Factors Associated with Lower Cognitive Performance Scores Among Older Japanese Men in Hawaii and Japan.

BACKGROUND: Few studies have compared factors related to cognitive function among people with similar genetic backgrounds but different lifestyles. OBJECTIVE: We aimed to identify factors related to lower cognitive scores among older Japanese men in two genetically similar cohorts exposed to different lifestyle factors. METHODS: This cross-sectional study of community-dwelling Japanese men aged 71-81 years included 2,628 men enrolled in the Kuakini Honolulu-Asia Aging Study based in Hawaii and 349 men in the Shiga Epidemiological Study of Subclinical Atherosclerosis based in Japan. We compared participant performance through Cognitive Abilities Screening Instrument (CASI) assessment in Hawaii (1991-1993) and Japan (2009-2014). Factors related to low cognitive scores (history of cardiovascular disease, cardiometabolic factors, and lifestyle factors) were identified with questionnaires and measurements. Multivariable logistic regression analysis was used to calculate the adjusted odds ratios (ORs) of a low (< 82) CASI score based on different factors. RESULTS: CASI scores were lower in Hawaii than in Japan [21.2%(n = 556) versus 12.3%(n = 43), p < 0.001], though this was not significant when adjusted for age and educational attainment (Hawaii 20.3%versus Japan 17.9%, p = 0.328). History of stroke (OR = 1.65, 95%confidence interval = 1.19-2.29) was positively associated with low cognitive scores in Hawaii. Body mass index ≥25 kg/m2 tended to be associated with low cognitive scores in Japan; there was a significant interaction between the cohorts. CONCLUSION: Cognitive scores differences between cohorts were mostly explained by differences in educational attainment. Conversely, cardiovascular diseases and cardiometabolic factors differentially impacted cognitive scores among genetically similar older men exposed to different lifestyle factors.

Total and differential white blood cell counts in late life predict 8-year incident stroke: the Honolulu Heart Program.

OBJECTIVES: To study the association between total and differential white blood cell (WBC) count and incident stroke in an older Asian population. DESIGN: Prospective population-based study with 8 years of follow-up. SETTING: The Honolulu Heart Program, Oahu, Hawaii. PARTICIPANTS: Japanese-American men aged 71 to 93 who were free of stroke and had baseline WBC counts measured in 1991-93 (N=3,342). MEASUREMENTS: Participants were divided into quartiles of total and differential WBC count for analysis and were followed for incident stroke (thromboembolic and hemorrhagic (hemorrhagic)) for 8 years using data from a comprehensive hospital surveillance system. RESULTS: Age-adjusted incident stroke rates increased significantly with increasing WBC quartile (Q1, 7.68; Q2, 9.04; Q3, 9.26; Q4, 14.10 per 1,000 person-years of follow-up, P=.001). Hazard ratios (HRs) for stroke for each quartile of total and differential WBC count were obtained using Cox regression analysis, with the lowest quartile as the reference group. After full adjustment, including age; cardiovascular risk factors; fibrinogen; prevalent coronary heart disease, cancer, or chronic obstructive pulmonary disease, and nonsteroidal anti-inflammatory drug use, HRs were 1.62 (95% confidence interval (CI)=1.04-2.52, P=.03) in the highest quartile of total WBC and 2.19 (95% CI=1.41-3.39, P<.001) in the highest quartile of neutrophil counts. Significant associations were also seen for thromboembolic but not for hemorrhagic strokes. No significant associations were found between lymphocyte or monocyte counts and incident stroke or subtypes. CONCLUSION: In elderly Japanese-American men, higher total WBC and neutrophil counts were independent predictors of overall stroke, as well as thromboembolic stroke.

Proteinuria in midlife and 39-year total mortality: the Honolulu Heart Program.

BACKGROUND: Previous population-based studies have shown that proteinuria is an independent predictor of total mortality. However, no studies have examined multiple proteinuria measurements or had a follow-up period longer than two decades. METHODS: Proteinuria was measured by urine dipstick on 6,815 Japanese-American men on two occasions, 6 years apart. Participants were classified into the "no proteinuria" group if both examinations were negative, "transient proteinuria" if either was positive, and "persistent proteinuria" if both were positive and followed for total mortality over 39 years. RESULTS: Prevalence of transient and persistent proteinuria was 6.4% and 1.3%, respectively. Age-adjusted total mortality rates were 41.9, 55.0, and 71.9 per 1000 person-years follow-up for no, transient, and persistent proteinuria groups, respectively (p for trend <.0001). Multivariate Cox proportional hazards models showed increased total mortality risk in a dose-response manner: HR, 1.40; P < .001 and HR, 2.26; P < .001 for transient and persistent proteinuria groups, respectively (using no proteinuria as reference). Stratified analyses showed stronger associations between proteinuria and mortality among those with prevalent cardiovascular diseases compared with those without. CONCLUSIONS: Proteinuria was independently associated with higher total mortality risk over 39 years. This risk was stronger among high-risk populations but also remained significant in low-risk populations. Simple urine dipstick can be a good risk assessment tool in the general population.

Lifestyle and the risk of dementia in Japanese-american men.

OBJECTIVES: To determine whether adhering to a healthy lifestyle in midlife may reduce the risk of dementia. DESIGN: Case-control study nested in a prospective cohort. SETTING: The Honolulu-Asia Aging Study, Oahu, Hawaii. PARTICIPANTS: Three thousand four hundred sixty-eight Japanese-American men (mean age 52 in 1965-1968) examined for dementia 25 years later. MEASUREMENTS: Men at low risk were defined as those with the following midlife characteristics: nonsmoking, body mass index (BMI) less than 25.0 kg/m(2) , physically active, and having a healthy diet (based on alcohol, dairy, meat, fish, fruits, vegetables, cereals, and ratio of monounsaturated to saturated fat). Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for developing overall dementia, Alzheimer's disease (AD), and vascular dementia (VaD), adjusting for potential confounders. RESULTS: Dementia was diagnosed in 6.4% of men (52.5% with AD, 35.0% with VaD). Examining the risk factors individually, BMI was most strongly associated with greater risk of overall dementia (OR = 1.87, 95% CI = 1.26-2.77; BMI > 25.0 vs <22.6 kg/m(2) ). All of the individual risk factors except diet score were significantly associated with VaD, whereas none were significantly associated with AD alone. Men with all four low-risk characteristics (7.2% of the cohort) had the lowest OR for overall dementia (OR = 0.36, 95% CI = 0.15-0.84). There were no significant associations between the combined low-risk characteristics and the risk of AD alone. CONCLUSION: Among Japanese-American men, having a healthy lifestyle in midlife is associated with a lower risk of dementia in late life.