Inverse association of des-acyl ghrelin with worksite blood pressure in overweight/obese male workers

Background

Job strain, defined as a combination of high job demands and low job control, has been reported to elevate blood pressure (BP) during work. Meanwhile, a recent experimental study showed that ghrelin blunted the BP response to such mental stress. In the present study, we examined the hypothesis that des-acyl ghrelin may have some beneficial effects on worksite BP through modulating the BP response to work-related mental stress, i.e., job strain.

Methods

Subjects were 34 overweight/obese male day-shift workers (mean age 41.7 ± 6.7 years). No subjects had received any anti-hypertensive medication. A 24-h ambulatory BP monitoring was recorded every 30 min on a regular working day. The average BP was calculated for Work BP, Morning BP, and Home BP. Job strain was assessed using the short version of the Japanese Job Content Questionnaire.

Results

Des-acyl ghrelin showed significant inverse correlations with almost all BPs except Morning SBP, Morning DBP, and Home DBP. In multiple regression analysis, des-acyl ghrelin inversely correlated with Work SBP after adjusting for confounding factors. Des-acyl ghrelin was also negatively associated with BP changes from Sleep to Morning, Sleep to Work, and Sleep to Home.

Conclusions

Des-acyl ghrelin was inversely associated with Worksite BP, suggesting a unique beneficial effect of des-acyl ghrelin on Worksite BP in overweight/obese male day-shift workers.     

Effect of sodium restriction on blood pressure of unstable or uncontrolled hypertensive patients in primary care

BACKGROUND/OBJECTIVES

The aims of the present study are: 1) to quantify sodium consumption of patients with unstable or uncontrolled hypertension, 2) to investigate if reduced sodium intake can lower BP in these patients, and 3), to assess the acceptability and feasibility of this approach.

SUBJECTS/METHODS

This study included 25 adults (age: 50+ years) with frequently elevated BP or patients with uncontrolled, uncomplicated hypertension despite drug treatment in a general practice setting. BP and salt intake (24h urinary excretion and food records) were measured at baseline and after a sodium reduced diet.

RESULTS

Mean (± SD) systolic (SBP) over diastolic (DBP) blood pressure (mmHg) at baseline was 150.7 (± 9.5)/84.149 (± 5.6). Mean urinary sodium excretion was 146 mmol/24h. A reduction of 28 mmol sodium excretion decreased SBP/DBP to 135.5 (± 13.0)/82.5 (± 12.8) (P < 0.001). After one month of no dietary advice, only in 48%, SBP was still ≤140 mmHg.

CONCLUSION

Assessment of sodium intake using food records, 24h urine collections and probing questions to identify use of sodium containing supplements or drugs are essential for tailored advice targeted at sodium intake reduction. The results of the present study indicate that reduced sodium intake can lower BP after 4 weeks in unstable or uncontrolled hypertensive patients.     

Dietary zinc intake is inversely associated with systolic blood pressure in young obese women

Zinc may participate in blood pressure regulation and in the pathogenesis of hypertension. The study examined the relationship between zinc status and blood pressure in obese Korean women. Forty obese women (body mass index (BMI) ≥ 25 kg/m²) aged 19-28 years participated in this study. Zinc intake was estimated from one 24 hour recall and 2-day diet records. Serum and urinary zinc concentrations were determined by atomic absorbance spectrophotometry. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured using an automatic sphygmometer. Metabolic variables, such as waist circumference, triglyceride, high density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin, were also measured. Dietary zinc intake of obese women was averagely 7.5 mg/day. Serum zinc and urinary zinc concentrations were 13.4 µmol/L and 378.7 µg/day, respectively. Averages of SBP and DBP were 119 mmHg and 78 mmHg. Dietary zinc intake was negatively correlated with SBP after adjusting for energy intake (P < 0.05), but serum and urinary zinc concentrations were not found to be correlated with SBP or DBP. Multivariate linear regression analysis showed that dietary zinc intake was inversely associated with SBP in obese women after adjusting for body weight, energy intake and sodium intake (P = 0.0145). The results show that dietary zinc intake may be an independent risk factor of elevated SBP in obese Korean women.     

