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Specific causes of death were analyzed for 10,908 participants in the Hypertension Detection and Follow-up Program, to explore possible explanations for the observed excess 8.3-year mortality from all causes in hypertensives with low body mass. Although the cardiovascular mortality rate among men in the lowest decile of body mass (body mass index 21.96 or less) was 50% higher than that of men in the median class (body mass index 26.4-28.8), death rate for noncardiovascular deaths was more than 2 1/2 times higher in men with lean versus median body mass. The pattern was similar among women. Among noncardiovascular causes, striking differences in mortality rates between lean hypertensives and those of average body mass were observed for cirrhotic death (relative risk of 12+ in men and 11+ in women), for nonmalignant respiratory disease in men (relative risk of 7+), for violent death (both sexes), and for malignant neoplasms in men. Prevalence of smoking was almost twice as high in the lowest compared with the median body mass group; among the lean, excess deaths, particularly noncardiovascular deaths, were concentrated among smokers. Thus, male smokers in the lowest decile of body mass constituted only 3% of the study population, but contributed 8% of all deaths, 11% of all noncardiovascular deaths, and 22% of all cirrhotic deaths. A larger proportion of deaths occurred early in follow-up in the lean versus other hypertensives, suggesting occult disease among the lean at baseline. There was no evidence that more severe or treatment-resistant hypertension was present in or could explain excess mortality among the hypertensives with low body mass. The inference from the findings is not that overweight is protective for hypertensives nor that excess risk is due to leanness per se. Rather, a reasonable hypothesis, particularly from findings on specific causes of death, is that excess mortality in lean hypertensives is due to deleterious lifestyles, particularly smoking and excess alcohol intake, contributing to both leanness and risk of death.

The association between hypertension and a number of cardiovascular disease risk factors was assessed in the large population sample of Gubbio, a town in central Italy that dates back to medieval times. The data confirm those of previous studies showing that hypertension is strongly associated with other metabolic abnormalities, such as markedly overweight subjects, hyperuricaemia, hyperglycaemia, hypercholesterolaemia, that may be related to the aetiopathogenesis of high blood pressure and, in addition, compound the risk of major clinical cardiovascular events in people with hypertension. The findings are therefore relevant for prevention strategies. In addition, the association between erythrocyte sodium-stimulated lithium countertransport and hypertension is being studied.

INTERSALT, an international cooperative study on electrolytes and other factors related to blood pressure, found, in within-population analyses involving 10,079 persons, a significant positive association between 24-hour urinary sodium excretion and systolic blood pressure and between the sodium/potassium ratio and systolic blood pressure. These significant findings were derived from analyses for individuals from all 52 centers and from the 48 centers remaining when persons from four low sodium centers were excluded. Potassium excretion of individuals was significantly and independently related inversely to their systolic blood pressure. For men and women, both separate and combined, the relation between sodium and systolic blood pressure was stronger for older than younger adults, perhaps reflecting the result of longer exposure with age or diminished capacity to handle a sodium load. Relations between electrolyte excretion and diastolic blood pressure in individuals were weaker than for systolic blood pressure. Body mass index and heavy alcohol consumption of individuals were strongly and independently related to blood pressure. In cross-population analyses with n = 52 or n = 48, sample median sodium excretion was significantly and independently related to the slope of systolic blood pressure and diastolic blood pressure with age. Other ecological analyses yielded inconsistent results. Four isolated populations showed low sodium excretion, low sodium/potassium excretion, low body mass index, and low alcohol consumption; sample median blood pressures were low, there was little or no upward slope of blood pressure with age, and high blood pressure was rare or nonexistent.

