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N O Borhani

Publications and source records attributed to N O Borhani.

At least 19 recordsLinked to original sources
PubMed1992

Isolated systolic hypertension and subclinical cardiovascular disease in the elderly. Initial findings from the Cardiovascular Health Study.

OBJECTIVE: To assess the association between isolated systolic hypertension (ISH) and subclinical disease in adults aged 65 years and above. DESIGN: Medicare eligibility lists were used to obtain a representative sample of 5201 community-dwelling elderly persons for the Cardiovascular Health Study, a National Heart, Lung, and Blood Institute--sponsored cohort study of risk factors for coronary heart disease and stroke. In this cross-sectional analysis of baseline data, we excluded 3012 participants who were receiving antihypertensive medications, had clinical cardiovascular disease, or had a diastolic blood pressure of at least 90 mm Hg. MAIN OUTCOME MEASURES: For electrocardiogram: myocardial infarction, left ventricular hypertrophy, and left ventricular mass as measures of myocardial damage and strain; for echocardiography: left ventricular mass, fractional shortening, and Doppler flow velocities as measures of cardiac systolic and diastolic function; and for carotid sonography: carotid arterial intima-media thickness as a measure of atherosclerosis. RESULTS: Among the 2189 men and women in this analysis, 195 (9%) had ISH (systolic blood pressure, greater than or equal to 160 mm Hg) and 596 (23%) had borderline ISH (systolic blood pressure, 140 to 159 mm Hg). Systolic blood pressure was associated with myocardial infarction by electrocardiogram (P = .02). Borderline and definite ISH were strongly associated with left ventricular mass (P less than .001). While there was little association with cardiac systolic function, borderline and definite ISH were associated with cardiac diastolic function (P less than .001). Isolated systolic hypertension was also strongly associated with increased intima-media thickness of the carotid artery (P less than .001). CONCLUSIONS: While cohort analyses of future repeated measures will provide a better assessment of risk, both borderline and definite ISH were strongly related to a variety of measures of subclinical disease in elderly men and women.

Aged↗
PubMed1992

Major electrocardiographic abnormalities in persons aged 65 years and older (the Cardiovascular Health Study). Cardiovascular Health Study Collaborative Research Group.

Electrocardiographic abnormalities are often found in older patients, but their prevalence in free-living elderly populations is not well-defined. In addition, the clinical significance of many of these abnormalities is uncertain. The prevalence of major electrocardiographic abnormalities was determined in 5,150 adults aged greater than or equal to 65 years from the Cardiovascular Health Study--a study of risk factors for stroke and coronary heart disease in the elderly. Ventricular conduction defects, major Q/QS waves, left ventricular hypertrophy, isolated major ST-T-wave abnormalities, atrial fibrillation and first-degree atrioventricular block were collectively categorized as major electrocardiographic abnormalities. Prevalence of any major electrocardiographic abnormality was 29% in the entire cohort, 19% among 2,413 participants who reported no history of coronary artery disease or systemic hypertension, and 37% among 2,737 participants with a history of coronary artery disease or hypertension. Prevalence of major electrocardiographic abnormalities was higher in men than in women regardless of history, and tended to increase with age. Major Q/QS waves were found in 5.2%, and more than half were in those who did not report a previous myocardial infarction. Major electrocardiographic abnormalities are common in elderly men and women irrespective of the history of heart disease.

Age Factors↗
PubMed1992

Eligibility for cholesterol referral in community-dwelling older adults. The Cardiovascular Health Study.

OBJECTIVES: To assess the proportion of community-dwelling adults aged 65 years or older who are eligible for referral for lipoprotein analysis and intervention according to the National Cholesterol Education Program (NCEP) guidelines. DESIGN: Cross-sectional study based on examinations and questionnaires collected in 1989 and 1990. SETTING: Four communities in the U.S. in the Cardiovascular Health Study (CHS), a study of risk factors for heart disease and stroke in older adults. PARTICIPANTS: A sample of 4810 men and women ages 65 to 100 randomly selected and recruited from Health Care Financing Administration Medicare eligibility lists for the four communities; not institutionalized, not wheelchair-bound, not currently receiving therapy for cancer, not currently taking lipid-lowering medications, and not having eaten in the preceding 9 hours. MEASUREMENTS: Total cholesterol and lipoprotein analysis measured in all participants. RESULTS: Total cholesterol levels were less than 5.17 mmol/L (200 mg/dL) in 37% of participants, 5.17 to 6.19 mmol/L (200 to 239 mg/dL) in 39%, and 6.20 mmol/L (240 mg/dL) or greater in 24%. Compared with their counterparts, older participants, especially those over 80 years of age, were more likely to have levels below 5.17 mmol/L, as were men, nonwhites, and those with coronary heart disease or two or more coronary heart disease risk factors (P less than 0.008 for all values). Based on this screening measurement, 2174 participants were eligible for lipoprotein analysis, 80% were eligible for dietary or drug therapy using NCEP guidelines. Overall, 46% of CHS participants were eligible for lipoprotein analysis and 36% for intervention by NCEP guidelines, based on a single cholesterol measurement. CONCLUSION: A substantial proportion of older adults in this community sample were eligible for lipoprotein analysis and intervention. Prospective studies of elderly persons are needed to determine the risk for incident coronary heart disease according to NCEP classifications and the benefits of lipid-lowering treatments in persons in this age group so that intervention strategies may best be targeted to an appropriately high-risk group.

