Factors affecting home-measured resting heart rate in the general population: the Ohasama study.

BACKGROUND: We recently demonstrated that a home-measured resting heart rate (HR) can predict cardiovascular disease mortality, and it is possible that the determinants of home HR are different from casual HR. Therefore, clarifying the determinants of home HR should be useful. METHODS: Home HR was obtained using a self-monitored blood pressure (BP) measuring device. The impact of factors including home-measured BP and lifestyle on home HR was examined in 1275 members of the general Japanese population aged > or =40 years. RESULTS: Multivariate linear regression analysis demonstrated that younger age (beta = -0.08, P < or = .01), current smoking (beta = 3.22, P < or = .01), female gender (beta = 2.07, P < or = .01), and sedentary lifestyle (walking for < or =1 h/day) (beta = 2.43, P < or = .01) were determinants of elevated morning home HR. No significant association was observed between home HR and home systolic BP, whereas casual HR was significantly and positively associated with casual systolic BP. The difference between casual and home HR was also significantly and positively associated with the difference between casual and home systolic BP, suggesting that positive association between BP and HR obtained in clinic settings would be a reflection of the so-called white-coat effect. CONCLUSIONS: We observed that, with the exception of BP, most determinants of home HR were consistent with the determinants observed in previous studies using casual HR. These results suggest that reduction of home HR through modification of smoking habit or sedentary lifestyle may have a potential to decrease cardiovascular risk in addition to decreasing in these modifiable risk factor per se.

White-coat hypertension as a risk factor for the development of home hypertension: the Ohasama study.

BACKGROUND: White-coat hypertension is a condition characterized by elevated blood pressure (BP) in medical settings combined with normal ambulatory-recorded BP or self-measured BP at home (home BP). However, it is unknown whether this condition represents a transient state in the development of hypertension outside medical settings. METHODS: We followed up 128 subjects with white-coat hypertension (home BP <135/85 mm Hg and office BP > or = 140/90 mm Hg) for 8 years and compared the risk of progression with home hypertension (home BP > or = 135/85 mm Hg or start of treatment with antihypertensive medication) with 649 sustained normotensive subjects (home BP <135/85 mm Hg and office BP <140/90 mm Hg) using data from population-based home BP measurement projects in Japan. RESULTS: During the 8-year follow-up period, 60 subjects (46.9%) with white-coat hypertension and 144 (22.2%) with sustained normotension progressed to home hypertension. The odds ratio of subjects with white-coat hypertension for progression to home hypertension (adjusted for possible confounding factors) was significantly higher than for subjects with sustained normotension (odds ratio, 2.86; P<.001). This association was observed independent of baseline home BP levels. CONCLUSION: The results from the present 8-year follow-up study demonstrate that white-coat hypertension is a transitional condition to hypertension outside medical settings, suggesting that white-coat hypertension may carry a poor cardiovascular prognosis.

The relationship between body mass index and a plasma lipid peroxidation biomarker in an older, healthy Asian community.

PURPOSE: To examine the association between body mass index (BMI) and the plasma level of a lipid peroxidation biomarker in a large sample of elderly healthy Asian population. This cross-sectional study included 1150 community-dwelling Japanese aged 70 years or older in 2002. METHODS: We measured the lipid peroxidation biomarker 8-iso-prostaglandin F2alpha (8-iso-PGF2alpha) using the ELISA method. We also measured the weight and height and calculated the BMI as weight (kg)/height (m)2. RESULTS: After adjustment for potential confounders, the mean +/- SE plasma 8-iso-PGF(2alpha) level was significantly higher in subjects with higher BMI: 21.1 +/- 0.8 pg/ml in those with BMI of 30.0 or more; 20.5 +/- 0.3 pg/ml in those with BMI between 25.0 and 29.9; 20.0 +/- 0.2 pg/ml in those with BMI between 18.5 and 24.9; and 19.0 +/- 0.7 pg/ml in those with BMI of less than 18.5 (p for trend = 0.011). CONCLUSIONS: Our results demonstrated that in the healthy Asian population, there was a modest but significant relationship between BMI and the plasma lipid peroxidation level.

Prognostic value of home heart rate for cardiovascular mortality in the general population: the Ohasama study.

