Secondhand Smoke Linked to Cognitive Impairment
Higher salivary cotinine concentration may increase risk of cognitive decline and dementia
FRIDAY, Feb. 13 (HealthDay News) -- Secondhand smoke exposure may be associated with an increased risk of developing cognitive impairment, according to research published online Feb. 12 in BMJ.
David J. Llewellyn, Ph.D., of the University of Cambridge in the United Kingdom, and colleagues conducted a cross-sectional analysis of a national population-based study in order to determine the association between secondhand smoke exposure and cognitive impairment. Exposure to secondhand smoke was assessed by measuring salivary cotinine concentration, and cognitive impairment was defined by the lowest 10 percent of scores on several neuropsychological tests. The study included 4,809 non-smoking adults aged 50 or older.
The risk for cognitive impairment increased with increasing salivary cotinine concentrations, the investigators found. Compared with people in the lowest fourth of cotinine concentration, the odds ratios for people in the second, third and highest fourths were 1.08, 1.13 and 1.44, respectively. These results occurred with adjustments made for other risks of cognitive impairment, including age, sex and education level, and were not further significantly affected by adjustment for medical conditions such as cardiovascular disease, the researchers report.
"Our results provide new evidence to suggest that exposure to secondhand smoke may be associated with increased odds of cognitive impairment," the authors conclude, adding that "this is a topic of major public health significance."