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Biomedical subjects

G W Ross

Publications and source records attributed to G W Ross.

At least 19 recordsLinked to original sources
PubMed2006

Occupational and other risk factors for hand-grip strength: the Honolulu-Asia Aging Study.

BACKGROUND: In certain occupations, including farm work, workers are exposed to hazardous substances, some of which are known to be toxic to the nervous system and may adversely affect muscle strength. Measurement of hand-grip strength may be useful for detecting neurotoxic exposure. METHODS: The authors studied 3522 participants of the Honolulu Heart Program and the Honolulu-Asia Aging Study to determine whether occupational exposures to pesticides, solvents, and metals assessed at exam I (1965-68) are associated with hand-grip strength at exam IV (1991-93) and change in hand-grip strength over 25 years. Correlation, analysis of variance and covariance, and linear regression were used to evaluate the associations. RESULTS: At exam IV, participants ranged in age from 71-93 years; mean hand-grip strength was 39.6 kg at exam I and 30.3 kg at exam IV. Over 25 years, the decline in hand-grip strength was an average of 8-9 kg for all exposures. Hand-grip strength was inversely associated with age and glucose but directly associated with cognitive function, BMI, and haemoglobin level. No other exposures were associated with hand-grip strength. CONCLUSION: This study did not provide evidence that occupational exposure to pesticides, solvents, and metals adversely affected hand-grip strength in this population, but confirmed other important associations with hand-grip strength.

Aged↗
PubMed2006

Neuropathologic findings in essential tremor.

Pathologic findings, including cerebellar changes and brainstem Lewy bodies, distinguished 10 essential tremor (ET) cases from 12 controls. Numbers of torpedoes (p = 0.009) and Bergmann glia (p = 0.046) were increased in cases. Six cases (60%) had Lewy bodies vs 2 controls (16.7%) (odds ratio 7.5, 95% CI 1.04 to 54.1; p = 0.035). Four of these six had an atypical distribution of brainstem Lewy bodies. ET may be pathologically heterogeneous.

Aged, 80 and over↗
PubMed2005

Excessive daytime sleepiness and subsequent development of Parkinson disease.

OBJECTIVE: To determine if excessive daytime sleepiness (EDS) can predate future Parkinson disease (PD). METHODS: EDS was assessed in 3,078 men aged 71 to 93 years in the Honolulu-Asia Aging Study from 1991 to 1993. All were free of prevalent PD and dementia. Follow-up for incident PD was based on three repeat neurologic assessments from 1994 to 2001. RESULTS: During the course of follow-up, 43 men developed PD (19.9/10,000 person-years). After age adjustment, there was more than a threefold excess in the risk of PD in men with EDS vs men without EDS (55.3 vs 17.0/10,000 person-years; odds ratio [OR] = 3.3; 95% CI = 1.4 to 7.0; p = 0.004). Additional adjustment for insomnia, cognitive function, depressed mood, midlife cigarette smoking and coffee drinking, and other factors failed to alter the association between EDS and PD (OR = 2.8; 95% CI = 1.1 to 6.4; p = 0.014). Other sleep related features such as insomnia, daytime napping, early morning grogginess, and frequent nocturnal awakening showed little relation with the risk of PD. CONCLUSIONS: Excessive daytime sleepiness may be associated with an increased risk of developing Parkinson disease.

Aged↗
PubMed2005

Consumption of milk and calcium in midlife and the future risk of Parkinson disease.

