Dietary salt intake and blood pressure in a representative Japanese population: baseline analyses of NIPPON DATA80

Relationship between traditional risk factors for hypertension and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study

Risk factors for hypertension have been emphasized in the Japanese Society of Hypertension Guidelines for the Management of Hypertension. However, large-scale studies on the association of smoking, potassium excretion, and gamma-glutamyl transferase level with BP in the Japanese population are limited. We conducted a cross-sectional study to examine the association between hypertension risk factors and systolic blood pressure in the Tohoku Medical Megabank Community-based Cohort Study (23,446 men and 38,921 women aged ≥20 years). A model adjusted for age, body mass index, smoking status, drinking status, estimated daily salt intake, potassium excretion, (or urinary sodium-to-potassium ratio), gamma-glutamyl transferase, physical activity, education level, status of damage to homes during the Great East Japan Earthquake, and residential areas was used. The average age and systolic blood pressure were 62.5 (10.3) years for men and 59.6 (11.3) years for women, 128.9 (16.7) mmHg for men and 124.7 (17.5) mmHg for women, respectively. Body mass index estimated daily salt intake, urinary sodium-to-potassium ratio and gamma-glutamyl transferase levels were positively associated with systolic blood pressure. Compared with never-drinkers, current drinkers who consumed 23-45 g/day and ≥46.0 g/day had significantly increased systolic blood pressure. Conversely, current smokers (1-10 cigarettes/day and 11-20 cigarettes/day) were inversely associated with systolic blood pressure compared to never-smokers. Overall, systolic blood pressure was associated with gamma-glutamyl transferase and hypertension risk factors, including body mass index, alcohol consumption, estimated daily salt intake, urinary sodium-to-potassium ratio, and potassium excretion. Our findings support the notion that lifestyle modifications should be attempted to prevent hypertension.

Difference in the prevalence of hypertension and its risk factors depending on area-level deprivation in Japan

Objectives

Area-level deprivation is an important factor related to mortality or health behaviors; however, a study investigating differences in hypertension prevalence depending on area-level deprivation has not been conducted in Japan. We investigated differences in the prevalence of hypertension and its risk factors, i.e. obesity, smoking, alcohol consumption, and heavy alcohol drinking depending on area-level deprivation using nationwide health checkups data in 2018.

Results

Area-level deprivation was derived from census data. An analysis of the data by secondary medical areas revealed that the age-standardized proportions of individuals whose systolic blood pressure was ≥ 140 mmHg, those whose diastolic blood pressure was ≥ 90 mmHg, those whose body mass index was ≥ 25 or 30 kg/m², smokers, and heavy alcohol drinkers showed an increasing trend with an increase in the deprivation level. The relative index of inequality, which can be interpreted as the ratio of the age-standardized proportion for the most deprived area compared with that for the least deprived area, was significantly greater than 1 for all proportions, except for the proportion of drinkers in women. Overall, there was a disparity in the prevalence of hypertension and its risk factors depending on area-level deprivation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13104-022-05931-6.

The Lifelong Health Support 10: a Japanese prescription for a long and healthy life

BACKGROUND

Although the age-adjusted incidence and mortality of cancer and cardiovascular disease (CVD) have been decreasing steadily in Japan, both diseases remain major contributors to morbidity and mortality along with the aging society. Herein, we aim to provide a prescription of 10 health tips for long and healthy life named the "Lifelong Health Support 10 (LHS10)."

METHOD

The LHS10 was developed by the preventive medicine specialists at the National Cerebral and Cardiovascular Center in Suita, where it has been used for health guidance to prevent CVD, cancer, and cognitive decline in addition to their major risk factors such as hypertension, diabetes, and obesity. It consisted of the lifestyle modification recommendations of the 2014 Japanese Society of Hypertension guidelines and the 2017 Japan Atherosclerosis Society Guidelines for preventing atherosclerotic CVD. Further, it came in line with other international lifestyle modification guidelines. In this narrative review, we summarized the results of several Japanese epidemiological studies investigating the association between the LHS10 items and the risk of cancer, CVD, and other chronic diseases including dementia, diabetes, and chronic kidney disease.

RESULTS

The LHS10 included avoiding smoking and secondhand smoke exposure, engaging in physical activity, refraining from excessive alcohol drinking, reducing fried foods and sugary soft drinks, cutting salt in food, consuming more vegetables, fruits, fish, soy foods, and fibers, and maintaining proper body weight. All items of the LHS10 were shown to reduce the risk of cancer, CVD, and other chronic diseases.

