[Epidemiological study of preferable life style for psychological health promotion]

OBJECTIVE

We sought to examine relationships of lifestyle factors, including diet, physical activity, sleep, alcohol consumption and smoking, with perceived stress and depressive symptoms.

METHODS

Between 2001 and 2002, 7,947 men and women (mean 52.4 years) took part in examinations at the Osaka Medical Center for Health Science and Promotion. Lifestyle factors were determined by structured interview or by self-administered questionnaire. Associations of life style factors with perceived stress and depressive symptoms were tested by stepwise logistic regression analyses.

RESULTS

Higher proportions of persons with depressive symptoms tended to be associated with higher proportions of persons with perceived stress. Among both men and women, low physical activity, lack of regular physical exercise, short sleeping time, to skip breakfast frequently, and having dinner within a couple of hours before going to bed were associated with both perceived stress and depressive symptoms. Men reporting between-meal or midnight snacks and having eating until they were full had higher odds ratios for perceived stress, while men conducting regular physical exercise and consuming 3 or more dishes of vegetables per day had lower odds ratios for depressive symptoms. For women, high odds ratios for depressive symptoms and perceived stress were observed among those who tended to have salty foods (or frequent use of soy sauce) and a lower odds ratio for perceived stress was noted among persons who had soy products every day.

CONCLUSION

Lifestyle facets such as skipping breakfast, low physical activity, and short sleeping time, appear to be associated with psychological health status of Japanese men and women.

Aldosterone Synthase Gene T-344C Polymorphism, Sodium and Blood Pressure in a Free-Living Population: A Community-Based Study

There have been few epidemiological studies on the gene-environmental interaction between the aldosterone synthase gene (CYP11B2) T-344C polymorphism and sodium in relation to blood pressure in a free-living general population. We hypothesized a priori that persons with the T allele of CYP11B2 would have elevated blood pressure levels in response to a higher sodium intake, and thus the association between the T-344C polymorphism and blood pressure would be more evident among persons with a high sodium intake than among those with a low sodium intake. Study subjects were 2,823 men and women aged 30-74 in a Japanese community. We examined the associations between the T-344C polymorphism and blood pressure levels, stratified by sodium variables estimated by 24-h urinary sodium excretion and a dietary questionnaire. There was no significant difference in blood pressure levels among the CC, TC and TT groups for either or both sexes. However, among persons with higher sodium excretion, mean systolic blood pressure levels tended to be higher in those with the TC (+3.0 mmHg, p=0.06) and TT (+2.9 mmHg, p=0.07) genotypes than in those with the CC genotype, but this tendency was not seen among those with lower sodium excretion (-4.0 mmHg, p=0.03 for TC vs. CC; -3.0 mmHg, p=0.11 for TT vs. CC; p for interaction =0.006). In conclusion, we found no association between CYP11B2 and blood pressure for total subjects or for persons with a higher sodium intake. However, a possible gene-blood pressure association among persons with higher sodium intake needs to be explored further.

G-protein beta-3 subunit C825T polymorphism, sodium and arterial blood pressure: a community-based study of Japanese men and women

Epidemiological evidence on gene-environment effects of the G-protein beta-3 subunit C825T polymorphisms and sodium on blood pressure in the free-living general population is limited. We examined the associations between the C825T polymorphism and blood pressure levels, stratified by the sodium variables estimated by 24-h urinary sodium excretion and a dietary questionnaire, among 1,471 men and women aged 30-74 from a community in Japan. Our a priori hypothesis was that individuals with the 825T allele have elevated blood pressure among subjects with a high sodium intake. Among the whole group, the systolic blood pressure level was +2.2 mmHg (p = 0.10) higher in TT than CC genotype individuals after adjustment for sex, age, antihypertensive medication use, body mass index, and alcohol consumption. This difference was more evident among individuals with low sodium excretion (+4.5 mmHg, p = 0.01), low present sodium intake (+3.2 mmHg, p = 0.11), and low past sodium intake (+4.8 mmHg, p = 0.02). No associations were observed among those with high sodium variables. Our results indicate that the G-protein beta-3 subunit C825T polymorphism is associated with higher systolic blood pressure levels in a large free-living Japanese population, and more specifically in women with a low sodium intake. This finding helps to explain part of the discrepancy between the previously reported genetic association among different ethnic groups.

