Adina Zeki Al Hazzouri

Impact of Hypertension on Cognitive Function: A Scientific Statement From the American Heart Association.

Background—Age-related dementia, most commonly caused by Alzheimer disease or cerebrovascular factors (vascular dementia), is a major public health threat. Chronic arterial hypertension is a well-established risk factor for both types of dementia, but the link between hypertension and its treatment and cognition remains poorly understood. In this scientific statement, a multidisciplinary team of experts examines the impact of hypertension on cognition to assess the state of the knowledge, to identify gaps, and to provide future directions. Methods—Authors with relevant expertise were selected to contribute to this statement in accordance with the American Heart Association conflict-of-interest management policy. Panel members were assigned topics relevant to their areas of expertise, reviewed the literature, and summarized the available data. Results—Hypertension disrupts the structure and function of cerebral blood vessels, leads to ischemic damage of white matter regions critical for cognitive function, and may promote Alzheimer pathology. There is strong evidence of a deleterious influence of midlife hypertension on late-life cognitive function, but the cognitive impact of late-life hypertension is less clear. Observational studies demonstrated a cumulative effect of hypertension on cerebrovascular damage, but evidence from clinical trials that antihypertensive treatment improves cognition is not conclusive. Conclusions—After carefully reviewing the literature, the group concluded that there were insufficient data to make evidence-based recommendations. However, judicious treatment of hypertension, taking into account goals of care and individual characteristics (eg, age and comorbidities), seems justified to safeguard vascular health and, as a consequence, brain health.

Pulse Wave Velocity and Cognitive Decline in Elders The Health, Aging, and Body Composition Study

Background and Purpose— Arterial stiffness is a measure of subclinical cardiovascular disease and increases with age. This study examines the association between arterial stiffness and cognitive decline in a cohort of older adults. Methods— A total of 2488 subjects with baseline measure of arterial stiffness (mean age, 74.2 years; 52.3% women) were prospectively followed over 9 years in the Health, Aging, and Body Composition Study. Arterial stiffness was measured as pulse wave velocity (PWV) and analyzed in tertiles. Cognitive function was assessed using the Modified Mini-Mental State examination at baseline and repeated at years 3, 5, 8, and 10. Lower Modified Mini-Mental State examination scores indicate worse function. We fit linear mixed models to examine longitudinal changes in cognitive function over the 9 years of follow-up and logistic regression models, restricted to 1331 participants, to examine cognitive impairment defined as a decrease of ≥5 points after 9 years. We adjusted for sociodemographics, Apoe4, and cardiovascular disease risk factors. Results— The annual decrease in Modified Mini-Mental State examination scores was 0.30 points at low PWV (95% confidence interval [CI], −0.37 to −0.22), 0.46 points at middle PWV (95% CI, −0.54 to −0.39), and 0.45 points at high PWV (95% CI, −0.53 to −0.38), from fully adjusted linear mixed models. In fully adjusted models, the odds of cognitive impairment after 9 years of follow-up was 40% greater for subjects with middle PWV (odds ratio [OR], 1.40; 95% CI, 1.03–1.92) and 59% greater for subjects with high PWV (OR, 1.59; 95% CI, 1.16–2.18), compared with low PWV. Conclusions— High arterial stiffness was modestly associated with cognitive decline and impairment. Interventions to prevent arterial stiffness may be effective in delaying cognitive decline.

Life-Course Socioeconomic Position and Incidence of Dementia and Cognitive Impairment Without Dementia in Older Mexican Americans: Results From the Sacramento Area Latino Study on Aging

There have been few investigations of the link between changes in life-course socioeconomic position (SEP) and cognitive decline or incidence of dementia. The authors examined the impact of changes in life-course SEP on incidence of dementia and cognitive impairment but not dementia (CIND) over a decade of follow-up. Participants of Mexican origin (n = 1,789) were members of the Sacramento Area Latino Study on Aging cohort. Incidence of dementia/CIND was ascertained by using standard diagnostic criteria. SEP indicators at 3 life stages (childhood, adulthood, and midlife) were used to derive a measure of cumulative SEP (range, 0 to 8) and SEP mobility. Nearly 24% of the sample maintained a low SEP throughout life. Hazard ratios and 95% confidence intervals were computed from Cox proportional hazards regression models. In fully adjusted models, participants with a continuously high SEP had lower hazard ratios for dementia/CIND compared with those with a continuously low SEP at all 3 life stages (hazard ratio = 0.49, 95% confidence interval: 0.24, 0.98; P = 0.04). In age-adjusted models, participants experienced a 16% greater hazard of dementia/CIND with every 1-unit increase in cumulative SEP disadvantage across the life course (hazard ratio = 1.16, 95% confidence interval: 1.01, 1.33; P = 0.04). Early exposures to social disadvantage may increase the risk of late-life dementia.