CONCLUSIONS

The LHS10 can be a helpful tool for health guidance.

High-salt diet suppresses autoimmune demyelination by regulating the blood-brain barrier permeability

Dietary salt intake has been considered an important risk factor for autoimmune diseases like multiple sclerosis (MS). Here we studied the effects of a high-salt diet (HSD) using a spontaneous autoimmune disease mouse model resembling MS. We found that high-salt consumption protects mice from developing the neurological disease by promoting the tightening of the blood–brain barrier and preventing the migration of autoreactive T cells into the CNS. Our results emphasize the multifarious effects of high-salt consumption in autoimmune disease susceptibility.

Sodium chloride, “salt,” is an essential component of daily food and vitally contributes to the body’s homeostasis. However, excessive salt intake has often been held responsible for numerous health risks associated with the cardiovascular system and kidney. Recent reports linked a high-salt diet (HSD) to the exacerbation of artificially induced central nervous system (CNS) autoimmune pathology through changes in microbiota and enhanced T_H17 cell differentiation [M. Kleinewietfeld et al., Nature 496, 518–522 (2013); C. Wu et al., Nature 496, 513–517 (2013); N. Wilck et al., Nature 551, 585–589 (2017)]. However, there is no evidence that dietary salt promotes or worsens a spontaneous autoimmune disease. Here we show that HSD suppresses autoimmune disease development in a mouse model of spontaneous CNS autoimmunity. We found that HSD consumption increased the circulating serum levels of the glucocorticoid hormone corticosterone. Corticosterone enhanced the expression of tight junction molecules on the brain endothelial cells and promoted the tightening of the blood–brain barrier (BBB) thereby controlling the entry of inflammatory T cells into the CNS. Our results demonstrate the multifaceted and potentially beneficial effects of moderately increased salt consumption in CNS autoimmunity.

Nutrition intake among the Japanese elderly: an intergenerational comparison based on national health and nutrition survey scores

Context: The average Japanese lifespan became the longest in the world in 1986. What factors give the Japanese this longevity? Washoku, or the traditional Japanese diet, is respected globally for its nutritionally-balanced and healthy eating habits. This uniquely Japanese way of eating may be one factor that helps extend the Japanese lifespan. Objective: To explain the nutrition intake characteristics of today's Japanese elderly compared with their children's generation and to discuss the association between nutrition intake and various diseases and health issues in the general adult population. Methods: This study compared the characteristics of nutrition status and nutrition intake among today's elderly and their children's generation by using National Health and Nutrition Survey scores. Results: Japanese elderly had high adequacy in all nutrients as well as a high intake of potatoes, pulses, vegetables, fruits, algae, and fish and shellfish compared with their children's generation. Conclusion: Nutrition intake among the Japanese elderly had the characteristics of washoku, but these characteristics were not passed on to the next generation. Extension of the average lifespan and improved health could be achieved by modifying nutrition intake, even after reaching the age of onset of lifestyle- and age-related diseases, typically the 50s.

[Factors Related to Salt-Reduction Cognizance and Salt Intake in Women Aged 40-59 Years: Characteristics of Guardians of Medical University Students]

OBJECTIVES

In our previous study in which we aimed to clarify the factors related to salt intake in women aged 40-59 years, salt intake was found to be not related to salt-reduction cognizance. The aim of this research was to clarify factors related to salt intake in those who were cognizant of the importance of reducing their salt intake.

METHODS

Two hundred and forty-seven female guardians (effective rate, 32.2%) in a medical university, aged 40-59 years old, participated in this study. The participants were divided into three groups according to their salt-reduction cognizance.

RESULTS

There was no significant difference in salt intake between the three groups who were salt-reduction cognizant. Intakes of potassium (mg/1,000 kcal), vegetables, and fruits were higher in those who were cognizant of the importance of reducing their salt intake. The frequencies of consuming stewed foods, miso soup, and vinegared and marinated dishes were also higher. Those who were salt-reduction cognizant were knowledgeable about salt consumption, had experienced making low-salt dishes, used low-sodium seasoning, and made light-tasting dishes by regulating ingredients when cooking. However, when it came to eating, there was no difference in the percentage of those who left most of the broth when eating noodle soups and the frequency with which they added seasoning in terms of salt-reduction cognizance.

CONCLUSION

Salt-reduction cognizant women aged 40-59 years made conscious efforts to use less salt at the time of cooking, but made no efforts when eating, even though they were cognizant of the importance of reducing their salt intake.

