Self-monitoring of home blood pressure with estimation of daily salt intake using a new electrical device

Effect of salt reduction interventions in lowering blood pressure: A comprehensive systematic review and meta-analysis of controlled clinical trials

BACKGROUND

Excessive salt intake results in hypertension (HTN), which is a major risk factor for cardiovascular disease (CVD). This review and meta-analysis aimed to evaluate the effect of salt reduction interventions on systolic blood pressure (SBP) and diastolic blood pressure (DBP).

METHODS

Studies were identified via systematic searches of the databases, including PubMed, Embase, Scopus, and Web of Science. All the studies examining the effectiveness of salt reduction interventions on blood pressure (BP), regardless of age, sex, and HTN status, were included in the systematic review, and eligible studies were used in the meta-analysis. A random-effect model was applied for quantitative data synthesis.

RESULTS

A total of 50 trials extracted from 40 articles (21 trials on nutrition education,10 on self-help materials,17 on salt substitutes, and 2 on food reformulation) were included in the systematic review. The pooled results of 44 eligible trials showed that salt substitution and nutrition education interventions had significant effects on both SBP (WMD: -7.44 mmHg, P<0.001 and WMD: -2.75 mmHg, P<0.001, respectively), and DBP (WMD: -3.77 mmHg, P<0.001 and WMD: -2.11 mmHg, P<0.001, respectively). Furthermore, using self-help materials led to a significant reduction in SBP among subjects aged 25-60 years (WMD: -2.60 mmHg, P = 0.008); it also decreased both SBP and DBP among those who were hypertensive (WMD: -3.87 mmHg, P = 0.003 and WMD: -2.91 mmHg, P<0.001, respectively).

CONCLUSION

Our results supported that salt substitution and nutrition education are effective nutrition strategies to lower BP. It seems that multi-component approaches could be more effective in improving BP status. However, further trials are required.

A Mobile Health-Based Disease Management Program Improves Blood Pressure in People With Multiple Lifestyle-Related Diseases at Risk of Developing Vascular Disease ― A Retrospective Observational Study ―

Background: The overlap of multiple lifestyle-related diseases increases the risk of vascular diseases. This study investigated the effects of a mobile health (mHealth)-based disease management program on blood pressure and the safety of this program in people with multiple lifestyle-related diseases at risk of developing vascular disease.

Methods and Results: This retrospective observational study was conducted using secondary data collected by PREVENT Inc. People with a full history of hypertension, diabetes, and dyslipidemia and who participated in a 6-month mHealth-based disease management program were included in the study. The primary outcome was blood pressure. Adverse events during the program were investigated to evaluate safety. In total, 125 participants (mean [±SD] age 55.3±6.2 years) were examined. Systolic and diastolic blood pressure were significantly lower after the intervention than at baseline (systolic blood pressure, 128.0±12.3 vs. 131.9±12.7 mmHg [P<0.001]; diastolic blood pressure, 81.2±9.3 vs. 83.6±8.9 mmHg; P=0.003). No serious adverse events occurred during the program.

Conclusions: The present results indicate that the mHealth-based disease management program may reduce blood pressure in people with multiple lifestyle-related diseases at risk of developing vascular disease and that the program is safe. These findings will help shape future health instructions using mHealth-based interventions.

Dietary salt intake in Japan - past, present, and future

Salt reduction is the most important lifestyle modification, especially in Japanese individuals who still consume a significant amount of salt. The Dietary Reference Intakes for Japanese 2020, issued by the Ministry of Health, Labour and Welfare, propose a salt intake goal of <7.5 g/day for men and <6.5 g/day for women. Regarding the goal of salt reduction in hypertensive patients, the hypertension guideline by the Japanese Society of Hypertension 2019 (JSH2019) proposes a goal of <6 g/day. Although the average salt intake in Japan gradually decreased in the early 2000s, the declining trend has not been seen in recent years, and thus, it seems difficult to achieve these target salt intake levels. To overcome this challenge, the JSH announced the 'JSH Tokyo Declaration' and pledged to create a specific action plan to achieve the target salt intake level of <6 g/day. The six strategies to achieve the target salt intake level are as follows: (1) educating citizens on the harms of excessive salt intake and the importance of reducing salt intake; (2) recommending the assessment of the salt intake of individuals or populations and proposing adequate methods to reduce salt intake; (3) promoting salt reduction for children as a part of dietary education at school; (4) promoting salt reduction in takeout food, prepared dishes, canteens, and school lunches; (5) encouraging companies to develop and promote low-salt foods; and (6) encouraging the government to take measures to promote salt reduction. Through these activities, a society with a low salt intake will be expected in the near future.

