Inflammatory burden interacts with conventional cardiovascular risk factors in patients with psoriatic arthritis: a cross-sectional study

Objective To examine the distribution of systemic inflammation and risk factors of cardiovascular disease (CVD) in patients with psoriatic arthritis (PsA) by comparing with healthy controls. Methods Forty PsA patients and 44 controls were recruited into this cross-sectional study. We evaluated the disease activity and severity [erythrocyte sedimentation rate (ESR), C reactive protein(CRP) and Disease Activity Score (DAS)28], functional ability in patients with predominant axial involvement [Bath AS disease activity index (BASDAI) and Bath AS functional index (BASFI)], traditional CVD risk factors and inflammation between these two groups of patients. Then, we compared risk factors for CVD between 40 consecutive PsA patients and 44 controls, adjusted for body mass index (BMI). The frequencies were compared using chi-square tests for categorical variables. Student's t-tests or Mann-Whitney U-tests were used forcontinuous variables where appropriate. Association between the traditionaland metabolic risk factors and the hs-CRP level were assessed using Spearman correlations. Finally, we also assessed the role of inflammation on the CVD risk factor by using a BMI and hs-CRP-adjusted model. Results The BMI of PsA patients was significantly higher than that of the controls. After adjusting for the BMI, PsA patients had a higher prevalence of hypertension (OR= 5.615, 95%CI 1.844-17.099) and diabetes mellitus (OR=10.655, 95%CI 1.150-98.683) than the controls. PsA patients had significantly increased systolic and diastolic blood pressures [(SBP) and (DBP)], total cholesterol (TC)/high density lipoprotein cholesterol (HDL), insulin resistance, inflammatory markers (hsCRP, white cell count and platelet) and decreased HDL compared to the controls. As excepted, the hsCRP level [4.0 (2.1-13.9) vs 1.7 (1.3-2.2)] , platelet and white cell counts were significantly increased in the PsA group reflecting underlying inflammation. Further adjustment for hsCRP level rendered the differences in the prevalence of hypertension (OR=3.544, 95%CI 1.151-10.914); but the DBP, HDL and sugar levels were non-significantly different between the two groups, while the differences in other parameters were significant. Conclusion The data support the hypothesis that PsA may be associated with hypertension, obesity and dyslipidemia because of the shared inflammation pathway. Key words: Arthritis, psoriatic; Cardivascular diseases; C-reactive protein