Penelope K. Elias

Lower cognitive function in the presence of obesity and hypertension: the Framingham heart study

OBJECTIVE: To determine the independent effects of obesity and hypertension on cognitive functioning.METHODS: Using a prospective design, male (n=551) and female (n=872) participants of the Framingham Heart Study were classified by presence or absence of obesity and hypertension based on data collected over an 18-y surveillance period. All subjects were free from dementia, stroke, and clinically diagnosed cardiovascular disease up to the time of cognitive testing. Statistical models were adjusted for age, education, occupation, cigarette smoking, alcohol consumption, total cholesterol, and a diagnosis of type II diabetes. Body mass index status (nonobese or obese) and blood pressure status (normotensive or hypertensive) were then related to cognitive performance (learning, memory, executive functioning, and abstract reasoning) on tests administered 4–6 y later.RESULTS: Adverse effects of obesity and hypertension on cognitive performance were observed for men only. Obese and hypertensive men performed more poorly than men classified as either obese or hypertensive, and the best performance was observed in nonobese, normotensive men.CONCLUSIONS: The adverse effects of obesity and hypertension in men are independent and cumulative with respect to cognitive deficit.

NIDDM and Blood Pressure as Risk Factors for Poor Cognitive Performance: The Framingham Study

OBJECTIVE To determine if NIDDM and blood pressure are risk factors for poor cognitive performance and if history and duration of NIDDM and blood pressure interact such that the risk of poor performance is greater for subjects with both NIDDM and hypertension. RESEARCH DESIGN AND METHODS We used a large prospective cohort sample with 187 NIDDM subjects and 1,624 nondiabetic subjects who were followed for 28–30 years. Cognitive function was assessed using eight tests of learning, memory, visual organization, verbal fluency attention, concept formation, and abstract reasoning. A composite score was also calculated. Odds ratios were used to estimate the relative risk of performing below the lower 25th percentile of z scores on these tests. RESULTS NIDDM and blood pressure interacted such that diagnosis and duration of NIDDM were associated with greater risk of poor performance on tests of visual memory and on the composite score for hypertensive subjects. Duration of NIDDM was associated with increased risk for poor performance on tests of verbal memory and concept formation. Insulin-treated NIDDM subjects were at higher risk for poor cognitive performance than those NIDDM subjects treated with oral agents or diet. Blood pressure level was associated independently with a measure of verbal fluency. CONCLUSIONS History and duration of NIDDM and high blood pressure are significant risk factors for poor cognitive performance. Hypertensive people with NIDDM are at greatest risk for poor performance on tests measuring visual organization and memory.

Obesity, diabetes and cognitive deficit: The Framingham Heart Study

OBJECTIVE To determine the independent effects of obesity on cognitive performance and to examine interactions between obesity and non-insulin dependent diabetes mellitus (NIDDM). METHODS Using a prospective design, male (n=551) and female (n=872) participants of the Framingham Heart Study were classified as obese (yes/no), diabetic (yes/no), and the number of diabetes-years was determined by data collected over an 18-year surveillance period. All subjects were free from dementia, stroke, and clinically diagnosed cardiovascular disease up to the time of cognitive testing. Statistical models were adjusted for age, education, occupation, native language, and cardiovascular disease risk factors. Body mass index status (non-obese or obese) and NIDDM status (diabetic/non-diabetic) were related to cognitive performance on multiple cognitive measures. RESULTS Adverse effects of obesity on cognitive performance were observed for men only. Diabetes-years related to poorer cognitive performance, but only when men and women were combined for analyses. Neither diabetes nor diabetes-years by obesity interactions were observed. CONCLUSIONS The gender-specific results for obesity, but not for diabetes, suggests that the underlying mechanisms linking them to cognition may be different.