Relationship of smoking and smoking cessation with ankle-to-arm blood pressure index in elderly Japanese men

BACKGROUND

Cigarette smoking is associated with an increased risk of peripheral arterial disease, but the relationship between smoking cessation and preclinical peripheral atherosclerosis is uncertain.

DESIGN AND METHODS

A cross-sectional, population-based study to examine the effect of smoking and smoking cessation on the prevalence of peripheral arterial disease among 1215 men aged 60-79 years in two Japanese communities in 1999-2000. The ankle-to-arm systolic blood pressure index (AAI) was used as an estimate of the presence of peripheral atherosclerosis.

RESULTS

The mean AAI correlated inversely and linearly with smoking status and pack-years of smoking. The multivariate prevalence odds ratio [95% confidence interval (CI)] of low AAI (< 0.90) compared with never-smokers was 3.7 (95% CI 1.1-12.7) for current smokers and 4.2 (95% CI 1.2-14.6) for men with 45 or more pack-years of smoking. In men who have quit smoking for 20 years or more, the mean AAI was higher and the prevalence of low AAI (< 0.90) was lower than those of current smokers, but similar to those of never-smokers.

CONCLUSIONS

Our results confirm that current smoking and pack-years of smoking correlate with the presence of peripheral artery disease. The results suggest that smoking cessation for 20 years or more is associated with the regression of atherosclerosis in peripheral arteries. This finding needs to be confirmed by a prospective study.

Leukocyte count is an independent predictor for risk of acute myocardial infarction in middle-aged Japanese men

BACKGROUND

Leukocyte count is recognized as an inflammatory marker and a predictor of cardiovascular events. However, it is uncertain whether the contribution of leukocyte count to the risk of cardiovascular disease is independent of smoking.

METHODS

The subjects were 4492 male employees aged 40-59 years who worked for nine companies in Osaka.

RESULTS

After 9-year follow-up, 40 acute myocardial infarction and 26 ischemic stroke events occurred. Age-adjusted relative risk of acute myocardial infarction in the highest versus lowest quartiles of leukocyte count was 6.0 (95% CI, 1.8-20.5, P for trend <0.001) and the multivariable relative risk adjusted for smoking and other conventional cardiovascular risk factors was 3.7 (1.0-13.4, P for trend=0.01). The association between leukocyte count and the risk of acute myocardial infarction was also observed among both current smokers and nonsmokers. The positive association between leukocyte count and the risk of ischemic stroke was weak and did not reach statistical significance.

CONCLUSIONS

Leukocyte count is a predictor of acute myocardial infarction among Japanese middle-aged men, both in smokers and nonsmokers.

Plasma Fibrinogen Concentrations and Risk of Stroke and Its Subtypes Among Japanese Men and Women

BACKGROUND AND PURPOSE

We aimed to examine the impact of fibrinogen concentrations on the incidence of stroke.

METHODS

We examined the association between fibrinogen and risk of total stroke and stroke subtypes in an 11-year prospective study of 4608 men and 7589 women aged 40 to 79 years with no history of stroke and/or coronary heart disease. The analysis was repeated, stratified by smoking status, to examine whether the association between fibrinogen and stroke was modified by smoking.

RESULTS

There were 317 incident total strokes comprising 103 hemorrhagic strokes (70 intraparenchymal hemorrhages [22.1% of strokes], 33 subarachnoid hemorrhages [10.4%]), 206 ischemic strokes (65.0%), and 8 strokes of undetermined type (2.5%). The multivariable hazard ratio (95% CI) for the highest versus lowest fibrinogen quartiles after adjustment for age, sex, area, and known cardiovascular risk factors was 2.5 (1.3 to 5.0), P<0.01, for hemorrhagic stroke and 3.2 (1.4 to 7.4), P<0.01, for intraparenchymal hemorrhage. There was no positive association of fibrinogen with risk of ischemic stroke or subarachnoid hemorrhage. Among never-smokers, the multivariable hazard ratio (95% CI) for the highest versus lowest fibrinogen quartiles was 3.5 (1.3 to 9.3), P=0.01, for hemorrhagic stroke and 4.4 (1.3 to 15.2), P=0.02, for intraparenchymal hemorrhage.

CONCLUSIONS

High plasma fibrinogen concentration can be a predictor for risk of intraparenchymal hemorrhage.

