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Karp, Kjell
Publications (10 of 21) Show all publications
Erelund, S., Karp, K., Arvidsson, S., Johansson, B., Sundström, N. & Wiklund, U. (2023). Pulmonary function in a cohort of heart-healthy individuals from Northern Sweden: a comparison with discordant reference values. BMC Pulmonary Medicine, 23(1), Article ID 110.
Open this publication in new window or tab >>Pulmonary function in a cohort of heart-healthy individuals from Northern Sweden: a comparison with discordant reference values
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2023 (English)In: BMC Pulmonary Medicine, E-ISSN 1471-2466, Vol. 23, no 1, article id 110Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Dynamic spirometry is an important investigation to differentiate between impaired and normal lung function. This study aimed to evaluate the results of lung function testing in a cohort of subjects from Northern Sweden without any known heart or pulmonary disease. Our focus was to compare with two reference materials that have showed differences in the age-dependency of lung function in Swedish subjects.

METHODS: The study population consisted of 285 healthy adults (148 males, 52%) between 20-90 years of age. The subjects had been randomly selected from the population register for inclusion in a study investigating cardiac function in heart-healthy subjects, but were also assessed with dynamic spirometry. At least seven percent reported smoking. Sixteen subjects presented with pulmonary functional impairments and were excluded from the current study. The sex-specific age-dependency in lung volumes was estimated using the LMS model, where non-linear equations were derived for the mean value (M), the location (L) or skewness, and the scatter (S) or coefficient of variation. This model of the observed lung function data was compared with reference values given by the original LMS model published by the Global Lung Initiative (GLI), and with the model from the recent Obstructive Lung Disease In Norrbotten (OLIN) study, where higher reference values were presented for Swedish subjects than those given by the GLI model.

RESULTS: No differences were found in the age-dependency of pulmonary function between the LMS model developed in the study and the OLIN model. Although the study group included smokers, the original GLI reference values suggested significantly lower normal values of FEV1 (forced expiratory volume) and FVC (forced vital capacity), and consequently fewer subjects below the lower limit of normality, than both the rederived LMS and OLIN models.

CONCLUSIONS: Our results are in line with previous reports and support that the original GLI reference values underestimate pulmonary function in the adult Swedish population. This underestimation could be reduced by updating the coefficients in the underlying LMS model based on a larger cohort of Swedish citizens than was available in this study.

Place, publisher, year, edition, pages
BioMed Central (BMC), 2023
Keywords
Clinical physiology, Linear regression, Lung function, Reference values, Spirometry
National Category
Respiratory Medicine and Allergy
Identifiers
urn:nbn:se:umu:diva-206770 (URN)10.1186/s12890-023-02403-w (DOI)000963360400001 ()37020237 (PubMedID)2-s2.0-85151789612 (Scopus ID)
Available from: 2023-04-26 Created: 2023-04-26 Last updated: 2024-01-17Bibliographically approved
Erelund, S., Karp, K., Wiklund, U., Hörnsten, R. & Arvidsson, S. (2021). Are ECG changes in heart-healthy individuals of various ages related to cardiac disease 20 years later?. Upsala Journal of Medical Sciences, 126(1), Article ID e6064.
Open this publication in new window or tab >>Are ECG changes in heart-healthy individuals of various ages related to cardiac disease 20 years later?
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2021 (English)In: Upsala Journal of Medical Sciences, ISSN 0300-9734, E-ISSN 2000-1967, Vol. 126, no 1, article id e6064Article in journal (Refereed) Published
Abstract [en]

Background: This research study aimed at assessing the electrocardiographic (ECG) changes caused by ageing in a cohort of healthy subjects with normal echocardiographic examinations.

Methods: A total of 219 healthy individuals (119 males and 100 females) were evaluated for possible arrhythmias with a standard 12-lead resting ECG and 24-h Holter ECG. As the recordings were performed between 1998 and 2000, a 20-year follow-up study was carried out by assessing the local medical records to investigate whether the subjects had experienced any cardiovascular health complications or disease since the baseline assessment.

