Melissa H. Kitner-Triolo

Factorial invariance of the CES-D in low socioeconomic status African Americans compared with a nationally representative sample

This study examined the factor structure of the Center for Epidemiologic Studies Depression Scale (CES-D) in low socioeconomic status African Americans (n=426). Confirmatory factor analysis indicated that the four factors-(1) depressed affect, (2) positive affect, (3) somatic complaints, and (4) interpersonal problems-of the CES-D scale previously found in the general population were supported in this sample. These results were cross-validated in other nationally representative samples of African-American participants (n=988) and Caucasians (n=666), and the four-factor structure of the CES-D scale replicated in all three groups in this study. An alternative model was also tested with the factors depressed affect and somatic complaints combined as a single factor, a finding often reported in minority groups. Results indicated a significantly poorer fit for the three-factor model compared with the four-factor model for all three groups. In addition, higher loading differences were significantly evident between African-American and Caucasian groups, while higher loading similarities were found between the two African-American groups. These findings provide further evidence of measurement equivalency of the CES-D scale in samples with differential characteristics including race and socioeconomic status.

Statins and serum cholesterol's associations with incident dementia and mild cognitive impairment

Background Statin use and serum cholesterol reduction have been proposed as preventions for dementia and mild cognitive impairment (MCI). Methods 1604 and 1345 eligible participants from the Baltimore Longitudinal Study of Aging (BLSA) were followed after age 50 for a median time of around 25 years, to examine the incidence of dementia (n=259) and MCI (n=138), respectively. Statin use (ever-use and time-dependent use), total cholesterol levels (TC; first visit and time-dependent), TC change trajectory from first visit and high-density lipoprotein (HDL-C):TC ratio (first visit and time-dependent) were the main exposures of interest. Cox proportional hazards models were used. Results Participants with incident dementia had a higher first-visit TC compared with participants who remained free of dementia and MCI, while first-visit TC was higher among statin ever-users compared with never-users (age-unadjusted associations). Statin users had a two- to threefold lower risk of developing dementia (HR=0.41; 95% CI 0.18 to 0.92), but not MCI, when considering time-dependent ‘statin use’ with propensity score model adjustment. This association remained significant independently of serum cholesterol exposures. An elevated first-visit TC was associated with reduced MCI risk (upper quartile (Q4) vs Q1: HR=0.51; 95% CI 0.29 to 0.90). Compared with the lowest quartile (Q1: 0.00–0.19), HDL-C:TC (time-dependent) in (Q2: 0.19–0.24) was associated with reduced MCI risk (HR=0.58; 95% CI 0.34 to 0.98). Among men only, TC decline from first visit was significantly associated with increased dementia risk (HR=4.21; 95% CI 1.28 to 13.85). Conclusions Statins may have multifactorial effects on dementia but not MCI risk. Future interventions may be warranted, and research should focus on optimal serum TC, HDL-C:TC ratio and TC change trajectories.

Effects of race and socioeconomic status on the relative influence of education and literacy on cognitive functioning.

Previous research has shown that reading ability is a stronger predictor of cognitive functioning than years of education, particularly for African Americans. The current study was designed to determine whether the relative influence of literacy and education on cognitive abilities varies as a function of race or socioeconomic status (SES). We examined the unique influence of education and reading scores on a range of cognitive tests in low- and higher-SES African Americans and Whites. Literacy significantly predicted scores on all but one cognitive measure in both African American groups and low-SES Whites, while education was not significantly associated with any cognitive measure. In contrast, both education and reading scores predicted performance on many cognitive measures in higher-SES Whites. These findings provide further evidence that reading ability better predicts cognitive functioning than years of education and suggest that disadvantages associated with racial minority status and low SES affect the relative influence of literacy and years of education on cognition.

Sex differences in cognitive trajectories in clinically normal older adults.

