补充钾和钙对血压偏高青年动脉血压及钠代谢影响的长期观察

目的　观察在食盐中添加钾和钙降低血压偏高青年动脉血压的作用及其对钠代谢的影响。方法　选取年龄 18～ 2 2岁的 2 2 0名血压偏高青年 ,采用随机、单盲、对照的方法分为补充钾钙组110名 (男 5 8名 ,女 5 2名 ) ,对照组 110名 (男 5 6名 ,女 5 4名 ) ,进行为期 2年的补钾补钙干预对照试验。干预组及其共同生活的家庭成员每人每天补充钾和钙各 10mmol,与食盐混合在一起。结果　经2年期试验 ,补钾补钙组夜 12h尿中K+含量为 ( 4 8± 2 3 )mmol,尿Na+含量为 ( 6 2 4± 2 8 2 )mmol;对照组尿K+含量为 ( 7 8± 3 6 )mmol,尿Na+含量为 ( 71 8± 2 7 5 )mmol,两者比较 ,差异有显著意义。补钾补钙组血压较基线平均下降了 5 3/ 1 8mmHg ,对照组血压较基线上升了 1 3 / 1 7mmHg,二者比较收缩压相差 6 6mmHg ,舒张压相差 3 5mmHg。结论　在家庭日常食盐中适量添加钾和钙 ,可促进钠盐的排泄 ,降低血压偏高青年的动脉血压 ,是有效预防青年高血压的重要途径。     

Dietary approaches to the reduction of blood pressure: The independence of weight and sodium/potassium interventions

This study was designed to determine the feasibility of teaching mildly hypertensive individuals to select a diet, using normally available food products, that either would produce a 5% reduction in percentage of overweight (without altering sodium (Na), potassium (K), or Na:K ratio) or would decrease Na to <70 mEq and increase K to > 100 mEq (without affecting weight) and to compare the resulting changes in blood pressure. Fifty-two participants with mild hypertension were randomly assigned to either a weight-loss or a Na:K intervention. Blood pressure, weight, 3-day diaries, and 24-h urinary excretion of Na and K were measured before and after an 8-week intervention. Participants in the weight-loss intervention had significantly greater changes in weight and calorie intake than those in the Na:K intervention, while changes in Na:K ratio were greatest in the intervention targeted for that change. The percentage of participants who were able to meet the dietary goals is presented and the implications of these data for the selection of dietary goals are discussed.     

Diet and blood pressure in South Africa: Intake of foods containing sodium, potassium, calcium, and magnesium in three ethnic groups

OBJECTIVES: We investigated whether habitual intakes of sodium (Na), potassium, magnesium, and calcium differ across South African ethnic groups, assessed the proportion of Na intake, which is discretionary, and identified which food sources were the major contributors to Na intake. METHODS: This was a cross-sectional study of 325 black, white, and mixed ancestry hypertensive and normotensive subjects. Three repeated 24-h urine samples were collected for assessment of urinary Na, and three corresponding 24-h dietary recalls were administered by trained fieldworkers. Blood pressure and weight were measured at each visit. Secondary analyses were performed on existing dietary databases obtained from four regional surveys undertaken in South African adults. RESULTS: Mean urinary Na excretion values equated to daily salt (NaCl) intakes of 7.8, 8.5, and 9.5 g in black, mixed ancestry, and white subjects, respectively (P < 0.05). Between 33% and 46% of total Na intake was discretionary, and, of the non-discretionary sources, bread was the single greatest contributor to Na intake in all groups. Ethnic differences in calcium intake were evident, with black subjects having particularly low intakes. Urban versus rural differences existed with respect to sources of dietary Na, with greater than 70% of total non-discretionary Na being provided by bread and cereals in rural black South Africans compared with 49% to 54% in urban dwellers. CONCLUSION: White South Africans have higher habitual intakes of Na, but also higher calcium intakes, than their black and mixed ancestry counterparts. All ethnic groups had Na intakes in excess of 6 g/d of salt, whereas potassium intakes in all groups were below the recommended level of 90 mM/d. Dietary differences may contribute to ethnically related differences in blood pressure.     

