Smoking, drinking, and incident cognitive impairment: a cohort community based study included in the Gospel Oak project

Moderate alcohol consumption and cognitive risk

We reviewed 143 papers that described the relationship between moderate drinking of alcohol and some aspect of cognition. Two types of papers were found: (1) those that provided ratios of risk between drinkers and nondrinkers (74 papers in total) and (2) those that, although they did not provide such ratios, allowed cognition in drinkers to be rated as "better," "no different," or "worse" than cognition in nondrinkers (69 papers in total). The history of research on moderate drinking and cognition can be divided into two eras: 1977-1997 and 1998-present. Phase I (1977-1997) was the era of neuropsychological evaluation involving mostly young to middle-aged (18-50 years old) subjects. Although initial studies indicated moderate drinking impaired cognition, many later studies failed to confirm this, instead finding no difference in cognition between drinkers and nondrinkers. Phase II (1998-present) was and is the era of mental status exam evaluation involving mostly older (≥55 years old) subjects. These studies overwhelmingly found that moderate drinking either reduced or had no effect on the risk of dementia or cognitive impairment. When all the ratios of risk from all the studies in phase II providing such ratios are entered into a comprehensive meta-analysis, the average ratio of risk for cognitive risk (dementia or cognitive impairment/decline) associated with moderate "social" (not alcoholic) drinking of alcohol is 0.77, with nondrinkers as the reference group. The benefit of moderate drinking applied to all forms of dementia (dementia unspecified, Alzheimer's disease, and vascular dementia) and to cognitive impairment (low test scores), but no significant benefit against cognitive decline (rate of decline in test scores) was found. Both light and moderate drinking provided a similar benefit, but heavy drinking was associated with nonsignificantly higher cognitive risk for dementia and cognitive impairment. Although the meta-analysis also indicated that wine was better than beer or spirits, this was based on a relatively small number of studies because most studies did not distinguish among these different types of alcohol. Furthermore, a number of the studies that did make the distinction reported no difference among the effects of these different types of alcohol. Therefore, at present this question remains unanswered. Analysis also showed that the presence of the apolipoprotein E epsilon 4 allele eliminated the benefit of moderate drinking. However, this was based on a relatively small number of studies and several other studies have found a beneficial effect of the epsilon e4 allele. Further studies are necessary to settle this question. The benefit of moderate alcohol for cognition was seen in both men and women, although the amount and pattern of drinking is very different between the two sexes. Lastly, the finding of unaffected or significantly reduced cognitive risk in light to moderate drinkers was seen in 14/19 countries for which country-specific ratio data were available, with three of the five remaining countries showing nonsignificant reductions as well. Overall, light to moderate drinking does not appear to impair cognition in younger subjects and actually seems to reduce the risk of dementia and cognitive decline in older subjects.

Chronic cigarette smoking: implications for neurocognition and brain neurobiology

Compared to the substantial volume of research on the general health consequences associated with chronic smoking, little research has been specifically devoted to the investigation of its effects on human neurobiology and neurocognition. This review summarizes the peer-reviewed literature on the neurocognitive and neurobiological implications of chronic cigarette smoking in cohorts that were not seeking treatment for substance use or psychiatric disorders. Studies that specifically assessed the neurocognitive or neurobiological (with emphasis on computed tomography and magnetic resonance-based neuroimaging studies) consequences of chronic smoking are highlighted. Chronic cigarette smoking appears to be associated with deficiencies in executive functions, cognitive flexibility, general intellectual abilities, learning and/or memory processing speed, and working memory. Chronic smoking is related to global brain atrophy and to structural and biochemical abnormalities in anterior frontal regions, subcortical nuclei and commissural white matter. Chronic smoking may also be associated with an increased risk for various forms of neurodegenerative diseases. The existing literature is limited by inconsistent accounting for potentially confounding biomedical and psychiatric conditions, focus on cross-sectional studies with middle aged and older adults and the absence of studies concurrently assessing neurocognitive, neurobiological and genetic factors in the same cohort. Consequently, the mechanisms promoting the neurocognitive and neurobiological abnormalities reported in chronic smokers are unclear. Longitudinal studies are needed to determine if the smoking-related neurobiological and neurocognitive abnormalities increase over time and/or show recovery with sustained smoking cessation.

Is there an association between low-to-moderate alcohol consumption and risk of cognitive decline?

The authors evaluated the association of low-to-moderate alcohol consumption with risk of cognitive decline in a census-based cohort study of men and women aged ≥55 years conducted in Zaragoza, Spain (1994-1999). Participants free of dementia at baseline (N = 3,888) were examined after 2.5 and 4.5 years of follow-up. Information on alcohol intake was collected with the EURODEM Risk Factors Questionnaire and the History and Aetiology Schedule. The study endpoint was severe cognitive decline, defined as loss of ≥1 point/year on the Mini-Mental State Examination or a diagnosis of incident dementia (Diagnostic and Statistical Manual of Mental Disorders: DSM-IV, Text Revision criteria). Compared with those for abstainers, the multivariate-adjusted odds ratios for severe cognitive decline for male drinkers of <12 g alcohol/day, drinkers of 12-24 g alcohol/day, and former drinkers were 0.61 (95% confidence interval (CI): 0.31, 1.20), 1.19 (95% CI: 0.61, 2.32), and 1.03 (95% CI: 0.59, 1.82), respectively. The corresponding odds ratios for women were 0.88 (95% CI: 0.45, 1.72), 2.38 (95% CI: 0.98, 5.77), and 1.03 (95% CI: 0.48, 2.23). This study did not support the hypothesis that low-to-moderate alcohol consumption prevents cognitive decline. The inverse association between low-to-moderate alcohol intake and cognitive decline observed in other studies may have been due to inclusion of former drinkers in the abstainers reference category.