Objectives: To compare blood pressures in northern (Beijing) and southern (Guangzhou) Chinese population samples aged 35-54 years, males and females, urban and rural, and to assess the role of blood pressure-related traits in explaining north-south differences. Design: Cross-sectional surveys were conducted in 1983-1984 of northern and southern populations employed in industry (urban) or farming (rural). Methods: In the north samples were selected from the Capital Iron and Steel Complex (urban) and Shijingshan district (rural); in the south samples from the Guangzhou Shipyard (urban) and Panyu County (rural) were used. Results: The number of subjects surveyed in north and south were 4706 and 4179, respectively: 1500 and 1052 urban males, and 717 and 914 rural males; and 1300 and 1061 urban females, and 1189 and 1152 rural females, respectively

In several large Chicago companies and institutions, workplace screening of 7,151 persons yielded 833 suspect hypertensives. Of these, 91% attended a follow-up verification visit, where for 513 persons high diastolic pressure was confirmed. One-half of these persons were referred to their physicians for treatment and one-half were randomly assigned to be treated directly by HDFP, in a step-wise pharmacologic regimen to normalize diastolic pressure. Of the 257 persons assigned to program treatment, 94% accepted such treatment, and over 90% of these still living in the community were active participants at one year. Average diastolic pressure of these active participants was 83.1 mm Hg at one year, compared to 102.6 at first screen and 98.8 at the second confirmatory screening. A strenuous effort has been made to reduce or eliminate obstacles to treatment, including lack of understanding of the need for long-term therapy, cost barriers and barriers of inconvenience of treatment. The medical team conducting the program combined physicians with nonphysician therapist-health counselors, plus "outreach" staff, to maximize program adherence. Preliminary experiences in the Chicago Center of the Hypertension Detection and Follow-Up Program (HDFP) give encouraging evidence that the workplace is a useful base for successful hypertension control efforts.

SUMMARY The relationship of education to risk factors at baseline and to long-term mortality from coronary heart disease (CHD), cardiovascular diseases (CVD), and all causes was analyzed for three cohorts of middle-aged employed white men in Chicago: 8047 from the Chicago Heart Association Detection Project in Industry (CHA) (entry 1967-1973), 1250 from the Peoples Gas Company Study (PG) (entry 1958-1959) and 1730 from the Western Electric Study (WE) (entry 1957-1958). Each man was classified into one of four groups: not a high school graduate, high school graduate, some college but not a graduate, or college graduate. For all three cohorts, a graded, inverse association was observed at baseline between education and blood pressure, which was statistically significant for CHA and WE men and independent of age and relative weight. For all three cohorts, a significant, graded, inverse association was also recorded between education and cigarette use at entry. For serum cholesterol, no clear pattern was observed for the education groups in any of the three cohorts. CHA men showed a graded, inverse relationship between education and relative weight. This cohort was the only one of three showing a significant, graded inverse association between education and prevalence of ECG abnormalities at entry. For this CHA cohort, 5-year follow-up data showed a statistically significant, graded, inverse relationship between education and ageadjusted mortality rates from CHD, CVD and all causes. With adjustment for entry age, diastolic pressure, cigarettes, serum cholesterol, relative weight and ECG abnormalities, this inverse relationship remainedreduced in degree, but still statistically significant for CVD mortality. Similarly, for the pooled PG-WE cohort of 2980 with 20-21 years of follow-up, education and the three mortality end points were inversely related but not graded, with statistical significance for all three end points in the univariate analyses. The results of these studies indicate inverse relationships between education and lifestyle-related risk factors at baseline and between education and long-term risk of CHD, CVD and all-causes mortality. The inverse relationship between education and mortality is accounted for in part by the established major biomedical risk factors.

Are overnight urine specimens adequate for characterizing the daily salt intake of individuals, i.e., can the overnight specimen replace the 24-hour specimen? Data from 142 male participants of an ongoing trial on the primary prevention of hypertension were used to examine this question with correlation analysis and quantile classification. Estimated correlation between the true mean 24-hour and the true mean overnight sodium excretion was 0.72. Furthermore, 67% of the individuals in the upper third of the distribution of true mean overnight urine sodium were also in the upper third of the distribution of true mean 24-hour sodium. Thus, these data are promising in regard to the use of overnight urine specimens for characterizing the salt intake of individuals. The number of overnight urine collections required to estimate accurately the correlation between an individual's true mean overnight urine sodium and a variable of interest (e.g., blood pressure) was calculated. Given the observed intra- and inter-individual variation, the data indicate that 14 measurements are needed to limit the diminution of the correlation coefficient to 10%.