Salt intake per dish in the Japanese diet: a clue to help establish dietary goals at home

The salt intake of Japanese at home remains high. To aid in salt reduction and encourage a balanced diet, we conducted a cross-sectional study using data from a previous clinical trial in community-dwelling individuals to evaluate major salt sources and relationships among the intake of different dishes in the Japanese diet at home. Dietary records and urinary salt excretion measurements were performed daily for 1 month in seventy-nine participants. The records were classified into six grain dish categories as staple dishes, seven side dish categories and a snack category. Regression analyses were used to estimate (1) salt intake per meal for each category of grain dish, (2) salt intake per dish from each dish category and its contribution to the total salt intake and (3) the influence of grain dish selection on the frequencies of other dishes. Salt intake per meal was approximately 3 g, regardless of grain dish selection. Fish and meat dishes showed the largest contribution to the total salt intake (35 %), followed by vegetable dishes (19 %). The intake of fish or meat and vegetables was promoted by plain rice and reduced by ramen noodles. The intake of dairy products was only promoted by bread, while that of fruits was not influenced by any grain dish category. These results suggest simple strategies to reduce salt intake while maintaining dietary balance, such as eating plain rice more often and using less salt to cook meat/fish and vegetable dishes.

Interventions That Successfully Reduced Adults Salt Intake-A Systematic Review

Background: Adequate sodium intake is important for lowering blood pressure and thus reducing cardiovascular disease risk and other complications. The aim of this review is to identify recent interventions around the world that have been successful in reducing salt intake. Methods: A search in the PubMed, Web of Science and Scopus databases was performed. We include studies published in the last 10 years; randomized trials, pilot intervention without a control arm or experimental study; adult participants; and interventions that successfully reduced salt intake. Study quality was assessed. Results: We included 21 studies, 16 randomized intervention trials and five nonrandomized intervention studies. Eleven interventions described health and nutritional education, seven interventions described nutritional education plus other interventions, and three studies used salt meters to reduce sodium intake. Conclusion: Health and nutritional education, nutritional education plus other interventions and estimates of salt intake showed success in the reduction of salt consumption. There is no evidence that one type of intervention analyzed is more effective than other in reducing salt consumption, so we must analyze each in which individuals or subpopulations will have the intervention performed and use the most suitable approaches to lead to better results.

Development of a Method for Estimating Dietary Salt Intake Using the Overnight Urinary Sodium/Potassium Ratio

Background

There are many patients who need to restrict and assess salt in their diet. However, it is difficult to estimate daily salt intake accurately and easily. Therefore, a method for estimating dietary salt intake using the overnight urinary sodium (Na)/potassium (K) ratio was developed.

Methods

The study involved 43 healthy adults (13 males, 30 females). From 2018 to 2020, subjects consumed a salt-adjusted diet for 11 - 30 days continuously, and overnight urine was collected daily. Using the previous day's salt intake as the objective variable, an equation for estimating the salt intake was developed using a general linear model. To verify the accuracy of the estimating equation, the estimated salt intake of the previous day was calculated using our equation and Tanaka's equation, which is an estimating equation from spot urine widely used in clinical practice and epidemiological studies to estimate dietary salt intake, and they were compared with the actual salt intake.

Results

The results of the analysis showed that model 1 (previous day's salt intake (g) = 3.62 + 0.64 × urinary Na/K ratio + 0.18 × conductivity (mS/cm) - 0.43 × sex (male 0, female 1)) was the optimal model. Then, salt intake was estimated using model 1 and Tanaka's equation, and compared with actual salt intake. The Pearson's product-moment correlation coefficient between the actual and estimated salt intake was r = 0.618 (P < 0.001) and r = 0.573 (P < 0.001) for model 1 estimates and Tanaka's equation estimates, respectively. The percentages of errors within ±30% from the actual salt intake were 64.2% and 58.4% for model 1 and Tanaka's equation, respectively.