[Individualized health education with sports gym use and dietary advice for overweight and obese persons in a community. Kokuho Health-up model Program in Chikusei-shi (former Kyowa town)]

OBJECTIVE

We aimed to evaluate the effect of a community-based health educational program for overweight or obesity persons, as the Kokuho Health-up model Program in Kyowa area of Chikusei-shi.

METHODS

The subjects were men and women aged 35 to 60 years who participated in annual health check-ups from 1998 to 2003 and were living in Chikusei-shi (Former Kyowa town) Ibaraki prefecture, had a body mass index > or = 25.0 kg/m2 at baseline, and agreed to a 6-month intervention. The participants were divided into 59 persons for the intense intervention group (health checkups, dietary advice, monthly individual health education, and exercise in sports facilities three times/ week), 62 persons for the moderate intervention group (health checkups, dietary advice, monthly individual health education, and exercise in sports facilities or at home once/week), and 34 persons for the control group (only health checkups). Criteria for the metabolic syndrome were those published by the Japanese 8 committee.

RESULT

During the 6-month intervention, the follow-up rate was 86%. At the baseline, there were no differences in physical status or lifestyles among the intervention and control groups. The frequency of use of sports facilities was 6.4 times/month for the intense intervention group and 1.9 times/month for the moderate intervention group. Mean body weight did not change in the control group (70.6 kg to 70.9 kg, P = 0.84) but decreased in the intense intervention group (71.4 kg to 69.5 kg, P < 0.001) and moderate intervention group (69.5 kg to 66.7 kg, P < 0.001). Mean abdominal circumference increased in the control group (91.0 cm to 93.9 cm, P = 0.001) but did not change in intense intervention group (90.1 cm to 90.0 cm, P = 0.29) or moderate intervention group (90.4 cm to 88.7 cm, P = 0.39). The prevalence of metabolic syndrome increased in the control group (18.2% to 40.0%, P = 0.01) but did not change in either of the intervention groups.

CONCLUSIONS

We found a significant reduction of body weight and an attenuation of the increase of metabolic syndrome in both intensive and moderate intervention groups. The present community-based educational program may be effective for health promotion with overweight or obese middle-aged adults.

[Evaluation of a community-based health education program for salt reduction through media campaigns]

PURPOSE

To provide the strategies, achievement and evaluation of a community health education program for salt reduction with media campaigns.

METHODS

The intervention community was Kyowa town (A district of Chikusei city, census population in 1985 = 16,792) where we have systematically conducted a community-based blood pressure control program since 1981, and health education on reduction of salt intake since 1983 for primary prevention of hypertension. The education program was performed through media campaigns including use of banners, signboards, posters, and calendars with health catchphrases. We also used catchphrase-labeled envelopes when sending documents from the municipal health center to individuals. Health festivals were held annually to enhance health consciousnesses and to improve health behavior. Some of the posters and calligraphy were painted or drawn by elementary schoolchildren as part of their education. The program was evaluated by repeated questionnaires and examination of salt concentrations of miso soup and dietary salt intake.

RESULTS

Between 1983 and 1988, the prevalence of persons who were aware that health consultation including blood pressure measurements were available at the town office increased from 65% to 84%. The prevalence of those who knew the salt intake goal (10 g or less/day) increased from 47% to 63% and that of those who reported to reduce salt intake also increased from 38% to 58%. As for salt concentrations of miso soup, the proportion with less than 1.1% increased from 47% to 66% between 1985 and 2004. Age-adjusted mean salt intake for persons aged 40-69 years declined from 14 g to 11 g in men and from 12 g to 10 g in women between 1982-1986 and 2000-2004.

CONCLUSION

A long-term systemic education program through media campaigns proved feasible with the cooperation of community leaders, schools and food associations.

Proportions of Stroke Subtypes Among Men and Women ≥40 Years of Age in an Urban Japanese City in 1992, 1997, and 2002

Background and Purpose— Higher proportions of hemorrhagic stroke and lacunar infarction were reported in rural Japan compared with those in Western countries. We examined the relative proportions of stroke subtypes in an urban Japanese city where westernized lifestyles are more common than in rural areas.