Results: Eighty-three subjects (45 males and 38 females) presented with pathological ECG findings at baseline. The most common finding on analysis of Holter ECG recordings was premature atrial contractions, and the most severe pathological finding was episodes of ventricular tachycardia (eight subjects). Regarding the analysis of the standard 12-lead ECG, the most common finding was left ventricular hypertrophy, and the most severe pathological findings were ST-T changes and prolongation of the QT interval. Despite other cardiac examinations performed on these patients showing normal results, in combination with a strict inclusion criterion, this study showed that 28% of all subjects had pathological resting 12-lead ECGs at rest and 35% had pathological heart rhythms when assessed by 24-h Holter ECG. At follow-up, 21% of females and 43% of males had presented with ECG abnormalities, and 30% of females and 36% of males had cardiovascular disease. There was hypertension in 45% of females and in 58% of males. However, no association was found between the follow-up findings and ECG changes seen at baseline.

Conclusion: Although most ECG changes found at baseline could be considered as a normal variation, they may progress to more severe heart complications as the subject ages. The results of this study also validate ECG findings of previous studies and underline that diagnostic criteria should be based on gender and age.

Place, publisher, year, edition, pages
Upsala Medical Society, 2021
Keywords
Arrhythmia, Clinical physiology, Electrocardiogram, Heart function test, Normal values
National Category
Cardiology and Cardiovascular Disease
Identifiers
urn:nbn:se:umu:diva-186419 (URN)10.48101/ujms.v126.6064 (DOI)000683141300001 ()2-s2.0-85110436769 (Scopus ID)
Funder
Region Västerbotten
Available from: 2021-07-29 Created: 2021-07-29 Last updated: 2025-02-10Bibliographically approved
Wahlin, B., Fasth, A., Karp, K., Lejon, K., Malmström, V., Rahbar, A., . . . Södergren, A. (2021). Atherosclerosis in rheumatoid arthritis: associations between anti-cytomegalovirus IgG antibodies, CD4+CD28null T-cells, CD8+CD28null T-cells and intima-media thickness. Clinical and Experimental Rheumatology, 39(3), 578-586
Open this publication in new window or tab >>Atherosclerosis in rheumatoid arthritis: associations between anti-cytomegalovirus IgG antibodies, CD4+CD28null T-cells, CD8+CD28null T-cells and intima-media thickness
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2021 (English)In: Clinical and Experimental Rheumatology, ISSN 0392-856X, E-ISSN 1593-098X, Vol. 39, no 3, p. 578-586Article in journal (Refereed) Published
Abstract [en]

Objectives: Patients with rheumatoid arthritis (RA) have an accelerated progression of atherosclerosis. The aims of this study were to study the associations between subsets of T-cells, subclinical atherosclerosis assessed by intima-media thickness (IMT) and serological status for CMV in patients with RA.

Methods: Patients with new-onset RA (n=79), aged ≤60 years at diagnosis, were included in a prospective study of atherosclerosis. Controls matched for age and sex were also included (n=44). Ultrasound measurement of IMT in the common carotid artery was undertaken at inclusion (T0), after 1.5 years (T1.5) and after 11 years (T11). At T11, flow-cytometry analysis was undertaken to investigate subsets of T-cells. Serological analysis for CMV was undertaken from samples collected at T0.

Results: At T0, 66% of the patients and controls were CMV immunoglobulin G-positive. CMV-IgG positive patients had a significantly more rapid increase in IMT at T1.5, compared with controls and CMV-IgG negative patients. CMV-IgG positive patients had a significantly higher percentage of T-cells lacking CD28 (both CD4+CD28null and CD8+CD28null T-cells) than CMV-IgG negative patients. Increased levels of CD4+CD28null and CD8+CD28null T-cells were significantly associated with IMT at T11, adjusted for systolic blood pressure. CX3CR1 was expressed in CD4+ and CD8+ CD28null T-cells, but CX3CR1 per se was not associated with increased IMT.

Conclusions: Presence of CMV IgG-antibodies in patients with RA is associated with altered T-cell-populations and an increased burden of atherosclerosis. A possible protective effect of antiviral treatment in CMV-positive patients with new-onset RA should be considered.