Alcohol consumption as a risk factor for dementia and cognitive decline: meta-analysis of prospective studies

The relationships between alcohol consumption and dementia and cognitive decline were investigated in a systematic review including meta-analyses of 15 prospective studies. Follow-ups ranged from 2 to 8 years. Meta-analyses were conducted on samples including 14,646 participants evaluated for Alzheimer disease (AD), 10,225 participants evaluated for vascular dementia (VaD), and 11,875 followed for any type of dementia (Any dementia). The pooled relative risks (RRs) of AD, VaD, and Any dementia for light to moderate drinkers compared with nondrinkers were 0.72 (95% CI = 0.61-0.86), 0.75 (95% CI = 0.57-0.98), and 0.74 (95% CI = 0.61-0.91), respectively. When the more generally classified "drinkers," were compared with "nondrinkers," they had a reduced risk of AD (RR = 0.66, 95% CI = 0.47-0.94) and Any dementia (RR = 0.53, 95% CI = 0.53-0.82) but not cognitive decline. There were not enough data to examine VaD risk among "drinkers." Those classified as heavy drinkers did not have an increased risk of Any dementia compared with nondrinkers, but this may reflect sampling bias. Our results suggest that alcohol drinkers in late life have reduced risk of dementia. It is unclear whether this reflects selection effects in cohort studies commencing in late life, a protective effect of alcohol consumption throughout adulthood, or a specific benefit of alcohol in late life.

Effects of alcoholism severity and smoking on executive neurocognitive function

AIMS

Neurocognitive deficits in chronic alcoholic men are well documented. Impairments include memory, visual-spatial processing, problem solving and executive function. The cause of impairment could include direct effects of alcohol toxicity, pre-existing cognitive deficits that predispose towards substance abuse, comorbid psychiatric disorders and abuse of substances other than alcohol. Cigarette smoking occurs at higher rates in alcoholism and has been linked to poor cognitive performance, yet the effects of smoking on cognitive function in alcoholism are often ignored. We examined whether chronic alcoholism and chronic smoking have effects on executive function.

METHODS

Alcoholism and smoking were examined in a community-recruited sample of alcoholic and non-alcoholic men (n = 240) using standard neuropsychological and reaction-time measures of executive function. Alcoholism was measured as the average level of alcoholism diagnoses across the study duration (12 years). Smoking was measured in pack-years.

RESULTS

Both alcoholism and smoking were correlated negatively with a composite executive function score. For component measures, alcoholism was correlated negatively with a broad range of measures, whereas smoking was correlated negatively with measures that emphasize response speed. In regression analyses, both smoking and alcoholism were significant predictors of executive function composite. However, when IQ is included in the regression analyses, alcoholism severity is no longer significant.

CONCLUSIONS

Both smoking and alcoholism were related to executive function. However, the effect of alcoholism was not independent of IQ, suggesting a generalized effect, perhaps affecting a wide range of cognitive abilities of which executive function is a component. On the other hand, the effect of smoking on measures relying on response speed were independent of IQ, suggesting a more specific processing speed deficit associated with chronic smoking.

Smoking, dementia and cognitive decline in the elderly, a systematic review

Background

Nicotine may aid reaction time, learning and memory, but smoking increases cardiovascular risk. Cardiovascular risk factors have been linked to increased risk of dementia. A previous meta-analysis found that current smokers were at higher risk of subsequent dementia, Alzheimer's disease, vascular dementia and cognitive decline.

Methods

In order to update and examine this further a systematic review and meta-analysis was carried out using different search and inclusion criteria, database selection and more recent publications. Both reviews were restricted to those aged 65 and over.

Results

The review reported here found a significantly increased risk of Alzheimer's disease with current smoking and a likely but not significantly increased risk of vascular dementia, dementia unspecified and cognitive decline. Neither review found clear relationships with former smoking.

Conclusion

Current smoking increases risk of Alzheimer's disease and may increase risk of other dementias. This reinforces need for smoking cessation, particularly aged 65 and over. Nicotine alone needs further investigation.

A population-based study of the association between Trypanosoma cruzi infection and cognitive impairment in old age (the Bambuí Study)

BACKGROUND

Limited clinical data suggest that chronic Trypanosoma cruzi infection, which causes Chagas' disease (ChD), is associated with cognitive impairment. This study investigated this association in a large population-based sample of older adults.

METHODS

Participants in this cross-sectional study comprised 1,449 persons aged > or = 60 years from a Brazilian endemic area (Bambuí). Cognitive functioning was ascertained by the Mini-Mental State Examination (MMSE), considering its score in percentiles [< or =14 (<5th percentile), 15-22 (5th to <25th) and > or =23]. Hypothesized risk factors were T. cruzi infection, ChD-related electrocardiographic (ECG) abnormalities and use of digoxin medication. Potential confounders included depressive symptoms, smoking, stroke, hemoglobin, HDL cholesterol, blood glucose, systolic blood pressure, and use of psychoactive medication.

RESULTS

The prevalence of T. cruzi infection was 37.6%. There was a graded and independent association between infection and the MMSE score (adjusted odds ratios estimated by ordinal logistic regression = 1.99; 95% CI 1.43-2.76). No significant associations between the MMSE score and ECG abnormalities or digoxin medication use were found.

CONCLUSIONS

This study provides for the first time epidemiological evidence of an association between T. cruzi infection and cognitive impairment which was not mediated by either ChD-related ECG abnormalities or digoxin medication use.

Cognitive performance of detoxified alcoholic Korsakoff syndrome patients remains stable over two years

Excessive alcohol consumption is assumed to promote cognitive decline, eventually increasing the risk of dementia. However, little is known about the time course of cognitive functions in patients with chronic alcoholic Korsakoff syndrome (KS). Therefore, we assessed neuropsychological performance in 20 detoxified chronic KS inpatients at time 1 (T1) with a follow-up after two years (T2). The neuropsychological tests assessed verbal and visual short- and long-term memory, working memory, basic executive functions, language, general knowledge, and visual-spatial abilities. Surveys with caregivers and medical records provided information about current and previous disease-related parameters, drinking history, additional pathologies, as well as psychosocial and cognitive therapy within the two-year period. At both sessions, the majority of the KS patients' results were inferior to those of normal subjects. Comparing T1 and T2 revealed no significant decline in any of the investigated functions. Instead, general knowledge, visual long-term memory, and verbal fluency improved slightly after two years, though they still remained within pathological range. Comparing most improved and most deteriorated patients, better outcome occurred more frequently in men than women and was associated with higher premorbid education and fewer detoxifications in the past. In this sample of detoxified KS patients there was no indication of accelerated cognitive decline or onset of dementia-like symptoms over two years.

