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Featured researches published by Irwin J. Schatz.


Journal of the Neurological Sciences | 1999

Consensus statement on the diagnosis of multiple system atrophy

Sid Gilman; Phillip A. Low; N Quinn; Alberto Albanese; Yoav Ben-Shlomo; Clare J. Fowler; Horacio Kaufmann; Thomas Klockgether; Anthony E. Lang; P.L Lantos; Irene Litvan; Christopher J. Mathias; Oliver E; David Robertson; Irwin J. Schatz; Gregor K. Wenning

We report the results of a consensus conference on the diagnosis of multiple system atrophy (MSA). We describe the clinical features of the disease, which include four domains: autonomic failure/urinary dysfunction, parkinsonism and cerebellar ataxia, and corticospinal dysfunction. We set criteria to define the relative importance of these features. The diagnosis of possible MSA requires one criterion plus two features from separate other domains. The diagnosis of probable MSA requires the criterion for autonomic failure/urinary dysfunction plus poorly levodopa responsive parkinsonism or cerebellar ataxia. The diagnosis of definite MSA requires pathological confirmation.


Circulation | 1998

Orthostatic hypotension predicts mortality in elderly men : the Honolulu Heart Program

Kamal Masaki; Irwin J. Schatz; Cecil M. Burchfiel; Dan S. Sharp; D Chiu; Foley D; Curb Jd

BACKGROUNDnPopulation-based data are unavailable concerning the predictive value of orthostatic hypotension on mortality in ambulatory elderly patients, particularly minority groups.nnnMETHODS AND RESULTSnWith the use of data from the Honolulu Heart Programs fourth examination (1991 to 1993), orthostatic hypotension was assessed in relation to subsequent 4-year all-cause mortality among a cohort of 3522 Japanese American men 71 to 93 years old. Blood pressure was measured in the supine position and after 3 minutes of standing, with the use of standardized methods. Orthostatic hypotension was defined as a drop in systolic blood pressure (SBP) of >/=20 mm Hg or in diastolic blood pressure of >/=10 mm Hg. Overall prevalence of orthostatic hypotension was 6.9% and increased with age. There was a total of 473 deaths in the cohort over 4 years; of those who died, 52 had orthostatic hypotension. Four-year age-adjusted mortality rates in those with and without orthostatic hypotension were 56.6 and 38.6 per 1000 person-years, respectively. With the use of Cox proportional hazards models, after adjustment for age, smoking, diabetes mellitus, body mass index, physical activity, seated systolic blood pressure, antihypertensive medications, hematocrit, alcohol intake, and prevalent stroke, coronary heart disease and cancer, orthostatic hypotension was a significant independent predictor of 4-year all-cause mortality (relative risk 1.64, 95% CI 1.19 to 2.26). There was a significant linear association between change in systolic blood pressure from supine position to standing and 4-year mortality rates (test for linear trend, P<0.001), suggesting a dose-response relation.nnnCONCLUSIONSnOrthostatic hypotension is relatively uncommon, may be a marker for physical frailty, and is a significant independent predictor of 4-year all-cause mortality in this cohort of elderly ambulatory men.


The Lancet | 2001

Cholesterol and all-cause mortality in elderly people from the Honolulu Heart Program: a cohort study

Irwin J. Schatz; Kamal Masaki; Katsuhiko Yano; Randi Chen; Beatriz L. Rodriguez; J. David Curb

BACKGROUNDnA generally held belief is that cholesterol concentrations should be kept low to lessen the risk of cardiovascular disease. However, studies of the relation between serum cholesterol and all-cause mortality in elderly people have shown contrasting results. To investigate these discrepancies, we did a longitudinal assessment of changes in both lipid and serum cholesterol concentrations over 20 years, and compared them with mortality.nnnMETHODSnLipid and serum cholesterol concentrations were measured in 3572 Japanese/American men (aged 71-93 years) as part of the Honolulu Heart Program. We compared changes in these concentrations over 20 years with all-cause mortality using three different Cox proportional hazards models.nnnFINDINGSnMean cholesterol fell significantly with increasing age. Age-adjusted mortality rates were 68.3, 48.9, 41.1, and 43.3 for the first to fourth quartiles of cholesterol concentrations, respectively. Relative risks for mortality were 0.72 (95% CI 0.60-0.87), 0.60 (0.49-0.74), and 0.65 (0.53-0.80), in the second, third, and fourth quartiles, respectively, with quartile 1 as reference. A Cox proportional hazard model assessed changes in cholesterol concentrations between examinations three and four. Only the group with low cholesterol concentration at both examinations had a significant association with mortality (risk ratio 1.64, 95% CI 1.13-2.36).nnnINTERPRETATIONnWe have been unable to explain our results. These data cast doubt on the scientific justification for lowering cholesterol to very low concentrations (<4.65 mmol/L) in elderly people.


