Search PubMed⌕ Search

Biomedical subjects

G W Ross

Publications and source records attributed to G W Ross.

At least 37 records · Page 2Linked to original sources
PubMed2000

APOE-epsilon4 predicts incident AD in Japanese-American men: the honolulu-asia aging study.

The authors assessed the 3-year incidence of dementia, including subtypes, in 2,603 Japanese-American men 71 to 93 years of age who were dementia free at baseline. There were 137 new cases of dementia according to the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised, including 51 with a primary diagnosis of AD. The rates for all subtypes increased with age. Men with an APOE4 allele had a significantly increased risk of AD of 2.39 (95% CI, 1.07, 5.31), after adjusting for age and education. There was no significant relationship of APOE4 with other subtypes of dementia.

Age Distribution↗
PubMed2000

Association of vitamin E and C supplement use with cognitive function and dementia in elderly men.

OBJECTIVE: To determine whether use of vitamin E and C supplements protects against subsequent development of dementia and poor cognitive functioning. METHODS: The Honolulu-Asia Aging Study is a longitudinal study of Japanese-American men living in Hawaii. Data for this study were obtained from a subsample of the cohort interviewed in 1982, and from the entire cohort from a mailed questionnaire in 1988 and the dementia prevalence survey in 1991 to 1993. The subjects included 3,385 men, age 71 to 93 years, whose use of vitamin E and C supplements had been ascertained previously. Cognitive performance was assessed with the Cognitive Abilities Screening Instrument, and subjects were stratified into four groups: low, low normal, mid normal, and high normal. For the dementia analyses, subjects were divided into five mutually exclusive groups: AD (n = 47), vascular dementia (n = 35), mixed/other types of dementia (n = 50), low cognitive test scorers without diagnosed dementia (n = 254), and cognitively intact (n = 2,999; reference). RESULTS: In a multivariate model controlling for other factors, a significant protective effect was found for vascular dementia in men who had reported taking both vitamin E and C supplements in 1988 (odds ratio [OR], 0.12; 95% CI, 0.02 to 0.88). They were also protected against mixed/other dementia (OR, 0.31; 95% CI, 0.11 to 0.89). No protective effect was found for Alzheimer's dementia (OR, 1.81; 95% CI, 0.91 to 3.62). Among those without dementia, use of either vitamin E or C supplements alone in 1988 was associated significantly with better cognitive test performance at the 1991 to 1993 examination (OR, 1.25; 95% CI, 1.04 to 1.50), and use of both vitamin E and C together had borderline significance (OR, 1.18; 95% CI, 0.995 to 1.39). CONCLUSIONS: These results suggest that vitamin E and C supplements may protect against vascular dementia and may improve cognitive function in late life.

Aged↗
PubMed2000

Brain aging and midlife tofu consumption.

OBJECTIVE: To examine associations of midlife tofu consumption with brain function and structural changes in late life. METHODS: The design utilized surviving participants of a longitudinal study established in 1965 for research on heart disease, stroke, and cancer. Information on consumption of selected foods was available from standardized interviews conducted 1965-1967 and 1971-1974. A 4-level composite intake index defined "low-low" consumption as fewer than two servings of tofu per week in 1965 and no tofu in the prior week in 1971. Men who reported two or more servings per week at both interviews were defined as "high-high" consumers. Intermediate or less consistent "low" and "high" consumption levels were also defined. Cognitive functioning was tested at the 1991-1993 examination, when participants were aged 71 to 93 years (n = 3734). Brain atrophy was assessed using neuroimage (n = 574) and autopsy (n = 290) information. Cognitive function data were also analyzed for wives of a sample of study participants (n = 502) who had been living with the participants at the time of their dietary interviews. RESULTS: Poor cognitive test performance, enlargement of ventricles and low brain weight were each significantly and independently associated with higher midlife tofu consumption. A similar association of midlife tofu intake with poor late life cognitive test scores was also observed among wives of cohort members, using the husband's answers to food frequency questions as proxy for the wife's consumption. Statistically significant associations were consistently demonstrated in linear and logistic multivariate regression models. Odds ratios comparing endpoints among "high-high" with "low-low" consumers were mostly in the range of 1.6 to 2.0. CONCLUSIONS: In this population, higher midlife tofu consumption was independently associated with indicators of cognitive impairment and brain atrophy in late life.

Aged↗
PubMed2000

The effects of childhood residence in Japan and testing language on cognitive performance in late life among Japanese American men in Hawaii.

