Supplementary Material for: A Dietary Pattern for High Estimated Total Fat Amount Is Associated with Enhanced Allergy Sensitization and Atopic Diseases among Singapore/Malaysia Young Chinese Adults

<b><i>Introduction:</i></b> Frequent dietary patterns for fast food diets are suggested to be a risk factor for atopic disease development. Excessive dietary fats in fast foods are postulated to promote low-grade chronic inflammation. However, no studies in Asia have yet to characterize the dietary pattern for high-fat foods with atopic diseases. Thus, this study aims to assess the association between dietary fats with the prevalence of atopic diseases in an allergic cohort. <b><i>Methods:</i></b> Through an investigator-administered questionnaire that follows the International Study of Asthma and Allergies in Childhood (ISAAC) protocol, we evaluated the eating habits, lifestyle behaviours, sociodemographics, and atopic symptoms, and history among 11,494 young Chinese adults in Singapore and Malaysia. A skin prick test (SPT) for common house dust mites was also conducted to determine the atopic (allergic) status. We identified 1,550 atopic dermatitis (AD), 1,301 allergic asthma (AS), and 3,757 allergic rhinitis (AR) atopic cases. We derived a novel dietary index, Diet Quality based on Total Fat Amount (DQTFA), to examine the association between eating patterns for estimated total fat amount with various atopic outcomes. <b><i>Results:</i></b> There was a preponderance of subjects having positive SPT reaction (69.0%) with the prevalence of AR being the highest (32.7%), then AD (13.5%), and AS (11.3%). Additionally, there is a significantly higher proportion of subjects with an atopy background and atopic diseases consume diets with a high estimated mean fat amount. The adherence to a dietary pattern of the higher estimated total fat amount was shown to be strongly associated with all atopic diseases and exhibited dose-dependent responses in the univariate analysis. These associations remained significant even with the adjustments for age, gender, body mass index, use of alcohol, sedentary lifestyles, and physical activity. A dietary pattern for high-fat amount is more strongly associated with AS (adjusted odds ratio [AOR]: 1.524; 95% confidence interval [CI]: 1.216–1.725; <i>p</i> &lt; 0.001) and AR (AOR: 1.294; 95% CI: 1.107–1.512; <i>p</i> &lt; 0.001) compared to AD (AOR: 1.278; 95% CI: 1.049–1.559; <i>p</i> &lt; 0.05). Finally, it was shown that having either one of the atopic comorbidities was strongly associated with a dietary pattern of high-fat amounts (AOR: 1.360; 95% CI: 1.161–1.594; <i>p</i> &lt; 0.001). <b><i>Conclusion:</i></b> Our findings altogether provide initial evidence that the dietary pattern of a diet high in fat amount is associated with an increased risk of atopy and atopic diseases in young Chinese adults in Singapore and Malaysia. Balancing the consumption of dietary fats and changing personal dietary habits by choosing foods of the lower fat amount may reduce the associated odds of atopic diseases.

<b><i>引言：</i></b> 频繁摄入快餐类饮食的膳食模式被认为是特应性疾病（atopic disease）发生的危险因素。快餐中过量的膳食脂肪被推测可诱发低度慢性炎症。然而目前亚洲地区尚无研究阐明与特应性疾病相关的高脂食物膳食模式特征。因此本研究旨在评估过敏性队列中膳食脂肪摄入与特应性疾病患病率的关联。<b><i>方法：</i></b> 本研究遵循国际儿童哮喘和过敏研究（International Study of Asthma and Allergies in Childhood, ISAAC）方案，通过研究人员发放的调查问卷，对新加坡与马来西亚的11494名年轻华裔成年人的饮食习惯、生活方式行为、社会人口学特征、特应性症状及病史进行了评估。同时针对常见屋尘螨开展皮肤点刺试验（skin prick test, SPT）以确定研究对象的特应性（过敏）状态。本研究共确诊1550例特应性皮炎（atopic dermatitis, AD）、1301例过敏性哮喘（allergic asthma, AS）及3757例过敏性鼻炎（allergic rhinitis, AR）病例。本研究构建了一种新型膳食指数——基于总脂肪含量的膳食质量指数（Diet Quality based on Total Fat Amount, DQTFA），用以分析基于估计总脂肪摄入量的膳食模式与各类特应性结局的关联。<b><i>结果：</i></b> 研究对象中皮肤点刺试验结果呈阳性者占多数（69.0%），其中过敏性鼻炎（AR）患病率最高（32.7%），其次为特应性皮炎（AD，13.5%）与过敏性哮喘（AS，11.3%）。此外，有特应性病史及特应性疾病的研究对象，其膳食估计平均脂肪摄入量显著更高。单因素分析显示，坚持估计总脂肪摄入量较高的膳食模式与所有特应性疾病均存在显著关联，并呈现剂量反应关系。在校正年龄、性别、体质量指数、饮酒情况、久坐生活方式及体力活动水平后，上述关联仍具有统计学意义。与特应性皮炎（AD）相比，高脂膳食模式与过敏性哮喘（AS，校正比值比（adjusted odds ratio, AOR）=1.524；95%置信区间（confidence interval, CI）：1.216–1.725；<i>p</i> < 0.001）及过敏性鼻炎（AR，AOR=1.294；95%CI：1.107–1.512；<i>p</i> < 0.001）的关联更强。最后，存在任意一种特应性共病与高脂膳食模式显著相关（AOR=1.360；95%CI：1.161–1.594；<i>p</i> < 0.001）。<b><i>结论：</i></b> 本研究结果初步证实，在新加坡与马来西亚的年轻华裔人群中，高脂膳食模式与特应性及各类特应性疾病的发病风险升高相关。通过平衡膳食脂肪摄入、选择低脂肪食物以调整个人饮食习惯，可降低特应性疾病的发生风险。