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.     

短期摄入负荷量食盐对健康男青年血压的影响

目的探讨膳食高盐对健康男青年血压的影响。方法集体进餐的健康男性320例,分A、B观察组与对照组。观察基线、低盐、盐负荷期血压。在低盐与盐负荷期末测A组血钠。结果各组基线血压无显著差异(P>0.05),低盐期血压较基线下降(P<0.05)。观察组盐负荷期与基线、低盐期相比收缩压与舒张压升高有显著意义(P<0.05)。观察组与对照组间血压差异有显著意义(P<0.05)。摄盐前后血钠差异无显著意义(P>0.05)。结论由于肾脏的调节功能,短期膳食限盐与高盐对健康男青年血钠影响不明显,但对血压产生的影响是有意义的,膳食高盐显著升高健康青年人的血压。     

The independent effect of habitual cigarette and coffee consumption on blood pressure

The authors investigated the possible relation between habitual cigarette and coffee consumption and blood pressure (BP) levels in 7506 men and 2095 women. The study population were managers and employees examined in northern Italy between 1986–1988. In particular, the hypothesis of a substantial independence between smoking-BP and coffee-BP was tested. BP levels were corrected for age, body mass index, physical activity, and alcohol consumption by analysis of covariance. Significantly, smoking was inversely related to BP, both in men (SBP, P < 0.001, DBP, P < 0.001) and women (SBP, P = 0.001, DBP, P = 0.012). In particular, the BP of non-smoking men, SBP/DBP, was 131.0/83.5, whereas in male smokers up to and over 20 cigarette/day, BP was 128.1/82.0 and 128.1/82.1 respectively. Coffee consumption was related to BP levels in men (SBP, P < 0.001; DBP, P = 0.009), but not in women (SBP, P = 0.320; DBP, P = 0.982). BP in male subjects was 131.3/83.5 in non-drinkers, 130.7/83.3 in those drinking 1–3 cups/day, 128.4/82.6 and 127.2/81.8 in drinkers of 4–5 and over 5 cups/day, respectively. No significant interactions were demonstrated, thus the relationship between habitual smoking and coffee consumption with BP appears to agree with an additive model.Corresponding author.     

短期摄入负荷量食盐对健康男青年血压的影响

目的探讨膳食高盐对健康男青年血压的影响.方法集体进餐的健康男性320例,分A、B观察组与对照组.观察基线、低盐、盐负荷期血压.在低盐与盐负荷期末测A组血钠.结果各组基线血压无显著差异(P＞0.05),低盐期血压较基线下降(P＜0.05).观察组盐负荷期与基线、低盐期相比收缩压与舒张压升高有显著意义(P＜0.05).观察组与对照组间血压差异有显著意义(P＜0.05).摄盐前后血钠差异无显著意义(P＞0.05).结论由于肾脏的调节功能,短期膳食限盐与高盐对健康男青年血钠影响不明显,但对血压产生的影响是有意义的,膳食高盐显著升高健康青年人的血压.     

Habitual coffee consumption and blood pressure: A study of self-defense officials in Japan

The study aims to examine the relationship between habitual coffee consumption and blood pressure. The subjects were 3336 male self-defense officials aged 48–56 years, who received a preretirement health examination at the Self-Defense Forces Fukuoka Hospital between October 1986 and December 1992. Average coffee intake in the past year was ascertained by a self-administered questionnaire. A significant inverse relation between habitual coffee consumption and blood pressure was found with and without adjustment for alcohol use, cigarette smoking, body mass index, glucose tolerance, and green tea intake. Green tea, another major source of caffeine intake in Japanese, was unrelated to blood pressure. The adjusted mean differences per cup of coffee consumed per day were –0.6 mmHg (95% confident interval [CI]: –0.9 to –0.3, p=0.0001) in systolic blood pressure and –0.4 mmHg (95% CI: –0.5 to –0.2, p=0.0002) in diastolic blood pressure. Habitual coffee drinkers had lower blood pressure than non-drinkers at any levels of alcohol use, cigarette smoking, obesity, and glucose intolerance. Our findings consolidate the previous observation that habitual coffee consumption was associated with lower blood pressure.     

Familial resemblance in the blood pressure response to sodium restriction

Familial resemblance in the blood pressure response to sodium restriction in normotensive persons was investigated. Forty-four families of identical twin children participated in a sodium restriction (less than or equal to 75 meq/day) protocol for a period of 12 weeks. Subjects were residents of central Indiana, and the study was conducted over a three-year period. Parent-offspring and sibling-sibling resemblances for actual blood pressure were not different under conditions of ad lib sodium intake versus sodium restriction. Mother-offspring resemblance in blood pressure change with sodium restriction was significant for systolic (p less than 0.001), diastolic (p less than 0.05), and mean arterial (p less than 0.05) pressures. Sibling-sibling and twin-twin resemblances were also highly significant for the change in all three blood pressures. Father-offspring resemblances were marginal (p less than 0.10). This study is, to the author's knowledge, the first to demonstrate significant familial resemblances in blood pressure change with sodium restriction in normotensive persons.     

