Increased incidence of low-energy fractures in RA patients from northern Sweden
2014 (English)In: Scandinavian Journal of Rheumatology, ISSN 0300-9742, E-ISSN 1502-7732, Vol. 43, no Suppl. 127, Meeting Abstract: PP154, 43-44 p.Article in journal, Meeting abstract (Other academic) Published
Background: Periarticular bone loss is an early sign of joint involvement in rheumatoid arthritis (RA) (1). Patients with RA also have an increased generalized bone loss with development of osteoporosis. Osteoporosis and related fractures constitute an important extra-articular complication in RA. Osteoporosis per se is a known risk factor for fracture in the general population. In addition to general background factors (e.g. old age, low body mass, female gender, immobility) treatment with glucocorticoids and disease activity increase the risk of fractures in osteoporotic patients with RA (1, 2). However, the incidence of fracture is not well explored. The aim of this study was to estimate the incidence of low-energy fractures in RA patients identified within a population-based register of fractures in northern Sweden.
Method: The register of patients with RA (1987 ACR criteria), consecutively included since 1995 (n = 1178), was co-analysed with the Umeå register of injury data base with regard to low-energy fractures. This data base was constructed in 1993 and covers six districts with a population of 118 000 at-risk adults. All individuals admitted to the emergency ward with fractures are included consecutively. The individuals in this study were followed until fracture or to 1 January 2011. The standard incidence ratio (SIR) was calculated. SIR calculations were performed using the method of indirect standardization relative to the standard population of the geographic origin as the RA patients. Confidence intervals were obtained by treating the observed number of events as Poisson variables with expectation equal to the expected number.
Results: Among the RA patients, 329 individuals (246 females and 83 males) were identified with a fracture. The corresponding figures among the controls were 14 102 females and 13 313 males with fractures. The odds ratio (OR) for a fracture in the RA patients was 1.38 (95% CI 1.21–1.57) in females and 1.85 (95% CI 1.46–2.32) in males. Stratification for age showed an increased SIR in the individuals aged > 65 years: OR 1.41 (95% CI 1.20–1.64) in females and OR 1.97 (95% CI 1.48–2.57) inmales. The highest SIR was for hip fracture (females OR 2.51, 95% CI 1.21–4.61 and males OR 3.95, 95% CI 1.28–9.23), with a similar mean age for cases and controls (72–75 years). The duration of time from diagnosis of RA to the first fracture was, during the follow-up, mean (SD) 18.7 (14.0) years in females and 14.4 (11.7) years in males. The RA patients had a similar frequency of fractures indoors as outdoors compared with controls, who had a significantly higher frequency of fractures outdoors.
Conclusions: RA is associated with a higher incidence of fractures. Stratification for age showed increased SIR in those above 65 years of age. The highest SIR was for hip fractures in both females and males.
Place, publisher, year, edition, pages
Informa Healthcare, 2014. Vol. 43, no Suppl. 127, Meeting Abstract: PP154, 43-44 p.
Rheumatology and Autoimmunity
IdentifiersURN: urn:nbn:se:umu:diva-94916DOI: 10.3109/03009742.2014.946235ISI: 000341757300064OAI: oai:DiVA.org:umu-94916DiVA: diva2:760281
Abstract of the 35th Scandinavian Congress of Rheumatology, Stockholm, Sweden, Sept.20th – 23rd, 2014