Biomedical subjects

Isabelle Carrière

Publications and source records attributed to Isabelle Carrière.

7 recordsLinked to original sources

PubMed2007

Plasma selenium over time and cognitive decline in the elderly.

BACKGROUND: Because brain oxidative stress is a cause of cognitive impairment, selenium, which is an antioxidant, may protect against cognitive decline. The aim of the study was to examine whether declining selenium levels over time are associated with cognitive decline in a cohort of community-dwelling French elderly. METHODS: During 1991-1993, 1389 subjects (age 60-71 years) were recruited into a 9-year longitudinal study with 6 waves of follow-up. Cognitive functions were evaluated by neuropsychologic tests. To take into account the entire set of cognitive measurements and the within-subject correlations between measures, we analyzed mixed linear and logistic models to study associations between selenium change and cognitive decline. RESULTS: After controlling for potential confounders, cognitive decline was associated with decreases of plasma selenium over time. Among subjects who had a decrease in their plasma selenium levels, the greater the decrease in plasma selenium, the higher the probability of cognitive decline. Among subjects who had an increase in their plasma selenium levels, cognitive decline was greater in subjects with the smallest selenium increase. There was no association between short-term (2-year) selenium change and cognitive changes. CONCLUSION: Selenium status decreases with age and may contribute to declines in neuropsychologic functions among aging people.

Age Factors↗

PubMed2006

Reliability of a new instrument for measuring maximum rising strength.

OBJECTIVE: To assess the intrarater test-retest reliability of a newly developed instrument for measuring maximum rising strength (MRS) in comparison with that of maximum knee extension strength (KES). DESIGN: Three replications of isometric MRS and KES were measured on three test occasions separated by 1 wk in 97 healthy men and women aged 23-90. MRS was measured in seated subjects using a dynamometer fixed on the ground and connected by an adjustable nonelastic cord to a padded belt. RESULTS: The intraclass coefficients (ICCs) of MRS were 0.92 and 0.93 at 60 and 70 degrees of knee flexion, respectively, and 0.98 when the mean of three highest peak values of MRS at 60 degrees and the three highest peak values at 70 degrees knee flexion on each session were considered vs. 0.95 for KES. A significant increase in MRS and KES strength was found between the first and the third sessions (+7 to 8%)(P < 0.001). No side effects of strength measurements were noticed. CONCLUSION: Despite a significant learning effect, MRS measurement is reliable in men and women of a wide range of ages. Whether this instrument will be useful for targeting individuals with early sit-to-stand difficulties requires further investigation.

Adult↗

PubMed2006

Plasma lutein and zeaxanthin and other carotenoids as modifiable risk factors for age-related maculopathy and cataract: the POLA Study.

PURPOSE: To assess the associations of plasma lutein and zeaxanthin and other carotenoids with the risk of age-related maculopathy (ARM) and cataract in the population-based Pathologies Oculaires Liées à l'Age (POLA) Study. METHODS: Retinal photographs were graded according to the international classification. ARM was defined by the presence of late ARM (neovascular ARM, geographic atrophy) and/or soft indistinct drusen (>125 microm) and/or soft distinct drusen (>125 microm) associated with pigmentary abnormalities. Cataract classification was based on a direct standardized lens examination at the slit lamp, according to Lens Opacities Classification System III. Plasma carotenoids were measured by high-performance liquid chromatography (HPLC), in 899 subjects of the cohort. RESULTS: After multivariate adjustment, the highest quintile of plasma zeaxanthin was significantly associated with reduced risk of ARM (OR=0.07; 95% CI: 0.01-0.58; P for trend=0.005), nuclear cataract (OR=0.23; 95% CI: 0.08-0.68; P for trend=0.003) and any cataract (OR=0.53; 95% CI: 0.31-0.89; P for trend=0.01). ARM was significantly associated with combined plasma lutein and zeaxanthin (OR=0.21; 95% CI: 0.05-0.79; P for trend=0.01), and tended to be associated with plasma lutein (OR=0.31; 95% CI: 0.09-1.07; P for trend=0.04), whereas cataract showed no such associations. Among other carotenoids, only beta-carotene showed a significant negative association with nuclear cataract, but not ARM. CONCLUSIONS: These results are strongly suggestive of a protective role of the xanthophylls, in particular zeaxanthin, for the protection against ARM and cataract.

Cataract↗

PubMed2005

Hierarchical components of physical frailty predicted incidence of dependency in a cohort of elderly women.