Place, publisher, year, edition, pages
Clinical and Experimental Rheumatology S.A.S., 2021
Keywords
rheumatoid arthritis, atherosclerosis, T-cells, CD28, cytomegalovirus
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-158135 (URN)10.55563/clinexprheumatol/gs3o43 (DOI)32896254 (PubMedID)2-s2.0-85106505647 (Scopus ID)
Funder
Region VästerbottenStiftelsen Konung Gustaf V:s 80-årsfondSwedish Rheumatism Association
Note

Previously included in thesis in manuscript form. 

Available from: 2019-04-12 Created: 2019-04-12 Last updated: 2025-02-18Bibliographically approved
Södergren, A., Karp, K., Bengtsson, C., Möller, B., Rantapää-Dahlqvist, S. & Wållberg-Jonsson, S. (2019). Biomarkers associated with cardiovascular disease in patients with early rheumatoid arthritis. PLOS ONE, 14(8), Article ID e0220531.
Open this publication in new window or tab >>Biomarkers associated with cardiovascular disease in patients with early rheumatoid arthritis
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2019 (English)In: PLOS ONE, E-ISSN 1932-6203, Vol. 14, no 8, article id e0220531Article in journal (Refereed) Published
Abstract [en]

Objectives: Patients with rheumatoid arthritis (RA) have an increased mortality and morbidity due to cardiovascular disease (CVD). In this prospective 5-year follow up of patients with RA, we analysed several biomarkers, known to be associated with atherosclerosis and/or inflammation in the general population. The aim of this study was to find out whether the RA-disease per se affect these biomarkers and if those could be associated with the progression of atherosclerosis, as measured by intima media thickness (IMT) among patients with early RA.

Methods: Patients from northern Sweden diagnosed with early RA, are consecutively recruited into an ongoing prospective study on CVD comorbidity. A subgroup of patients, aged ≤60 years (n = 71) was included for ultrasound measurements of IMT at inclusion (T0) and after 5 years (T5) together with age-sex-matched controls (n = 40). The patients were clinically assessed. Blood was analysed for lipids, ESR and CRP and several biomarkers known to be associated with atherosclerosis in the general population.

Results: At T0, the patients with RA had significantly lower levels of MIF and significantly higher levels of interleukin (IL)-18 and MIC-1 compared with controls. At T5, the patients with RA had significantly higher levels of pentraxin3, MIC-1, TNF-R2, ICAM-1, VCAM-1 and endostatin compared with controls. At T0 the levels of MPO correlated with DAS28, sCD40L with CRP and IL-18 with systolic blood pressure and Reynolds risk score. Using PLSR on a CVD-panel analysed with multiplex immunoassay, the patients with RA could be correctly classified into those who had a worsening in their IMT over the five years or not. Here, MMP3 was identified as influential.

Conclusions: This study indicates that the RA disease itself could affect several of the biomarkers in this study, and possibly also the processes involved in the development of atherosclerosis.

Place, publisher, year, edition, pages
Public Library of Science, 2019
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-164650 (URN)10.1371/journal.pone.0220531 (DOI)000484993600022 ()31381601 (PubMedID)2-s2.0-85070281863 (Scopus ID)
Available from: 2019-10-25 Created: 2019-10-25 Last updated: 2025-02-18Bibliographically approved
Wahlin, B., Fasth, A. E., Karp, K., Lejon, K., Södergren, A. & Wållberg-Jonsson, S. (2017). Cd8+cd28- t-lymphocytes are associated with subclinical atherosclerosis in patients with rheumatoid arthritis. Paper presented at Annual European Congress of Rheumatology, JUN 14-17, 2017, Madrid, SPAIN. Annals of the Rheumatic Diseases, 76, 250-250
Open this publication in new window or tab >>Cd8+cd28- t-lymphocytes are associated with subclinical atherosclerosis in patients with rheumatoid arthritis
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2017 (English)In: Annals of the Rheumatic Diseases, ISSN 0003-4967, E-ISSN 1468-2060, Vol. 76, p. 250-250Article in journal, Meeting abstract (Other academic) Published
Place, publisher, year, edition, pages
BMJ PUBLISHING GROUP, 2017
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-142290 (URN)10.1136/annrheumdis-2017-eular.4364 (DOI)000413181400665 ()
Conference
Annual European Congress of Rheumatology, JUN 14-17, 2017, Madrid, SPAIN
Available from: 2017-11-29 Created: 2017-11-29 Last updated: 2025-02-18Bibliographically approved
Hagström, L., Henein, M. Y., Karp, K., Waldenström, A. & Lindqvist, P. (2017). Impact of age and sex on normal left heart structure and function. Clinical Physiology and Functional Imaging, 37(6), 759-766
Open this publication in new window or tab >>Impact of age and sex on normal left heart structure and function
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2017 (English)In: Clinical Physiology and Functional Imaging, ISSN 1475-0961, E-ISSN 1475-097X, Vol. 37, no 6, p. 759-766Article in journal (Refereed) Published
Abstract [en]