Dietary magnesium, potassium, sodium, and children's lung function.

To investigate the effects of dietary magnesium, potassium, and sodium on children's lung function, the authors examined cross-sectional dietary data and pulmonary function tests from 2,566 children aged 11-19 years who attended schools in 12 southern California communities during 1998-1999. During school visits, each child completed a health update questionnaire, a validated food frequency questionnaire, and spirometric lung function testing. Low magnesium and potassium intakes were associated with lower lung function. Girls with low magnesium intake had lower forced expiratory flow at 75% of the forced vital capacity (FEF(75)) (-8.3%, 95% confidence interval: -14.8, -1.4) than did girls with higher intake; reductions were larger in girls with asthma (forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75)) (-16.2%, 95% confidence interval: -22.7, -9.1) and FEF(75) (-24.9%, 95% confidence interval: -32.8, -16.1)) than in girls without asthma (FEF(25-75) (-2.0%, 95% confidence interval: -7.4, 3.8) and FEF(75) (-4.1%, 95% confidence interval: -11.3, 3.7)). Boys with low magnesium intake showed deficits in forced vital capacity (-2.8%, 95% confidence interval: -5.4, -0.2) compared with boys with higher intake. The effects of low magnesium intake did not vary substantially in boys with and without asthma. Among girls, low potassium intake was also associated with deficits in forced expiratory volume in 1 second (-2.7%, 95% confidence interval: -5.2, -0.1) and forced vital capacity (-2.4%, 95% confidence interval: -4.7, -0.1). In summary, low magnesium and potassium intakes were associated with lower lung volumes and flows.     

南京市18岁及以上人群膳食钠与钾摄入状况及其与血压的相关性分析

目的 分析南京市城乡居民膳食钠和钾摄入状况及其与血压的相关性。 方法 以多阶段整群随机抽样的方法抽取6个城区1 062户(城市762户,农村300户)18岁及以上居民2 272人,使用连续3 d 24 h膳食回顾法和调味品称重法相结合的方法获得个人膳食钠和钾的摄入量同时进行医学体检获得血压,使用spearman等级相关和多因素logistic回归分析两者的关系。 结果 南京居民每标准人日钠和钾摄入中位数(第25百分位数~75百分位数)分别为4 543.6(3 226.7~6 362.7)mg和1 585.4(1 276.3~2 025.8)mg。实际每日摄入钠3 945.6(2 833.9~5 614.1)mg,钾1 366.6(1 119.2~1 729.1)mg;95.4%的居民膳食钠摄入量超过适宜摄入量(adequate intake,AI),85.3%的居民膳食钾摄入量低于AI值。钠的主要来源是调味品,烹调盐占69.9%,酱油占9.5%;钾主要来源为谷类(21.7%)、蔬菜(32.1%)及肉类(14.3%)。钠钾比值中位数为2.9,其与收缩压和舒张压呈正的等级相关(r_s=0.049,P=0.028;r_s=0.045,P=0.043)。调整人群基本信息、总能量及体质指数,钠钾比第三等份(3.0~4.3)是高血压的危险因素(OR=1.409,95%CI:1.058~1.875,P=0.019)。 结论 南京市居民膳食钠钾严重失衡,属于高钠低钾饮食。膳食中高的钠钾比值是高血压的危险因素。应加强健康教育,提倡低钠高钾膳食。     