Framingham Stroke Risk Profile and Lowered Cognitive Performance

Background and Purpose— The primary objective of this work was to describe the relationships between 10-year risk for stroke and multiple measures of cognitive performance for a large community-based sample of individuals who were free of clinical stroke and dementia at the time of risk assessment. Methods— Participants were 1011 men and 1164 women from the Framingham Offspring Study. The Framingham Stroke Risk Profile was used to assess 10-year risk of stroke. Using a cross-sectional design, we assessed 10-year risk of stroke, the predictor variable, and cognitive performance, the outcome variable, at examination 7 of the Framingham Offspring Study. Multivariable linear regression models were used to relate 10-year risk of stroke to cognitive tests measuring multiple domains of cognitive functioning. Results— With statistical adjustment for age, education, sex, and other correlates of both stroke and cognitive ability, an inverse association between increments in 10-year risk of stroke and cognitive performance level was observed for tests indexing visual-spatial memory, attention, organization, scanning, and abstract reasoning. Conclusions— In stroke- and dementia-free individuals, higher 10-year risk for stroke is associated with performance decrements in multiple cognitive domains.

Blood Pressure-Related Cognitive Decline: Does Age Make a Difference?

Systolic and diastolic blood pressures have been inversely related to cognitive performance in prospective and cross-sectional studies. However, in large, community-based samples, these findings have been limited to older adults. In this 20-year longitudinal study, we examined the relationship between baseline blood pressure and cognitive decline for 529 participants using 2 age groups (18 to 46 years and 47 to 83 years). Cognitive performance was measured over multiple examinations with the Wechsler Adult Intelligence Scale from which 4 scores were derived by factor analysis. A 2-stage growth curve method of analysis was used to model cognitive change. Results indicated that higher levels of baseline systolic blood pressure, diastolic blood pressure, mean arterial pressure, and blood pressure categories as defined by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure were significantly associated with decline in Visualization/Fluid abilities in both younger and older age groups. Young adults are as susceptible to blood pressure-related longitudinal decline in cognitive performance as are older adults.

Chronic kidney disease, creatinine and cognitive functioning

BACKGROUND Non-dialysis-dependent chronic kidney disease (CKD) is related to cognitive impairment. Previous studies have not explored the extent of impairment across multiple cognitive domains. We examined the range of specific cognitive abilities affected by CKD and whether the associations of CKD with cognition were eliminated by statistical control for cardiovascular disease correlates of CKD. METHODS We performed a community-based cross-sectional study with 923 individuals free from dementia and end-stage renal disease. Two groups were defined based on estimated glomerular filtration rate (eGFR): eGFR<60 mL/min/1.73 m(2) versus eGFR >or= 60 mL/min/1.73 m(2). Outcome measures were scores from multiple clinical tests of specific cognitive abilities. The GFR classifications and serum creatinine levels were related to measures of cognitive performance using logistic and linear regression analyses with three sets of covariates: (1) basic (age, education, gender and race); (2) basic+risk factors for cardiovascular disease (CVD) and (3) basic+risk factors for CVD+stroke. RESULTS An eGFR <60 mL/min/1.73 m(2) was present in 142 (15.4%) individuals; the mean (SD) eGFR in this subgroup was 49.7 (10.7). CKD was related to lower cognitive performance despite adjustment for CVD risk factors (CVD-RF). Adjusting for CVD-RF and stroke, odds ratios and 95% confidence intervals associated with performing in the lowest quartile of the distribution of the Global, Visual-Spatial Organization/Memory and Scanning and Tracking scores for the eGFR < 60 group were 1.97 (1.25, 3.10); 1.88 (1.21, 2.93) and 1.83 (1.56, 2.87), P < 0.01 with eGFR >or= 60 group as the reference group. CONCLUSIONS Global performance and specific cognitive functions are negatively affected early in CKD. Targeted screening for cognitive deficits in kidney disease patients early in their disease course may be warranted.