The Lancet | 2001

Observations on recurrent syncope and presyncope in 641 patients

Christopher J. Mathias; Kazushi Deguchi; Irwin J. Schatz

BACKGROUNDnSyncope is a common disorder that is potentially disabling and affects both young and old. Once neurological, cardiological, and metabolic causes have been excluded, there remains a group in which diagnosis is unclear; some may have an autonomic basis. We therefore did a retrospective study on consecutive patients referred to our tertiary referral autonomic centres between 1992 and 1998 with recurrent syncope and presyncope, in whom non-autonomic causes, before referral, had been sought and excluded. The object was to find out whether autonomic investigation helped diagnosis.nnnMETHODSnData from case notes and from the autonomic database on 641 patients were analysed. Syncopal patients with a known or provisional diagnosis of autonomic failure were excluded from analysis. The role of screening tests in establishing or excluding an autonomic cause was assessed. Response to additional autonomic tests (such as head-up tilt with or without venepuncture, and food challenge and exercise) was documented. Some patients underwent further testing if non-autonomic neurological, psychiatric, and other disorders were considered.nnnFINDINGSnScreening autonomic function tests indicated orthostatic hypotension and confirmed chronic autonomic failure in 31 (4.8%) patients. Neurally mediated syncope was diagnosed in 279 (43.5%) on the basis of clinical features and autonomic testing. Most had vasovagal syncope (227 [35%]); other causes included carotid sinus hypersensitivity (37 [5.8%]), and a group of 15 (2.3%) were associated with rarer causes such as micturition and swallowing. Miscellaneous cardiovascular causes (systemic hypotension, arrhythmias), or drugs, contributed to syncope in 53 (8.3%). Non-autonomic neurological causes included vestibular dysfunction (32 [5%]) and epilepsy (11 [1.7%]). In 56 (8.7%) a psychiatric cause was thought to be contributory. In 179 (27.9%), syncope was of unknown cause.nnnINTERPRETATIONnIn recurrent syncope and presyncope, when cardiac, neurological, and metabolic causes have been excluded, autonomic investigation can aid management by making, confirming, or excluding various factors or diagnoses.


American Journal of Cardiology | 2000

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

Robert D. Abbott; Helen Petrovitch; Beatriz L. Rodriguez; Katsuhiko Yano; Irwin J. Schatz; Jordan S. Popper; Kamal Masaki; G. Webster Ross; J. David Curb

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.


Journal of Clinical Epidemiology | 2001

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

Robert D. Abbott; Beatriz L. Rodriguez; Helen Petrovitch; Katsuhiko Yano; Irwin J. Schatz; Jordan S. Popper; Kamal Masaki; G. Webster Ross; J. David Curb

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.


Annals of Epidemiology | 2002

Age-Related Changes in Risk Factor Effects on the Incidence of Coronary Heart Disease

Robert D. Abbott; J. David Curb; Beatriz L. Rodriguez; Kamal Masaki; Katsuhiko Yano; Irwin J. Schatz; G. Webster Ross; Helen Petrovitch

PURPOSEnThe purpose of this report is to examine the potential for risk factor effects on the incidence of CHD to change over a broad range of ages from middle adulthood to late-life.nnnMETHODSnFindings are based on repeated risk factor measurements at four examinations over a 26-year period in men enrolled in the Honolulu Heart Program. After each examination, six years of follow-up were available to assess risk factor effects as the cohort aged from 45 to 93 years.nnnRESULTSnBased on 18,456 person intervals of follow-up, 677 men developed CHD (3.7%). After risk factor adjustment, a positive relation between hypertension and CHD declined significantly with age (p = 0.013), primarily due to a large increase in the risk of CHD in elderly men (75 to 93) without hypertension. Effects of total cholesterol on CHD also seemed to decline with advancing age, although changes were not statistically significant. In contrast, men with diabetes had a consistent 2-fold excess risk of CHD across all age groups, while a positive association with body mass index in younger men (45 to 54) became negative in those who were the oldest (75 to 93). Due to infrequent smoking in the elderly, associations between smoking and CHD weakened with age. In the oldest men (75 to 93), alcohol intake was unrelated to CHD, while effects of sedentary life-styles on promoting CHD appeared stronger than in those who were younger.nnnCONCLUSIONnFindings suggest that changes in risk factor effects on the incidence of CHD with advancing age may require updated strategies for CHD prevention as aging occurs.


Clinical Cardiology | 2009

A Comparison of Echocardiographic Findings in Young Adults With Cardiomyopathy: With and Without a History of Methamphetamine Abuse

Hiroki Ito; Khung-Keong Yeo; Mevan Wijetunga; Todd B. Seto; Kevin Tay; Irwin J. Schatz

Methamphetamine is currently the most widespread illegal stimulant abused in the United States. No previous reports comparing echocardiographic findings of cardiomyopathy with and without a history of methamphetamine abuse are available.


Clinical Autonomic Research | 2007

Impaired glucose tolerance is associated with postganglionic sudomotor impairment

Andrew Grandinetti; David M. Sletten; Jared K. Oyama; Andre Theriault; Irwin J. Schatz; Phillip A. Low

We compared quantitative sudomotor axon-reflex test responses in persons with normal and impaired glucose tolerance (IGT). Responses were significantly impaired in those with IGT, which may be indicative of early distal small fiber neuropathy.


Journal of the American Geriatrics Society | 2004

Prospective association between low and high total and low-density lipoprotein cholesterol and coronary heart disease in elderly men.

J. David Curb; Robert D. Abbott; Beatriz L. Rodriguez; Kamal Masaki; Jordan S. Popper; Randi Chen; Helen Petrovitch; Patricia L. Blanchette; Irwin J. Schatz; Katsuhiko Yano

Objectives: To examine the relationship between total cholesterol (TC) and low‐density lipoprotein cholesterol (LDL‐C) and the incidence of coronary heart disease (CHD) in elderly men.

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Kamal Masaki

University of Hawaii at Manoa

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J. David Curb

University of Hawaii at Manoa

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Beatriz L. Rodriguez

University of Hawaii at Manoa

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Andrew Grandinetti

University of Hawaii at Manoa

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Helen Petrovitch

University of Hawaii at Manoa

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Robert D. Abbott

Shiga University of Medical Science

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Andre Theriault

University of Hawaii at Manoa

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Cecil M. Burchfiel

National Institute for Occupational Safety and Health

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