Conclusion

An equation for estimating salt intake was developed using the Na/K ratio and conductivity of overnight urine. Although the applicability of this method to hypertensive patients and the elderly has not been studied and needs to be clarified in the future, the estimating equation developed is simple and may be a useful method for daily monitoring of dietary salt intake.

Validation of Self-Monitoring Devices Supporting Sodium Intake Reduction: An Experimental Feeding Study Using Standardized Low-Salt and High-Salt Meals among Healthy Japanese Volunteers

INTRODUCTION

Although several approaches for approximating daily Na intake and the Na/K ratio using casual urine are available, the most useful method remains unclear during daily practice and at home.

METHODS

Twenty-seven participants measured their casual urinary Na/K ratio repeatedly using a Na/K ratio monitor and also measured overnight urine once daily using a monitoring device which delivers on-site feedback to estimate their salt intake under unrestricted, low-salt (LS) (6 g/day), and high-salt (HS) (12 g/day) diets.

RESULTS

The monitoring method utilizing overnight urine to estimate daily Na remained insensitive, resulting in significant overestimation during the LS diet and underestimation during the HS diet periods; estimated salt intake during the LS and HS diet periods plateaued at 7-8 g/day and 9-10 g/day within 3 day; mean estimated salt intake was 11.3 g/day, 7.9 g/day, and 9.8 g/day on the last day of the unrestricted, LS, and HS diets; the coefficient of variation (CV) of the estimated Na intake was 0.23 and 0.17 in the latter half of the low- and high-salt diet periods, respectively. The mean urinary Na/K molar ratio was 5.6, 2.5, and 5.3 on the last day of the unrestricted, LS, and HS diets; the CV of the daily mean Na/K ratio was 0.41 and 0.36 in the latter half of the LS and HS diet periods, respectively. The urinary Na/K ratio during the LS and HS diet periods plateaued within 2 days. The monitoring method based on the daily mean of the casual urinary Na/K ratio reflected the actual change in Na intake, and the estimated value tracked the actual changes in salt intake with smaller difference than the overnight urine estimates when using the estimation coefficient set at 2; estimated salt intake during the LS and HS diet periods plateaued at 5-6 g/day and 10-12 g/day within 2-3 day; mean estimated salt intake was 11.0 g/day, 5.7 g/day, and 10.7 g/day on the last day of the unrestricted, LS, and HS diets, respectively.

DISCUSSION/CONCLUSION

Estimates of daily Na intake derived from overnight urine may remain insensitive during dietary interventions. The urinary Na/K ratio reflects the actual change in Na intake during dietary modification and may serve as a practical marker, particularly during short-term interventions. Conversion from the urinary Na/K ratio to estimated salt intake may be useful, if the coefficient was set appropriate by further investigations.

Exertional sodium loss does not increase immediate salt appetite or dietary sodium intake in athletes

We tested whether salt preference increases immediately after exertion-induced Na⁺ loss in sweat, and whether this may generalise to an increase in habitual dietary Na⁺ intake. For the first aim, trained athletes (n = 20) exercised in 2 ambient temperatures and sweat Na⁺ loss related to immediate salt preference assessed by taste, intake and psychophysical tests. For the second aim, we compared dietary and urinary Na⁺, and salt preference, seasoning and hedonics in the athletes and sedentary men (n = 20). No relationship was found between sodium loss during exercise and immediate preference for salt or psychophysical responses, and no differences in comparison to sedentary men. However, athlete diet had fewer foods (29.4 ± 1.5 vs 37.8 ± 1.9, p < 0.001), less seasoning (19 vs 32. p = 0.011) and more athletes reported dietary limitations (31 vs 11, p < 0.05), although nutrient content did not differ. Together these might suggest athlete adherence to a healthy diet at the expense of variety and flavour and a dissociation between dietary reports and intake. Athletes, more than controls, liked foods rich in energy and K⁺ suggesting compensatory-driven hedonics, although overall their intake did not differ. The findings are consistent with the absence of a salt appetite responding to Na⁺ loss in humans, and specifically that trained athletes do not increase their preference for salt in immediate response to exertion-induced Na⁺ loss and are not at risk for increased dietary Na⁺ compared to sedentary men.