Age-Dependent Progression of Renal Dysfunction After Adrenalectomy for Aldosterone-Producing Adenomas in Japan

Context

In patients with aldosterone-producing adenomas (APAs), adrenalectomy causes a rapid decrease in blood pressure and increase in blood potassium levels; however, the effects of these intensive metabolic changes on kidney function with age have not yet been examined in Japan.

Objective

To investigate factors related to the progression of kidney dysfunction after adrenalectomy in different age groups.

Participants

Fifty Japanese patients with APAs and 27,572 health checkup patients as controls were examined.

Main Outcome Measures

We investigated changes in estimated glomerular filtration rate (eGFR) after adrenalectomy and characterized patients who progressed to chronic kidney disease (CKD).

Results

The postoperative cutoff age of CKD is 50 years and age is a unique factor for the progression of CKD after adrenalectomy. Among preoperative patients, CKD was 6% for those <50 years old and 40% for those ≥50 years old, indicating a higher prevalence of CKD with APAs than in control subjects. Median eGFR <50 mL/min/1.73 m² did not significantly change after adrenalectomy but decreased from 67 to 42 mL/min/1.73 m² in those with APAs ≥50 years old. Patients with APAs ≥50 years old who progressed to CKD showed higher preoperative aldosterone/renin ratios, lower potassium and chloride levels, lower body mass index, and a higher incidence of a history of cardiovascular events and KCNJ5 mutation rates.

Conclusion

Age is the most important predictor of the progression of kidney dysfunction after adrenalectomy in Japanese patients with APAs, particularly those with a history of cardiovascular events and positivity for KCNJ5 mutations.

Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012⁻2016 Data

While previous studies have reported the association between food portion size and health outcomes, the association between food seasonings and blood pressure (BP) has not been clarified. This study aimed to investigate the association between the portion sizes of traditional Japanese seasonings and BP. Data on 25,738 Japanese participants (10,154 men and 15,584 women) aged ≥20 years registered in the 2012–2016 National Health and Nutrition Survey (NHNS) were used for this cross-sectional study. The portion sizes of soy sauce or miso were calculated from the reported weight of soy sauce or miso, and the number of dishes. Regression models were used to estimate BP and prevalence of hypertension, and their 95% confidence intervals according to the portion size of soy sauce or miso. We did not observe an association between the portion sizes of soy sauce or miso and BP. A larger portion size of soy sauce or miso was associated with a higher prevalence of hypertension in the crude model among women, but no significant associations were observed in the multivariate model in both sexes. Our findings suggest that the portion sizes of soy sauce or miso are not associated with BP among Japanese adults.

Prevalence and Correlates of Hypertension among Japanese Adults, 1975 to 2010

We investigated the prevalence and factors associated with hypertension, its treatment, and control using individual-level data from 300,249 respondents aged 20 years and older from the Japanese National Health and Nutrition Survey for the period of 1975–2010. We applied multivariate random effects logistic regression to assess associations between the risk factors and the prevalence of hypertension, the proportion of uncontrolled hypertension, and the proportions of respondents seeking treatment and controlling hypertension. The trends in the effect of the birth cohort on uncontrolled hypertension were also examined. Having hypertension was associated with being male, older, obese, drinking alcohol, and working in the primary industry and a higher proportion of middle-aged men than women were found being obese and drinking alcohol. Seeking treatment was associated with being older, obese, drinking alcohol, working in a primary industry and exercising. Controlling hypertension was associated with being younger, underweight and exercising. The proportion of individuals with uncontrolled hypertension declined for cohorts born in later years with a steeper decline for women than men. Raising awareness in the hypertensive population, especially among men, could help further reduce the prevalence of hypertension in Japan.

Sociodemographic Characteristics, Dietary Practices, and Nutritional Status of Adults with Hypertension in a Semi-Rural Community in the Eastern Region of Ghana

Introduction

Hypertension is a major contributor to the global disease burden and mortality. Evidence suggests increasing hypertension prevalence in Ghana but there is limited public awareness and information on the characteristics of those with the disease.

Objective

To describe the baseline characteristics of adults with hypertension who were randomized to receive either hypertension related nutrition education plus hospital-based standard of care or only the standard of care (control group) in Asesewa, a semi-rural community in the Eastern Region of Ghana. Only baseline data were used in the present analysis.