We compared the effect on serum lipids of an alpha-blocker (prazosin) and a diuretic (hydrochlorothiazide) used as initial antihypertensive drug treatment for 102 men and women with less severe hypertension (average entry blood pressure, 148/97 mm Hg, with no major organ system damage). A two-center trial randomized patients to treatment with either prazosin or hydrochlorothiazide; the alternate drug was added if adequate blood pressure control was not achieved with the originally assigned drug, and patients were removed from any drug they were not able to tolerate. After an average of 40 weeks on the assigned drug regimen, a decline was observed in prazosin-treated patients in both serum total cholesterol (-9.3 mg/dl) and serum triglycerides (-33.9 mg/dl). In contrast, an increase in both these lipids was seen in hydrochlorothiazide-treated patients (+5.0 mg/dl for serum total cholesterol and +18.6 mg/dl for serum triglycerides). The net trial differences between the groups were 14.3 mg/dl for total cholesterol and 52.5 mg/dl for triglycerides, in favor of prazosin (p less than 0.001 for both comparisons). These differences in lipids between the two groups persisted into the second year of the trial (p less than 0.05). There were no significant differences between the drug groups in regard to the level of high density lipoprotein cholesterol or its subfractions or low density lipoprotein cholesterol. In patients who required a combination of the two drugs to achieve blood pressure control, the alpha-blocker diminished or eliminated the lipid-raising effects of the diuretic. Both drugs were similar in their ability to control the elevation of diastolic pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Red blood cell membrane cation transport was measured in five population-based surveys and two randomized, controlled, dietary intervention studies to examine its associations with demographic, biological, and dietary variables in free-living individuals. A total of 508 individuals, 255 with high blood pressure, were studied. Both sexes, blacks and whites, and several age groups were represented. The intervention studies included short-term dietary sodium restriction in normotensive adolescents, and a 4-year multifactorial trial on weight, sodium, and alcohol in hypertensive adults. The findings from these surveys and intervention studies are summarized in this report. Sodium-stimulated lithium countertransport was significantly related to diastolic blood pressure in white adults (r = 0.28, p less than 0.001), and to systolic blood pressure in black children (r = 0.50, p less than 0.005) and white adolescents (r = 0.31, p less than 0.05). Lithium countertransport was related to sex and race, but not age. Body mass index had an independent relationship with lithium countertransport in some age groups. Lithium countertransport was lower in normotensive adults than in both younger and older hypertensive adults. Lithium countertransport did not differ significantly between subjects with hypertension treated with antihypertensive medications and those with untreated hypertension. Short-term dietary sodium restriction did not influence lithium countertransport in normotensive adolescents. Long-term dietary intervention was associated with low lithium countertransport in hypertensive adults able to maintain blood pressure control without medication. These findings indicate that lithium countertransport is related to blood pressure and hypertension among free-living individuals.

Erythrocyte membrane cation transport was measured in 167 adults completing the fourth year of a randomized controlled trial testing the efficacy of nutrition intervention for treatment of 'mild' hypertension. Intervention objectives consisted of weight loss, moderate sodium restriction, and reduction of alcohol intake. The mean sodium-stimulated lithium-countertransport (LCT) for 35 participants able to maintain normotensive blood pressures for 4 years by nutritional means alone was 0.29 mmol/l cells per h compared with 0.38 for the 48 subjects requiring represcription of drugs (P less than 0.01). Weight loss from baseline to year 4 was inversely related to LCT among those who were overweight at baseline (P less than 0.05); reported alcohol intakes were positively related to LCT (P less than 0.05). These findings suggest that blood pressure control by nutrition intervention in 'mild' hypertensives is associated with levels of LCT characteristic of normotension. Higher mean LCT in those requiring represcription of drugs was related to lower serum potassium and higher serum triglyceride levels in this subgroup.