SMOKING , ALCOHOL CONSUMPTION AND DEMENTIA IN PERSONS OVER THE AGE OF 65 FROM THE CITY OF VARNA , BULGARIA

SUMMARY Findings about the possible relation between smoking and dementia are ambiguous. Earlier research is dominated by the statement that smoking is a protective factor for Alzheimer’s disease while later reports affirm that it could increase the risk for AD, and cessation could lower it to a certain degree. Some studies fail to establish an association between smoking and dementia or AD. The role of alcohol consumption as a risk factor for these disorders is also subject to discussion. Smoking, alcohol consumption and their possible relationships with dementia in persons over the age of 65 were assessed in the framework of a dementia prevalence study in the city of Varna, Bulgaria. No statistically significant correlations were found between the diagnosis of dementia, Alzheimer’s disease, vascular dementia, MCI, and the above-mentioned risk factors. This corresponds to the ambiguous data in the literature, where no clear statement exists whether smoking and alcohol consumption could be regarded as risk factors for dementing disorders or not.


Mechanisms of dementia initiation and development
are not yet completely understood.Risk factor analysis is one of the methods used to clarify them.Advanced age, female sex, low education, genetic and other factors are among the most frequently discussed (1,5,7).
Findings about the possible relation between smoking and dementia are ambiguous.Earlier research is dominated by the statement that smoking is a protective factor for Alzheimer's disease (AD).This could be explained by the positive effect of nicotine on cholinergic neurotransmission, leading to better performance on some cognitive tests.Later reports however affirm that such results could be influenced by study design and sample selection issues (3).On the other hand, some authors admit that smoking could increase the risk for AD, while cessation could lower it to a certain degree (9).AD patients who smoke at the initial stages of the disease may be endangered by an atypical clinical progression with earlier death (12).Smoking could also accelerate cognitive decline in nondemented adults (10).Other studies fail to establish an association between smoking and dementia or AD (14).
While alcohol consumption is regarded by some investigators as a possible risk factor for cognitive impairment and dementia, others deny the relationship or discuss that it could depend on the quantity and type of alcohol consumed (6,11).Some authors point out that small to moderate amounts of alcohol could have a protective effect (8,13).ApoE e4 allele carriers could also be at increased risk for dementia if consuming alcohol (2).

PURPOSE
The purpose of the current work is to assess smoking, alcohol consumption, and their relationships with dementia in a random sample of urban population within the framework of the first study of dementia in Bulgaria.

SUBJECTS AND METHODS
A two-phase, cross-sectional study was performed in the city of Varna, Bulgaria.A community based random sample of 605 subjects over the age of 65 was selected for participation.Informed consent was signed by 540 subjects, who were then included in the study, while non-responders were 65 (Table 1).

Journal of IMAB -Annual Proceeding (Scientific Papers) 2009, book 1
All responders who screened positive for cognitive impairment were subject to a detailed clinical, neuropsychological and imaging assessment.They were then classified as having dementia (and its subtypes), mild cognitive impairment (MCI) or no cognitive impairment, according to respective consensus criteria (4).
Relationships between risk factors and final diagnosis were assessed using non-parametric correlation analysis.

Fig. 1. Distribution of MCI and dementia types in the population
Fig. 2. Distribution of subjects according to smoking status and sex Three hundred and sixty-one persons (66.9%) answered that they have never smoked; 139 (25.7%), that they have smoked regularly, but have stopped more than 6 months ago; 39 (7.2%), that they smoked currently or have stopped less than 6 months ago.One person (0.2%) provided no answer.Non-smokers were generally women, while most current or ex-smokers were men (Fig. 2).Cigarettes were the only product reported, while no cigar or pipe smokers were identified.
Eighty-nine subjects (16.5%) answered that they lived or had lived with smokers and 63 (11.7%) that they worked or had worked with smokers.

Fig. 3. Distribution of subjects according to alcohol consumption and sex
Additional questions specifying type of beverage and drinking frequency were asked.Seventy-five subjects (13.9%) reported everyday use of spirits, 25 (4.6%) of beer, 39 (7.2%) of wine (Fig. 4).Reported quantities are shown in Table 2.

Fig. 4. Everyday consumption of alcohol (by types)
Kendall's analysis showed no statistically significant correlations between the diagnosis of dementia, AD, vascular dementia (VaD), or MCI, and the assessed risk factors, smoking and alcohol consumption (Tables 3, 4).

DISCUSSION
Though the present study does not fully comply with the classical design for assessment of risk factors and acquisition of representative data for their influence on the whole population, the gathered information permits the implementation of analyses concerning the specific sample.In this regard, our results are not unexpected for an aged urban Bulgarian population.Most subjects are currently non-smokers, and stratifying the data by sex underlines the high relative share of non-smoking women and smoking men.A small part of all subjects use alcohol on an everyday basis and the share of those consuming larger quantities is minimal.The most frequent use of spirits is not surprising, nor is the trend towards more evident reduction than increase of consumption.It is worth mentioning that in some cases alcohol consumption is ceased because of health issues.Two hundred and nine subjects reported no recent change in drinking habits, 86 answered that they had reduced alcohol consumption, 10 had increased it, while 26 had stopped drinking (Fig. 5).Health problems were the main reason for stopping in 21 of the cases.

Table 1 .
Study sample by age and sex. SMOKING,