Effect of soya protein on blood pressure: a meta-analysis of randomised controlled trials

Observational studies have indicated that soya food consumption is inversely associated with blood pressure (BP). Evidence from randomised controlled trials (RCT) on the BP-lowering effects of soya protein intake is inconclusive. We aimed to evaluate the effectiveness of soya protein intake in lowering BP. The PubMed database was searched for published RCT in the English language through to April 2010, which compared a soya protein diet with a control diet. We conducted a random-effects meta-analysis to examine the effects of soya protein on BP. Subgroup and meta-regression analyses were performed to explore possible explanations for heterogeneity among trials. Meta-analyses of twenty-seven RCT showed a mean decrease of 2·21?mmHg (95?% CI -?4·10, -?0·33; P?=?0·021) for systolic BP (SBP) and 1·44?mmHg (95?% CI -?2·56, -?0·31; P?=?0·012) for diastolic BP (DBP), comparing the participants in the soya protein group with those in the control group. Soya protein consumption significantly reduced SBP and DBP in both hypertensive and normotensive subjects, and the reductions were markedly greater in hypertensive subjects. Significant and greater BP reductions were also observed in trials using carbohydrate, but not milk products, as the control diet. Meta-regression analyses further revealed a significantly inverse association between pre-treatment BP and the level of BP reductions. In conclusion, soya protein intake, compared with a control diet, significantly reduces both SBP and DBP, but the BP reductions are related to pre-treatment BP levels of subjects and the type of control diet used as comparison.     

Clinical validation of an automatic device measuring blood pressure in the fingers.

BACKGROUND: To assess the agreement between a new automatic device (FS-20D) using a cuff-oscillometric method to measure arterial blood pressure (BP) in the fingers and a standard mercury sphygmomanometer. METHODS: The blood pressure measurements were taken in a sequential order, in a sample of both normotensive subjects (n. 57) and slight to moderate hypertensive patients (n. 28) without vascular complications. RESULTS: The mean sphygmomanometer-monitor difference was 0.52 +/- 4.57 mmHg for systolic and 0.25 +/- 4.41 mmHg for diastolic values; the agreement limits were: SBP -8.6 divided by 9.6 mmHg, 95% CI: -0.5 divided by 1.5; DBP: -8.6 divided by 9.1 mmHg, 95% CI: -0.7 divided by 1.2. The grade of agreement between the monitor and the sphygmomanometer was "A" (British Hypertension Society) for both systolic and diastolic values (difference of readings < 5 mmHg: 82%; < 10 mmHg: 97% for systolic blood pressure, 98% of diastolic blood pressure). CONCLUSIONS: The monitor was proved to be reliable with a good level of precision and accuracy. The FS-20D monitor may be used in self-monitoring of blood pressure of patients with slight to moderate hypertension.     

气候变化对老年人生理指标的影响初探

目的研究气候变化对老年人群生理指标的影响。方法选择30对老年夫妻,其中高血压患者男性16人,女性14人,于2006年1月—2007年1月进行为期1年的血压、脉搏、体温和体重跟踪监测。气象资料来自国家气象中心,主要指标为日平均气温、日最高气温、日最低气温、日平均气压、日平均风速和日最大风速。结果1年中,非高血压组体重出现低谷的月份为2月,高血压组为9月。两组体温最低出现在2、3月。非高血压组脉搏出现低谷的月份为3、4月,高血压组为9月。两组血压的(收缩压和舒张压)年变化曲线均呈"V"分布,1年中低谷均出现在夏季(7、8、9月),高峰均出现在冬季(12、1、2月),冬季血压均高于夏季(P<0.05)。收缩压、舒张压和日平均气温的相关系数分别为-0.535(P<0.01)和-0.302(P<0.01)。结论人体生理指标存在季节变化和年变化规律,高血压组人群血压随季节变化更为明显。     

The Significance of Duration and Amount of Sodium Reduction Intervention in Normotensive and Hypertensive Individuals: A Meta-Analysis