Alcohol, dementia and cognitive decline in the elderly: a systematic review

BACKGROUND

dementia and cognitive decline have been linked to cardiovascular risk. Alcohol has known negative effects in large quantities but may be protective for the cardiovascular system in smaller amounts. Effect of alcohol intake may be greater in the elderly and may impact on cognition.

METHODS

to evaluate the evidence for any relationship between incident cognitive decline or dementia in the elderly and alcohol consumption, a systematic review and meta-analyses were carried out. Criteria for inclusion were longitudinal studies of subjects aged >or=65, with primary outcomes of incident dementia/cognitive decline.

RESULTS

23 studies were identified (20 epidemiological cohort, three retrospective matched case-control nested in a cohort). Meta-analyses suggest that small amounts of alcohol may be protective against dementia (random effects model, risk ratio [RR] 0.63; 95% CI 0.53-0.75) and Alzheimer's disease (RR 0.57; 0.44-0.74) but not for vascular dementia (RR 0.82; 0.50-1.35) or cognitive decline (RR 0.89; 0.67-1.17) However, studies varied, with differing lengths of follow up, measurement of alcohol intake, inclusion of true abstainers and assessment of potential confounders.

CONCLUSIONS

because of the heterogeneity in the data these findings should be interpreted with caution. However, there is some evidence to suggest that limited alcohol intake in earlier adult life may be protective against incident dementia later.

Smoking history and cognitive function in middle age from the Whitehall II study

BACKGROUND

Studies about the association between smoking and dementia necessarily involve those who have "survived" smoking. We examine the association between smoking history and cognitive function in middle age and estimate the risk of death and of nonparticipation in cognitive tests among smokers.

METHODS

Data are from the Whitehall II study of 10,308 participants aged 35 to 55 years at baseline (phase 1 [1985-1988]). Smoking history was assessed at phase 1 and at phase 5 (1997-1999). Cognitive data (memory, reasoning, vocabulary, and semantic and phonemic fluency) were available for 5388 participants at phase 5; 4659 of these were retested 5 years later.

RESULTS

Smokers at phase 1 were at higher risk of death (hazard ratio [HR], 2.00; 95% confidence interval [CI], 1.58-2.52 among men and HR, 2.46; 95% CI, 1.80-3.37 among women) and of nonparticipation in cognitive tests (odds ratio [OR], 1.32; 95% CI, 1.16-1.51 among men and OR, 1.69; 95% CI, 1.41- 2.02 among women). At phase 5 in age- and sex-adjusted analyses, smokers compared with those who never smoked were more likely to be in the lowest quintile of cognitive performance. After adjustment for multiple covariates, this risk remained for memory (OR, 1.37; 95% CI, 1.10-1.73). Ex-smokers at phase 1 had a 30% lower risk of poor vocabulary and low verbal fluency. In longitudinal analysis, the evidence for an association between smoking history and cognitive decline was inconsistent. Stopping smoking during the follow-up period was associated with improvement in other health behaviors.

CONCLUSIONS

Smoking was associated with greater risk of poor memory. Middle-aged smokers are more likely to be lost to follow-up by death or through nonparticipation in cognitive tests. Ex-smokers had a lower risk of poor cognition, possibly owing to improvement in other health behaviors.

Chronic insomnia and cognitive functioning among older adults

Chronic insomnia and cognitive impairment are both common complaints among older adults. This study explores the association between chronic insomnia and changes in cognitive functioning among older adults. The study population comprised two groups: 64 older adults without insomnia and 35 older adult insomniacs. The cognitive capacity of each participant was tested at the participant's home using the computerized "MindFit" test (CogniFit, Inc.). In five categories of cognitive functioning, older adult insomniacs displayed impaired performance compared to older adult good sleepers. Specifically, significant differences were found between insomniacs and good sleepers on memory span, allocating attention to a target, time estimation, executive functioning, and integration of two dimensions (visual and semantic) tests. The findings imply that insomnia may have detrimental effects on some cognitive functions in healthy older adults.

Lifestyle-related factors in predementia and dementia syndromes

Cognitive decline and dementia have a deep impact on the health and quality of life of older subjects and their caregivers. Since the therapeutic options currently available have demonstrated limited efficacy, the search for preventive strategies for cognitive decline and dementia are mandatory. A possible role of lifestyle-related factors was recently proposed for age-related changes of cognitive function, predementia syndromes and the cognitive decline of degenerative (Alzheimer's disease [AD]) or vascular origin. At present, cumulative evidence suggests that vascular risk factors may be important in the development of mild cognitive impairment (MCI), dementia and AD. Moderate alcohol drinking has been proposed as a protective factor against MCI and dementia in several longitudinal studies, but contrasting findings also exist. The Mediterranean diet could therefore be an interesting model with which to further study the association between dietary patterns and cognitive functioning, given the suggested role of many components of this diet (monounsaturated fatty acids, polyunsaturated fatty acids, cereals and red wine) in contrasting cognitive impairment and dementia. The association between low education and predementia and dementia syndromes is supported by the majority of studies, but very few studies have investigated whether this association may be attributed with lifestyle factors that covary with education. Studies in the literature seem to identify in physical exercise one promising strategy in decreasing cognitive decline, but some of the limitations of these studies do not allow us to draw definite conclusions. At present, in older subjects, healthy diets, antioxidant supplements, the prevention of nutritional deficiencies, and moderate physical activity could be considered the first line of defense against the development and progression of predementia and dementia syndromes. However, in most cases, these were only observational studies, and results are awaited from large multicenter randomized clinical trials in older persons that may clarify the possible synergy, for example, between moderate exercise, physical activity and healthy Mediterranean diet on cognition in the elderly.

