the risk only of ACPA-positive RA in a dose-dependent manner (p=0.0086), but this trend did not remain after adjustments. A significant interaction was observed between the lack of OC use and smoking (AP=0.28 (95% CI 0.14-0.42)) on the risk of ACPA-positive RA. No interactions were found for BF.

CONCLUSIONS

OC decreased the risk of RA, especially ACPA-positive RA, where an interaction with smoking was observed. A long duration of OC use decreased the risk of both disease subsets. We could not confirm an association between BF and a decreased risk of either ACPA-positive or ACPA-negative RA.

Working in cold environment and risk of developing rheumatoid arthritis: results from the Swedish EIRA case-control study

Objectives

To investigate (1) whether working in cold environment (WCE) is associated with an increased risk of developing rheumatoid arthritis (RA) (overall), anticitrullinated protein antibody (ACPA)-positive RA and ACPA-negative RA and (2) whether WCE interacts with occupational physical workload in conferring RA risk.

Methods

Data from the Swedish population-based case-control study Epidemiological Investigation of Rheumatoid Arthritis involving 3659 incident cases and 5925 controls were analysed. Study participants were asked whether they had ever worked in cold/outdoor environment along with their exposure duration and frequency. Occurrence of RA among exposed and unexposed subjects were compared by calculating ORs with 95% CI using logistic regression. Additive interactions between WCE and six types of physical workload were assessed using the principle of departure from additivity by calculating attributable proportion due to interaction (AP).

Results

The OR associated with having ever worked in cold environment was 1.5 (95% CI 1.4 to 1.7) for RA (overall), 1.6 (95% CI 1.4 to 1.8) for ACPA-positive RA and 1.4 (95% CI 1.2 to 1.6) for ACPA-negative RA. The risk of developing RA increased with increasing cumulative dose of working in cold indoor environment (p value <0.001), but not working in cold outdoor environment. Positive additive interaction was observed between WCE and repetitive hand/finger movements (AP 0.3 (95% CI 0.1 to 0.5)).

Conclusions

WCE is associated with increased risk of developing both ACPA-positive and ACPA-negative RA. A dose–response relationship was found between working in cold indoor environment and risk of developing RA. Moderate additive interaction was observed between exposure to cold environment and exposure to repetitive hand/finger movements.

Physical workload is associated with increased risk of rheumatoid arthritis: results from a Swedish population-based case-control study

Objectives

This study investigated: (1) the association of physical workload (PW) and risk of rheumatoid arthritis (RA); (2) the potential interactions between PW and the genes in the human leucocyte antigen (HLA) region.

Methods

A population-based case–control study involving incident cases of RA (3150 cases and 5130 controls) was performed using data from the Swedish Epidemiological Investigation of Rheumatoid Arthritis. Information on 7 types of self-reported PW exposure and HLA-DRB1 genotypes of cases and controls were gathered. Anticitrullinated protein antibody (ACPA) status of cases was identified. For each PW exposures, exposed participants were compared with unexposed participants. ORs with 95% CIs of RA (overall), ACPA-positive RA and ACPA-negative RA associated with different PWs were estimated using logistic regression. HLA-PW interactions were estimated using the principle of departure from additivity of effects by calculating attributable proportion (AP) due to interaction.

Results

ORs of developing RA associated with 6 various PW exposures ranging from 1.3 (95% CI 1.1 to 1.4) to 1.8 (95% CI 1.6 to 2.0) were observed. Exposure to more types of PW was associated with increasing risk for RA (p<0.0001). No major difference in the ORs between ACPA-positive and ACPA-negative RA was found. For some exposures, we found evidence of interactions between PW and the HLA-DRB1 shared epitope genes, regarding risk of ACPA-positive RA (AP: from 0.3 (95% CI 0.1 to 0.5) to 0.4 (95% CI 0.2 to 0.6)).

Conclusions

PW is associated with the risk of ACPA-positive and ACPA-negative RA. Interactions between PW and the HLA-DRB1 shared epitope were found in ACPA-positive RA.

