Miki Hosaka

Tohoku University, Japan

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Publications (15)42.24 Total impact

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    ABSTRACT: Abstract Central systolic blood pressure (CSBP) may be a better predictor of cardiovascular risk than clinic brachial (B)SBP. The effects of dose increment from medium dose of angiotensin II receptor blockers (ARBs) to the maximum dose of ARBs (maximum) and changing from medium dose of ARBs to losartan 50 mg/hydrochlorothiazide 12.5 mg combination (combination) were compared in hypertensive patients in whom monotherapy with a medium ARB dose did not achieve goal home SBP (135 mmHg). Four weeks after treatment with a medium ARB dose monotherapy, those whose home SBP level was above 135 mmHg were randomized to receive the maximum ARB dose (n = 101) or the combination (n = 99) once daily for 8 weeks. Both regimens significantly decreased BSBP and CSBP, while a decrease in BSBP and CSBP was greater with combination. The maximum significantly decreased augmentation index (AIx), while the combination did not. The rate of a decrease in reflection to decrease in CSBP was greater in the maximum than in the combination. In the elderly subgroup, the combination more effectively lowered BSBP than the maximum, and only the combination decreased CSBP. However, in the young subgroup, the maximum decreased AIx more than combination, while both regimens lowered CSBP and BSBP to a similar extent. It is explained in part that the maximum may affect pulse wave reflection more predominantly than the combination, especially in young subjects. A weak effect on pulse wave reflection and, thus, on CSBP, of the combination may be overcome by the potent antihypertensive effect of this regimen.
    Clinical and experimental hypertension (New York, N.Y. : 1993). 10/2014;
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    ABSTRACT: Abnormality of circadian blood pressure (BP) variation, i.e. non-dipper, riser, nocturnal hypertension etc, is brought by several pathophysiological conditions especially by secondary hypertension. These pathophysiological conditions are classified into several categories, i.e. disturbance of autonomic nervous system, metabolic disorder, endocrine disorder, disorder of Na and water excretion (e.g. sodium sensitivity), severe target organ damage and ischemia, cardiovascular complications and drug induced hypertension. Each pathophysiological condition which brings disturbance of circadian BP variation is included in several categories, e.g. diabetes mellitus is included in metabolic disorder, autonomic imbalance, sodium sensitivity and endocrine disorder. However, it seems that unified principle of the genesis of disturbance of circadian BP variation in many pathophysiological conditions is autonomic imbalance. Thus, it is concluded that disturbance of circadian BP variation is not purposive biological behavior but the result of autonomic imbalance which looks as if compensatory reaction such as exaggerated Na-water excretion during night in patient with Na-water retention who reveals disturbed circadian BP variation.
    Nihon rinsho. Japanese journal of clinical medicine. 08/2014; 72(8):1429-34.
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    ABSTRACT: In cross-sectional studies, the aldosterone-to-renin ratio (ARR) has been reported to be associated with hypertension under conditions of higher sodium intake. The objective of this prospective study was to investigate the association between ARR and the development of hypertension in community residents stratified by dietary sodium intake.
    American journal of hypertension. 06/2014;
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    ABSTRACT: To determine the association between protein intake and risk of higher-level functional decline in older community-dwelling adults. Prospective. Ohasama Town, Japan. Residents (N = 1,007; mean age 67.4 ± 5.5) free of functional decline at baseline; follow-up was conducted for 7 years. Nutrient and food intakes were determined using a validated 141-item food frequency questionnaire. Participants were divided into quartiles according to intake levels of total, animal, and plant protein. Subscales of the Tokyo Metropolitan Institute of Gerontology Index of Competence subscales were used to assess higher-level functional decline. Logistic regression analysis was used to examine the future risk of higher-level functional decline in relation to protein intake, with lowest protein intake as reference. During the study period, 24.4% of eligible participants reported declines in higher-level functional capacity. After adjustment for putative confounding factors, men in the highest quartile of animal protein intake had significantly lower risk of higher-level functional decline than those in the lowest quartile (odds ratio (OR) = 0.41, 95% confidence interval (CI) = 0.20-0.83; P for trend .01). These associations were not seen in women (OR = 0.76, 95% CI = 0.41-1.34; P for trend .37). No consistent association was observed between plant protein intake and future higher-level functional decline in either sex. Higher protein, particularly animal protein, was associated with lower risk of decline in higher-level functional capacity in older men. Animal protein intake may be a modifiable indicator for early detection and prevention of higher-level functional decline in elderly adults.
