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Dive into the research topics where Kamal Masaki is active.

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Featured researches published by Kamal Masaki.


JAMA | 2008

Ankle brachial index combined with Framingham risk score to predict cardiovascular events and mortality - A meta-analysis

Gerry Fowkes; F. G. R. Fowkes; Gordon Murray; Isabella Butcher; C. L. Heald; R. J. Lee; Lloyd E. Chambless; Aaron R. Folsom; Alan T. Hirsch; M. Dramaix; G DeBacker; J. C. Wautrecht; Marcel Kornitzer; Anne B. Newman; Mary Cushman; Kim Sutton-Tyrrell; Amanda Lee; Jacqueline F. Price; Ralph B. D'Agostino; Joanne M. Murabito; Paul Norman; K. Jamrozik; J. D. Curb; Kamal Masaki; Beatriz L. Rodriguez; J. M. Dekker; L.M. Bouter; Robert J. Heine; G. Nijpels; C. D. A. Stehouwer

CONTEXT Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction. OBJECTIVE To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction. DATA SOURCES Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies. STUDY SELECTION Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality. DATA EXTRACTION Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease. RESULTS Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women. CONCLUSION Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS.


Neurobiology of Aging | 2000

Midlife blood pressure and dementia: the Honolulu–Asia aging study☆ ☆

Lenore J. Launer; G. Webster Ross; Helen Petrovitch; Kamal Masaki; Dan Foley; Lon R. White; Richard J. Havlik

We studied the association of mid-life blood pressure to late age dementia, specifically Alzheimers disease and vascular dementia. Data are from the cohort of 3703 Japanese-American men who were followed in the Honolulu Heart Program (HHP;1965-1971), and subsequently re-examined in 1991 for dementia. We assessed the risk (odds ratio (95% CI)) for dementia associated with categories of systolic (SBP) and diastolic blood pressure (DBP), stratified by never/ever treatment with anti-hypertensive medications, and adjusting for age, education, apolipoprotein epsilon allele, smoking and alcohol intake. Among those never treated (57% sample), the risk for dementia was OR 95% CI 3.8 (1.6-8.7) for DBP of 90-94 mm Hg, and 4. 3 (1.7-10.8) for DBP of 95 mmHg and over compared to those with DBP of 80 to 89 mm Hg. Compared to those with SBP of 110 to 139 mm Hg, the risk for dementia was 4.8 (2.0-11.0) in those with SBP 160 mm Hg and higher. Blood pressure was not associated with the risk for dementia in treated men. These results were consistent for Alzheimers disease and vascular dementia. This study suggests elevated levels of blood pressure in middle age can increase the risk for late age dementia in men never treated with anti-hypertensive medication.


Journal of the American Geriatrics Society | 2005

Frailty: emergence and consequences in women aged 65 and older in the Women's Health Initiative Observational Study.

Nancy Fugate Woods; Andrea Z. LaCroix; Shelly L. Gray; Aaron Aragaki; Barbara B. Cochrane; Robert L. Brunner; Kamal Masaki; Anne Murray; Anne B. Newman

Objectives: To define frailty using simple indicators; to identify risk factors for frailty as targets for prevention; and to investigate the predictive validity of this frailty classification for death, hospitalization, hip fracture, and activity of daily living (ADL) disability.


Proceedings of the National Academy of Sciences of the United States of America | 2008

FOXO3A genotype is strongly associated with human longevity

Bradley J. Willcox; Timothy A. Donlon; Qimei He; Randi Chen; John S. Grove; Katsuhiko Yano; Kamal Masaki; D. Craig Willcox; Beatriz L. Rodriguez; J. David Curb

