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Lon White

Publications and source records attributed to Lon White.

12 recordsLinked to original sources
PubMed2006

The effect of social engagement on incident dementia: the Honolulu-Asia Aging Study.

The authors examined whether low levels of social engagement in midlife and late life were associated with the risk of incident dementia in 2,513 Japanese-American men who have been followed since 1965 as part of the Honolulu Heart Program and the Honolulu-Asia Aging Study. In 1991, assessment of dementia began; incident dementia cases (n = 222) were diagnosed in 1994 and 1997. Social engagement was assessed in midlife (1968) and late life (1991). The relation between social engagement and dementia risk was examined using Cox proportional hazards models. No level of midlife social engagement was associated with the risk of dementia. In late life, compared with participants in the highest quartile of late-life social engagement, those in the lowest quartile had a significantly increased risk of dementia (hazard ratio = 2.34, 95% confidence interval: 1.18, 4.65). However, compared with those who were in the highest quartile of social engagement at both midlife and late life, only decreased social engagement from midlife to late life was associated with an increased risk of dementia (hazard ratio = 1.87, 95% confidence interval: 1.12, 3.13). Although low social engagement in late life is associated with risk of dementia, levels of late-life social engagement may already have been modified by the dementing process and may be associated with prodromal dementia.

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PubMed2005

Correlates of hippocampal neuron number in Alzheimer's disease and ischemic vascular dementia.

The cornu ammonis 1 region of the hippocampus (CA1) sector of hippocampus is vulnerable to both Alzheimer's disease (AD)-type neurofibrillary degeneration and anoxia-ischemia. The objective of this article is to compare number and size of neurons in CA1 in AD versus ischemic vascular dementia. Unbiased stereological methods were used to estimate the number and volume of neurons in 28 autopsy-derived brain samples. For each case, the entire hippocampus from one cerebral hemisphere was sliced into 5mm slabs (5-7 slabs/case), cut into 50 microm sections, and stained with gallocyanine. Using the optical dissector, we systematically sampled the number and size of neurons throughout the extent of CA1 and CA2. The total number of neurons was significantly less in AD compared with ischemic vascular dementia (p < 0.02), but there was no significant difference in neuron size. The greatest loss of neurons was observed in two cases with combined AD and hippocampal sclerosis. Regardless of causative diagnosis, the number of CA1 neurons correlates with magnetic resonance imaging-derived hippocampal volume (r = 0.72; p < 0.001) and memory score (r = 0.62; p < 0.01). We conclude that although CA1 neuron loss is more consistently observed in AD than ischemic vascular dementia, severity of loss shows the expected correlation with structure and function across causative subtype. Reductions in magnetic resonance imaging-derived hippocampal volume reflect loss, rather than shrinkage, of CA1 neurons.

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PubMed2005

Performance on the CERAD neuropsychology battery of two samples of Japanese-American elders: norms for persons with and without dementia.

Norms for cognitive measures used to assess dementia are scant for minority groups, in particular for older Japanese Americans. Using the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Neuropsychology Battery, we compared the baseline performance of demented and nondemented Japanese Americans. Participants came from two harmonized epidemiological studies of dementia which were examined separately: the Kame Project, Seattle (350 men and women; 201 nondemented), age 65 and older; Honolulu-Asia Aging Study (HAAS), Hawaii (418 men; 120 nondemented), age 71 and older. The measures examined were Verbal Fluency; abbreviated Boston Naming; constructional praxis; and Word List Learning, Recall, and Recognition. Within each study, the CERAD measures distinguished between nondemented participants and those with mild cognitive impairment. Among persons with dementia, average level of performance decreased as severity of dementia increased. Determinants of score (age, education, language of administration, stage of dementia) varied between the two studies. Among Japanese Americans, the CERAD Neuropsychology Battery distinguished nondemented persons from those with dementia, but was less consistent in distinguishing levels of severity of dementia. This battery is useful for comparative epidemiological studies of dementia in minority populations.

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PubMed2005

Recent clinical-pathologic research on the causes of dementia in late life: update from the Honolulu-Asia Aging Study.