Age Factors↗
PubMed1992

Baseline characteristics of participants in phase I of the Trials of Hypertension Prevention.

Phase I of the Trials of Hypertension Prevention was designed to test the effectiveness and safety of three life-style (weight loss, sodium restriction, and stress management) and four nutrition supplement (calcium, magnesium, potassium, and fish oil) interventions in reducing diastolic blood pressure (DBP) in persons with a high-normal blood pressure. A total of 2182 persons with a DBP between 80 and 89 mm Hg met the eligibility criteria for participation in phase I and were randomized to one of the active intervention or control treatment groups. Most were white (82%), male (70%), married (76%), nonsmoking (88%), college graduate (53%), full-time employees (91%). The average blood pressure prior to entry into the trial was 124.9 mm Hg systolic and 83.8 mm Hg diastolic. A variety of baseline observations, including sociodemographic characteristics, personal and family medical history, health habits, diet, and biologic measurements, were documented before randomization and compared among the seven active intervention and control groups. As might be expected in a randomized trial of this sample size, the distribution of measured baseline characteristics was virtually identical in the treated and control groups. Based on this finding and the knowledge that randomization procedures were implemented without deviation from the phase I protocol, it is probable that unknown potential confounders were also equally distributed at entry into the study. Given the achievement of high rates of follow-up, subsequent differences in blood pressure are unlikely to have been due to baseline differences between the active treatment and control groups, and can probably be attributed to effects of the active interventions.

Adult↗
PubMed1992

Lipoprotein lipids in older people. Results from the Cardiovascular Health Study. The CHS Collaborative Research Group.

BACKGROUND: Cardiovascular disease is the leading cause of death and disability in older people. There is little information about the distributions of risk factors in older populations. This article describes the distribution and correlates of lipoprotein lipids in people greater than or equal to 65 years old. METHODS AND RESULTS: Lipoprotein lipid concentrations were measured in 2,106 men (M) and 2,732 women (F) who were participants in the Cardiovascular Health Study, a population-based epidemiological study. Distributions of lipids by age and sex and bivariate and multivariate relations among lipids and other variables were determined in cross-sectional analyses. Mean concentrations of lipids were cholesterol: M, 5.20 +/- 0.93 mmol/l (201 +/- 36 mg/dl) and F, 5.81 +/- 0.98 mmol/l (225 +/- 38 mg/dl); triglyceride (TG): M, 1.58 +/- 0.85 mmol/l (140 +/- 75 mg/dl) and F, 1.57 +/- 0.78 mmol/l (139 +/- 69 mg/dl); high density lipoprotein cholesterol (HDL-C): M, 1.23 +/- 0.33 mmol/l (48 +/- 16 mg/dl), and F, 1.53 +/- 0.41 mmol/l (59 +/- 16 mg/dl); low density lipoprotein cholesterol (LDL-C): M, 3.27 +/- 0.85 mmol/l (127 +/- 33 mg/dl) and F, 3.57 +/- 0.93 mmol/l (138 +/- 36 mg/dl). The total cholesterol to HDL-C ratios were M, 4.49 +/- 1.29 and F, 4.05 +/- 1.22. TG, total cholesterol, and LDL-C concentrations were lower with increasing age, the last more evident in men than in women. TG concentration was positively associated with obesity (in women), central fat patterning, glucose intolerance, use of beta-blockers (in men), and use of estrogens (in women) and negatively associated with age, renal function, alcohol use, and socioeconomic status. In general, HDL-C had opposite relations with these variables, except that estrogen use was associated with higher HDL-C concentrations. LDL-C concentration was associated with far fewer variables than the other lipids but was negatively associated with age in men and women and positively correlated with obesity and central fat patterning and negatively correlated with renal function and estrogen use in women. There were no differences in total cholesterol and LDL-C concentrations among participants with and without prevalent coronary heart disease and stroke, but TG concentration was higher and HDL-C lower in men with both coronary heart disease and stroke and in women with coronary heart disease. CONCLUSIONS: Cholesterol and cholesterol/HDL-C ratio were lower and HDL-C higher than previously reported values in older people, suggesting that lipid risk profiles may be improving in older Americans. TG and HDL-C concentrations, and to a lesser extent LDL-C, were associated with potentially important modifiable factors such as obesity, glucose intolerance, renal function, and medication use.

