Three Cardinal Lessons from ADAPT - 10 Years on

The Alzheimer's Disease Anti-inflammatory Prevention Trial was a placebo-controlled three-arm pharmaco-prevention trial of the non-steroidal anti-inflammatory drugs naproxen sodium and celecoxib for prevention of incident Alzheimer's disease (AD) dementia in older (aged 70 and over) adults. Although subjects were at increased risk of symptoms because of a firstdegree family history, they were meant to be cognitively healthy at enrollment. ADAPT encountered several problems that resulted in the termination of its treatments after only two years on average. Interim results were complex but potentially interesting. In the end, however, the results were null. We describe the complications that prevented ADAPT from achieving conclusive results, and suggest that these could have been avoided if the trial design and execution had been better guided by preliminary data. We believe such data should be available before beginning further ambitious phase III trials of this sort, and we suggest a broad method by which such data can be accumulated with reasonable economy.

A hierarchy of predictors for dementia-free survival in old-age: results of the AgeCoDe study

OBJECTIVE

Progression from cognitive impairment (CI) to dementia is predicted by several factors, but their relative importance and interaction are unclear.

METHOD

We investigated numerous such factors in the AgeCoDe study, a longitudinal study of general practice patients aged 75+. We used recursive partitioning analysis (RPA) to identify hierarchical patterns of baseline covariates that predicted dementia-free survival.

RESULTS

Among 784 non-demented patients with CI, 157 (20.0%) developed dementia over a follow-up interval of 4.5 years. RPA showed that more severe cognitive compromise, revealed by a Mini-Mental State Examination (MMSE) score < 27.47, was the strongest predictor of imminent dementia. Dementia-free survival time was shortest (mean 2.4 years) in such low-scoring patients who also had impaired instrumental activities of daily living (iADL) and subjective memory impairment with related worry (SMI-w). Patients with identical characteristics but without SMI-w had an estimated mean dementia-free survival time of 3.8 years, which was still shorter than in patients who had subthreshold MMSE scores but intact iADL (4.2-5.2 years).

CONCLUSION

Hierarchical patterns of readily available covariates can predict dementia-free survival in older general practice patients with CI. Although less widely appreciated than other variables, iADL impairment appears to be an especially noteworthy predictor of progression to dementia.

The association of psychotropic medication use with the cognitive, functional, and neuropsychiatric trajectory of Alzheimer's disease

OBJECTIVE

The use of psychotropic medications in Alzheimer's disease (AD) has been associated with both deleterious and potentially beneficial outcomes. We examined the longitudinal association of psychotropic medication use with cognitive, functional, and neuropsychiatric symptom (NPS) trajectories among community-ascertained incident AD cases from the Cache County Dementia Progression Study.

METHODS

A total of 230 participants were followed for a mean of 3.7 years. Persistency index (PI) was calculated for all antidepressants, selective serotonin reuptake inhibitors (SSRIs), antipsychotics (atypical and typical), and benzodiazepines as the proportion of observed time of medication exposure. Mixed-effects models were used to examine the association between PI for each medication class and Mini-Mental State Exam (MMSE), Clinical Dementia Rating Sum of Boxes (CDR-Sum), and Neuropsychiatric Inventory - Total (NPI-Total) trajectories, controlling for appropriate demographic and clinical covariates.

RESULTS

At baseline, psychotropic medication use was associated with greater severity of dementia and poorer medical status. Higher PI for all medication classes was associated with a more rapid decline in MMSE. For antidepressant, SSRI, benzodiazepine, and typical antipsychotic use, a higher PI was associated with a more rapid increase in CDR-Sum. For SSRIs, antipsychotics, and typical antipsychotics, a higher PI was associated with more rapid increase in NPI-Total.

CONCLUSIONS

Psychotropic medication use was associated with more rapid cognitive and functional decline in AD, and not with improved NPS. Clinicians may tend to prescribe psychotropic medications to AD patients at risk of poorer outcomes, but one cannot rule out the possibility of poorer outcomes being caused by psychotropic medications.

Nonsteroidal anti-inflammatory drugs are associated with increased neuritic plaques

OBJECTIVES

Observational and experimental studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) may protect against Alzheimer disease (AD); however, clinical trials and other observational studies, including the Adult Changes in Thought (ACT) study, show no protection or promotion of AD. The objective of this study is to determine the relationship between common dementia-associated pathologies and mid- to late-life NSAID exposure.