An impact of dietary intervention on blood pressures among diabetic and/or hypertensive patients with high cardiovascular disorders risk in northern Thailand by cluster randomized trial

BACKGROUND

Global sodium intake remains above the recommended levels to control blood pressure (BP). We aimed to evaluate the efficacy of a dietary intervention on BP through salt reduction among community-dwelling participants with high risk of cardiovascular disorders (CVD).

METHODS

This cluster randomized trial (February 2012 to January 2013) included cooking instruction using the pocket salt meter among patients with diabetes and/or hypertension who were treated at health center in Thailand. Based on health centers, 8 clusters of eligible participants were randomly allocated to the 4 intervention and 4 control groups. Dietary intervention was performed at baseline, 1 month, and 3 months in intervention group. In both groups, systolic and diastolic BPs, and estimated 24 hours salt intake based on overnight urine samples were measured at baseline, 6 months, and 12 months.

RESULTS

A total of 753 participants were enrolled (374 in the intervention group and 379 in the control group). In the mixed-effects model, there were significant difference in SBP and estimated salt intake after adjusting covariates at 6 months (adjusted differences between groups [95% CI]; -7.55 [-5.61 to -9.49] mm Hg P < .01; -0.66 [-0.40 to -0.92] g/day P = .03). However, these differences were not observed at 12 months (adjusted differences between groups [95% CI]; -1.83 [0.34 to -4.00] mm Hg P = .48; -0.42 [-0.17 to -0.67] g/day P = .16). There were no differences in DBP in both follow-ups.

CONCLUSIONS

These results may suggest the effectiveness of a visually based dietary intervention targeting salt intake reduction in short term, but the effectiveness discontinued in long term.Clinical trial number: The International Standard Randomized Controlled Trial Number Register (ISRCTN39416277) on January 3, 2012.

Practical and personal education of dietary therapy in hypertensive patients

The guidelines for the management of hypertension by the Japanese Society of Hypertension (JSH2019) defined blood pressure (BP) levels of 130-139/80-89 mmHg as "elevated blood pressure". The JSH2019 also revised the target level of BP control to a lower level. Thus, lifestyle modifications are quite important regardless of the use of antihypertensive drugs. Among the lifestyle modifications, salt reduction is most important, especially among East Asian people, who still consume a significant amount of salt. Since the awareness of salt reduction may not necessarily lead to actual salt reduction, the assessment of individual salt intake is essential when members of the medical staff provide practical guidance regarding salt reduction. The evaluation methods of salt intake are classified as the assessment of dietary contents and the measurement of urinary sodium (Na) excretion. Since highly reliable methods, such as the measurement of 24-h urinary Na excretion, are not convenient in practical clinical settings, the combination of the assessment of dietary contents using questionnaires and the estimation of salt intake using spot urine is recommended as a practical evaluation procedure. Repeated assessment of salt intake and practical guidance from dieticians are useful for long-term adherence to salt reduction. The Japanese Society of Hypertension Salt Reduction Committee began to certify flavorful foods as being low in salt content in 2013. More than 200 products have been certified as of April 2019. The utilization of these products is expected to aid in the salt reduction of hypertensive individuals as well as the Japanese general population.

Combined effects of obesity and objectively-measured daily physical activity on the risk of hypertension in middle-aged Japanese men: A 4-year prospective cohort study

BACKGROUND

The combined effects of physical inactivity and obesity on hypertension have been recognized; however, previous studies evaluated physical activity using questionnaires. We aimed to examine the effects of physical activity, measured using an accelerometer, and obesity on hypertension onset.

METHODS

At baseline, 426 middle-aged Japanese men who were not on antihypertensive medications were included. Physical activity was measured for 7 consecutive days using an accelerometer. Mean daily moderate to vigorous physical activity (MVPA) and step count (SC) were calculated. Low MVPA and low SC were each defined as the first tertile. Obesity was defined as ≥25 kg/m2 of body mass index. The onset of hypertension was defined as receiving antihypertensive agents during the 4-year follow-up. The combined effects of obesity and physical inactivity on hypertension were examined using Cox regression analysis. Potential confounders included age, smoking, alcohol consumption, daily salt intake, dyslipidemia, diabetes mellitus, and systolic and diastolic blood pressures.

