LIGHT, a member of the tumor necrosis factor ligand superfamily, prevents tumor necrosis factor-alpha-mediated human primary hepatocyte apoptosis, but not Fas-mediated apoptosis

LIGHT is a member of tumor necrosis factor (TNF) superfamily, and its receptors have been identified as lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/ATAR/TR2, both of which lack the cytoplasmic sequence termed the "death domain." The present study has demonstrated that LIGHT inhibits TNFalpha-mediated apoptosis of human primary hepatocytes sensitized by actinomycin D (ActD), but not Fas- or TRAIL-mediated apoptosis. Furthermore, LIGHT does not prevent some cell lines such as HepG2 or HeLa from undergoing ActD/TNFalpha-induced apoptosis. This protective effect requires LIGHT pretreatment at least 3 h prior to ActD sensitization. LIGHT stimulates nuclear factor-kappaB (NF-kappaB)-dependent transcriptional activity in human hepatocytes like TNFalpha. The time course of NF-kappaB activation after LIGHT administration is similar to that of the pretreatment required for the anti-apoptotic effect of LIGHT. LIGHT inhibits caspase-3 processing on the apoptotic protease cascade in TNFalpha-mediated apoptosis but not Fas-mediated apoptosis. In addition, increased caspase-3 and caspase-8 activities in ActD/TNFalpha-treated cells are effectively blocked by LIGHT pretreatment. However, LIGHT does not change the expression of TNFRp55, TNFRp75, and Fas. These results indicate that LIGHT may act as an anti-apoptotic agent against TNFalpha-mediated liver injury by blocking the activation of both caspase-3 and caspase-8.

Medical care expenditure associated with body mass index in Japan: the Ohsaki Study

OBJECTIVE

To examine the impact of body mass index (BMI) upon medical care use and its costs in Japan.

DESIGN

A population-based prospective cohort study from 1995 to 1998.

SUBJECTS

A cohort of 41 967 Japanese adults aged 40-79 y. Subjects who died during the first year of follow-up, or who at baseline reported having had cancer, myocardial infarction, stroke or kidney disease were excluded.

MEASUREMENTS

Medical care use and its costs, actual charges, by linkage with the National Health Insurance claim history files after adjustment of smoking, drinking and physical functioning status.

RESULTS

There was a U-shaped association between BMI and total medical costs. The nadir of the curve was found at a BMI of 21.0-22.9 kg/m(2). Relative to the nadir, total costs were 9.8% greater among those with BMIs of 25.0-29.9 (rate ratio, 1.10; 95% confidence interval (CI), 1.03-1.17), and 22.3% greater among those with BMIs of 30.0 or higher (rate ratio, 1.22; 95% CI, 1.08-1.37). Estimated excess direct costs attributable to overweight (BMI of 25.0-29.9 kg/m(2)) and obesity (BMI of 30.0 kg/m(2) or higher) represent 3.2% of total health expenditure in the present study, which is within the range reported in Western countries (0.7-6.8%).

CONCLUSION

Our prospective data demonstrate that the impact of overweight and obesity upon medical care costs in Japan is as large as in Western countries, despite the much lower mean BMI in Japanese populations.

Food frequency questionnaire and a screening test

We assessed the accuracy of a 141-item food frequency questionnaire as a screening test to detect high or low consumption of nutrients associated with cancer. Fifty-five men and 58 women participating in two population-based cohort studies in Miyagi, Japan, provided four three-day diet records over a one-year period and subsequently completed the questionnaire twice with a one-year interval. Pearson correlation coefficients between 17 nutrients measured by the diet records and the first questionnaire ranged from 0.24 to 0.85 (median 0.43), and those between the two questionnaires ranged from 0.47 to 0.91 (median 0.68). The sensitivity and specificity of the questionnaire for detecting high-alcohol, high-fat, low-calcium, and low-ascorbic acid consumers were 86.7% and 96.7%, 50.0% and 85.7%, 48.8% and 76.4%, and 61.9% and 70.0%, respectively. Receiver operating characteristic curves indicated comparable performance of the questionnaire and a three-day diet record, regarded as another screening test. The questionnaire performed poorly for other nutrients. The results indicate that our questionnaire is reasonably reproducible, comparable with the diet records, and useful as a screening test to detect high or low consumers of several nutrients associated with cancer for subsequent enrollment in dietary intervention trials or dietary counseling.

Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women

OBJECTIVES

To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.

METHODS

The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.

RESULTS

The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.

CONCLUSIONS

These results show that passive smoking may affect the risk of cancers other than lung cancer.

LIGHT, a member of the TNF superfamily, induces morphological changes and delays proliferation in the human rhabdomyosarcoma cell line RD

LIGHT is a member of the tumor necrosis factor (TNF) superfamily, which binds two known receptors, lymphotoxin-beta receptor (LTbetaR) and the herpesvirus entry mediator (HVEM)/TR2. We investigated the effects of LIGHT on the human rhabdmyosarcoma cell line RD. LIGHT delayed cell proliferation and induced morphological changes of the cells. These effects were not shown by other TNF family ligands such as TNFalpha and LTalpha, which induced the transcriptional activity of nuclear factor-kappaB (NF-kappaB) and NF-kappaB-responsible chemokine productions in the same manner as did LIGHT. LTalpha1beta2, another TNF family ligand for LTbetaR, was shown to have similar activities in RD cells as LIGHT. Both LIGHT and LTalpha1beta2 induced the expression of muscle-specific genes such as smooth muscle (SM) alpha-actin, while TNFalpha and LTalpha did not. These findings indicate that LIGHT may be a novel inducer of RD cell differentiation associated with SM alpha-actin expression through the LTbetaR.

Aldosterone synthase gene (CYP11B2) C-334T polymorphism, ambulatory blood pressure and nocturnal decline in blood pressure in the general Japanese population: the Ohasama Study

OBJECTIVE

The C-344T polymorphism in the 5'-flanking region of the aldosterone synthase (CYP11B2) gene has been suggested to be associated with hypertension and disturbed circadian blood pressure (BP) rhythm through its effect on aldosterone synthesis. However, previous findings on this topic have been inconsistent.

DESIGN

A cross-sectional study.

SUBJECTS AND METHODS

We investigated the CYP11B2 C-344T genotype in 802 subjects, aged 40 and over, in a Japanese community, who gave written informed consent and were monitored for 24 h ambulatory BP.

RESULTS

The frequencies of the CC, CT, and TT genotypes in these Japanese subjects were 0.14, 0.44, and 0.42, showing a higher frequency of the T allele (0.64) than in Caucasians. Although there was no significant difference in 24 h ambulatory BP levels among the genotypes, the nocturnal decline in BP was significantly greater in the CC homozygous subjects than in other subjects (P = 0.0065 for systolic and P = 0.031 for diastolic decline in nocturnal BP). Detailed analyses demonstrated that this association was significant only in aged (60 years and over) or male subjects. The prevalence of previous cardiovascular disease was significantly less in these subjects with the CC genotype than in those with the TC and TT genotypes, although age, body mass index, male gender, smoking, use of alcohol and antihypertensive medication did not differ among the three genotypes. There was no significant difference among the three genotypes in biochemical and hormonal parameters.

CONCLUSION

Although the C-344 T polymorphism of CYP11B2 did not directly influence the level of 24 h BP, the CC genotype was associated with decreased nocturnal BP in elderly or male Japanese. Since prevalence of previous cardiovascular disease was significantly less in homozygous CC subjects, greater nocturnal BP decline in this genotype appears to be beneficial in the circadian BP rhythm.

Predictive values of automated blood pressure measurement: what can we learn from the Japanese population - the Ohasama study

BACKGROUND

Measurements of ambulatory blood pressure (ABP) and of home blood pressure (HBP) as an adjunct to casual/clinic blood pressure (CBP) measurements are currently widely used for the diagnosis and treatment of hypertension. We have monitored a rural cohort of people from the population of Ohasama, Japan, with respect to their prognosis and have previously reported that ABP and HBP are superior to CBP for the prediction of cardiovascular mortality. One reason that CBP is a poor predictor of prognosis is that it incorporates several biases, including the white-coat effect.