Methods

A cross-sectional baseline survey was completed for 63 adults with confirmed hypertension diagnosis. Data on sociodemographic characteristics and diet were obtained through interviews and participants' body mass index (BMI) was computed. Pearson chi-square statistic was used to assess differences between those with both elevated diastolic blood pressure (DBP) and systolic blood pressure (SBP) and those with only elevated SBP.

Results

Mean ± SD age of participants was 54.5±13.8 years. Approximately 71% of participants had both elevated SBP (>140 mmHg) and DBP (>90 mmHg) while the remaining 29% had only elevated SBP. The median number of times the food groups beneficial to hypertension management were consumed in the preceding week to the interview was 1 for green leafy vegetables, 1 for dairy products, 2 for fruits, and 4 for legumes. The median number of times for consuming harmful food groups was 3 for salted fish and 7 times for fats and oils. Signifcantly more participants in the age group above 50 than the younger participants had elevated SBP (83.3 vs. 16.7:P=0.027) and those with BMI equal to or greater than 25 were more likely to have both elevated SBP and DBP (P=0.047).

Conclusions

Findings from this study have implications for the prevention and management of hypertension in this semi-rural population.

Usefulness of a Short Dietary Propensity Questionnaire in Japan

Aim: There is a growing need for nutritional education for prevention and non-pharmacological treatment of risk factors for cardiovascular diseases (CVD). We compared the results of a short dietary propensity questionnaire (SDPQ) with those from the food frequency and quantity survey (FF Quantity), which had been previously quantitatively assessed by comparison with the 24-hr dietary recall (24hr-DR), to examine the usefulness of the SDPQ. The SDPQ was designed to assess dietary propensities of 12 food/nutrients relevant to CVD risk factors.

Methods: We conducted a dietary survey using the SDPQ on Japanese men and women. After 2–3 weeks, we conducted the FF Quantity survey with the same participants. For each of the 12 food/nutrient categories, the relationships between quintiles of results from the SDPQ and FF Quantity were examined. Results from 79 participants who completed both surveys were used.

Results: Spearman's correlation coefficients (r) were significant for all food/nutrient categories. Good correlations were found with alcohol (r = 0.792), starchy foods (r = 0.566), and milk and dairy products (r = 0.687), for which good correlations between the FF Quantity and 24hr-DR had been observed previously. Moderate correlations were found for vegetables (r = 0.386) and high-salt foods (r = 0.505), although the FF Quantity survey poorly correlated with the 24hr-DR.

Conclusion: The SDPQ may be useful for assessment of dietary propensities for alcohol, starchy foods, and milk and dairy products in Japan.

Depressor effect of the young leaves of Polygonum hydropiper Linn. in high-salt induced hypertensive mice

A novel chymase inhibitor has been reported to have depressor effect in salt-induced hypertension. Therefore, we examined the hypothesis that chymase inhibitory dried young leaves of Polygonum hydropiper (PPH) or young leaves extract of Polygonum hydropiper (PHE) could reduce salt-induced hypertension. In this study, 8-wk old wild-type mice were allocated into three experiments and experiment I included groups, I- normal water drinking, II- high salt (2% NaCl) water (HSW) drinking, and III- HSW plus PPH (500 mg kg^-1, orally) for 12-wk. Blood pressure (BP) and heart rate (HR) were measured at baseline and weekly up to wk-12. In experiment II, mice were given HSW for 12-wk followed by 8-wk treatment with PPH plus HSW (62.5, 125, 250 and 500 mg kg^-1 for groups I, II, III and IV, respectively). BP and HR were measured at baseline and monthly until wk-12, following weekly for 8-wk. Experiment III comprised of four groups of mice for 12-wk HSW and 8-wk treatment with PHE plus HSW (2.5, 5, 10 and 20 mg kg^-1 for groups I-IV, respectively). BP and HR were measured at baseline and monthly up to wk-12, following weekly for 8-wk. Significant reduction in BP and HR were observed in mice treated with PPH (500 mg kg^-1) compared to HSW control. PPH reduced BP and HR dose dependently in hypertensive mice and the higher dose showed maximum reduction. PHE at its maximum dose (20 mg kg^-1) significantly suppressed BP and HR. Over all, we found that the young leaves of Polygonum hydropiper suppressed salt-induced hypertension.

Socioeconomic Status Associated With Urinary Sodium and Potassium Excretion in Japan: NIPPON DATA2010

BACKGROUND

Although socioeconomic status (SES) may affect food and nutrient intakes, few studies have reported on sodium (Na) and potassium (K) intakes among individuals with various SESs in Japan. We investigated associations of SES with Na and K intake levels using urinary specimens in a representative Japanese population.