RESULTS

Cox regression analysis revealed that both obesity and low MVPA predicted hypertension in patients, independent of confounders (hazard ratio [HR]: 2.64, 95% confidence interval [CI]: 1.08-6.42, p = 0.033), unlike obesity alone (HR: 1.50, 95% CI: 0.50-3.26, p = 0.590). Stratification by obesity and SC revealed similar hypertension risks among the two groups (Obesity with low SC [HR: 2.10, 95% CI 0.88-5.24, p = 0.089]; Obesity without low SC [HR: 1.72, 95% CI 0.93-4.01, p = 0.082]).

CONCLUSIONS

Here, findings suggest that the coexistence of obesity and decreased MVPA may increase the risk of hypertension onset.

A self-monitoring urinary salt excretion level measurement device for educating young women about salt reduction: A parallel randomized trial involving two groups

To prevent and treat hypertension, it is important to restrict salt in one's diet since adolescence. However, an effective salt-reduction education system has yet to be established. Besides accurate evaluation, we believe that the frequent usage of a measurement device may motivate individuals to avoid high salt intake. The present study evaluated the use of a urinary salt excretion measurement device for salt-reduction education in a parallel randomized trial of two groups. The sample comprised 100 university students who provided consent to participate. A survey with 24-hour home urine collection and blood pressure measurement was conducted. Participants in the self-monitoring group measured their own urinary salt excretion level for 4 weeks, using the self-measurement device. Analyses were conducted on 51 participants in the control group and 49 in the self-monitoring group. At baseline, there was no significant difference between the two groups in terms of their characteristics and 24-hour urinary salt excretion levels. After intervention, 24-hour urinary sodium/potassium ratio showed no change in the control group [baseline score: 4.1 ± 1.5; endline score: 4.2 ± 2.0; P = 0.723], but it decreased significantly in the self-monitoring group [baseline score: 4.0 ± 1.7; endline score: 3.5 ± 1.4; P = 0.044]. This change was significant even after adjusting for baseline and endline differences between groups using analysis of covariance (P = 0.045). The self-monitoring urinary salt excretion measurement device improved the 24-hour urinary sodium/potassium ratio. The device is a useful and practical tool for educating young individuals about dietary salt reduction.

Self-monitoring urinary salt excretion device can be used for controlling hypertension for developing countries

Restriction of dietary salt is widely recommended in the management of hypertension, but assessment of individual salt intake has drawn little attention. Monitoring nutritional salt intake through sodium excretion has been popular, because the main route for sodium (Na) excretion is through the urine. Nonetheless, direct measurement of dietary salt intake is time consuming and lacks accuracy. To collect a 24-h urine and measure the content is difficult method for most patients. In this review paper, we would like to explore the usefulness of measuring urinary salt excretion by using a self-monitoring device at home. Measuring daily overnight urine by the self-monitoring device at home will be useful for the management of hypertension suitable for each individual. From the recent increase of processed foods, the term “salt intake” would not accurately be equal to “sodium intake”. Devices measuring urinary sodium excretion have been developed and evaluated on their accuracy and correlation with sodium intake. They must be handy, simple and capable of measuring large populations to be useful for monitoring of daily salt intake and to guide salt restriction as well as the long-term effects by dietary salt intake.

Self-monitoring of urinary salt excretion as a method of salt-reduction education: a parallel, randomized trial involving two groups

OBJECTIVE

The present study aimed to evaluate salt-reduction education using a self-monitoring urinary salt-excretion device.

DESIGN

Parallel, randomized trial involving two groups. The following parameters were checked at baseline and endline of the intervention: salt check sheet, eating behaviour questionnaire, 24 h home urine collection, blood pressure before and after urine collection.

SETTING

The intervention group self-monitored urine salt excretion using a self-measuring device for 4 weeks. In the control group, urine salt excretion was measured, but the individuals were not informed of the result.

SUBJECTS

Seventy-eight individuals (control group, n 36; intervention group, n 42) collected two 24 h urine samples from a target population of 123 local resident volunteers. The samples were then analysed.