Age effects on cognitive functioning are well-documented, but effects of sex on trajectories of cognitive aging are less clear. We examined cognitive ability across a variety of measures for 1,065 to 2,127 participants (mean baseline age 64.1 to 69.7 years) from the Baltimore Longitudinal Study of Aging who were repeatedly tested over a mean follow-up interval of 3.0 to 9.0 years with a mean of 2.3 to 4.4 assessments. Memory and other cognitive tests were administered at each visit, assessing mental status, verbal learning and memory, figural memory, language, attention, perceptuomotor speed and integration, executive function, and visuospatial ability. Importantly, participants free from cognitive impairment at all time points were used in the analyses. Results showed that for all tests, higher age at baseline was significantly associated with lower scores, and performance declined over time. In addition, advancing age was associated with accelerated longitudinal declines in performance (trend for mental status). After adjusting for age, education, and race, sex differences were observed across most tests of specific cognitive abilities examined. At baseline, males outperformed females on the 2 tasks of visuospatial ability, and females outperformed males in most other tests of cognition. Sex differences in cognitive change over time indicated steeper rates of decline for men on measures of mental status, perceptuomotor speed and integration, and visuospatial ability, but no measures on which women showed significantly steeper declines. Our results highlight greater resilience to age-related cognitive decline in older women compared with men.

Sex differences in the association of the apolipoprotein E epsilon 4 allele with incidence of dementia, cognitive impairment, and decline.

We examined longitudinal associations between the apolipoprotein E ε4 allele (ApoE4(+) status) and several cognitive outcomes and tested effect modification by sex. Data on 644 non-Hispanic Caucasian adults, from the Baltimore Longitudinal Study of Aging (BLSA) were used. Dementia onset, cognitive impairment and decline were assessed longitudinally. After 27.5 years median follow-up, 113 participants developed dementia. ApoE4(+) predicted dementia significantly (hazard ratio [HR] = 2.89; 95% confidence interval [CI], 1.93-4.33), with nonsignificant sex differences. Taking all time points for predicting cognition, women had significantly stronger positive associations than men between ApoE4(+) status and impairment or decline on the California Verbal Learning Test (CVLT; delayed recall and List A total recall) and on Verbal Fluency Test-Categories. This ApoE4 × sex interaction remained significant with Bonferroni correction only for CVLT-delayed recall. Taking time points prior to dementia for cognitive predictions, the positive association between impairment in CVLT-delayed recall and ApoE4(+) status remained stronger among women, though only before Bonferroni correction. While ApoE4(+) status appears to be a sex neutral risk factor for dementia, its association with verbal memory and learning decline and impairment was stronger among women.

Personality Traits Prospectively Predict Verbal Fluency in a Lifespan Sample

In a community-dwelling sample (N = 4,790; age range 14-94), we examined whether personality traits prospectively predicted performance on a verbal fluency task. Open, extraverted, and emotionally stable participants had better verbal fluency. At the facet level, dispositionally happy and self-disciplined participants retrieved more words; those prone to anxiety and depression and those who were deliberative retrieved fewer words. Education moderated the association between conscientiousness and fluency such that participants with lower education performed better on the fluency task if they were also conscientious. Age was not a moderator at the domain level, indicating that the personality-fluency associations were consistent across the life span. A disposition toward emotional vulnerability and being less open, less happy, and undisciplined may be detrimental to cognitive performance.

Thyroid Hormones Are Associated With Cognitive Function: Moderation by Sex, Race, and Depressive Symptoms

CONTEXT Recent evidence indicates that thyroid hormones may be closely linked to cognition among adults. OBJECTIVE We investigated associations between thyroid hormones and cognitive performance, while testing effect modification by sex, race, and elevated depressive symptoms (EDS). DESIGN This cross-sectional study used extensive data from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. SETTING The study was conducted in Baltimore, Maryland, from 2004 to 2009. PARTICIPANTS PARTICIPANTS were U.S. adults aged 30 to 64 years. The sample size ranged from 1275 to 1346. MAIN OUTCOME MEASURES Outcomes included 13 cognitive test scores spanning domains of learning/memory, language/verbal, attention, visuo-spatial/visuo-construction, psychomotor speed, executive function, and mental status. RESULTS Within reference ranges and after Bonferroni correction, elevated free thyroxine (fT4) was associated with better performance on tests of visuo-spatial/visuo-construction ability (overall, women, and African Americans) and learning/memory (women and African Americans), whereas a higher total thyroxine (tT4) level was associated with better performance in the domain of psychomotor speed (individuals without EDS) and higher levels of both fT4 and tT4 were linked to better language/verbal test performance among men. In contrast, higher T3(% uptake) was related to better performance on tests of visuo-spatial/visuo-construction ability and psychomotor speed among whites. When the above reference range was compared within the overall population and after Bonferroni correction, a within reference range fT4 was linked to better performance on visuo-spatial/visuo-constrution ability and psychomotor speed, whereas a below normal range TSH level (compared with the reference range) was linked to better performance in domains of psychomotor speed and attention. CONCLUSIONS Thyroid hormones and cognition are closely linked differentially by sex, race, and EDS status.