OBJECTIVE: To identify the most important predictors of early disability incidence and devise a simple score of physical frailty. METHODS: A cohort of 545 high-functioning women aged 75 years and older was followed for 7 years. Every year, the self-reported loss of at least one instrumental activity of daily living was chosen as definition of disability. An extension of the logistic regression for repeated responses, the random-effect model, was used to assess the effects of baseline predictors. The regression coefficients of the final multivariate model were scaled and rounded to create a practical score. RESULTS: The proportion of women reporting disability increased from 22.1% to 52.1% throughout the follow-up. In the multivariate model, increasing age, lower performances in mobility and balance tests, bad perceived health, lower muscle strength, higher body mass index, lower educational level, and lower reported physical activity were strong predictors of disability. Evaluating the predictive value of the simplified predictive score on an independent cohort gave a c-statistic equal to .71. CONCLUSION: The use of a powerful fitting method allows to establish a hierarchy between the components of physical frailty and to provide a predictive score with substantial practical value for clinicians and public health professionals.

Activities of Daily Living↗

PubMed2005

The three-year incidence of age-related macular degeneration: the "Pathologies Oculaires Liées à l'Age" (POLA) prospective study.

PURPOSE: To assess the 3-year incidence of age-related macular degeneration (AMD) in a French population. DESIGN: The "Pathologies Oculaires Liées à l'Age" (POLA) Study, a population-based prospective cohort study. METHODS: Retinal photographs were graded according to the international classification. Early age-related maculopathy (ARM) was defined by the presence of (1) soft indistinct drusen (>125 microm) and/or (2) soft distinct drusen (>125 microm) associated with pigmentary abnormalities. RESULTS: The 3-year incidence of AMD was 0.49% (95% confidence interval [CI]: 0.13 to 0.85) and increased significantly with age, reaching 3.41% (95% CI: 0 to 7.2) in participants aged 80 years or more. After adjustment for age, eyes with early ARM at baseline were 78 times more at risk of developing AMD than eyes without early ARM (OR = 78.4, 95% CI: 14.6 to 420.1). CONCLUSIONS: This study confirms that AMD develops mainly in subjects aged 80 years or older, and in subjects with early ARM.

Aged↗

PubMed2003

Associations of cataract with antioxidant enzymes and other risk factors: the French Age-Related Eye Diseases (POLA) Prospective Study.

PURPOSE: To determine the association of potential risk factors, including antioxidant enzymes, with the incidence of cataract. DESIGN: Cohort study. PARTICIPANTS: At baseline, the Age-Related Eye Diseases (Pathologies Oculaires Liées à l'Age, POLA) Study included 2584 residents of Sète (southern France) aged 60 years or older. From September 1998 to May 2000, a 3-year follow-up examination was performed on 1947 of the 2436 surviving participants (79.9%). METHODS: Cataract classification was based on a standardized lens examination at the slit lamp, according to Lens Opacities Classification System III. Biologic measurements were performed at baseline from fasting blood samples. MAIN OUTCOME MEASURES: At baseline and follow-up, the presence of cataract was defined as: NC or nuclear opalescence (NO) > or = 4 for nuclear cataract, C > or = 4 for cortical cataract, and P > or = 2 for posterior cataract (PSC) opacities, using opacity grades corrected for interobserver variability. Incidence rates were assessed separately for right and left eyes and for each type of cataract. RESULTS: In the multivariate model, the incidence of cortical cataract was increased in subjects with high red blood cell superoxide dismutase activity (odds ratio [OR] 4.2 [1.5-12.1], P = 0.007). The incidence of PSC cataract was increased in subjects with a high level of plasma glutathione peroxidase (OR 1.8 [1.0-3.3], P = 0.05). In addition to age, gender, and opacities at baseline, significant risk factors for incident cataract were: long-duration diabetes (OR 5.8, P = 0.001 for cortical cataract) and lifetime heavy smoking (OR 2.9, P = 0.006 for PSC cataract). CONCLUSIONS: Consistent with the baseline analysis, the results of this prospective study suggest that antioxidant enzymes might be implicated in the etiology of cataract.

Aged↗

PubMed2002

Choosing marginal or random-effects models for longitudinal binary responses: application to self-reported disability among older persons.

BACKGROUND: Longitudinal studies with binary repeated outcomes are now widespread in epidemiology. The statistical analysis of these studies presents difficulties and standard methods are inadequate. METHODS: We consider strategies for modelling binary repeated responses and focus on two specific issues: the choice between marginal and random-effects models, and the choice of the time point origin. These issues are addressed using the example of self-reported disability in older women assessed annually for 6 years. The indicator of disability "needing help to go outdoors or home-confined" is used. RESULTS: In view of the observed associations between the responses for consecutive years, the baseline response was considered as a covariate. We compared the marginal and random-effects models first when only the influence of time and age is analysed and second when individual risk factors are studied in an aetiological perspective. There were substantial differences between the parameter estimates. They were due to differences between specific concepts related to the two models and the large between-individual heterogeneity revealed by the analysis. CONCLUSIONS: A random-effects model appears to be most suitable for the analysis of self-reported disability in older women.

Activities of Daily Living↗