Indoor air pollution and blood pressure in adult women living in rural China

Background: Almost half of the world’s population uses coal and biomass fuels for domestic energy. Limited evidence suggests that exposure to air pollutants from indoor biomass combustion may be associated with elevated blood pressure (BP).Objective: Our aim was to assess the relationship between air pollution exposure from indoor biomass combustion and BP in women in rural China.Methods: We measured 24-hr personal integrated gravimetric exposure to fine particles < 2.5 µm in aerodynamic diameter (PM_2.5) and systolic BP (SBP) and diastolic BP (DBP) in the winter and summer among 280 women ≥ 25 years of age living in rural households using biomass fuels in Yunnan, China. We investigated the association between PM_2.5 exposure and SBP and DBP using mixed-effects models with random intercepts to account for correlation among repeated measures.Results: Personal average 24-hr exposure to PM_2.5 ranged from 22 to 634 µg/m³ in winter and from 9 to 492 µg/m³ in summer. A 1-log-µg/m³ increase in PM_2.5 exposure was associated with 2.2 mm Hg higher SBP [95% confidence interval (CI), 0.8 to 3.7; p = 0.003] and 0.5 mm Hg higher DBP (95% CI, –0.4 to 1.3; p = 0.31) among all women; estimated effects varied by age group. Among women > 50 years of age, a 1-log-µg/m³ increase in PM_2.5 exposure was associated with 4.1 mm Hg higher SBP (95% CI, 1.5 to 6.6; p = 0.002) and 1.8 mm Hg higher DBP (95% CI, 0.4 to 3.2; p = 0.01). PM_2.5 exposure was positively associated with SBP among younger women, but the association was not statistically significant.Conclusion: PM_2.5 exposure from biomass combustion may be a risk factor for elevated BP and hence for cardiovascular events. Our findings should be corroborated in longitudinal studies.     

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.     

Noise-induced hearing loss and blood pressure

Summary A sample of 188 male and 92 female engineering industry workers was investigated. Pure-tone audiometric measurements were used as an estimator of prolonged noise exposure. Using the air conductance thresholds at frequencies of 3,4 and 6 kHz, subjects were classified into three hearing classes. Their systolic (SBP) and diastolic blood pressure (DBP) was measured.In the older age group (41–64 years), the mean SBP of subjects with moderate hearing loss was 12 mmHg higher among men (n=35) and 18 mmHg higher among women (n=7) than among subjects with normal hearing (n=27). The mean DBP levels of subjects with moderate hearing loss were 5 mmHg and 4 mmHg higher, respectively. However, in the class of severe hearing loss (n=38; only male workers) the mean SBP was only 2 mmHg and the mean DBP only 1 mmHg higher than among subjects with normal hearing. In the younger age group (26–40 years) no differences in either SBP or DBP between the hearing classes were found.     

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.     

Cuffless and Touchless Measurement of Blood Pressure from Ballistocardiogram Based on a Body Weight Scale

Currently, in terms of reducing the infection risk of the COVID-19 virus spreading all over the world, the development of touchless blood pressure (BP) measurement has potential benefits. The pulse transit time (PTT) has a high relation with BP, which can be measured by electrocardiogram (ECG) and photoplethysmogram (PPG). The ballistocardiogram (BCG) reflects the mechanical vibration (or displacement) caused by the heart contraction/relaxation (or heart beating), which can be measured from multiple degrees of the body. The goal of this study is to develop a cuffless and touchless BP-measurement method based on a commercial weight scale combined with a PPG sensor when measuring body weight. The proposed method was that the PTT_BCG-PPGT was extracted from the BCG signal measured by a weight scale, and the PPG signal was measured from the PPG probe placed at the toe. Four PTT models were used to estimate BP. The reference method was the PTT_ECG-PPGF extracted from the ECG signal and PPG signal measured from the PPG probe placed at the finger. The standard BP was measured by an electronic blood pressure monitor. Twenty subjects were recruited in this study. By the proposed method, the root-mean-square error (E_RMS) of estimated systolic blood pressure (SBP) and diastolic blood pressure (DBP) are 6.7 ± 1.60 mmHg and 4.8 ± 1.47 mmHg, respectively. The correlation coefficients, r², of the proposed model for the SBP and DBP are 0.606 ± 0.142 and 0.284 ± 0.166, respectively. The results show that the proposed method can serve for cuffless and touchless BP measurement.     