Methods— Stroke registration was performed in 1992, 1997, and 2002 for residents ≥40 years of age who were admitted with acute strokes to all of the 10 hospitals with ≥90 beds in Yao City, Osaka, Japan. Strokes were classified as intraparenchymal hemorrhage, subarachnoid hemorrhage, or ischemic strokes (embolic infarction, large-artery occlusive infarction, lacunar infarction, and unclassified thrombotic infarction) by criteria using computed tomography or MRI.

Results— A total of 650 first-ever strokes were registered. The age-adjusted proportion of each stroke subtype was not significantly different among the 3 study periods in both men and women. Throughout the 3 periods, intraparenchymal hemorrhage, subarachnoid hemorrhage, and ischemic stroke accounted for 26%, 7%, and 65% in men, respectively. In women, the respective proportions were 29%, 21%, and 44%. The proportion of each subtype for total ischemic strokes was as follows: 51% to 61% lacunar infarction, 25% to 26% large-artery occlusive infarction, and 11% to 17% embolic infarction.

Conclusions— Our study showed that hemorrhagic stroke represented a large proportion of all strokes, especially among women, and lacunar infarction was the most common subtype of ischemic stroke among both men and women in Yao City, which differed from findings in Western countries.

The relationship between sleep-disordered breathing and high-sensitivity C-reactive protein in Japanese men

STUDY OBJECTIVES

Elevated C-reactive protein (CRP), an inflammatory marker and emerging risk factor for atherosclerosis and coronary heart disease, has been reported in overweight patients with sleep-disordered breathing (SDB). However, the contribution of C-reactive protein to this disease among non-overweight individuals is uncertain. We thus examined the relationship between serum C-reactive protein levels and nocturnal arterial oxygen desaturation, stratified by category of body mass index (BMI).

DESIGN

Cross-sectional study.

PARTICIPANTS

Subjects were 316 men with a mean BMI of 25.4 kg/m2, aged 20-79 years, who attended a sleep clinic at Osaka, Japan.

MEASUREMENTS AND RESULTS

SDB was assessed by oxygen desaturation index (ODI) measured by pulse oximetry during sleep. We used 3% oxygen desaturations per hour (3% ODI), as the indicator of SDB. We also measured serum levels of C-reactive protein (CRP). After adjustment for age, BMI, hypertension, diabetes mellitus, hypercholesterolemia, smoking status, alcohol consumption, and daily sleep duration, mean high-sensitivity CRP levels were 0.63, 0.65, and 0.96 mg/L for SDB severity levels of 3%ODI<5, 5 to 19.9, and >=20, respectively (p for trend=0.015). This association with SDB tended to be stronger in non-overweight men (BMI<25 kg/m2) (0.47, 0.48 and 1.02 mg/L, p for trend=0.017) than in overweight men (BMI > or = 25 kg/m2) (0.92, 0.87 and 1.21 mg/L, p for trend=0.11).

CONCLUSION

SDB is associated with increased levels of CRP, especially in non-overweight men. Our results suggest the importance of follow-up and control of SDB in the prevention of cardiovascular disease even in non-overweight SDB patients.

Metabolic syndrome and urinary cGMP excretion in general population

To examine the relationship between metabolic syndrome and endothelial dysfunction, we investigated cross-sectionally the correlation between metabolic risk factors and urinary excretion of cyclic guanosine 3',5'-monophosphate (cGMP), a second messenger of nitric oxide (NO), in 1541 Japanese men and women aged 40-79 years. The 24-h urinary excretion of cGMP was measured using a (125)I-labeled cGMP radioimmunoassay and was adjusted for urinary creatinine excretion (nmol/mmol creatinine). The components of metabolic syndrome were defined based on the following criteria: body mass index (BMI)> or =25.0 kg/m(2), fasting plasma glucose> or =6.11 mmol/l or non-fasting plasma glucose level> or =11.1 mmol/l, systolic blood pressure> or =130 mm Hg or diastolic blood pressure> or =85 mm Hg, high-density lipoprotein (HDL)-cholesterol<1.03 mmol/l for men and <1.29 mmol/l for women, and triglyceride> or =1.69 mmol/l. The number of components of metabolic syndrome correlated inversely with urinary cGMP excretion; means of cGMP excretion for the whole group adjusted for age, sex, and cardiovascular risk factors were 53.6, 48.6, 47.9, 44.4 and 42.3 nmol/mmol for 0, 1, 2, 3, and 4-5 components of metabolic syndrome, respectively (p=0.002). Our data suggest that a reduction of NO bioactivity concur with clustered features of the metabolic syndrome.

