The effect of smoking on cognition as measured by Cambridge Neuropsychological Test Automated Battery (CATNAB) and brain-derived neurotrophic factor plasma levels

Abstract

Objectives: To establish an association between cigarette smoking, cognition, and plasma brainderived neurotrophic factor)BDNF(levels in healthy young adults. Methods: This was an ex post facto analytic crosssectional study conducted between March and November 2018. Participants were 73 healthy males)31 smokers and 42 non-smokers(, 17-33 years old. The cognitive function of the participants was assessed through the Cambridge neuropsychological test automated battery)CANTAB(. Blood samples were taken to measure the plasma levels of BDNF and Original Article the results were compared to identify the association between smoking related variables and cognitive test scores and plasma BDNF levels. A p-value of <0.05 was considered statistically significant. Results: Smokers performed significantly worse than non-smokers in the multitasking test, including reaction time and rapid visual information processing. However, no significant association was observed between smoking related variables and cognitive test scores. The only significant positive correlation was found between plasma BDNF levels and the number of cigarettes smoked per day)r=0.480, p=0.024(. No correlation was observed between other smoking related variables and plasma BDNF levels. Conclusion: Plasma BDNF level is positively related to the number of cigarettes smoked per day. Young smokers have significantly impaired sustained attention and less ability to manage conflicting information as compared to age-matched nonsmokers.

Chronic tobacco smoking and neurocognitive impairments in adolescents and young adults: a systematic review and meta-analysis

“…The studies included in the analysis originated from four countries, including the one from United States of America ( 30 ), five from China ( 5 , 18 , 21 , 43 , 54 ), two from Saudi Arabia ( 44 , 55 ), and one from Belgium ( 53 ).…”

“…Demographic data were utilised from a total of (307) chronic tobacco smokers and (315) non-smoking controls, all free of any neuropsychiatric disorders. Since adolescents and young adults were the targets for this study, the mean age range of the adolescent and young adult tobacco smokers ranged from 17 years to 24.7 years, and for the control population their mean age ranged from 16.6 years to 23.3 years ( 30 , 44 , 55 ). Most of the studies were conducted on a predominantly male population except for two studies that had more females than males ( 30 , 53 ).…”

“…The average amount of time in education ranged from 10.1 years to 13.8 years. However, of the included studies that were pooled, several did not include data for the years of education ( 44 , 53 – 55 ). Most of the papers included in this meta-analysis reported pack-years, years of smoking, and cigarettes per day, except for one study that did not report any of these data ( 55 ) and two studies not mentioning pack-years specifically ( 30 , 54 ).…”

“…Most of the papers included in this meta-analysis reported pack-years, years of smoking, and cigarettes per day, except for one study that did not report any of these data ( 55 ) and two studies not mentioning pack-years specifically ( 30 , 54 ). Pack-years ranged from 3.5 to 6.4 ( 18 , 43 , 44 ), years of smoking ranged from 2 years to 7.3 years ( 44 , 54 ), and cigarettes per day ranged from 11.7 Jacobsen et al. ( 30 ) cigarettes per day to 16.9 cigarettes per day ( 21 ) ( Table 1 ).…”

“…This was followed by meta-analytic calculations to reach a quantitative estimate of the impact of chronic tobacco smoking on the neurocognitive functions of the identified cohort. Means (M) and Standard Deviations (SDs) of scores on neurocognitive tests/measures were extracted from six studies ( 5 , 18 , 21 , 30 , 43 , 44 ) and inserted into the Comprehensive Meta-Analysis (CMA) version III software package for analysis ( 45 ). It was only possible to extract data from six studies as the other research papers pooled for the systematic review did not provide relevant statistical data.…”