Department of Epidemiology, Colleges of Medicine and College of Public Health and Health Professions, University of Florida, Gainesville, FL, USA.
Environ Res. 2013 Feb;121:64-70. doi: 10.1016/j.envres.2012.10.013. Epub 2012 Nov 28.
Background Studies show that active smoking may be associated with cognitive decline. However, the consequence of secondhand smoke on cognitive and physical performance remains unclear. The purpose of this study was to assess the association of secondhand smoke with cognitive performance and physical function using a population-based sample.
Data of 2,542 non-smoking participants from the 1999-2002 National Health and Nutrition Examination Survey were analyzed. Secondhand smoke exposure level was estimated using blood cotinine concentrations. Cognitive performance was assessed with the Digit Symbol Substitution Test and self-reported confusion/memory problems. Physical performance was analyzed using visual gait speed (m/s) and self-reported physical function. Multivariate linear and logistic regression models were used to assess the association.
In never smokers, cognitive performance score decreased by 2.03 points (95% confidence interval (CI): -3.00, -1.05) per one unit increase in log-transformed blood cotinine level. After adjusting for potential confounders, including diabetes, hypertension, body mass index, alcohol, and blood lead level, change in cognitive performance score was still statistically significant (-1.17 95% CI: -2.32, -0.02). Similar trends were observed in former smokers. Gait speed decreased by 0.02m/s for one unit increase in log-transformed blood cotinine level. This was evident in both never and former smokers. The relationship remained significant after adjusting for potential confounders in former smokers.
Our study suggests that secondhand smoke may contribute to cognitive decline in never and former smokers. Considering the cross-sectional design and the limitations of this study, the relationship warrants further assessment.
背景研究表明，主动吸烟可能与认知能力下降有关。然而，二手烟对认知和身体表现的影响仍不清楚。本研究的目的是使用基于人群的样本评估二手烟与认知表现和身体功能的关系。
分析了 1999-2002 年全国健康和营养调查中 2542 名不吸烟参与者的数据。使用血液可替宁浓度来估计二手烟暴露水平。认知表现通过数字符号替代测试和自我报告的困惑/记忆问题进行评估。身体表现通过视觉步态速度（m/s）和自我报告的身体功能进行分析。使用多元线性和逻辑回归模型来评估相关性。
在从不吸烟者中，每增加一个单位的对数转换血液可替宁水平，认知表现得分降低 2.03 分（95%置信区间（CI）：-3.00，-1.05）。在调整了包括糖尿病、高血压、体重指数、酒精和血铅水平在内的潜在混杂因素后，认知表现得分的变化仍然具有统计学意义（-1.17 95% CI：-2.32，-0.02）。在以前吸烟者中也观察到类似的趋势。每增加一个单位的对数转换血液可替宁水平，步态速度降低 0.02m/s。在从不吸烟者和以前吸烟者中均如此。在以前吸烟者中，在调整了潜在混杂因素后，这种关系仍然显著。
我们的研究表明，二手烟可能导致从不吸烟者和以前吸烟者的认知能力下降。考虑到横断面设计和本研究的局限性，这种关系需要进一步评估。