The purpose of this meta-analysis was to establish the time for achievement of maximal blood pressure (BP) efficacy of a sodium reduction (SR) intervention and the relation between the amount of SR and the BP response in individuals with hypertension and normal BP. Relevant studies were retrieved from a pool of 167 randomized controlled trials (RCTs) published in the period 1973–2010 and integrated in meta-analyses. Fifteen relevant RCTs were included in the maximal efficacy analysis. After initiation of sodium reduction (range: 55–118 mmol/d), there were no significant differences in systolic blood pressure (SBP) or diastolic blood pressure (DBP) between measurements at weeks 1 and 2 (∆SBP: −0.18 mmHg/∆DBP: 0.12 mmHg), weeks 1 and 4 (∆SBP: −0.50 mmHg/∆DBP: 0.35 mmHg), weeks 2 and 4 (∆SBP: −0.20 mmHg/∆DBP: −0.10 mmHg), weeks 2 and 6 (∆SBP: −0.50 mmHg/∆DBP: −0.42 mmHg), and weeks 4 and 6 (∆SBP: 0.39 mmHg/∆DBP: −0.22 mmHg). Eight relevant RCTs were included in the dose-response analysis, which showed that within the established usual range of sodium intake [<248 mmol/d (5700 mg/d)], there was no relation between the amount of SR (range: 136–188 mmol) and BP outcome in normotensive populations [∆SBP: 0.99 mm Hg (95% CI: 2.12, 4.10), P = 0.53; ∆DBP: −0.49 mm Hg (95% CI: −4.0, 3.03), P = 0.79]. In contrast, prehypertensive and hypertensive populations showed a significant dose-response relation (range of sodium reduction: 77–140 mmol/d) [∆SBP: 6.87 mmHg (95% CI: 5.61, 8.12, P < 0.00001); ∆DBP: 3.61 mmHg (95% CI: 2.83, 4.39, P < 0.00001)]. Consequently, the importance of kinetic and dynamic properties of sodium reduction, as well as baseline BP, should probably be considered when establishing a policy of sodium reduction.     

Seasonal changes in ambulatory blood pressure in employees under different indoor temperatures.

OBJECTIVE--The effect of indoor temperature control on summer and winter ambulatory blood pressure levels at work was studied. METHOD--Ambulatory systolic blood pressure (SBP) and diastolic blood pressure (DBP) were monitored once in summer and once in winter in 101 healthy normotensive subjects aged 28-63 years, engaged in similar physical work, from two plants with and three without air conditioning. Subjects were interviewed about health related habits, and measurements of environmental and occupational conditions were obtained. RESULTS--After controlling for possible confounders, mean SBP and DBP during work were significantly higher in winter than in summer (delta SBP = 3.4 mm Hg, P = 0.035; delta DBP = 3.3 mm Hg, P < 0.003). The seasonal change in SBP and DBP showed an independent association with the presence or absence of air conditioning of the industrial plants (SBP: beta = 0.194, P < 0.0001; DBP: beta = 0.054, P = 0.038). The percentage of subjects with increases of more than 10 mm Hg from summer to winter was higher in plants without than with air conditioning. CONCLUSIONS--(1) In normotensive subjects ambulatory working BP varies by season, with higher values in winter. If validated for hypertensive subjects, it may be necessary to tailor drug treatment to these variations. (2) The findings make it clear that drawing valid conclusions from comparisons of BPs between groups requires controlling for several factors, particularly season of the year. (3) Climatic conditions in the industrial plant influence the magnitude of seasonal variations in BP. Work in plants without air conditioning places a considerable added load on the employee's cardiovascular system.     

Low job control is associated with higher diastolic blood pressure in men with mildly elevated blood pressure: the Rosai Karoshi study

Job strain is a risk factor for hypertension, but it is not fully understood if components of job strain, or job demand or job control per se could be related to blood pressure (BP), and if so, whether the relationship differs between normotension and mildly elevated BP. We examined resting BP, and job stress components in 113 Japanese male hospital clerks (38.1 ± 4.4 yr). Subjects were classified into normotensive (NT) (<130/85 mmHg, n=83) and mildly elevated BP (ME) (≥130/85 mmHg) groups. Diastolic BP (DBP) showed a significant interaction between group and job control level (p=0.013). Subjects with low job control demonstrated higher DBP than those with high job control (89.1 ± 2.1 vs. 82.3 ± 2.3 mmHg, p=0.042) in ME group even after adjustments for covariates while DBP did not differ between low and high job control subjects in NT group. Systolic BP (SBP) did not differ between high and low job control subjects in both groups. Neither SBP nor DBP differed between high and low demand groups in either group. Among job strain components, job control may be independently related to BP in Japanese male workers with mildly elevated BP.     