METHODS AND RESULTS

We examined the prognostic significance of white-coat hypertension for mortality and found that the relative hazard for the overall mortality of patients with white-coat hypertension was significantly lower than that for true hypertension. Short-term blood pressure variability has recently attracted attention as a cause of target-organ damage and cardiovascular complications. Our results confirmed that short-term blood pressure variability (as measured every 30 min) was independently associated with cardiovascular mortality. In addition, research has recently focused on isolated systolic hypertension and pulse pressure as independent risk factors for poor cardiovascular prognosis. The Ohasama study also clearly demonstrated that isolated systolic hypertension and increased pulse pressure, as assessed by HBP, were associated with an increase in the risk of cardiovascular mortality. Circadian blood pressure variation is characterized by a diurnal elevation and a nocturnal decline in blood pressure. We therefore compared morbidity from stroke between dippers (subjects who show an ordinal nocturnal dipping of blood pressure) and non-dippers (those with a diminished nocturnal dipping or nocturnal elevation of blood pressure [inverted dippers]) in the Ohasama study. The incidence of stroke increased with an increased length of observation in dippers using antihypertensive medication but not in non-dippers using antihypertensive medication. In contrast, the relative hazard for mortality increased in non-dippers and inverted dippers. These results suggest a cause-and-effect relationship for both dippers and non-dippers.

CONCLUSION

The Ohasama study showed that the level and variability of hypertension as assessed by ABP and HBP are independent predictors of cardiovascular mortality. It also demonstrated an independent association between the prognosis of hypertension and each component of ABP and HBP, indicating the prognostic significance of these blood pressure measurements.

Endothelin-1 gene variant associates with blood pressure in obese Japanese subjects: the Ohasama Study

A recent report based on the results of 2 epidemiological studies, the Etude Cas-Temoin de l'Infarctus Myocarde (ECTIM) and the Glasgow Heart Scan Study, revealed that a G/T polymorphism with an amino acid substitution (Lys-->Asn) at codon 198 in exon 5 of the endothelin-1 gene (ET-1) is associated with blood pressure in overweight people. They suggested that G/T polymorphism of ET-1 strongly interacted with body mass index (BMI) in the determination of BP levels. To examine interaction among G/T polymorphism of ET-1, BMI, and BP, we performed an association study in a general Japanese population. Subjects (n=1250) were recruited from Ohasama, a cohort in a rural community of northern Japan. DNA was extracted from buffy coat of participants, and G/T polymorphism of ET-1 was determined by the TaqMan probe polymerase chain reaction method, a powerful tool for semiautomatic genotype determination of a large number of samples. Frequency of T (Asn 198) allele in Japanese (27%) was slightly but significantly higher than in whites (24%). Baseline characteristics (age, BMI, systolic and diastolic BP, and antihypertensive treatment) of all subjects were not significantly different according to the genotype of G/T polymorphism. However, in obese subjects (> or =25 kg/m(2)) diastolic BPs were significantly associated with G/T polymorphism of ET-1. After adjustment for confounding factors, significant association remained; for overweight subjects, diastolic BP level in those with T allele (GT + TT) was 1.8 mm Hg (P=0.04) higher than in those with GG genotype. That similar results were obtained from subjects of different races suggests that the Lys198Asn polymorphism of ET-1 is involved in determination of BP levels in obese subjects.

Passive smoking at home and cancer risk: a population-based prospective study in Japanese nonsmoking women

OBJECTIVES

To investigate the relationship between passive smoking at home and the incidence of various cancers in a population-based prospective study.

METHODS

The subjects were 9675 Japanese lifelong nonsmoking women aged over 40 years who lived in three municipalities of Miyagi Prefecture, and completed a self-administration questionnaire in 1984. During 9 years of follow-up, 426 cancers were identified by record linkage to the population-based cancer registry. The data were analyzed using the Cox proportional hazards model.

RESULTS

The age-adjusted relative risks (RR) and 95% confidence intervals (CI) of smoking-related cancers and lung cancer for women who had smoking husbands, compared with women whose husbands did not smoke, were 1.7 (0.94 2.9, p = 0.079) and 1.9 (0.81-4.4, p = 0.14), respectively. In contrast, a significant inverse association was observed for breast cancer, the RR (95% CI) was 0.58 (0.34-0.99, p = 0.047). After multivariate adjustment for confounding factors, the risks of smoking-related cancers and breast cancer were materially unchanged.