医学院校高血压控制状况调查分析

目的 了解院校高血压患者的血压控制状况与其它心脑血管病危险的关系，为有效防治高血压提供依据。方法 对160例高血压患者进行随访调查，按照《中国高血压防治指南》和Holloway的脑血管病循证医学达标模式进行比较。结果 参照国家指南标准，经治疗后血压达标率为45％，55％的患者治疗后未达到目标血压；高血脂治疗达标率仅为5．2％，94．8％的患者经过治疗血脂仍超标；高血压患者均伴有不同程度的其它心脑血管病危险，其排列顺序为高血脂、高血糖、高尿酸、冠心病、糖尿病、脑卒中；不能有效降低血压的患者心脑血管病危险明显高于有效降压组，尤其显著高于血压降至理想组。结论 有效降血压可明显降低心脑血管病的危险，应严格按相关指南防治高血压。     

Variability in blood pressure response to dietary sodium intake among African green monkeys (Cercopithecus aethiops)

Since salt-sensitivity to blood pressure (BP) response is a species-related phenomenon, the response of BP to dietary sodium was examined in 14 adult male African green monkeys (Cercopithecus aethiops). The animals were exposed to graded increase of dietary NaCl at 0 (control), 3.0, 4.5, and 6.0%, respectively for 45, 139, 37, and 90 days. Systolic and diastolic BP and body weights were measured twice weekly. Body weight did not differ significantly between successive diets. The mean (+/- SD) systolic/diastolic BP for control, 3.0, 4.5, and 6.0% NaCl diets were 88.8 +/- 15.4/65.9 +/- 13.7, 101.9 +/- 17.6/72.1 +/- 13.0, 90.5 +/- 20.9/62.2 +/- 16.2, and 115.3 +/- 22.6/81.0 +/- 16.4, respectively. BP changes between successive diets were significant (p less than 0.05). Monkeys with high or low initial mean arterial BP levels on control diet tended to maintain the same order with significantly high correlations between BP levels for successive diet periods (r = 0.88 to 0.95, p less than 0.0001). Thus as a group, this nonhuman primate species responds to increased NaCl intake with elevated mean systolic and diastolic BP. Individual variations in salt sensitivity and consistency in persistence of BP levels in this species has bearing on human hypertension.     

Measurement of sodium intake and its relationship to blood pressure and salivary sodium concentration

The mean daily sodium intake was determined for 33 normotensive subjects by analysis of a 7 day 24 h urine collection. The intake range was 1.75–5.77 g Na/day with an intra-individual standard deviation of 1.08 g Na and an inter-individual standard deviation of 0.80 g Na giving a ratio of intra-to inter-individual variance of 1.82, 79% of the subjects were correctly classified into the approapriate tertile for sodium intake after the 7 day collection. The intake range for potassium was 1.54 to 4.2 g/day.No relationship was observed between blood pressure and sodium or potassium intake. Salivary sodium levels (both stimulated and unstimulated) were positiviely correlated with sodium excretion of the day preceding saliva collection.     

Comparison of salty taste acuity and salty taste preference with sodium intake and blood pressure based on zinc nutritional status in two rural populations in Korea

This study examined salty taste acuity and salty taste preference and sodium intake in relation to zinc nutritional status in 2 rural populations in Korea. And we also examined the main food contributors of their sodium intakes. We enrolled 218 adults (66 men and 152 women) from the Kangneung and Samcheok regions in Korea''s Kangwon province in our study conducted from December 2011 to February 2012. Participants from each region were divided into 3 groups based on their serum zinc level (T1: lowest, T2: intermediate, T3: highest). We compared the salty taste acuity and preference, Na index (Dish Frequency Questionnaire for estimation of habitual sodium intake), blood pressure, and intakes of nutrients including sodium by 3 groups of serum zinc level. The results were as follows: a higher serum zinc level indicated a lower sodium intake and Na index (P < 0.05). The salty taste acuity was considerably higher for participants from the Kangneung region than those from the Samcheok region (P < 0.05). And the serum zinc level was significantly higher in participants from the Kangneung region than those from the Samcheok region (P < 0.05). We further divided the participants into 2 groups: those who consumed more zinc than the recommended intake (RI) and the others. We compared salty taste acuity and salty taste preference in the 2 groups. The salty taste threshold and palatable salty taste concentrations were lower for the group with a zinc intake above RI than for the group with zinc intake below the RI. However, the difference was not significant. This study confirms that taste function differs depending on zinc nutritional status. In future, it is required to a large-scale, long-term, prospective study on the correlation between zinc intake, serum zinc levels, and taste perception function and blood pressure.     