RESULTS

There were no differences in clinical background or related parameters between the two groups. The 24 h urinary Na:K ratio showed a significant decrease in the intervention group (-1·1) compared with the control group (-0·0; P=0·033). Blood pressure did not change in either group. The results of the salt check sheet did not change in the control group but were significantly lower in the intervention group. The score of the eating behaviour questionnaire did not change in the control group, but the intervention group showed a significant increase in eating behaviour stage.

CONCLUSIONS

Self-monitoring of urinary salt excretion helps to improve 24 h urinary Na:K, salt check sheet scores and stage of eating behaviour. Thus, usage of self-monitoring tools has an educational potential in salt intake reduction.

Cuffless Blood Pressure Estimation Based on Data-Oriented Continuous Health Monitoring System

Measuring blood pressure continuously helps monitor health and also prevent lifestyle related diseases to extend the expectancy of healthy life. Blood pressure, which is nowadays used for monitoring patient, is one of the most useful indexes for prevention of lifestyle related diseases such as hypertension. However, continuously monitoring the blood pressure is unrealistic because of discomfort caused by the tightening of a cuff belt. We have earlier researched the data-oriented blood pressure estimation without using a cuff. Remarkably, our blood pressure estimation method only uses a photoplethysmograph sensor. Therefore, the application is flexible for sensor locations and measuring situations. In this paper, we describe the implementation of our estimation method, the launch of a cloud system which can collect and manage blood pressure data measured by a wristwatch-type photoplethysmograph sensor, and the construction of our applications to visualize life-log data including the time-series data of blood pressure.

Predictive impact of daily physical activity on new vascular events in patients with mild ischemic stroke

BACKGROUND

Daily physical inactivity is associated with a substantially increased risk of cardiovascular events. However, the target level of daily physical activity remains unclear.

AIM

We aimed to evaluate the impact of physical activity on long-term vascular events in patients with mild ischemic stroke.

METHODS

We designed a single hospital-based prospective observational study and studied 166 ischemic stroke patients (mean age: 63.9 ± 9.2) who had a modified Rankin Scale 0-1. We measured the daily step count as a variable of the daily physical activity after three-months from the stroke onset. Other clinical characteristics including age, body mass index, blood pressure, blood laboratory tests, vascular function and medications were also assessed. The primary outcomes were hospitalization due to stroke recurrence, myocardial infarction, angina pectoris and peripheral artery disease. Survival curves were calculated by a Kaplan-Meier survival analysis, and the hazard ratios for recurrences were determined by univariate and multivariate Cox proportional hazards regression models.

RESULTS

After a median follow-up periods of 1332 days, 34 vascular events (23 stroke recurrences, 11 coronary artery disease) and 7 drop-outs occurred, and the remaining patients were divided into two groups: the without recurrence group (n = 125) and the with recurrence group (n = 34). The daily step count was lower in the nonsurvivor group than in the survivor group. Univariate and multivariate Cox proportional hazards analyses revealed that the daily step counts was independent predictors of new vascular events. A daily step count cutoff value of 6025 steps per day was determined by analyzing the receiver-operating characteristics that showed a sensitivity of 69.4% and a specificity of 79.4%. The Kaplan-Meier survival curves after a log-rank test showed a significantly lower event rate in the more than 6025 steps per day group compared with the less than 6025 steps per day group (P = 0.0002). The positive and negative predictive values of less than 6025 steps were 38.0% and 91.6%, respectively.

CONCLUSION

Our data indicate that daily physical activity evaluated by step counts may be useful for forecasting the prognosis in patients with mild ischemic stroke. Daily step counts of approximately 6000 steps per day may be an initial target level for reducing new vascular events.

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone-induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone-induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040-1124.2010.00046.x, 2010).

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone-induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone-induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040-1124.2010.00046.x, 2010).

