What predicts obesity in patients with rheumatoid arthritis? An investigation of the interactions between lifestyle and inflammation.

OBJECTIVE: To assess whether physical activity, diet or inflammation is a more important determinant of body mass index (BMI) and body fat (BF) in patients with rheumatoid arthritis (RA). METHODS: A total of 150 RA patients (102 female) were assessed for BMI and BF. Their habitual physical activity was assessed with the international physical activity questionnaire (IPAQ) and their energy intake with a 3-day food diary. Pro-inflammatory cytokines (interleukins, IL-1 and IL-6, and tumor necrosis factor-alpha), erythrocyte sedimentation rate, C-reactive protein, disease activity score-28 and physical function (Health Assessment Questionnaire-HAQ) were also measured. RESULTS: BMI correlated inversely with IPAQ (r=-0.511, P=0.000) and positively with energy intake (r=0.331, P=0.016) and HAQ (r=0.133, P=0.042). BF correlated inversely with IPAQ (r=-0.575, P=0.000) and positively with HAQ (r=0.201, P=0.037). Normal weight patients were more physically active compared with those who were either overweight (P=0.006) or obese (P=0.000). Underweight patients consumed significantly fewer calories compared with other patients (P<0.05 in all cases). Cytokines or HAQ did not differ between weight groups. IPAQ was the sole predictor of obesity, whereas energy intake was the sole predictor of underweight. CONCLUSIONS: Inflammation does not seem to influence BMI and BF in RA. As in the general population, high levels of habitual physical activity associate with low BMI and BF in RA. Energy intake is a major determinant of being underweight in those who consume fewer calories. Further research is needed to investigate the suitability of exercise and diet modalities, and their effects on the body composition of RA patients.

Transforming growth factor-beta1 869T/C, but not interleukin-6 -174G/C, polymorphism associates with hypertension in rheumatoid arthritis.

OBJECTIVES: Part of the deleterious effects of systemic inflammation on the cardiovascular system of patients with RA may be exerted via increased propensity to hypertension. IL-6 and TGF-beta1 are important regulators of the inflammatory response. In some, but not all, studies, IL6 -174G/C (rs1800795) and TGFB1 869T/C (rs1982073) gene polymorphisms have been associated with hypertension in the general population. The present study addressed their potential association with hypertension in RA patients. METHODS: TGFB1 869T/C and IL6 -174G/C were identified in 400 RA patients and 422 local, non-RA controls using real-time PCR and melting curve analysis. Binary logistic and linear regression models were used to identify the independence of the effects of the polymorphisms on hypertension. RESULTS: Genotypic and allelic frequencies of the two polymorphisms were similar in RA and controls. Within the RA group, there was no significant association between IL6 -174G/C and hypertension, but TGF 869T-allele carriers had significantly increased prevalence of hypertension compared with CC homozygotes (70.2 vs 55.2%; P = 0.023). This association remained significant after adjustment for other hypertension risk factors and medication (odds ratio = 1.96; 95% CI 1.02, 3.77; P = 0.044), and was more pronounced in patients with increased systemic inflammation. CONCLUSIONS: This study suggests an association of TGFB1 869T/C, but not of IL6 -174G/C, with hypertension in RA patients. If this finding is confirmed in prospective studies, this polymorphism could be used as a screening tool for RA patients with higher risk of developing hypertension and lead to increased surveillance and earlier treatment.

New resting energy expenditure prediction equations for patients with rheumatoid arthritis.