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。     

Interrelations among smoking habits, casual blood pressure and intraocular pressure in middle and old-aged Japanese residents

Objectives To investigate the association of smoking habits with blood pressure (BP) and intraocular pressure (IOP), and to examine whether the smoking-BP association is related to the IOP level. Methods This study was conducted on the basis of a cross-sectional design using annual health check-up data during one-year between August, 1999 and August, 2000 for 611 middle and old-aged Japanese residents living in Ibaraki prefecture, Japan. Results After adjustment for age, gender, body mass index and alcohol intake score, the proportion of hypertensives, and the mean systolic and diastolic blood pressure (SBP and DBP) of the subjects without antihypertensive medications were the highest (50.4%, 129.6 mmHg and 75.9 mmHg, respectively) in the “smokers of 25 or more cigarettes per day with intraocular pressure (IOP)≥15 mmHg” of six subgroups crossed by three smoking categories (non-smokers, 1 to 24 cigarettes per day, and 25 or more cigarettes per day) and two IOP categories (less than 15 mmHg, and 15mmHg or greater). On the other hand, the adjusted proportion of hypertensives, and the adjusted mean SBP and DBP decreased with increasing smoking category in the individuals with less than 15 mmHg of the IOP (p for trend=0.028 for proportion of hypertensives 0.008 for the SBP, and 0.001 for the DBP, respectively). Conclusions Heavy smoking may be specifically related to ‘high BP accompanied by high IOP’, although the BP may be inversely associated with smoking under the condition without high IOP.     

Randomized Trial on the Effects of Dietary Potassium on Blood Pressure and Serum Potassium Levels in Adults with Chronic Kidney Disease

In the general population, an increased potassium (K) intake lowers blood pressure (BP). The effects of K have not been well-studied in individuals with chronic kidney disease (CKD). This randomized feeding trial with a 2-period crossover design compared the effects of diets containing 100 and 40 mmol K/day on BP in 29 adults with stage 3 CKD and treated or untreated systolic BP (SBP) 120–159 mmHg and diastolic BP (DBP) <100 mmHg. The primary outcome was 24 h ambulatory systolic BP. The higher-versus lower-K diet had no significant effect on 24 h SBP (−2.12 mm Hg; p = 0.16) and DBP (−0.70 mm Hg; p = 0.44). Corresponding differences in clinic BP were −4.21 mm Hg for SBP (p = 0.054) and −0.08 mm Hg for DBP (p = 0.94). On the higher-K diet, mean serum K increased by 0.21 mmol/L (p = 0.003) compared to the lower-K diet; two participants had confirmed hyperkalemia (serum K ≥ 5.5 mmol/L). In conclusion, a higher dietary intake of K did not lower 24 h SBP, while clinic SBP reduction was of borderline statistical significance. Additional trials are warranted to understand the health effects of increased K intake in individuals with CKD.     

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.     

Casein-Derived Lactotripeptides Reduce Systolic and Diastolic Blood Pressure in a Meta-Analysis of Randomised Clinical Trials

There is an urgent need to treat individuals with high blood pressure (BP) with effective dietary strategies. Previous studies suggest a small, but significant decrease in BP after lactotripeptides (LTP) ingestion, although the data are inconsistent. The study aim was to perform a comprehensive meta-analysis of data from all relevant randomised controlled trials (RCT). Medline, Cochrane library, EMBASE and Web of Science were searched until May 2014. Eligibility criteria were RCT that examined the effects of LTP on BP in adults, with systolic BP (SBP) and diastolic BP (DBP) as outcome measures. Thirty RCT met the inclusion criteria, which resulted in 33 sets of data. The pooled treatment effect for SBP was −2.95 mmHg (95% CI: −4.17, −1.73; p < 0.001), and for DBP was −1.51 mmHg (95% CI: −2.21, −0.80; p < 0.001). Sub-group analyses revealed that reduction of BP in Japanese studies was significantly greater, compared with European studies (p = 0.002 for SBP and p < 0.001 for DBP). The 24-h ambulatory BP (AMBP) response to LTP supplementation was statistically non-significant (p = 0.101 for SBP and p = 0.166 for DBP). Both publication bias and “small-study effect” were identified, which shifted the treatment effect towards less significant SBP and non-significant DBP reduction after LTP consumption. LTP may be effective in BP reduction, especially in Japanese individuals; however sub-group, meta-regression analyses and statistically significant publication biases suggest inconsistencies.     

