Community Health Care Family Medicine Residency, Tacoma, Washington in affiliation with the Family Medicine Residency Network, University of Washington School of Medicine, Seattle, Washington, United States of America.
Department of Biostatistics, School of Public Health, University of Washington, Seattle, Washington, United States of America.
PLoS One. 2020 Aug 25;15(8):e0237491. doi: 10.1371/journal.pone.0237491. eCollection 2020.
Viral upper respiratory infections are associated with significant health and economic impact. This study sought to determine the efficacy of routine immune system micronutrient supplementation on the incidence, duration and severity of common cold symptoms.
This pilot study was a randomized, double-blinded, placebo-controlled trial of N = 259 with asymptomatic participants aged 18 to 65 in two cold seasons of 2016 and 2017. The treatment group received an immune system targeted micronutrient caplet, while the placebo group received a micronized cellulose caplet externally identical to the treatment caplet. Weekly surveys were sent electronically to participants to document common cold incidence, duration and severity. Primary statistical results were obtained using mixed-effects logistic regressions to account for longitudinal measurements for participants.
The odds of acquiring an upper respiratory infection, adjusted for potential confounders, was estimated to be 0.74 times lower in the treatment group (p = 0.14). The odds of reporting specific symptoms were statistically lower in the treatment arm compared to the placebo arm for runny nose (OR = 0.53, p = 0.01) and cough (OR = 0.51, p = 0.04). Shorter durations of runny nose and cough were also observed in the treatment arm compared to placebo (both p < 0.05). There was no significant difference in severity of symptoms in either group. The observed proportion of reported cold symptoms in the treatment group was lower compared to the placebo group between late January and February in two consecutive cold seasons. Given the physical, workplace and economic impact of upper respiratory infections, this low cost and low risk intervention should be further studied with more robust investigation and meticulous experimental design.
病毒引起的上呼吸道感染会对健康和经济造成重大影响。本研究旨在确定常规免疫系统微量营养素补充对普通感冒症状的发病率、持续时间和严重程度的影响。
这是一项 2016 年和 2017 年两个感冒季节中 259 名无症状参与者（年龄 18 至 65 岁）的随机、双盲、安慰剂对照试验。治疗组服用针对免疫系统的微量营养素胶囊，而安慰剂组服用外观与治疗胶囊相同的微粉化纤维素胶囊。每周通过电子邮件向参与者发送电子调查，以记录普通感冒的发病率、持续时间和严重程度。主要统计结果采用混合效应逻辑回归获得，以考虑参与者的纵向测量。
调整潜在混杂因素后，治疗组上呼吸道感染的发病风险估计降低了 0.74 倍（p = 0.14）。与安慰剂组相比，治疗组报告特定症状的可能性在统计学上较低，包括流鼻涕（OR = 0.53，p = 0.01）和咳嗽（OR = 0.51，p = 0.04）。与安慰剂组相比，治疗组流鼻涕和咳嗽的持续时间也较短（均 p < 0.05）。两组症状严重程度均无显著差异。在两个连续的感冒季节中，1 月下旬至 2 月期间，治疗组报告的感冒症状比例低于安慰剂组。鉴于上呼吸道感染对身体、工作场所和经济的影响，这种低成本、低风险的干预措施应该进一步研究，需要更严格的调查和细致的实验设计。