METHODS

This was a cross-sectional study of 2,560 men and women (the NIPPON DATA2010 cohort) who participated in the National Health and Nutrition Survey Japan in 2010. Casual urine was used to calculate estimated excretion in 24-hour urinary Na (E24hr-Na) and K (E24hr-K). The urinary sodium-to-potassium (Na/K) ratio was calculated from casual urinary electrolyte values. An analysis of covariance was performed to investigate associations of aspects of SES, including equivalent household expenditure (EHE), educational attainment, and job category, with E24hr-Na, E24hr-K, and the Na/K ratio for men and women separately. A stratified analysis was performed on educational attainment and the job category for younger (<65 years) and older (≥65 years) participants.

RESULTS

In men and women, average E24hr-Na was 176.2 mmol/day and 172.3, average E24hr-K was 42.5 and 41.3, and the average Na/K ratio was 3.61 and 3.68, respectively. Lower EHE was associated with a higher Na/K ratio in women and lower E24hr-K in men and women. A shorter education was associated with a higher Na/K ratio in women and younger men, and lower E24hr-K in older men and women.

CONCLUSION

Lower EHE and a shorter education were associated with a lower K intake and higher Na/K ratio estimated from casual urine specimens in Japanese men and women.

Lifestyle Modifications Versus Antihypertensive Medications in Reducing Cardiovascular Events in an Aging Society: A Success Rate-oriented Simulation

Objective It is difficult to compare directly the practical effects of lifestyle modifications and antihypertensive medications on reducing cardiovascular disease (CVD). The purpose of this study was to compare the hypothetical potential of lifestyle modifications with that of antihypertensive medications in reducing CVD in an aging society using a success rate-oriented simulation. Methods We constructed a simulation model for virtual Japanese subpopulations according to sex and age at 10-year intervals from 40 years of age as an example of an aging society. The fractional incidence rate of CVD was calculated as the product of the incidence rate at each systolic blood pressure (SBP) level and the proportion of the SBP frequency distribution in the fractional subpopulations of each SBP. The total incidence rate was calculated by the definite integral of the fractional incidence rate at each SBP level in the sex- and age-specific subpopulations. Results If we consider the effects of lifestyle modifications on metabolic factors and transfer them onto SBP, the reductions in the total incidence rate of CVD were competitive between lifestyle modifications and antihypertensive medications in realistic scenarios. In middle-aged women, the preventive effects of both approaches were limited due to a low incidence rate. In middle-aged men and extremely elderly subjects whose adherence to antihypertensive medications is predicted to be low, lifestyle modifications could be an alternative choice. Conclusion The success rate-oriented simulation suggests that the effectiveness of lifestyle modifications or antihypertensive medications in preventing cardiovascular events largely depends on the baseline incidence rate and sex- and age-specific behavioral factors.

Association of Serum 25-Hydroxyvitamin D and Parathyroid Hormone With Hypertension in Middle-Aged and Older Korean Adults

BACKGROUND

Previous studies have suggested that serum 25-hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) levels are associated with hypertension. However, the associations have yet to be studied in Koreans. This study explored the relationship among serum 25(OH)D, PTH concentrations, and the presence of hypertension in middle-aged and older Korean adults using the most recent nationally representative survey data.

METHODS

A population-based, cross-sectional study was conducted with data collected from 5,260 Korean adults (aged ≥50 years) who participated in the 2010 and 2011 Korean National Health and Nutrition Examination Surveys. Hypertension was defined as a systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or current use of antihypertensive medication.

RESULTS

The prevalence of hypertension significantly increased according to the quartiles of serum PTH levels (P < 0.0001), but not of serum 25(OH)D levels. In multivariable logistic analysis, the adjusted odds ratios (ORs) for hypertension were significantly higher among participants in the highest quartile than among those in the lowest quartile of serum PTH level, after adjusting for potential confounders (OR = 1.26, 95% confidence interval: 1.02-1.56, P = 0.03). The adjusted ORs for hypertension tended to decrease across the quartiles of serum 25(OH)D level, but the associations were not significant.

CONCLUSION

Serum 25(OH)D was not associated with the presence of hypertension, whereas serum PTH was positively associated, suggesting that serum PTH may be an independent risk factor for hypertension in middle-aged and older Korean adults.