Relation of coffee,green tea,and caffeine intake to gallstone disease in middle-aged Japanese men

A possible protective effect of coffee or caffeine intake in the formation of gallstones has been suggested in some epidemiological studies. We examined the relation of coffee, green tea, and caffeine intake to gallstone disease in middle-aged Japanese men, distinguishing known gallstones from unknown diagnosed gallstones. Study subjects were 174 cases of gallstones as determined by ultrasonography, 104 cases of postcholecystectomy, and 6889 controls of normal gallbladder in the total of 7637 men who received a health examination at four hospitals of the Self-Defense Forces (SDF). Of the 174 cases of prevalent gallstones, 50 had been aware of having gallstones. Previously diagnosed gallstones and postcholecystectomy were combined as known gallstone disease. The consumption of coffee and green tea was ascertained by a self-administered questionnaire, and caffeine intake was estimated. Statistical adjustment was done for body mass index, smoking, alcohol use, rank in the SDF, and hospital. Coffee and caffeine intake were associated each with a statistically significant increase in the prevalence odds of known gallstone disease, but unrelated to newly diagnosed gallstones. Adjusted odds ratios of known gallstone disease were 1.7 (95% confidence interval [CI] 1.1–2.8) for coffee consumption of five cups or more per day vs. no consumption and 2.2 (95% CI: 1.3–3.7) for caffeine intake of 300 mg/day or more vs. less than 100 mg/day. The consumption of green-tea showed no material association with either unknown gallstones or known gallstone disease. The findings do not support a hypothesis that coffee drinking may be protective against gallstone formation.     

Subjective evaluation of the frequency of salty food intake and its relationship to urinary sodium excretion and blood pressure in a middle-aged population

Objectives

The aim of this study was to examine the relationship between subjective evaluations of the frequency of salty food intake and both urinary sodium excretion and blood pressure (BP) in a middle-aged population.

Methods

Urinary sodium and creatinine concentrations in a spot sample and brachial BP were measured in 419 subjects (mean age 37 ± 9 years, 385 men) during a health examination at a company in Kanagawa, Japan, 2011. Twenty-four-hour urinary sodium excretion was estimated from sodium and creatinine concentrations in the spot sample. The subjects were asked about the frequency of salty food intake on a self-reported questionnaire, choosing their answer from ‘seldom’, ‘sometimes’, or ‘always’ based on their own subjective evaluation. The amount of daily salt intake was converted from 24-h urinary sodium excretion.

Results

The prevalence of high salt intake, defined as greater than the daily average salt intake of Japanese according to the National Health and Nutrition Survey in 2010, gradually increased from the ‘seldom’ to the ‘sometimes’, and then ‘always’ categories (10.3, 13.4, and 24.0 %, respectively; P = 0.013 for trend). The 24-h urinary sodium excretion among these groups also tended to be different; however, the differences did not reach a significantly significant level (145 ± 41, 152 ± 34, and 160 ± 40 mEq/day, respectively; P = 0.076). Both systolic and diastolic BP were similar among the groups.

Conclusions

Although some of our findings raise the possibility of a relationship between a subjective evaluation of the frequency of salty food intake and urinary sodium excretion, further studies are needed to confirm the relationship. In contrast, no relationship with BP was found.     

Calcium intake and the relationship of dietary sodium and potassium to blood pressure

Using First National Health and Nutrition Examination Survey (NHANES I) data, we studied the relationships of dietary sodium, potassium, and alcohol to blood pressure in relation to levels of dietary calcium intake. At low Ca intakes (less than 400 mg/d for men and less than 800 mg/d for women) the ratio of Na to K (Na:K) was significantly related to blood pressure (p less than 0.01) after controlling for age, body mass index (BMI), race, and gender. At higher Ca intakes neither Na:K nor any other nutrient (with the exception of alcohol) was related to either systolic or diastolic blood pressures. Na:K was more strongly related to blood pressure than either nutrient alone and low Ca intakes were necessary for the Na:K-blood pressure relationship to be evident. Interaction of these three dietary factors in relation to blood pressure was evident in all race and gender groups. Associations of age, BMI, gender, and alcohol with blood pressure were not affected by Ca levels.     

Association of dietary sodium intake and blood pressure in the German population

Aim

The present study investigated the association of dietary sodium intake and blood pressure (BP) based on existing data from the German National Health Interview and Examination Survey (GNHIES) and the associated German Nutrition Survey (GeNuS).