METHODS

We examined the association of mid- to late-life NSAID use with neuropathologic findings on 257 autopsies from ACT, a population-based study of brain aging and incident dementia. Cumulative standard daily doses (SDD) of nonselective NSAIDs were determined from ≥10 years of computerized pharmacy dispensing data. Analyses were adjusted for selection bias to broaden generalizability of results to 3,026 eligible participants in the ACT cohort. Seven pathologic indices were evaluated: intermediate or frequent score for neuritic plaques, Braak stages V or VI for neurofibrillary tangles, >2 cerebral microinfarcts, the presence of any neocortical Lewy bodies, any macroscopic infarcts, any amyloid angiopathy, and moderate or severe atherosclerosis.

RESULTS

Of the neuropathologic indices evaluated, only neuritic plaque score was significantly increased in participants with greater use of nonselective NSAIDs (p = 0.065), specifically in those with high levels of cumulative use: 1,000-2,000 SDD (adjusted relative risk [RR] 2.16, 95% confidence interval [CI] 1.02-4.25, compared to light/nonuse [<60 SDD]) and >2,000 SDD (adjusted RR 2.37, 95% CI 1.24-4.67).

CONCLUSIONS

Increased neuritic plaque accumulation may explain the association between heavy use of nonselective NSAIDs and increased risk of dementia among ACT participants.

Occupational exposure to pesticides increases the risk of incident AD: the Cache County study

BACKGROUND

Commonly used organophosphate and organochlorine pesticides inhibit acetylcholinesterase at synapses in the somatic, autonomic, and central nervous systems and may therefore have lasting effects on the nervous system. Few studies have examined the relationship of pesticide exposure and risk of dementia or Alzheimer disease (AD). We sought to examine the association of occupational pesticide exposure and the risk of incident dementia and AD in later life.

METHODS

Residents of the agricultural community of Cache County, UT, who were aged 65 years and older as of January 1995, were invited to participate in the study. At baseline, participants completed detailed occupational history questionnaires that included information about exposures to various types of pesticides. Cognitive status was assessed at baseline and after 3, 7, and 10 years. Standardized methods were used for detection and diagnosis of dementia and AD. Cox proportional hazards survival analyses were used to evaluate the risk of incident dementia and AD associated with pesticide exposure.

RESULTS

Among 3,084 enrollees without dementia, more men than women reported pesticide exposure (p < 0.0001). Exposed individuals (n = 572) had more years of education (p < 0.01) but did not differ from others in age. Some 500 individuals developed incident dementia, 344 with AD. After adjustment for baseline age, sex, education, APOE epsilon4 status, and baseline Modified Mini-Mental State Examination scores, Cox proportional hazards models showed increased risks among pesticide-exposed individuals for all-cause dementia, with hazard ratio (HR) 1.38 and 95% confidence interval (CI) 1.09-1.76, and for AD (HR 1.42, 95% CI 1.06-1.91). The risk of AD associated with organophosphate exposure (HR 1.53, 95% CI 1.05-2.23) was slightly higher than the risk associated with organochlorines (HR 1.49, 95% CI 0.99-2.24), which was nearly significant.

CONCLUSIONS

Pesticide exposure may increase the risk of dementia and Alzheimer disease in late life.

Identification of VaD and AD prodromes: the Cache County Study

BACKGROUND

It is unclear whether vascular dementia (VaD) has a cognitive prodrome, akin to the mild cognitive impairment (MCI) prodrome to Alzheimer's dementia (AD). To evaluate whether VaD has a cognitive prodrome, and if it can be differentiated from prodromal AD, we examined neuropsychological test performance of participants in a nested case-control study within a population-based cohort aged 65 or older.

METHODS

Participants (n = 485) were identified from the Cache County Study, a large population-based study of aging and dementia. After an average of 3 years of follow-up, a total of 62 incident dementia cases were identified (14 VaD, 48 AD). We identified a number of neuropsychological tests (executive and memory) that discriminated between diagnosed VaD and AD cases. Multivariate analyses sought to differentiate between these same groups 3 years before clinical diagnosis.

RESULTS

The Consortium to Establish a Registry for Alzheimer's Disease Word List Recognition Test correct recognition of foils (mean difference, 1.25; 95% confidence interval [CI], 0.42 to 2.07; p < 0.01), Logical Memory I (mean difference, 7.16; 95% CI, 0.78 to 13.55, p < 0.05), Logical Memory II delayed recall (mean difference, 8.67; 95% CI, 1.59 to 15.74, p < 0.05), and percent savings (mean difference, 51.07; 95% CI, 32.58 to 69.56, p < 0.0001) differentiated VaD from AD cases after adjustment for age, sex, education, and dementia severity. Three years before dementia diagnosis, word list recognition ("no" responses mean difference, 1.40; 95% CI, 0.64 to 2.17; p < 0.001, and "yes" responses mean difference, -1.14; 95% CI, -2.14 to -0.13; p < 0.03) discriminated between prodromal VaD and AD.