OBJECTIVES: To examine the association of years spent in Japan during childhood with cognitive test performance in late life among Japanese American men, and to assess the influence of the language used for testing on this association. DESIGN: A cross-sectional study. SETTING/PARTICIPANTS: A total of 3734 Japanese American men, aged 71-93 years, who were first- or second-generation migrants and living on Oahu Island, Hawaii. MEASUREMENTS: The outcome variable was cognitive test performance assessed using the Cognitive Abilities Screening Instrument (CASI), which was developed for cross-cultural studies of cognitive impairment. The explanatory variable of main interest was the number of years spent in Japan during school-age childhood years (ages 6-17). The associations of CASI scores with childhood years in Japan was evaluated using a stepwise multiple linear regression model in which a total of 40 potential confounders were included as covariates. RESULTS: In the total sample, there was an inverse association between CASI scores and middle childhood years in Japan. This association remained significant after controlling for age, education, socioeconomic status, traditional Japanese food consumption, pulmonary function, apolipoprotein E4, proficiency in speaking Japanese, and other possible confounders. When data were analyzed separately for subgroups according to the language preferred at testing (English or Japanese), associations between childhood years in Japan and CASI scores were in opposite directions negative for the group tested in English and positive for the group tested in Japanese. The interaction between the testing language and childhood years in Japan was statistically significant. CONCLUSIONS: There was an inverse association between years spent in Japan during school-age years of childhood and cognitive test performance in late life. This association could not be accounted for by age, education, or other confounding factors. However, this finding was not observed in participants who preferred being tested in Japanese. To assess cognitive test performance in older people, it is of prime importance to use the most optimal language for testing, usually the subject's native language.

Adolescent↗
PubMed2000

Driving cessation in older men with incident dementia.

OBJECTIVE: To determine the prevalence and cessation of driving among older men with incident dementia in the Honolulu-Asia Aging Study. DESIGN: Retrospective cohort data from a community-based study of incident dementia. SETTING: The Honolulu Heart Program and the Honolulu-Asia Aging Study. PARTICIPANTS: A total of 643 men who were evaluated for the incidence of Alzheimer's disease or other dementia between the fourth and the fifth examination of the Honolulu Heart Program. MEASUREMENTS: Driving history, diagnosis of dementia, grip strength, walking speed, standing balance test, interviewer's rating of vision status, and the neurologist's notes on mentions of driving behavior from informal interviews with a caregiver or family informant. RESULTS: The prevalence of driving declined dramatically with level of cognitive functioning. Among 162 men evaluated and found to have normal cognitive functioning, 78% still drove, compared with 62% of 287 men with poor cognitive functioning but no clinical dementia, 46% of 96 men with a new diagnosis of very mild dementia (Clinical Dementia Rating = 0.5), and 22% of 98 men with a new diagnosis of mild dementia (CDR = 1). Only one of 23 men diagnosed with moderate or more severe staged incident dementia (CDR > 1) was driving. About 10% of the 59 demented persons still driving relied on co-pilots, and only one driver was reported as involved in a crash according to a review of the neurologists' notes. CONCLUSIONS: Incident dementia is a major cause of driving cessation. Based on these data, we estimate that approximately 4% of male drivers aged 75 years and older nationwide (about 175,000 men) have dementia. This number will increase with the projected growth of drivers aged 75 years and older.

Activities of Daily Living↗
PubMed2000

Metabolic cardiovascular syndrome and risk of dementia in Japanese-American elderly men. The Honolulu-Asia aging study.

Cardiovascular risk factors often cluster into a metabolic syndrome that may increase the risk of dementia. The objective of the present study was to assess the long-term association between clustered metabolic cardiovascular risk factors measured at middle age and the risk of dementia in old age. This prospective cohort study of cardiovascular disease was started in 1965 and was extended to a study of dementia in 1991. The subjects were Japanese-American men with an average age of 52.7+/-4.7 (mean+/-SD) years at baseline. Dementia was diagnosed in 215 men, according to international criteria, and was based on a clinical examination, neuropsychological testing, and an informant interview. The z scores were calculated for 7 risk factors (random postload glucose, diastolic and systolic blood pressures, body mass index, subscapular skinfold thickness, random triglycerides, and total cholesterol). The relative risk (RR [95% CI]) of dementia (subtypes) per 1 SD increase in the sum of the z scores was assessed after adjustment for age, education, occupation, alcohol consumption, cigarette smoking, and years of childhood lived in Japan. The z-score sum was higher in demented subjects than in nondemented subjects, indicating a higher risk factor burden (0.74 versus -0.06, respectively; P=0. 008). Per SD increase in the z-score sum, the risk of dementia was increased by 5% (RR 1.05, 95% CI 1.02 to 1.09). The z-score sum was specifically associated with vascular dementia (RR 1.11, 95% CI 1.05 to 1.18) but not with Alzheimer's disease (RR 1.00, 95% CI 0.94 to 1.05). Clustering of metabolic cardiovascular risk factors increases the risk of dementia (mainly, dementia of vascular origin).