浙江省居民膳食钠钾摄入水平

目的分析浙江省居民膳食钠、钾摄入水平。方法运用3d24h回顾法和调味品称重法相结合,对浙江省11个地市共9 798名调查对象进行膳食调查,将食物消费数据结合食物钠、钾含量数据,分析膳食中钠和钾的摄入水平。数据采用SPSS16.0进行统计分析。结果 2～3岁、4～6岁、7～10岁、11～13岁、14～17岁、18～44岁、45～59岁、60岁及以上人群,每日膳食钠摄入中位数(第25百分位数～75百分位数)为4 324(3 258～6 184)mg、4 439(3 135～5 976)mg、4 686(3 345～6 540)mg、4 875(3 518～6 665)mg、4 754(3 452～6 453)mg、4 924(3 504～6 666)mg、5 121(3 776～6 983)mg、5 207(3664～7228)mg;2～3岁、4～13岁、14～17岁、18～44岁、45～59岁、60岁及以上人群,每日膳食钾摄入中位数(25百分位数～75百分位数)分别为779(571～1106)mg、953(686～1331)mg、1137(855～1566)mg、1354(986～1795)mg、1528(1132～1953)mg、1644(1269～2159)mg、1660(1289～2226)mg、1571(1162～2155)mg。相比城市居民,农村居民摄入更多的钠和更少的钾。相比内陆地区,沿海地区居民摄入更多的钠,差异具有统计学意义。约82.0%的膳食钠来源于食盐、酱油;蔬菜和水果提供了膳食钾中的25%,谷类提供了27.8%,豆类提供12.2%的膳食钾。结论浙江省居民膳食钠摄入过量,膳食钾摄入不足。应该进行营养干预,以达到人群膳食钠、钾摄入平衡。     

Dietary sodium intake deleteriously affects blood pressure in a normotensive population

Western dietary pattern, and particularly high dietary sodium intake (DSI), is recognized for its detrimental impact on blood pressure (BP). This paper examined the association of DSI with BP in Nunavik Inuit (Québec), a population known to have an optimal BP on average. In a population-based study, we recruited 421 normotensive participants aged 18-74 years from 14 coastal villages, situated north of the 55th parallel. BP, biochemistry and anthropometry were obtained. DSI was assessed by a 24-h dietary recall. Mean (s.e.) DSI was higher in men than in women (2358 (101) vs. 1702 (100) mg/d, P<0.0001). Similar gender difference was found in systolic BP (118 (0.7) vs. 111 (0.6) mm?Hg; P<0.0001). After adjustment for confounders, we found a positive association between BP and DSI (all P<0.05). In a normotensive population, BP shows a linear relationship with DSI. Our results emphasize the potent deleterious impact of DSI on BP.     

Dietary fibre,blood pressure and plasma cholesterol

Blood pressure and plasma cholesterol were measured in 300 customers of health food shops, many of whom had a high intake of dietary fibre. Blood pressure tended to be lower in subjects consuming high quantities of cereal fibre; it was estimated that systolic and diastolic pressures were lower by 4 and 3mmHg respectively for every 100g/week (14g/day) increase in cereal fibre. Total plasma cholesterol tended to be lower at high levels of intake of fruit and vegetable fibre, amounting to a decrease of 0.3mmol/1 for every 100g/week increase in fibre. These effects were not explained by vegetarianism.     

Dietary salt and blood pressure

Research evidence on the role of dietary sodium in the etiology and pathogenesis of hypertension is briefly reviewed. This matter is assuming new importance at present, given new data on the efficacy of normalization of blood pressure for adults with so-called "mild" hypertension (average diastolic 90-104 mm Hg), hence the need for safe nutritional-hygienic alternatives to years-long drug treatment for millions of people with such hypertension. Two trials by the authors deal with some unresolved questions in this area. The first, a preliminary study, involved 21 lacto-ovo-vegetarian high school students living in a boarding school. With decrease in daily Na intake from 216 to 72 meq for the experimental compared with the control group, red blood cell Na concentration was significantly lower in the former; systolic pressure was slightly but not significantly lower. The second trial, the Primary Prevention of Hypertension, involves over 200 hypertension-prone persons aged 30-44, and explores the ability in the experimental group to reduce blood pressure and prevent development of hypertension by safe nutritional-hygienic means (weight reduction, dietary Na decrease, avoidance of excess alcohol, rhythmic exercise). Initial results at 6 months are presented. Trials on the prevention and control of hypertension by nonpharmacologic means, including reduced Na intake, and involving analyses of the inter-relationships among dietary Na, other dietary factors, Na metabolism, and blood pressure in samples from different population strata, are an important present-day research need.     