Sodium sources in the Japanese diet: difference between generations and sexes

Objective

Globally, the Na consumption of most people exceeds the WHO recommendation. To be effective, salt reduction programmes require assessment of the dietary sources of Na. Due to methodological difficulties however, comprehensive assessments are rare. Here, we identified Na sources in the Japanese diet using a 4 d diet record that was specifically designed for Na source description.

Design

A cross-sectional study.

Subjects

Apparently healthy men (n 196) and women (n 196) aged 20–69 years.

Setting

The subjects were recruited from twenty-three of forty-seven prefectures in Japan.

Results

The proportion of discretionary Na intake in total Na intake was 52·3 % in men and 57·1 % in women, and was significantly lower in younger subjects. The two major food groups contributing to Na intake were seasonings such as salt or soya sauce (61·7 % of total Na intake in men, 62·9 % in women) and fish and shellfish (6·7 % in men, 6·6 % in women). The third major contributor differed between men and women (noodles in men, 4·9 %; bread in women, 5·0 %). Further, the contribution of each food group to total Na intake differed among age groups.

Conclusions

While individual efforts to decrease Na intake remain important, population approaches to reducing Na content in processed foods are already equally important and will assume greater importance in the future even in Japan, an Asian country facing a rapid Westernization in dietary habits.

Lifestyle intervention might easily improve blood pressure in hypertensive men with the C genotype of angiotensin II type 2 receptor gene

BACKGROUND/OBJECTIVES

Recent studies have reported an association of the angiotensin II type 2 receptor (AT2R) 3123Cytosine/Adenine (3123C/A) polymorphism with essential hypertension and cardiovascular diseases. The purpose of the study was to investigate whether the AT2R 3123C/A polymorphism affects blood pressure for free-living hypertensive men during a 5-month intervention period.

SUBJECTS/METHODS

The subjects were free-living hypertensive Japanese men aged 40 to 75 years who agreed to intervention in the period from 2004 to 2011. Detection of the AT2R 3123C/A polymorphism was determined by polymerase chain reaction. The dietary intervention was designed to decrease salt level and to increase potassium level through cooking instructions and self-monitoring of the diet. The exercise session consisted of activities such as stretching, resistance training, and walking. Blood pressure, urinary sodium and potassium excretion, dietary and lifestyle data, and non-fasting venous blood sample were collected at baseline and after the intervention period.

RESULTS

Thirty nine subjects were eligible for participation and the follow-up rate was 97.4%. The C allele proportion was 57.9%. AT2R 3123C/A polymorphism was X-chromosome-linked, therefore we analyzed the C and A genotypes. At baseline, no significant differences were observed between the genotype groups. After the intervention, there were no significant differences in lifestyle habit between the groups. Nevertheless, the estimated salt excretion (g/day) was significantly decreased only in the C genotype (13.0-10.3, P = 0.031). No significant change was observed in systolic blood pressure (SBP) (mmHg) in the A genotype, but a significant decrease was observed in the C genotype (150.0-141.5, P = 0.024).

CONCLUSTIONS

In the C genotype, it might be easy to improve SBP through lifestyle intervention in free-living hypertensive Japanese men, however generalization could not be achieved by the small sample size.

Association of Magnesium Intake with High Blood Pressure in Korean Adults: Korea National Health and Nutrition Examination Survey 2007-2009

Background

Magnesium is known to lower the risk of cardiovascular disease. However, studies on its relationship with hypertension, a single and common cause of various chronic diseases, are limited and their findings are not consistent. The purpose of the present study is to identify the relationship between magnesium intake and high blood pressure (HBP) risk in Koreans.

Methods

This research is a cross-sectional study based on the 2007~2009 Korean National Health and Nutritional Examination Survey data. This study investigated 11,685 adults aged over 20 to examine their general characteristics, anthropometry and blood pressure. Daily magnesium intake was analyzed using the 24-hour dietary recall method. To calculate the odds ratio (OR) of HBP risk (130/85 mmHg or over) according to the quartile of magnesium intake (mg/1000kcal) together with its 95% confidence interval (CI), multivariable logistic regression analysis was performed.

Results

No significant association between dietary magnesium intake and the risk of HBP was found. In obese women, particularly, after adjusting relevant factors, the adjusted odds ratio of HBP prevalence in the highest magnesium intake quartile was 0.40 compared with the lowest magnesium intake quartile (95% CI = 0.25~0.63, P for trend = 0.0014). Women, especially obese women, were found to have a negative relationship of magnesium intake with HBP.

Conclusions

The present results indicate that sufficient magnesium intake could be useful in decreasing the high blood pressure risk of obese women.