Oat consumption does not affect resting casual and ambulatory 24-h arterial blood pressure in men with high-normal blood pressure to stage I hypertension

The results of epidemiologic studies suggest that increased intake of dietary fiber is associated with lower levels of arterial blood pressure (BP). However, there is little information available addressing the possibility that increased oat consumption may reduce arterial BP in individuals with elevated arterial BP. To test this hypothesis, middle-aged and older men (n = 36; body mass index, 25-35 kg/m(2); aged 50-75 y) with elevated BP (systolic BP 130-159 mmHg and/or diastolic BP 85-99 mmHg) were randomly assigned to consume an additional 14 g/d of dietary fiber in the form of oat (5.5 g beta-glucan, n = 18) or wheat cereals (no beta-glucan, n = 18) for 12 wk. Casual resting arterial BP was measured at baseline and after 4, 8 and 12 wk of intervention. The 24-h ambulatory arterial BP was measured at baseline and after 12 wk of intervention. There were no differences in casual resting or 24-h ambulatory BP at baseline in the two groups. Casual systolic BP (SBP) did not change as a result of the 12-wk intervention in the oat (138 plus minus 2 vs. 135 plus minus 3 mmHg) or wheat (142 plus minus 2 vs. 140 plus minus 3 mmHg) groups, respectively (all P > 0.05). Casual diastolic BP (DBP) also did not change in the oat (89 plus minus 2 vs. 88 plus minus 2 mmHg) or wheat (90 plus minus 2 vs. 91 plus minus 2 mmHg) group during this period (all P > 0.05). Further, 24-h, daytime and nighttime SBP and DBP did not decrease with the intervention. Therefore, the results of the present study suggest that any cardioprotective benefit of regular oat consumption may not be conferred via an arterial BP-lowering effect.     

Blood Pressure and Heart Rate Responses following Dietary Protein Intake in Older Men

Postprandial hypotension (PPH) occurs frequently in older people >65 years old. Protein-rich supplements, particularly whey protein (WP), are increasingly used by older people for various health benefits. We have reported that 70 g WP drinks cause significant, and in some cases marked, falls in blood pressure (BP) in older men. The effects of lower, more widely used, doses (~30 g) on systolic (SBP) and diastolic (DBP) blood pressure and heart rate (HR) are not known. In a randomized order, eight older men (age: 72 ± 1 years; body mass index (BMI): 25 ± 1 kg/m²) after overnight fast ingested a drink containing (i) a non-caloric control (~2 kcal), (ii) 30 g of whey protein (120 kcal; ‘WP30’), or (iii) 70 g of whey protein (280 kcal; ‘WP70’). The BP and HR were measured in this pilot study with an automated device before and at 3-min intervals for 180 min following drink ingestion. Drink condition effects were determined by repeated-measures ANOVA. The SBP decreased after both WP drinks compared to the control (p = 0.016), particularly between 120 and 180 min, with no difference in the effects of WP30 and WP70. The SBP decreased by ≥20 mmHg in more than 50% of people after both WP drinks (WP30: 63%; WP70: 75%) compared to 38% after the control. The maximum fall in the SBP occurred during the third hour, with the nadir occurring latest after WP70. The DBP decreased non-significantly by several mmHg more after the WP drinks than after the control. The maximum HR increases occurred during the third hour, with the greatest increase after WP70. The SBP decreased after both WP drinks compared to the control, with the effects most evident between 120 and 180 min. Accordingly, ingestion of even relatively modest protein loads in older men has the potential to cause PPH.     

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.     

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.     

Temporal Associations between Tri-Ponderal Mass Index and Blood Pressure in Chinese Children: A Cross-Lag Analysis

Background: No longitudinal studies have explored the relationship between tri-ponderal mass index (TMI) and blood pressure (BP) in children. This study is aimed to investigate the temporal associations between TMI and BP among children in China. Methods: A longitudinal study was carried out with Chinese children from 2014 to 2019. Data of the anthropometric examination and blood pressure were collected annually. TMI was calculated by dividing weight by the cube of height. BP was measured using a standard mercury sphygmomanometer. We investigated temporal associations between TMI and BP with a cross-lagged panel model using repeated measure data from 2014 (Wave 1), 2016 (Wave 2), and 2018 (Wave 3). Results: Results of the cross-lagged panel model showed that TMI was associated with subsequent BP. Participants with higher levels of TMI presented higher levels of BP (Wave 1: β = 0.737 for systolic blood pressure (SBP) and β = 0.308 for diastolic blood pressure (DBP), Wave 2: β = 0.422 for SBP and β = 0.165 for DBP, p < 0.01). In addition, children with higher BP could also present higher TMI (Wave 1: β = 0.004 for SBP and β = 0.006 for DBP, Wave 2: β = 0.003 for SBP and β = 0.005 for DBP, p < 0.01), but the cross-lag path coefficient indicated that the influence of TMI on BP was stronger than the influence of BP on TMI. Conclusions: There was a temporal association between TMI and BP in Chinese children. Higher TMI predicted higher subsequent BP rather than the reverse relationship.     

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.