    Journal of the American Geriatrics Society 02/2014; · 4.22 Impact Factor
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    ABSTRACT: Abstract Background: An electronic system for salt intake assessment using a 24-h dietary recall method has been developed in Japan. We evaluated the validity of this salt intake system for assessing salt intake. Methods: We prospectively obtained data on estimated salt intake using 24-hour urinary sodium excretion (24-hUNaCl) and salt intake by the salt intake assessment system from 203 consecutive outpatients with essential hypertension (age: 67.8 ± 10.7 years; 53.7% men). Results: Mean values were 9.7 ± 2.9 g/day for 24-hUNaCl and 9.1 ± 2.9 g/day for the salt intake assessment system before corrections. The salt intake estimated by the present system was significantly correlated with 24-hUNaCl (r = 0.66, p < 0.0001). After corrections for habitual use of discretionary seasonings, habitual intake of salty foods, and physical activity, correlation coefficients between salt intake and 24-hUNaCl increased from 0.60 to 0.66 in men <65 years, from 0.80 to 0.81 in men ≥65 years, from 0.64 to 0.75 in women <65 years, and from 0.52 to 0.59 in women ≥65 years. After further correction for regional differences in average salt intake, the correlation coefficient reached 0.72 in all patients. Conclusion: After correction for dietary habits, lifestyle factors, and differences in average salt intake by region, this system may be a useful tool in Japan to encourage salt restriction in the clinical treatment of hypertension and improve public health in terms of salt restriction overall.
    Clinical and Experimental Hypertension 01/2014; · 1.28 Impact Factor
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    ABSTRACT: Numerous factors that affect functional decline have been identified, and personality traits are considered to be an important factor in functional decline risk. The Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG) was developed to measure three higher-level functional capacities, instrumental activities of daily living, intellectual activity, and social roles, in Japanese elderly, which were previously not assessed adequately with existing scales of functional decline. The objective of this study was to explore the effect of personality traits as predictors of higher-level functional decline over a 7-year follow-up in a rural Japanese community. Data on 676 participants (mean 67.1 years) who were free of functional decline and had completed questionnaires at baseline and 7 years later, were analyzed. Demographic characteristics, lifestyle and personality characteristics were obtained from a self-administered questionnaire at baseline. Higher-level functional decline was examined using the subscales of the TMIG at baseline and at a 7-year follow-up examination. Over the 7-year study period, 21.7% of eligible participants reported decline in higher-level functional capacity. After adjustment for putative confounding factors, the traits that were significant predictors of decline in higher-level functional capacity at the 7-year follow-up had higher psychoticism scores [odds ratio (95% confidence interval) 2.12 (1.23-3.66)] and lower extraversion scores [1.89 (1.01-3.56)]. The personality traits of higher psychoticism and lower extraversion were significantly associated with a risk of future functional decline. A better understanding of these personality traits may help identify of at-risk individuals and could help reduce functional decline in older adults.
    The Tohoku Journal of Experimental Medicine 01/2014; 234(3):197-207. · 1.37 Impact Factor
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    ABSTRACT: Abstract Based on ambulatory blood pressure (BP) monitoring, the aldosterone-to-renin ratio (ARR) has been reported to be associated with a diminished nocturnal decline in BP, generally referred to as a "non-dipping" pattern. The objective of this cross-sectional study was to investigate the association between ARR and the non-dipping pattern based on home BP measurements. This study included 177 participants ≥55 years from the general population of Ohasama (mean age: 67.2 years; 74.6% women); no patient was receiving antihypertensive treatment. The median plasma renin activity (PRA), plasma aldosterone concentration (PAC) and ARR were 0.8 ng/mL/h, 8.1 ng/dL and 9.7 ng/dL per ng/mL/h, respectively. Each 1 SD increase in log-transformed (ln) ARR was significantly associated with the prevalence of the non-dipping pattern after adjustments for possible confounding factors including home morning systolic BP (odds ratio, 1.45; p = 0.049). However, no significant associations of PRA or PAC with the non-dipping pattern were observed (p ≥ 0.2). When participants were divided into four groups according to median levels of home morning and night-time systolic BPs, the group with a higher home morning systolic BP (≥128.4 mmHg) with a higher home night-time systolic BP (≥114.4 mmHg) had the greatest ARR levels (ANCOVA p = 0.01). These results support the hypothesis that relative aldosterone excess may be related to a non-dipping pattern in a general population and suggest that a non-dipping pattern can be accurately observed by home BP measurements.
    Clinical and Experimental Hypertension 01/2014; 36(2):108-14. · 1.28 Impact Factor