The accumulation of brain water-free sodium is associated with ischemic damage independent of the blood pressure in female rats

Estrogen deficiency worsens ischemic stroke outcomes. In ovariectomized (OVX(+)) rats fed a high-salt diet (HSD), an increase in the body Na(+)/water ratio, which characterizes water-free Na(+) accumulation, was associated with detrimental vascular effects independent of the blood pressure (BP). We hypothesized that an increase in brain water-free Na(+) accumulation is associated with ischemic brain damage in OVX(+)/HSD rats. To test our hypothesis we divided female Wistar rats into 4 groups, OVX(+) and OVX(-) rats fed HSD or a normal diet (ND), and subjected them to transient cerebral ischemia. The brain Na(+)/water ratio was increased even in OVX(+)/ND rats and augmented in OVX(+)/HSD rats. The increase in the brain Na(+)/water ratio was positively correlated with expansion of the cortical infarct volume without affecting the BP. Interestingly, OVX(+) was associated with the decreased expression of ATP1α3, a subtype of the Na(+) efflux pump. HSD increased the expression of brain Na(+) influx-related molecules and the mineralocorticoid receptor (MR). The pretreatment of OVX(+)/HSD rats with the MR antagonist eplerenone reduced brain water-free Na(+) accumulation, up-regulated ATP1α3, down-regulated MR, and reduced the cortical infarct volume. Our findings show that the increase in the brain Na(+)/water ratio elicited by estrogen deficiency or HSD is associated with ischemic brain damage BP-independently, suggesting the importance of regulating the accumulation of brain water-free Na(+). The up-regulation of ATP1α3 and the down-regulation of MR may provide a promising therapeutic strategy to attenuate ischemic brain damage in postmenopausal women.

Systolic hypertension: an increasing clinical challenge in Asia

Systolic hypertension, the predominant form of hypertension in patients aged over 50-60 years, is a growing health issue as the Asian population ages. Elevated systolic blood pressure is mainly caused by arterial stiffening, resulting from age-related vascular changes. Elevated systolic pressure increases the risk of cardiovascular disease, mortality and renal function decline, and this risk may increase at lower systolic pressure levels in Asian than Western subjects. Hence, effective systolic pressure lowering is particularly important in Asians yet blood pressure control remains inadequate despite the availability of numerous antihypertensive medications. Reasons for poor blood pressure control include low awareness of hypertension among health-care professionals and patients, under-treatment, and tolerability problems with antihypertensive drugs. Current antihypertensive treatments also lack effects on the underlying vascular pathology of systolic hypertension, so novel drugs that address the pathophysiology of arterial stiffening are needed for optimal management of systolic hypertension and its cardiovascular complications.

The relationship of dietary sodium, potassium, fruits, and vegetables intake with blood pressure among Korean adults aged 40 and older

BACKGROUND/OBJECTIVES

The inverse relationships of combined fruits and vegetables intake with blood pressure have been reported. However, whether there are such relationships with salty vegetables has rarely been investigated in epidemiologic studies. We evaluated the relation of combined and separate intake of fruits, vegetable intakes, and salty vegetables, as well as sodium and potassium, with blood pressure among the middle-aged and elderly populations.

SUBJECTS/METHODS

The present cross-sectional analysis of a prospective cohort baseline survey was performed with 6,283 subjects (2,443 men and 3,840 women) and free of hypertension, diabetes, cardiovascular diseases, and cancer. Dietary data were collected by trained interviewers using food frequency questionnaire.

RESULTS

The significantly inverse linear trend of diastolic blood pressure (DBP) was found in fruits and non-pickled vegetables (81.2 mmHg in the lowest quintile vs 79.0 mmHg in the highest quintile, P for trend = 0.0040) and fruits only (80.9 mmHg in the lowest quintile vs 79.4 mmHg in the highest quintile, P for trend = 0.0430) among men. In contrast, sodium and sodium to potassium ratio were positively related with blood pressure among men (DBP, 78.8 mmHg in the lowest quintile vs 80.6 mmHg in the highest quintile, P for trend = 0.0079 for sodium; DBP, 79.0 mmHg in the lowest quintile vs 80.7 mmHg in the highest quintile, P for trend = 0.0199 and SBP, 123.8 mmHg in the lowest quintile vs 125.9 mmHg in the highest quintile for sodium/potassium). Kimchies consumption was positively related to DBP for men (78.2 mmHg in the lowest quintile vs 80.9 mmHg in the highest quintile for DBP, P for trend = 0.0003). Among women, these relations were not found.