Central Obesity, Leptin and Cognitive Decline: the Sacramento Area Latino Study on Aging

Background/Aims: Central obesity is a risk factor for cognitive decline. Leptin is secreted by adipose tissue and has been associated with better cognitive function. Aging Mexican Americans have higher levels of obesity than non-Hispanic Whites, but no investigations examined the relationship between leptin and cognitive decline among them or the role of central obesity in this association. Methods: We analyzed 1,480 dementia-free older Mexican Americans who were followed over 10 years. Cognitive function was assessed every 12–15 months with the Modified Mini Mental State Exam (3MSE) and the Spanish and English Verbal Learning Test (SEVLT). Results: For females with a small waist circumference (≤35 inches), an interquartile range difference in leptin was associated with 35% less 3MSE errors and 22% less decline in the SEVLT score over 10 years. For males with a small waist circumference (≤40 inches), an interquartile range difference in leptin was associated with 44% less 3MSE errors and 30% less decline in the SEVLT score over 10 years. There was no association between leptin and cognitive decline among females or males with a large waist circumference. Conclusion: Leptin interacts with central obesity in shaping cognitive decline. Our findings provide valuable information about the effects of metabolic risk factors on cognitive function.

Leptin, Mild Cognitive Impairment, and Dementia Among Elderly Women

BACKGROUND The association between obesity and dementia has been inconsistent, possibly due to changes in body composition often seen in old age. Leptin may be associated with better cognitive function. However, neuroprotection may be inhibited among obese subjects possibly due to leptin resistance. We sought to determine (i) if leptin is associated with risk of dementia or mild cognitive impairment (MCI) in a cohort of very old women, (ii) if this association is modified by obesity, and (iii) if leptin is a stronger risk factor compared with traditional anthropometric measures. METHODS We studied 579 older women (mean age 82.6 years) from the ongoing prospective cohort Study of Osteoporotic Fractures, who were dementia-free at year-16 examination (our study baseline). Leptin (ng/mL) was measured using year-16 frozen serum, and anthropometric measures were collected during the same visit. Diagnosis of dementia/MCI was determined at year-20 examination. RESULTS There was evidence for a multiplicative interaction between log leptin and categorical body mass index (p = .03). Among women with body mass index <25kg/m(2) (n = 190), 1SD difference in log leptin (0.91ng/mL) was associated with 32% lower odds of dementia/MCI (OR = .68; 95% CI = .46, .99), after adjustment. The association was not significant among women with body mass index ≥25kg/m(2) (n = 377). Traditional anthropometric measures such as weight, height, and body mass index were not associated with dementia/MCI. CONCLUSIONS In this cohort of very old women, higher serum leptin was prospectively associated with lower odds of dementia/MCI in women with normal body mass index, but not in overweight or obese women. Leptin may be a better predictor of dementia/MCI than traditional anthropometric measures.

Neighborhood Socioeconomic Context and Cognitive Decline Among Older Mexican Americans: Results From the Sacramento Area Latino Study on Aging

In 1 previous study, it was shown that neighborhood socioeconomic disadvantage is associated with cognitive decline among Latinos. No studies have explored whether and to what extent individual-level socioeconomic factors account for the relation between neighborhood disadvantage and cognitive decline. The purpose of the present study was to assess the influence of neighborhood socioeconomic position (SEP) on cognitive decline and examine how individual-level SEP factors (educational level, annual income, and occupation) influenced neighborhood associations over the course of 10 years. Participants (n = 1,789) were community-dwelling older Mexican Americans from the Sacramento Area Latino Study on Aging. Neighborhood SEP was derived by linking the participants individual data to the 2000 decennial census. The authors assessed cognitive function with the Modified Mini-Mental State Examination. Analyses used 3-level hierarchical linear mixed models of time within individuals within neighborhoods. After adjustment for individual-level sociodemographic characteristics, higher neighborhood SEP was significantly associated with cognitive function (β = -0.033; P < 0.05) and rates of decline (β = -0.0009; P < 0.10). After adjustment for individual educational level, neighborhood SEP remained associated with baseline cognition but not with rates of decline. Differences in individual educational levels explained most of the intra- and interneighborhood variance. These results suggest that the effect of neighborhood SEP on cognitive decline among Latinos is primarily accounted for by education.

