Blood Pressure Categories and Cardiovascular Risk Factors in Japan: The Jichi Medical School (JMS) Cohort Study

Risk of new-onset metabolic syndrome associated with white-coat and masked hypertension: data from a general population

AIM

In the Pressioni Arteriose Monitorate e Loro Associazioni (PAMELA) study, clinical and metabolic variables as well as office, home and ambulatory blood pressure (BP) values were simultaneously measured at baseline and after a 10-year follow-up. The study design allowed us to assess the value of selective and combined elevation of different BP phenotypes in predicting new-onset metabolic syndrome (MetS).

METHODS

The present analysis included 1182 participants without MetS at baseline, as defined by the APT III criteria. On the basis of office, 24-h ambulatory BP and home values, participants were divided into four groups: normal, white-coat hypertension (WCH), masked hypertension and sustained hypertension.

RESULTS

Compared with participants with in-office and out-of-office normal BP, a greater incidence of new-onset age-adjusted and sex-adjusted MetS was observed in WCH (OR = 1.75, CI 1.01-3.04, P = 0.0046), masked hypertension (OR = 2.58, CI 1.26-5.30; P = 0.009) and sustained hypertension (OR = 2.14, CI 1.20-3.79, P = 0.009)) when out-of-office BP was defined by ambulatory criteria. This was not the case when out-of-office BP was defined by home criteria, as only the WCH group showed a greater risk (OR 2.16, CI 1.28-3.63, P = 0.003). Similar findings were obtained for single components of the MetS such as abdominal obesity and hyperglycemia.

CONCLUSION

Our study provides evidence that either isolated or combined BP elevations identified by office/ambulatory measurements, carry an increased risk of new-onset MetS, whereas, only WCH is associated with a greater risk of incident MetS whenever BP phenotypes are identified by office/home measurements. In a clinical perspective, a comprehensive evaluation of BP status based on office/ambulatory measurements may improve diagnosis of new-onset MetS and activate measures for its prevention.

Prevalence and control of high blood pressure in primary care: results from the German Metabolic and Cardiovascular Risk Study (GEMCAS)

Contemporary epidemiological data on blood pressure readings, hypertension prevalence and control in unselected patient populations covering a broad age range are scarce. The aim here is to report the prevalence of high blood pressure and to identify factors associated with blood pressure control in a large German primary care sample. We used data from the German Metabolic and Cardiovascular Risk Study including 35 869 patients aged 18-99 years. High blood pressure was defined as systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg or using antihypertensive therapy. Factors associated with blood pressure control among patients receiving antihypertensive therapy were examined using multiple logistic regressions to estimate odds ratios and 95% confidence intervals. The prevalence of high blood pressure, uncontrolled high blood pressure and untreated high blood pressure was 54.8%, 21.3% and 17.6%, respectively. Age >50 years (1.52; 1.40-1.65), male sex (1.30; 1.20-1.41), elevated waist circumference (1.55; 1.45-1.65), high cholesterol (1.24; 1.16-1.33), high triglycerides (1.11; 1.04-1.19) and concomitant diabetes (1.29; 1.20-1.40) were independently associated with uncontrolled high blood pressure. In a majority of patients we observed hypertension despite treatment for high blood pressures. Studies examining the reasons for treatment failure are highly warranted.

Prevalence of preexisting metabolic syndrome as defined by Japanese original criteria among patients with non-fatal myocardial infarction

OBJECTIVE

We aimed to clarify the prevalence of preexisting Metabolic Syndrome (MetS) defined by the Japanese original criteria among patients with non-fatal myocardial infarction (MI).

METHODS

This is a retrospective cohort study using the computer database obtained by the preliminary health checkup from April 2003 to December 2008. We extracted the subjects with newly developed non-fatal MI from the study population. The newly non-fatal MI was diagnosed by the history of coronary heart disease (CHD) and new appearance of abnormal Q wave on electrocardiograms. MetS was diagnosed by using the Japanese original criteria. If waist circumference was not available, BMI was used alternatively. We evaluated the prevalence of preexisting MetS and other risk factors of CHD among the subjects. We compared the prevalence of preexisting risk factors between MetS group and non-MetS group.