利用交叉滞后通径分析研究血压与肾小球滤过率之间的时间因果关系

目的了解血压(blood pressure,BP)与肾小球滤过率(estimated glomerular filtration rate,eGFR)之间的因果关系。方法于2013年1-8月在辽宁省大洼、彰武和辽阳县农村地区采用多阶段随机整群抽样方法建立了心血管疾病研究队列,并于2015年8月-2016年1月对其中6893名35岁及以上农村居民进行随访调查。采用交叉滞后通径分析模型描述BP与eGFR在高血压和非高血压人群中的因果关系。结果 6893名农村居民(女性占52.3%;平均年龄52.39±10.10岁)的平均随访时间为(28.74±3.47)个月。对于高血压患者,eGFR与收缩压(systolic BP,SBP)相互影响,但eGFR先于SBP发生变化[eGFR→SBP的路径系数ρ1=-0.112,P<0.001;SBP→eGFR的路径系数ρ2=-0.070,P<0.001;ρ1 vs ρ2,P=0.044];eGFR单向影响舒张压(diastolic BP,DBP)。对于非高血压人群,eGFR与SBP相互影响,无先后之分;eGFR与DBP不相互影响。结论农村高血压患者eGFR和血压是相互作用的,且仅存在eGFR升高先于SBP升高。农村非高血压人群eGFR和SBP是相互作用的,且没有先后顺序之分,eGFR和DBP之间无因果关系。     

Improving hypertension control among excessive alcohol drinkers: a randomised controlled trial in France. The WALPA Group.

OBJECTIVES--To improve blood pressure control among hypertensive ( > 140/90 mmHg) excessive alcohol drinkers. DESIGN--Fourteen worksite physicians were randomised onto an intervention group and a control group. The intervention was based on training the worksite physicians and follow up of those hypertensive subjects defined as excessive drinkers. Follow up was based on self monitoring of alcohol consumption by the subject, in view of the results of their gamma glutamyl transferase (GGT) activity determination. SETTING--Fourteen workplaces in France - mainly in the industrial sector. SUBJECTS--Altogether 15 301 subjects were screened by the 14 physicians: 129 of these were included in the study. MAIN OUTCOME MEASURES--This was the difference between the initial systolic blood pressure (SBP) and the SBP one year later (delta BP). Secondary criteria were the difference between the initial and final diastolic blood pressure (delta DBP) and delta BP at two years; antihypertensive treatment; state alcohol consumption (delta AC); delta GGT; and body mass index (delta BMI). RESULTS--The decrease in SBP levels was significantly larger in the intervention group than in the control group: at one year, delta SBP values were -11.9 (15.6) mmHg and -4.6 (13.8) respectively (p < 0.05). This benefit was still observed after two years of follow up (-13.8 (17.4) mmHg v -7.5 (14.2) mmHg (p < 0.05)). No difference was observed in DBP. The percentage of treated subjects did not differ between groups. At one year, delta AC was larger in the intervention group (-2.8 (5.2) U/d) than in the control group (-1.6 (3.4) (p < 0.1)). delta GGT and delta BMI did not differ between the two groups. A weak positive correlation was observed between delta AC and delta SBP (r = 0.16). CONCLUSION--An intervention aimed at the hypertensive excessive drinkers in a working population was found to be effective in reducing SBP on a long term basis (two years). The mechanisms of reduction in alcohol consumption and improved drug compliance cannot be ascertained in this pragmatic study. From a public health point of view, reducing the excess cardiovascular risk among a "hard to reach" population seems feasible with a strategy specifically designed for this high risk group.     