CONCLUSION

These results suggest that VaD has a prodromal syndrome, the cognitive features of which are distinguishable from the cognitive prodrome of AD.

Twin pairs discordant for neuropathologically confirmed Lewy body dementia

AIM

Little is known about the concordance rate in twins for dementia with Lewy bodies (DLB). The rate of agreement between clinical and pathological diagnoses for DLB is typically low, necessitating confirmation of the diagnosis neuropathologically.

METHODS

Participants were 17 twin pairs enrolled in the Duke Twins Study of Memory in Aging in which at least one member of the pair had an autopsy confirmed diagnosis of DLB, Alzheimer's disease (AD) with Lewy bodies or frontotemporal dementia with Lewy bodies. The characteristics of those with dementia were assessed and rates of concordance for pathological confirmed dementia were examined.

RESULTS

Four monozygotic twin pairs had a proband with neuropathologically confirmed pure DLB; all remained discordant for dementia for periods up to 16 years or more. Five of 13 pairs in which the proband had AD plus DLB were concordant for dementia but only one pair was concordant for AD plus DLB, while the co-twins in the other four pairs had other types of dementia.

CONCLUSIONS

The present study indicates that even among twins, a diagnosis of DLB in one twin does not predict the same diagnosis in the other twin. Neuropathological discordance in type of dementia among monozygotic pairs hints at environmental or epigenetic factors playing a role in Lewy body pathology.

Risk of dementia and AD with prior exposure to NSAIDs in an elderly community-based cohort

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) may prevent Alzheimer dementia (AD).

METHODS

We analyzed the association of prior NSAID exposure with incident dementia and AD in the Adult Changes in Thought population-based cohort aged > or = 65 years (median 74.8) at enrollment. Participants were members of Group Health, which provided computerized pharmacy dispensing records from 1977 onward. We studied 2,736 dementia-free enrollees with extensive prior pharmacy data, following them biennially for up to 12 years to identify dementia and AD. Cox proportional hazards regression assessed association of dementia or AD with NSAID use graded in standard daily doses (SDD) dispensed over 2 years (e.g., heavy use = 500 + SDD), with some analyses also adding consecutive biennial self-reports of NSAID use.

RESULTS

Pharmacy records identified 351 participants (12.8%) with history of heavy NSAID use at enrollment. Another 107 became heavy users during follow-up. Some 476 individuals developed incident dementia, 356 with AD (median onset ages 83.5 and 83.8 years). Contrary to the hypothesis that NSAIDs protect against AD, pharmacy-defined heavy NSAID users showed increased incidence of dementia and AD, with adjusted hazard ratios of 1.66 (95% confidence interval, 1.24-2.24) and 1.57 (95% confidence interval, 1.10-2.23). Addition of self-reported exposure data did not alter these results.

CONCLUSIONS

These findings differ from those of other studies with younger cohorts. The results observed elsewhere may reflect delayed onset of Alzheimer dementia (AD) in nonsteroidal anti-inflammatory drug (NSAID) users. Conceivably, such delay could result in increased AD incidence in late old age. The relation of NSAID use and AD pathogenesis needs further investigation.

No advantage of A beta 42-lowering NSAIDs for prevention of Alzheimer dementia in six pooled cohort studies

INTRODUCTION

Observational studies show reduced incidence of Alzheimer dementia (AD) in users of nonsteroidal anti-inflammatory drugs (NSAIDs). One hypothesis holds that the subset of NSAIDs known as selective A beta(42)-lowering agents (SALAs) is responsible for this apparent reduction in AD risk.

METHODS

We pooled individual-level data from six prospective studies to obtain a sufficient sample to examine AD risk in users of SALA vs non-SALA NSAIDs.