Age Factors↗
PubMed2000

A longitudinal study of drinking and cognitive performance in elderly Japanese American men: the Honolulu-Asia Aging Study.

OBJECTIVES: This study prospectively describes the relationships between alcohol intake and subsequent cognitive performance among participants in the Honolulu Heart Program (HHP). METHODS: Alcohol intake was assessed at Exam III of the HHP, and cognitive performance was measured approximately 18 years later with the Cognitive Abilities Screening Instrument (CASI). Complete information was available for 3556 participants, aged 71 to 93 years at follow-up. RESULTS: In multivariate analyses, the relationship between drinking and later cognitive performance appeared nonlinear, as nondrinkers and heavy drinkers (more than 60 ounces of alcohol per month) had the lowest CASI scores and the highest risks of poor and intermediate CASI outcomes. Compared with nondrinkers, the risk of a poor CASI score was lowered by 22% to 40% among men who consumed 1-60 ounces of alcohol per month. CONCLUSIONS: We report a positive association between moderate alcohol intake among middle-aged men and subsequent cognitive performance in later life. However, it is possible that the health risks associated with drinking outweight any potential benefits for many elderly persons.

Aged↗
PubMed1999

Characterization of risk factors for vascular dementia: the Honolulu-Asia Aging Study.

BACKGROUND: The Honolulu Heart Program (HHP) is a prospective study of heart disease and stroke that has accumulated risk factor data on a cohort of 8,006 Japanese American men since the study began in 1965. A recent examination of the cohort identified all patients with vascular dementia (VaD) using the criteria of the California Alzheimer's Disease Diagnostic and Treatment Center. OBJECTIVE: To characterize patients with VaD by stroke subtype and to investigate risk factors for VaD in a cohort of Japanese American men, aged 71 to 93, living in Hawaii and participating in the HHP. METHODS: Sixty-eight men with VaD were compared with 3,335 men without dementia or stroke (NSND). Men with VaD were also compared with 106 men with stroke who were not demented (SND). Candidate risk factors were measured prospectively. RESULTS: Of the 68 men with VaD there were 34 (50%) whose VaD was attributed to small vessel infarcts, 16 (23%) whose VaD was related to large vessel infarcts, and 11 (16%) with both large and small vessel infarcts. The remainder could not be classified. In a multivariate logistic regression model for VaD compared with NSND containing variables found to be associated with VaD in a univariate analysis, age (odds ratio [OR] 1.19, 95% confidence interval [CI] 1.13 to 1.27), coronary heart disease (OR 2.50, 95% CI 1.35 to 4.62), and 1-hour postprandial glucose (OR 1.41, 95% CI 1.06 to 1.88) remained significantly predictive of VaD, whereas preference for a Western diet (OR 0.54, 95% CI 0.30 to 0.98) as opposed to an Oriental or mixed diet and use of supplementary vitamin E (OR 0.32, 95% CI 0.12 to 0.82) were protective. A similar model for the comparison of men with VaD and SND revealed age (OR 1.24, 95% CI 1.14 to 1.35) was predictive of VaD, whereas preference for a Western diet (OR 0.43, 95% CI 0.22 to 0.86) was protective. CONCLUSIONS: The most common stroke subtype associated with VaD was lacunar stroke. Age and traditional vascular risk factors are important contributors to the development of VaD in late life. The antioxidant vitamin E and presently unknown factors related to a Western diet as opposed to an Oriental diet may be protective against developing VaD.

Aged↗
PubMed1999

Effects of walking on coronary heart disease in elderly men: the Honolulu Heart Program.