Alcohol drinking and cognitive functions: findings from the Cardiovascular Risk Factors Aging and Dementia (CAIDE) Study

BACKGROUND

Moderate alcohol drinking is suggested to be beneficial for cognitive functions, but the results of previous studies have varied greatly. Little is known about the effects of midlife alcohol drinking on the cognitive functions later in life.

METHODS

Participants were derived from random, population-based samples studied in Eastern Finland in 1972, 1977, 1982, or 1987. A total of 1,341 participants were reexamined in 1998, after an average follow-up period of 21 years, at ages 65-79 years.

RESULTS

The participants who did not drink alcohol at midlife had a poorer performance in episodic memory, psychomotor speed, and executive function in late life as compared with infrequent and frequent drinkers, adjusted for sociodemographic and vascular factors. Also late-life nondrinkers had poorer psychomotor speed and executive function. These findings were evident especially among nonsmokers. Further, no interactions between apolipoprotein E4 and alcohol or sex and alcohol were found.

CONCLUSIONS

Alcohol drinking both at midlife and later is favorably related to the function in several cognitive domains, including episodic memory, psychomotor speed, and executive function, in late life. However, it is not clear whether the association is causal, what is the possible mechanism, and what would be a safe limit of drinking for the best cognitive function.

Cognitive functioning in late life: the impact of moderate alcohol consumption

PURPOSE

Sex differences in the association between moderate alcohol consumption and cognitive functioning were examined during 4 years.

METHODS

Participants were 2716 US older adults 70 years and older (mean age, = 76.02 years) who were free of cognitive impairment from the Second Longitudinal Study of Aging (1994 to 2000). Multiple logistic regression models were used to predict cognitive functioning (adapted Telephone Interview for Cognitive Status) from average daily alcohol intake (no drink, one drink or less daily, and more than one drink daily) during 4 years after controlling for covariates.

RESULTS

Sex differences in the association between alcohol consumption and cognitive functioning were found (p < 0.01). Older adults with alcohol consumption of one drink or less per day had a lower odds of low cognitive functioning compared with abstainers for women (adjusted odds ratio [AOR], 0.67; 95% confidence interval [CI], 0.55-0.83), but not men (AOR, 0.96; 95% CI, 0.69-1.34).

CONCLUSIONS

For older adults with a level of cognitive functioning within normal ranges, moderate amounts of alcohol, an average of one drink or less daily, was protective for women, but not men. Caution should be used in suggesting moderate alcohol consumption to maintain cognitive functioning because of the risks of consuming alcohol.

Cognitive status of young and older cigarette smokers: data from the international brain database

Previous studies that have examined the impact of cigarette smoking on cognition have revealed mixed results; some studies report no impact and others report detrimental effects, especially in older individuals. Few studies, however, have examined the effects of cigarette smoking on both young and old healthy individuals using highly robust and standardized methods of cognitive assessment. This study draws on an international database to contrast cognitive differences between younger and older individuals who regularly smoke cigarettes and non-smokers. Data were sampled from 1000 highly screened healthy individuals free of medical or psychiatric health complications. A cohort of 62 regular smokers (n = 45 < 45 years of age; n = 1745 years) with a Fagerstrom nicotine dependency score of 1 or more were identified and matched to a cohort of 62 healthy nonsmokers (n = 43 < 45 years; n = 1945 years) on demographic variables and estimated intelligence. Performances on cognitive measures of attention, reaction time, cognitive flexibility, psychomotor speed, and memory were considered for analysis. As a group, smokers performed more poorly than nonsmokers on one measure of executive function. A significant age and smoking status interaction was identified with older smokers performing more poorly than older nonsmokers and younger smokers on a measure of long-delayed recall of new information. Cigarette smoking is associated with isolated and subtle cognitive difficulties among very healthy individuals.

Neurocognitive consequences of cigarette smoking in young adults—a comparison with pre-drug performance

The present study examined effects of current and past regular cigarette smoking in young adult subjects. One hundred and twelve 17-21-year-old subjects, assessed since infancy, were evaluated using a battery of neurocognitive tests for which commensurate measures were obtained at 9-12 years of age, prior to the initiation of regular smoking. Smokers, determined by urinalysis and self-report, were categorized as heavy (>9 cigarettes per day) and light (<9 cigarettes per day) current smokers and former smokers, the latter having smoked cigarettes regularly in the past but not for at least 6 months. A third of the subjects were currently smoking cigarettes regularly with half of these being heavy smokers. Among former smokers, the average duration of smoking was slightly less than 2 years. Overall IQ, memory, processing speed, vocabulary, attention and abstract reasoning were the primary outcomes with comparisons being made between each of the three user groups and a control group who never smoked regularly. After accounting for potentially confounding factors including clinical assessment, marihuana use and pre-drug performance in the relevant cognitive domain, current regular smokers did significantly worse than non-smokers in a variety of cognitive areas predicated upon verbal/auditory competence including receptive and expressive vocabulary, oral arithmetic, and auditory memory. This impact of current smoking appears to behave in a dose-response and duration-related fashion. In contrast, former smokers differed from the non-smokers only in the arithmetic task. These results suggest that regular smoking during early adulthood is associated with cognitive impairments in selected domains and that these deficits may be reversed upon cessation. Together, the findings add to the body of evidence to be used in persuading adolescents and young adults against the initiation of smoking and, if currently smoking, the advantages of stopping.

Smoking is associated with neurocognitive deficits in alcoholism

BACKGROUND

Impaired problem solving, visual-spatial processing, memory, and cognitive proficiency are consequences of severe alcoholism. Smoking is much more prevalent among alcoholics than the general population, yet the possible neurocognitive effects of cigarette smoking in alcoholism have not been studied, despite evidence that long-term smoking is associated with neurocognitive deficits.