Abnormal mechanical properties of larger arteries in postmenopausal women with systemic lupus erythematosus

There is limited knowledge of potential defects in arterial wall properties in female systemic lupus erythematosus (SLE) patients without manifest cardiovascular disease (CVD) and significant atherosclerotic lesions. The aim of the present study was to investigate the mechanical properties of larger vessels in these patients and to compare them with healthy controls. B-mode ultrasound was used to assess vessel wall structure and to exclude presence of plaque. The ankle/brachial pressure index was measured to exclude occlusive arterial disease. An ultrasound echo-tracking system was used to determine stiffness of the abdominal aorta, common carotid artery (CCA) and popliteal artery (PA) in 39 female patientswith SLE and 55 female, healthy controls. SLE had an independent effect on stiffening of the CCA ( P = 0.01) and PA ( P = 0.005). In addition, larger vessel diameters were observed in the CCA (P = 0.002) after adjustments for the effects of mean arterial pressure and age. Thus, this investigation demonstrated an increased arterial stiffness and signs of premature vascular ageing in the SLE patients without manifest cardiovascular disease and without significant atherosclerotic lesions. The results of this study indicate that other mechanisms besides atherosclerosis might be involved in the pathogenesis of arterial stiffening in SLE patients.

Increased aortic pulse wave velocity in middle aged women with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a connective tissue disease where inflammatory activity affects several organ systems. An increased risk of cardiovascular disease has been identified in these patients, even after correction for traditional risk factors. The aim of the present study was to evaluate arterial stiffness and central hemodynamics in women with SLE in comparison to controls.

Arterial tonometry was used to measure aortic (carotid-femoral) and arm (carotid-radial) pulse wave velocity (PWV), reflected pressure waves, and aortic augmentation index (AIx) in 27 women with SLE (52 to 68 years) and 27 controls. Aortic PWV was higher in women with SLE than controls, 9.8 m/s versus 8.2 m/s ( P 0.01), after correction for mean arterial pressure and body mass index, 9.5 m/s versus 8.5 m/s ( P 0.05). Other parameters were similar, arm PWV, 8.4 versus 8.5 m/s, AIx 34 versus 33% and calculated central aortic pulse pressure 48 versus 43 mmHg, in SLE and controls, respectively (NS). Aortic PWV was positively associated to C-reactive protein (CRP) and complement factor 3 (C3).

Women with SLE have increased stiffness of their elastic central arteries. This may be one factor contributing to the increased cardiovascular risk seen in this cohort.

Occupational exposure to textile dust increases the risk of rheumatoid arthritis: results from a Malaysian population-based case-control study

Objectives

Lung exposures including cigarette smoking and silica exposure are associated with the risk of rheumatoid arthritis (RA). We investigated the association between textile dust exposure and the risk of RA in the Malaysian population, with a focus on women who rarely smoke.

Methods

Data from the Malaysian Epidemiological Investigation of Rheumatoid Arthritis population-based case–control study involving 910 female early RA cases and 910 female age-matched controls were analysed. Self-reported information on ever/never occupationally exposed to textile dust was used to estimate the risk of developing anti-citrullinated protein antibody (ACPA)-positive and ACPA-negative RA. Interaction between textile dust and the human leucocyte antigen DR β-1 (HLA-DRB1) shared epitope (SE) was evaluated by calculating the attributable proportion due to interaction (AP), with 95% CI.

Results

Occupational exposure to textile dust was significantly associated with an increased risk of developing RA in the Malaysian female population (OR 2.8, 95% CI 1.6 to 5.2). The association between occupational exposure to textile dust and risk of RA was uniformly observed for the ACPA-positive RA (OR 2.5, 95% CI 1.3 to 4.8) and ACPA-negative RA (OR 3.5, 95% CI 1.7 to 7.0) subsets, respectively. We observed a significant interaction between exposure to occupational textile dust and HLA-DRB1 SE alleles regarding the risk of ACPA-positive RA (OR for double exposed: 39.1, 95% CI 5.1 to 297.5; AP: 0.8, 95% CI 0.5 to 1.2).