Subject and methods

After exclusion of participants with known hypertension and/or anti-hypertensive medication use, complete data of the GeNuS subsample of the 1998 GNHIES were analysed for 1,539 men and 1,553 women aged 18–79?years. The survey included a health and lifestyle questionnaire, a medical examination and a comprehensive diet history interview. Sodium density (g/1,000?kcal) was examined in quartiles of systolic and diastolic BP (SBP and DBP). Multiple linear regression models were used to investigate associations of sodium density and SBP or DBP. Adjustments were made for sex, age and socio- and health-behavioral risk factors previously found to be related to BP in univariate analysis.

Results

Participants with a high SBP and DBP (fourth quartile of SBP: ≥ 142?mmHg in men; ≥ 139?mmHg in women) had a significantly higher dietary sodium intake than individuals with a lower BP. In the multiple models, both SBP and DBP were significantly associated with sodium density when adjusted for other factors such as sex, age, body mass index and alcohol consumption.

Conclusion

An association of dietary sodium intake and BP in the German population could be found. Further research using sodium data collected via 24-h urine samples is urgently needed for evidence-based public health policy reducing risk of BP associated morbidities and mortalities in Germany.     

Effect of coffee feeding on the duodenal transport and bile excretion of calcium in the rat

Caffeine administration increases endogenous fecal calcium and urinary calcium excretion resulting in a deterioration of calcium balance. The aim of the current study was to investigate the effect of coffee feeding on the intestinal transport of calcium and the mechanism of enhancement of endogenous calcium secretion. A group of rats were fed a diet containing 4% instant coffee and their calcium metabolism was compared to a control group fed the same diet with cellulose replacing the instant coffee. The results of the calcium balance study showed that 3 weeks of coffee consumption caused an increase in endogenous fecal calcium and urinary calcium excretion without a change in the absorption coefficient of calcium. We used an in vivo ligated loop technique to fractionate the calcium of the bile from that of the mucosal efflux and pancreatic secretions. The results indicated that the enhancement of endogenous calcium secretion into the duodenal lumen was from an increase in bile secretion and in mucosal efflux. When the bile flow rate was measured by direct cannulation of the bile duct, we were able to demonstrate that chronic coffee feeding resulted in a 45% increase in the bile flow rate without a change in the calcium concentration in the bile fluid.     

Reduction in sodium chloride intake: effects on urinary Na, K and aldosterone output in healthy free-living adults

Eleven healthy free-living adults (six women, five men) weighed and recorded all food and drink consumed and collected all urine for two non-consecutive 7-day periods whilst eating their usual diet (Period 1) and attempting to reduce salt intake (Period 2). Bread (including pitta bread) provided on average a quarter of total Na intake of subjects in Period 1 so that wholemeal bread made without added salt was made available in Period 2. All subjects achieved substantial reductions (mean 65%) in Na intake in Period 2 with no change in K intake so that the Na:K molar ratio fell from 1.3 to 0.5. Urinary Na output closely followed intakes and there was a large increase (mean 11.2 μg/d) in aldosterone excretion with a non-significant increase in K output. Simple linear relationships which allow prediction of Na and K intake from the more easily measured urinary output were derived.     

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。     

Influence of coffee on the excretion of noradrenaline and adrenaline in urine

Summary In field studies, the excretion rate of urinary catecholamines is very often used as an indicator of strain. Interfering effects which are due to caffeine, for example, can only be quantified if the influence of coffee consumption on the excretion of catecholamines is known quantitatively. This was the aim of our study with five subjects, on five consecutive working days, and with a strict standardization of nutrition. The urine samples were specified with respect to the following parameters: sampling period, volume, urine status, density, creatinine, noradrenaline, and adrenaline. Adrenaline showed a significant correlation with coffee consumption, whereas noradrenaline did not. Moreover, it could be demonstrated that relating the concentration of catecholamines to the creatinine excretion is insufficient for work physiology studies, especially if the urine sampling periods are as short as 2h.This study was supported by the Deutsche Forschungsgemeinschaft, Bad Godesberg (Ru 240/5-1)     

有氧运动对高血压患者血压及血浆内皮素水平的影响

目的 探讨有氧运动对原发性高血压患者血压及血浆内皮素水平的影响。方法 84例原发性高血压病患者，分为训练组52例和对照组32例。训练组进行为期7周，每周6次，每次1h的有氧运动。结果 训练组患者运动后血压及血浆内皮素水平显著下降，对照组无明显变化。结论 运动训练可以降低原发性高血压患者的血压及血浆内皮素水平。