CONCLUSIONS

These results show that passive smoking may affect the risk of cancers other than lung cancer.

A case-control study for evaluating the efficacy of mass screening program for lung cancer in Miyagi Prefecture, Japan

BACKGROUND

In Miyagi Prefecture, Japan, a mass screening program for lung cancer has been conducted since 1982 (miniature chest X-ray for all screenees and sputum cytology for those with a smoking index > or = 600) [smoking index 600 = 30 pack years, the average number of cigarettes smoked per day multiplied by the number of years of regular smoking]. Over 1500 lung carcinomas, including 250 roentgenographically occult lung tumors, were detected and treated up to 1999. In the current study, a nested case-control study was conducted in the population that was screened in 1989 to evaluate the efficacy of the screening program for lung cancer.

METHODS

To reduce self-selection bias, the source population was defined as screenees with negative results in 1989 (284,226 individuals). In the population, 474 individuals died of lung carcinoma during 1992-1994. After exclusion, 328 patients who died of primary lung carcinoma at between ages 40 years and 79 years were defined as the cases. Six controls were supposed to be selected in the source population for each case and matched by gender, year of birth, municipality, and smoking habits. Controls who had died or moved before the matched case was diagnosed were excluded. Finally, 328 cases and 1886 controls were selected. Screening histories were compared, and odds ratios were calculated using conditional logistic regression analysis.

RESULTS

Within the 12 months before diagnosis, 241 of 328 cases (73.5%) had attended the screening compared with 1557 of 1886 controls (82.6%). The smoking-adjusted odds ratio was 0.54 (95% confidence interval, 0.41-0.73).

CONCLUSIONS

The mass screening program for lung cancer in Miyagi Prefecture was capable of reducing by 46% the risk of death from carcinoma of the lung.

A novel secreted tumor antigen with a glycosylphosphatidylinositol-anchored structure ubiquitously expressed in human cancers

In a search for novel genes expressed in human cancers, we identified one gene from an assembled expressed sequence tag database. Northern blot analysis revealed that the gene, termed alcan, was expressed in various types of human cancer cell lines and in the fetus, but not in normal tissues. The alcan gene is located on chromosome 6 and is encoded on a 246-amino-acid protein with weak homology to classical major histocompatibility complex class I. Its gene product, ALCAN, had hydrophobic amino acid clusters at both the N- and C-terminal regions and was predicted to be a glycosylphosphatidylinositol (GPI)-anchored membrane protein. Flow cytometric analysis revealed that ALCAN was detected on the surface of human cancer cells and on alcan-transfected CHO-K1 cells. ALCAN was also secreted from these cells, suggesting that some portion of the molecules was secreted by enzymatic cleavage by, for example, phospholipases. Mutational analysis of ALCAN suggested that the GPI-anchored position was the Ser(216) residue. These findings indicate that ALCAN may be a potential target for cancer diagnosis or therapy.

Effects of exercise training on home blood pressure values in older adults: a randomized controlled trial

OBJECTIVE

To determine the effects of exercise training on the blood pressure (BP) values of older adults, using home blood pressure measurement.

DESIGN

Randomized controlled trial.

PARTICIPANTS

A total of thirty-nine free-living older adults (including 19 men) aged from 60-81 years with home systolic blood pressure > 120 mmHg and without significant cardiopulmonary-musculoskeletal disease, were randomly allocated to either 25 weeks of exercise training (exercise group) or to a control program (control group).

MAIN OUTCOME MEASUREMENTS

Change in the 2-week averages of home systolic and diastolic blood pressure values measured with a validated automatic device before, during and after the intervention period.

RESULTS

Compared with the control group, the exercise group showed a significant decrease in values for home systolic blood pressure (maximum between-group difference = 7.7 mmHg, P = 0.003) and home diastolic blood pressure (4.2 mmHg, P = 0.001). These changes were observed for both genders.

CONCLUSIONS

Exercise training was effective for older adults in lowering home blood pressure values. This is the first trial to demonstrate the usefulness of home blood pressure measurement in examining the effect of exercise training on blood pressure values.

