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Biomedical subjects

J Stamler

Publications and source records attributed to J Stamler.

At least 181 records · Page 10Linked to original sources
PubMed1988

A comparison of the random-zero and standard mercury sphygmomanometers.

Both the standard mercury sphygmomanometer and the random-zero sphygmomanometer have been used in epidemiological studies and clinical trials. Problems arise in comparing studies since, in addition to other methodological differences, the readings obtained with the random-zero sphygmomanometer have been found to be lower than those obtained with the standard mercury sphygmomanometer. In the present study, blood pressures were measured in 66 subjects to examine the comparability of findings with the two instruments. Trained observers measured blood pressures simultaneously using a double-headed stethoscope and one cuff connected to the two sphygmomanometers. Use of instrument was randomly assigned for each blood pressure measurement; each observer was unaware of the other's blood pressure reading. Readings were lower with the random-zero sphygmomanometer; mean difference ranged from 2.5 to 3.3 mm Hg for systolic pressure and 1.9 to 2.7 mm Hg for diastolic pressure. Digit distributions recorded by the two observers for the standard mercury sphygmomanometer and the random-zero sphygmomanometer were not significantly different for either systolic or diastolic blood pressure. Intraindividual variation was greater with the random-zero sphygmomanometer than with the standard mercury sphygmomanometer. These data do not indicate that one instrument is clearly superior to the other, although in studies where the observer seeks to reduce the bias of multiple readings per person, the random-zero sphygmomanometer may be the more appropriate instrument. Critical to the use of either instrument are careful training, standardization, certification, and periodic recertification of observers.

Adult↗
PubMed1988

Initial antihypertensive drug therapy. Final report of a randomized, controlled trial comparing alpha-blocker and diuretic.

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)

Adult↗
PubMed1988

Sodium, lithium-countertransport and blood pressure control by nutritional intervention in 'mild' hypertension.

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.

Alcohol Drinking↗
PubMed1988

Dietary cholesterol and human coronary heart disease. The epidemiologic evidence.

For decades, dietary cholesterol has been recognized as the "materia peccans" (Anitschkow) for the induction of atherosclerosis in animals. In rabbits, chickens, and monkeys, long-term feeding of small amounts of cholesterol leads to atherosclerosis despite little or no rise in serum total cholesterol, indicating an independent contribution of dietary cholesterol to atherogenesis over-and-above its influence on serum cholesterol, possibly through effects on serum cholesterol fractions (eg, increased low-density lipoprotein-cholesterol and decreased high-density lipoprotein-cholesterol). In humans, ingestion of dietary cholesterol raises serum cholesterol, largely through its effect on low-density lipoprotein-cholesterol. Over the range of intake in usual American diets, this effect is substantial, eg, with 300 mg of cholesterol intake per 1000 kcal, rather than 100, serum cholesterol is on average about 6% to 7% higher, equivalent to a 12% to 14% greater risk of coronary heart disease (CHD). In international studies based on the Food and Agriculture Organization and the World Health Organization (Geneva) data, mean per capita dietary cholesterol levels are consistently related to CHD mortality rates. In addition, since 1981, four prospective within-population studies have shown that dietary cholesterol intake of individuals is significantly related to their long-term CHD risk, independent of and in addition to serum cholesterol, blood pressure, and cigarette use. On average, a 200-mg/1000 kcal higher intake of cholesterol at baseline was associated with a 30% higher CHD rate (95% confidence interval, 1.1 to 1.5). Conversely, lower intakes of cholesterol were associated with significantly lower risks of CHD, and of all causes mortality as well. For example, with 19 years of follow-up in the Chicago Western Electric Study, a 200-mg/1000 kcal habitual lower cholesterol intake was associated with a 37% lower risk of death from any cause, equivalent to a life expectancy longer by 3.4 years. The importance of a low-dietary cholesterol intake for prevention of CHD merits increased emphasis.

Animals↗
PubMed1988

Circadian rhythm with acrophase at night for urinary excretion of calcium and magnesium in childhood: population-based data of the cimitile study in southern Italy.