OBJECTIVE

Determine whether smoking contributes to neurocognitive deficits associated with alcoholism.

DESIGN

Neurocognitive function was examined in a community-recruited (n=172) sample of men. Alcohol problems/alcoholism were measured by the lifetime alcohol problems score (LAPS), DSM-IV diagnosis, and monthly drinking rate. Smoking was measured in pack-years. Neurocognitive function was measured with IQ (short version of WAIS-R), and cognitive proficiency (fast, accurate performance).

RESULTS

Both alcoholism and smoking were negatively correlated with neurocognitive function. When alcoholism and smoking were included in regression models, smoking remained a significant predictor for both measures, but alcoholism remained significant only for IQ.

CONCLUSIONS

Both smoking and alcoholism were related to neurocognitive function. Smoking may explain some of the relationship between alcoholism and neurocognitive function, perhaps especially for measures that focus on proficiency. Future studies are necessary to more fully understand the effects of smoking on neurocognitive function in alcoholism.

Relationship between Lifetime Smoking, Smoking Status at Older Age and Human Cognitive Function

Cigarette smoking is a major risk factor for clinical cardiovascular disease and may also be associated with poorer cognitive functioning in older age. We measured lifetime cigarette smoking, smoking status and cognitive function in over 2,000 men and women from the general population aged over 50 years with subclinical atherosclerosis (ankle brachial pressure index<or=0.95 but no history of clinical cardiovascular disease). In this population, an association was found between greater lifetime smoking and poorer cognitive function in men and between smoking cessation and better cognitive function in women. The former relationship appeared to reflect an association between smoking habit and prior cognitive function (in early life), whereas the latter remained significant after adjustment for tests of crystallised cognitive function, suggesting a relationship between continuing to smoke (as opposed to quitting) and age-related cognitive decline. Both relationships were independent of the degree of atherosclerosis (as measured using the ankle brachial pressure index), suggesting alternative underlying mechanisms for the association between smoking and human adult cognitive function.

Binge drinking in midlife and dementia risk

BACKGROUND

Studies examining the long-term effects of alcohol consumption on cognitive functioning have produced conflicting results. Our goal was to determine whether a long follow-up period combined with information about drinking patterns, in addition to total alcohol consumption, would provide new insights about the relationship of alcohol use with dementia risk.

METHODS

A population-based cohort of 554 Finnish twins, who had provided data on alcohol consumption in questionnaires in 1975 and 1981, was followed for 25 years. Subjects were age 65 years or older at the time of dementia assessment in 1999-2001. Dementia risk was analyzed with respect to varying patterns of alcohol use by log-linear modeling, adjusted for age, sex, and education.

RESULTS

By the end of follow-up, 103 participants had developed dementia. Binge drinking (ie, alcohol exceeding the amount of 5 bottles of beer or a bottle of wine on 1 occasion at least monthly), as reported in 1975, was associated with a relative risk of 3.2 (95% confidence interval=1.2-8.6) for dementia. Passing out at least twice as a result of excessive alcohol use during the previous year, as reported in 1981, was associated with a relative risk of 10.5 (2.4-46) for dementia in drinkers.

CONCLUSIONS

Binge drinking in midlife is associated with an increased risk of dementia.

Prévalence des déficiences et disparités sociales

BACKGROUND

Population ageing and longer duration of the working career could increase the prevalence of impairments and disabilities whereas there have been few data to help prevention and care. This study aimed at describing the prevalence of various types of impairments and assessing their social inequalities in the Lorraine population (north-eastern France).

METHODS

The sample included 6.214 subjects aged 15 or more from 8.000 households randomly selected in the Lorraine population. A mailed questionnaire including socio-demographical characteristics, job, and various types of impairments was used. The data were analysed with the chi2 independence test, the adjusted odds ratio (OR) and the Mantel-Haenszel test.

RESULTS

The prevalence of at least one impairment was 30% in both sexes. It varied from about 20% for subjects aged less than 40 years to about 60% for the subjects aged 70 years or more. It was higher in men than in women among the individuals aged more than 50 years (OR adjusted on age: 1.22, 95% CI: 1.04-1.44). The impairments were generally multiple for the subjects aged over 50. The prevalence of at least one impairment was higher for workmen (OR adjusted on age: 2.11, 95% CI: 1.68-2.66), farmers, craftsmen, traders and heads of firms (OR adjusted on age: 1.60, 95% CI: 1.17-2.18) and for employees (OR adjusted on age: 1.62, 95% CI: 1.29-2.03) in comparison with executives, intellectual professionals and teachers. For workmen a higher prevalence was observed for all types of impairments: intellectual and psychological functions, language, hearing, vision, visceral functions, and skeleton and posture. Farmers, craftsmen, traders, heads of firms and employees showed an excess for most types of impairments. Social inequalities were significant for various age groups during their period of occupational activity, but not after retirement. Unemployed people also had an excess of impairments.

CONCLUSION

The prevalence of impairments strongly increased with advancing age. Marked inequalities were observed between various socio-occupational categories. Men were more affected than the women over 50 years of age. Impairments represent a health index which is useful for prevention to reduce their causes and consequences.

Effects of moderate alcohol consumption on cognitive function in women

BACKGROUND

The adverse effects of excess alcohol intake on cognitive function are well established, but the effect of moderate consumption is uncertain.

METHODS

Between 1995 and 2001, we evaluated cognitive function in 12,480 participants in the Nurses' Health Study who were 70 to 81 years old, with follow-up assessments in 11,102 two years later. The level of alcohol consumption was ascertained regularly beginning in 1980. We calculated multivariate-adjusted mean cognitive scores and multivariate-adjusted risks of cognitive impairment (defined as the lowest 10 percent of the scores) and a substantial decline in cognitive function over time (defined as a change that was in the worst 10 percent of the distribution of the decline). We also stratified analyses according to the apolipoprotein E genotype in a subgroup of women.