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.     

Dietary sodium and potassium intake and colorectal cancer risk

Abstract

In a large, comprehensive, population‐based case‐control study of colorectal cancer (The Melbourne Colorectal Cancer Study), a high intake of sodium was shown to be a statistically significant risk factor for rectal cancer in males (RR = 1.72, p = 0.07; and was close to statistical significance in females (RR = 7.55, p = 0.06). This was independent of previously described dietary risk factors and also independent of the previously described beer risk. A high intake of potassium was protective for both males and females, but this effect disappeared after adjustment was made for the previously described dietary risk factors. A high ratio of dietary potassium to sodium was a statistically significant protective factor in females for both colon and rectal cancer, and the significance of this effect was reduced after adjustment was made for the previously described dietary risk factor (RR for colon cancer = 0.70, p = 0.08; RR for rectal cancer = 0.67, p = 0.08). So far, no biological explanations are available for these associations, and while they are of obvious etiologic interest, they should be interpreted with caution.     

Dietary sodium and potassium intake and colorectal cancer risk

In a large, comprehensive, population-based case-control study of colorectal cancer (The Melbourne Colorectal Cancer Study), a high intake of sodium was shown to be a statistically significant risk factor for rectal cancer in males (RR = 1.72, p = 0.01) and was close to statistical significance in females (RR = 1.58, p = 0.06). This was independent of previously described dietary risk factors and also independent of the previously described beer risk. A high intake of potassium was protective for both males and females, but this effect disappeared after adjustment was made for the previously described dietary risk factors. A high ratio of dietary potassium to sodium was a statistically significant protective factor in females for both colon and rectal cancer, and the significance of this effect was reduced after adjustment was made for the previously described dietary risk factor (RR for colon cancer = 0.70, p = 0.08; RR for rectal cancer = 0.67, p = 0.08). So far, no biological explanations are available for these associations, and while they are of obvious etiologic interest, they should be interpreted with caution.     

Relationship of urinary sodium/potassium excretion and calcium intake to blood pressure and prevalence of hypertension among older Chinese vegetarians

OBJECTIVE: To examine the associations of dietary sodium and potassium, as reflected by the urinary sodium/potassium excretion, and calcium intake with blood pressure and the prevalence of hypertension among older Chinese vegetarians in Hong Kong. DESIGN: Cross-sectional study. SETTING: Research clinic in a teaching hospital in Hong Kong. SUBJECTS: A total of 111 ambulatory vegetarians over the age of 55 were recruited from members of religious organizations or old age hostels. MAIN OUTCOME MEASURES: Hypertension was defined as supine blood pressure >140/90 mmHg or a history of hypertension. Dietary sodium, potassium and calcium intakes were assessed by 24 h recall method or fasting urinary sodium or potassium/creatinine ratios. RESULTS: Seventy-one subjects (64%) were found to have hypertension. Compared with normotensive subjects, hypertensive subjects had lower calcium intake (411+/-s.d. 324 vs 589+/-428 mg, P=0.04), but higher urinary sodium/creatinine ratio (32.6+/-19.3 vs 21.0+/-12.4, P=0.00) and sodium/potassium ratio (4.7+/-2.8 vs 3.4+/-2.3, P=0.02). Among 88 subjects not taking diuretics or antihypertensive drugs, systolic blood pressure was related to calcium intake (r=-0.40), urinary sodium/creatinine ratio (r=0.39), urinary sodium/potassium ratio (r=0.30) and age (r=0.23). Diastolic blood pressure was related to urinary sodium/creatinine (r=0.29). Twenty-three subjects with high urinary sodium/potassium and low calcium intake and 16 subjects with low urinary sodium/potassium ratio and high calcium intake differed markedly with respect to systolic blood pressure (159+/-26 vs 130+/-15 mmHg) and prevalence of hypertension (78% vs 25%). CONCLUSIONS: Older Chinese vegetarians are predisposed to hypertension because of their sodium-rich but calcium-deficient diets.     

