- Email: [email protected]
P1-196
Poster Presentations P1 random effects models and Conditional Autoregressive (CAR) models were estimated using Markov Chain Monte Carlo (MCMC) methods. Results: At ages 85⫹, county prevalence ranged from 19% to 72% for African Americans, 10% to 53% for non-Hispanic whites; at ages 65-84 for combined populations, from 1.4% to 5.9%. Unadjusted positive predictors included diabetes death rate (a measure of both prevalence and severity) (p⫽.007), heart disease death rate (p⫽.025), and percent: physically inactive (p⫽.072), ages 65⫹ who were African American (p⬍.001), and with less than high school education (p⬍.001). Significant adjusted positive predictors were diabetes death rate (p⫽.034), percent 65⫹ African American (p⫽.025), and percent less than high school (p⬍.001). County median income was a significant adjusted negative predictor (p⫽.006). Conclusions: Low prevalence counties are national retirement destinations; in-migrants in these counties have much more education and income than older South Carolinians, and fewer risk factors. Findings suggest that variation in AD risk factors may be associated with AD prevalence variation. Behavioral and socioeconomic AD risk factors vary widely across areas of the US. Results suggest a need for national AD surveillance. P1-196
AGE-SPECIFIC PREVALENCE OF ALZHEIMER’S DISEASE IN A U.S. STATE WITH HIGH POPULATION RISKS: IS SOUTH CAROLINA A HARBINGER OF FUTURE NATIONAL PREVALENCE?
Sarah B. Laditka, James N. Laditka, Carol B. Cornman, Candace N. Porter, Doroth R. Davis. University of South Carolina, Columbia, SC, USA. Contact e-mail: [email protected] Background: There is evidence that healthy lifestyles may reduce dementia risk, possibly including Alzheimer’s disease (AD), in part by avoiding vascular damage accompanying diabetes, hypertension, hyperlipidemia, obesity, and physical inactivity. South Carolina has about 1.04 million residents age 55⫹; 66,000 85⫹. Most are non-Hispanic whites or African Americans (30%). They have less education than the average older American, are more rural, and have notably high rates of vascular risk factors associated with dementia. We hypothesized that AD prevalence would be relatively high in South Carolina. Objectives: (1) To calculate age-specific AD prevalence; (2) to compare results with leading estimates; (3) to provide information relevant to national AD prevalence projections. Methods: We estimated age-specific AD prevalence using the statewide population-based South Carolina Alzheimer’s Disease Registry, maintained since 1988. The Registry uses data from medical care encounters, long-term care evaluations, the mental health system, adjacent states, and other sources, with one record for each case. Registry data for 2003, with over 31,000 individuals with AD (excluding other dementias), were combined with U.S. Census data to estimate prevalence. Age-specific rates were compared with results from studies commonly used to estimate national prevalence. Results: AD prevalence may be notably greater in South Carolina than in several age-specific national studies. Two exceptions are the East Boston study, and the Southern California study estimates that included Questionable AD. Conclusions: AD prevalence was greater at all ages in South Carolina than in several related studies. It is likely that the true prevalence of AD is higher than our estimates, as the Registry captures cases using services. A notable number of mild cases are unlikely to be captured. Lower educational attainment in SC may contribute to higher rates. Behavioral risks that far exceed the national average may also contribute notably. The United States’ population has rapidly increasing rates of lifestyle-related risk factors, and also growing minority populations with higher risks. Our results suggest that national prevalence projections should consider not only population aging, but also risk profiles associated with growing minority populations and lifestylerelated AD risks.
P1-197
S153
BORDERLINE DIABETES MELLITUS AND RISK OF DEMENTIA AND ALZHEIMER DISEASE: A POPULATION-BASED LONGITUDINAL STUDY
Weili Xu, Chengxuan Qiu, Bengt Winblad, Laura Fratiglioni. Karolinska Institutet, Stockholm, Sweden. Contact e-mail: [email protected] Background: Borderline diabetes mellitus has been linked to cognitive deficits in several studies, but no studies have explored the relationship between borderline diabetes mellitus and risk of dementia. We sought to examine the hypothesis that borderline diabetes mellitus is a risk factor for dementia and Alzheimer disease. Methods: A communitybased cohort of 1173 demented- and diabetes-free individuals aged ⱖ75 years in Stockholm, Sweden was longitudinally examined 3 times over a 9-year period to detect patients with dementia and Alzheimer disease using the DSM-III-R diagnostic criteria. Borderline diabetes mellitus was defined as a causal plasma glucose level between 7.8 and 11.0 mmol/L. Data were analyzed using Cox proportional-hazards models with adjustment for potential confounders. Results: During the 6076 person-years of follow-up (mean per person, 5.02 years), 397 subjects were diagnosed with dementia, including 307 with Alzheimer disease. At baseline, borderline diabetes mellitus was identified in 47 subjects. Overall, borderline diabetes mellitus resulted in multi-adjusted hazard ratios (95% confidence intervals) of 1.67 (1.04-2.67) for dementia and 1.77 (1.06-2.97) for Alzheimer disease. Stratified analysis suggested that such a significant association was present only among non-carriers of APOE ⑀4 allele. There was a significant interaction between borderline diabetes mellitus and severe systolic hypertension on the risk of dementia and Alzheimer disease. Conclusion: Borderline diabetes mellitus is associated with an increased risk of dementia and Alzheimer disease in the elderly. The risk for dementia and Alzheimer disease is especially high when borderline diabetes mellitus occurs together with severe systolic hypertension.