In this study, we compare neuropathological findings at autopsy with clinical dementia diagnoses, such as Alzheimer's disease and vascular dementia. Participants consisted of 363 aged Japanese-American men from the Honolulu-Asia Aging Study. Results indicated that the correspondence between clinical and neuropathologic diagnosis was not great, with 56% of patients diagnosed with probable or possible Alzheimer's disease during life but with only 19% having neuritic plaques and/or neurofibrillary tangles as the sole or dominant dementia-related lesions in the brain at autopsy. Although 16% of cases were attributed to mixed causes during life, almost 40% were found to have significant mixtures of dementia-related lesions at autopsy. Finally, both Alzheimer's disease and non-Alzheimer's disease neuropathologic lesions contributed independently to the explanation of variance on a test of overall cognitive performance. The results suggest that clinical diagnosis of dementia made during life may fail to reflect the pathogenic complexity of this condition in very elderly persons.

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PubMed2003

Sleep-disordered breathing and cognitive impairment in elderly Japanese-American men.

STUDY OBJECTIVE: To assess the association between sleep-disordered breathing and cognitive functioning in an elderly cohort of Japanese-American men. DESIGN: Cross-sectional study. SETTING: The Honolulu-Asia Aging Study of Sleep Apnea, Oahu, Hawaii. PARTICIPANTS: 718 men between 79 and 97 years of age examined in 1999 and 2000. MEASUREMENTS: Apnea-hypopnea index from in-home overnight polysomnography, performance on the Cognitive Abilities Screening Instrument, body mass index, neck circumference, Epworth Sleepiness Scale, snoring, Center for Epidemiologic Studies Depression 11-item depression scale, physical disability, and history of heart disease, stroke, hypertension, diabetes, and dementia. RESULTS: Less than 30% of the men had no sleep-disordered breathing (apnea-hypopnea index < 5) and nearly one-fifth (19%) had severe sleep-disordered breathing (apnea-hypopnea index > or = 30). Severe sleep-disordered breathing was associated with higher body mass index, habitual snoring, and daytime drowsiness. No association was found between sleep-disordered breathing and cognitive functioning, including measures of memory function, concentration, and attention. CONCLUSIONS: Sleep-disordered breathing was associated with more drowsiness but not with poor performance on standardized cognitive tests used to screen for Alzheimer disease and other dementias in older persons. Because a healthy-participant effect may have contributed to this finding, more extensive cognitive testing may be necessary to reveal more subtle deficits from sleep-disordered breathing.

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PubMed2002

Cerebrovascular pathology and dementia in autopsied Honolulu-Asia Aging Study participants.

Clinicopathologic data from 285 autopsies were analyzed. The decedents were long-standing participants in the Honolulu-Asia Aging Study, a prospective epidemiologic investigation of stroke, neurodegenerative diseases, and aging. We assessed the prevalence at death of four primary neuropathologic processes using specific microscopic lesions as indicators. An algorithm was developed to assign each decedent to one of six subsets, corresponding to pathologic dominance by microvascular lesions (14% of decedents), Alzheimer lesions (12%), hippocampal sclerosis (5%), cortical Lewy bodies (5%), codominance by two or more primary processes (9%), or without a dominant pathologic process recognized (55%). Definite or probable dementia had been identified in 118 of the decedents. The proportions of men in each subset identified as demented were (in the same order) 57%, 53%, 79%, 57%, 76%, and 25%. In this autopsied panel of older Japanese-American men, the importance of microvascular lesions as a likely explanation for dementia was nearly equal to that of Alzheimer lesions. The cerebrovascular lesion type most essentially and inclusively related to dementia was multiple microinfarction.

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PubMed2002

Variability in midlife systolic blood pressure is related to late-life brain white matter lesions: the Honolulu-Asia Aging study.

