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Biomedical subjects

L Letenneur

Publications and source records attributed to L Letenneur.

At least 73 records · Page 4Linked to original sources
PubMed1996

Individual and environmental factors associated with infection due to Cryptococcus neoformans serotype D. French Cryptococcosis Study Group.

Differences between the two varieties of Cryptococcus neoformans with regard to geographic distribution, epidemiology, and even pathogenicity have been described. None between C. neoformans variety neoformans serotypes A and D have been reported. We reviewed 452 cases of cryptococcosis diagnosed in France, where serotype D is responsible for 21% of the infections. Univariate analysis showed that the frequency of serotype D infections was significantly higher among patients > 60 years of age, those born in Europe, those receiving corticosteroid therapy, and those who had skin lesions. In the multivariate analysis, the risk of serotype D infection was significantly higher for patients with skin lesions, those receiving corticosteroid therapy, and those living in certain regions in France. It was significantly lower for patients with meningitis those coming from Africa, and females. Among the 350 human immunodeficiency virus-infected patients, the risk was significantly higher for those > 60 years old, those who were intravenous drug abusers, and those with skin lesions. The risk was significantly lower for patients from Africa and in cases of meningitis. These results suggest that individual and environmental factors can be associated with the serotype of the infecting strain of C. neoformans.

AIDS-Related Opportunistic Infections↗
PubMed1996

Silica and aluminum in drinking water and cognitive impairment in the elderly.

We studied the relation between silica and aluminum levels in drinking water and the risk of cognitive impairment using data from a population-based survey of 3,777 French subjects age 65 years and older. We also studied the effect of pH and the concentrations of calcium, magnesium, fluorine, zinc, copper, and iron. We used a mixed effects logistic regression adjusting for age, sex, educational level, and occupation of the subjects. We confirmed the inverse relation previously found between calcium level and cognitive impairment. We found no important association between cognitive impairment and fluorine, magnesium, iron, copper, or zinc. The association between cognitive impairment and aluminum depended on the pH and the concentration of silica: high levels of aluminum appeared to have a deleterious effect when the silica concentration was low, but there was a protective effect when the pH and the silica level were high. The threshold for an aluminum effect, however, was very low (3.5 micrograms per liter) and did not support the hypothesis of a deleterious effect for only high levels of aluminum.

Aged↗
PubMed1996

Seroepidemiological study of retroviruses (HTLV-I/II, HIV-1, HIV-2) in the Department of Atacora, northern Benin.

A seroepidemiological survey to determine the prevalence of retrovirus infection (HTLV-I/II, HIV-1, HIV-2) by representative sampling of the general population in the Department of Atacora in north-western Benin is reported. The seroprevalence rate of HTLV-I in this sample was at 1.86% (95% CI 1.20-2.52%). This is in agreement with prevalence rates reported from neighbouring countries of the sub-region. No sera were found positive for HTLV-II. Seropositivity to HIV-1 was 0.3%; HIV-2 seropositivity was not encountered.

Adolescent↗
PubMed1996

Determinants of chronic bronchitis prevalence in an elderly sample from south-west of France.

This paper attempts to estimate by means of a cross-sectional study in subjects aged 65 yrs and over the determinants of the prevalence of chronic bronchitis according to age, gender, smoking history, educational level, former occupation and associated morbidity. Data were examined from the third year of a cohort (Personnes àgêes QUID (PAQUID)) and concerned 2,406 subjects. Identification of chronic bronchitis was based on a direct question asking for the presence of phlegm on most days during at least 3 months per year for at least the two previous years. Of the sample, 13% reported chronic bronchitis (20% of males, and 8% of females). A multivariate analysis was performed and showed that chronic bronchitis was linked to sex, smoking history and professional category. Independent of these factors, asthma history and digitalic drug therapy were also closely associated to chronic bronchitis. These results underline the long-term effect of smoking and occupation on chronic bronchitis, and also illustrate the strong association with asthma and cardiac morbidity over 65 yrs of age.

Age Factors↗
PubMed1995

Visuo-spatial attention and psychomotor performance in elderly community residents: effects of age, gender, and education.

In cross-sectional analysis of 1,799 subjects of the Paquid Research Program, an epidemiological study on brain aging conducted in the Bordeaux area (France), we have studied the effects of age, gender, and education level on psychometric tests requiring visuo-spatial focused attention and psychomotor performance. Although previous studies suggest that normal aging produces no significant change in focused attention, we did observe lower attentional abilities and lower speed of execution with increasing age. Female gender and low education level were also related to poorer attention and psychomotor performance. As the effects of these individual factors are difficult to disentangle from each other on the small samples of subjects used in group studies, epidemiological surveys seem useful to provide a better understanding of the neuropsychology of aging.

Age Factors↗
PubMed1995

The PAQUID survey and correlates of subclinical hypothyroidism in elderly community residents in the southwest of France.