OBJECTIVES: Resting energy expenditure (REE), one of the main components of total energy expenditure, can be measured via indirect calorimetry and/or predicted from equations. The latter may be misleading in RA, as they do not take into account the metabolic alterations occurring in RA. The objectives of this study are to evaluate the accuracy of widely used REE-predictive equations in RA patients against measured REE and to develop RA-specific equations. METHODS: We assessed REE (via indirect calorimetry and several predictive equations), fat-free mass (FFM; via bioelectrical impedance) and disease activity (CRP) in RA patients and healthy controls. Data from 60 RA patients (experimental group) were used to assess the accuracy of existing REE equations and to develop new equations. The new equations were validated in an independent cross-validation group of 22 RA patients. These two groups were merged and two final equations were developed. RESULTS: All equations significantly under-predicted measured REE (from 15% to 18.2%, all at P < 0.001) in the RA experimental group, but not in the control group. After both equations demonstrated a high validity in the cross-validation group, the new final REE prediction equations developed from the total RA sample (n = 82) were: Model 1: REE (kcal/day) = 126.1 x FFM(0.638) x CRP(0.045) (R(2) = 0.70) and Model 2: REE (kcal/day) = 598.8 x weight(0.47) x age(-0.29) x CRP(0.066) (R(2) = 0.62). CONCLUSION: The new equations provide an accurate prediction of REE in RA patients and could be used for clinical monitoring of resting metabolism of these patients without the requirement for specialized personnel.

Lymphotoxin 252A>G polymorphism is common and associates with myocardial infarction in patients with rheumatoid arthritis.

OBJECTIVE: Cardiovascular disease (CVD) is more prevalent and more likely to lead to death in patients with rheumatoid arthritis (RA). Single nucleotide polymorphisms of the genes for lymphotoxin-A (LT-A) and its regulatory protein galectin-2 (LGALS2) have been implicated as genetic risk factors for acute cardiovascular events in the general population: we hypothesised that their risk alleles/genotypes (a) may be more frequent among patients with RA compared with non-RA controls (thus explaining some of the increased CVD in RA), and (b) may be more frequent among patients with RA with prevalent CVD compared with patients with RA without CVD. METHODS: Genomic DNA samples were collected from 388 patients with RA and 399 local population controls without RA. LT-A gene intron 1 252A>G and LGALS2 intron 1 3279C>T single nucleotide polymorphisms were identified using real-time polymerase chain reaction and melting curve analysis. RESULTS: LT-A 252GG homozygotes were significantly more prevalent among patients with RA compared with controls (19.8% vs 11.8%, p = 0.002; OR(GG/GA,AA) = 1.85, 95% CI 1.25 to 2.75, p = 0.002). Patients with RA possessing LT-A 252 GG were significantly more likely to have had a myocardial infarction compared with those with LT-A 252 AA or GA (13% vs 5.5%, p = 0.02; adjusted OR(GG/GA,AA) = 3.03, 95% CI 1.2 to 7.68, p = 0.002). The frequency of LGALS2 polymorphisms was similar between RA and controls and was not associated with CVD among patients with RA. CONCLUSIONS: The LT-A 252GG genotype occurs more frequently among patients with RA than the general population. In RA, this genotype appears to associate with increased likelihood of suffering an myocardial infarction.

Cigarette smoking significantly increases basal metabolic rate in patients with rheumatoid arthritis.

OBJECTIVE: Basal metabolic rate (BMR) is the most important indicator of human metabolism and its abnormalities have been linked to undesirable health outcomes. Cigarette smoking associates with increased BMR in healthy individuals; it is also related with worse disease outcomes in patients with rheumatoid arthritis(RA), in whom BMR is high due to hypercatabolism caused by systemic inflammation. We aimed to investigate whether smokers with RA demonstrated higher BMR levels than their non-smoking counterparts. METHODS: A total of 53 patients with RA (36 female, 17 male, 20 current smokers) were assessed for: BMR(indirect calorimetry), anthropometrical data, fat-free mass (bioelectrical impedance), physical function (health assessment questionnaire; HAQ) and disease activity(disease activity score DAS28 and C reactive protein). RESULTS: RA smokers and non-smokers were not significantly different for age, height, weight, body mass index and fat-free mass. Compared to non-smokers,smokers with RA demonstrated significantly higher BMR (mean (SD) 1513.9 (263.3) vs 1718.1 (209.2) kcal/day; p,0.001) and worse HAQ (1.0 (0.8) vs 1.7 (0.8); p=0.01). The BMR difference was significantly predicted by the interaction smoking/gender (p=0.04). BMR was incrementally higher in light, moderate and heavy smokers (p=0.018), and correlated with the daily number of cigarettes smoked (r=0.68, p=0.04). CONCLUSION: Current cigarette smoking further increases BMR in patients with RA and has a negative impact on patients self-reported functional status. Education regarding smoking cessation is needed for the RA population.