RESULTS

After multivariate adjustment, moderate drinkers (those who consumed less than 15.0 g of alcohol per day [about one drink]) had better mean cognitive scores than nondrinkers. Among moderate drinkers, as compared with nondrinkers, the relative risk of impairment was 0.77 on our test of general cognition (95 percent confidence interval, 0.67 to 0.88) and 0.81 on the basis of a global cognitive score combining the results of all tests (95 percent confidence interval, 0.70 to 0.93). The results for cognitive decline were similar; for example, on our test of general cognition, the relative risk of a substantial decline in performance over a two-year period was 0.85 (95 percent confidence interval, 0.74 to 0.98) among moderate drinkers, as compared with nondrinkers. There were no significant associations between higher levels of drinking (15.0 to 30.0 g per day) and the risk of cognitive impairment or decline. There were no significant differences in risks according to the beverage (e.g., wine or beer) and no interaction with the apolipoprotein E genotype.

CONCLUSIONS

Our data suggest that in women, up to one drink per day does not impair cognitive function and may actually decrease the risk of cognitive decline.

Childhood IQ, smoking, and cognitive change from age 11 to 64 years

We investigated whether smoking is a risk factor for relative cognitive decline from age 11 to 64 years. The potentially confounding effects of childhood IQ, occupational status, level of education, presence of heart disease, hypertension, and lung function were examined. Subjects were nondemented and living independently. They were all born in 1936, had been participants in the same Scottish national IQ survey in 1947, and were reexamined at age about 64 years in 2000-2002. Current smokers and nonsmokers had significantly different mental test scores at age 64. This difference remained after adjustment for childhood IQ. Multiple linear regression identified childhood IQ, level of education, occupational code, lung function, and smoking history as significant independent predictors of mental function at age 64. In this sample, smoking makes a small (<1% variance) independent negative contribution to cognitive aging.

Alcohol drinking in middle age and subsequent risk of mild cognitive impairment and dementia in old age: a prospective population based study

OBJECTIVE

To evaluate the relation between midlife alcohol consumption and mild cognitive impairment and dementia in old age, and the possible modification of this relation by apolipoprotein E.

DESIGN

Prospective, population based study.

SETTING

Populations of Kuopio and Joensuu, eastern Finland.

PARTICIPANTS

Of 1464 men and women aged 65-79 years randomly selected from population based samples studied in 1972 or 1977, 1018 (70%) were re-examined in 1998 (after an average follow up of 23 years).

MAIN OUTCOME MEASURES

Mild cognitive impairment and dementia in old age.

RESULTS

Participants who drank no alcohol at midlife and those who drank alcohol frequently were both twice as likely to have mild cognitive impairment in old age as those participants who drank alcohol infrequently. The risk of dementia related to alcohol drinking was modified by the presence of the apolipoprotein e4 allele. The carriers of apolipoprotein e4 had an increased risk of dementia with increasing alcohol consumption: compared with non-carriers who never drank, the odds ratio for carriers who never drank was 0.6, for infrequent drinkers it was 2.3, and for frequent drinkers was 3.6 (the overall interaction term "drinking frequency(*)apolipoprotein e4" was significant (P = 0.04), as were the interactions "infrequent drinking(*)apolipoprotein e4" (P = 0.02) and "frequent drinking(*)apolipoprotein e4" (P = 0.03)). Non-carriers of apolipoprotein e4 had similar odds ratios for dementia irrespective of alcohol consumption.

CONCLUSION

Alcohol drinking in middle age showed a U shaped relation with risk of mild cognitive impairment in old age. Risk of dementia increased with increasing alcohol consumption only in those individuals carrying the apolipoprotein e4 allele.

A 2-year follow-up study of cigarette smoking and risk of dementia

The report focused on investigating the relationship between cigarette smoking and dementia in elderly people through prospective studies. We did a 2-year follow-up study of elderly people. A total of 2820 participants aged 60 years old and over from six communities of Chongqing agreed to take part. Dementia was diagnosed with MMSE (Mini-Mental State Examination) and DSM-III-R (Diagnostic and Statistical Manual of Mental Disorders). Participants were classified as never smokers, past smokers, and current smokers. During follow-up, we recorded incident cases of dementia. The association of smoking and dementia was investigated using proportional hazards regression analysis. A total of 121 incident cases of dementia were detected, of which 84 (69%) were Alzheimer's disease, 17 (14%) were vascular dementia, and 21(17%) were other dementia. Compared with never smokers, current smokers had an increased risk of Alzheimer's disease (RR = 2.72; 95% CI = 1.63-5.42) and vascular dementia (RR = 1.98; 95% CI = 1.53-3.12) adjusting for age, sex, education, blood pressure, and alcohol intake. Compared with light smokers, the adjusted risk of Alzheimer's disease was significantly increased among smokers with a medium level of exposure (RR = 2.56; 95% CI = 1.65-5.52), with an even higher risk of Alzheimer's disease in the heavy smoking group (RR = 3.03; 95% CI = 1.25-4.02). Smoking was associated with the risk of dementia. This study suggests that both smoking status and amount is associated with dementia.

Differences between smokers and nonsmokers in regional gray matter volumes and densities

BACKGROUND

Magnetic resonance imaging (MRI) studies have demonstrated large-scale brain abnormalities in cigarette smokers, such as ventricular enlargement and atrophy. Converging lines of evidence point to functional differences between smokers and nonsmokers in specific brain regions, namely the lateral prefrontal cortex (PFC), anterior cingulate cortex (ACC), ventral striatum, and thalamus. Using MRI, we examined these regions for differences in gray matter between smokers and nonsmokers.

METHODS

Thirty-six otherwise healthy adults (19 smokers and 17 nonsmoking control subjects) underwent three-dimensional Fourier-transform spoiled-gradient-recalled acquisition MRI of the brain. Both hand-drawn regions of interest and the computer program voxel-based morphometry were used to assess group differences in regional gray matter volumes and densities, respectively.

RESULTS

Smokers had smaller gray matter volumes and lower gray matter densities than nonsmokers in the PFC bilaterally, along with smaller volumes in the left dorsal ACC and lower gray matter densities in the right cerebellum. Smokers also had negative associations between pack-year smoking history and PFC gray matter densities.