RESULTS

From a study population of 298,455 subjects, 446 subjects with a history of CHD were found. Among the 446, 92 subjects (85 men and 7 women) with abnormal Q wave on electrocardiogram were found. The prevalence of preexisting MetS with non-fatal MI was 19.6% (95% CI; 15.5-23.7%). The prevalence of other preexisting risk factors were 60.0% with smoking history, 55.6% with over-work, 53.3% with stressful life and 36.1% with impaired glucose tolerance. These prevalence rates were not significantly different between MetS group and non-MetS group. Only the prevalence (22.3%) of elevated LDL-cholesterol in the non-MetS group was significantly higher than in the MetS group (14.4%).

CONCLUSION

Preexisting MetS may be able to predict only 20% of future MI. To prevent future myocardial infarction, precaution guidance may be required for people with not only preexisting MetS but also other preexisting risk factors of CHD.

Risk charts illustrating the 10-year risk of myocardial infarction among residents of Japanese rural communities: the JMS Cohort Study

BACKGROUND

Risk charts that depict the absolute risk of myocardial infarction (MI) for each combination of risk factors in individuals are convenient and beneficial tools for primary prevention of ischemic heart disease. Although risk charts have been developed using data from North American and European cardiovascular cohort studies, there is no such chart derived from cardiovascular incidence data obtained from the Japanese population.

METHODS AND RESULTS

We calculated and constructed risk charts that estimate the 10-year absolute risk of MI by using data from the Jichi Medical School (JMS) Cohort Study--a prospective cohort study which followed 12 490 participants in 12 Japanese rural communities for an average of 10.9 years. We identified 92 cases of a clinically-certified MI event. Color-coded risk charts were created by calculating the absolute risk associated with the following conventional cardiovascular risk factors: age, sex, smoking status, diabetes status, systolic blood pressure, and serum total cholesterol.

CONCLUSIONS

In health education and clinical practice, particularly in rural communities, these charts should prove useful in understanding the risks of MI, without the need for cumbersome calculations. In addition, they can be expected to provide benefits by improving existing risk factors in individuals.

Development of new quantitative diagnosis machine to evaluate the baroreflex sensitivity of an artery for patients with hypertension

Text book in all medical school showed that the baroreflex system is one of the most important regulatory systems. When blood pressure increases, heart rate decrease and an artery is dilated with the baroreflex system. By decrease of cardiac output and arterial resistances, blood pressure returns to the normal value. However, there is no diagnostic method, which can measure the sensitivity of a baroreflex system of the artery by the simple methodology. We had challenged invention of the new machine, which could diagnose the sensitivity of the baroreflex system of not only a heart, but also an artery. In this system, the measurement sections are only an electrocardiography (ECG) and peripheral pulse wave. These time series is inputted into a personal computer system, and analyzed quantitatively. Responses of the artery were measured with pulse wave velocity (PWV) calculated from pulse wave transmission time from heart to an artery. In this system, the heart rate change corresponding to the blood-pressure change in time series sequence is observed. Delay time was measured by the cross correlation function. Slope of the blood pressure (BP) change and heart rate (HR) change showed the sensitivity of the baroreflex system of heart. Furthermore, this system can measure the sensitivity of the baroreflex system of an artery. Change of PWV in response to the BP change was observed. We found that significant correlation was observed in the time sequence between BP change and PWV change after delay time calculated from cross correlation. Clinical research was started through allowance of the Ethics Committee. Decreased sensibility in the hypertensive patient's baroreflex system was observed as a result of the clinical research. Furthermore, alteration of the baroreflex sensitivity before and after the drug administration was evaluated. For example, Azelnidipine, Calcium antagonists improved the baroreflex sensitivity of the artery in several cases. This system may be useful f- or the follow up of the hypertensive patients.

Metabolic syndrome and target organ damage: role of blood pressure

A growing body of evidence indicates that the clustering of metabolic and hemodynamic abnormalities characterizing the metabolic syndrome is associated with a prevalence of subclinical damage in a variety of organs, such as left ventricular hypertrophy, thickening or atherosclerotic plaques of carotid arteries, microalbuminuria and deranged renal function. This is clinically relevant since these markers of target organ damage are associated with an increased risk of cardiovascular fatal and nonfatal events. The contribution of the metabolic syndrome to target organ damage in hypertensives is presumably responsible for a substantial increase in cardiovascular fatal and nonfatal events. Thus, target organ damage should be routinely searched for in hypertensives with metabolic syndrome in order to define initial therapeutic strategies and to monitor treatment-induced protection.