Helicobacter pylori Seropositivity and Cognitive Performance Among Us Adults: Evidence From a Large National Survey

Background Helicobacter pylori seropositivity is a potential risk for poor cognition among US adults. Methods Cross-sectional data from the National Health and Nutrition Examination Survey III, Phase 1 (1988–1991), were used. Measures included age group-specific neuropsychological test batteries and two measures of H. pylori seropositivity (immunoglobulin G [IgG] and IgG CagA) (20–59 years old: n = 2090–2,248; 60–90 years old: n = 2123–2388). We explored sex- and race-specific associations. Results Using multiple ordinary least square and zero-inflated Poisson regression models, we detected a poorer performance among those 60–90 years old with H. pylori IgG+ versus IgG− on a verbal memory test (story recall, correct items), overall (&bgr; = −0.04 [0.01], p = .010). Non-Hispanic (NH) blacks and women (20–59 years old) performed worse on the serial digits learning total errors (SDL-TE) when H. pylori IgG+ (versus IgG−), another verbal memory test (&bgr; = +0.94 [0.40; p = .029] and &bgr; = +1.19 [0.44; p = .012], respectively; p<.10 for interaction by sex and race). More trials to completion on this test (SDL-TTC) were also required among H. pylori IgG+ overall (20–59 years old; &bgr; = +0.30 [0.13], p = .033). Other race-specific associations without significant interaction by race were detected in the same direction of worse performance with seropositivity in all three major race groups and for both age categories, covering several domains of cognition. Conclusions H. pylori seropositivity markers were associated with poor cognition among US adults. Longitudinal research is needed to extrapolote those findings to cognitive decline, incident dementia, and Alzheimers disease.

Serum leptin, thyroxine and thyroid-stimulating hormone levels interact to affect cognitive function among US adults: evidence from a large representative survey.

Neuroanatomical connections point to possible interactions between areas influencing energy homeostasis and those influencing cognition. We assessed whether serum leptin, thyroxine, and thyroid stimulating hormone (TSH) levels are associated with and interact to influence cognitive performance among US adults. Data from the National Health and Nutrition Examination Survey III (1988-1994) were used. Measures included a battery of neuropsychological tests and serum leptin, thyroxine, and TSH levels (20-59-year-old: n = 1114-2665; 60-90-year-old: n = 1365-5519). Among those 20-59-year-old, the middle tertile of leptin (vs. first tertile) was inversely related to the number of errors on the symbol digits substitution test. Increased thyroxine level was associated with a poorer performance on the serial digits test in the 20-59-year-old, but a better performance on the math test in 60-90-year-old group. TSH was associated with poor performance on various tests in the 20-59-year-old, but better performance in the 60-90-year-old group. Significant antagonistic interactions were found in both age groups between thyroxine, TSH, and leptin for a number of tests, including between leptin and thyroxine in the 60-90-year-old group in their association with word recall-correct score. We found significant associations of our main exposures with cognitive function among US adults, going in opposite directions between age groups in the cases of thyroid hormonal levels, as well as some interactive effects between exposures. It is important to conduct prospective cohort studies to provide further insight into potential interventions that would assess interactive effects of various hormonal replacement regimens.

Literacy-based normative data for low socioeconomic status African Americans

Clinical neuropsychology relies on the use of appropriate test norms. Normative studies frequently stratify based on age, education, sex, and race. None to date has reported norms based on literacy, despite the substantial evidence that literacy impacts cognitive functioning. Some researchers have suggested that literacy is a more accurate reflection of academic achievement and quality of education than years of education, particularly for African Americans. The current study provides literacy-based normative data for multiple neuropsychological measures based on a sample of predominantly low socioeconomic status African Americans. These normative data should improve the diagnostic accuracy of performances by African-American clients with similar demographic backgrounds.