高血压病患者血压昼夜节律异常与心率变异减低的关系

目的：探讨高血压２血压昼夜节律异常与心率变异（ＨＲＶ）减低之间的关系。方法：按ＷＨ标准选择高血压病患者７０例,同期分别作动态血压监测及动态心电图ＨＲＶ分析。结果：血压昼夜节律消失组（Ａ组）较血压昼夜节律正常级（Ｂ组）夜间收缩压（ＳＢＰ）、夜间舒张压（ＤＢＰ）、２４ｈ平均ＳＢＰ、２４ｈ平均ＤＢＰ分别增高１５ｍｍｇ（Ｐ〈０．０１）、６ｍｍＨｇ（Ｐ〈０．０１）、８ｍｍＨｇ（Ｐ〈０．０１）、６ｍｍＨｇ（Ｐ     

Characters available in photoplethysmogram for blood pressure estimation: beyond the pulse transit time

The continuous and noninvasive blood pressure (BP) measurement based on pulse transit time (PTT) doesn’t need cuff and could monitor BP in real time for a long period. However, PTT is just a time index derived from electrocardiogram (ECG) and photoplethysmogram (PPG), while BP-related information within the PPG waveform has seldom been taken into consideration. We hypothesized that PPG waveform feature might be useful for BP estimation. Nine healthy subjects took part in an exercise stress test, including baseline resting, exercise on bicycle ergometry and recovering resting. ECG of lead V5 and PPG from left finger were collected simultaneously, and systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded from a cuff sphygmometer on the right wrist. The correlation coefficients were obtained between BP (SBP, DBP and pulse pressure (PP)) and PPG morphological indices (total 15 indices in terms of waveform amplitude, time span and area ratio). Five PPG indices were correlated with both SBP and PP (absolute value of correlation coefficient |r| > 0.6) and were further tested for the capability to BP estimation, which were: (1) PTT_A, time delay between the R peak of ECG and the foot point of PPG; (2) RSD, time ratio of systole to diastole; (3) RtArea, area ratio of systole to diastole; (4) TmBB, time span of PPG cycle; (5) TmCA, diastolic duration. Comparisons were made between the measured BP and the estimated BP by regression lines and quadratic curve fitting, respectively. As a result, the mean errors of SBP liner fitting with RSD, RtArea, TmBB and TmCA respectively were 5.5, 5.4, 5.2, 5.1 mmHg, which were smaller than that with PTT_A of 5.8 mmHg. And the mean errors of SBP quadratic curve fitting with RSD, RtArea, TmBB and TmCA were all 5.1 mmHg, which were smaller than that with PTT_A of 5.7 mmHg. The mean errors of multiple regression for SBP, PP and DBP was 4.7, 4.7, 3.5 mmHg respectively, which were more accurate than the regression with single PTT_A of 5.8, 5.3, 5.2 mmHg respectively. However, PPG-based SBP and DBP could under estimate cuff pressure by 8 mmHg and over estimate by 10 mmHg respectively, which is a clinically significant error. In conclusion, the combination of time span (PTT, time ratio of systole to diastole, time span of PPG cycle and diastolic duration) and waveform morphology (area ratio of systole to diastole) could improve the performance of PPG-based BP estimation.     

Oral contraceptives: a risk factor for uncontrolled blood pressure among hypertensive women

The objective of the study was to assess the association between systolic and diastolic blood pressure (SBP and DBP) and the use of oral contraceptives (OC) in hypertensive women. In a prospective cross-sectional study, we evaluated 171 women who were referred to the Hypertension Outpatient Clinic of Hospital de Clínicas de Porto Alegre; 66 current users of OC, 26 users of other contraceptive methods and 79 women who were not using contraception. The average of six blood pressure readings was used to establish the usual blood pressure of the participants. Current OC users were compared with users of other methods and with patients not using contraception. Main outcome measures were SBP and DBP among the different groups, and prevalence of uncontrolled hypertension (SBP >or= 140 mmHg and DBP >or= 90 mmHg). DBP was higher in OC users (100.2 +/- 15.9 mmHg) than in patients using other contraceptive methods (93.4 +/- 14.7 mmHg) and not using contraceptives (93.3 +/- 14.4 mmHg, p = 0.016). Women using OC for more than 8 years presented higher age-adjusted blood pressure levels than women using OC for shorter periods. Patients using OC had poor blood pressure control (p for trend = 0.046) and a higher proportion of them presented moderate-severe hypertension. These results were independent of antihypertensive drug use. In a logistic regression model, we found that current OC use was independently and significantly associated with prevalence of uncontrolled hypertension. It is concluded that hypertensive women using OC present a significant increase in DBP and poor blood pressure control, independent of age, weight and antihypertensive drug treatment.     

