Tang Wenjing, Xun Pengcheng, Chen Cheng, Lu Liping, Sood Akshay, Shikany James M, Kahe Ka
Department of Clinical Nutrition, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China; Department of Nutrition, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Department of Epidemiology and Biostatistics, School of Public Health-Bloomington, Indiana University, Bloomington, IN, USA.
J Trace Elem Med Biol. 2021 Mar;64:126683. doi: 10.1016/j.jtemb.2020.126683. Epub 2020 Nov 12.
As an essential micronutrient, zinc plays an important role in modulating the immune system. However, data on the association between zinc concentrations and asthma incidence are sparse, especially in adults.
We prospectively followed up 3682 individuals aged 20-32 years without history of asthma or current asthma at baseline from 1987-1988 to 2015-2016. Zinc concentrations were measured in toenail clippings collected at Exam Year 2 using inductively-coupled-plasma mass spectroscopy. Asthma was diagnosed by a physician and/or reported medication use for asthma control with verification. Cox regression was used to model the association between toenail zinc concentrations and asthma incidence.
Over an average of 22.5 years of follow-up, 508 incident cases of asthma were identified. After adjustment for potential confounders, no statistically significant association was found between zinc concentration and asthma incidence (HR = 0.81; 95% CI: 0.62, 1.07; P = 0.26). The observed association was not materially modified by sex, body mass index, smoking or atopic status. When stratifying data by race, a significant inverse linear association was found among African Americans (per 1 standard deviation increment in toenail zinc concentrations: HR = 0.86; 95% CI: 0.75, 0.99; P = 0.03), but not in Caucasians (HR = 1.07; 95% CI: 0.91, 1.25; P = 0.42), though the test for interaction was not statistically significant (P = 0.099).
Findings from this prospective cohort study do not support a significant longitudinal association between toenail zinc concentrations and incidence of asthma among American young adults. Future studies are needed to confirm our findings.
作为一种必需的微量营养素，锌在调节免疫系统方面发挥着重要作用。然而，关于锌浓度与哮喘发病率之间关联的数据较为稀少，尤其是在成年人中。
我们对1987年至1988年基线时无哮喘病史或当前哮喘的3682名20至32岁个体进行了前瞻性随访，直至2015年至2016年。在第2次检查年份采集的趾甲剪屑中，使用电感耦合等离子体质谱法测量锌浓度。哮喘由医生诊断和/或根据用于哮喘控制的药物使用报告并经核实。采用Cox回归模型分析趾甲锌浓度与哮喘发病率之间的关联。
在平均22.5年的随访期内，共确诊508例哮喘病例。在对潜在混杂因素进行调整后，未发现锌浓度与哮喘发病率之间存在统计学显著关联（风险比=0.81；95%置信区间：0.62，1.07；P=0.26）。观察到的关联在性别、体重指数、吸烟或特应性状态方面未发生实质性改变。按种族对数据进行分层时，在非裔美国人中发现了显著的负线性关联（趾甲锌浓度每增加1个标准差：风险比=0.86；95%置信区间：0.75，0.99；P=0.03），而在白种人中未发现（风险比=1.07；95%置信区间：0.91，1.25；P=0.42），尽管交互作用检验无统计学显著性（P=0.099）。
这项前瞻性队列研究的结果不支持美国年轻成年人中趾甲锌浓度与哮喘发病率之间存在显著的纵向关联。需要进一步的研究来证实我们的发现。
