PubMed Health⌕ Search

Biomedical subjects

Karen Ritchie

Publications and source records attributed to Karen Ritchie.

At least 19 recordsLinked to original sources
PubMed2006

New insight into the association of apolipoprotein E genetic variants with carotid plaques and intima-media thickness.

BACKGROUND AND PURPOSE: Carotid plaques and elevated carotid artery intima-media thickness (IMT) are major predictors of vascular morbidity and mortality. Our aim was to test their association with 2 polymorphisms of the apolipoprotein E (apoE) gene, epsilon and -219G/T. METHODS: The study was performed on 5856 subjects aged > or =65 years recruited from the French population for the Three-City Study. Carotid ultrasound examination included an assessment of atherosclerotic plaques in the extracranial carotid arteries and a measurement of IMT in the common carotid arteries (CCA) at a site free of plaques. The genetic association was tested using genotype and haplotype analyses. RESULTS: In a multivariate analysis including both polymorphisms and vascular risk factors, carotid plaques were more frequent in epsilon4 homozygotes (adjusted odds ratio=2.12, 95% CI=1.27 to 3.53) and less frequent in epsilon2 carriers (adjusted odds ratio=0.79, 95% CI=0.66 to 0.95) compared with epsilon3 homozygotes. Adjusting for and stratifying on lipid levels did not modify these results. CCA-IMT was higher in carriers of the epsilon34 genotype (mean CCA-IMT=0.744 mm versus 0.732 mm for the epsilon33 genotype, P=0.002), but the association disappeared after excluding subjects with carotid plaques. No association was found between the -219 polymorphism and either carotid plaques or CCA-IMT, and there was no interaction or cis-effect between -219 and epsilon. CONCLUSIONS: This study, conducted on a large population cohort of French elderly, demonstrated that carotid plaques were significantly associated with the apoE epsilon polymorphism independently of the -219 polymorphism and vascular risk factors, in particular lipid levels.

Aged↗
PubMed2006

Revised criteria for mild cognitive impairment: validation within a longitudinal population study.

BACKGROUND: Mild cognitive impairment (MCI) refers to the transitional zone between normal ageing and dementia. Current criteria perform poorly within the general population setting. Revisions have been proposed based on results obtained from clinical and epidemiological studies. OBJECTIVE: To evaluate revised diagnostic criteria for mild cognitive impairment (MCI-R) incorporating changes in activity level and non-mnesic cognitive functioning. METHOD: MCI-R subjects were recruited from a representative network of general practitioners in the south of France. A computerized neuropsychometric examination was given. At 2 years of follow-up, a diagnosis of dementia was made by a neurologist using DSM-IIIR criteria and without knowledge of the results of the cognitive testing. Rates of conversion to incident dementia were assessed by receiver operating characteristics analysis. RESULTS: The MCI-R prevalence was found to be 16.6% using revised criteria. A significantly better prediction of transition to dementia (AUC = 0.80, sensitivity: 95%, specificity: 66%) was obtained with MCI-R than with the previous MCI criteria (AUC = 0.48, sensitivity: 5%, specificity: 91%). The predictive power was found to increase when MCI subtypes were combined. CONCLUSION: Incorporating the possibility of change in activity level and alteration of non-mnesic cognitive functions have been found to ameliorate the original algorithm and better define subjects converting to dementia. This definition may be applicable to both clinical and population research.

Aged↗
PubMed2006

Mild cognitive impairment.

Mild cognitive impairment is a syndrome defined as cognitive decline greater than expected for an individual's age and education level but that does not interfere notably with activities of daily life. Prevalence in population-based epidemiological studies ranges from 3% to 19% in adults older than 65 years. Some people with mild cognitive impairment seem to remain stable or return to normal over time, but more than half progress to dementia within 5 years. Mild cognitive impairment can thus be regarded as a risk state for dementia, and its identification could lead to secondary prevention by controlling risk factors such as systolic hypertension. The amnestic subtype of mild cognitive impairment has a high risk of progression to Alzheimer's disease, and it could constitute a prodromal stage of this disorder. Other definitions and subtypes of mild cognitive impairment need to be studied as potential prodromes of Alzheimer's disease and other types of dementia.