OBJECTIVE: To examine the relation between milk and calcium intake in midlife and the risk of Parkinson disease (PD). METHODS: Findings are based on dietary intake observed from 1965 to 1968 in 7,504 men ages 45 to 68 in the Honolulu Heart Program. Men were followed for 30 years for incident PD. RESULTS: In the course of follow-up, 128 developed PD (7.1/10,000 person-years). Age-adjusted incidence of PD increased with milk intake from 6.9/10,000 person-years in men who consumed no milk to 14.9/10,000 person-years in men who consumed >16 oz/day (p = 0.017). After further adjustment for dietary and other factors, there was a 2.3-fold excess of PD (95% CI 1.3 to 4.1) in the highest intake group (>16 oz/day) vs those who consumed no milk. The effect of milk consumption on PD was also independent of the intake of calcium. Calcium from dairy and nondairy sources had no apparent relation with the risk of PD. CONCLUSIONS: Findings suggest that milk intake is associated with an increased risk of Parkinson disease. Whether observed effects are mediated through nutrients other than calcium or through neurotoxic contaminants warrants further study.

Age of Onset↗
PubMed2004

Memory complaints in nondemented men predict future pathologic diagnosis of Alzheimer disease.

The validity of memory complaints as a predictor of Alzheimer disease (AD) was assessed in 237 Japanese-American men autopsied at ages 74 to 97 years. These men were free of dementia at the time memory complaints were assessed 1 to 11 years earlier. Memory complaints were found to predict the neuropathologic diagnosis of AD after adjusting for age, time to death, education, depression, and cognitive functioning.

Aged↗
PubMed2003

Quantification of regional glial fibrillary acidic protein levels in Alzheimer's disease.

OBJECTIVES: Our objectives were to quantify glial fibrillary acidic protein (GFAP) in brains of Alzheimer's disease (AD) cases, and non-AD controls to determine the regions with the most severe gliosis in AD. MATERIAL AND METHODS: In a case control design, we used an enzyme-linked immunosorbent assay (ELISA) to quantify GFAP in frozen brain from four areas of neocortex in 10 AD cases, 10 age-matched controls, and 10 younger controls from the Honolulu-Asia Aging Study autopsy archive. RESULTS: Median age at death was 83.5 years for cases and age-matched controls, and 77 years for younger controls. For the AD cases compared with the age-matched controls, levels of GFAP in occipital (P=0.01), parietal (P=0.028), and temporal lobes (P=0.004) (but not frontal) were significantly higher in the cases. The median GFAP excess in AD cases compared with age matched controls was highest in the temporal lobe. CONCLUSIONS: Regional quantification of GFAP reveals that the glial response is most prominent in the temporal lobe in AD.

Aged↗
PubMed2002

Midlife adiposity and the future risk of Parkinson's disease.

BACKGROUND: Evidence suggests that nigrostriatal system disorders are associated with PD and adiposity. Whether patterns of adiposity coexist or predate clinical PD is unknown. This report examines the relation between midlife adiposity and the risk of PD. METHODS: Measurement of adiposity occurred from 1965 to 1968 in 7,990 men in the Honolulu Heart Program (aged 45 to 68 years and without PD). Adiposity measures included body mass index (BMI), subscapular skinfold thickness (SSF), and triceps skinfold thickness (TSF). Follow-up for incident PD occurred over a 30-year period. RESULTS: During the course of follow-up, PD was observed in 137 men. Among the measures of adiposity, age-adjusted incidence of PD increased threefold from 3.7/10,000 person-years in the bottom quartile of TSF (1 to 5 mm) to 11.1/10,000 person-years in the top quartile (11 to 32 mm, p < 0.001). Effects of TSF on PD were independent of cigarette smoking, coffee consumption, physical activity, daily caloric and fat intake, and the other measures of adiposity (p < 0.001). Whereas rates of PD were lowest in the bottom quartile of BMI and SSF vs higher quartiles, associations with PD were weaker than they were for TSF. The effect of TSF on clinical onset before age 65 years was similar to the effect that was observed in later life. CONCLUSIONS: Increased triceps skinfold thickness measured in midlife is associated with an elevated risk of future PD. Whether patterns of adiposity reflect a unique metabolic pathology in individuals at a high risk of PD warrants further study.

Adipose Tissue↗
PubMed2002

Cerebral amyloid angiopathy and cognitive function: the HAAS autopsy study.

