Supplementary Material for: Ethnic Differences in Carotid Intima Media Thickness and Plaque Presence - The HELIUS study

Introduction
In the Netherlands, the prevalence of cardiovascular diseases (CVD) is higher among South-Asian Surinamese and lower among Moroccans compared to the Dutch. Traditional risk factors for atherosclerotic CVD do not fully explain these disparities. We aim to assess ethnic differences in plaque presence and intima media thickness (cIMT) and explore to which extent these differences are explained by traditional risk factors.

Methods
We used cross-sectional data from a subgroup of participants enrolled in the multi-ethnic population-based HEalthy Life In an Urban Setting (HELIUS) study who underwent carotid ultrasonography. Logistic and linear regression models were built to assess ethnic differences in plaque presence and cIMT with the Dutch population as reference. Additional models were created to adjust for socioeconomic status, body height and cardiovascular risk factors.

Results
Of the 3022 participants, 1183, 1051 and 790 individuals were of Dutch, South-Asian Surinamese and Moroccan descent. Mean age was 60.9 years (SD 8.0), 52.8% was female. Compared to the Dutch, we found lower odds for plaque presence in Moroccans (0.77, 95% CI 0.62; 0.95) and no significant differences between the South-Asian Surinamese and Dutch population (0.91, 95% CI 0.76; 1.10). After adjustment for CVD risk factors, we found a lower plaque presence in South-Asian Surinamese (0.63, 95% CI 0.48; 0.82). In both Moroccan and South-Asian Surinamese individuals, adjustment for socioeconomic status did not materially change the results. cIMT was lower in South-Asian Surinamese compared to the Dutch (-17.9 µm, 95% CI -27.9; -7.9) and partly explained by ethnic differences in body height as South-Asian Surinamese individuals were, on average, shorter than the Dutch population. No differences in cIMT between Moroccans and Dutch were found.

Conclusions
cIMT and plaque prevalence differ between ethnic groups independent of CVD risk. Lower plaque prevalence in Moroccans was partly attributable to a lower prevalence of traditional CVD risk factors, while body height was an important contributor to differences in cIMT in South-Asians. This study emphasizes the need for ethnic-specific cut-off values for plaque presence and cIMT.

引言
在荷兰，与荷兰人相比，南亚裔苏里南人和摩洛哥人的心血管疾病（CVD）患病率更高，而摩洛哥人的患病率则更低。传统的动脉粥样硬化性CVD风险因素并不能完全解释这些差异。本研究旨在评估不同种族在斑块存在和内膜中层厚度（cIMT）方面的差异，并探讨这些差异在多大程度上可由传统风险因素解释。
方法
本研究使用了来自多民族人群基础研究HEALTHY LIFE In an Urban Setting（HELIUS）的子群体参与者横断面数据，这些参与者接受了颈动脉超声检查。建立了逻辑回归和线性回归模型，以评估与荷兰人群相比，不同种族在斑块存在和cIMT方面的差异。此外，还创建了调整社会经济地位、身高和心血管风险因素的模型。
结果
在3022名参与者中，1183人、1051人和790人分别属于荷兰、南亚裔苏里南人和摩洛哥血统。平均年龄为60.9岁（SD 8.0），女性占52.8%。与荷兰人相比，我们发现摩洛哥人斑块存在的可能性较低（0.77，95% CI 0.62；0.95），而南亚裔苏里南人与荷兰人群之间没有显著差异（0.91，95% CI 0.76；1.10）。在调整心血管风险因素后，我们发现南亚裔苏里南人的斑块存在可能性较低（0.63，95% CI 0.48；0.82）。在摩洛哥人和南亚裔苏里南人中，调整社会经济地位并没有实质性地改变结果。与荷兰人相比，南亚裔苏里南人的cIMT较低（-17.9 µm，95% CI -27.9；-7.9），部分原因是由于种族在身高方面的差异，因为南亚裔苏里南人的平均身高低于荷兰人群。在摩洛哥人和荷兰人之间没有发现cIMT的差异。
结论
在独立于CVD风险的情况下，不同种族的cIMT和斑块患病率存在差异。摩洛哥人斑块患病率较低的部分原因可归因于传统CVD风险因素的较低患病率，而身高是南亚人cIMT差异的重要影响因素。本研究强调了为不同种族制定斑块存在和cIMT的种族特异性阈值值的必要性。