Aged↗
PubMed2006

IPA survey of brief cognitive screening instruments.

BACKGROUND AND OBJECTIVES: Cognitive screening is a "first step" in detecting dementia and other neuropsychiatric syndromes and hence represents an important public health and clinical initiative. A plethora of cognitive screening instruments has been advocated in recent years, but the extent to which these instruments are used or their effectiveness is not well known. An International Psychogeriatric Association (IPA) survey was designed to determine which cognitive screening instruments were used most frequently by clinicians with special expertise in the neuropsychiatric aspects of old age and also to determine the ones considered most useful by these specialists. METHOD: Under the auspices of the IPA, the survey was mailed in the fall of 2004 to all IPA members as well as members of the American and Canadian Associations of Geriatric Psychiatry. The survey inquired about demographic information, the frequency of use of cognitive screening instruments, and the value attributed to the cognitive screening instruments. Participants also had an opportunity to provide written commentary. RESULTS: A total of 334 completed surveys were processed. The majority of respondents were geriatric psychiatrists (58%). Of the 20 different instruments that were listed on the survey, only six were selected as "routinely" or "often used" by the survey respondents. These instruments in declining order were: (1) the Folstein Mini-mental State Examination; (2) the Clock Drawing Test; (3) Delayed Word Recall; (4) the Verbal Fluency Test; (5) Similarities; and (6) the Trail Making Test. "Effectiveness" and "ease of administration" were the test characteristics most highly predictive of frequency of use. Open-ended comments highlighted patient factors that continue to provide challenges, including ethnicity/culture, language, education/literacy, and sensory impairment. Respondents concluded that "no single test is adequate." CONCLUSIONS: Psychogeriatricians worldwide routinely use a relatively small number of brief cognitive screening instruments. Further evaluation is necessary as the need increases for cognitive screening guidelines that inform public health initiatives related to dementia and neuropsychiatric syndromes.

Adult↗
PubMed2006

Non-degenerative mild cognitive impairment in elderly people and use of anticholinergic drugs: longitudinal cohort study.

OBJECTIVE: To assess the potential of anticholinergic drugs as a cause of non-degenerative mild cognitive impairment in elderly people. DESIGN: Longitudinal cohort study. SETTING: 63 randomly selected general practices in the Montpellier region of southern France. PARTICIPANTS: 372 people aged > 60 years without dementia at recruitment. MAIN OUTCOME MEASURES: Anticholinergic burden from drug use, cognitive examination, and neurological assessment. RESULTS: 9.2% of subjects continuously used anticholinergic drugs during the year before cognitive assessment. Compared with non-users, they had poorer performance on reaction time, attention, delayed non-verbal memory, narrative recall, visuospatial construction, and language tasks but not on tasks of reasoning, immediate and delayed recall of wordlists, and implicit memory. Eighty per cent of the continuous users were classified as having mild cognitive impairment compared with 35% of non-users, and anticholinergic drug use was a strong predictor of mild cognitive impairment (odds ratio 5.12, P = 0.001). No difference was found between users and non-users in risk of developing dementia at follow-up after eight years. CONCLUSIONS: Elderly people taking anticholinergic drugs had significant deficits in cognitive functioning and were highly likely to be classified as mildly cognitively impaired, although not at increased risk for dementia. Doctors should assess current use of anticholinergic drugs in elderly people with mild cognitive impairment before considering administration of acetylcholinesterase inhibitors.

Aged↗
PubMed2006

Functional Vitamin E deficiency in ApoE4 patients with Alzheimer's disease.

Oxidative stress has been implicated in the development of Alzheimer's disease (AD). Consequently, antioxidant therapies including Vitamin E (VitE) supplementation for both prevention and treatment of neurodegenerative diseases currently appears to be a promising avenue of research. The aim of the present study was to examine the relationship between AD and the ApoE phenotype, lipid parameters and VitE levels in a large cohort of elderly subjects. No absolute deficit was observed in plasma VitE levels. However in AD, ApoE4 is not associated with an increase in total cholesterol (TC) and VitE levels. Moreover, our results suggest that oxidative stress-induced injury and protection by VitE in AD are related to the ApoE phenotype. Our study strongly supports the hypothesis of an impairment of lipophilic antioxidant delivery to neuronal cells in AD leading to a tissular antioxidant deficiency which could facilitate oxidative stress.

