Leigh Johnson

Serum Brain-Derived Neurotrophic Factor Levels Are Specifically Associated with Memory Performance among Alzheimer’s Disease Cases

Aims: Our purpose was to study the link between serum brain-derived neurotrophic factor (BDNF) levels and neuropsychological functioning through the Texas Alzheimer’s Research Consortium cohort. Methods: A total of 399 participants [probable Alzheimer’s disease (AD) n = 198, controls n = 201] were available for analysis. The BDNF levels were assayed via multiplex immunoassay. Regression analyses were utilized to examine the relation between BDNF levels and neuropsychological functioning. Results: There were no significant mean differences in BDNF levels between cases and controls. In the AD group, the BDNF levels were significantly negatively associated with the scores on immediate [B = –0.07 (0.02), t = –3.55, p = 0.001] and delayed [B = –0.05 (0.02), t = –2.79, p = 0.01] verbal memory and immediate [B = –0.12 (0.05), t = –2.70, p = 0.01] visual memory. No other neuropsychological variables were significantly related to the BDNF levels. The BDNF levels were not significantly related to the neuropsychological test scores in the control group. Conclusions: Increased serum BDNF levels were associated with poorer visual and verbal memory, but only among AD cases. The current findings point toward an upregulation of serum BDNF as one possible mechanism linked to memory disturbances in AD though it does not appear to be linked to disease severity.

The differential impact of depressive symptom clusters on cognition in a rural multi‐ethnic cohort: a Project FRONTIER study

To examine the differential impact of depressive symptom clusters on neuropsychological functioning in a rural‐dwelling, multi‐ethnic cohort.

The Link between Cognitive Measures and ADLs and IADL Functioning in Mild Alzheimer's: What Has Gender Got to Do with It?

Objectives. To investigate the link between neurocognitive measures and various aspects of daily living (ADL and IADL) in women and men with mild Alzheimers disease (AD). Methods. Participants were 202 AD patients (91 male, 111 female) with CDR global scores of ≤1. ADLs and IADLs ratings were obtained from caregivers. Cognitive domains were assessed with neuropsychological testing. Results. Memory and executive functioning were related to IADL scores. Executive functioning was linked to total ADL. Comparisons stratified on gender found attention predicted total ADL score in both men and women. Attention predicted bathing and eating ability in women only. Language predicted IADL functions in men (food preparation) and women (driving). Conclusions. Associations between ADLs/IADLs and memory, learning, executive functioning, and language suggest that even in patients with mild AD, basic ADLs require complex cognitive processes. Gender differences in the domains of learning and memory area were found.

Depressive symptom clusters and neuropsychological performance in mild Alzheimer's and cognitively normal elderly.

Objectives. Determine the relationship between depressive symptom clusters and neuropsychological test performance in an elderly cohort of cognitively normal controls and mild Alzheimers disease (AD). Design. Cross-sectional analysis. Setting. Four health science centers in Texas. Participants. 628 elderly individuals (272 diagnosed with mild AD and 356 controls) from ongoing longitudinal study of Alzheimers disease. Measurements. Standard battery of neuropsychological tests and the 30-item Geriatric Depression Scale with regressions model generated on GDS-30 subscale scores (dysphoria, apathy, meaninglessness and cognitive impairment) as predictors and neuropsychological tests as outcome variables. Follow-up analyses by gender were conducted. Results. For AD, all symptom clusters were related to specific neurocognitive domains; among controls apathy and cognitive impairment were significantly related to neuropsychological functioning. The relationship between performance and symptom clusters was significantly different for males and females in each group. Conclusion. Findings suggest the need to examine disease status and gender when considering the impact of depressive symptoms on cognition.

Executive functioning mediates the link between other neuropsychological domains and daily functioning: a Project FRONTIER study.

BACKGROUNDnThe purpose of this study was to examine the mediating impact of executive functioning on the link between other neuropsychological domain scores and informant-based rating of functional status.nnnMETHODSnData on 181 participants were analyzed from an ongoing epidemiological study of rural health, Project FRONTIER (mean age = 64.6 ± 13.8 years, 69% women, 42% Mexican American). Executive functioning was assessed by the EXIT25 and other neuropsychological domains were assessed via the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Informant-based rating of functional status was assessed via the Clinical Dementia Rating Scale sum of boxes scores (CDR SB).nnnRESULTSnRBANS Index scores were each significantly (p < 0.05) related to CDR SB scores and EXIT25 scores. EXIT25 score was a significant partial mediator of the link between four RBANS indices (Immediate Memory, Attention, Visuospatial/Construction, Delayed Memory) and CDR SB scores, and a complete mediator of the fifth index (Language).nnnCONCLUSIONnExecutive functioning is a mediator of the link between other neuropsychological domains and daily functioning. Neuropsychological assessments that do not measure executive functioning will provide only a partial clinical picture with adults and elders.