Impact of smoking habit on medical care use and its costs: a prospective observation of National Health Insurance beneficiaries in Japan

BACKGROUND

To quantify excess medical use associated with smoking, a large prospective cohort study is needed. The authors examined the impact of smoking on medical care use in a large population-based cohort with an accurate data collecting system in Japan.

METHOD

The data were derived from a 30-month prospective cohort study of 43,408 National Health Insurance beneficiaries aged 40--79 years living in a rural Japanese community. The smoking habit of beneficiaries was assessed in a baseline survey at the end of 1994. Medical care use and its costs were monitored by linkage with the National Health Insurance claim history files since January 1995.

RESULTS

Male smokers incurred 11% more medical costs (after adjustment for age, physical functioning status, alcohol consumption, body mass index and average time spent walking) than 'never smokers' but for female smokers and never smokers the costs were almost the same. This difference was mainly attributable to increased use of inpatient medical care among smokers, especially in males, where per month cost of inpatient care was 33% higher in smokers. Age-group specific analysis in men showed that excess mortality and excess medical cost ratio for smokers peaked in those aged 60--69 years.

CONCLUSIONS

Smokers consume excess medical care. Among the population aged 45 years and over, about 4% of total medical costs were attributable to smoking. To pursue both better health and lower medical costs for the nation, a comprehensive programme to reduce tobacco use is needed.

[Active life expectancy: factors influencing regional and gender differences]

Active life expectancy (ALE) is defined as an expected duration to be spent with a certain level of physical/mental function. The objectives of this article are to indicate ALE values based on our prospective observation, and to discuss factors influencing regional and gender differences in ALE values. We estimated ALE without disability in basic activities of daily living (ADL) on a 5% random sample (n = 3,459) of the residents aged 65 years and over in Sendai City between 1988 and 1991. At the age 65, ALE was 14.7 years for men and 17.7 years for women. ALE occupied 91% of the total life expectancy for men and 87% for women. As compared with the reports for the American elderly, ALE was longer in Sendai than in the United States. The duration to be spent with disability was shorter among the subjects in Sendai. We estimated ALEs in three functional areas: basic ADL, instrumental ADL, and mobility, on all the residents aged 65 years and over (n = 3,590) at Wakuya Town between 1994 and 1996. For both sexes, ALE in IADL was shorter than those in basic ADL and mobility. The development and progression of disability were different between sexes: men experienced disability at a younger age and progressed at a faster rate than women.

Green tea and the risk of gastric cancer in Japan

BACKGROUND

Although laboratory experiments and case-control studies have suggested that the consumption of green tea provides protection against gastric cancer, few prospective studies have been performed.

METHODS

In January 1984, a total of 26,311 residents in three municipalities of Miyagi Prefecture, in northern Japan (11,902 men and 14,409 women 40 years of age or older), completed a self-administered questionnaire that included questions about the frequency of consumption of green tea. During 199,748 person-years of follow-up, through December 1992, we identified 419 cases of gastric cancer (in 296 men and 123 women). We used Cox regression to estimate the relative risk of gastric cancer according to the consumption of green tea.

RESULTS

Green-tea consumption was not associated with the risk of gastric cancer. After adjustment for sex, age, presence or absence of a history of peptic ulcer smoking status, alcohol consumption, other dietary elements, and type of health insurance, the relative risks associated with drinking one or two, three or four, and five or more cups of green tea per day, as compared with less than one cup per day, were 1.1 (95 percent confidence interval, 0.8 to 1.6), 1.0 (95 percent confidence interval, 0.7 to 1.4), and 1.2 (95 percent confidence interval, 0.9 to 1.6), respectively (P for trend=0.13). The results were similar after the 117 cases of gastric cancer that were diagnosed in the first three years of follow-up had been excluded, with respective relative risks of 1.2 (95 percent confidence interval, 0.8 to 1.8) 1.0 (95 percent confidence interval, 0.7 to 1.5), and 1.4 (95 percent confidence interval, 1.0 to 1.9) (P for trend=0.07).

CONCLUSIONS

In a population-based, prospective cohort study in Japan, we found no association between green-tea consumption and the risk of gastric cancer.