Conclusions

This is the first study demonstrating that textile dust exposure is associated with an increased risk for RA. In addition, a gene–environment interaction between HLA-DRB1 SE and textile dust exposure provides a high risk for ACPA-positive RA.

Parity influences the severity of ACPA-negative early rheumatoid arthritis: a cohort study based on the Swedish EIRA material

BACKGROUND

In women with rheumatoid arthritis (RA) it has been observed that during pregnancy a majority of patients experience amelioration, but after delivery a relapse of the disease is common. However, there are few studies, with diverging results, addressing the effect of parity on the severity of RA over time. Our aim was to explore the impact of parity, with stratification for anti-citrullinated protein antibody (ACPA) status as well as for onset during reproductive age or not.

METHODS

Female RA cases aged 18-70 years were recruited for the Epidemiological Investigation of Rheumatoid Arthritis (EIRA). Information on disease severity (the health assessment questionnaire (HAQ) and the disease activity score 28 (DAS28)) was retrieved from the Swedish Rheumatology Quality Register at inclusion and 3, 6, 12 and 24 months after diagnosis. Mixed models were used to compare mean DAS28 and HAQ scores over time in parous and nulliparous women. Mean differences at individual follow-up visits were compared using analysis of covariance. The odds of having DAS28 or HAQ above the median in parous verus nulliparous women were estimated in logistic regression models.

RESULTS

A total of 1237 female cases (mean age 51 years, 65 % ACPA-positive) were included. ACPA-negative parous women, aged 18-44 years, had on average 1.17 units higher DAS28 (p < 0.001) and 0.43 units higher HAQ score (p < 0.001) compared to nulliparous women during the follow-up time, adjusted for age. In this subgroup, the average DAS28 and HAQ scores were significantly higher in parous women at all follow-up time points. Younger parous ACPA-negative women were significantly more likely to have DAS28 and HAQ values above the median compared to nulliparous women at all follow-up visits. No association between parity and severity of ACPA-positive disease was observed.

CONCLUSIONS

Parity was a predictor of a more severe RA among ACPA-negative younger women, which might indicate that immunomodulatory changes during and after pregnancy affect RA severity, in particular for the ACPA-negative RA phenotype.

Higher education is associated with a better rheumatoid arthritis outcome concerning for pain and function but not disease activity: results from the EIRA cohort and Swedish rheumatology register

Introduction

Whether low socioeconomic status (SES) is associated with worse rheumatoid arthritis (RA) outcomes in countries with general tax-financed healthcare systems (such as Sweden) remains to be elucidated. Our aim was to investigate the influence of educational background (achieving university/college degree (high) or not (low)) on the outcomes of early RA, in terms of disease activity (DAS28), pain (VAS-pain), and functional impairment (HAQ).

Methods

We evaluated DMARD-naïve RA patients recruited in the Epidemiological Investigation of RA (EIRA) study with outcomes followed in the Swedish Rheumatology Quality (SRQ) register (N = 3021). Outcomes were categorized in three ways: 1) scores equal to/above median vs. below median; 2) DAS28-based low disease activity, good response, remission; 3) scores decreased over the median vs. less than median. Associations between educational background and outcomes were calculated by modified Poisson regressions, at diagnosis and at each of the three standard (3, 6, 12 months) follow-up visits.

Results

Patients with different educational background had similar symptom durations (195 days) and anti-rheumatic therapies at baseline, and comparable treatment patterns during follow-up. Patients with a high education level had significantly less pain and less functional disability at baseline and throughout the whole follow-up period (VAS-pain: baseline: 49 (28-67) vs. 53 (33-71), p <0.0001; 1-year visit: RR = 0.81 (95 % CI 0.73-0.90). HAQ: baseline: 0.88 (0.50-1.38) vs. 1.00 (0.63-1.50), p = 0.001; 1-year visit: 0.84 (0.77-0.92)). They also had greater chances to achieve pain remission (VAS-pain ≤20) after one year (1.17 (1.07-1.28)). Adjustments for smoking and BMI altered the results only marginally. Educational background did not influence DAS28-based outcomes.