A population-based study on daily and overnight urine excretion of Ca and Mg was performed in 220 children aged 4-15 years living in Cimitile, Campania Region, Southern Italy. The Ca/creatinine and the Mg/creatinine ratio in overnight urine were significantly higher than in daily urine (p less than 0.01). This finding was also confirmed in hypercalciuric children. The Mg/Ca ratio in the general population was identical in daily and overnight urine while in the hypercalciuric group Mg/Ca in overnight urine was significantly higher (p less than 0.01) than in daily urine. The data point to the existence of a circadian rhythm with a peak at night for urine Ca and Mg excretion in children living in Cimitile and studied while attending to their everyday life.

Adolescent↗
PubMed1987

Background and design of the new U.S. trial on diet and drug treatment of "mild" hypertension (TOMHS).

A multicenter, randomized, controlled, double-blind U.S. trial is comparing the combined effects of diet treatment and 1 of 5 active drug regimens with diet treatment alone, for the long-term management of middle-aged adults with "mild" hypertension. Factors stimulating this trial are data documenting the high prevalence of mild hypertension in the adult population; mild hypertension's responsibility for a high proportion of morbidity and mortality attributable to hypertension overall; data from long-term hypertension intervention trials showing reduced morbidity and mortality of people with mild hypertension with use of either diuretics or beta blockers as step-1 therapy, and other trials that failed to demonstrate beneficial impact on morbidity and mortality, possibly due to residual questions concerning aspects of benefit to risk ratios with these medications; recent data from trials showing long-term control of mild hypertension and other risk factors by nutritional means; lack of data from long-term trials on benefit to risk ratios with newer drugs such as selective alpha 1 inhibitors, angiotensin converting enzyme inhibitors and calcium channel blockers; paucity of data from trials on long-term combined effects of diet and drug therapy, and of diet alone, for people with mild hypertension. During the next few years, phase 1 of the trial will study 6 groups of drugs. The step-1 drugs are angiotensin converting enzyme inhibitor (enalapril), alpha 1 inhibitor (doxazosin), beta blocker (acebutolol), calcium channel blocker (amlodipine), diuretic (chlorthalidone) and placebo. All participants are to receive vigorous sustained nutritional counseling to reduce obesity, moderate sodium intake and avoid heavy use of alcohol. Key endpoints for phase 1 of the study are the need for additional medication to control mild hypertension, side effects (i.e., clinical and biochemical) and consequent need to discontinue drug and quality of life. Phase-1 data are to be used to complete the phase-2 design, with the ultimate aim to assess effects on morbidity and mortality.

Adult↗
PubMed1987

Nutritional therapy for high blood pressure. Final report of a four-year randomized controlled trial--the Hypertension Control Program.

A four-year trial assessed whether less severe hypertensives could discontinue antihypertensive drug therapy, using nutritional means to control blood pressure. Randomization was to three groups: group 1--discontinue drug therapy and reduce overweight, excess salt, and alcohol; group 2--discontinue drug therapy, with no nutritional program; or group 3--continue drug therapy, with no nutritional program. In groups 1 and 2 patients resumed drug therapy if pressure rose to hypertensive levels. Loss of at least 4.5 kg (10 + lb) was maintained by 30% of group 1, with a group mean loss of 1.8 kg (4 lb); sodium intake fell 36% and modest alcohol intake reduction was reported. At four years, 39% in group 1 remained normotensive without drug therapy, compared with 5% in group 2. Study findings demonstrated that nutritional therapy may substitute for drugs in a sizable proportion of hypertensives or, if drugs are still needed, can lessen some unwanted biochemical effects of drug treatment.

Adult↗
PubMed1987

Serum cholesterol levels and cancer mortality in 361,662 men screened for the Multiple Risk Factor Intervention Trial.

Several prospective studies have demonstrated an association between low serum cholesterol level and subsequent mortality from cancer. This finding was explored in the large cohort (361,662) of men aged 35 to 57 years who were screened for possible randomization to the Multiple Risk Factor Intervention Trial. Mortality follow-up revealed a significant excess of cancer in the lowest decile of serum cholesterol level during the early years of follow-up, which attenuated over time. In contrast, the association between high serum cholesterol and coronary heart disease did not diminish during the average of seven years of follow-up. These findings are consistent with the inference that the association between low serum cholesterol level and cancer is at least in part due to an effect of preclinical cancer on serum cholesterol level. A subset of the cohort (12,866 men) participated in the randomized Multiple Risk Factor Intervention Trial protocol, which called for annual measurements of serum cholesterol level. Among the 150 of these men who died of cancer during the trial, cholesterol level fell 22.7 mg/dL (0.59 mmol/L) more than in the survivors over an equivalent period. These data are consistent with the foregoing inference.