CONCLUSION

Fruits and/or non-pickled vegetables may be inversely, but sodium, sodium to potassium, and Kimchies may be positively related to blood pressure among men.

Healthy aging diets other than the Mediterranean: a focus on the Okinawan diet

The traditional diet in Okinawa is anchored by root vegetables (principally sweet potatoes), green and yellow vegetables, soybean-based foods, and medicinal plants. Marine foods, lean meats, fruit, medicinal garnishes and spices, tea, alcohol are also moderately consumed. Many characteristics of the traditional Okinawan diet are shared with other healthy dietary patterns, including the traditional Mediterranean diet, DASH diet, and Portfolio diet. All these dietary patterns are associated with reduced risk for cardiovascular disease, among other age-associated diseases. Overall, the important shared features of these healthy dietary patterns include: high intake of unrefined carbohydrates, moderate protein intake with emphasis on vegetables/legumes, fish, and lean meats as sources, and a healthy fat profile (higher in mono/polyunsaturated fats, lower in saturated fat; rich in omega-3). The healthy fat intake is likely one mechanism for reducing inflammation, optimizing cholesterol, and other risk factors. Additionally, the lower caloric density of plant-rich diets results in lower caloric intake with concomitant high intake of phytonutrients and antioxidants. Other shared features include low glycemic load, less inflammation and oxidative stress, and potential modulation of aging-related biological pathways. This may reduce risk for chronic age-associated diseases and promote healthy aging and longevity.

Association between dietary behavior and risk of hypertension among Japanese male workers

Dietary behavior can worsen or prevent hypertension. However, data on the association between dietary behavior and the risk of hypertension in Asians are limited. The aim of this study was to determine these associations in Japanese male workers. We conducted a prospective study of 30-71-year-old Japanese male workers in Osaka, Japan, between 2001 and 2011. The study subjects were 3486 normotensive males who were assessed for an average of 4.6 years using an annual survey. We defined hypertension by a systolic blood pressure of ≥140 mm Hg, a diastolic blood pressure of ≥90 mm Hg and/or the use of antihypertensive medications. Dietary behavior questionnaires were included in the annual surveys. For each question on dietary behavior, we calculated the odds ratios (ORs) for the risk of hypertension using logistic regression models. We used subjects who consistently gave affirmative answers in the baseline and end-point surveys as a reference. The number of new cases of hypertension was 846 among 3486 subjects. Compared with subjects who eat meat frequently, subjects who did not eat meat frequently showed a higher risk of hypertension (OR=1.26, 95% confidence interval (CI): 1.00-1.59). Subjects who did not consume dairy products every day showed a higher risk of hypertension (OR=1.39, 95% CI: 1.13-1.71) compared with those who did. Meat and dairy product intake was associated with the prevention of hypertension among Japanese male workers.

Prevalence, risk factors, and management of prehypertension

Prehypertension remains an important public health challenge all over the world and appropriate treatments should be adopted to prehypertensive group in different degree effectively. This review aimed to assess the prevalence of Prehypertension and provide effective evidence of the benefits of treating prehypertensive patients. The reasonable evaluation and appropriate intervention of prehypertensive remain need further study.

Serum 25-hydroxyvitamin D and parathyroid hormone levels in relation to blood pressure in a cross-sectional study in older Chinese men

Vitamin D status, parathyroid hormone (PTH) level and their associations with blood pressure in Chinese population are unknown. This study examined these associations in older Chinese men. Blood pressure, serum 25-hydroxyvitamin D (25OHD) and PTH was measured in 939 community-dwelling Chinese men aged 65 years and older. Linear regression analyses were performed with adjustments for age, body mass index, education, season of measurement, medication use, self-reported history of stroke and Parkinson's disease, and other lifestyle factors. In either crude or adjusted models, serum 25OHD was not associated with blood pressure, whereas increasing PTH levels was associated with higher blood pressure. Men in the highest quartile of serum PTH level had a mean difference of 3.4 mm Hg and 2.8 mm Hg higher in as systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively, than men in the lowest quartile of serum PTH level (P(trend)=0.019 for SBP and <0.001 for DBP). In conclusion, the findings support an association between serum PTH and blood pressure, but not for serum 25OHD in older Chinese men whose vitamin D status is optimal. The lack of association between serum 25OHD and blood pressure may possibly because of the relatively high serum 25OHD levels of the study sample.