Human longevity is a complex phenotype with a significant familial component, yet little is known about its genetic antecedents. Increasing evidence from animal models suggests that the insulin/IGF-1 signaling (IIS) pathway is an important, evolutionarily conserved biological pathway that influences aging and longevity. However, to date human data have been scarce. Studies have been hampered by small sample sizes, lack of precise phenotyping, and population stratification, among other challenges. Therefore, to more precisely assess potential genetic contributions to human longevity from genes linked to IIS signaling, we chose a large, homogeneous, long-lived population of men well-characterized for aging phenotypes, and we performed a nested-case control study of 5 candidate longevity genes. Genetic variation within the FOXO3A gene was strongly associated with human longevity. The OR for homozygous minor vs. homozygous major alleles between the cases and controls was 2.75 (P = 0.00009; adjusted P = 0.00135). Long-lived men also presented several additional phenotypes linked to healthy aging, including lower prevalence of cancer and cardiovascular disease, better self-reported health, and high physical and cognitive function, despite significantly older ages than controls. Several of these aging phenotypes were associated with FOXO3A genotype. Long-lived men also exhibited several biological markers indicative of greater insulin sensitivity and this was associated with homozygosity for the FOXO3A GG genotype. Further exploration of the FOXO3A gene, human longevity and other aging phenotypes is warranted in other populations.


Neurology | 2001

Frequency of bowel movements and the future risk of Parkinson’s disease

Robert D. Abbott; Helen Petrovitch; Lon R. White; Kamal Masaki; Caroline M. Tanner; J. D. Curb; Andrew Grandinetti; P.L. Blanchette; J. S. Popper; G. W. Ross

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.


Annals of Neurology | 2002

Early inflammation and dementia: A 25-year follow-up of the Honolulu-Asia aging study†

Reinhold Schmidt; Helena Schmidt; J. David Curb; Kamal Masaki; Lon R. White; Lenore J. Launer

Inflammatory responses are associated with cardiovascular disease and may be associated with dementing disease. We evaluated the long‐term prospective association between dementia and high‐sensitivity C‐reactive protein, a nonspecific marker of inflammation. Data are from the cohort of Japanese American men who were seen in the second examination of the Honolulu Heart Program (1968–1970) and subsequently were reexamined 25 years later for dementia in the Honolulu‐Asia Aging Study (1991–1996). In a random subsample of 1,050 Honolulu‐Asia Aging Study cases and noncases, high‐sensitivity C‐reactive protein concentrations were measured from serum taken at the second examination; dementia was assessed in a clinical examination that included neuroimaging and neuropsychological testing and was evaluated using international criteria. Compared with men in the lowest quartile (<0.34mg/L) of high‐sensitivity C‐reactive protein, men in the upper three quartiles had a 3‐fold significantly increased risk for all dementias combined, Alzheimers disease, and vascular dementia. For vascular dementia, the risk increased with increasing quartile. These relations were independent of cardiovascular risk factors and disease. These data support the view that inflammatory markers may reflect not only peripheral disease, but also cerebral disease mechanisms related to dementia, and that these processes are measurable long before clinical symptoms appear.


Annals of Neurology | 2008

Association of olfactory dysfunction with risk for future Parkinson's disease

G. Webster Ross; Helen Petrovitch; Robert D. Abbott; Caroline M. Tanner; Jordan S. Popper; Kamal Masaki; Lenore J. Launer; Lon R. White

Although olfactory dysfunction is commonly associated with Parkinsons disease (PD), it is not known whether such dysfunction can predate the onset of clinical PD in a community‐based population. This study examines the association of olfactory dysfunction with future development of PD in Honolulu‐Asia Aging Study cohort members


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

BACKGROUND Population-based data are unavailable concerning the predictive value of orthostatic hypotension on mortality in ambulatory elderly patients, particularly minority groups. METHODS AND RESULTS With 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. CONCLUSIONS Orthostatic 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

BACKGROUND A 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. METHODS Lipid 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. FINDINGS Mean 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). INTERPRETATION We 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.


Neurology | 2000

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

Kamal Masaki; K.G. Losonczy; G. Izmirlian; Daniel J. Foley; G. W. Ross; Helen Petrovitch; Richard J. Havlik; Lon R. White

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.

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Lenore J. Launer

National Institutes of Health

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Beatriz L. Rodriguez

University of Hawaii at Manoa

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Bradley J. Willcox

University of Hawaii at Manoa

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J. David Curb

University of Hawaii at Manoa

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G. Webster Ross

University of Hawaii at Manoa

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Hirotsugu Ueshima

Shiga University of Medical Science

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Katsuyuki Miura

Shiga University of Medical Science

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Akira Sekikawa

University of Pittsburgh

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