RESULTS

Of 13,499 initially dementia-free participants (70,863 person-years), 820 developed incident AD. Users of NSAIDs (29.6%) showed reduced risk of AD (adjusted hazard ratio [aHR] 0.77, 95% CI 0.65-0.91). The point estimates were similar for SALAs (aHR 0.87, CI 0.72-1.04) and non-SALAs (aHR 0.75, CI 0.56-1.01). Because 573 NSAID users (14.5%) reported taking both a SALA and non-SALA, we examined their use alone and in combination. Resulting aHRs were 0.82 (CI 0.67-0.99) for SALA only, 0.60 (CI 0.40-0.90) for non-SALA only, and 0.87 (CI 0.57-1.33) for both NSAIDs (Wald test for differences, p = 0.32). The 40.7% of participants who used aspirin also showed reduced risk of AD, even when they used no other NSAIDs (aHR 0.78, CI 0.66-0.92). By contrast, there was no association with use of acetaminophen (aHR 0.93, CI 0.76-1.13).

CONCLUSIONS

In this pooled dataset, nonsteroidal anti-inflammatory drug (NSAID) use reduced the risk of Alzheimer dementia (AD). However, there was no apparent advantage in AD risk reduction for the subset of NSAIDs shown to selectively lower A beta(42), suggesting that all conventional NSAIDs including aspirin have a similar protective effect in humans.

Vascular factors predict rate of progression in Alzheimer disease

BACKGROUND

While there is considerable epidemiologic evidence that cardiovascular risk factors increase risk of incident Alzheimer disease (AD), few studies have examined their effect on progression after an established AD diagnosis.

OBJECTIVE

To examine the effect of vascular factors, and potential age modification, on rate of progression in a longitudinal study of incident dementia.

METHODS

A total of 135 individuals with incident AD, identified in a population-based sample of elderly persons in Cache County, UT, were followed with in-home visits for a mean of 3.0 years (range: 0.8 to 9.5) and 2.1 follow-up visits (range: 1 to 5). The Clinical Dementia Rating (CDR) Scale and Mini-Mental State Examination (MMSE) were administered at each visit. Baseline vascular factors were determined by interview and physical examination. Generalized least-squares random-effects regression was performed with CDR Sum of Boxes (CDR-Sum) or MMSE as the outcome, and vascular index or individual vascular factors as independent variables.

RESULTS

Atrial fibrillation, systolic hypertension, and angina were associated with more rapid decline on both the CDR-Sum and MMSE, while history of coronary artery bypass graft surgery, diabetes, and antihypertensive medications were associated with a slower rate of decline. There was an age interaction such that systolic hypertension, angina, and myocardial infarction were associated with greater decline with increasing baseline age.

CONCLUSION

Atrial fibrillation, hypertension, and angina were associated with a greater rate of decline and may represent modifiable risk factors for secondary prevention in Alzheimer disease. The attenuated decline for diabetes and coronary artery bypass graft surgery may be due to selective survival. Some of these effects appear to vary with age.

Prevention of Alzheimer's disease

The already considerable public health burden of Alzheimer's disease will likely worsen as populations around the world age. As a result, there is considerable motivation to develop effective strategies for preventing the disease. A wide variety of such strategies are under investigation and include pharmaceuticals, nutriceuticals, diet, physical activity and cognitive activity. We review here the most promising candidates and the epidemiologic evidence for their efficacy. Although none of these have yet to be definitively shown to prevent Alzheimer's disease, further research should help to clarify what role they may play in reducing the burden of this disease.

NSAID use and dementia risk in the Cardiovascular Health Study: role of APOE and NSAID type

BACKGROUND

Epidemiologic and laboratory studies suggest that nonsteroidal antiinflammatory drugs (NSAIDs) reduce risk of Alzheimer disease (AD). We therefore investigated the association between use of NSAIDs, aspirin, and the non-NSAID analgesic acetaminophen with incidence of dementia and AD.

METHODS

Participants in the Cardiovascular Health Cognition Study included 3,229 individuals aged 65 or older, free of dementia at baseline, with information on medication use. We used Cox proportional hazards regression to estimate the association of medication use with incident all-cause dementia, AD, and vascular dementia (VaD). Additional analyses considered the NSAID-AD relationship as a function of age, presence of at least one epsilon 4 allele at APOE, race, and individual NSAIDs' reported ability to reduce production of the amyloid-beta peptide variant A beta(42).

RESULTS

Use of NSAIDs was associated with a lower risk of dementia (adjusted hazard ratio or aHR 0.76, 95% CI or CI 0.60-0.96) and, in particular, AD (aHR 0.63, CI 0.45-0.88), but not VaD (aHR 0.92, CI 0.65-1.28). No similar trends were observed with acetaminophen (aHR 0.99, CI 0.79-1.24). Closer examination suggested AD risk reduction with NSAIDs only in participants having an APOE epsilon 4 allele (aHR 0.34, CI 0.18-0.65; aHR for others 0.88, CI 0.59-1.32). There was no advantage in AD risk reduction with NSAIDs reported to selectively reduce A beta(42).