Blockade of tumour necrosis factor-alpha in rheumatoid arthritis: effects on components of rheumatoid cachexia.

OBJECTIVES: Rheumatoid arthritis (RA) is accompanied by increased resting energy expenditure (REE) and decreased fat-free mass (FFM). This is referred to as rheumatoid cachexia and is attributed to high levels of tumour necrosis factor-alpha (TNF-alpha). This study aimed to investigate the effects of anti-TNF-alpha therapy on REE, body composition, physical activity and protein intake in RA patients. METHODS: Twenty RA patients [50% female; age: (mean +/- s.d.) 61.1 +/- 6.8 yrs; body mass index (BMI): 28.3 +/- 3.7 kg/m2] and 12 age-sex-BMI-matched healthy controls were assessed. REE (indirect calorimetry), body composition (bioelectrical impedance), the International Physical Activity Questionnaire (IPAQ), diet, Health Assessment Questionnaire (HAQ), disease activity [disease activity score 28 (DAS28), erythrocyte sedimentation rate (ESR), C-reactive protein] and serum TNF-alpha were measured before (Baseline) as well as 2 weeks (Time-1) and 12 weeks (Time-2) after initiation of anti-TNF-alpha treatment. Controls were only assessed at Baseline. RESULTS: RA patients had significantly higher REE than controls at Baseline (1799.4 +/- 292.0 vs 1502.9 +/- 114.5 kcal/day, P = 0.002). Within the RA group, REE increased significantly between Time-1 and Time-2 (P = 0.001) but not between Baseline and Time-2. Sustained significant increases were observed in IPAQ (P = 0.001) and protein intake (P = 0.001). There were no significant changes in FFM or body fat. ESR (P = 0.002), DAS28 (P < 0.001), HAQ (P < 0.001) and TNF-alpha (P = 0.024) improved significantly. Physical activity (P = 0.001) and protein intake (P = 0.024) were significant between-subject factors for the elevation of REE. CONCLUSIONS: After 12 weeks of anti-TNF-alpha therapy, there were significant improvements in disease activity and physical function, as well as physical activity and protein intake, but no significant changes in REE or FFM. There is a need for longer-term studies in this field.

Polypharmacy among people with rheumatoid arthritis: the role of age, disease duration and comorbidity.

BACKGROUND: People with rheumatoid arthritis (RA) often have comorbidities with associated disability and complex medication regimens. Little published evidence exists about why people with RA require so many medications, although it is logical to hypothesize that this may relate to older age, longer duration of RA, more active RA, worse functional disability and a greater number of comorbidities. OBJECTIVES: We set out to quantify polypharmacy in RA and identify its predictors in an observational cohort. METHODS: The case notes of 348 people receiving secondary care for RA were reviewed to record polypharmacy. The 28-joint Disease Activity Score (DAS28) was calculated and the Health Assessment Questionnaire (HAQ) and the Self-administered Comorbidity Questionnaire (SCQ) were completed. RESULTS: The mean total number of medications was 5.39, with a maximum of 16; of these, a mean of 2.41 medications were directly for RA. A mediational relationship was identified: older age and longer RA duration were significant predictors of a greater total number of medications, but these relationships were explained by the greater number of comorbidities in older participants and those with longer RA duration. Polypharmacy was not related to RA activity or functional disability. CONCLUSIONS: Polypharmacy is common among people with RA and associates with older age and longer RA duration through a greater number of comorbidities. Regular review of the full treatment plan of individuals with RA by pharmacists and other health professionals specializing in rheumatology, to weigh the benefits and risks of each medication and their interactions in light of RA activity and comorbidities, is advocated.

