Nature Reviews UNCORRECTED PROOF NATURE REVIEWS | RHEUMATOLOGY ADVANCE ONLINE PUBLICATION | 1 Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Queen Mary Hospital, 102 Pokfulam Road, Hong Kong, China (K.-H. Yiu, H.-F. Tse, M.-Y. Mok, C.-S. Lau). Correspondence to: C.-S. Lau cslau@hku.hk Ethnic differences in cardiovascular risk in rheumatic disease: focus on Asians Kai-Hang Yiu, Hung-Fat Tse, Mo-Yin Mok & Chak-Sing Lau Abstract | Rheumatic diseases are associated with high cardiovascular morbidity and mortality. Considerable differences exist in the frequency of cardiovascular disease (CVD) risk factors and events among people of different ethnic origins, but little is known of the ethnic variations in the relative distribution of CVD risk factors and the degree of atherosclerosis in patients with rheumatic diseases. Understanding this variation will provide insight into the underlying pathogenesis of CVD in patients with rheumatic diseases, and aid in future studies of the detection and management of this complication. In general, although Asian patients seem to have fewer background CVD risk factors and are less affected by metabolic syndrome (MetS) than their non- Asian counterparts, those with rheumatic disease are equally as susceptible to CVD. Furthermore, it seems that systemic inflammation and mechanisms that do not involve conventional CVD risk factors and MetS have an important role in the development of atherosclerosis in patients with rheumatic diseases. Here we examine the frequency of conventional CVD risk factors and the prevalence of MetS in both Asian and non-Asian patients with selected rheumatic diseases. We also discuss the burden of CVD, as evaluated using various surrogate markers in these patients, and their overall CVD mortality rate. Yiu, K.-H. et al. Nat. Rev. Rheumatol. advance online publication XX Month 2011; doi:10.1038/nrrheum.2011.126 Introduction The epidemiology of cardiovascular disease (CVD) 1 and cardiovascular mortality 2 in the general population varies across different ethnic groups owing to differences in both genetic and host susceptibility factors, dietary practice, and exercise. 3,4 In particular, variation is observed between the frequency of CVD risk factors, such as type 2 diabetes mel- litus (T2DM), 5 metabolic syndrome (MetS) 6 and smoking habit, 7 across different ethnic groups. Population-based studies have shown the prevalence of CVD risk factors including hyperlipidemia, hypertension, T2DM and obesity, for example, is greater in patients from the USA than in those from China, although smoking is more prevalent in Chinese populations. 8,9 Indeed, in 2004, the reported 10-year coronary heart disease event rates for Chinese men and women were 1.5% and 0.6%, respec- tively, in comparison with the corresponding event rates of 8.0% and 2.8% for US men and women. 9 Despite this observation, differences in CVD risk factors and cardio- vascular manifestations between Asian and non-Asian patients with rheumatic disease are not known. Accelerated atherosclerosis leading to premature CVD is recognized as a major cause of long-term morbitiy and mor- tality in patients with rheumatic diseases, such as rheuma- toid arthritis (RA), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc). 10–12 In addition to a high frequency of CVD risk factors, systemic inflammation has a pivotal role in the development of atherosclerosis in these patients. 13 In this Review, we examine the potential differences in the prevalence of conventional CVD risk factors and MetS, the atherosclerotic burden (as assessed by various surrogate markers), and the epidemiology of CVD in patients with selected rheumatic disease. For the purposes of this Review, we have focused on RA, SLE and SSc in Asian and non- Asian populations; the populations studied and the main data gathered are summarized in Figure 1. CVD risk factors in rheumatic disease Rheumatoid arthritis The conventional CVD risk factors, including T2DM, dyslipidemia and hypertension, were first studied when increased risk of CVD in patients with RA became evident. In a study by Gonzalez et al., 14 the prevalence of CVD risk factors was similar among 603 patients with RA and 603 non-RA controls (all from the USA), including T2DM (7% versus 7%, respectively), dyslipidemia (49% versus 52%) and hypertension (52% versus 49%). In the Nurses’ Health Study involving 114,342 US women, of whom 527 had RA, the incidences of T2DM (5% versus 5%), dyslipidemia (35% versus 33%) and hypertension (34% versus 30%) were also similar among patients with or without RA, although patients with RA were more likely to have been smokers in their past (current smokers: 17% versus 20%; past smokers: 49% versus 37%; P <0.01). 15 Overall, these studies demonstrated that the prevalence of conventional CVD risk factors was similar in US patients with RA and non-RA controls, although patients with RA were probably more likely Competing interests The authors declare no competing interests. REVIEWS