Aged↗
PubMed2006

Prevalence, awareness, treatment, and control of hypertension in the elderly: the Three City study.

OBJECTIVE: To study management of hypertension in the elderly in a large population-based study and to evaluate the prevalence of hypertension and factors related to awareness, treatment, and control. DESIGN: The Three City study, a population-based study among 9693 non-institutionalized individuals aged 65 years and over. METHODS: Blood pressure was measured with an automated electronic device, and treatment assessed, during home interview. Hypertension was defined by a mean blood pressure of two measurements superior to or equal to 160/95 mmHg and/or the intake of antihypertensive medications. RESULTS: In the final working sample of 9090 people, 62% were hypertensive. More than two-thirds were aware of their hypertension and 81% were treated with antihypertensive drugs. Among 4573 treated hypertensive participants, 35% had a blood pressure over 160/95 mmHg and 69% over 140/90 mmHg. Women were more frequently aware of their hypertension, more frequently treated, and more frequently controlled than men. A history of cardiovascular disease, high body mass index, diabetes and high frequency of visits to the general practitioner were related to higher percentages of awareness and treatment. Among treated hypertensive patients, those with a history of cardiovascular events or who visited their general practitioner more often or who more often had their blood pressure measured were more frequently controlled. Awareness was strongly associated with treatment, but was inversely related to control of hypertension among treated hypertensive patients. CONCLUSIONS: Management of hypertension, and particularly its control among treated hypertensive patients, needs to be improved in people aged 65 years and over.

Aged↗
PubMed2006

'I think therefore I am': improving cognition.

PURPOSE OF REVIEW: In the absence of a specific treatment for dementia, the effective management of cognitive symptoms is a clinical priority. RECENT FINDINGS: Although some differences have been observed in the profile of cognitive complaints observed in subtypes of dementia, there is increasing recognition of common, interacting neurobiological causes suggesting the need to seek a common treatment applicable to all causes of cognitive deterioration. There also exists increasing interest in intervening at the level of minor cognitive dysfunction by reducing risk factors for subclinical states. SUMMARY: Pharmacological treatment of cognitive disorder is beneficial but has only temporary benefit for a subgroup of patients. Pharmacogenetics may have an important future role to play in deciding which patients may best benefit from the treatment. Low side effect therapies such as cognitive therapy and acupuncture show some benefits but their utility in combination with pharmacotherapies remains to be demonstrated. Prevention of milder forms of cognitive disorder by controlling risk factors such as hypertension and diabetes may reduce rates of more severe cognitive degeneration. Persons with cognitive dysfunction are commonly excluded from making decisions about the implementation of cognition-enhancing treatments although they wish to do so.

Cognition↗
PubMed2005

Sleep and depression.

BACKGROUND: Of all the psychiatric disorders associated with insomnia, depression is the most common. It has been estimated that 90% of patients with depression complain about sleep quality. Since the first reports of short rapid eye movement (REM) latency in depressed patients and of the effect of sleep deprivation on depression in the 1970s, numerous sleep studies have provided extensive observations and theoretical hypotheses concerning the etiology and pathophysiology of depression. The aim of this review is to summarize knowledge regarding the relationships between sleep and depression. DATA SOURCES AND SELECTION: MEDLINE and PsycINFO searches of the literature published in English or French between 1964 and 2005 that examined the relationships between sleep disturbance and depression were conducted. Search terms used were depression, depressive disorder, affective disorder, mood disorders, seasonal affective disorder, sleep, sleep disorders, insomnia, REM, polysomnography, sleep deprivation, electroencephalography, PET, SPECT, and fMRI. DATA SYNTHESIS: Two hundred five papers were identified and selected and then integrated into the following categories: sleep architecture, antidepressive therapies, age- and gender-associated differences, functional imaging results, and sleep-related hypotheses explaining the pathophysiology of depression. CONCLUSION: Numerous studies provide findings indicating the remarkable relationship between sleep alterations and depression. Although the existing hypotheses are not likely to explain all aspects of the sleep alterations in depression, each may be worth being maintained for refinements of pathophysiologic models of depression as new data accumulate. Further research taking into account the heterogeneity of depressive disorder and linking the different areas of research is needed to develop more comprehensive theoretical models and new therapies for depression.