儿童期血压偏高对成年期高血压的影响研究

目的 本研究旨在探讨儿童期血压偏高对成年期高血压的影响,为成人高血压的早期防控提供科学依据。方法 基于“中国居民健康与营养调查”资料(1991-2011年),纳入儿童期(6~17岁)和成年期(18~38岁)均进行至少1次随访的研究对象。儿童期血压偏高前期定义采用中国儿童青少年血压参考值性别和年龄的第90百分位(P₉₀)至第95百分位(P₉₅),儿童期血压偏高采用≥P₉₅。成年期高血压前期为收缩压/舒张压≥120/80 mmHg且<140/90 mmHg;成年期高血压为收缩压/舒张压≥140/90 mmHg,或有高血压史,或目前正服用降压药物。采用协方差分析和Cox比例风险回归模型分析儿童期血压偏高对成年期高血压前期和高血压的影响,控制混杂因素包括儿童期性别和年龄,成年期的体重指数(BMI)、吸烟和饮酒。结果 本研究共纳入1 984名数据完整的研究对象,中位随访时间为11.7年。基线儿童期共有108人(5.4%)为血压偏高前期,199人(10.0%)为血压偏高。随访成年期共有697人(35.1%)为高血压前期,104人(5.2%)为高血压。协方差分析表明,成年期收缩压和舒张压水平均随着儿童期血压百分位的增加而增加(P_趋势<0.001)。多因素Cox回归分析显示,儿童期血压偏高者成年后为高血压前期的风险增加(HR=1.41,95%CI:1.12~1.77)。儿童期血压偏高者成年后为高血压的风险显著增加(HR=1.73,95%CI:1.01~2.98)。结论 儿童期血压偏高会增加成年期罹患高血压的风险。应该重视儿童青少年血压监测,对血压偏高的高危儿童应及时采取干预措施。     

Blood Pressure at Age 3–24 Years in a Rural Community in Anhui, China

PURPOSE: This community-based study in Anhui, China examined the sex-specific pattern of blood pressure (BP) and its major determinants between age 3 and 24 years.

METHODS: BP, height, weight, and related covariates were obtained from all eligible subjects by consistent methods. A generalized additive model was used to explore independent relations between BP and covariates. The sample for analyses included a total of 14,277 subjects (7244 males and 7033 females).

RESULTS: Systolic blood pressure (SBP)increased linearly with age to an apparent plateau around the age of 15 years in girls and 20 years in boys. Diastolic blood pressure (DBP) essentially paralleled SBP. Until the age of 10, both SBP and DBP were similar in boys and girls; thereafter, values for boys surpassed those for girls with an average difference of 9 mmHg and 4 mmHg for SBP and DBP, respectively, at 20 years of age. This sex difference appeared to persist into early adulthood. The independent relation between BP and each of the three major determinants (age, height, and weight) was nonlinear over the age range studied. Sex-specific regression models with linear terms for age, height and weight were developed for each of four age groups (3–9, 10–14, 15–19, 20–24 years). The 5th, 10th, 90th, and 95th percentiles based on the percentage of predicted values can serve as the cutoffs for low, normal-low, normal-high, and high BP. The predicted values were derived from the above regression models that take into account an individual’s sex, age, height, and weight.

CONCLUSIONS: This analysis provided important basis for classification of hypertension status and subsequent investigation of environmental risk factors in this population.     

