Body mass index distribution in rheumatoid arthritis: a collaborative analysis from three large German rheumatoid arthritis databases

Abstract

BackgroundMETARTHROS (Metabolic impact on joint and bone disease) is a nationwide German network to investigate the overlap between inflammatory and metabolic diseases. The objective of this study was to compare the body mass index (BMI) distribution in patients with early and established rheumatoid arthritis (RA) with data from the general population, and to evaluate the association of BMI with patient characteristics and clinical markers.MethodsThe BMI distribution was examined with data collected at inclusion of patients in the early arthritis cohort CAPEA, the biologics register RABBIT, and the National database of the German Collaborative Arthritis Centers. A data source with a representative sample of the German population (German Ageing Survey) was used as a comparator. BMI categories of <18.5 kg/m2 (underweight), 18.5 to <25 kg/m2 (normal weight), 25 to <30 kg/m2 (overweight), and ≥30 kg/m2 (obese) were used. Patients were stratified by age and sex, and compared to controls from the German Ageing Survey. Associations between BMI and markers of disease activity were analysed with non-parametric tests and linear models.ResultsData from 1207 (CAPEA), 12,230 (RABBIT), and 3424 (National database) RA patients and 6202 population controls were evaluated. The mean age was 56, 56, 62, and 62 years, respectively, the mean disease duration was 13 weeks, 9.9 years, and 13.5 years, respectively, and the mean disease activity score (DAS28) was 5.1, 5.2, and 3.1, respectively. In all RA cohorts, obesity was more frequent (23.8 %, 23.4 %, 21.4 %, respectively) than in controls (18.2 %). This applied to all age groups <70 years, was independent of disease duration, and was more pronounced in females. In all cohorts, the age at RA onset was associated with BMI, being higher in overweight/obese patients compared to normal-weight patients. Current smoking was negatively associated with BMI. Linear analyses revealed increased erythrocyte sedimentation rate (ESR) values in underweight and obese females, and an increasing disparity between tender joint counts (TJCs) and swollen joint counts (SJCs) in higher BMI categories.ConclusionsCompared to the general population, a higher prevalence of obesity was observed in all RA cohorts. The dominance of obesity in females and the different behaviour of disease activity markers in relation to the BMI in females indicate that additional parameters need to be considered when analysing the impact of obesity on inflammation in RA.Electronic supplementary materialThe online version of this article (doi:10.1186/s13075-016-1043-9) contains supplementary material, which is available to authorized users.

Myopenia is associated with joint damage in rheumatoid arthritis: a cross‐sectional study

“…Asian patients with RA reported less obesity but more underweight than that of Western countries. In contrast to published RA data from the US and Germany National Database for Rheumatic Diseases, our data of Chinese RA patients confirmed the lower prevalence of obesity (China 4.2% vs. Western 21.4–34.7%) and higher prevalence of underweight (China 17.7% vs. Western 1.1–2.2%) . Furthermore, our RA patients also showed lower prevalence of obesity (4.2% vs. 13.1%) but higher prevalence of underweight (17.7% vs. 3.8%) compared with Chinese adults from Chinese Center for Disease Control and Prevention .…”

“…Western 21.4-34.7%) and higher prevalence of underweight (China 17.7% vs. Western 1.1-2.2%). 29,30 Furthermore, our RA patients also showed lower prevalence of obesity (4.2% vs. 13.1%) but higher prevalence of underweight (17.7% vs. 3.8%) compared with Chinese adults from Chinese Center for Disease Control and Prevention. 31 RA individuals reported almost 2 kg/m 2 BMI values lower than those of healthy controls for the same level of body fat.…”

Long-term trends in rheumatology care

“…Changes in age at disease onset, in health behavior and also in educational statusare variablesofepidemiological relevance when historical and current data are compared. Analyses of differences in disease activity in early and late RA patients [14], in the prevalence of comorbidities in women and men [15] and also the gender-specific influence of overweight on disease activity parameters of RA [16] are examples of the association of sociodemographic factors that need to be taken into account in all analyses. The association of gender, education and region of residence was also evaluated in relation to the employment of patients with rheumatic diseases [11].…”

High prevalence of obesity in rheumatoid arthritis patients: association with disease activity, hypertension, dyslipidemia and diabetes, a multi-center study

“…Obesity is associated with CVR factors in the general population and, more strongly, in RA patients. Thus, in a recent study involving over fifteen thousand RA patients, BMI-defined obesity was more prevalent among patients (20%) than among healthy controls, and even higher figures have been reported (31.6%) [34,36]. The association between obesity and RA disease activity has also been reported before [37].…”