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    ABSTRACT: Abstract Background/objective: Eplerenone is a highly selective aldosterone blocker, which has the potential to lower blood pressure (BP) in patients with hypertension. The objective of this study was to assess the hypotensive effects of low-dose eplerenone (25 mg) using home BP measurements. We also assessed the time required to reach 95% of the maximum antihypertensive effect (stabilization time) by analyzing exponential decay functions using home BP measurements. Methods: We reviewed the medical records of 83 hypertensive patients who were taking eplerenone 25 mg (age, 68.6 ± 11.8 years; men, 36.1%) in addition to other antihypertensive agents. Home BPs were averaged in each patient for the last 5 days of each observation period. The morning versus evening effect (M/E ratio) and the evening versus morning effect (E/M ratio) were calculated to assess the duration of action of eplerenone. Results: The mean home systolic/diastolic BPs at baseline were 136.8 ± 8.8/77.2 ± 9.3 mmHg, respectively. After 8 weeks of treatment with eplerenone, home systolic/diastolic BP significantly decreased by -7.1 ± 10.1/-2.6 ± 5.0 mmHg (p < 0.0001). The time for stabilization of home systolic and diastolic BPs was 13.7 days (p = 0.006) and 16.5 days (p = 0.001), respectively. When eplerenone was administered in the morning, the M/E ratio was 1.1 ± 0.3. The corresponding E/M ratio for evening administration was 0.9 ± 0.6. Although no nocturia was observed, there was a slight but significant increase in serum potassium levels (p = 0.03). Conclusions: Our data suggest that the combination of eplerenone with other antihypertensive drugs may be a promising therapeutic strategy for the treatment of essential hypertension.
    Clinical and Experimental Hypertension 01/2014; 36(2):83-91. · 1.28 Impact Factor
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    ABSTRACT: Ambulatory blood pressure (BP) is reportedly associated with target organ damage. However, whether ambulatory BP carries prognostic significance for the development of chronic kidney disease (CKD) has not been confirmed. We measured ambulatory BP in 843 participants without CKD at baseline from a general Japanese population and examined the incidence of CKD defined as positive proteinuria or an estimated glomerular filtration rate (eGFR) less than 60 ml/min per 1.73 m at health checks. The association between baseline ambulatory BP and CKD incidence was examined using the Cox proportional hazard regression model adjusted for sex, age, BMI, habitual smoking, habitual alcohol consumption, diabetes mellitus, hypercholesterolemia, a history of cardiovascular disease, antihypertensive medication, eGFR at baseline, the number of follow-up examinations, and the year of the baseline examination. The mean age of the participants averaged 62.9 ± 8.1 years, 71.3% were women and 23.7% were under antihypertensive medication. During a median follow-up of 8.3 years, 220 participants developed CKD events. The adjusted hazard ratios for CKD in a 1-standard deviation increase in daytime and night-time SBP were 1.13 [95% confidence interval (CI) 0.97-1.30] and 1.21 (95% CI 1.04-1.39), respectively. When night-time and daytime BP was mutually adjusted into the same model, only night-time BP persisted as an independent predictor of CKD. Night-time BP is a better predictor of CKD development than daytime BP in the general population. Ambulatory BP measurement is considered useful for evaluating the risk of progression to CKD.
    Journal of Hypertension 09/2013; · 4.22 Impact Factor
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    ABSTRACT: 1. Ambulatory blood pressure (ABP) monitoring (M) provides BP information at many points on any particular day during unrestricted routine daily activities, whereas home blood pressure (HBP) monitoring provides a lot of BP information obtained under fixed times and conditions over a long period of time, thus mean values of HBP provide high reproducibility, and thus an overall superiority compared with ABP. 2. HBP is at least equally or better able than ABP to predict hypertensive target organ damage and prognosis of cardiovascular disease. 3. HBPM allows for ongoing disease monitoring by patients, improves adherence to antihypertensive treatment, and can provide health care providers with timely clinical data and direct and immediate feedback regarding diagnosis and treatment of hypertension. 4. HBPM provides BP information in relation to time, i.e., BP in the morning, in the evening, and at night during sleep, and it is an essential tool for the diagnosis of white-coat and masked hypertension. 5. HBPM yields minimal alerting effects and a placebo effect, and can therefore distinguish small but significant serial changes in BP. It is thus the most practical way to monitor BP in the day-by-day management of hypertension. 6. The superiority of HBPM over ABPM and clinic BPM is apparent from almost all practical and clinical research perspectives. This article is protected by copyright. All rights reserved.
    Clinical and Experimental Pharmacology and Physiology 06/2013; · 2.41 Impact Factor
  • Hypertension 02/2013; · 6.87 Impact Factor
  • Hypertension 12/2012; · 6.87 Impact Factor