BACKGROUND: Accurate age- and sex-related normal reference values of ventricular structure and function are important to determine the level of dysfunction in patients. The aim of this study therefore was to document normal age range sex-related measurements of LV structural and functional measurements to serve such purpose.

METHODS: We evaluated left ventricular structure and function in 293 healthy subjects between 20 and 90 years with equally distributed gender. Doppler echocardiography was used including measure of both systolic and diastolic functions.

RESULTS: Due to systolic LV function, only long axis function correlated with age (r = 0·55, P<0·01) and the correlation was stronger in females. Concerning diastolic function, there was a strong age correlation in all parameters used (r = 0·40-0·74, P<0·001). Due to LV structural changes over age, females showed a larger reduction in end-diastolic volumes, but no or trivial difference in wall thickness after the age of 60 years.

CONCLUSION: Age is associated with significant normal changes in left ventricular structure and function, which should be considered when deciding on normality. These changes are related to systemic arterial changes as well as body stature, thus reflecting overall body ageing process. Furthermore, normal cardiac ageing in females might partly explain the higher prevalence of heart failure with preserved ejection in females.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
age, cardiac function, sex
National Category
Cardiology and Cardiovascular Disease Physiology and Anatomy
Identifiers
urn:nbn:se:umu:diva-122375 (URN)10.1111/cpf.12371 (DOI)000413678400030 ()27283123 (PubMedID)2-s2.0-84976871519 (Scopus ID)
Available from: 2016-06-16 Created: 2016-06-16 Last updated: 2025-02-10Bibliographically approved
Leijon-Sundqvist, K., Tegner, Y., Olsson, F., Karp, K. & Lehto, N. (2017). Relation between dorsal and palmar hand skin temperatures during a cold stress test. Journal of Thermal Biology, 66, 87-92
Open this publication in new window or tab >>Relation between dorsal and palmar hand skin temperatures during a cold stress test
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2017 (English)In: Journal of Thermal Biology, ISSN 0306-4565, E-ISSN 1879-0992, Vol. 66, p. 87-92Article in journal (Refereed) Published
Abstract [en]

Hand skin temperature measurements have previously been performed on either dorsal or palmar sides and it is possible to find arguments for the advantage of both locations. Therefore, the aim of this study was to use dynamic infrared (IR) imaging to examine the relationship between dorsal and palmar hand skin temperature. The palmar and dorsal hand skin temperature before and after a cold stress test was measured with IR thermography in 112 healthy participants. Calculation of surface average temperature was made from nine regions of interest on each hand's dorsal and palmar side. Temperature values were recorded at baseline, directly after immersion of hands in vinyl gloves for one minute in water at 20 +/- 0.5 degrees C (gloves removed), and after eight minutes rewarming. Results showed that: a) the skin temperatures on the dorsal and palmar sides of the hand are strongly correlated; b) the correlation is stronger on the fingers than on the carpometacarpal (CMC) area; c) the palmar side of the CMC area is warmer than the dorsal side, but this is reversed in the fingers so that the nail bed is warmer than the finger pad; and d) the temperature difference Delta T between the dorsal and palmar sides of the fingers is independent of the skin temperature, though Delta T on the CMC area of the hand is temperature dependent. Such differences can be important in detailed investigations of thermal phenomena in the hand. In conclusion, results showed a strong correlation between the dorsal and palmar temperatures. If both sides cannot be measured, the purpose of the investigation should determine which side of the hand should be measured.