BACKGROUND AND PURPOSE: Although white matter lesions (WMLs) on brain MRI in older persons are common, the mechanisms are unclear. Besides the associations with advanced age and high blood pressure (BP), variability in systolic BP (SBP) and the resulting changes in blood flow to the deep arteries of the brain may be contributing factors. METHODS: Japanese-American men in Hawaii have participated in a long-term study of cardiovascular disease, including midlife BP measurements at 3 clinical examinations in the period from 1965 to 1974. In the period from 1991 to 1993, dementia status was added to the fourth examination, and a brain MRI was completed in a fifth examination, which was from 1994 to 1996, on a subset of 575 men, who averaged 82 years. WMLs and ventricular atrophy were determined as the upper fifth in a standardized semiquantitative measure. Excess SBP variability was defined as greater than average increases in BP measurements from up to 3 examinations over 6 years. Logistic regression was used for the association of this variability with WMLs and atrophy, controlling for age, apolipoprotein E4 status, dementia diagnosis, and history of stroke. RESULTS: There were significant (2-fold) increased risks for WMLs among those with moderate and high SBP variability (third and fifth quintiles compared with the lowest quintile). Those in the highest SBP variability category (the fifth quintile) also had significantly more atrophy. CONCLUSIONS: These SBP variability-MRI relationships suggest that variation in SBP in midlife may be a contributing factor to the development of WMLs and ventricular atrophy in late life.

Age Factors↗
PubMed2002

Are depressive symptoms a risk factor for mortality in elderly Japanese American men?: the Honolulu-Asia Aging Study.

OBJECTIVE: This study determined the influence of depressive symptoms on subsequent mortality of all causes. METHOD: The Honolulu Heart Program, established in 1965, is a prospective, community-based cohort of Japanese American men living in Hawaii. The analysis was based on 3,196 Japanese American men aged 71-93 at the time of the fourth examination in 1991-1993. Depressive symptoms were measured by use of an 11-question version of the Centers for Epidemiologic Studies Depression Scale questionnaire. All-cause mortality data were available for 6 years of follow up. Data were analyzed on the basis of presence or absence of chronic diseases. RESULTS: The overall prevalence of frequent depressive symptoms was 9.9%. Age-adjusted mortality rates at 3 years were 48.0 and 30.3 per 1,000 person-years for the depressed and nondepressed groups, respectively. At 6 years, the rates were 54.1 (depressed) and 41.5 (nondepressed) per 1,000 person-years. After adjustment for age, marital status, and antidepressant use, the relative risk for all-cause mortality associated with depressive symptoms was 1.53 for 3-year and 1.27 for 6-year mortality. Among participants who were healthy (without cognitive impairment, coronary heart disease, stroke, diabetes, or cancer), the association between depressive symptoms and mortality was greater (relative risk of 2.30 and 1.57 for 3- and 6-year mortality, respectively). Among participants with chronic disease, there were no significant associations between depressive symptoms and mortality. CONCLUSIONS: Depressive symptoms are a risk factor for mortality in elderly people, particularly in physically healthy individuals.

Age Factors↗
PubMedDate not supplied

Reducing hospitalizations and arrests for substance abusers.

This four-year outcome study examines the results of the VA Contracted Residential Substance Abuse Treatment for veterans with substance abuse problems. Race, marital status, housing status, and exposure to combat in the military characterized the male veteran subjects. Hospitalization rates and arrest rates were tracked for two years prior to and two years post-residential treatment. The authors also examined treatment outcomes for those who completed outpatient substance abuse treatment after an episode of residential care. This study shows a 30% reduction of hospitalizations and arrests following residential treatment. Those veterans who completed both residential and outpatient treatment had the best outcomes in terms of number of hospitalizations and arrests in a two-year follow-up.

Alcoholics Anonymous↗
PubMedDate not supplied

Dementia screening: can a second administration reduce the number of false positives?

OBJECTIVE: Early diagnosis of dementia is important for medical treatment and quality-of-life interventions. The authors examine whether administering a second cognitive screening after a poor initial score can improve the accuracy of diagnosis. Of particular interest is reducing false positives that may generate an unnecessary referral for a dementia work-up. METHODS: A group of 389 Japanese men from the Honolulu-Asia Aging Study were administered the Cognitive Assessment Screening Instrument (CASI) twice within a 2-month period. A small sample received a follow-up CASI 3 years later. RESULTS: Administration of a second CASI reduced the false-positive rate by 16.1% in the total sample and 20.2% in those suspected of having mild dementia. The negative predictive value for the second administration was 80% for the entire sample and 82.6% for those suspected of having mild dementia. CONCLUSION: Administration of a second cognitive screening in patients initially scoring in the dementia range can significantly reduce the number of false positives for dementia. This technique may be useful to managed-care companies who aim to reduce unnecessary costs in medical care.

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