Conclusion

In Sweden, with tax-financed, generally accessible healthcare system, RA patients with a high education level experienced less pain and less functional disability. Further, these patients achieved pain remission more often during the first year receiving standard care. Importantly, education background affected neither time to referral to rheumatologists, disease activity nor anti-rheumatic treatments.

Associations with smoking and shared epitope differ between IgA- and IgG-class antibodies to cyclic citrullinated peptides in early rheumatoid arthritis

OBJECTIVE

Smoking and HLA-DRB1/shared epitope (SE) alleles are risk factors for rheumatoid arthritis (RA) characterized by seropositivity for antibodies targeting citrullinated proteins (ACPAs)/cyclic citrullinated peptides (anti-CCP). Previously, mainly IgG-class antibodies have been studied. IgA-class antibodies are to a great extent related to mucosal immunity. The aim of this study was to explore interrelations between cigarette smoking, presence of SE, and seropositivity for circulating IgA and/or IgG anti-CCP antibodies among patients with early RA, to determine whether ACPAs of the IgA subclass are regulated by different mechanisms than those of the IgG subclass.

METHODS

Two cohorts of patients with early RA, from the first Epidemiological Investigations of RA trial (n = 1,663) and the second Early Intervention in RA trial (n = 199), were grouped into 4 subsets based on anti-CCP subclass status (IgG-/IgA-, IgG-/IgA+, IgG+/IgA-, and IgG+/IgA+), and each subset was compared with regard to associations with smoking (current and former) and presence of SE. Interaction between smoking and SE was calculated using the attributable proportion (AP) due to interaction (assessing deviation from additivity of effects).

RESULTS

Smoking was overrepresented among IgA anti-CCP-positive RA patients, regardless of whether IgG anti-CCP were present, whereas in patients with IgG anti-CCP alone, no association with smoking was found. SE alleles were overrepresented among IgG anti-CCP-positive patients, regardless of IgA anti-CCP status, and was not seen in patients with IgA anti-CCP alone. An interaction between ever smoking and SE was found with regard to the risk of IgG+/IgA+ RA (AP 0.5, 95% confidence interval 0.4, 0.6). No significant interaction was observed with regard to the risk of IgG-/IgA+ RA or IgG+/IgA- RA.

CONCLUSION

In patients with RA, a history of ever smoking was associated with seropositivity for IgA anti-CCP antibodies, whereas presence of SE was associated with seropositivity for IgG anti-CCP antibodies. An interaction between ever smoking and the SE was limited to the RA subset characterized by seropositivity for both IgG and IgA anti-CCP. These findings provide novel evidence that anti-CCP-positive RA can be divided into at least 3 serologically distinct subsets associated with different risk factors, indicating different modes of pathogenesis in RA.

Silica exposure is associated with an increased risk of developing ACPA-positive rheumatoid arthritis in an Asian population: evidence from the Malaysian MyEIRA case-control study

OBJECTIVES

Silica exposure has been associated with an increased risk of developing rheumatoid arthritis (RA), especially among smokers. In this study, we aimed at examining the association between silica exposure (and its interaction with smoking) and the risk of RA in the Malaysian population.

METHODS

In total, 149 cases and 213 matched controls, all men, were included between August 2005 and December 2009. A case was defined as a person with early diagnosed RA using the 1987 American College of Rheumatology criteria for RA. Controls were randomly selected matched on sex, age and residential area. Silica exposure was defined as exposure to stone dust, rock drilling or stone crushing, and smoking status was categorized as ever/never cigarette smoking.

RESULTS

An increased risk of anti-citrullinated protein antibody (ACPA)-positive RA (OR = 2.4, 95 % CI 1.0-5.6) was observed among those exposed to silica. Ever-smokers exposed to silica had a particularly high risk of developing ACPA-positive RA (OR = 7.5, 95 % CI 2.3-24.2), compared with never-smokers not exposed to silica. No association was found regarding ACPA-negative RA.

CONCLUSION

Our data demonstrate that exposure to both silica and cigarette smoke comprise risks for developing RA in the Malaysian genetic context. The findings expand a link between environmental lung exposures and ACPA-positive RA to Asian populations.