Adrenocorticotropic Hormone↗
PubMed2004

Alcohol consumption and carotid artery structure in older French adults: the Three-City Study.

BACKGROUND AND PURPOSE: Several epidemiological studies have suggested a U-shaped association between alcohol consumption and cardiovascular risk. However, the modifications of vascular structure associated with alcohol consumption are largely unknown. METHODS: The study population sample comprised 6216 subjects (3780 women and 2436 men) aged 65 years or older who were recruited from 3 French cities (Bordeaux, Dijon, and Montpellier, which are located in the 3 principal wine-growing regions). Usual alcohol consumption was assessed by a standardized questionnaire. Carotid ultrasound examination included measurements (at sites free of plaques) of intima-media thickness (IMT) at the common carotid arteries (CCA), CCA-lumen diameter, and assessment of atherosclerotic plaques in the extracranial carotid arteries. RESULTS: Neither CCA-IMT nor carotid plaques were associated with alcohol consumption categories in the overall population. Weak and marginal positive associations were observed between categories of alcohol consumption and carotid plaques in men (P=0.02 for linear trend). CCA-lumen diameter was positively and independently associated with alcohol consumption in overall population and in men and in women. Similar results were found between alcohol consumption and carotid measurements in subjects free of cardiovascular disease (90.1% of the population). CONCLUSIONS: This very large population sample of French older adults shows no marked relationships of alcohol consumption with atherosclerosis. The positive association of alcohol intake with carotid arterial diameter may reflect the ability of alcohol to maintain adaptive enlargement to preserve lumen area.

Aged↗
PubMed2004

Contingent screening for Down syndrome is an efficient alternative to non-disclosure sequential screening.

OBJECTIVE: To present a first and second trimester Down syndrome screening strategy, whereby second-trimester marker determination is contingent on the first-trimester results. Unlike non-disclosure sequential screening ('the Integrated test'), which requires all women to have markers in both trimesters, this allows a large proportion of the women to complete screening in the first trimester. METHODS: Two first-trimester risk cut-offs defined three types of results: positive and referred for early diagnosis; negative with screening complete; and intermediate, needing second-trimester markers. Multivariate Gaussian modelling with Monte Carlo simulation was used to estimate the false-positive rate for a fixed 85% detection rate. The false-positive rate was evaluated for various early detection rates and early test completion rates. Model parameters were taken from the SURUSS trial. RESULTS: Completion of screening in the first trimester for 75% of women resulted in a 30% early detection rate and a 55% second trimester detected rate (net 85%) with a false-positive rate only 0.1% above that achievable by the Integrated test. The screen-positive rate was 0.1% in the first trimester and 4.7% for those continuing to be tested in the second trimester. If the early detection rate were to be increased to 45% or the early completion rate were to be increased to 80%, there would be a further 0.1% increase in the false-positive rate. CONCLUSION: Contingent screening can achieve results comparable with the Integrated test but with earlier completion of screening for most women. Both strategies need to be evaluated in large-scale prospective studies particularly in relation to psychological impact and practicability.

Biomarkers↗
PubMed2004

Is deafness a disease of poverty? The association between socio-economic deprivation and congenital hearing impairment.

An association between congenital hearing impairment and deprivation has been suggested, but evidence is limited. We studied children born in Greater Glasgow, 1985-94, with bilateral congenital hearing impairment. The children were divided into seven deprivation categories using the Carstairs Deprivation Index. One hundred and twenty-four hearing-impaired children were born over the study period, an incidence of 1.18/1000 live births. There was a clear association between deprivation category and incidence, ranging from 0.47/1000 to 1.72/1000. An association with deprivation was seen for children with a family history and perinatal problems (such as prematurity and low birth weight). No association was found for other aetiological groups such as craniofacial syndromes or early postnatal infection. Deprivation had no effect on age of diagnosis or hearing aid provision. Deprivation is associated with congenital hearing impairment, due to more prematurity and low birth weight in deprived families, and the fact that families with many hearing-impaired members are economically disadvantaged. There should be a strong emphasis on the needs of the socio-economically disadvantaged when planning services for hearing-impaired children.