Relationship between urinary sodium excretion and pioglitazone-induced edema

To investigate the factors contributing to pioglitazone‐induced edema, we analyzed sodium excretion and several clinical parameters before and after administration of pioglitazone. We analyzed these parameters before and after 8 weeks of administration of pioglitazone to female subjects with type 2 diabetes. When we evaluated whether a significant correlation was found between salt excretion and blood pressure, six patients showed such correlation and 20 patients did not. After 8 weeks of pioglitazone administration, five patients had developed edema, and, surprisingly, such correlation was not found in all five subjects. Salt excretion after administration of pioglitazone was significantly lower in subjects who developed edema and those who showed the correlation, and the hematocrit was significantly lower after administration in the subjects who showed the correlation, but not in the edema group. Pioglitazone‐induced edema would be caused not only by fluid retention, but also by other factors, such as vascular permeability. (J Diabetes Invest, doi: 10.1111/ j.2040‐1124.2010.00046.x, 2010)

Secondary prevention of new vascular events with lifestyle intervention in patients with noncardioembolic mild ischemic stroke: a single-center randomized controlled trial

BACKGROUND

Lifestyle modification is associated with a substantially decreased risk of cardiovascular events. However, the role of lifestyle intervention for secondary prevention in patients with noncardioembolic ischemic stroke is inadequately defined. We assessed the hypothesis that lifestyle intervention can reduce the onset of new vascular events in patients with noncardioembolic mild ischemic stroke.

METHODS

We conducted an observer-blind randomized controlled trial that enrolled 70 patients (48 men, mean age 63.5 years) with acute noncardioembolic mild ischemic stroke. The patients were allocated in equal numbers to a lifestyle intervention group or a control group. We performed lifestyle interventions, which comprised exercise training, salt restriction and nutrition advice for 24 weeks. Then all patients were prospectively followed up for occurrence of the primary endpoints, including hospitalization due to stroke recurrence and the onset of other vascular events. We also evaluated systolic blood pressure (SBP) at the clinic and at home, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), hemoglobin A1c (HbA1c) and high-sensitivity C-reactive protein (hs-CRP) to compare the efficacy of the lifestyle interventions.

RESULTS

This trial was terminated earlier than expected because of the prespecified early stopping rule for efficacy. After the 24-week intervention period, the intervention group showed a significant increase in daily physical activity and a significant decrease in salt intake (physical activity, p = 0.012; salt intake, p < 0.001), with a significant difference between the randomized groups (physical activity, p < 0.001; salt intake, p = 0.018). Similarly, blood pressure was decreased and the HDL-C levels were increased in the intervention group (SBP, p < 0.001; HDL-C, p = 0.018), with significant differences between the randomized groups (SBP, p < 0.001; HDL-C, p = 0.022). In contrast, LDL-C, HbA1c and hs-CRP tended to decrease in the intervention group, but this decrease did not achieve significance. After a median follow-up period of 2.9 years, 12 patients allocated to the control group and 1 patient in the lifestyle intervention group experienced at least 1 vascular event. A sequential plans analysis indicated the superiority of the lifestyle intervention in interim analysis. Kaplan-Meier survival curves after the log-rank test showed a significant prognostic difference between the randomized groups (p = 0.005).

CONCLUSIONS

Lifestyle intervention with appropriate medication is beneficial for reducing the incidence of new vascular events and improving vascular risk factors in patients with noncardioembolic mild ischemic stroke.

The future direction of personalised nutrition: my diet, my phenotype, my genes

Although personalised nutrition is frequently considered in the context of diet-gene interactions, increasingly, personalised nutrition is seen to exist at three levels. The first is personalised dietary advice using Internet-delivered services, which ultimately will become automated and which will also draw on mobile phone technology. The second level of personalised dietary advice will include phenotypic information on anthropometry, physical activity, clinical parameters and biochemical markers of nutritional status. It remains possible that in addition to personalised dietary advice based on phenotypic data, advice at that group or metabotype level may be offered where metabotypes are defined by a common metabolic profile. The third level of personalised nutrition will involve the use of genomic data. While the genomic aspect of personalised nutrition is often considered as its main driver, there are significant challenges to translation of data on SNP and diet into personalised advice. The majority of the published data on SNP and diet emanate from observational studies and as such do not offer any cause-effect associations. To achieve this, purpose-designed dietary intervention studies will be needed with subjects recruited according to their genotype. Extensive research indicates that consumers would welcome personalised dietary advice including dietary advice based on their genotype. Unlike personalised medicine where genotype data are linked to the risk of developing a disease, in personalised nutrition the genetic data relate to the optimal diet for a given genotype to reduce disease risk factors and thus there are few ethical and legal issues in personalised nutrition.