Ankle-arm blood pressure index as a correlate of preclinical carotid atherosclerosis in elderly Japanese men

Peripheral artery disease correlates with preclinical carotid atherosclerosis in Western populations. However, little is known about this correlation in Asian populations. In a cross-sectional population-based study, we examined the correlation between peripheral arterial disease and carotid intima-media thickness (IMT) among 726 Japanese men aged 60-79 years. None of them had a history of clinical peripheral arterial disease. The ankle-to-arm systolic blood pressure index (AAI) was used as a surrogate estimate of peripheral arterial disease. Compared to men with AAI> or =0.90, those with AAI<0.90 were 1-4 years older, and had lower mean body mass index and higher prevalence of current smokers. The mean AAI correlated inversely and linearly with maximum IMT in the common and internal carotid arteries (CCA and ICA), and men with AAI<0.90 had higher prevalence of maximum ICA IMT > or =1.5mm than did those with AAI> or =0.90. The multivariate odds ratio (95% confidence interval) of maximum ICA IMT > or =1.5mm was 2.9 (1.0-8.4), while that of maximum CCA IMT> or =1.1mm was 1.4 (0.5-3.8) for men with AAI<0.90 versus > or =1.30. The sensitivity was 65% and the specificity was 98% for low AAI to detect ICA IMT > or =1.5mm. Low AAI is a strong correlate for internal carotid atherosclerosis and the AAI measurement may be of use to screen for preclinical peripheral atherosclerosis among Japanese elderly men.

Hepatosplenic αβ T-cell lymphoma with myelodysplastic syndrome

We describe a patient with hepatosplenic 33 T-cell lymphoma who showed pancytopenia and myelodysplasia. A 35-year-old man was admitted with fever, pancytopenia, and hepatosplenomegaly but with no lymphadenopathy. We also found trilineage myelodysplasia in the bone marrow on his first admission. The patient had high fever and anemia but no evidence of infection and was tentatively treated with prednisolone. This treatment resulted in a transient improvement of the cytopenia and a reduction of spleen size. However, 10 months after the first manifestation, progression of the splenomegaly and fever became apparent, and a splenectomy was performed. The pathologic findings for the spleen showed diffuse and disseminated infiltration of medium- to large-sized T-lymphocytes in the splenic red pulp. These cells were immunohistochemically positive for CD3, CD5, CD7, CD8, CD16, CD56,T-cell receptor 33 (TCR33),T-cell intracellular antigen 1, and granzyme B but were negative for CD4, CD30, CD57, and TCR33. These data suggested a diagnosis of hepatosplenic 33 T-cell lymphoma. A Southern blot analysis revealed gene rearrangement of the TCR 3-chain gene but not the immunoglobulin heavy chain gene in the spleen cells. An in situ hybridization analysis for the Epstein-Barr virus revealed negative results. The patient received 8 courses of combination chemotherapy and achieved a partial remission; however, the dysplastic features of the marrow cells persisted after the partial remission was obtained. Additional treatment with allogeneic bone marrow transplantation resulted in a transient complete remission; however, the patient relapsed 11 months later. Because he had experienced no lymphadenopathy and showed dysplastic features in the bone marrow, the diagnosis was highly dependent on the pathologic findings for the resected spleen.

Evaluation of coronary artery calcification by multi-detector row computed tomography for the detection of coronary artery stenosis in Japanese patients

BACKGROUND

The development of an efficient noninvasive examination to detect coronary atherosclerosis is needed as a strategy to prevent coronary heart disease. To evaluate the usefulness of calcium score measured by multi-detector row computed tomography (MDCT), we compared calcium score derived from MDCT with findings of coronary artery stenosis assessed by coronary angiography (CAG).

METHODS

In 108 patients (94 men, 14 women; average age, 65.7 years), we performed unenhanced CT scans and calculated coronary artery calcium score in 259 vessels without previous intervention and severe motion artifact to determine the correlation with the degree of coronary stenosis by CAG.

RESULTS

The sensitivity and the specificity of calcification (calcium score 0.1+) for severe stenosis (75+%) were 89% and 43%, respectively. All four vessels with calcium score 1000+ had a severe stenosis. The areas under the receiver operating characteristics curve of calcium score for severe stenosis were 0.80 +/- 0.04, indicating the efficacy of this technique.