BACKGROUND: Effects of walking on the risk of coronary heart disease morbidity and mortality have not been identified in the elderly. The purpose of this study was to determine whether walking is associated with a reduced risk of coronary heart disease in a sample of elderly men. METHODS AND RESULTS: For this study, distance walked (mile/d) was examined at a baseline examination that occurred from 1991 to 1993 in the Honolulu Heart Program. Incident coronary heart disease from all causes was observed over a 2- to 4-year follow-up period. Subjects followed up were 2678 physically capable elderly men aged 71 to 93 years. During the course of follow-up, 109 men developed coronary heart disease. Men who walked <0.25 mile/d had a 2-fold increased risk of coronary heart disease versus those who walked >1. 5 mile/d (5.1% versus 2.5%; P<0.01). Men who walked 0.25 to 1.5 mile/d were also at a significantly higher risk of coronary heart disease than men who walked longer distances (4.5% versus 2.5%; P<0. 05). Adjustment for age and other risk factors failed to alter these findings. CONCLUSIONS: Findings from the Honolulu Heart Program, which targeted physically capable elderly men, suggest that the risk of coronary heart disease is reduced with increases in distance walked. Combined with evidence that suggests that an active lifestyle reduces the risk of cardiovascular disease in younger and more diverse groups, this suggests that important health benefits could be derived by encouraging the elderly to walk.

Aged↗
PubMed1999

Longitudinal association of vascular and Alzheimer's dementias, diabetes, and glucose tolerance.

OBJECTIVE: To assess the relationship between impaired glucose tolerance and both vascular dementia and AD. BACKGROUND: Diabetes and abnormalities of glucose metabolism have been associated with stroke and poor cognitive function. In addition, glycoproteins and glycosylation have been postulated to be associated with the development of neuritic plaques characteristic of AD. METHODS: A historical prospective cohort study of Japanese-American men (n = 3,774), who were examined at ages 45 to 68 (1965 through 1968) and again at ages 71 to 93 (1991 through 1993). Measurements were obtained by clinical and home examinations: assessment of glucose intolerance (nonfasting 1 hour after glucose load) from 1965 through 1968 and history of diabetes diagnosed by a physician at examinations given from 1965 through 1968 and from 1976 through 1978. At the 1991 through 1993 examinations, the Cognitive Assessment Screening Instrument (CASI)-an instrument designed for use in cross-cultural settings combining features of the Folstein Mini-Mental State Examination, the Modified Mini-Mental State Examination, and the Hasegawa Dementia Screening Scale-was used. Diagnosis and classification of AD and vascular dementia were made by a consensus panel using neuropsychologic assessment data, a neurologist's evaluation, and information from a family informant. Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., revised criteria were used to establish dementia, and subclassification by cause was based on other published criteria. RESULTS: No association between AD and diabetes, present either 25 or 15 years previously, was found after adjustment for age and education in a multiple regression model. A significant association was found between impaired glucose tolerance at baseline and vascular dementia (p < 0.01). CONCLUSIONS: These findings confirm expected relationships between impaired glucose tolerance and stroke-related dementia but do not support an association of disordered glucose metabolism with AD.

Aged↗
PubMed1998

Influence of myocardial infarction, coronary artery bypass surgery, and stroke on cognitive impairment in late life.

Relations between cognitive test scores in later life and prior myocardial infarction (MI), coronary artery bypass graft surgery (CABG), and stroke were examined for this study. Subjects were 3,734 Japanese-American men (80% of surviving Honolulu Heart Program cohort) aged 71 to 93 years at the time of cognitive testing. Impairment was defined as scoring below the 16th percentile on a validated cognitive assessment scale. Prior MI, stroke, and CABG were established using hospital surveillance, history, and record review. After adjustment for age, years of education, and years of childhood spent in Japan, men with prior stroke were significantly more likely than others to have poor cognitive performance (odds ratio 4.4, 95% confidence limits 3.0 to 6.7). History of > 1 stroke was associated with an odds ratio of 50 (95% confidence limits 10.5 to 238.3). There was no significant association between cognitive performance and > or = 1 prior MI or history of CABG. Time between events and cognitive function testing did not affect results. Analyses support a significant association between clinical stroke and persistent cognitive impairment, but fail to implicate CABG or MI.

Aged↗
PubMed1998

Effects of walking on mortality among nonsmoking retired men.