Usefulness of home blood pressure measurements in assessing the effect of treatment in a single-blind placebo-controlled open trial

OBJECTIVES

Reproducibility of home blood pressure measurements (HBP), and the placebo effect on HBP, were examined to establish the number of subjects required in order to observe a significant antihypertensive effect of a drug for a comparative study between placebo and active treatment.

METHODS

Reproducibility of HBP (n = 172 for systolic blood pressure and n = 137 for diastolic blood pressure) and the placebo effect on HBP (n = 35 for systolic and n = 42 for diastolic blood pressure) were examined using a semi-automatic electronic device on untreated hypertensive subjects during 21 consecutive days of measurements. From these two studies, the number of subjects required in order to observe a significant antihypertensive drug effect was assessed. In both studies, measurements from the first 3 days were excluded from the analysis.

RESULTS

Reproducibility, defined as the difference between the initial 5 day average (days 4-8) and the last 5 day average (days 17-21) was -1.9 +/- 7.0/-1.4 +/- 4.8 mmHg (mean +/- SD), indicating high reproducibility with a minimal regression to the mean effect. A placebo was administered after the 8 day run-in period. The difference between the initial 5 day average (days 4-8) and the last 5 day average (days 17-21) was compared. The mean difference was 1.1 +/- 6.2/0.2 +/- 5.7 mmHg, suggesting that there was a minimal, if any, placebo effect. As determined by the power calculations, based on the standard deviations of the tests for reproducibility and the placebo effect, nine of 13 subjects are required to show that a 9/5 mmHg decrease in systolic HBP/diastolic HBP (50% of estimated effective decrease in systolic HBP/diastolic HBP according to the guidelines for clinical trials in Japan) is statistically significant

CONCLUSIONS

The results suggest that the HBP measurement is highly reproducible and that there is a minimal, if any, placebo effect. These characteristics of HBP contribute to minimizing the number of subjects necessary for assessment of antihypertensive drug effects in comparative studies between an active treatment and placebo.

Risk factors and predictors of coronary arterial lesions in Japanese hypertensive patients

The morbidity rate of coronary artery disease has recently increased in Japan. This is attributable to changes from traditional to more westernized lifestyles. In this study, we therefore examined the risk factors and predictors of coronary arterial lesions in Japanese patients with essential hypertension. Coronary angiography was performed in 109 consecutive essential hypertension patients (57 men and 52 women; 66 +/- 8.0 years of age) with either angina pectoris or atypical chest pain, who were chosen from 485 consecutive hypertensive patients in a hypertension clinic in Sendai, Japan. Coronary arterial stenosis of greater than 50% was defined as significant and used as a dependent variable for the multiple regression analysis. Risk factors were defined as factors confirmed to have a causal relationship with coronary arterial lesions, whereas arteriosclerotic complications and hypertensive target organ damage were defined as predictors. Multiple logistic regression analysis was performed using these parameters as independent variables. Of 109 patients, 25 had a coronary arterial stenosis greater than 50%. A smoking habit (odds ratio (OR): 4.48; 95% confidence interval (CI): 1.13-17.82; p<0.05), hypercholesterolemia (OR: 5.34; 95% CI: 1.52-18.73; p<0.05), and 24-h diastolic blood pressure (OR: 2.33; 95% CI: 1.06-5.16; p<0.05) were significant risk factors, whereas carotid intima-media thickness (OR: 5.85; 95% CI: 1.48-23.2; p<0.05) was a significant predictor of coronary arterial lesion. When two of the major risk factors (a smoking habit, hypercholesterolemia, or impaired glucose tolerance including diabetes mellitus) were clustered in addition to the hypertension, the risk of coronary arterial lesions increased by 6.7 to 10.1 times. These findings indicate that the major risk factors established in Caucasians, i.e., a smoking habit, hypercholesterolemia and blood pressure level, are also risk factors for coronary arterial lesions in Japanese with essential hypertension. The presence of two or more risk factors increases the risk of coronary arterial lesions synergistically in the presence of hypertension.

Factors affecting the difference between screening and home blood pressure measurements: the Ohasama Study

OBJECTIVE

To establish the factors affecting the difference between screening and home blood pressure measurements.