BACKGROUND: Recently, the advantages of self-measurement of blood pressure (BP) at home have been recognized. The same advantages could also be applicable to resting heart rate (HR) values assessed at home using a device designed for home BP measurement. However, there have been no studies investigating whether home HR values predict the risk of cardiovascular disease mortality. We therefore investigated the usefulness of HR values in predicting cardiovascular mortality using a device that allowed self-measurement of BP and HR at home. METHODS: The association between the home-measured resting HR and the 10-year risk of cardiovascular mortality was examined in 1780 Japanese individuals >/=40 years of age who had no significant arrhythmias. A Cox proportional hazards model that adjusted for major risk factors was used. RESULTS: An increase of 5 beats/min in the morning home HR measurement was associated with a 17% increase in the risk of cardiovascular mortality (95% confidence interval 5% to 30%). This relationship was also statistically significant after adjustment for home BP values. Even when home-measured systolic BP was within the normal range (<135 mm Hg), subjects with HR >/=70 beats/min had a higher risk of cardiovascular mortality (relative hazard 2.16, 95% confidence interval 1.21 to 3.85) than those with normal systolic BP and HR values. CONCLUSIONS: Self-measurement of HR at home, together with self-measurement of BP, is a simple method of providing useful clinical information for assessing cardiovascular risk.

Increased plasma 8-isoprostane levels in hypertensive subjects: the Tsurugaya Project.

To examine the relationship between 8-isoprostane and blood pressure, we measured plasma 8-isoprostane concentration and home blood pressure levels in an elderly Japanese population. Our study population comprised 569 subjects aged 70 years and over who were not receiving antihypertensive medication. On the basis of their blood pressure values, the participants were classified into three groups: normotensive (home blood pressure <135/85 mmHg), hypertensive (home blood pressure 135/85-160/90 mmHg), and severely hypertensive (home blood pressure > or =160/90 mmHg). The mean plasma 8-isoprostane level in the severely hypertensive group (21.1+/-5.2 pg/ml) was significantly higher than that in the normotensive (20.2+/-4.9 pg/ml) or hypertensive (19.7+/-5.1 pg/ml) group, and this result was unchanged when we adjusted for possible confounding factors such as age, sex, use of vitamin A, C or E supplements, smoking status, drinking status, body mass index, use of non-steroidal anti-inflammatory drugs, history of diabetes, hypercholesterolemia, home heart rate and serum creatinine level. Thus, the level of plasma 8-isoprostane appears to be elevated in older subjects with severe hypertension.

Cigarette smoking and mortality in Japan: the Miyagi Cohort Study.

BACKGROUND: We examined the association between smoking and all-cause mortality among Japanese men and women. METHODS: In 1990, 18,945 men and 17,107 women in Miyagi Prefecture in rural northern Japan (40-64 year of age) completed a self-administered questionnaire including items on smoking. Cox regression was used to estimate relative risk (RR) of mortality according to smoking categories, with adjustment for age, education, marital status, past history of diseases, drinking, body mass index, walking, and dietary variables. During 11 years of follow-up, 1,209 men and 499 women had died. RESULTS: Multivariate RRs of all-cause mortality for current smokers as compared with never smokers were 1.71 (95% confidence interval, 1.44-2.03) for men and 1.44 (95% confidence interval, 1.06-1.94) for women. Among men, risk in past smokers who had quit smoking for 15 years or longer was not different from the risk in never smokers (RR, 0.97; 95% confidence interval, 0.68-1.39). Of all deaths, 34% in men and 4% in women were attributable to current or past smoking. CONCLUSIONS: This study indicates that smoking increases the risk of premature death among middle-aged Japanese men and women and that substantial proportion of death, especially for men, is attributable to smoking.

Walking and mortality in Japan: the Miyagi Cohort Study.