Adult↗
PubMed1987

The role of relative weight in the positive association between age and serum cholesterol in men and women.

With advancing age from youth on, there is an increase in mean serum cholesterol level of populations in "western" industrialized countries. Since serum cholesterol is one of the established major risk factors for premature coronary heart disease, it is important to explore the degree to which this age trend is physiologic or due to modern life styles. This study used cross-sectional data for 19,730 white men and 13,872 white women from the Chicago Heart Association Detection Project in Industry to investigate one aspect of this question: does weight explain the association between age and serum cholesterol, in particular whether older age is associated with higher serum cholesterol in the absence of overweight. The relationships among age, relative weight, and serum cholesterol were examined through assessment of mean serum cholesterol levels in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, 55-64) and by relative weight (less than 100, 100-109, 110-119, 120-134, greater than or equal to 135). Age and serum cholesterol were positively associated with each other. In women, it was a simple, linear relationship. In men, the degree of this positive association was less in people over age 35-44 than people in younger ages. These age-cholesterol patterns were present in men and women at desirable weight. However, in men aged 18-54, the positive association between age and prevalence of marked hypercholesterolemia (serum cholesterol greater than or equal to 250) was lower in people at desirable relative weight in comparison to those at higher relative weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Coffee consumption and mortality in the Chicago Western Electric Company Study.

The relations between coffee consumption and 19-year mortality from all causes, coronary heart disease, and non-coronary causes were assessed in 1,910 white males aged 40-56 years in 1957-1958 from the Chicago Western Electric Company Study. Mortality rates, adjusted for age, serum cholesterol, diastolic blood pressure, and smoking status, were compared for those consuming 0-1, 2-3, 4-5, and 6+ cups of coffee per day; coffee intake, measured at the first anniversary examination, included both caffeinated and decaffeinated intake. Mortality from all causes was greatest in the highest and lowest intake groups. The increased mortality in the 6+ cups per day group was due to coronary heart disease, while the increased mortality in the lowest intake group was due to noncoronary causes. The adjusted relative risk of coronary heart disease death for those drinking 6+ cups of coffee per day compared with those drinking less was 1.71 (95 per cent confidence limits 1.27, 2.30). This increased risk of coronary heart disease death was present in both smokers and nonsmokers, with adjusted relative risks of 1.62 and 2.21, respectively (95 per cent confidence limits 1.17, 2.24 and 1.06, 4.62). The increased mortality from non-coronary causes in the lowest intake group was due primarily to increased mortality from cancer and cardiovascular diseases other than coronary heart disease. The results of this study support the hypothesis that those who drink 6+ cups of coffee per day may be at an increased risk of death from coronary heart disease.

Adult↗
PubMed1987

Cardiovascular responses to exercise of participants in a trial on the primary prevention of hypertension.

The Chicago study on the Primary Prevention of Hypertension (PPH) is a long-term, randomized controlled trial to test the ability of nutritional-hygienic non-pharmacological methods to prevent high blood pressure in hypertension-prone persons aged 30-44 years at entry. In order to assess the effects of this programme on cardiovascular responses to exercise, graded submaximal treadmill exercise tests were done serially at baseline and during the trial. Eighty-five participants (48 intervention, 37 control) successfully finished baseline and 2- or 3-year follow-up tests. The exercise maximal double product (DP) [systolic blood pressure (SBP) X heart rate/100] was significantly lower for both groups at 2-3 years compared with baseline, and this reduction was greater for the intervention than for the control group (-27.1 versus -15.5; P = 0.055). Similarly, improvement in maximal increase in DP (maximal DP minus standing DP) was greater for the intervention than the control group (-22.1 versus -9.9, respectively; P = 0.068). The lowest DP during the 6-min recovery period and the debt DP (lowest recovery DP minus standing DP) fell significantly at 2-3 years compared with baseline in the intervention but not in the control group (-12.7 versus -4.8; P = 0.017 for the first index, and -7.7 versus +0.9; P = 0.029 for the second). These interim data from this trial indicate that its intervention procedures favourably influenced cardiovascular responses to graded submaximal exercise.