Aged↗
PubMed1992

MIDAS: hypertension and atherosclerosis. A trial of the effects of antihypertensive drug treatment on atherosclerosis. MIDAS Research Group.

Although clinical trials of the efficacy of antihypertensive treatment have demonstrated impressive reductions in the incidence of stroke, the reduction in coronary artery disease mortality has been less impressive. It may be that the antihypertensive drugs used in these trials induced metabolic disturbances, or produced inadequate regression of left ventricular hypertrophy, thus blunting the reduction in risk of coronary artery disease expected with blood pressure-lowering. Isradipine, a dihydropyridine calcium antagonist known to be an effective antihypertensive agent, has also displayed pronounced antiatherogenic effects in animals. Thus, a reasonable hypothesis could be that isradipine not only reduces the level of blood pressure, but also may have a positive effect on the evolution of atherosclerotic plaque in coronary and carotid arteries, thereby leading to prevention of clinical sequelae of atherosclerosis. On this basis, a 3-year clinical trial is being carried out in the United States--the Multicenter Isradipine/Diuretic Atherosclerosis Study (MIDAS)--to establish the efficacy of isradipine in inhibiting atherogenesis and retarding the progression of atherosclerosis in carotid arteries of hypertensive patients. The primary end point of the study is intima-media thickness and the extent of atherosclerotic plaque in the carotid arteries, as measured by B-mode ultrasonography.

Antihypertensive Agents↗
PubMed1991

The Hypertension Prevention Trial: assessment of the quality of blood pressure measurements.

Blood pressure variability is an important consideration in hypertension trials for determining required sample size and consequently making accurate outcome statements. The Hypertension Prevention Trial was a randomized controlled trial carried out in 1983-1986 in four US clinics on men and women with high normal diastolic blood pressure. This trial provided an opportunity to assess conditions affecting blood pressure measurement variability. Trained blood pressure observers measured systolic and diastolic blood pressures twice, 30 seconds apart, using a random-zero sphygmomanometer. The quality of blood pressure measurements was assessed by computing the variability of the two readings per participant-visit for each blood pressure observer at each study clinic. Other sources of variability investigated included observer digit preference, time of day, and ambient temperature. On the basis of data from this population, it is estimated that the standard deviation of blood pressure values can be reduced by 5% by taking two measurements per participant-visit. An additional reduction of variability can be effected by having the duplicate blood pressure measurements made by different blood pressure observers. In special instances where the range of blood pressure values is very restricted, use of the random-zero sphygmomanometer can increase or decrease the among-participant variability in blood pressure values, depending upon where the distribution of blood pressure values is centered.

Adult↗
PubMed1991

The Cardiovascular Health Study: design and rationale.

The Cardiovascular Health Study (CHS) is a population-based, longitudinal study of coronary heart disease and stroke in adults aged 65 years and older. The main objective of the study is to identify factors related to the onset and course of coronary heart disease and stroke. CHS is designed to determine the importance of conventional cardiovascular disease (CVD) risk factors in older adults, and to identify new risk factors in this age group, especially those that may be protective and modifiable. The study design called for enrollment of 1250 men and women in each of four communities: Forsyth County, North Carolina; Sacramento County, California; Washington County, Maryland; and Pittsburgh, Pennsylvania. Eligible participants were sampled from Medicare eligibility lists in each area. Extensive physical and laboratory evaluations were performed at baseline to identify the presence and severity of CVD risk factors such as hypertension, hypercholesterolemia and glucose intolerance; subclinical disease such as carotid artery atherosclerosis, left ventricular enlargement, and transient ischemia; and clinically overt CVD. These examinations in CHS permit evaluation of CVD risk factors in older adults, particularly in groups previously under-represented in epidemiologic studies, such as women and the very old. The first of two examination cycles began in June 1989. A second comprehensive examination will be repeated three years later. Periodic interim contacts are scheduled to ascertain and verify the incidence of CVD events, the frequency of recurrent events, and the sequellae of CVD.

Aged↗
PubMed1991

Trials of hypertension prevention. Phase I design.