BACKGROUND: Although many studies in western populations demonstrated that time spent walking was associated with a reduced risk of all-cause mortality, data on Japanese has been sparse. METHODS: In 1990, 20,004 men and 21,159 women in Miyagi Prefecture in rural northern Japan (40-64 year of age) completed a self-administered questionnaire including a question on time spent walking. Cox regression was used to estimate relative risk (RR) of mortality according to three levels of walking (30 minutes or less, between 30 minutes and one hour, and one hour or more), with adjustment for age, education, marital status, past history of diseases, smoking, drinking, body mass index, and dietary variables. During 11 years of follow-up, 1,879 subjects had died. RESULTS: Time spent walking was inversely associated with risk of all-cause mortality: compared with men and women who walked one hour or more per day, multivariate RR (95% confidence intervals) was 1.06 (0.95-1.19) for subjects who walked between 30 minutes and one hour per day, and 1.16 (1.04-1.29) for subjects who walked 30 minutes or less per day (P for trend=0.007). Shorter duration of walking was associated with increased mortality among men who were never smokers (P for trend=0.081) and past smokers (P for trend=0.026), but not among currently smoking men (P for trend=0.751). We observed similar effect modification for women. CONCLUSIONS: Time spent walking was associated with a reduced risk for all-cause mortality, especially among nonsmoking men and women.

Therapeutic effects of evening administration of guanabenz and clonidine on morning hypertension: evaluation using home-based blood pressure measurements.

OBJECTIVE: To clarify the effects of bedtime administration of the centrally acting alpha(2)-agonists, guanabenz and clonidine, on morning hypertension. METHODS: Patients with morning hypertension were assigned to receive once-daily evening administration of guanabenz (2 mg/day, n = 81; 4 mg/day, n = 2) or clonidine (75 microg/day, n = 40; 150 microg/day, n = 10) for 4 weeks, and the blood pressure (BP)-lowering effects of these drugs in the morning and evening were evaluated by assessing self-monitored BP in the home environment. The subjects were then subdivided into different groups according to their evening BP, and the effects of guanabenz and clonidine on evening BP were evaluated further for each group. In addition, as a substitute for the trough/peak ratio, the evening/morning (E/M) ratio was calculated to assess the duration of action of the two alpha(2)-agonists. RESULTS: Evening dosing with guanabenz or clonidine lowered morning BP significantly. Both drugs decreased evening BP in the subgroup of subjects with a high evening BP, but not in those with a normal evening BP. The individual E/M ratios for guanabenz, but not for clonidine, were significantly greater in those with a high evening BP than in those with a normal evening BP. In the early treatment period, treatment with guanabenz resulted in a higher diastolic E/M ratio in those subjects with a high evening diastolic BP than did treatment with clonidine. CONCLUSION: The results suggest that evening administration of the central alpha(2)-agonists guanabenz and clonidine effectively suppresses the morning BP elevation in treated hypertensive patients.

Heart rate measurement and outcome.

Previous studies on the predictive value of heart rate and heart rate variability for the risk of cardiovascular disease remains controversial. Since heart rate is known to be variable with several physical and mental stresses, the inconclusive nature of previous studies might reflect the difference in accuracy and reproducibility of the heart rate measurement. In the Ohasama study, which has been conducted since 1985 in the northern part of Japan, home measurements and ambulatory monitoring of heart rate as well as blood pressure were examined with special reference to cardiovascular mortality. Heart rate measured at home and averaged for 21 days was shown to be linearly associated with cardiovascular mortality, while heart rate variability (standard deviation of daytime ambulatory heart rate measured every 30 min) inversely correlated with cardiovascular mortality. In conclusion, heart rate and heart rate variability must not be overlooked when evaluating hypertension.

Preparation and dissolution characteristics of griseofulvin solid dispersions with saccharides.

To improve the solubility of poorly water-soluble drugs, we studied physical characteristics of griseofulvin (GF) solid dispersions with saccharides as the dispersion carrier using a roll mixing method. In all carriers tested, roll mixtures of GF and saccharides gradually became amorphous, and the solubility of GF increased. The solubility of GF was higher in the mixtures with higher molecular weight carriers such as corn starch and processed starch. The dissolution of GF was markedly improved by the GF-Britishgum roll mixture. The initial dissolution rate of these mixtures was 170-fold higher than GF alone. The surface tension of carrier aqueous solutions was low in the processed starch with branched sugar chains. The initial dissolution rate of GF in physical mixtures was correlated with the surface tension of carrier aqueous solutions. The stability of the amorphous state of GF at a high humidity was maintained in the mixtures with carriers with a high molecular weight. These results indicated that the solubility of GF was markedly improved in the roll mixtures. It was suggested that the saccharides with a high molecular weight are useful carriers for solid dispersions.