Carotid Endarterectomy in Older Women and Men in the United States: Trends in Ethnic Disparities

Trends in utilization of carotid endarterectomy (CEA) among elderly ethnic minorities have received little attention. Data from the U.S. Centers for Medicare and Medicaid Services were examined for the years 1990 through 2000. In women and men, the rate of CEA per 100,000 non-HMO beneficiaries aged ≥65 years increased in African Americans and in European Americans between 1990 and 1995, with only small changes thereafter. Between 1990 and 2000, the ratio of rates in European Americans to those in African Americans have decreased slightly, i.e., in women from 2.63 in 1990 to 2.24 (15%) in 2000 and in men from 3.94 to 3.39 (14%). Large ethnic differences in utilization of CEA persist in the elderly requiring further evaluation.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569305

High-density Lipoprotein Cholesterol, Cognitive Function and Mortality in a U.S. National Cohort

Low levels of both high density lipoprotein cholesterol (HDL) and cognitive function are associated with increased mortality risk. HDL plays an important role in brain metabolism. We test the hypotheses that the relative protective effect of high HDL level as related to mortality is greater in persons with impaired cognitive function than in others. Data were analyzed from a longitudinal mortality follow-up study of 4911 American men and women aged 60 years and over examined in 1988-1994 followed an average 8.5 yr. Measurements at baseline included HDL, a short index of cognitive function (SICF), socio-demographics, health status, and self-reported leisure-time physical activity. In proportional hazards regression analysis, no significant interaction of HDL with cognitive function was found (p = 0.08); there was a significant age-SICF interaction. After stratifying by age and adjusting for confounding by multiple variables, independent associations of HDL and SICF score with survival were strongest among the oldest persons. Consistent with its association with HDL, cognitive function and survival, controlling in addition for physical activity reduced the associations. In a nationwide cohort of older Americans, analyses demonstrated a lower risk of death independent of confounders among those high HDL and SICF scores, strongest among the oldest persons

Population Surveillance of Dementia Mortality

Geographic and temporal variation in occurrence of dementia within the US has received little attention despite its importance for generation of new etiologic hypotheses and health services research. We examine methodological problems in the use of vital statistics data for assessing variation over time, among states and within states in the US. We analyzed the US multiple cause of death files for 2005–2006 and 1999–2000 US deaths with Alzheimer’s Disease (International Classification of Disease 10th revision code G30) and other dementias (codes F01, F02, R54) coded as underlying or contributing cause of death based on the death certificate. Age-adjusted death rates were computed by year, state or county for persons aged 65 years and over. In 2005–2006 combined, 555,904 total deaths occurred with any dementia type (212,386 for Alzheimer’s disease) coded as underlying or contributing cause. Among the states, age-adjusted rates per 100,000 per year varied by two fold ranging from 458 in New York to 921 in Oregon. Similar geographic patterns were seen for Alzheimer’s disease. However, between 1999–2000 and 2005–2006 the US death rate for all dementia increased only from 559 to 695 (24%) while that for Alzheimer’s disease doubled from 135 to 266. Use of specific (G30, F01) versus non-specific diagnoses (F02, R54) varied among states and over time, explaining most of the temporal increase in rate of Alzheimer’s disease. Further research is needed to assess artifacts of diagnosis, certification or coding, utilization of health services, versus biological variation as possible causes of temporal and geographic variation to enhance utility of mortality data for dementia monitoring and research

Neuroprotection and Neurodegeneration in Alzheimer's Disease: Role of Cardiovascular Disease Risk Factors, Implications for Dementia Rates, and Prevention with Aerobic Exercise in African Americans

Prevalence of Alzheimer's disease (AD) will reach epidemic proportions in the United States and worldwide in the coming decades, and with substantially higher rates in African Americans (AAs) than in Whites. Older age, family history, low levels of education, and ɛ4 allele of the apolipoprotein E (APOE) gene are recognized risk factors for the neurodegeneration in AD and related disorders. In AAs, the contributions of APOE gene to AD risk continue to engender a considerable debate. In addition to the established role of cardiovascular disease (CVD) risk in vascular dementia, it is now believed that CVD risk and its endophenotype may directly comediate AD phenotype. Given the pleiotropic effects of APOE on CVD and AD risks, the higher rates of CVD risks in AAs than in Whites, it is likely that CVD risks contribute to the disproportionately higher rates of AD in AAs. Though the advantageous effects of aerobic exercise on cognition is increasingly recognized, this evidence is hardly definitive, and data on AAs is lacking. In this paper, we will discuss the roles of CVD risk factors in the development of AD and related dementias, the susceptibility of these risk factors to physiologic adaptation, and fitness-related improvements in cognitive function. Its relevance to AD prevention in AAs is emphasized