CONCLUSIONS

Results were consistent with previous cohort studies showing reduced risk of AD in NSAID users, but this association was found only in those with an APOE epsilon 4 allele, and there was no advantage for A beta(42)-lowering NSAIDs.

Intranasal insulin improves cognition and modulates beta-amyloid in early AD

BACKGROUND

Reduced brain insulin signaling and low CSF-to-plasma insulin ratios have been observed in patients with Alzheimer disease (AD). Furthermore, intracerebroventricular or IV insulin administration improve memory, alter evoked potentials, and modulate neurotransmitters, possibly by augmenting low brain levels. After intranasal administration, insulin-like peptides follow extracellular pathways to the brain within 15 minutes.

OBJECTIVE

We tested the hypothesis that daily intranasal insulin treatment would facilitate cognition in patients with early AD or its prodrome, amnestic mild cognitive impairment (MCI). The proportion of verbal information retained after a delay period was the planned primary outcome measure. Secondary outcome measures included attention, caregiver rating of functional status, and plasma levels of insulin, glucose, beta-amyloid, and cortisol.

METHODS

Twenty-five participants were randomly assigned to receive either placebo (n = 12) or 20 IU BID intranasal insulin treatment (n = 13) using an electronic atomizer, and 24 participants completed the study. Participants, caregivers, and all clinical evaluators were blinded to treatment assignment. Cognitive measures and blood were obtained at baseline and after 21 days of treatment.

RESULTS

Fasting plasma glucose and insulin were unchanged with treatment. The insulin-treated group retained more verbal information after a delay compared with the placebo-assigned group (p = 0.0374). Insulin-treated subjects also showed improved attention (p = 0.0108) and functional status (p = 0.0410). Insulin treatment raised fasting plasma concentrations of the short form of the beta-amyloid peptide (A beta 40; p = 0.0471) without affecting the longer isoform (A beta 42), resulting in an increased A beta 40/42 ratio (p = 0.0207).

CONCLUSIONS

The results of this pilot study support further investigation of the benefits of intranasal insulin for patients with Alzheimer disease, and suggest that intranasal peptide administration may be a novel approach to the treatment of neurodegenerative disorders.

Statin therapy is associated with reduced neuropathologic changes of Alzheimer disease

BACKGROUND

Treatment with 3-hydroxy-3-methylglutaryl-coenzyme-A reductase inhibitors ("statins") has been associated in some epidemiologic studies with reduced risk of Alzheimer disease (AD). However, direct evidence of statin effects on neuropathologic markers of AD is lacking. We investigated whether antecedent statin exposure is associated with neuritic plaque (NP) or neurofibrillary tangle (NFT) burden in a population-based sample of human subjects.

METHODS

Brain autopsies were performed on 110 subjects, ages 65 to 79 years, who were cognitively normal at enrollment into the Adult Changes in Thought Study. Neuropathologic findings were compared between statin users with > or =3 prescriptions of > or =15 pills of simvastatin, pravastatin, lovastatin, or atorvastatin vs nonusers, based on pharmacy dispensing records.

RESULTS

After controlling for age at death, gender, cognitive function at study entry, brain weight, and presence of cerebral microvascular lesions, the odds ratio (OR) for each unit increase in Braak NFT stage in statin users vs nonusers was 0.44 (95% CI: 0.20 to 0.95). The OR for each unit increase in Consortium to Establish a Registry for Alzheimer's Disease (CERAD) staging of NPs did not deviate significantly from unity (OR 0.69; 95% CI: 0.32 to 1.52). However, the risk for typical AD pathology (Braak stage > or = IV and CERAD rating > or = moderate) was reduced in statin users (OR 0.20; 95% CI: 0.05 to 0.86).

CONCLUSIONS

These findings demonstrate an association between antecedent statin use and neurofibrillary tangle burden at autopsy. Additional study is needed to examine whether statin use may be causally related to decreased development of Alzheimer disease-related neuropathologic changes.

Does NSAID use modify cognitive trajectories in the elderly?: The Cache County Study

BACKGROUND

Epidemiologic studies have suggested that nonsteroidal anti-inflammatory drugs (NSAIDs) may be useful for the prevention of Alzheimer disease (AD). By contrast, clinical trials have not supported NSAID use to delay or treat AD. Few studies have evaluated cognitive trajectories of NSAID users over time.