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    ABSTRACT: Blood pressure variability based on office measurement predicts outcome in selected patients. We explored whether novel indices of blood pressure variability derived from the self-measured home blood pressure predicted outcome in a general population. We monitored mortality and stroke in 2421 Ohasama residents (Iwate Prefecture, Japan). At enrollment (1988-1995), participants (mean age, 58.6 years; 60.9% women; 27.1% treated) measured their blood pressure at home, using an oscillometric device. In multivariable-adjusted Cox models, we assessed the independent predictive value of the within-subject mean systolic blood pressure (SBP) and corresponding variability as estimated by variability independent of the mean, difference between maximum and minimum blood pressure, and average real variability. Over 12.0 years (median), 412 participants died, 139 of cardiovascular causes, and 223 had a stroke. In models including morning SBP, variability independent of the mean and average real variability (median, 26 readings) predicted total and cardiovascular mortality in all of the participants (P≤0.044); variability independent of the mean predicted cardiovascular mortality in treated (P=0.014) but not in untreated (P=0.23) participants; and morning maximum and minimum blood pressure did not predict any end point (P≥0.085). In models already including evening SBP, only variability independent of the mean predicted cardiovascular mortality in all and in untreated participants (P≤0.046). The R(2) statistics, a measure for the incremental risk explained by adding blood pressure variability to models already including SBP and covariables, ranged from <0.01% to 0.88%. In a general population, new indices of blood pressure variability derived from home blood pressure did not incrementally predict outcome over and beyond mean SBP.
    Hypertension 11/2012; · 6.87 Impact Factor
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    ABSTRACT: This study investigated the association between breastfeeding and both self-measured home blood pressure (HBP) and conventional blood pressure (CBP) in 7-year-old Japanese children. We obtained data pertaining to breastfeeding and blood pressure for 377 mother-offspring pairs from the Tohoku Study of Child Development, which is a prospective birth cohort study. Information on breastfeeding and other factors were obtained from parental questionnaires during the follow-up period. Based on the duration of breastfeeding as a major source of nutrition, mother-offspring pairs were divided into short-term (mean, 5.1 months) and long-term (mean, 11.3 months) breastfeeding groups. At the age of 7 years (84.4±1.8 months), each child's blood pressure was measured. The HBP in the long-term breastfeeding (LBF) group (92.8 mm Hg systolic/55.0 mm Hg diastolic) was significantly lower (P=0.006/0.03) than in the short-term breastfeeding group (94.5/56.3 mm Hg); however, there were no significant differences in the CBP measurements between the short- and LBF groups. Using multiple regression analysis, the duration of breastfeeding (greater than 8 months) was more strongly associated with HBP (P=0.01/0.06) than with CBP (P=0.4/0.8). Furthermore, the adjusted R-squared values for HBP (0.25/0.12) tended to be higher than those for CBP (0.07/0.04). These findings were independent of the birth weight. In conclusion, breastfeeding has a protective effect against elevated blood pressure even in young children, and subtle, but important, differences were precisely detected by self-measurements performed at home.Hypertension Research advance online publication, 6 September 2012; doi:10.1038/hr.2012.128.
    Hypertension Research 09/2012; · 2.79 Impact Factor
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    ABSTRACT: Characteristics of glucose metabolism in subjects with white-coat hypertension (WCHT) have not been fully investigated. The purpose of this study was to determine the relationship between glucose metabolism and WCHT on the basis of blood pressure (BP) at home (HBP) in the general population. Participants were from Ohasama, a rural Japanese community, and included 466 residents (mean age, 61.0 years) who had no history of diabetes mellitus. HBP and oral glucose tolerance test values were measured. Participants were classified into four groups on the basis of their HBP and casual-screening BP (CBP) values: normotension (NT) (HBP<135/85 mm Hg, CBP<140/90 mm Hg); WCHT (HBP<135/85 mm Hg, CBP>/=140/90 mm Hg); masked hypertension (HBP>/=135/85 mm Hg, CBP<140/90 mm Hg); or sustained hypertension (SHT) (HBP>/=135/85 mm Hg, CBP>/=140/90 mm Hg). The relationships between glucose metabolism and BP among the four groups were examined using multivariate analysis adjusted for possible confounding factors. Factors in relation to glucose metabolism, such as fasting glucose level, 2-h postchallenge glucose level and homeostasis model assessment-insulin resistance index, were significantly higher in subjects with WCHT and SHT than in those with NT (all P<0.03). When men and women were analyzed separately, these relationships were more pronounced in women. Our results suggest that dysregulation of glucose metabolism in WCHT might contribute to the increase in the long-term cardiovascular risk among the general population.
    Hypertension Research 09/2010; 33(9):937-43. · 2.79 Impact Factor

Publication Stats

18 Citations
42.24 Total Impact Points

Institutions

  • 2013–2014
    • Tohoku University
      • Department of Life and Pharmaceutical Science
      Japan
  • 2012
    • University of Leuven
      • Division of Hypertension and Cardiovascular
      Louvain, Flanders, Belgium