Dairy products, calcium, and blood pressure

The previously reported inverse association of dietary calcium intake and blood pressure levels was examined in a Southern California community, in order to determine whether this association was independent of age, obesity, and alcohol consumption. In the total population significantly less calcium intake from milk was reported in hypertensive versus normotensive men (but not women) and the association was independent of age and obesity. In a 23% subsample of men from this cohort the effect of total dietary calcium intake from all dairy products was estimated from a 24-h dietary recall. Again hypertensive men consumed significantly less calcium than normotensives. In men, both systolic and diastolic blood pressure levels were inversely associated with calcium intake from dairy products. After controlling for age, obesity, and alcohol, diastolic blood pressure was negatively and significantly associated with total calcium intake from dairy products, while systolic blood pressure was similarly associated with whole milk calcium alone. Although these data are cross-sectional, they suggest that some component of dairy products, probably calcium, exerts a protective effect against hypertension, and are compatible with the protective effect of calcium reported in hypertension-prone rats.     

Dietary calcium intake is inversely associated with blood pressure in Brazilian children

This study aimed to evaluate the dietary calcium intake and its association with blood pressure in childhood. It is a cross-sectional study with a sample of 347 Brazilian children aged 8 and 9 years. We evaluated calcium intake through three dietary records. Blood pressure was measured following the recommendations of the Brazilian Society of Cardiology. The intake of calcium was below recommendations for almost all children (96.3%). There was statistically significant difference in the means of systolic (p?=?.041) and diastolic (p?=?.047) blood pressure in the tertiles of calcium intake. After adjustment of regression model, each tertile of calcium intake showed that the systolic and diastolic blood pressure was reduced in 1.53 (95% confidence interval: ?2.84 to ?0.21) and 1.83?mmHg (95% confidence interval: ?3.49 to ?0.19), respectively. Our results showed an inverse association between dietary calcium intake and blood pressure in childhood.     

Dietary sodium and potassium in the genesis, therapy, and prevention of hypertension

In this review, we first summarized the evidence from animals and man for and against a role for dietary sodium in the genesis and treatment of hypertension. The evidence for a role for dietary sodium in the genesis of hypertension is strongest in those subjects with impaired ability to excrete sodium due to organic renal disease or mineralocorticoid excess. Here restriction of dietary sodium promptly lowers arterial pressure. Its role in the genesis of essential hypertension is still controversial. Nevertheless, it appears that some patients with mild to moderate essential hypertension respond to moderate sodium restriction with a modest fall in blood pressure. This restriction also seems to reduce the amount of antihypertensive medication needed to keep blood pressure under control. We next considered the mechanism of the pressure response to dietary sodium chloride, concentrating upon the increase in extracellular fluid volume, potassium depletion, and increased plasma levels of prohypertensive sodium pump inhibitor and antihypertensive atrial natriuretic factor. We next summarized the evidence for a primary role for dietary potassium in the genesis of hypertension and pointed out that certain subsets of subjects with a high incidence of hypertension also have a lower dietary potassium intake. Some investigators find that dietary potassium supplementation lowers blood pressure in established hypertension. This may result from natriuresis and from vasodilation subsequent to stimulation of Na+, K+-ATPase in vascular smooth muscle and adrenergic nerve terminals. We then considered practical aspects of dietary sodium restriction and dietary potassium supplementation in the therapy for established hypertension. The review concludes with comments on their possible roles in the prevention of hypertension.