Arterial Pulse Wave Velocity and Cognition With Advancing Age

We hypothesized that carotid-femoral pulse wave velocity (PWV), a marker of arterial stiffness, interacts with age such that the magnitude of associations between PWV and cognitive performance are greater with increasing age and that this interaction is observed despite adjustments for demographic variables, mean arterial pressure, and cardiovascular risk factors. PWV was estimated using applanation tonometry in 409 dementia- and stroke-free participants of the Maine-Syracuse Longitudinal Study (24 to 92 years of age; 62.3% women). Using linear regression analyses in a cross-sectional design, associations between PWV and age and the interaction of PWV and age were examined in relation to a global composite score, the Wechsler Adult Intelligence Scale Similarities test (abstract reasoning), and 4 cognitive domains indexed by multiple cognitive measures. Adjusting for age, gender, education, height, weight, heart rate, mean arterial pressure, and antihypertensive treatment, PWV-by-age interactions were obtained for the global, visual-spatial organization and memory, scanning and tracking, and verbal episodic memory composites, as well as similarities. The combination of higher PWV and age resulted in progressively lower cognitive performance. This finding was the same with an extended model, which also included adjustment for cardiovascular risk factors and other confounds. PWV interacts with age in a multiplicative way to exert a negative influence on cognitive performance level. Early interventions to prevent an increase in arterial stiffness could possibly play an important role in the preservation of cognitive ability.

Serum cholesterol and cognitive performance in the framingham heart study

Objective: The objective of this study was to examine the relationship between total cholesterol (TC) and cognitive performance within the context of the Framingham Heart Study, a large, community-based, prospective investigation of cardiovascular risk factors. Methods: Participants were 789 men and 1105 women from the Framingham Heart Study original cohort who were free of dementia and stroke and who received biennial TC determinations over a 16- to 18-year surveillance period. Cognitive tests were administered 4 to 6 years subsequent to the surveillance period and consisted of measures of learning, memory, attention/concentration, abstract reasoning, concept formation, and organizational abilities. Statistical models were adjusted for multiple demographic and biological covariates. Results: There was a significant positive linear association between TC and measures of verbal fluency, attention/concentration, abstract reasoning, and a composite score measuring multiple cognitive domains. Performance levels for three clinically defined groups were examined. Participants with “desirable” TC levels (<200 mg/dL) performed less well than participants with borderline-high TC levels (200–239 mg/dL) and participants with high TC levels (∃240 mg/dL). Conclusions: Lower naturally occurring TC levels are associated with poorer performance on cognitive measures, which place high demands on abstract reasoning, attention/concentration, word fluency, and executive functioning. CVD = cardiovascular disease; TC = total cholesterol; MAP = mean arterial pressure; BMI = body mass index.

Role of age, education, and gender on cognitive performance in the Framingham Heart Study: community-based norms.

Normative data are presented for a neuropsychological test battery (Kaplan-Albert) consisting of subtests from the original Wechsler Adult Intelligence and Memory Scales and the Benton and Hamsher Aphasia Examination. Analyses were based on archival data resulting from administration (1976-1978) of the battery to community residents participating in the Framingham Heart Study, a prospective, longitudinal study of cardiovascular risk factors. Using 3 age groups (55-64, 65-74, and 75-88 years) and 4 education levels (5-8, 9-11, 12, > 12 years), individuals were stratified by age, gender, and education. Multiple linear regression analysis was used to relate main effects (age, education, and gender) and interactions of these effects to 9 test scores and to 2 composite scores identified by factor analysis. The oldest participants who had the fewest years of formal education had the lowest performance levels, with lower levels of performance for men than women in this least educated elderly cohort.

Neuropsychological test performance, cognitive functioning, blood pressure, and age : the Framingham Heart Study

Interactions of three indices of blood pressure (systolic blood pressure, diastolic blood pressure, and chronicity of hypertension) and age-cohort membership were examined for a sample of 1,695 stroke-free participants of the Framingham Heart Study, ages 55-88 years. Blood pressure level and chronicity of hypertension were assessed over five biennial examinations performed between 1956 and 1964, a time when few hypertensives were being treated, and were related to neuropsychological tests administered between 1976 and 1978. Multiple linear regression methods were used to examine Age x Blood Pressure (or Chronicity of Hypertension) interactions in alternative analyses involving three age groups (55-64 years, 65-74 years, and 75-88 years) and age as a continuously distributed variable (age in years). Interactions were either statistically nonsignificant or trivial with respect to magnitude of effect. This was true when interaction terms (Age x Blood Pressure Level or Age x Chronicity of Hypertension) were controlled for blood pressure, age, education, occupation, cigarette smoking, alcohol consumption, gender, and antihypertensive treatment. The Age x Blood Pressure model as it pertains to older adults was not supported, but independent associations (with all covariables controlled) between the indices of blood pressure and cognitive functioning were statistically significant.