CONCLUSIONS

Coronary artery calcification and calcium score determined by MDCT were associated with coronary arteries with severe stenosis. This technique appears to be useful for the evaluation of coronary atherosclerosis.

Clonal T cells of pure red-cell aplasia

This study detected clonal T cells in patients with acquired pure red-cell aplasia (PRCA) by Southern blotting and polymerase chain reaction (PCR). Twenty-nine adult patients with acquired PRCA were enrolled in this study. Seventeen patients had primary acquired PRCA, while 12 patients had the secondary form. Twenty-two of 29 (76%) patients demonstrated TCR rearrangement by at least one method. We divided the patients into three groups depending on T-cell clonality. The CD4/8 ratio of patients who were positive on Southern blotting was significantly lower than that of other groups. Except for the CD4/8 ratio, other laboratory findings did not significantly differ among the three groups. The CD4/8 ratio should be a useful surrogate marker to detect T-cell clonality.

Trends in dietary intake of folate, vitamins B6, and B12 among Japanese adults in two rural communities from 1974 through 2001

BACKGROUND: The 5th edition of the Japanese food composition table enables us to evaluate intakes of folate and vitamins B₆ and B₁₂, which are associated with risk of chronic diseases.

METHODS: We investigated long-term trends in dietary intake of those nutrients in two rural communities; Ikawa from 1974 through 2000, and Kyowa from 1982 through 2001. The 24-hour recall method was adopted. Intake of green tea interviewed from 1994 was used to examine food sources for these nutrients in the latest period, but not to evaluate long-term trends. Reduced intakes of nutrients due to cooking were not taken into account.

RESULTS: Age-adjusted mean folate intake increased by 30% in Ikawa between the 1970’s and 1980’s, and then leveled off to the latest survey, while that in Kyowa did not change throughout the survey periods. The increased folate intake was primarily due to green/yellow vegetables. Mean vitamin B₆ intake did not change except that it increased for Ikawa women in the 1980’s and decreased for Kyowa men in the latest period. No secular trend was found for mean vitamin B₁₂ intake. The largest source for folate intake was total vegetables (38-58% of total intake) and the second largest source was alcohol/beverages including green tea (11-24%). Fish/shellfish was the largest source for vitamins B₆ (16-23%) and B₁₂ (77-84%).

CONCLUSIONS: Dietary intakes of folate, vitamins B₆ and B₁₂ showed no notable long-term trend, except for an increased folate intake between the 1970’s and 1980’s due to an increased intake of green/yellow vegetables.

Methylation of p15(INK4b) and E-cadherin genes is independently correlated with poor prognosis in acute myeloid leukemia

Hypermethylation of CpG islands is a common mechanism by which tumor suppressor genes are inactivated. The tumor suppressor gene p15(INK4b) is important component of cell cycles, whereas E-cadherin gene is often termed a metastasis suppressor gene. We have studied the feasibility of detecting tumor-associated aberrant p15(INK4b) and E-cadherin methylation in acute myeloid leukemia (AML) using methylation-specific PCR. Aberrant methylation of p15(INK4b) was detected in 31 of 61 (51%) AML patients. On the other hand, E-cadherin hypermethylation was detected in 36 of 61 (56%) AML patients. We have examined the methylation pattern of these genes and the prognosis in AML patients using a log-rank test. Methylation of p15(INK4b) gene significantly correlated with prognosis (p=0.0012), and methylation of E-cadherin gene more significantly correlated with prognosis (p=0.0004). When both were methylated, there was even more significant unfavorable prognosis compared to either of the methylated genes (p<0.0001). We interpret these data to mean that dysfunction of the cell cycle and/or the cell-cell adhesion molecule plays a role in the pathogenesis of acute myeloid leukemia and that analysis of the methylation of p15(INK4b) and E-cadherin genes can provide clinically important evidence on which to base treatment.