BACKGROUND: The potential benefit of low-intensity activity in terms of longevity among older men has not been clearly documented. We examined the association between walking and mortality in a cohort of retired men who were nonsmokers and physically capable of participating in low-intensity activities on a daily basis. METHODS: We studied 707 nonsmoking retired men, 61 to 81 years of age, who were enrolled in the Honolulu Heart Program. The distance walked (miles per day) was recorded at a base-line examination, which took place between 1980 and 1982. Data on overall mortality (from any cause) were collected over a 12-year period of follow-up. RESULTS: During the follow-up period, there were 208 deaths. After adjustment for age, the mortality rate among the men who walked less than 1 mile (1.6 km) per day was nearly twice that among those who walked more than 2 miles (3.2 km) per day (40.5 percent vs. 23.8 percent, P=0.001). The cumulative incidence of death after 12 years for the most active walkers was reached in less than 7 years among the men who were least active. The distance walked remained inversely related to mortality after adjustment for overall measures of activity and other risk factors (P=0.01). CONCLUSIONS: Our findings in older physically capable men indicate that regular walking is associated with a lower overall mortality rate. Encouraging elderly people to walk may benefit their health.

Aged↗
PubMed1998

Coffee consumption in hypertensive men in older middle-age and the risk of stroke: the Honolulu Heart Program.

OBJECTIVE: To examine the association between coffee consumption and the development of stroke in men at high risk for cardiovascular disease. METHODS: Coffee intake was observed from 1965 to 1968 in a cohort of men enrolled in the Honolulu Heart Program with follow-up for incident stroke over a 25-year period. Subjects were 499 hypertensive men (having systolic or diastolic blood pressures at or above 140 and 90 mm Hg, respectively) in older middle-age (55 to 68 years) when follow-up began. Past and current cigarette smokers were excluded from follow-up. RESULTS: In the course of follow-up, 76 men developed a stroke. After age-adjustment, risk of thromboembolic stroke increased significantly with increases in coffee consumption (P = 0.002). No relationships were observed with hemorrhagic stroke. When adjusted for other factors, the risk of thromboembolic stroke was more than doubled for men who consumed three cups of coffee per day as compared to nondrinkers of coffee (RR = 2.1; 95% CI = 1.2-3.7). CONCLUSIONS: Although in need of further confirmation, consumption of coffee appears to be positively associated with an increased risk of thromboembolic stroke in hypertensive men in older middle-age. Findings suggest that it may be prudent to advise older middle-aged men with hypertension who consume large amounts of coffee to consider reducing their coffee intake.

Aged↗
PubMed1998

Height as a marker of childhood development and late-life cognitive function: the Honolulu-Asia Aging Study.

OBJECTIVE: Growing evidence suggests that structural and functional brain reserves, thought to develop in childhood and adolescence, may be crucial in determining when cognitive impairment begins. The purpose of this report is to examine the relationship of height, as a marker of childhood development, to late-life cognitive function in a sample of elderly Japanese-American men. METHOD: Cognitive performance was assessed from 1991 to 1993 in the Honolulu-Asia Aging Study in 3733 men aged 71 to 93 years and related to height that was measured 25 years earlier. RESULTS: Among the study sample, shorter men were older, leaner, and less educated than taller men. Shorter men also spent more years of their childhood living in Japan and were more likely to have had fathers in unskilled professions. After adjustment for age, the prevalence of poor cognitive performance declined consistently with increasing height from 25% in men shorter than 154 cm (61 in) to 9% in those taller than 174 cm (69 in). Excluding men with stroke or dementia did not alter the association between height and cognitive performance. Apolipoprotein E4 was unrelated to height and did not effect the association between height and cognitive function. The prevalence of Alzheimer's disease was higher in men who were 154 cm (61 in) or shorter as compared with men who were taller (4.7% vs 2.9%, respectively). There was no association between height and vascular dementia. CONCLUSION: Efforts to improve prenatal and early life conditions to maximize growth in childhood and adolescence could diminish or delay the expression of cognitive impairments that occur later in life. Prevention of some late-life cognitive impairments may have pediatric origins.

Aged↗
PubMed1997

Frequency and characteristics of silent dementia among elderly Japanese-American men. The Honolulu-Asia Aging Study.