Normative performance on the executive clock drawing task in a multi-ethnic bilingual cohort: a project FRONTIER study.

The executive clock drawing task (CLOX) test is a neuropsychological measure intended to aid in the assessment and detection of dementia in older populations. Few studies have provided normative data for this measure, with even less research available regarding the impact of sociodemographic factors on test scores. This study presents normative data for the CLOX in a sample of English and Spanish‐speaking Hispanic and non‐Hispanic Whites.

The Link between Sleep Disturbance and Depression among Mexican Americans: A Project FRONTIER Study

OBJECTIVEnTo examine the link between disturbed sleep and depression scores in Mexican Americans and non-Hispanic Whites.nnnMETHODSnData were analyzed for 566 participants (45% Mexican Americans) who were part of a rural healthcare study, Project FRONTIER. Mean age was 55.5 years for Mexican Americans (70% female) and 65.6 years for non-Hispanic Whites (69% female). Self-reported sleep disturbance was entered as the predictor, GDS-30 total and factor scores as the outcome variables, and age, sex, education, BMI, and medical diagnoses (hyperlipidemia, diabetes mellitus, and hypertension) entered as covariates.nnnRESULTSnMexican Americans reported higher rates of sleep disturbances (25%) than non-Hispanic whites (17%). Sleep disturbances were significantly associated with GDS-30 total scores and the factors Dysphoria and Cognitive Impairment in both Mexican Americans and non-Hispanic whites.nnnCONCLUSIONSnIn this study, Mexican Americans reported higher rates of sleep disturbances than non-Hispanic whites. Disturbed sleep was positively associated with depression and the factor scores for Dysphoria and Cognitive Impairment in both groups. Given the paucity of research on sleep disorders in Mexican Americans, identifying what sleep disorders are present and the impact treating these sleep disorders have on depression warrant further investigation.

Reproductive health and Millennium Development Goals: sustaining and planning for target attainment

Perhaps, one of the most well-known projects today for planned change is the United Nations Millennium project with eight Millennium Developmental Goals to be achieved by 2015. Of the eight goals, three relate to reproductive health. This study assesses the effect of selected factors on current reproductive health levels in developing countries. Using data for 122 countries, three geographic clusters distinct in reproductive health characteristics were identified. We found that countries with high level of reproductive health enjoyed high levels of reproductive rights. Our findings underscore the relevance of a human rights-based approach towards reproductive health Millennium Development Goals.

The Link between Potassium and Mild Cognitive Impairment in Mexican-Americans

Background: Recent evidence suggests that increasing dietary intake of minerals reduces the risk of dementia. This study aimed to examine the relationship between potassium and diagnosis of mild cognitive impairment (MCI) in a sample of older Mexican-Americans from rural and urban populations. Methods: The sample was formed of a total of 139 participants with MCI and 371 normal controls from two independent cohorts: a rural cohort (Facing Rural Obstacles to Healthcare Now through Intervention, Education and Research [Project FRONTIER]) and an urban cohort (the Health and Aging Brain among Latino Elders [HABLE] study). Serum electrolytes examined were sodium and potassium. Age and education were entered in the model as covariates. Results: Across both cohorts, the Project FRONTIER (OR = 3.1; p = 0.01) and the HABLE Project (OR = 2.0; p = 0.04), the results indicated that serum potassium levels significantly increased the risk of diagnosis of MCI. Conclusion: Our finding suggested a link between serum potassium levels and a diagnosis of MCI in Mexican-Americans. The results of this study support a previous research which has suggested that the risk factors for MCI may vary by ethnicity.

CHARACTERIZATION OF WORRY AND COGNITION IN MEXICAN AMERICAN WOMEN

younger adults (Trails B-reaction time, seconds: p1⁄4.003; Stroop-reaction time, seconds: p<.001). In the older adult group, both cognitive (p1⁄4.02) and emotional empathy (p1⁄4.02) were negatively correlated with alexithymia. Cognitive empathy was also negatively correlated with Trails B reaction time (p1⁄4.03). Alexithymia positively correlated with time to complete Trails B (p1⁄4.02) and Stroop (p1⁄4.01). In younger adults, cognitive empathy negatively correlated with alexithymia (p1⁄4.04).Conclusions:Older adults, on average, tend to report lower cognitive empathy, higher alexithymia, and perform more poorly on executive function tasks than younger adults. However, we find within the older adult group, those who have higher cognitive empathy also have higher executive function and greater emotional awareness, suggesting that relative preservation of both cognitive and socioemotional functions may co-occur in some older adults. Future studiesmay investigate the degree towhich age-related neural differences may help to explain differences in empathy, alexithymia, and executive function among older adults.