Association between serum leptin levels and 24-hour blood pressure in obese women

OBJECTIVE: To assess the relationship between serum leptin and 24-hour blood pressure (BP) in obese women, according to body fat distribution. RESEARCH METHODS AND PROCEDURES: A cross-sectional study was carried out in a population of 70 nondiabetic, normotensive, obese women (40 with android and 30 with gynoid type of obesity) and 20 nonobese healthy women as a control group. All subjects underwent 24-hour ambulatory BP monitoring. Blood samples were collected for serum leptin and plasma insulin measurements. Total cholesterol and high-density lipoprotein cholesterol were also measured. RESULTS: Serum leptin levels were significantly higher in obese subjects than in controls, and they were more elevated in android obese women than in gynoid ones. Leptin levels were positively related to body mass index (BMI), insulin, and waist and hip circumferences in the android group. Among gynoid subjects, leptin levels showed positive associations with BMI and insulin. In women with android obesity, strong positive correlations (p < 0.001) were found between leptin levels and 24-hour systolic BP (SBP), daytime SBP, nighttime SBP, 24-hour diastolic BP (DBP), and daytime DBP. Multiple regression analyses, including age, insulin and leptin concentrations, BMI, and waist and hip circumferences on 24-hour and daytime SBP and DBP, showed that only leptin levels contributed to the variability of BP. CONCLUSIONS: Our study shows that serum leptin levels are directly related to 24-hour BP levels in normotensive women with android fat distribution, independently of BMI.     

Validation of four automatic devices for self-measurement of blood pressure according to the International Protocol of the European Society of Hypertension

Background

Four electronic devices for self-measurement of brachial blood pressure (BP): the Omron M1 Plus, the Omron M6 Comfort, the Spengler KP7500 D, and the Microlife BP A100 Plus, were evaluated in four separate studies according to the International Protocol of the European Society of Hypertension (ESH).

Design

The International Validation Protocol is divided into 2 phases: the first phase is performed on 15 selected subjects (45 pairs of BP measurements); if the device passes this phase, 18 supplementary subjects are included (54 pairs of BP measurements) making a total number of 33 subjects (99 pairs of BP measurements) on which the final validation is performed.

Methods

The same methodology recommended by the ESH protocol was applied for the 4 studies. In each study and for each subject, 4 BP measurements were performed simultaneously by 2 trained observers using mercury sphygmomanometers alternately with 3 measurements by the tested device. The difference between the BP value given by the device and that obtained by the two observers (mean of the two observers) was calculated for each measure. The 99 pairs of BP differences were classified into 3 categories (≤5, ≤10, ≤15 mmHg). The number of differences in each category was compared with the number required by the International Protocol. An individual analysis was then done to determine for each subject the number of comparisons ≤5 mmHg. At least 22 of the 33 subjects should have 2 of their 3 comparisons ≤5 mmHg.

Results

All 4 tested devices passed the first and the second phase of the validation process. The average differences between the device and mercury sphygmomanometer readings were −1.4 ± 5.5 and −0.4 ± 4.8 mmHg for SBP and DBP respectively for the Omron M1 Plus device, −2.1 ± 7.4 and 0.1 ± 4.9 mmHg for SBP and DBP respectively for the Omron M6 Comfort device, −1.4 ± 8.6 and −0.1 ± 3.5 mmHg for SBP and DBP respectively for the Spengler KP7500 D device, and 1.6 ± 4.2 mmHg and 0.54 ± 2.8 mmHg for SBP and DBP respectively for the Microlife BP A100 Plus device. For all devices, readings differing by less than 5, 10, and 15 mmHg for SBP and DBP values fulfill the recommendation criteria of the International Protocol as well as the individual analysis.

Conclusions

Omron M1 Plus (HEM-4011C-E), Omron M6 Comfort (HEM 7000-E), Spengler KP7500 D, and Microlife BP A100 Plus devices fulfilled the validation recommendations of the International Protocol.     

