吸烟可加速男性烟民大脑老化

【吸烟可加速男性烟民大脑老化】英国研究人员1月6日在美国《普通精神病学文献》上报告称，与从不吸烟者相比，吸烟者的思维能力下降很快，吸烟似乎加速了男性烟民的大脑老化。研究人员认为，吸烟伤害心、肺和血管功能，进而影响到向大脑供血，导致大脑不能发挥最佳功能

Impact of Smoking on Cognitive Decline in Early Old Age

The Whitehall II Cohort Study

Séverine Sabia, PhD;Alexis Elbaz, MD, PhD;Aline Dugravot, MSc;Jenny Head, MSc;Martin Shipley, MSc;Gareth Hagger-Johnson, PhD;Mika Kivimaki, PhD;Archana Singh-Manoux, PhD

Arch Gen Psychiatry.Published online February 6, 2012. doi:10.1001/archgenpsychiatry.2011.2016

ContextSmoking is a possible risk factor for dementia, although its impact may have been underestimated in elderly populations because of the shorter life span of smokers.

ObjectiveTo examine the association between smoking history and cognitive decline in the transition from midlife to old age.

DesignCohort study.

SettingThe Whitehall II study. The first cognitive assessment was in 1997 to 1999, repeated over 2002 to 2004 and 2007 to 2009.

ParticipantsData are from 5099 men and 2137 women in the Whitehall II study, mean age 56 years (range, 44-69 years) at the first cognitive assessment.

Main Outcome MeasuresThe cognitive test battery was composed of tests of memory, vocabulary, executive function (composed of 1 reasoning and 2 fluency tests), and a global cognitive score summarizing performance across all 5 tests. Smoking status was assessed over the entire study period. Linear mixed models were used to assess the association between smoking history and 10-year cognitive decline, expressed aszscores.

ResultsIn men, 10-year cognitive decline in all tests except vocabulary among never smokers ranged from a quarter to a third of the baseline standard deviation. Faster cognitive decline was observed among current smokers compared with never smokers in men (mean difference in 10-year decline in global cognition=–0.09 [95% CI, –0.15 to –0.03] and executive function=–0.11 [95% CI, –0.17 to –0.05]). Recent ex-smokers had greater decline in executive function (–0.08 [95% CI, –0.14 to –0.02]), while the decline in long-term ex-smokers was similar to that among never smokers. In analyses that additionally took dropout and death into account, these differences were 1.2 to 1.5 times larger. In women, cognitive decline did not vary as a function of smoking status.

ConclusionsCompared with never smokers, middle-aged male smokers experienced faster cognitive decline in global cognition and executive function. In ex-smokers with at least a 10-year cessation, there were no adverse effects on cognitive decline.

Author Affiliations:Department of Epidemiology and Public Health, University College London, London, England (Drs Sabia, Hagger-Johnson, Kivimaki, and Singh-Manoux, Ms Head, and Mr Shipley); and INSERM U708 (Dr Elbaz), Université Pierre et Marie Curie Paris 6 (Dr Elbaz), and Centre de Gérontologie, Hôpital Ste Périne, Assistance Publique–Hôpitaux de Paris (Dr Singh-Manoux), Paris, and INSERM U1018, Villejuif Cedex (Ms Dugravot and Dr Singh-Manoux), France.