DESIGN

A cross-sectional study.

SETTING

General population in a rural Japanese community, Ohasama, Japan.

PARTICIPANTS

There were 1,789 community-based subjects aged > or =40 years, for whom blood pressure was measured at screening site (screening blood pressure) and at home (home blood pressure).

RESULTS

Multiple stepwise regression analysis of all subjects demonstrated that screening pulse pressure was positively associated with the difference between screening and home blood pressure measurements for systolic blood pressure. Age, the use of antihypertensive medication, and smoking status were negatively associated with the difference between measurements of both systolic and diastolic blood pressure.

CONCLUSION

We have demonstrated that age, smoking, antihypertensive medication, and screening pulse pressure are independent predictors of the magnitude of the difference between screening and home blood pressure measurements, suggesting that the necessity to consider these factors, for the detection of the subjects who may be inappropriately treated or misjudged following screening blood pressure measurements.

Prognosis of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure at home: the Ohasama study

BACKGROUND

Although the clinical significance of systolic-diastolic hypertension and isolated systolic hypertension has been established, the significance of isolated diastolic hypertension has not been fully investigated.

OBJECTIVE

To clarify the prognostic significance of isolated systolic and isolated diastolic hypertension as assessed by self-measurement of blood pressure (BP) at home (home BP measurements), which has a better reproducibility and prognostic value than casual BP measurements in the general population.

SUBJECTS AND METHODS

We obtained home BP measurements for 1913 subjects aged 40 years or older, then followed up their survival status (mean, 8.6 years). We classified the subjects into the following 4 groups according to their home BP levels: systolic-diastolic hypertension, isolated systolic hypertension, isolated diastolic hypertension, and normotension. The prognostic significance of each type of hypertension for the risk of cardiovascular mortality risk was investigated using a Cox proportional hazards regression model adjusted for possible confounding factors.

RESULTS

The risk for isolated systolic hypertension and systolic-diastolic hypertension were significantly higher than the relative hazard for normotension, while isolated diastolic hypertension was associated with no significant increase in risk. Home pulse pressure measurement was also independently associated with an increase in the risk of cardiovascular mortality.

CONCLUSIONS

Isolated diastolic hypertension, as assessed by home BP measurements, carried a low risk of cardiovascular mortality, similar to that found in subjects with normotension, suggesting that the prognosis of hypertension would be improved by treatment focused on systolic rather than on diastolic home BP measurements. To our knowledge, this study is the first to demonstrate the clinical significance of pulse pressure as assessed by home BP measurement. Arch Intern Med. 2000;160:3301-3306.

Prognostic significance of blood pressure and heart rate variabilities: the Ohasama study

To investigate the association between cardiovascular mortality and short-term variabilities in blood pressure and heart rate, we performed a long-term prospective study of ambulatory blood pressure monitoring in Ohasama, Japan, starting in 1987. We obtained ambulatory blood pressure and heart rate in 1542 subjects >/=40 years of age. Blood pressure and heart rate variabilities were estimated as a standard deviation measured every 30 minutes by ambulatory monitoring. There were 67 cardiovascular deaths during the follow-up period (mean=8.5 years). The Cox proportional hazards model, adjusted for possible confounding factors, demonstrated a significant increase in cardiovascular mortality, with an increase in daytime systolic ambulatory blood pressure variability. A similar trend was observed in daytime diastolic and nighttime ambulatory blood pressures. Cardiovascular mortality rate increased linearly, with a decrease in daytime heart rate variability. Subjects in whom the daytime systolic ambulatory blood pressure variability was larger than third quintile and the daytime heart rate variability was lower than the mean-SD were at extremely high risk of cardiovascular mortality. The blood pressure and heart rate variabilities obtained every 30 minutes by ambulatory blood pressure monitoring were independent predictors for cardiovascular mortality in the general population.