OBJECTIVE: To determine the frequency of unrecognized dementia in a group of men found to have dementia by population survey, and to identify factors associated with the failure of a family informant to recognize significant memory impairment. DESIGN AND SETTING: The Honolulu-Asia Aging Study, a population-based study of dementia among elderly Japanese-American men living on the island of Oahu, Hawaii. Data for this study were from the dementia prevalence survey, 1991-1993. STUDY PARTICIPANTS: A total of 191 noninstitutionalized men with dementia who had a reliable family informant. MAIN OUTCOME MEASURES: Failure of family informants to recognize a problem with thinking or memory in subjects with dementia. RESULTS: A total of 21% of family informants failed to recognize a problem with memory among subjects subsequently found to have dementia. Among subjects with very mild dementia, 52% of family informants failed to recognize a significant memory problem compared with 13% among more severely demented subjects. Of the subjects with dementia whose family informants did recognize a memory problem, 53% failed to receive a medical evaluation for this problem. For all family informants, increasing age, fewer years of education, less severe dementia, fewer behavioral complications, fewer functional disabilities, and better performance on certain tests of memory and language were significantly associated with the family informant's failure to recognize a problem with memory. When the family informants were wives living with husbands, less severe dementia, fewer behavioral complications, fewer functional disabilities, and intact remote memory were associated with unrecognized dementia. CONCLUSIONS: Unrecognized dementia was common in our population, especially among mild cases. Cognitive screening programs for the elderly and public education policies designed to increase awareness of early signs of dementia are needed if interventions for individuals with potentially treatable dementias are to be implemented.

Aged↗
PubMed1996

Prevalence of dementia in older Japanese-American men in Hawaii: The Honolulu-Asia Aging Study.

OBJECTIVE: To determine prevalence of dementia and its subtypes in Japanese-American men and compare these findings with rates reported for populations in Japan and elsewhere. DESIGN AND SETTING: The Honolulu Heart Program is a prospective population-based study of cardiovascular disease established in 1965. Prevalence estimates were computed from cases identified at the 1991 to 1993 examination. Cognitive performance was assessed using standardized methods, instruments, and diagnostic criteria. PARTICIPANTS: Subjects were 3734 Japanese-American men (80% of surviving cohort) aged 71 through 93 years, living in the community or in institutions. MAIN OUTCOME MEASURES: Age-specific, age-standardized, and cohort prevalence estimates were computed for dementia (all cause) defined by 2 sets of diagnostic criteria and 4 levels of severity. Prevalence levels for Alzheimer disease and vascular dementia were also estimated. RESULTS: Dementia prevalence by Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised ranged from 2.1% in men aged 71 through 74 years to 33.4% in men aged 85 through 93 years. Age-standardized prevalence was 7.6%. Prevalence estimates for the cohort were 9.3% for dementia (all cause), 5.4% for Alzheimer disease (primary or contributing), and 4.2% for vascular dementia (primary or contributing). More than 1 possible cause was found in 26% of cases. The Alzheimer disease/vascular dementia ratio was 1.5 for cases attributed primarily to Alzheimer disease or vascular dementia. CONCLUSIONS: Prevalence of Alzheimer disease in older Japanese-American men in Hawaii appears to be higher than in Japan but similar to European-ancestry populations. Prevalence of vascular dementia appears to be slightly lower than in Japan, but higher than in European-ancestry populations. Further cross-national research with emphasis on standardized diagnostic methods is needed.

Age Distribution↗
PubMed1996

Observations on serum uric acid levels and the risk of idiopathic Parkinson's disease.

Uric acid, an antioxidant found in high concentrations in serum and in the brain, has been hypothesized to protect against oxidative damage and cell death in Parkinson's disease. The authors tested this hypothesis among men participating in a 30-year prospective study known as the Honolulu Heart Program. Serum uric acid was measured in 7,968 men at the baseline examination held from 1965 to 1968. Of these men, 92 subsequently developed idiopathic Parkinson's disease (IPD). In analyses adjusted for age and smoking, men with uric acid concentrations above the median at enrollment had a 40% reduction in IPD incidence (rate ratio (RR) = 0.6; 95% confidence interval (CI) 0.4-1.0). Reduced IPD incidence rates persisted in analyses restricted to nonsmokers (RR = 0.5; 95% CI 0.3-1.0) and cases younger than age 75 years (RR = 0.5; 95% CI 0.3-0.9). Incidence rates were not notably affected when analyses were restricted to cases that occurred more than 5 years after uric acid measurement (RR = 0.6; 95% CI 0.4-1.0). Inclusion of known or computed correlates of uric acid in regression models did not substantially change risk of IPD. This study provides prospective evidence of an association between uric acid and reduced occurrence of IPD and indicates that further investigations of this association are warranted.

Aged↗