METHODS

Residents of Cache County, UT, aged 65 or older on January 1, 1995, were invited to participate in the study. At baseline, participants provided a detailed inventory of their medications and completed a revised Modified Mini-Mental State Examination (3MS). Participants (n = 3,383) who were cognitively normal at baseline were re-examined after 3 and 8 years. The association between NSAID use and 3MS scores over time was estimated using random effects modeling.

RESULTS

Associations depended upon when NSAIDs were started and APOE genotype. In participants who started NSAID use prior to age 65, those with no APOE epsilon4 alleles performed similarly to nonusers (a difference of 0.10 points per year; p = 0.19), while those with one or more epsilon4 allele(s) showed more protection (0.40 points per year; p = 0.0005). Among participants who first used NSAIDs at or after age 65, those with one or more epsilon4 alleles had higher baseline scores (0.95 points; p = 0.03) but did not show subsequent difference in change in score over time (0.06 points per year; p = 0.56). Those without an epsilon4 allele who started NSAID use after age 65 showed greater decline than nonusers (-0.16 points per year; p = 0.02).

CONCLUSIONS

Nonsteroidal anti-inflammatory drug use may help to prevent cognitive decline in older adults if started in midlife rather than late life. This effect may be more notable in those who have one or more APOE epsilon4 alleles.

Antioxidant intake and cognitive function of elderly men and women: the Cache County Study

OBJECTIVE

We prospectively examined associations between intakes of antioxidants (vitamins C, vitamin E, and carotene) and cognitive function and decline among elderly men and women of the Cache County Study on Memory and Aging in Utah.

PARTICIPANTS AND DESIGN

In 1995, 3831 residents 65 years of age or older completed a baseline survey that included a food frequency questionnaire and cognitive assessment. Cognitive function was assessed using an adapted version of the Modified Mini-Mental State examination (3MS) at baseline and at three subsequent follow-up interviews spanning approximately 7 years. Multivariable-mixed models were used to estimate antioxidant nutrient effects on average 3MS score over time.

RESULTS

Increasing quartiles of vitamin C intake alone and combined with vitamin E were associated with higher baseline average 3MS scores (p-trend = 0.013 and 0.02 respectively); this association appeared stronger for food sources compared to supplement or food and supplement sources combined. Study participants with lower levels of intake of vitamin C, vitamin E and carotene had a greater acceleration of the rate of 3MS decline over time compared to those with higher levels of intake.

CONCLUSION

High antioxidant intake from food and supplement sources of vitamin C, vitamin E, and carotene may delay cognitive decline in the elderly.

Naproxen and celecoxib do not prevent AD in early results from a randomized controlled trial

OBJECTIVE

To evaluate the efficacy and safety of naproxen and celecoxib for the primary prevention of Alzheimer disease (AD).

METHODS

Randomized, placebo-controlled, double-masked clinical trial conducted at six US dementia research clinics. Volunteers aged 70+ years, with cognitive screening scores above designated cut-offs and a family history of AD, were randomly assigned to celecoxib 200 mg BID, naproxen sodium 220 mg BID, or placebo. Enrollment began in early 2001. The main outcome measure was diagnosis of AD after randomization.

RESULTS

On December 17, 2004, treatments were suspended. Events while on treatment yielded hazard ratios vs placebo of 1.99 (95% CI 0.80 to 4.97; p = 0.14) for celecoxib and 2.35 (0.95 to 5.77; p = 0.06) for naproxen. Imperfect screening measures led to enrollment of 7 individuals with dementia and 46 others with milder cognitive syndromes. Their (prevalent) illness was detected at enrollment and diagnosed within 6 months following randomization. Secondary analyses that excluded the 7 cases of prevalent dementia showed increased hazard ratios for AD with both treatments. Neither treatment produced a notable effect on the incidence of milder cognitive syndromes.

CONCLUSIONS

These results do not support the hypothesis that celecoxib or naproxen prevent Alzheimer dementia, at least within the early years after initiation of treatment. Masked long-term follow-up of these participants will be essential.

Risk factors for neuropsychiatric symptoms in dementia: the Cache County Study

OBJECTIVE

To investigate the probability of individual neuropsychiatric symptoms in dementia patients as a function of eight risk factors.

METHODS

In the Cache County Study, we administered the Neuropsychiatric Inventory (NPI) to 328 dementia patients at baseline. Approximately 18 months later, we re-administered the NPI to 184 participants available for follow-up. Generalized estimating equation methods were used to model the probability of individual neuropsychiatric symptoms as a function of: gender, age, education, dementia type and severity, APOE status, time of observation, and general medical health.