OBJECTIVE: To investigate the relationship between cerebral amyloid angiopathy (CAA), dementia, and cognitive function in an autopsy sample of 211 Japanese-American men from the population-based Honolulu-Asia Aging Study. METHODS: Starting in 1991, participants were assessed with the Cognitive Abilities Screening Instrument (CASI) and diagnosed with dementia (including subtype) based on published criteria. At autopsy, neuropathologists blinded to clinical data examined brains for neurofibrillary tangles (NFT), neuritic plaques (NP), and a number of vascular pathologies, including CAA. CAA was detected by immunostaining for betaA4 amyloid in parenchymal vessels in the neocortex and semiquantitatively rated. Linear regression models were used to examine the association of CASI score, dementia subtype, and CAA controlling for age at death, time between CASI administration and death, education, NP and NFT counts, infarcts, hemorrhage, and APOE genotype. RESULTS: A total of 44.1% of subjects had CAA in at least one neocortical area. The presence of CAA was associated with higher mean NFT and NP counts and having at least one APOE-epsilon4 allele. The interaction between CAA and AD on the adjusted mean CASI score was significant; compared with nondemented men without CAA, the CASI score was 16.6% lower in men with AD and no CAA and 45.9% lower in men with AD plus CAA. CONCLUSIONS: CAA may contribute to the clinical presentation of dementia by interacting with other neuronal pathologies, leading to more severe cognitive impairment in men with both CAA and AD compared with men with only AD or CAA.

Aged↗
PubMed2001

Joint effect of the APOE gene and midlife systolic blood pressure on late-life cognitive impairment: the Honolulu-Asia aging study.

BACKGROUND AND PURPOSE: The aim of this study was to explore the joint effect of the APOE epsilon4 allele and midlife systolic blood pressure (SBP) on the risk for poor cognitive function in late life. METHODS: The study includes 3605 surviving members of the cohort of the Japanese-American men followed prospectively over 26 years (1965-1991) as a part of the Honolulu Heart Program. In 1965 men were aged 45 to 68 years and were living in the island of Oahu, Hawaii. For this study the sample was divided into 4 categories: normal SBP (<160 mm Hg)/No epsilon4, as the reference category; normal SBP/epsilon4; high SBP/no epsilon4; high SBP/epsilon4. The relative risk (RR) of late-life intermediate and poor cognitive function relative to good function was measured by the Cognitive Abilities Screening Instrument (CASI) test. RESULTS: After adjusting for age, education, smoking, alcohol use, and body mass index, the RR for poor cognitive function (CASI <74) compared with good cognitive function (CASI >/=82) in never-treated subjects was 1.3 (95% CI 0.9 to 1.9) for the normal SBP/epsilon4 category, 2.6 (0.7 to 10.0) for the high SBP/no epsilon4, and 13.0 (1.9 to 83.8) for the high SBP/epsilon4. Adjustment for diabetes, prevalent stroke, coronary disease, and ankle-brachial index reduced the RR of poor cognition by 25.5% (RR 13.0 to 10.8) in those with both risk factors. In the treated group, the RR was 1.9 (0.7 to 4.5) for those with both risk factors. CONCLUSIONS: The results suggest that midlife high SBP has a stronger adverse effect on cognitive function in persons with higher genetic susceptibility, but this effect may be modified by antihypertensive treatment.

Aged↗
PubMed2001

Cholesterol and neuropathologic markers of AD: a population-based autopsy study.