P1-198
CORTICAL ACETYLCHOLINE ESTERASE ACTIVITY, GLUCOSE METABOLISM, AND APOE4-GENOTYPE IN ALZHEIMER DISEASE: A PET STUDY
Carsten Eggers1, Karl Herholz2,1, Elke Kalbe1, Wolf D. Heiss3,1. 1 Department of Neurology, Cologne, Germany; 2Wolfson Molecular Imaging Centre, University of Manchester, United Kingdom; 3Max Planck-Institute for Neurological Research, Cologne, Germany. Contact e-mail: [email protected] Background: PET studies demonstrated reduced regional cerebral glucose metabolic rate (CMRGlc) and reduced cortical activity of acetylcholine esterase (AChE) as indicators of functional impairment in
AGE-SPECIFIC PREVALENCE OF ALZHEIMER’S DISEASE IN A U.S. STATE WITH HIGH POPULATION RISKS: IS SOUTH CAROLINA A HARBINGER OF FUTURE NATIONAL PREVALENCE?
Sarah B. Laditka, James N. Laditka, Carol B. Cornman, Candace N. Porter, Doroth R. Davis. University of South Carolina, Columbia, SC, USA. Contact e-mail: [email protected] Background: There is evidence that healthy lifestyles may reduce dementia risk, possibly including Alzheimer’s disease (AD), in part by avoiding vascular damage accompanying diabetes, hypertension, hyperlipidemia, obesity, and physical inactivity. South Carolina has about 1.04 million residents age 55⫹; 66,000 85⫹. Most are non-Hispanic whites or African Americans (30%). They have less education than the average older American, are more rural, and have notably high rates of vascular risk factors associated with dementia. We hypothesized that AD prevalence would be relatively high in South Carolina. Objectives: (1) To calculate age-specific AD prevalence; (2) to compare results with leading estimates; (3) to provide information relevant to national AD prevalence projections. Methods: We estimated age-specific AD prevalence using the statewide population-based South Carolina Alzheimer’s Disease Registry, maintained since 1988. The Registry uses data from medical care encounters, long-term care evaluations, the mental health system, adjacent states, and other sources, with one record for each case. Registry data for 2003, with over 31,000 individuals with AD (excluding other dementias), were combined with U.S. Census data to estimate prevalence. Age-specific rates were compared with results from studies commonly used to estimate national prevalence. Results: AD prevalence may be notably greater in South Carolina than in several age-specific national studies. Two exceptions are the East Boston study, and the Southern California study estimates that included Questionable AD. Conclusions: AD prevalence was greater at all ages in South Carolina than in several related studies. It is likely that the true prevalence of AD is higher than our estimates, as the Registry captures cases using services. A notable number of mild cases are unlikely to be captured. Lower educational attainment in SC may contribute to higher rates. Behavioral risks that far exceed the national average may also contribute notably. The United States’ population has rapidly increasing rates of lifestyle-related risk factors, and also growing minority populations with higher risks. Our results suggest that national prevalence projections should consider not only population aging, but also risk profiles associated with growing minority populations and lifestylerelated AD risks.
P1-197
S153
BORDERLINE DIABETES MELLITUS AND RISK OF DEMENTIA AND ALZHEIMER DISEASE: A POPULATION-BASED LONGITUDINAL STUDY
Weili Xu, Chengxuan Qiu, Bengt Winblad, Laura Fratiglioni. Karolinska Institutet, Stockholm, Sweden. Contact e-mail: [email protected] Background: Borderline diabetes mellitus has been linked to cognitive deficits in several studies, but no studies have explored the relationship between borderline diabetes mellitus and risk of dementia. We sought to examine the hypothesis that borderline diabetes mellitus is a risk factor for dementia and Alzheimer disease. Methods: A communitybased cohort of 1173 demented- and diabetes-free individuals aged ⱖ75 years in Stockholm, Sweden was longitudinally examined 3 times over a 9-year period to detect patients with dementia and Alzheimer disease using the DSM-III-R diagnostic criteria. Borderline diabetes mellitus was defined as a causal plasma glucose level between 7.8 and 11.0 mmol/L. Data were analyzed using Cox proportional-hazards models with adjustment for potential confounders. Results: During the 6076 person-years of follow-up (mean per person, 5.02 years), 397 subjects were diagnosed with dementia, including 307 with Alzheimer disease. At baseline, borderline diabetes mellitus was identified in 47 subjects. Overall, borderline diabetes mellitus resulted in multi-adjusted hazard ratios (95% confidence intervals) of 1.67 (1.04-2.67) for dementia and 1.77 (1.06-2.97) for Alzheimer disease. Stratified analysis suggested that such a significant association was present only among non-carriers of APOE ⑀4 allele. There was a significant interaction between borderline diabetes mellitus and severe systolic hypertension on the risk of dementia and Alzheimer disease. Conclusion: Borderline diabetes mellitus is associated with an increased risk of dementia and Alzheimer disease in the elderly. The risk for dementia and Alzheimer disease is especially high when borderline diabetes mellitus occurs together with severe systolic hypertension.
P1-198
CORTICAL ACETYLCHOLINE ESTERASE ACTIVITY, GLUCOSE METABOLISM, AND APOE4-GENOTYPE IN ALZHEIMER DISEASE: A PET STUDY
Carsten Eggers1, Karl Herholz2,1, Elke Kalbe1, Wolf D. Heiss3,1. 1 Department of Neurology, Cologne, Germany; 2Wolfson Molecular Imaging Centre, University of Manchester, United Kingdom; 3Max Planck-Institute for Neurological Research, Cologne, Germany. Contact e-mail: [email protected] Background: PET studies demonstrated reduced regional cerebral glucose metabolic rate (CMRGlc) and reduced cortical activity of acetylcholine esterase (AChE) as indicators of functional impairment in