Keywords
Opisthenar, Volar, CST, Vascular response, Peripheral circulation, Thermoregulation
National Category
Philosophy
Identifiers
urn:nbn:se:umu:diva-136339 (URN)10.1016/j.jtherbio.2017.04.003 (DOI)000401388300012 ()28477914 (PubMedID)2-s2.0-85017527831 (Scopus ID)
Available from: 2017-06-19 Created: 2017-06-19 Last updated: 2023-03-24Bibliographically approved
Leijon-Sundqvist, K., Tegner, Y., Juntti, U., Karp, K. & Lehto, N. (2016). Hand skin temperature - Are there warm and cold rewarming patterns after cold stress test?. Thermology International, 26(3), 81-87
Open this publication in new window or tab >>Hand skin temperature - Are there warm and cold rewarming patterns after cold stress test?
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2016 (English)In: Thermology International, ISSN 1560-604X, Vol. 26, no 3, p. 81-87Article in journal (Refereed) Published
Abstract [en]

In 116 thermographic measurements of 66 healthy male participants, 44 of whom were measured at least twice, hand skin temperature distributions before and after a cold stress test (CST) were examined to identify any typical characteristics of hand skin rewarming. On each hand, measurements from 18 regions of interest recorded every 10 s were used to calculate the surface average temperature. Temperatures at baseline (Tb), directly after cooling (Tc), and after 15 min of rewarming (Tf) were used for comparison and the averages of each finger, palm, and hand were analyzed. Using fits of normal distribution for the measured data, final hand skin temperatures were divided into two groups, A and B, with a calculated boundary at 25.4 °C. Digital analyses of all thermograms were performed to describe the process, and each group's rewarming patterns were observed. Group A was considered to demonstrate warm rewarming, since the whole hands reached a Tf approximately equal to the Tb. By contrast, Group B demonstrated cold rewarming and had whole hand Tf less than Tb. The predictive value of Tc was lower than that of Tb in Group A, whereas the opposite occurred in Group B. Altogether, the findings suggest different hand skin temperature rewarming patterns in healthy males.

Place, publisher, year, edition, pages
Ludwig Boltzmann Forsch. fur Physikalishe Diagnostik, 2016
Keywords
Cold hands, Cold stress test, Peripheral circulation, Vascular response, Warm hands
National Category
Surgery Physiology and Anatomy
Identifiers
urn:nbn:se:umu:diva-200036 (URN)2-s2.0-85005987231 (Scopus ID)
Available from: 2022-10-07 Created: 2022-10-07 Last updated: 2025-02-10Bibliographically approved
Södergren, A., Karp, K., Bengtsson, C., Möller, B., Rantapää-Dahlqvist, S. & Wållberg-Jonsson, S. (2015). Is Lipoprotein-Associated Phospholipase A2a Link between Inflammation and Subclinical Atherosclerosis inRheumatoid Arthritis?. BioMed Research International, Article ID 673018.
Open this publication in new window or tab >>Is Lipoprotein-Associated Phospholipase A2a Link between Inflammation and Subclinical Atherosclerosis inRheumatoid Arthritis?
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2015 (English)In: BioMed Research International, ISSN 2314-6133, E-ISSN 2314-6141, article id 673018Article in journal (Refereed) Published
Abstract [en]