The aim of this study was to assess the prevalence of increased thyroid-stimulating hormone (TSH) levels (subclinical or undiagnosed hypothyroidism) in a representative sample of a community-living elderly population and to examine the relationships with cognitive functions and depressive symptoms. An epidemiological study was made of a cohort of 2792 subjects over 65 years of age. A blood sample was obtained from 425 volunteers of this cohort and assayed for TSH. Every subject participating in the study was interviewed and given a battery of neuropsychological tests by a psychologist. Three hundred and eighty-one subjects (89.7%) had normal TSH levels; 18 subjects (4.2%) had TSH lower than 0.4 microU/ml, associated in two of them with hyperthyroxinaemia. Twenty-six subjects (6.1%) had increased TSH levels, associated in 18 of them with a normal free thyroxine level and in eight with a low free thyroxine level. Increased TSH levels were significantly linked with female sex and with the presence of symptoms of depression on the CES-D scale but not with impairment of cognitive function.

Aged↗
PubMed1995

Social and leisure activities and risk of dementia: a prospective longitudinal study.

OBJECTIVE: To study the relationship between social and leisure activities and risk of subsequent dementia in older community residents. SETTING: A cohort study of people aged 65 and older were followed-up 1 and 3 years after a baseline screening (the Paquid study). PARTICIPANTS: 2040 older subjects living at home in Gironde (France) were randomly selected and followed for at least 3 years. DATA COLLECTION: Information about social and leisure activities was collected during the baseline screening with an interview by a psychologist. Incident cases of dementia were detected during the first and third year follow-up screenings according to the DSM-III-R criteria. MAIN RESULTS: All but one of the social and leisure activities noted were significantly associated with a lower risk of dementia. Only golden club participation was not significantly associated with this risk. After adjustment for age and cognitive performance measured by the Mini-Mental State Exam, visual memory test, and verbal fluency test, only traveling (Relative risk (RR) = .48,95% Confidence Interval (95% CI) = .24-.94), odd jobs or knitting (RR = .46,95% CI = .26-.85), and gardening (RR = .53, 95% CI = .28-.99) remained significant. CONCLUSIONS: Regular participation in social or leisure activities such as traveling, odd jobs, knitting, or gardening were associated with a lower risk of subsequent dementia.

Aged↗
PubMed1995

Dementia in Parkinson's disease: a population-based study in ambulatory and institutionalized individuals.

We examined the frequency of dementia and depressive symptomatology in 60 Parkinson's disease (PD) patients, identified in a large representative sample of the population, aged 65 years and older, living at home or in institutions in Gironde, France. Dementia, diagnosed according to DSM-III-R criteria, was present in 17.6%, and depressive symptomatology, assessed by the Center for Epidemiologic Studies-Depression Scale, was present in 32.7%. The frequency of dementia in PD increased strongly with age and was higher in institutionalized PD patients than in those living at home. PD was significantly associated with dementia for individuals living at home (odds ratio = 8.2, adjusted for age and symptoms of depression.

Aged↗
PubMed1995

Score test for familial aggregation in probands studies: application to Alzheimer's disease.

When studying familial aggregation of a disease, the following two-stage design is often used: first select index subjects (cases and controls); then record data on their relatives. The likelihood corresponding to this design is derived and a score test of homogeneity is proposed for testing the hypothesis of no-aggregation. This test takes into account the selection procedure and allows adjustment to be made for explanatory variables. It appears as the sum of three terms: a pure test of homogeneity, a test of comparison of observed minus expected cases in the two groups, and a term which adjusts for the possible unequal probabilities of disease of the index subjects. Asymptotic efficiency and a simulation study show that the proposed test is superior to either the pure homogeneity test or tests based on the comparison of numbers of affected in the two groups. The test statistic, which has an asymptotically standard normal distribution, is applied to a study of familial aggregation of early-onset Alzheimer's disease for which a highly significant value (9.46) is obtained: this is the highest value among the three tests compared, in agreement with the simulation study. A logistic normal model is fitted to the data, taking account of the selection procedure: it allows to estimate the regression parameters and the variance of the random effect; the likelihood ratio test for familial aggregation seems less powerful than the score test.

Alzheimer Disease↗
PubMed1994

Components of drinking water and risk of cognitive impairment in the elderly.

The relation between aluminum, fluorine, calcium, and pH in drinking water and the risk for cognitive impairment was studied using data collected in 1988-1989 in a population-based survey of 3,777 French men and women aged 65 years and older (the Paquid study). Cognitive impairment was defined as a score lower than 24 on the Mini-Mental State Examination. Data related to drinking water came from two prospective measurement surveys whose reliability was checked by a variability study. A mixed effects logistic regression was performed, adjusting for the effects of the age, sex, educational level, and occupation of the participants. A significant protective effect was found for high calcium concentration (odds ratio = 0.8 for a concentration > or = 75 mg vs. < 75 mg, p = 0.015). For aluminum, no significant effect was found when pH was not included in the model, but the results showed a weak interaction between aluminum and pH. When the four variables (calcium, aluminum, pH, and aluminum x pH interaction) were considered in the statistical analysis as a group, this group was significantly related to cognitive impairment (p = 0.01).

Aged↗
PubMed1994

Tobacco consumption and cognitive impairment in elderly people. A population-based study.