OBJECTIVE: To examine the association of plasma cholesterol (total and high-density [HDL] and low-density lipoprotein) levels with neuritic plaques (NP) and neurofibrillary tangles (NFT) in a population-based autopsy series of 218 Japanese American men followed as a part of the Honolulu-Asia Aging Study. METHODS: Cholesterol levels were measured in late life (average age at death 84.6 years) in all subjects (n = 218) and in midlife (20 years before late life) in a subsample (n = 89); for the analyses, levels were categorized into quintiles, with the lowest quintile serving as the reference. Tissue from four areas of neocortex and two areas of hippocampus was prepared with Bielschowsky silver-stained sections and evaluated by one of three neuropathologists who were blinded to clinical information. Diffuse and neuritic plaques and NFT were counted in field areas standardized to 1 mm(2). Fields were selected from areas with the highest numbers of lesions, and the field with the highest count was taken to represent the brain area. RESULTS: After adjusting for age at death, education, APOE allele, dementia, neuropathologic infarction, and blood pressure, a strong linear association was found for increasing late-life HDL cholesterol (HDL-C) levels and an increasing number of neocortical NP (5th versus 1st quintile: count ratio [95% CI] 2.30 [1.05 to 5.06]) and hippocampal (2.63 [1.25 to 5.50]) and neocortical (4.20 [1.73 to 10.16]) NFT. Trends were similar for the midlife HDL-C levels. CONCLUSIONS: The constituents of HDL-C may play a role in the formation of AD pathology, and these processes are reflected in peripheral measures.

Aged↗
PubMed2001

Frequency of bowel movements and the future risk of Parkinson's disease.

BACKGROUND: Constipation is frequent in PD, although its onset in relation to clinical PD has not been well described. Demonstration that constipation can precede clinical PD could provide important clues to understanding disease progression and etiology. The purpose of this report is to examine the association between the frequency of bowel movements and the future risk of PD. METHODS: Information on the frequency of bowel movements was collected from 1971 to 1974 in 6790 men aged 51 to 75 years without PD in the Honolulu Heart Program. Follow-up for incident PD occurred over a 24-year period. RESULTS: Ninety-six men developed PD an average of 12 years into follow-up. Age-adjusted incidence declined consistently from 18.9/10,000 person-years in men with <1 bowel movement/day to 3.8/10,000 person-years in those with >2/day (p = 0.005). After adjustment for age, pack-years of cigarette smoking, coffee consumption, laxative use, jogging, and the intake of fruits, vegetables, and grains, men with <1 bowel movement/day had a 2.7-fold excess risk of PD versus men with 1/day (95% CI: 1.3, 5.5; p = 0.007). The risk of PD in men with <1 bowel movement/day increased to a 4.1-fold excess when compared with men with 2/day (95% CI: 1.7, 9.6; p = 0.001) and to a 4.5-fold excess versus men with >2/day (95% CI: 1.2, 16.9; p = 0.025). CONCLUSIONS: Findings indicate that infrequent bowel movements are associated with an elevated risk of future PD. Further study is needed to determine whether constipation is part of early PD processes or is a marker of susceptibility or environmental factors that may cause PD.

Age Factors↗
PubMed2001

Accuracy of clinical criteria for AD in the Honolulu-Asia Aging Study, a population-based study.

OBJECTIVE: To determine diagnostic accuracy for AD in a population-based study of Japanese-American men. AD is neuropathologically confirmed for more than 80% of cases at major referral centers (primarily Caucasians); however, information on diagnostic accuracy in population-based studies and studies of different ethnic groups is limited. METHODS: There were 3,734 men who participated in the Honolulu-Asia Aging Study 1991 through 1993 dementia examination and 2,603 in the 1994 through 1996 examination. Diagnoses were based on published criteria. Neuropathologists blinded to clinical data quantified neurofibrillary tangles (NFT) and neuritic plaques (NP). RESULTS: Of 220 autopsied subjects, clinical evaluation revealed 68 with normal cognition, 73 intermediate, and 79 with dementia: 20 AD, 27 vascular dementia, 19 AD + other, and 13 other dementia. Among 20 cases with pure AD, the median value for maximum neocortical NFT density was 6.9/mm(2) and for neocortical NP density was 8.0/mm2. Corresponding densities for other groups were <3.0/mm2. Using established neuropathologic criteria, 25% (5/20) of clinical AD cases had enough NP to meet definite AD criteria, whereas 65% (13/20) had sufficient NP to meet neuropathologic definite or probable AD criteria. Among nine AD cases with moderately severe dementia, only two (22%) had NP densities great enough to meet definite neuropathologic criteria, whereas seven (78%) met neuropathologic criteria for probable AD. CONCLUSIONS: Neuropathologic confirmation and NP density among decedents with clinical AD in this population-based study were lower than reported by referral centers and similar to reports from two other community studies. Ethnic differences in propensity for amyloid deposition as well as differences in clinical severity and representativeness of cases might contribute to these findings.