Objective. Lipoprotein-associated phospholipase A2 (Lp-PLA2), a marker of vascular inflammation, is associated with cardiovascular disease. This prospective study of an inception cohort aimed to investigate whether the level of Lp-PLA2 is associated with subclinical atherosclerosis in patients with rheumatoid arthritis (RA). Methods. Patients from northern Sweden diagnosed with early RA were consecutively recruited into an ongoing prospective study. From these, all patients <= 60 years (n = 71) were included for measurements of subclinical atherosclerosis at inclusion (T0) and five years later (T5). Forty age-and sex-matched controls were included. The patients were clinically assessed, SCORE, Reynolds Risk Score, and Larsen score were calculated, and blood samples were drawn from all individuals at T0 and T5. Results. There was no significant difference in the level of Lp-PLA2 between patients with RA and controls (p > 0.05). In simple linear regression models among patients with RA, Lp-PLA2 at T0 was significantly associated with intima media thickness (IMT) at T0 and T5, flow mediated dilation (FMD) at T0 and T5, ever smoking, male sex, HDL-cholesterol (inversely), non-HDL-cholesterol, SCORE, Reynolds Risk Score, and Larsen score (p < 0.05). Conclusion. In this cohort of patients with early RA, the concentration of Lp-PLA2 was associated with both subclinical atherosclerosis and disease severity.

Place, publisher, year, edition, pages
Hindawi Publishing Corporation, 2015
Keywords
phospholipase, cardiovascular disease, Lp-PLA2
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-111521 (URN)10.1155/2015/673018 (DOI)000363154200001 ()26504820 (PubMedID)2-s2.0-84945280925 (Scopus ID)
Available from: 2015-12-03 Created: 2015-11-13 Last updated: 2025-02-18Bibliographically approved
Södergren, A., Karp, K., Bengtsson, C., Moller, B., Rantapää-Dahlqvist, S. & Wållberg-Jonsson, S. (2015). The Extent of Subclinical Atherosclerosis Is Partially Predicted by the Inflammatory Load: A Prospective Study over 5 Years in Patients with Rheumatoid Arthritis and Matched Controls. Journal of Rheumatology, 42(6), 935-942
Open this publication in new window or tab >>The Extent of Subclinical Atherosclerosis Is Partially Predicted by the Inflammatory Load: A Prospective Study over 5 Years in Patients with Rheumatoid Arthritis and Matched Controls
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2015 (English)In: Journal of Rheumatology, ISSN 0315-162X, E-ISSN 1499-2752, Vol. 42, no 6, p. 935-942Article in journal (Refereed) Published
Abstract [en]

Objective. This prospective followup study investigated subclinical atherosclerosis in relation to traditional cardiovascular disease (CVD) risk factors and inflammation in patients with rheumatoid arthritis (RA) recruited at diagnosis compared with controls. Methods. Patients diagnosed with early RA were consecutively recruited into a prospective study. From these, a subgroup aged <= 60 years (n = 71) was consecutively included for ultrasound measurement of intima-media thickness (IMT) and flow-mediated dilation (FMD) at inclusion (T0) and after 5 years (T5). Age-and sex-matched controls (n = 40) were also included. Results. In the Wilcoxon signed-rank test, both IMT and FMD were significantly aggravated at T5 compared to baseline in patients with RA, whereas only IMT was significantly increased in controls. In univariate linear regression analyses among patients with RA, the IMT at T5 was significantly associated with age, systolic blood pressure (BP), cholesterol, triglycerides, Systematic Coronary Risk Evaluation (SCORE), and Reynolds Risk Score at baseline (p < 0.05). Similarly, FMD at T5 was significantly inversely associated with age, smoking, systolic BP, SCORE, and Reynolds Risk Score (p < 0.05). A model with standardized predictive value from multiple linear regression models including age, smoking, BP, and blood lipids at baseline significantly predicted the observed value of IMT after 5 years. When also including the area under the curve for the 28-joint Disease Activity Score over 5 years, the observed value of IMT was predicted to a large extent. Conclusion. This prospective study identified an increased subclinical atherosclerosis in patients with RA. In the patients with RA, several traditional CVD risk factors at baseline significantly predicted the extent of subclinical atherosclerosis 5 years later. The inflammatory load over time augmented this prediction.

Keywords
Rheumatoid Arthritis, Cardiovascular Disease, Inflammation, Atherosclerosis, Prospective
National Category
Clinical Medicine
Identifiers
urn:nbn:se:umu:diva-106500 (URN)10.3899/jrheum.140694 (DOI)000355543300006 ()25877503 (PubMedID)2-s2.0-84940518088 (Scopus ID)
Available from: 2015-07-16 Created: 2015-07-14 Last updated: 2025-02-18Bibliographically approved
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