We examined the relationship between tobacco consumption and Alzheimer's disease (AD), cognitive deficit, and memory performances in elderly community residents of southwestern France. Subjects were considered to have a cognitive deficit if they scored under 24 on the French version of the Mini-Mental State Examination, and poor memory performances if they scored under 8 on the Benton Visual Retention Test. Among the 3770 subjects who gave information about their smoking habits, only 356 (9.5%) were current smokers, 998 (26.5%) were past smokers, and 2416 (64%) were never smokers. Current smokers (odds ratio (OR) = 0.52, P < 0.001) and past smokers (OR = 0.54, P < 0.001) had a lower risk of cognitive deficit than did never smokers. However, this significant relationship disappeared after adjustment for potential confounding factors such as occupational category (OR = 0.91 (not significant) for current smokers and OR = 0.87 (not significant) for past smokers). Similar results were obtained for the risk of AD and of poor memory performances. The apparent protective effect of smoking habits on cognitive abilities could be due to a confounding effect of occupational category.

Aged↗
PubMed1994

Incidence of dementia and Alzheimer's disease in elderly community residents of south-western France.

BACKGROUND: Dementia is a growing problem in developed countries. The aim of this paper is to estimate incidence rates of dementia, Alzheimer's disease and vascular dementia in a community population of South-Western France. METHODS: A sample of 2792 subjects was selected and followed-up 1 year and 3 after the initial screening. At each visit, a standardized questionnaire was administered by trained psychologists. Demented subjects were identified using a two-step procedure. The first step consisted of a systematic screening by the psychologist using DSM IIIR criteria for dementia. In the second step, subjects who fulfilled the DSM IIIR criteria were examined by a neurologist. NINCDS-ADRDA criteria were applied to diagnose Alzheimer's disease. RESULTS: Incidences of dementia and Alzheimer's disease were estimated at 16.3 and 11.4 per 1000 per year, respectively. Incidence estimates increased with age from 2 per 1000 in subjects aged 65-69 years to 74 per 1000 in subjects > 90 years. Incidence estimates of Alzheimer's disease showed the same increased from 0.7 per 1000 to 66 per 1000. Incidences of dementia and of Alzheimer's disease did not level off with age and were not different between genders.

Aged↗
PubMed1994

Self-reported memory complaints and memory performance in elderly French community residents: results of the PAQUID Research Program.

An epidemiological survey of self-reported memory complaints and memory performance [assessed with Benton's visual-retention test (BVRT) and the Wechsler paired-associates test (WPAT)] was undertaken in a community sample of 2,726 noninstitutionalized subjects aged 65 and over living in Gironde (southwestern France). A significant relationship was observed between the presence of self-reported memory problems and lower performance on the BVRT and the WPAT. However, beyond this relationship, there was significant discordance between the two evaluations, explained in part by the fact that the correlates of memory functioning were not related with similar strength to self reports and to actual performance. In general, females and subjects who scored above the depressive symptomatology threshold reported more problems, while lower performances were related to older age and low educational level. The discordance between self reports and actual performance may suggest anosognosia of mild memory deficits and could possibly be a predictor of future intellectual deterioration.

Aged↗
PubMed1994

Dementia-free life expectancy in France.

OBJECTIVES: Increasing concern with the quality of gains in life years has led to the development of a new synthetic indicator of population health:health expectancy. Until now, calculations have been made for physical disabilities only. A first estimate of mental health expectancy is presented: dementia-free life expectancy. METHODS: Sullivan's method was used to calculate dementia-free life expectancy for a random representative sample of 4134 persons over 65 years of age in the Bordeaux region of France. The diagnosis of senile dementia was made in two stages, based on Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R) criteria. RESULTS: At 65 years of age, a person's dementia-free life expectancy is 16.9 years within a total life-expectancy of 17.7 years; it decreases with age in parallel with the decrease in total life expectancy so that life expectancy with dementia stays constant at 0.8 years. Although dementia prevalence increases with age, if the prevalence is adjusted for mortality, the largest number of persons with dementia are in their early eighties. At each age women have a higher dementia-free life expectancy. CONCLUSIONS: Trends in dementia-free life expectancy are similar to those found in disability-free life expectancy. Because the dementia prevalence rates used in this estimate resemble a general model derived from meta-analysis, it can be assumed that similar results will be found in other Western countries with similar mortality rates.

Aged↗
PubMed1994

Test of homogeneity of binary data with explanatory variables.

Apparent heterogeneity of the risk of a disease in different groups may be explained by subject-specific risk factors unequally distributed in these groups. We propose a score test of homogeneity that allows adjustment for known risk factors of the disease. The test is based on a random-effect logistic regression model and requires only simple computations in addition to a conventional logistic regression method. The score test is applied to the study of geographical heterogeneity of cognitive impairment in elderly using a sample of 3,318 subjects scattered in 75 parishes. It is shown that an apparent heterogeneity disappears when taking into account subject-specific risk factors. This test may also be useful for studying familial aggregation of a disease.

Epidemiologic Methods↗