The impact of anti-tumour necrosis factor therapy for rheumatoid arthritis on the use of other drugs and hospital resources in a pragmatic setting.

BACKGROUND: Anti-tumour necrosis factor (anti-TNF) therapy has been an important development for the treatment of rheumatoid arthritis (RA) but the impact of its delivery on hospital resources in still emerging. AIMS: We audited the effect of starting anti-TNF on the use of other anti-rheumatic therapies and hospital resources in a routine secondary care setting. METHODS: A retrospective study of resource use before and after anti-TNF was conducted. Hospital records of 54 RA patients were studied and data taken from the time of commencing anti-TNF to 1 October 2004 and an equal time period prior to commencing anti-TNF. Identical data were collected for 54 controls not on anti-TNF. Relevant figures were extrapolated to per annum rates. Results were analysed using two-factor ANOVAs comparing the pre- versus post-anti-TNF period. Cases on intravenous (IV) versus subcutaneous (SC) anti-TNF were also compared in separate ANOVAs. RESULTS: Mean duration of anti-TNF therapy was 17.04 months (range 3.60-42.36). Mean pre- and 3-months post-anti-TNF Disease Activity Scores (DAS28) were 6.93 and 3.88, respectively. Cases were more likely than controls to be on oral prednisolone pre- and post-anti-TNF. Methylprednisolone requirement, number of disease-modifying anti-rheumatic drugs (DMARDs), telephone helpline contacts and duration as an inpatient reduced significantly post-anti-TNF. Day case admissions increased but outpatient appointments decreased only in cases on IV anti-TNF. CONCLUSIONS: In a pragmatic setting, anti-TNF therapy led to reduced need for steroid injections and other DMARDs, as well as reductions in use of several hospital resources. Wider replication of these findings will be important for planning delivery.

Risk assessment for coronary heart disease in rheumatoid arthritis and osteoarthritis.

BACKGROUND: The risk of coronary heart disease (CHD) is increased in rheumatoid arthritis (RA). The reasons for this remain unknown, but traditional risk factors for CHD identified in the general population may be important contributors. OBJECTIVE: To assess comparatively the prevalence of traditional CHD risk factors and the absolute 10-year CHD risk in patients with RA or osteoarthritis (OA) without known cardiovascular co-morbidity. METHODS: Consecutive Caucasian hospital outpatients with RA (n = 150) or OA (n = 100) aged 40-75 years were assessed for known cardiovascular co-morbidity, age, sex, smoking status, presence of diabetes mellitus (DM), height, weight, systolic blood pressure (BP), total cholesterol (TC) and HDL cholesterol. Absolute 10-year CHD risk for each individual was calculated using the Joint British Societies CHD risk calculator. RESULTS: Prevalence and distribution of known cardiovascular co-morbid conditions were similar in RA (56/150, 37%) and OA (34/100, 34%). The resulting subgroups of patients without known co-morbidity (RA: n = 94; OA: n = 66) were not significantly different for age, sex, DM, smoking, systolic BP or TC: HDL cholesterol ratio. There was no significant difference in the absolute 10-year CHD risk between RA and OA (15.6+/-11.0 versus 14.8+/-9.3, p = 0.63). However, a significant proportion of patients without known cardiovascular disease in both the RA and OA subgroups had a 10-year CHD risk above the 15% or 30% risk levels, indicating the need for possible or definite intervention respectively. Over 80% of RA patients had at least 1 CHD risk factor that could be modified. CONCLUSION: Absolute 10-year CHD risk was not different between RA and OA patients in this study. Substantial numbers of RA and OA patients have potentially modifiable CHD risk factors present. We suggest that CHD risk should be assessed and modifiable risk factors addressed in the routine rheumatology clinic setting.