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Data indicate an inverse association between dietary calcium and magnesium intakes and blood pressure (BP); however, much less is known about associations between urinary calcium and magnesium excretion and BP in general populations. The authors assessed the relation of BP to 24-hour excretion of calcium and magnesium in 2 cross-sectional studies. The International Study of Macro- and Micro-Nutrients and Blood Pressure (INTERMAP) comprised 4,679 persons aged 40-59 years from 17 population samples in China, Japan, the United Kingdom, and the United States, and the International Cooperative Study on Salt, Other Factors, and Blood Pressure (INTERSALT) comprised 10,067 persons aged 20-59 years from 52 samples around the world. Timed 24-hour urine collections, BP measurements, and nutrient data from four 24-hour dietary recalls (INTERMAP) were collected. In multiple linear regression analyses, urinary calcium excretion was directly associated with BP. After adjustment for multiple confounders (including weight, height, alcohol intake, calcium intake, urinary sodium level, and urinary potassium intake), systolic BP was 1.9 mm Hg higher per each 4.1 mmol per 24 hours (2 standard deviations) of higher urinary calcium excretion (associations were smaller for diastolic BP) in INTERMAP. Qualitatively similar associations were observed in INTERSALT analyses. Associations between magnesium excretion and BP were small and nonsignificant for most of the models examined. The present data suggest that altered calcium homoeostasis, as exhibited by increased calcium excretion, is associated with higher BP levels. Am J Epidemiol

Findings from observational and interventional studies on the relationship of dietary linoleic acid, the main dietary polyunsaturated fatty acid, with blood pressure have been inconsistent. The International Study of Macro-Micronutrients and Blood Pressure is an international cross-sectional epidemiological study of 4680 men and women ages 40 to 59 years from 17 population samples in China, Japan, United Kingdom, and United States. We report associations of linoleic acid intake of individuals with their blood pressure. Nutrient intake data were based on 4 in-depth multipass 24-hour dietary recalls per person and 2 timed 24-hour urine collections per person. Systolic and diastolic blood pressures were measured 8 times at 4 visits. With several models to control for possible confounders (dietary or other), linear regression analyses showed a nonsignificant inverse relationship of linoleic acid intake (percent kilocalories) to systolic and diastolic blood pressure for all of the participants. When analyzed for 2238 "nonintervened" individuals (not on a special diet, not consuming nutritional supplements, no diagnosed cardiovascular disease or diabetes, and not taking medication for high blood pressure, cardiovascular disease, or diabetes), the relationship was stronger. With adjustment for 14 variables, estimated systolic/diastolic blood pressure differences with 2-SD higher linoleic acid intake (3.77% kcal) were -1.42/-0.91 mm Hg (P

We aimed to assess cross-cultural validity of the reporting of respiratory symptoms in the European Community Respiratory Health Study (ECRHS). A random sample of subjects from the general population (aged 20-44 yr), from 35 centers in 15 countries, answered a questionnaire and underwent allergy tests and airway challenge with methacholine. The overall response rate to the questionnaire was 60% (n = 16,635). Exploratory factor analysis was used to identify how symptoms were grouped (i.e., to specify factor structure), using data from the United Kingdom. Subsequently, a confirmatory factor analysis of the prespecified structure for the United Kingdom was assessed for each country in consecutive nested models, increasing at each step the number of parameters forced to be equal to the United Kingdom, and assessing the goodness of fit. Variables were clustered in the same four groups (factors) in all countries. The four factors, mutually adjusted, were associated with either bronchial responsiveness, atopy, or smoking, which provides coherence for the separation of the four factors. In the confirmatory factor analysis, when the load of each of the symptoms in the corresponding factor was prespecified, all countries except Spain showed an adequate fit; in Spain there were differences in answers concerning asthma treatment. We conclude that the ECRHS multilingual translated respiratory symptoms questionnaire shows high internal consistency, suggesting that international comparisons are not affected by errors due to cross-cultural variations in the reporting of symptoms.

OBJECTIVES--To assess further the relation in Intersalt of 24 hour urinary sodium to blood pressure of individuals and populations, and the difference in blood pressure from young adulthood into middle age. DESIGN--Standardised cross sectional study within and across populations. SETTING--52 population samples in 32 countries. SUBJECTS--10,074 men and women aged 20-59. MAIN OUTCOME MEASURES--Association of sodium and blood pressure from within population and cross population multiple linear regression analyses with multivariate correction for regression dilution bias. Relation of sample median daily urinary sodium excretion to difference in blood pressure with age. RESULTS--In within population analyses (n = 10,074), individual 24 hour urinary sodium excretion higher by 100 mmol (for example, 170 v 70 mmol) was associated with systolic/diastolic blood pressure higher on average by 3/0 to 6/3 mm Hg (with and without body mass in analyses). Associations were larger at ages 40-59. In cross population analyses (n = 52), sample median 24 hour sodium excretion higher by 100 mmol was associated with median systolic/diastolic pressure higher on average by 5-7/2-4 mm Hg, and estimated mean difference in systolic/diastolic pressure at age 55 compared with age 25 greater by 10-11/6 mm Hg. CONCLUSIONS--The strong, positive association of urinary sodium with systolic pressure of individuals concurs with Intersalt cross population findings and results of other studies. Higher urinary sodium is also associated with substantially greater differences in blood pressure in middle age compared with young adulthood. These results support recommendations for reduction of high salt intake in populations for prevention and control of adverse blood pressure levels.

Asthma is a common chronic disorder which may be increasing in prevalence. However, little is known of its distribution and determinants. The European Community Respiratory Health Survey (ECRHS) is a multicentre survey of the prevalence, determinants and management of asthma. This paper presents a descriptive account of the variation in self-reported attacks of asthma and asthma symptoms across Europe, and in part fulfils the first aim of the study. A screening questionnaire, including seven questions relating to the 12 month prevalence of symptoms of asthma, was distributed to representative samples of 20-44 year old men and women in 48 centers, predominantly in Western Europe. The median response rate to the questionnaire was 75% but, after removing from the denominator those who were the wrong age, were known to have moved out of the area, or had died, it was 78% (range 54-100). The prevalence of all symptoms varied widely. Although these were generally lower in northern, central and southern Europe and higher in the British Isles, New Zealand, Australia and the United States, there were wide variations even within some countries. Centres with a high prevalence of self-reported attacks of asthma also reported high prevalences of nasal allergies and of waking at night with breathlessness. The use of asthma medication was more common where wheeze and asthma attacks were more frequent. In most centres in The Netherlands, Sweden, New Zealand and the United Kingdom over 80% of those with a diagnosis of asthma were currently using asthma medication. In Italy, France and Spain the rate was generally less than 70%. These data are the best evidence to date that geographical differences in asthma prevalence exist, are substantial and are not an artefact of the use of noncomparable methods.

The time course of the changes in serum lipid and lipoprotein levels have been studied in 100 patients undergoing coronary artery bypass surgery. Marked decreases occur in the levels of cholesterol (-45%), HDL-cholesterol (-35%), LDL-cholesterol (-53%), Apo A1 (-43%) and Apo B (-43%) on the third day after the operation. In the control group the values gradually returned to preoperative levels which are reached after three months. Three months after the intervention, in the pravastatin-treated group (20 mg/day) the values of total cholesterol (-20%), LDL-cholesterol (-28%) and Apo B (-22%), remained significantly lower than in the control group (p 0.0001) and were lower over the whole duration of the study. The postoperative time course of HDL-cholesterol and Apo A1, however, was not significantly influenced by the administration of pravastatin.