RESULTS

Women showed increased tendency toward anxiety, [odds ratio (OR) 2.22, 95% confidence interval (CI) 1.31-3.76] and delusions (OR 2.15, CI 1.22-3.78), but older persons of both sexes showed less tendency toward anxiety. Dementia severity increased the tendency toward hallucinations and agitation (OR 2.42, CI 1.81-3.23) and decreased risk of depression. Positive APOE epsilon4 status increased the tendency toward aberrant motor behavior (OR 1.84, CI 1.05-3.22). Among dementia diagnoses, those with Alzheimer's disease showed decreased tendency toward agitation (OR 0.58, CI 0.35-0.95), depression (OR 0.56, CI 0.33-0.96) and disinhibition (OR 0.46, CI 0.24-0.88). Later time of observation increased risk of aberrant motor behavior and delusions, and more serious medical comorbidity increased risk of, agitation, irritability, disinhibition, and aberrant motor behavior.

CONCLUSIONS

Gender, age, dementia severity, APOE epsilon4, dementia diagnosis, time of observation, and general medical health appear to influence the occurrence of individual neuropsychiatric symptoms.

Conversion to dementia from mild cognitive disorder: the Cache County Study

OBJECTIVE

To examine 3-year rates of conversion to dementia, and risk factors for such conversion, in a population-based sample with diverse types of cognitive impairment.

METHODS

All elderly (aged 65 or older) residents of Cache County, UT, were invited to undergo two waves of dementia screening and assessment. Three-year follow-up data were available for 120 participants who had some form of mild cognitive impairment at baseline. Of these, 51 had been classified at baseline with prodromal Alzheimer disease (proAD), and 69 with other cognitive syndromes (CS).

RESULTS

Three-year rates of conversion to dementia were 46% among those with cognitive impairment at baseline. By comparison, 3.3% without impairment converted to dementia in the interval. Among converters, AD was the most common type of dementia. In individuals with at least one APOE epsilon4 allele, those with proAD or CS exhibited a 22- to 25-fold higher risk of dementia than cognitively unimpaired individuals (vs 5- to 10-fold higher risk in those without epsilon4).

CONCLUSIONS

Individuals with all types of mild cognitive impairment have an elevated risk of dementia over 3 years, more so in those with an APOE epsilon4 allele. These results suggest value in dementia surveillance for broad groups of cognitively impaired individuals beyond any specific category, and utility of APOE genotyping as a prognostic method.

Serum cholesterol and risk of Alzheimer disease: a community-based cohort study

OBJECTIVES

To examine the association of serum total cholesterol (TC) and high density lipoprotein (HDL) levels and subsequent incidence of dementia and Alzheimer disease (AD) in a population-based cohort study.

METHODS

A cohort of cognitively intact persons, aged 65 and older, was randomly selected from Group Health Cooperative (GHC), a large health maintenance organization, and was assessed biennially for dementia. Premorbid levels of TC and HDL were obtained from a computerized clinical laboratory database at GHC. Cox proportional hazards regression was used to calculate hazard ratios (HR, 95% CI) for dementia and AD associated with quartiles of TC and HDL levels.

RESULTS

Of the 2,356 eligible participants, 2,141 had at least one serum TC measure prior to the initial enrollment. Using the lowest TC quartiles as the reference group, the HR in the highest TC quartiles was not significantly elevated for dementia (1.16, 0.81 to 1.67) or for AD (1.00, 0.61 to 1.62) after adjusting for age, sex, education, baseline cognition, vascular comorbidities, body mass index, and lipid-lowering agent use. Serum HDL showed a similar lack of significant association with risk of dementia or AD. Models that included the presence of one or more APOE-epsilon4 alleles showed a typical association of epsilon4 with AD risk. This association was not materially modified by inclusion of TC level.

CONCLUSION

The data do not support an association between serum total cholesterol or high density lipoprotein in late life and subsequent risk of dementia or Alzheimer disease (AD). The increased risk of AD with APOE-epsilon4 is probably not mediated by serum total cholesterol levels.

Determinants of vascular dementia in the Cardiovascular Health Cognition Study

OBJECTIVE

The authors evaluated 3,375 participants without dementia at the time of MRI in 1991 to 1994 over 5.7 years for incident dementia and type of dementia.

METHODS

Incidence of and risk factors for vascular dementia (VaD) were measured using both pre-MRI and modified State of California Alzheimer's Disease Diagnostic and Treatment Centers (ADDTC) post-MRI review and further classified Alzheimer disease (AD) by the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria.