Reducing salt intake for prevention of cardiovascular diseases in high-risk patients by advanced health education intervention (RESIP-CVD study), Northern Thailand: study protocol for a cluster randomized trial

BACKGROUND

Decreasing salt consumption can prevent cardiovascular diseases (CVD). Practically, it is difficult to promote people's awareness of daily salt intake and to change their eating habits in terms of reducing salt intake for better cardiovascular health. Health education programs visualizing daily dietary salt content and intake may promote lifestyle changes in patients at high risk of cardiovascular diseases.

METHODS/DESIGN

This is a cluster randomized trial. A total of 800 high-CVD-risk patients attending diabetes and hypertension clinics at health centers in Muang District, Chiang Rai province, Thailand, will be studied with informed consent. A health center recruiting 100 participants is a cluster, the unit of randomization. Eight clusters will be randomized into intervention and control arms and followed up for 1 year. Within the intervention clusters the following will be undertaken: (1) salt content in the daily diet will be measured and shown to study participants; (2) 24-hour salt intake will be estimated in overnight-collected urine and the results shown to the participants; (3) a dietician will assist small group health education classes in cooking meals with less salt. The primary outcome is blood pressure change at the 1-year follow-up. Secondary outcomes at the 1-year follow-up are estimated 24-hoursalt intake, incidence of CVD events and CVD death. The intention-to-treat analysis will be followed.Blood pressure and estimated 24-hour salt intake will be compared between intervention and control groups at the cluster and individual level at the 1-year follow-up. Clinical CVD events and deaths will be analyzed by time-event analysis. Retinal blood vessel calibers of CVD-risk patients will be assessed cross-sectionally. Behavioral change to reduce salt intake and the influencing factors will be determined by structured equation model (SEM). Multilevel regression analyses will be applied. Finally, the cost effectiveness of the intervention will be analyzed.

DISCUSSION

This study is unique as it will recruit the individuals most vulnerable to CVD morbidity and mortality by applying the general Framingham CVD risk scoring system. Dietary salt reduction will be applied as a prioritized, community level intervention for the prevention of CVD in a developing country.

TRIAL REGISTRATION

ISRCTN39416277.

Effect of salt reduction intervention program using an electronic salt sensor and cellular phone on blood pressure among hypertensive workers

We investigated the effectiveness of a workplace intervention program that utilized self-monitoring of daily salt excretion by an electronic salt sensor and sent personalized e-mail advice via cellular phone. Forty-one hypertensive male workers were assigned to intervention and control groups, then counseled together. Intervention group members were asked to measure daily salt excretion and received e-mail advice. After 4 weeks, a greater decrease of blood pressure (BP) was observed in the intervention group, with significant reductions to daily salt excretion and home BP. The new intervention program is considered useful for BP control among hypertensive workers.

Self-monitoring urinary salt excretion in adults: A novel education program for restricting dietary salt intake

This study aimed to examine the usefulness of the self-monitoring of urinary salt excretion for educating individuals about the risk of excessive dietary salt intake. The subjects were 30 volunteers (15 men and 15 women) not consuming anti-hypertensive medication. The subjects measured urinary salt excretion at home for 4 weeks using a self-monitoring device. Blood pressure (BP), anthropometric variables and nutritional variables (by a dietary-habits questionnaire) were measured before and after the measurement of urinary salt excretion. Statistical analyses were performed, including paired t-tests, Chi-square test, Pearson's product moment correlation coefficient and multiple linear regression analysis. In all subjects, the average urinary salt excretion over 4 weeks was 8.05±1.61 g/day and the range (maximum-minimum value) was 5.58±2.15 g/day. Salt excretion decreased significantly in weeks 3 and 4 (P<0.05 and P<0.01, respectively). Diastolic BP decreased from 77.7±14.3 (at baseline) to 74.3±13.3 after 4 weeks (P<0.05), while systolic BP and anthropometric variables remained unchanged. Nutrition surveys indicated that energy intake was correlated with salt intake both before and after the measurements; changes in both variables during the observation period were correlated (r=0.40, P<0.05). The percentage of subjects who were aware of the restriction in dietary salt intake increased from 47 to 90%. In conclusion, daily monitoring of the amount of urinary salt excretion using a self-monitoring device appears to be an effective educational tool for improving the quality of life of healthy adults.