Aged↗
PubMed2001

Ankle-brachial blood pressure in elderly men and the risk of stroke: the Honolulu Heart Program.

Although low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, it has not been identified as a risk factor for stroke. The purpose of this report is to examine the relation between ABI and stroke in elderly men. ABI was measured from 1991 to 1993 in 2767 men aged 71 to 93 years in the Honolulu Heart Program without a history of stroke and coronary heart disease. Subjects were followed for 3 to 6 years for fatal and nonfatal thromboembolic and hemorrhagic stroke. During follow-up, there were 91 strokes. There was an age-adjusted 2-fold excess in men with an ABI < 0.9 (6.0%) versus men with an ABI > or = 0.9 (2.9%, P < 0.01). Thromboembolic events occurred in 4.6% of men with an ABI < 0.9 and in 2.0% in those with an ABI > or = 0.9 (P < 0.01). Hemorrhagic stroke was also more frequent in men with a low ABI (< 0.9) versus a higher ABI (1.9 vs. 0.8%, respectively). After adjusting for other factors, the risk of total and thromboembolic strokes increased with declining ABI (P = 0.019 and P = 0.004, respectively). The relation between ABI and stroke was similar and statistically significant in the presence and absence of diabetes and hypertension (P < 0.05). Findings suggest that ABI is inversely related to the incidence of stroke. Simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of stroke in the elderly.

Age Distribution↗
PubMed2001

Resident interpretation of emergency CT scans in the evaluation of acute appendicitis.

PURPOSE: Radiology resident interpretation of computed tomographic (CT) scans at academic institutions often guides management of cases of suspected acute appendicitis in the emergency department. The purpose of this study was to compare resident and faculty interpretation of CT scans obtained for acute appendicitis. MATERIALS AND METHODS: From December 16, 1999, to July 13, 2000, CT was performed in 103 consecutive patients between the hours of 9:00 PM and 8:00 AM who were suspected of having acute appendicitis. The authors compared the residents' preliminary written interpretations with both the final reports written by the faculty and the surgical findings. The faculty interpreting the CT scans were aware of resident interpretations but were not aware that a study was being conducted. RESULTS: The final faculty interpretation and the preliminary resident interpretation were identical in 96 of the 103 patients (93%; 95% confidence interval: 87.8%, 97.2%). In only one patient was a scan originally interpreted as negative interpreted as positive by the faculty member. Clinically, the patient did not have acute appendicitis, and surgery was not perforrmed. CONCLUSION: In the diagnosis of acute appendicitis, image interpretations made by adequately trained radiology residents can be expected to closely match those of the radiology faculty, and the practice of after-hours interpretation of such studies by radiology residents is safe.

Acute Disease↗
PubMed2001

beta(2)-Glycoprotein 1-dependent anticardiolipin antibodies and risk of ischemic stroke and myocardial infarction: the honolulu heart program.