Adult↗
PubMed1987

Variability of urinary sodium and potassium excretion in north Chinese men.

Variability of urine sodium (Na), potassium (K) and sodium/potassium (Na/K) excretion was studied in a sample of 50 employed normotensive male health professionals aged 27-50 in Beijing, China. Six 24-h urine specimens were collected from each participant during night-time (12-h) and daytime (12-h) fractions. The estimated ratio of intra- to inter-individual variances was 2.12 for night-time and 1.48 for 24-h urine Na, and 1.85 and 1.54, respectively, for urine K. Based on these values, six night-time and four 24-h urine specimens are necessary to reduce to 15% the diminution of a correlation between urine Na and another physiological variable. The corresponding numbers are five and four, respectively, for urinary K measurement. These data suggest that the ratio of within-person variation to between-person variation in Na excretion is smaller in these Chinese men than in Americans. The dietary Na intake of Chinese men can therefore be characterized with fewer urine specimens than are required for western populations. Night-time urinary Na and K showed good concordance with those from 24-h specimens in distinguishing high or low Na and K intake. These findings indicate that in large-scale epidemiological studies, overnight specimens may be adequate for classifying individuals with regard to Na and K intake.

Adult↗
PubMed1987

Sex differential in the relationship of electrocardiographic ST-T abnormalities to risk of coronary death: 11.5 year follow-up findings of the Chicago Heart Association Detection Project in Industry.

The independent contributions of ST segment depression and/or T wave abnormality (ST-T abnormalities) on the baseline resting electrocardiogram to risk of 11.5 year coronary heart disease (CHD) mortality were explored among 9203 white men and 7818 white women who were 40 to 64 years old and without definite CHD at entry in the Chicago Heart Association Detection Project in Industry. At baseline, prevalence rates of ST-T abnormalities were age related for both sexes, and at every age the rate was higher in women than men (age-adjusted prevalence rates 12.3% and 8.1%, respectively). Univariate analysis showed that ST-T abnormalities were associated with significantly increased risk of death from CHD for both men and women. However, men with ST-T abnormalities had much greater age-adjusted and multiple risk factor-adjusted absolute excess risk and relative risk than women with such electrocardiographic abnormalities. When baseline age, diastolic pressure, serum cholesterol, cigarettes/day, history of diabetes, and baseline use of antihypertensive medication were included in the multivariate analysis, ST-T abnormalities remained significantly related to death from CHD in men but not women. The interaction term between sex and ST-T abnormalities was at a borderline level of statistical significance by Cox regression analysis. In conclusion, ST-T abnormalities indicate an increased risk of subsequent death from CHD independent of major coronary risk factors for middle-aged U.S. men, but this is not clearly so for women.

Adult↗
PubMed1987

Do hypertensive patients have a different diurnal pattern of electrolyte excretion?

Studies generally indicate that excretion of sodium, potassium, and water is greater during the day than during the night. To determine whether hypertensive patients exhibit this same pattern of excretion, diurnal variations in excretion of sodium, potassium, creatinine, and water were examined in 107 hypertensive men and women from a clinical trial on control of hypertension by nonpharmacological means--the Hypertension Control Program. Each participant provided two carefully timed 24-hour urine collections divided into daytime and overnight specimens. The median ratios of 24-hour to 8-hour overnight excretion were 2.84, 3.95, 2.99, and 2.77 for sodium, potassium, creatinine, and water, respectively. Thus, more than half of this hypertensive group exhibited a greater rate of sodium and water excretion during sleep than during daytime hours, a reversal of the usual pattern. When the group was subdivided based on age, sex, race, trial randomization group, use of diuretics, and hypertension severity, women had significantly lower ratios of 24-hour to overnight excretion for sodium and water than men and blacks had significantly lower 24-hour to overnight ratios for water and potassium than whites. When the 24-hour to overnight ratios for these hypertensive patients were compared with those for a group of 30 men and women with high-normal blood pressure, those with high-normal blood pressure had significantly larger ratios for sodium and water excretion than the hypertensive group. The results of this study suggest that hypertensive patients may have a different diurnal pattern of sodium and water excretion than normotensive subjects and that further research is needed to clarify this issue.

Adult↗
PubMed1987

Epidemiological studies of sodium transport and hypertension.

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.

Adolescent↗