Relationship between urinary cGMP excretion and serum total cholesterol levels in a general population

Hypercholesterolemia impairs endothelial function. However, the critical level of serum total cholesterol at which endothelial dysfunction occurs is unknown at present. We investigated cross-sectionally the correlation between urinary excretion of cyclic guanosine 3',5' monophosphate (cGMP), a second messenger of nitric oxide (NO) and serum total cholesterol concentrations in a general population sample of Japanese men and women. The samples comprised 1541 subjects (788 men and 753 women) aged 40-79 years, who participated in cardiovascular risk surveys between 1997 and 2002 and underwent a 24h urine collection. Urinary excretion of cGMP was measured using a (125)I-labeled cGMP radioimmunoassay and was adjusted for urinary creatinine excretion (nmol/mmol creatinine). The mean urinary cGMP excretion correlated linearly and inversely with serum total cholesterol level: mean cGMP excretion adjusted for age, sex and cardiovascular risk factors was 61.7, 53.6, 50.8, 49.2, 47.3 and 46.4 nmol/mmol for total cholesterol levels <4.14, 4.14-4.64, 4.65-5.16, 5.17-5.68, 5.69-6.20 and > or =6.21 mmol/L, respectively (p=0.007). This relation was more evident among individuals with end-organ damage, among subjects with higher C-reactive protein (CRP) levels and among postmenopausal women. Our data suggest a reduction of NO bioactivity with higher serum total cholesterol levels, even within clinically normal cholesterol levels.

Carotid Intima-Media Thickness and Plaque Characteristics as a Risk Factor for Stroke in Japanese Elderly Men

BACKGROUND AND PURPOSE

Few cohort studies have examined the association of carotid intima-media thickness (IMT) and plaque characteristics with the risk of stroke in apparently healthy persons. We examined the relationship of carotid IMT and the surface, morphology, and calcification of carotid plaques with the incidence of stroke among Japanese men.

METHODS

Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 1289 men aged 60 to 74 years without a previous stroke or coronary heart disease. In this cohort, the subsequent incidence of stroke was investigated.

RESULTS

During the 4.5-year follow-up, 34 strokes occurred. The multivariate-adjusted relative risk (95% CI) for the highest versus lowest quartiles of maximum IMT of the common carotid artery (CCA; > or =1.07 versus < or =0.77 mm) was 3.0 (1.1 to 8.3) for stroke. The combination of CCA and internal carotid artery (ICA) wall thickness was a better predictor of the risk of stroke than was CCA wall thickness alone. Men with a plaque, defined as a focal wall thickness of > or =1.5 mm, in the ICA had a 3-fold higher risk of stroke than those without a plaque, and the plaque surface irregularity further increased the stroke risk. A significant excess risk of stroke was confined to men with an uncalcified plaque.

CONCLUSIONS

Increased IMT of the CCA and an uncalcified plaque in the ICA, as assessed by ultrasonography, are risk factors for stroke in elderly Japanese men.

Type 2 diabetes and risk of non-embolic ischaemic stroke in Japanese men and women

AIMS/HYPOTHESIS

The aim of this study was to examine the relationship between type 2 diabetes and risk of ischaemic stroke in Asian populations.

METHODS

We conducted a 17-year prospective cohort study in 10,582 Japanese individuals (4287 men and 6295 women) aged 40-69 years living in five communities in Japan. All subjects were free of stroke and CHD at baseline. Diabetes was defined as a fasting glucose level of >/=7.0 mmol/l, a non-fasting glucose of >/=11.1 mmol/l, or receiving medication for diabetes.

RESULTS

The risk of non-embolic ischaemic stroke was approximately two-fold higher in diabetic subjects than in subjects with normal glucose levels. The multivariate relative risk after adjustment for age, community, hypertensive status, BMI, triceps and subscapular skinfold thickness (TSF and SSF), and other known cardiovascular risk factors was 1.8 (95% CI 1.0-3.2) for men and 2.2 (1.2-4.0) for women. This excess risk was primarily observed among non-hypertensive subjects and individuals with higher values for measures of adiposity (BMI, TSF and SSF values above the median), particularly those with higher values for SSF. The association between non-embolic ischaemic stroke and glucose abnormality was particularly strong among non-hypertensive subjects with higher SSF values: the multivariate relative risk was 1.9 (1.0-3.7) for borderline diabetes and 4.9 (2.5-9.5) for diabetes.

CONCLUSIONS/INTERPRETATION

In this cohort, type 2 diabetes was a significant risk factor for non-embolic ischaemic stroke, particularly in non-hypertensive and non-lean individuals. Due to the nationwide decrease in blood pressure and increase in mean BMI among the Japanese population, with current levels approaching those observed in Western countries, the impact of glucose abnormalities on risk of ischaemic stroke represents a forthcoming public health issue in Japan.