title: Co-morbidity in patients with early rheumatoid arthritis - inflammation matters.
abstract: BACKGROUND
  Patients with rheumatoid arthritis (RA) suffer from co-morbidities that contribute to a shortened lifespan. Inflammation is important for the development of cardiovascular disease, but little is known on its relationship with other co-morbidities. We investigated the role of inflammation for the development of new comorbidities in early RA.
  
  
  METHODS
  Since 1995, all patients with early RA in Northern Sweden are included in a prospective study on co-morbidities, with a total of 950 patients being included. At the time for this study, 726 had been ill for ≥5 years. Data on co-morbidities, clinical and laboratory disease activity and pharmacological therapy were collected from patient records and further validated using a questionnaire at RA onset (T0) and after 5 years (T5).
  
  
  RESULTS
  Of the patients, 53.2 % of the patients had one or more co-morbidity at onset, the commonest being: hypertension (27.3 %), obstructive pulmonary disease (13.9 %), diabetes (8.0 %), hypothyroidism (6.3 %) and malignancy (5.0 %). After 5 years, 41.0 % had developed at least one new co-morbidity, the most common being: hypertension (15.1 %), malignancy (7.6 %), stroke/transient ischemic accident (5.1 %), myocardial infarction (4.3 %) and osteoporosis (3.7 %). Age at disease onset, a raised erythrocyte sedimentation rate (ESR) at inclusion, previous treatment with glucocorticoids (GC; p < 0.001 for all), extra-articular RA (Ex-RA; p < 0.01), DAS28 (area under the curve) at 24 months (p < 0.05), previous smoking at inclusion (p = 0.058) and male gender (p < 0.01) were associated with a new co-morbidity overall at T5. Treatment with biologics (p < 0.05) reduced the risk. In multiple logistic regression modelling, ESR (p = 0.036) at inclusion was associated with a new co-morbidity after 5 years, adjusted for age, sex, smoking and GC treatment. In a similar model, Ex-RA (p < 0.05) was associated with a new co-morbidity at T5. In a third model, adjusted for age and sex, a new pulmonary co-morbidity was associated with a smoking history at inclusion (p < 0.01), but not with ESR.
  
  
  CONCLUSIONS
  There was substantial co-morbidity among early RA patients already at disease onset, with considerable new co-morbidity being added during the first five years. Measures of disease activity were associated with the occurrence of a new co-morbidity indicating that the inflammation is of importance in this context.
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. Lena.Innala@vll.se.
authors.forename: Lena
authors.initials: L
authors.lastname: Innala
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. clara.sjoberg86@hotmail.com.
authors.forename: Clara
authors.initials: C
authors.lastname: Sjöberg
authors.affiliation: Department of Rheumatology, Sunderby Hospital, Luleå, 97180, Sweden. bozena.moller@gmail.com.
authors.forename: Bozena
authors.initials: B
authors.lastname: Möller
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. Lotta.Ljung@telia.com.
authors.forename: Lotta
authors.initials: L
authors.lastname: Ljung
authors.affiliation: Department of Rheumatology, Östersund Hospital, Östersund, 83183, Sweden. torgny.smedby@jll.se.
authors.forename: Torgny
authors.initials: T
authors.lastname: Smedby
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. anna.sodergren@umu.se.
authors.forename: Anna
authors.initials: A
authors.lastname: Södergren
authors.affiliation: Department of Rheumatology, Sundsvall Hospital, Sundsvall, 85186, Sweden. staffan.magnusson@lvn.se.
authors.forename: Staffan
authors.initials: S
authors.lastname: Magnusson
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. solbritt.rantapaa.dahlqvist@umu.se.
authors.forename: Solbritt
authors.initials: S
authors.lastname: Rantapää-Dahlqvist
authors.affiliation: Department of Public Health and Clinical Medicine, Rheumatology University Hospital, Umeå, 90185, Sweden. solveig.wallberg.jonsson@umu.se.
authors.forename: Solveig
authors.initials: S
authors.lastname: Wållberg-Jonsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D015897:Comorbidity; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007249:Inflammation / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult
chemical_list: D018501:Antirheumatic Agents
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