Predictors of the development of hypertension: ten-year follow-up study in a community]

Predictors of the development of hypertension were examined in a 10-year follow-up study of normotensive Japanese adults. Subjects (n = 265), aged 30-69 years at entry, normotensive and with no past history of antihypertensive treatment at entry, were studied in terms of the relationship of various physical, biochemical, dietary, and lifestyle data to the subsequent development of hypertension (defined as systolic blood pressure (SBP) more than 140 mmHg and/or diastolic blood pressure (DBP) more than 90 mmHg and/or starting antihypertensive treatment) with analysis accomplished using univariate and multivariate life table methods. Univariate analyses by the generalized Wilcoxon test showed significantly higher incidence of hypertension in those subjects with SBP 120 mmHg or more (p < 0.001), DBP 75 mmHg or more (p < 0.001), serum glutamate oxaloacetate transaminase (GOT) 20 KU or more (p < 0.001), serum glutamate pyruvate transaminase (GPT) 15 KU or more (p < 0.001), serum gamma-glutamyl transpeptidase (gamma-GTP) 10 IU/l or more (p < 0.001), age 50 or older (p = 0.002), body mass index 22 kg/m2 or more (p = 0.012), and serum creatinine less than 1.2 mg/dl (p = 0.020) than in the other subjects. Multivariate analysis by the Cox proportional hazards model confirmed that relatively higher SBP (p < 0.001), lower serum creatinine (p < 0.001), higher gamma-GTP (p = 0.002), and higher age (p = 0.041) were independent and significant predictors of future hypertension.     

Study of continuous blood pressure estimation based on pulse transit time,heart rate and photoplethysmography-derived hemodynamic covariates

It is widely recognized that pulse transit time (PTT) can track blood pressure (BP) over short periods of time, and hemodynamic covariates such as heart rate, stiffness index may also contribute to BP monitoring. In this paper, we derived a proportional relationship between BP and PPT^?2 and proposed an improved method adopting hemodynamic covariates in addition to PTT for continuous BP estimation. We divided 28 subjects from the Multi-parameter Intelligent Monitoring for Intensive Care database into two groups (with/without cardiovascular diseases) and utilized a machine learning strategy based on regularized linear regression (RLR) to construct BP models with different covariates for corresponding groups. RLR was performed for individuals as the initial calibration, while recursive least square algorithm was employed for the re-calibration. The results showed that errors of BP estimation by our method stayed within the Association of Advancement of Medical Instrumentation limits (??0.98?±?6.00 mmHg @ SBP, 0.02?±?4.98 mmHg @ DBP) when the calibration interval extended to 1200-beat cardiac cycles. In comparison with other two representative studies, Chen’s method kept accurate (0.32?±?6.74 mmHg @ SBP, 0.94?±?5.37 mmHg @ DBP) using a 400-beat calibration interval, while Poon’s failed (??1.97?±?10.59 mmHg @ SBP, 0.70?±?4.10 mmHg @ DBP) when using a 200-beat calibration interval. With additional hemodynamic covariates utilized, our method improved the accuracy of PTT-based BP estimation, decreased the calibration frequency and had the potential for better continuous BP estimation.     

Alcohol consumption, %CDT, GGT and blood pressure change during alcohol treatment

AIMS: Blood pressure (BP) changes in alcohol-dependent individuals during a 12-week alcohol relapse prevention study were examined in light of drinking status and biomarkers of alcohol consumption [carbohydrate-deficient transferrin (%CDT) and gamma-glutamyl transpeptidase (GGT)]. METHODS: Of 160 randomized alcoholic individuals, 120 who had hypertension and in whom daily drinking data was available, at 6 and 12 weeks of treatment were included. The impact of alcohol consumption on change in systolic BP (SBP) and diastolic BP (DBP) was examined. Further analysis determined the relationship between BP and alcohol-use biomarkers. RESULTS: A significant effect of complete abstinence on both SBP (-10 mmHg; P = 0.003) and DBP (-7 mmHg; P = 0.001) when compared to any drinking (SBP and DBP = -1 mmHg) was observed. At week 12, participants with a positive %CDT (> or =2.6) had 7 mmHg greater SBP (P = 0.01) and DBP (P < 0.001) than those with negative %CDT. Participants with positive GGT (> or =50 IU) had 10 mmHg greater SBP (P = 0.12) and 9 mmHg greater DBP (P = 0.03) than those with negative GGT. The percent change in SBP was correlated with percent change in %CDT (P = 0.003) but not GGT (P = ns). The percent change in DBP was correlated with both percent change in %CDT (P < 0.0001) and GGT (P = 0.03). CONCLUSIONS: Abstinence from alcohol significantly decreased the BP and a positive relationship between BP and both alcohol-use biomarkers was illustrated. Since %CDT is more specific than GGT for heavy alcohol consumption, clinicians may monitor the role of alcohol in hypertension using %CDT as a supplemental aid, providing an objective assessment of drinking to influence BP treatment decisions.     