BACKGROUND: It has been hypothesized that immunoreactivity to beta(2)-glycoprotein 1 (beta2GP1)-dependent anticardiolipin antibody (aCL), but not beta2GP1-independent aCL, is associated with increased risk of ischemic stroke and myocardial infarction (MI). METHODS: We performed a nested case-control study examining aCL as a risk factor for ischemic stroke and MI by using stored frozen sera obtained from subjects enrolled in the Honolulu Heart Program and followed for up for 20 years. We measured beta2GP1-dependent and beta2GP1-independent aCL and anti-beta2GP1 immunoreactivity in 259 men who developed an ischemic stroke, in 374 men who developed an MI, and in a control group of 1360 men who remained free of both conditions. RESULTS: Only beta2GP1-dependent aCL of the IgG class was significantly associated with both incident ischemic stroke and MI. This association was attenuated in the last 5 years of the 20-year follow-up. For stroke, the risk factor-adjusted relative odds for men with a positive versus a negative beta2GP1-dependent aCL of the IgG class were 2.2 (95% CI 1.5 to 3.4) at 15 years and 1.5 (95% CI 1.0 to 2.3) at 20 years. For MI, the adjusted relative odds were 1.8 (95% CI 1.2 to 2.6) at 15 years and 1.5 (95% CI 1.1 to 2.1) at 20 years. CONCLUSIONS: These data suggest that aCL IgG, particularly the beta2GP1-dependent variety, is an important predictor of future stroke and MI in men.

Age Distribution↗
PubMed2001

Current evidence for neuroprotective effects of nicotine and caffeine against Parkinson's disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder affecting 1 to 3% of individuals over the age of 65 years. While effective therapy exists for treating the bradykinesia, rigidity and tremor associated with the disease, the cause is unknown. There is no treatment available to prevent or slow the progressive neuronal loss in the substantia nigra and associated decreased levels of dopamine in the striatum that underlie the cardinal features of the disease. Both retrospective and prospective epidemiological studies have consistently demonstrated an inverse association between cigarette smoking and PD, leading to theories that smoking in general and nicotine in particular might be neuroprotective. Nicotine has been shown in animals to stimulate the release of dopamine in the striatum, and to preserve nigral neurons and striatal dopamine levels in laboratory animals with lesioned nigrostriatal pathways. Coffee and caffeine consumption have also been shown in epidemiological studies to be inversely related to PD risk. Caffeine is an adenosine A(2A) receptor antagonist that enhances locomotor activity in animal models of parkinsonism. Theophylline, a related compound that has A(2A) receptor blocking properties, has been shown in one small trial to improve motor function in patients with PD. Recently, potent and highly selective A(2A) receptor antagonists have been developed that have demonstrated improvement in motor function in animal models of parkinsonism. Exciting findings are emerging that demonstrate attenuation of dopaminergic neurotoxicity with caffeine and other adenosine receptor antagonists in mice given the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), suggesting that these compounds may be neuroprotective. Evidence for the neuroprotective potential of nicotine and caffeine is compelling, but further work is needed before testing these and related compounds in clinical trials for both individuals at high risk of developing PD and those with early, untreated disease.

Caffeine↗
PubMed2000

Ankle/brachial blood pressure in men >70 years of age and the risk of coronary heart disease.

Low ankle/brachial blood pressure index (ABI) is a marker of generalized atherosclerosis in the elderly, although its association with coronary heart disease (CHD) has not been well established. The purpose of this report is to examine the relation between ABI and the risk of CHD in a sample of elderly men. Findings are based on the ABI that was measured in 2,863 Japanese-American men aged 71 to 93 years at an examination that occurred from 1991 to 1993 in the Honolulu Heart Program. All men were free of total CHD at that time and followed for nonfatal myocardial infarction and death from CHD over a 3- to 6-year period. During follow-up, 186 had a coronary event. Age-adjusted incidence declined significantly from 15.3% in men with an ABI <0.8 to 5.4% in men with an ABI >/=1.0 (p <0.001). The effect of ABI on disease was similar across a variety of risk factor strata, although it seemed strongest in the presence of hypertension and in past and current cigarette smokers. Adjustment for other risk factors failed to diminish the relation between ABI and CHD. We conclude that a low ABI increases the risk of CHD in elderly men. If findings can be extended to other elderly population segments, simple measurement of ABI in an outpatient setting could be an important tool for assessing the risk of CHD in the elderly.

Aged↗