CONCLUSIONS

Smokers and nonsmokers differed in regional gray matter in brain areas previously linked with nicotine dependence. These findings might reflect effects of chronic smoking, predisposing traits that lead to smoking, or some combination of these factors.

Alcohol, estrogen replacement therapy, and visuospatial processes in postmenopausal women

BACKGROUND

Studies suggest that moderate drinking may benefit cognition and the effect may favor women. This study investigated effects of moderate drinking on visuospatial functioning in postmenopausal women. Visuospatial processes are sensitive to alcohol abuse and are thought to be sensitive to hormonal fluctuations. Three questions were posed in order to: explore visuospatial processes in moderate-drinking and abstaining postmenopausal women, assess visuospatial differences in women using no estrogen replacement therapy (No-ERT), ERT alone (ERT-only), and ERT with progestin (ERT+Pro), and identify alcohol/ERT interactions associated with visuospatial performance.

METHODS

Two hundred fourteen postmenopausal women participated (75 No-ERT; 63 ERT-only; 76 ERT+Pro. All were moderate drinkers or teetotalers and all received the Block Design test from the Wechsler Adult Intelligence Scale-Revised. A raw score was calculated and progress at 30-sec intervals was assessed.

RESULTS

ANOVA revealed an alcohol main effect [F(3,202) = 4.74; p < 0.004] on 60- to 120-sec change scores. Teetotalers had significantly smaller change scores (less improvement) compared with all levels of drinkers. ANOVA on design 9 (the most difficult trial) revealed an ERT main effect [F(3,202) = 4.37; p < 0.02]. ERT nonusers scored significantly lower than ERT-only and ERT+Pro groups. A design 9 trend toward an alcohol x ERT interaction was noted [F(6,202) = 1.93; p < 0.08], and a design 9 time x alcohol interaction was revealed [F(6,404) = 2.65; p < 0.02].

CONCLUSIONS

These data suggest that moderate drinking may be positively associated with visuospatial processes in postmenopausal women. They also suggest that ERT, alone and with progestin, is positively associated with visuospatial processes, but only when the task is difficult. These findings support Kaplan's assertion that subtle performance deficits may not be detectible with traditional endpoint measures. A provocative alcohol x ERT trend suggests that alcohol consumption should be considered in studies of ERT effects on cognitive ability.

Cigarette smoking and cognitive decline in midlife: evidence from a prospective birth cohort study

OBJECTIVES

The authors investigated the effects of cigarette smoking on midlife cognitive performance.

METHODS

Multiple regression was used to test the association between cigarette smoking and changes in cognitive test scores among male and female members of the British 1946 birth cohort aged between 43 and 53 years.

RESULTS

Smoking was associated with faster declines in verbal memory and with slower visual search speeds. These effects were largely accounted for by individuals who smoked more than 20 cigarettes per day and were independent of sex, socioeconomic status, previous (adolescent) cognitive ability, and a range of health indicators.

CONCLUSIONS

The present results show that heavy smoking is associated with cognitive impairment and decline in midlife. Smokers who survive into later life may be at risk of clinically significant cognitive declines.

Smoking and cognitive performance in the community elderly: a longitudinal study

This prospective study investigated the association between smoking and cognitive performance in a community of nondemented elderly subjects aged 65 or older. All subjects were categorized as current smokers, former smokers, or never smokers. The lifetime cigarette exposure was computed. At baseline, we found the abstainers from smoking had better cognitive performances; however, the differences were not significant after adjusting for age, education, hypertension, diabetes, and vascular events. The lifetime cigarette exposure was not predictive of the cognitive status. At a 3-year follow-up, neither the smoking status nor the lifetime cigarette exposure predicted the declination of cognition.

Quality of accommodation and risk of depression in later life: an analysis of prospective data from the Gospel Oak Project

OBJECTIVE

To investigate the association between observer-rated quality of internal accommodation and risk of onset of depression.

DESIGN

A secondary analysis of data from a cross-sectional survey of residents aged 65 or over in a north London electoral ward who were followed up after a one-year interval.

METHOD

Pervasive depression (SHORT-CARE) was assessed at both interviews. Quality of accommodation (on a five-point scale) was assessed by a single interviewer in a random sample at baseline. Potential confounding factors which were considered included age, sex, social class, level of handicap, level of social support, baseline sub-case depressive symptoms, cognitive function, income, accommodation tenure and area-level housing quality.

RESULTS

In participants without depression at baseline (n=131), worse accommodation was associated with depression after one year (odds ratio (OR) between three accommodation groups 3.3, 95% confidence intervals (CI) 1.5-7.8). Adjustment for the potential confounding factors made little difference (adjusted OR 3.3). The association was principally in people cohabiting (OR 12.4) rather than living alone (OR 1.1).

CONCLUSIONS

An observer's impression of accommodation quality was a strong and independent predictor of depression in this sample. The stronger association in people who were cohabiting may reflect increased exposure to the internal environment.

Effects of habitual cigarette smoking on higher cortical function in patients with unruptured cerebral aneurysms

Postoperative changes in higher cortical function and cerebral blood flow (CBF) were investigated in patients with unruptured cerebral aneurysms to assess the effect of habitual smoking on the known transient changes after aneurysm surgery. Fifty-six adults with unruptured cerebral aneurysms, including 11 heavy smokers (smoking index > or = 600) and 45 non-smokers, were evaluated using three neuropsychological examinations, the Mini-Mental State Examination, the Maze test, and the Kana-hiroi test, and single photon emission computed tomography to measure CBF before and after surgery. Neuropsychological changes were assessed by reliable change indices to take into account the practice effects. The scores of at least one examination decreased in 15 of 56 patients 1 month after surgery. On the Maze test, five of 11 heavy smokers and five of 45 non-smokers deteriorated after surgery, showing a significant difference (p = 0.018). The CBF in heavy smokers often decreased after surgery, but there was no statistically significant difference in logistic regression. Three months after surgery, the neuropsychological scores of 13 of the 15 deteriorated patients recovered to the preoperative level. Higher cortical function in heavy smokers with unruptured cerebral aneurysms often decreases transiently after operation, compared to non-smokers. Therefore, surgery planning for heavy smokers with unruptured cerebral aneurysms should consider this outcome.