Deafness↗
PubMed2003

Consumption of psychotropic medication in the elderly: a re-evaluation of its effect on cognitive performance.

BACKGROUND: There have been few general population studies of the effects of psychotropic treatment on cognitive functioning in the elderly. Current evidence based on studies with numerous procedural shortenings supports the notion of the detrimental effect. OBJECTIVES: To examine changes in a wide range of specific cognitive abilities across time in a general population sample in order to establish a relationship between psychotropic drug use and cognitive performance, and to estimate to what extent such cognitive changes may be attributable to psychotropic use or other factors, notably age and co-morbidity. METHOD: We analysed the data from the Eugeria longitudinal study of cerebral ageing. Three hundred and seventy two subjects (263 female and 109 male) were visited at their place of residence and given a computerized cognitive examination. Depressive symptomatology and depressive episodes were defined according to ICD-9 criterias and medication use were established. Four categories of psychotropic consumers was differentiated. Using a logistic regression model, comparisons were made between consumers and non-consumers. RESULTS: A significant positive effect in chronic consumers was found on tests of secondary memory (delayed verbal recall: Odds Ratio (OR)=1.22; 95% Confidence Intervals (CI) [1.04-1.43]; p=0.013) and this effect is principally attributable to antidepressants with significant effects being shown for both verbal (OR=1.59; 95%CI [1.18-2.14]; p=0.002) and visual recall (OR=1.51; 95%CI [1.05-2.16]; p=0.025). No effect is found for benzodiazepines. CONCLUSIONS: Contrary to the common belief that psychotropic drug use has a detrimental effect on cognitive function of elderly people, even long term use is seen to be benign. We attest to the positive effects of antidepressant therapy on secondary memory.

Aged↗
PubMed2002

The dementias.

Dementia affects about 5% of the elderly population over age 65 years and has an unexplained predominance in women and a low rate in some cultures. Different forms of dementia are now distinguished-Alzheimer's disease, dementia with Lewy bodies, frontotemporal dementia, and dementia secondary to disease, such as AIDS dementia. However, such nosological boundaries are being re-evaluated because different dementias are believed to have common underlying neuropathology. Neurochemical and neurobiological research has led to advances in understanding causes of dementia, and functional imaging has allowed identification of possible biomarkers; from these, a range of potential treatment approaches have arisen that focus on enhancement of neurotransmitter function, intervention at the level of amyloid production and deposition, and reduction of secondary risk factors such as hypertension, depression, and hypolipidaemia. Molecular diagnostic testing and genetic counselling for families with autosomal dominant early-onset dementia are new developments; however, this approach is not useful for late-onset dementia, in which the identified candidate susceptibility genes have a relatively small effect on risk. While fundamental research works towards new biological treatment strategies, much remains to be done in the area of disease management and the development of appropriate models of long-term care.

Age Distribution↗
PubMed2002

Mild extrapyramidal signs and functional impairment in ageing.

BACKGROUND: Little is known about the clinical significance of mild extrapyramidal signs (EPS) in elderly individuals. We investigated whether EPS are associated with functional impairment in older people with cognitive decline. METHODS: A sub-group of 105 participants from the EUGERIA Study of Cognitive Ageing without Parkinson's disease or dementia, but with informant evidence of cognitive decline, were followed across three years and underwent neurological examination and assessment of mental health, cognition and functional capacity. RESULTS: 28.6% had at least one EPS (resting tremor, muscular rigidity or akinesia, of which rigidity was the most frequent). EPS presence was significantly associated with functional impairment after controlling for age and cognitive impairment (AAMI), although the association was reduced to borderline significance after further adjustment for depression and psychotropic medication use. There was evidence of colinearity between EPS and depression, possibly suggesting similar underlying mechanisms. CONCLUSIONS: There is an association between mild EPS and functional impairment in older persons with evidence of cognitive decline, but free of dementia or Parkinson's disease.

Activities of Daily Living↗