Smoking, Cognitive Function and Mortality in a U.S. National Cohort Study

Previous studies report that low levels cognitive function and history of smoking are associated with increased mortality risk. Elderly smokers may have increased risk of dementia, but risk in former smokers is unclear. We tested the hypotheses that the harmful effect of impaired cognitive function as related to mortality is greater in persons smoking at baseline than in others. Further, we used serum cotinine levels to assess recall bias of smoking history by cognitive function level. Data were analyzed from a longitudinal mortality follow-up study of 4,916 American men and women aged 60 years and over, examined in 1988–1994 with complete data followed an average 8.5 years. Measurements at baseline included smoking history, a short index of cognitive function (SICF), serum cotinine and socio-demographics. Death during follow-up occurred in 1,919 persons. In proportional hazards regression analysis, a significant interaction of current smoking with cognitive function was not found; but there was a significant age-smoking interaction. After adjusting for confounding by age or multiple variables, current smoking associated with over 2-fold increased mortality (hazards ratio and 95% confidence limits current versus never smoking 2.13, 1.75–2.59) and SICF with 32% reduction in mortality; top versus bottom SICF stratum 0.68, 0.53–0.88). Serum cotinine data revealed substantial recall bias of smoking history in persons with cognitive impairment. However analyses correcting for this bias did not alter the main conclusions: In a nationwide cohort of older Americans, analyses demonstrated a lower risk of death independent of confounders among those with high SICF scores and never smokers, without a significant interaction of the two

Oxygen-Induced Surface Reconstructions on Curved Ag(111)

The adsorption of oxygen and the resultant O-induced surface reconstructions are key components in heterogeneously catalyzed reactions on silver metal surfaces. O uptake and reconstructions on planar Ag(111) are well-characterized, and in this paper, we show that curved Ag(111) features similar O adsorption and reconstructions. Through a systematic scanning tunneling microscope study of a curved Ag(111) single crystal exposed to gas-phase atomic oxygen at a temperature of 525 K, we observed Oad and, upon higher coverages, saw p(4 4) and p(4 5 p3) reconstructions form on both the A-type and B-type steps. Exposures at low temperatures (\u3c 500 K) resulted in the formation of subsurface oxygen and the appearance of a stripe pattern and amorphous phase on the surface. Upon heating, stable surface reconstructions were formed. Although the geometric arrangement of atoms along the steps were different, A-type and B-type steps formed the same reconstructions. In addition, the B-type steps also saw the formation of several different features atop the oxygen reconstructions

A cross-sectional study of vascular risk factors in a rural South African population : data from the Southern African Stroke Prevention Initiative (SASPI)

Background: Rural sub-Saharan Africa is at an early stage of economic and health transition. It is predicted that the 21st century will see a serious added economic burden from non-communicable disease including vascular disease in low-income countries as they progress through the transition. The stage of vascular disease in a population is thought to result from the prevalence of vascular risk factors. Already hypertension and stroke are common in adults in sub-Saharan Africa. Using a multidisciplinary approach we aimed to assess the prevalence of several vascular risk factors in Agincourt, a rural demographic surveillance site in South Africa. Methods: We performed a cross sectional random sample survey of adults aged over 35 in Agincourt (population ≈ 70 000). Participants were visited at home by a trained nurse who administered a questionnaire, carried out clinical measurements and took a blood sample. From this we assessed participants' history of vascular risk, blood pressure using an OMRON 705 CP monitor, waist circumference, body mass index (BMI), ankle brachial index (ABI), and total and HDL cholesterol. Results: 402 people (24% men) participated. There was a high prevalence of smoking in men, but the number of cigarettes smoked was small. There was a striking difference in mean BMI between men and women (22.8 kg/m2 versus 27.2 kg/m2), but levels of blood pressure were very similar. 43% of participants had a blood pressure greater than 140/90 or were on anti-hypertensive treatment and 37% of participants identified with measured high blood pressure were on pharmacological treatment. 12% of participants had an ABI of < 0.9, sugesting the presence of sub-clinical atheroma. 25.6% of participants had a total cholesterol level > 5 mmol/l. Conclusion: We found a high prevalence of hypertension, obesity in women, and a suggestion of subclinical atheroma despite relatively favourable cholesterol levels in a rural South African population. South Africa is facing the challenge of an emerging epidemic of vascular disease. Research to establish the social determinates of these risk factors and interventions to reduce both individual and population risk are required

Opposite Associations of Trunk and Leg Fat Depots with Plasma Ferritin Levels in Middle-Aged and Older Chinese Men and Women

Background: Few data have been published on the associations of ferritin with trunk and leg fat depots. We aimed to investigate these associations in a Chinese population. Methodology: Trunk fat mass and leg fat mass were determined in a cross-sectional sample of 1,150 Chinese (479 men and 671 women) aged 50–70 years by dual-energy X-ray absorptiometry scan. Fasting plasma ferritin was measured. Principal Findings: Plasma ferritin was positively correlated with waist circumference, waist-to-hip ratio, total body fat and trunk fat mass, but inversely correlated with leg fat mass in men (r = 0.16, 0.26, 0.19, 0.22 and 20.12, respectively, all P,0.05) and women (r = 0.16, 0.16, 0.08, 0.17 and 20.12, respectively, all P,0.05). Multivariate regression analysis showed that ferritin levels increased with larger trunk fat mass (b = 0.33 6 0.08 for men and b = 0.21 6 0.05 for women, both P,0.001) while decreased with larger leg fat mass (b = 20.12 6 0.09, P = 0.15 for men; and b = 20.14 6 0.05, P = 0.005 for women). Moreover, plasma ferritin levels decreased with increasing tertile of leg fat mass among each tertile of trunk fat mass. Conclusion: This is the first study to report the opposite associations of trunk and leg fat depots with plasma ferritin levels