Reduced Heart Rate Variability Is Associated With Worse Cognitive Performance in Elderly Mexican Americans

Reduced heart rate variability is a strong predictor of cardiovascular risk factors, cardiovascular events, and mortality and thus may be associated with cognitive neurodegeneration. Yet, this has been relatively unexplored, particularly in minority populations with high cardiovascular burden. We used data from the Sacramento Area Latino Study on Aging to examine the cross-sectional association of reduced heart rate variability with cognitive function among elderly Mexican Americans. A total of 869 participants (mean age, 75 years; 59% women) had their 6-minute heart rate variability measured using an ECG monitor and respiration pacer in response to deep breathing. We used the mean circular resultant, known as R bar, as a measure of heart rate variability and categorized it into quartiles (Q1 to Q4 of R bar: reduced to high heart rate variability). Cognitive function was assessed using the modified Mini-Mental State Examination, a 100-point test of global cognitive function, and the Spanish and English verbal learning test, a 15-point test of verbal memory recall. In fully adjusted linear regression models, participants in quartile 1 had a 4-point lower modified Mini-Mental State Examination score (P<0.01), those in quartile 2 had a 2-point lower score (P=0.04), and those in quartile 3 had a 1-point lower score (P=0.35) compared with those in the highest quartile of R bar. Reduced R bar was not associated with verbal memory. Our results suggest that reduced heart rate variability is associated with worse performance on the test of global cognitive function, above and beyond traditional cardiovascular risk factors.

Long-term Cumulative Depressive Symptom Burden and Risk of Cognitive Decline and Dementia Among Very Old Women

BACKGROUND Depressive symptoms and cognitive outcomes are strongly interrelated. Despite that rates of depressive symptoms fluctuate during late life, little is known about the impact of long-term cumulative depressive symptom burden on cognitive decline and dementia in older adults. This study examines the association of nearly 20 years of cumulative depressive symptoms with cognitive outcomes in a cohort of older women. METHODS We assessed depressive symptoms in 7,240 women using the Geriatric Depression scale (GDS) at serial visits. We used a Poisson model with random slopes to estimate GDS trajectories for each participant from baseline to death or end of follow-up, and then characterized depressive symptom burden by quartile of the area under the curve. We assessed cognitive outcomes using repeated measures of the Mini-Mental State Examination (MMSE) and Trails B score over 20 years, Year-20 neuropsychological test battery, and adjudicated dementia and mild cognitive impairment (MCI). RESULTS Adjusting for potential confounders, compared with women in the lowest quartile of cumulative depressive symptoms burden, women in the highest quartile had 21% more MMSE errors over time (95% CI = 17%, 26%), 20% worse Trails B score over time (95% CI = 17%, 23%), worse scores on most of the Year-20 cognitive tests, and a twofold greater likelihood of developing dementia or MCI (95% CI = 1.48, 3.11). CONCLUSIONS Long-term cumulative depressive symptom burden was associated with cognitive decline and risk of dementia or MCI. Older adults with a history of depression should be closely monitored for recurrent episodes or unresolved depressive symptoms as well as any cognitive deficits.

Subclinical atherosclerotic calcification and cognitive functioning in middle-aged adults: The CARDIA study

OBJECTIVE Cardiovascular risk factors in middle-age are associated with cognitive impairment and dementia in older age. Less is known about the burden of calcified subclinical atherosclerosis and cognition, especially in midlife. We examined the association of coronary artery and abdominal aortic calcified plaque (CAC and AAC, respectively) with cognitive functioning in middle-aged adults. METHODS This cross-sectional study included 2510 black and white adults (age: 43-55 years) without heart disease or stroke who completed a year 25 follow-up exam (2010-11) as part of the Coronary Artery Risk Development in Young Adults Study. CAC and AAC were measured with non-contrast computed tomography. Cognition was assessed with the Digit Symbol Substitution Test (DSST) (psychomotor speed), Stroop Test (executive function), and Rey Auditory Verbal Learning Test (RAVLT) (verbal memory). RESULTS A greater amount of CAC and AAC was associated with worse performance on each test of cognitive function after adjustment for age, sex, race, education, and study center. Associations were attenuated, but remained significant for the DSST and RAVLT following additional adjustment for vascular risk factors, including adiposity, smoking, alcohol use, dyslipidemia, hypertension, and diabetes. Compared to participants without CAC or AAC, those with both CAC and AAC, but not CAC or AAC alone was associated with lower DSST scores (p < 0.05). CONCLUSIONS In this community-based sample, greater subclinical atherosclerotic calcification was associated with worse psychomotor speed and memory in midlife. These findings underscore the importance of a life course approach to the study of cognitive impairment with aging.

Gender Differences in Physical Disability Among Older Adults in Underprivileged Communities in Lebanon

Objective: To examine the role of health conditions, socioeconomic, and socioenvironmental factors in explaining gender differences in physical disability among older adults. Method: We compared 412 women and 328 men residing in underprivileged communities in Lebanon on their activities of daily living (ADL), instrumental activities of daily living (IADL), and physical tasks (PT). Binary logistic regression analyses adjusting for possible explanatory covariates were conducted sequentially. Results: Women showed higher prevalence rates of ADL, IADL, and PT compared to men. Gender disparities in ADL disability were explained by chronic-disease risk factors and health conditions (OR = 1.46; 95% CI = 0.94-2.25). The odds of disability in IADL and PT remained significantly higher for women compared to men after accounting for all available covariates. Discussion: These results suggest underlying differences in functional status between women and men, yet, may have been influenced by the sensitivity of the measures to the social context and gendered environment surrounding daily activities.