Alan G. MacDonald

Global prevalence of ankylosing spondylitis

OBJECTIVES For effective health care provision, knowledge of disease prevalence is paramount. There has been no systematic endeavour to establish continent-based AS estimates, however, prevalence is thought to vary by country and background HLA-B27 prevalence. This study aimed to estimate AS prevalence worldwide and to calculate the expected number of cases. METHODS A systematic literature search was conducted. Prevalence data were extracted and used to calculate the mean prevalence by continent and the expected number of cases based on country-specific prevalence (or, if missing, the prevalence from neighbouring countries). A second estimate was made using the prevalence from countries with similar HLA-B27 prevalences if a country-specific prevalence estimate was not available. RESULTS The mean AS prevalence per 10,000 (from 36 eligible studies) was 23.8 in Europe, 16.7 in Asia, 31.9 in North America, 10.2 in Latin America and 7.4 in Africa. Additional estimates, weighted by study size, were calculated as 18.6, 18.0 and 12.2 for Europe, Asia and Latin America, respectively. There were sufficient studies to estimate the number of cases in Europe and Asia, calculated to be 1.30-1.56 million and 4.63-4.98 million, respectively. CONCLUSION This study represents the first systematic attempt to collate estimates of AS prevalence into a single continent-based estimate. In addition, the number of expected cases in Europe and Asia was estimated. Through reviewing the current literature, it is apparent that the continuing conduct of epidemiological studies of AS prevalence is of great importance, particularly as diagnostic capabilities improve and with the recent development of the criteria for axial SpA.

Fatigue: a principal contributor to impaired quality of life in ANCA-associated vasculitis

OBJECTIVES To describe quality of life (QoL) in an ANCA-associated vasculitis (AAV) cohort and make comparisons with a general population sample. In addition, we aimed to take preliminary steps to identify potential disease and psycho-social factors which may determine QoL impairment. METHODS A population-based case-control study was designed. All AAV patients resident in Grampian, Scotland, were invited to participate as cases. Controls were identified from a random sample of persons registered with four local general practices. Participants completed a questionnaire comprising validated generic and symptom-specific tools in the assessment of QoL. In addition, all cases were clinically assessed and putative disease factors recorded. Cases and controls were compared and, in addition, disease and psycho-social associations were explored for identified QoL impairments. RESULTS In total, 74/90 (82%) cases and 781/2000 (39%) controls participated. Cases reported a significant impairment in physical health (P < 0.0001), but not mental health (P = 0.85), compared with controls, as measured by Short Form-8 (SF-8). Following adjustment for age and sex, persons with AAV were more than twice as likely to report mild/moderate fatigue [odds ratio (OR) 2.0; 95% CI 1.1, 3.8] or severe fatigue (OR 2.5; 95% CI 1.4, 4.5) compared with controls. Furthermore, among cases, fatigue was found to be strongly associated with impaired physical health (P < 0.0001), while disease factors such as disease activity and damage were not (P = 0.60 and 0.27, respectively). CONCLUSIONS Patients with AAV report impaired physical but not mental health. Specifically, fatigue is a principal complaint and appears to be a major determinant of impaired QoL.

Arterial stiffness and cumulative inflammatory burden in rheumatoid arthritis: a dose-response relationship independent of established cardiovascular risk factors.

OBJECTIVE To quantify the relationship between arterial stiffness and cumulative inflammatory burden in patients with RA. METHODS We recruited RA patients without overt arterial disease aged 40-65 years, attending hospital rheumatology outpatient clinics. Standardized research nurse assessment included blood pressure (BP), pulse wave analysis (PWA, SphygmoCor), BMI, fasting blood sample (lipids, glucose, RF and ESR), patient questionnaire (smoking, alcohol, diet, exercise, family history of premature coronary heart disease and Stanford HAQ), current medication and medical record review. Cumulative inflammatory burden was measured as ESR area-under-the-curve (ESR-years) extracted from medical records. Arterial stiffness was measured using PWA [aortic augmentation index (AIX@75)]. Multiple linear regression was used to adjust for age, sex and nine other cardiovascular risk factors. RESULTS We recruited 114 RA patients (mean age 54 years, female 81%, current DMARD 90%, current NSAID 70%, ACR criteria 56%) comprising 1040 RA person-years. Cholesterol, glucose and BMI were similar in women and men. Women had a longer duration of arthritis (10 vs 7 years) and were more likely to be seropositive (85 vs 71%). BP, smoking and alcohol consumption were lower for women. On fully adjusted analysis, an increase of 100 ESR-years was associated with an increase in AIX@75 of 0.51 (95% CI 0.13, 0.88). On fully adjusted analysis restricted to women the increase was 0.43 (95% CI 0.01, 0.85). CONCLUSIONS In RA patients free of overt arterial disease, a dose-response relationship exists between cumulative inflammatory burden and arterial stiffness. This relationship is independent of established CV risk factors.

Relationship Between Arterial Stiffness and Stanford Health Assessment Questionnaire Disability in Rheumatoid Arthritis Patients without Overt Arterial Disease

Objective. To quantify the relationship between Stanford Health Assessment Questionnaire (HAQ) disability and arterial stiffness in patients with rheumatoid arthritis (RA). Methods. A consecutive series of 114 patients with RA but without overt arterial disease, aged 40–65 years, were recruited from rheumatology clinics. A research nurse measured blood pressure (BP), arterial stiffness (heart rate-adjusted augmentation index), fasting lipids, glucose, erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF). A self-completed patient questionnaire included HAQ, damaged joint count, EuroQol measure of health outcome, and Godin physical activity score. Multiple linear regression (MLR) adjusted for age, sex, smoking pack-years, cholesterol, mean arterial BP, physical activity, daily fruit and vegetable consumption, arthritis duration, ESR, and RA criteria. Results. Mean age was 54 years (81% women) with a median HAQ of 1.13 (interquartile range 0.50; 1.75). Median RA duration was 10 years, 83% were RF-positive, and median ESR was 16 mm/h. Mean arterial stiffness was 31.5 (SD 7.7), BP 125/82 mm Hg, cholesterol 5.3 mmol/l, and 24% were current smokers. Current therapy included RA disease-modifying agents (90%), prednisolone (11%), and antihypertensive therapy (18%). Arterial stiffness was positively correlated with HAQ (r = 0.42; 95% CI 0.25 to 0.56). On MLR, a 1-point increase in HAQ disability was associated with a 2.8 increase (95% CI 1.1 to 4.4; p = 0.001) in arterial stiffness. Each additional damaged joint was associated with a 0.17 point increase (95% CI 0.04 to 0.29; p = 0.009) in arterial stiffness. The relationship between EuroQol and arterial stiffness was not statistically significant. Conclusion. In patients with RA who are free of overt arterial disease, higher RA disability is associated with increased arterial stiffness independently of traditional cardiovascular risk factors and RA characteristics.

The Impact of Ankylosing Spondylitis on Work Impairment: Data from the Scotland Registry for Ankylosing Spondylitis

This free journal suppl. entitled: Special Issue: 2014 ACR/ARHP Annual Meeting Abstract Supplement

Evaluation of Clinical Parameters and Quality of Life in Smokers with Ankylosing Spondylitis: Results from the Scotland Registry for Ankylosing Spondylitis.

This free journal suppl. entitled: Special Issue: 2014 ACR/ARHP Annual Meeting Abstract Supplement