Effects of transdermal nicotine on attention and memory in healthy elderly non-smokers

Abstract

Rationale: Nicotine has been found to improve cognitive functions in patients with Alzheimer's disease, but little is known about its effects in the healthy non-smoking elderly. Objectives: This study aimed to investigate the effects of nicotine on cognitive function in healthy non-smoking or nicotine-naïve elderly subjects. Methods: A transdermal patch containing either 5 mg nicotine or placebo was applied on the back of 63 healthy nicotine-naïve or non-smoking elderly Koreans. Cognitive functions were evaluated with the Short Blessed Test, Rey-Kim Memory Test, and digit span test of the Korean-WAIS, both before and 5.5 h after nicotine administration. The plasma level of nicotine after testing was measured using gas chromatography. Results: The subjects' memory functions in trial 5 of the Rey-Kim Memory Tests improved significantly. Furthermore, the effect on memory slope was significantly correlated with the higher plasma level of nicotine. However, the other tests did not reveal any correlation to a significant degree. Conclusions: These results suggest that nicotine of lower plasma level can improve short-term verbal memory functions in non-smoking or nicotine-naïve healthy elderly people and that some effects are dependent on nicotine plasma levels.