Birth cohort evidence of population influences on blood pressure in the United States, 1887-1994

PURPOSE: Mean blood pressure (BP) has declined in the U.S. for several decades. It is unknown to what extent this decline was due to treatment of persons with recognized high BP or to population-wide influences on BP. Treatment would shift only the highest values lower, whereas, population-wide influences on BP would shift the entire distribution downward. METHODS: We examined changes in the distributions of systolic and diastolic BP (SBP, DBP) across birth cohorts born between 1887 and 1975 in 52,646 individuals examined in the National Health (and Nutrition) Examination Surveys between 1960 and 1994. The BP distributions were estimated as functions of age and birth-year to examine changes between birth cohorts. We postulated that the age-adjusted 10th, 50th and 90th percentiles of SBP and DBP had decreased in more recent versus earlier birth cohorts. RESULTS: The series of birth cohorts exhibited successively lower SBP and DBP at low, middle and high percentiles. In general, the 10th percentile of SBP decreased approximately 1.19 mmHg per decade of birth-year, whereas the 50th percentile decreased 2.40 mmHg per decade, and the 90th percentile decreased 4.62 mmHg per decade. A similar pattern of results was seen for DBP. CONCLUSIONS: The entire distribution of both SBP and DBP shifted downward. The downward shifts at the 50th percentile and below unequivocally demonstrate a strong prevention effect in the U.S. population during the period 1887 through 1975. This epidemiologic analysis indicates that population-wide influences can alter favorably the distribution of BP throughout the whole population.     

Oral arginine improves blood pressure in renal transplant and hemodialysis patients.

BACKGROUND: Hypertension in kidney transplant (KT) patients may result from attenuated whole-body nitric oxide (NO) content and abnormal NO-mediated vasodilation. Increasing NO bioavailability with L-arginine (ARG) could theoretically restore the NO-mediated vasodilatory response and lower blood pressure. METHODS: In a prospective pilot study, 6 normotensive volunteers and 10 KT patients received oral supplements of ARG (9.0 g/d) for 9 days, then 18.0 g/d for 9 more days. Six hemodialysis (HD) and 4 peritoneal dialysis patients received the same dose for 14 days. Five KT patients received 30 mL/d of canola oil (CanO) in addition to ARG. Systolic (SBP) and diastolic (DBP) blood pressure, creatinine clearance (CCr), and serum creatinine (Cr) were measured at baseline, day 9, and day 18. In a subsequent study, 20 hypertensive KT patients with stable but abnormal renal function were randomized in a crossover study to start ARG-only or ARG+CanO supplements for two 2-month periods with an intervening month of no supplementation. SBP, DBP, CCr, and Cr were measured monthly for 7 months. RESULTS: In the pilot study, ARG reduced the SBP in HD patients from 171.5 +/- 7.5 mmHg (baseline) to 142.8 +/- 8.3 mmHg (p = .028). In the crossover study, SBP was reduced from baseline (155.9 +/- 5.0 mmHg), after the first 2 months (143.2 +/- 3.2 mmHg; p = .03) and subsequent 2 months (143.3 +/- 2.5 mmHg; p = .014) of supplementation. DBP was also reduced after supplementation in both studies. CanO had no effect on blood pressure. Renal function did not change. CONCLUSIONS: Oral preparations of ARG (+/-CanO) were well tolerated for up to 60 consecutive days and had favorable effects on SBP and DBP in hypertensive KT and HD patients.