The effect of heparin on tissue factor and tissue factor pathway inhibitor in patients with acute myocardial infarction

We examined plasma TF and free TFPI levels in 26 consecutive patients with AMI, 26 patients with stable exertional angina, and 25 patients with chest pain syndrome. In patients with AMI, blood samples were obtained immediately after admission and at 4, 8, 16, 24, and 48 h, and the third, fifth, seventh, and fourteenth day after initiation of reperfusion therapy. Plasma TF levels in patients with AMI on admission were significantly higher than in the chest pain syndrome and stable exertional angina groups (248.0+/-117. 4 vs. 179.5+/-29.2 vs. 189.5+/-29.6 pg/ml, P<0.01). In patients with AMI, the level subsequently decreased after heparin administration and was maintained at significantly lower levels compared to those on admission. Plasma free TFPI levels in patients with AMI on admission were significantly higher than in the chest pain syndrome and stable exertional angina groups [33.5+/-12.4 vs. 26.0+/-7.6 ng/ml (P<0.01) vs. 27.5+/-6.3 ng/ml, P<0.05]. In patients with AMI, it reached the maximum level at 4 h after the administration of heparin, and gradually decreased over the time course. These data indicated that continuous administration of a low dose of heparin was effective in decreasing TF levels without affecting TFPI levels. Our results elucidate one of the mechanisms by which the administration of heparin is beneficial in AMI patients undergoing percutaneous revascularization.

Prediction of stroke by ambulatory blood pressure monitoring versus screening blood pressure measurements in a general population: the Ohasama study

OBJECTIVE

To investigate the association between 24 h, daytime and night-time ambulatory blood pressures and first symptomatic stroke, to compare their predictive powers for stroke with that of casual (screening) blood pressure, and to compare the predictive power for stroke between daytime and night-time blood pressures, in a general population in Ohasama, Japan.

DESIGN

A prospective cohort study.

SUBJECTS AND METHODS

We obtained ambulatory blood pressure on 1,464 subjects aged > or = 40 years without history of symptomatic stroke, then followed-up their stroke-free survival. There were 74 first symptomatic stroke during the follow-up period (mean = 6.4 years). The prognostic significance of blood pressure for stroke risk was examined by a Cox proportional hazards regression model adjusted for possible confounding factors.

RESULTS

The non-parametric and parametric analysis indicated that 24-h, daytime and night-time ambulatory blood pressures were linearly related with stroke risk. The likelihood ratio analysis demonstrated that these ambulatory blood pressures were significantly better related to stroke risk than did screening blood pressure, and that daytime blood pressure better predicted stroke risk than did night-time blood pressure.

CONCLUSIONS

The present study which prospectively investigated the relation between ambulatory blood pressure and first symptomatic stroke risk in a general population demonstrated that (i) ambulatory blood pressure values were linearly related to stroke risk; (ii) ambulatory blood pressures had the stronger predictive power for stroke risk than did screening blood pressure; and (iii) daytime blood pressure better related to stroke risk than did night-time blood pressure.

Japanese individuals do not harbor the T594M mutation but do have the P592S mutation in the C-terminus of the beta-subunit of the epithelial sodium channel: the Ohasama study

OBJECTIVE

To assess the implications of polymorphisms of the amiloride-sensitive epithelial sodium channel in essential hypertension in the Japanese population by determining the incidence of the T594M mutation in the , subunit of the epithelial sodium channel, and by screening the C-terminus of the epithelial sodium channel.

METHODS

Single-strand confirmational polymorphism (SSCP) analysis using two sets of primers which cover the last two-thirds of the last exon coding the B epithelial sodium channel and modification of a specific enzyme restriction site (NlaIII) for the T594M mutation were performed on 803 Japanese subjects. They were randomly selected from the study participants representative of a general population of Ohasama, Japan, who measured their home blood pressure. Polymerase chain reaction (PCR) products presenting a shift in SSCP gel, as well as controls, were directly sequenced by autoanalyser to identify the mutation.

RESULTS

SSCP analysis identified altered migration in five subjects. Four SSCP variants found by sequencing were heterogeneous for the P592S (CCT to TCT) mutation conserving the PY motif, although it was not significantly associated with either home or casual blood pressure values. The resting polymorphism was at codon Thr 594, leading to no change in the amino acid sequence (ACG to ACA). None of the PCR products were modified by NlaIII, indicating the absence of the T594M mutation.

CONCLUSIONS

The epithelial sodium channel variants at the C-terminus are not involved in the common form of essential hypertension in Japanese.