Dose-related impact of alcohol consumption on cognitive function in advanced age: results of a multicenter survey

BACKGROUND

Moderate alcohol consumption has been associated in several studies with decreased risk of cardiovascular and cerebrovascular events; however, available data on the effects of alcohol intake on cognitive functioning are conflicting. We assessed the association between alcohol consumption and cognitive impairment in a series of older subjects enrolled in a multicenter pharmacoepidemiology survey.

METHODS

The association between average alcoholic intake and cognitive performance was assessed in 15,807 patients admitted to participating centers during the survey periods. Demographic variables, comorbid conditions, medications, and objective tests that were associated with cognitive impairment (as indicated by a Hodkinson Abbreviated Mental Test score <7) in separate logistical regression models were examined as potential confounders in a summary model.

RESULTS

Cognitive impairment was detected in 1693 (19%) of 8755 drinkers and 2008 (29%) of 7052 nondrinkers (Fisher's exact test, p < 0.0001). After adjusting for potential confounders, alcohol consumption was associated with decreased probability of cognitive impairment (odds ratio, 0.75; 95% confidence interval, 0.66-0.85). The relationship between drinking level and cognitive dysfunction was nonlinear, because the probability of cognitive impairment was decreased for moderate alcohol use as compared with abstinence, but it was increased for daily consumption exceeding one wine-equivalent liter among men and 0.5 liter among women. This nonlinear association persisted when cerebrovascular and Alzheimer's disease were considered separately.

CONCLUSIONS

Alcohol abuse is associated with increased prevalence of cognitive dysfunction among older subjects; however, a daily alcohol consumption of less than 40 g for women and 80 g or less for men might be associated with a decreased probability of cognitive impairment. This possible protective effect of alcohol consumption should be further assessed by prospective studies.

Screening for cognitive impairment in the older adult

Screening for cognitive impairment in the older adult is an often overlooked element of health promotion. Health care providers may assume that existing deficits will be apparent on routine medical encounters. Frequently, however, patients who are functionally impaired can present a convincing facade of normalcy. Objective screening is necessary to recognize decline. This article briefly reviews normal age-related changes in cognition and suggested screening tools as well as differential diagnoses, highlighting reversible aspects of impairment. Additionally, potential corrective measures are considered where appropriate. This evaluation will become even more significant as the geriatric population steadily increases.

Heart disease and vascular risk factors in the cognitively impaired elderly: implications for Alzheimer's dementia

The term "cardiogenic dementia" was introduced a few decades ago to indicate an alteration of consciousness and cognition due to heart disease. Although this term is now disused, the relationship between cardiovascular disease and cognitive impairment is currently of great interest, not only for its potential therapeutic implications. but also for the recently recognized important role that vascular factors appear to play in Alzheimer's disease. The aims of this review are therefore 1) to show data supporting the role of cardiac disease--namely congestive heart failure, myocardial infarction and atrial fibrillation--and other vascular risk factors--i.e., hypertension and diabetes--in the development or worsening of cognitive impairment; 2) to highlight recent observations on the relationship between presence and severity of congestive heart failure/ myocardial infarction/atrial fibrillation and Alzheimer's disease: and 3) to uncover the type of studies needed in this field in order to facilitate a more precise algorithm of dementia prevention as well as intervention in demented patients with cardiovascular disease.

Prevalence of Alzheimer's type dementia in an elderly Arab population

The aim of this study was to estimate the prevalence of dementia of the Alzheimer type (DAT) in an Arab Israeli community. Epidemiological studies of dementia have rarely been reported in Arab populations. The target population, aged 60 years or older, comprised 821 persons (362 males) who, on 1 October 1995, were residents of the rural area of Wadi Ara. These persons were examined for symptoms of dementia (DSM-IV criteria), using a semistructured questionnaire for collection of demographic and medical data. Age, gender, and education-specific prevalence rates were calculated for this population and compared to those obtained in other studies. DAT was diagnosed in 20.5% of this population. Its prevalence increased steeply with age, from 8% among those younger than 70 years to 33% among those aged 70-79 and 51% among those 80 years or older. Illiteracy was very common in this population, and strongly associated with higher prevalence of DAT (27% vs. 4%, P < 0.001). DAT was more prevalent among females than males (25% vs. 15%, P < 0.001). However, illiteracy was also significantly more frequent among women (96% vs. 42%, P < 0.001). After correction for illiteracy, the gender difference lost statistical significance. Few women smoked, but among men, the prevalence of DAT in those who smoked was lower as compared to non-smokers (14% vs. 23%, a non-significant difference). These results were confirmed by logistic regression wherein DAT was included as the dependent variable and age, illiteracy, gender and smoking as independent variables (OR=2.8, 2.8, 1.2 and 0.7, respectively; P < 0.005 for each, except for smoking). Our findings suggest that this population is unique because of extremely high rates of dementia. While the results support a protective effect of schooling against the development of dementia, other factors (e.g. genetic) must be sought to explain this high frequency.

Alcohol use and the risk of developing Alzheimer's disease

Some of the detrimental effects of heavy alcohol use on brain function are similar to those observed with Alzheimer's disease (AD). Although alcohol use may be a risk factor for AD, it is difficult to study this relationship because of similarities between alcoholic dementia and AD and because standard diagnostic criteria for alcoholic dementia have not yet been developed. Similar biological mechanisms may be involved in the effects of AD and alcohol abuse on the brain. Epidemiologic studies have investigated the relationship between alcohol use and AD but have not provided strong evidence to suggest that alcohol use influences the risk of developing AD. Further research is needed before the effect of alcohol use on AD is understood fully.