RESULTS

Approximately 44% (213) of 480 incident dementia cases were classified as possible or probable VaD by ADDTC. The incidence of VaD increased with age and was greater in blacks than whites. Risk factors for VaD included age, Modified Mini-Mental State Examination, high white matter grade, number of MRI infarcts, ventricular size, and history of stroke.

CONCLUSIONS

Vascular disease in the brain is prevalent among incident dementia cases. There is a substantial overlap between cases classified as Alzheimer disease by Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association and vascular dementia (VaD) by modified State of California Alzheimer's Disease Diagnostic and Treatment Centers criteria. The substantial contribution of vascular disease would be missed without inclusion of MRI. Treatment of risk factors for VaD could have an important impact on incidence of dementia.

Dementia: the leading predictor of death in a defined elderly population: the Cache County Study

OBJECTIVE

To examine the relative risk and population attributable risk (PAR) of death with dementia of varying type and severity and other risk factors in a population of exceptional longevity.

METHODS

Deaths were monitored over 5 years using vital statistics records and newspaper obituaries in 355 individuals with prevalent dementia and 4,328 without in Cache County, UT. Mean age was 83.3 (SD 7.0) years with dementia and 73.7 (SD 6.8) years without. History of coronary artery disease, hypertension, diabetes, and other life-shortening illness was ascertained from interviews.

RESULTS

Death certificates implicated dementia as an important cause of death, but other data suggested a stronger association. Adjusted Cox relative hazard and PAR of death were higher with dementia than with any other illness studied. Relative hazard of death with dementia was highest at ages 65 to 74, but the high prevalence of dementia after age 85 resulted in 27% PAR among the oldest old. Mortality increased substantially with severity of dementia. Alzheimer disease shortened survival time most dramatically in younger participants, but vascular dementia posed a greater mortality risk among the oldest old.

CONCLUSION

In this population, dementia was the strongest predictor of mortality, with a risk two to three times those of other life-shortening illnesses.

Apolipoprotein E genotype and major depression in a community of older adults. The Cache County Study

BACKGROUND

The role of allelic variation in APOE, the genetic locus for apolipoprotein E, in geriatric depression is poorly understood. There are conflicting reports as to an association between the epsilon4 allele and depression in late life.

METHOD

Using a community based study of non-demented elders in Cache County, Utah, that included many very old individuals, we examined the relationship between APOE and late-onset (age > 60) depression, with particular attention to possible age effects.

RESULTS

There was no overall association between APOE and depression. However, there was a significant interaction effect of APOE and age such that the relationship of late-onset depression with respect to presence of the epsilon4 allele was larger among those 80 and older compared with those below age 80. Consistent with previous studies, women were more likely to experience late-onset depression than men.

CONCLUSIONS

Because we excluded prevalent cases of dementia, this pattern of relative risk with age may reflect the appearance of depressive symptoms as a prodrome of Alzheimer's disease or vascular dementia. Longitudinal studies should help to confirm or refute this explanation of the data.

Incidence of AD may decline in the early 90s for men, later for women: The Cache County study

OBJECTIVES

To characterize the incidence of AD among the elderly population of Cache County, UT, noted for its longevity and high response rates; to explore sex differences; and to examine whether AD incidence plateaus or declines in extreme old age.

METHODS

Using a multistage screening process in 1998 and 1999, and re-examining 122 individuals who had been identified 3 years earlier as cognitively compromised but not demented, the authors found 185 individuals with incident dementia (123 with AD) among 3,308 participants who contributed 10,541 person-years of observation. Adjusting for nonresponse and screening sensitivity, the authors estimated the incidence of dementia and of AD for men and women in 3-year age intervals. Multivariate discrete time survival analysis was used to examine influences of age, sex, education, and genotype at APOE, as well as interactions of these factors.

RESULTS

The incidence of both dementia and AD increased almost exponentially until ages 85 to 90, but appeared to decline after age 93 for men and 97 for women. A statistical interaction between age and the presence of two APOE-epsilon 4 alleles indicated acceleration in onset of AD with this genotype; the interaction of age and one epsilon 4 suggested more modest acceleration. A statistical interaction of sex and age indicated greater incidence of AD in women than in men after age 85.

CONCLUSIONS

The incidence of AD in the Cache County population increased with advancing age, but then peaked and declined among the extremely old. The presence of APOE-epsilon 4 alleles accelerated onset of AD, but did not appreciably alter lifetime incidence apparent over a span of 100 years.