Phase I of the Trials of Hypertension Prevention (TOHP) was a National Heart, Lung, and Blood Institute-sponsored, 3-year, national, multicenter, randomized, controlled trial designed to test the feasibility and efficacy of three life-style (weight loss, sodium restriction, and stress management) and four nutrition supplement (calcium, magnesium, fish oil, and potassium) interventions aimed at lowering diastolic blood pressure in those whose blood pressure was initially in the high normal range (80 to 89 mm Hg). A total of 2182 volunteers were recruited and allocated to the various treatment arms, such that each hypothesis was tested with a power of 85% or higher to detect a diastolic blood pressure treatment effect of 2 mm Hg. The four nutrition supplement interventions were delivered in a double-blinded fashion and the three life-style interventions, single (observed) -blinded. Phase I was designed to provide a rigorous test of short-term lowering of blood pressure for each of the seven treatments chosen and provides the basis for planning of a subsequent long-term trial of hypertension prevention.

Adult↗
PubMed1991

The Multicenter Isradipine/Diuretic Atherosclerosis Study: a study of the antiatherogenic properties of isradipine in hypertensive patients. MIDAS Research Group.

Hypertension is a risk factor for the development of atherosclerosis and its complications, which are among the major causes of morbidity and mortality. Although recent clinical trials indicate that antihypertensive treatment reduces morbidity and mortality associated with stroke, congestive heart failure, and renal insufficiency, questions remain as to whether such treatment also prevents coronary heart disease (CHD) mortality. The observed reduction in CHD mortality from pooled clinical trial data was 10-14% and was much less than the expected 20-25% reduction for a 5-6 mm Hg reduction in diastolic pressure. One explanation may be that subtle adverse metabolic effects of treatment may have blunted the beneficial effects. Isradipine, a dihydropyridine calcium antagonist, is a potent antihypertensive drug with antiatherogenic properties in animal models. Therefore, we hypothesized that isradipine may be appropriate for testing the efficacy of antihypertensive treatment in retarding the progression of atherosclerosis in humans. The Multicenter Isradipine/Diuretic Atherosclerosis Study (MIDAS) is a clinical trial designed to compare the efficacy of isradipine (2.5 or 5 mg b.i.d.) with hydrochlorothiazide (12.5 or 25 mg b.i.d.) in retarding the progression of early carotid atherosclerosis as monitored by high-resolution B-mode ultrasonography.

Adult↗
PubMed1990

Dietary protein and blood pressure in monozygotic twins.

Cross-sectional studies relating blood pressure to dietary intake have shown equivocal results, in part due to the inability to take into account the strong genetic component of blood pressure. Intervention studies, using the same subject as his own control, often encounter additional problems when subjects are asked to adhere to an alternate diet. The National Heart, Lung, and Blood Institute Twin Study of middle-aged men provided information concerning the possible relationship of food-frequency-estimated nutrient intake to blood pressure while controlling for genetic effects in a free-living group of subjects. Using differences in monozygotic twins, a direct association of dietary protein intake and diastolic blood pressure was identified and persisted after adjustment for known covariates of blood pressure. Adjusting for known covariates and holding total calories constant, a 9-g difference in daily protein intake was directly associated with a 1 mm Hg difference in diastolic blood pressure. For protein intake as a percentage of total calories, a 2.18% difference was directly associated with a 1 mm Hg difference in diastolic blood pressure. The co-twin-control method provides a powerful design to address the interrelationships between nutrients and blood pressure in an observational as well as an experimental setting.

Adult↗
PubMed1990

Validation of reported myocardial infarction mortality in blacks and whites. A report from the Community Cardiovascular Surveillance Program.

It is widely believed that blacks experience a higher mortality due to coronary heart disease (CHD) than do whites. To determine whether this reported difference in mortality between blacks and whites is real, we studied the question in the context of the Community Cardiovascular Surveillance Program (CCSP). Fatal and nonfatal cases of CHD were reviewed in 12 US communities. Standardized criteria were applied to classify these cases as possible CHD, definite CHD, possible myocardial infarction (MI), or definite MI. The annual age-adjusted mortality rate per 100,000 ascribed to definite MI by the CCSP criteria was higher in blacks than in whites: 47 in white men (95% confidence interval, 36 to 58), 18 in white women (95% confidence interval, 8 to 28), 95 in black men (95% confidence interval, 10 to 180), and 41 for black women (95% confidence interval, 0 to 99). The proportion of definite MI to all fatal CHD events was higher in blacks (16%) than in whites (12%). For nonfatal events, however, the rate of definite MI was higher in whites than in blacks: 322 in white men (95% confidence interval, 293 to 351), 225 in black men (95% confidence interval, 160 to 290), 82 in black women (95% confidence interval, 43 to 121), and 103 in white women (95% confidence interval, 88 to 118). The proportion of definite MI to all nonfatal CHD events was lower in blacks (16%) than in whites (30%). Thus, the overall rate for fatal and nonfatal definite MI was lower in blacks (215/100,000) than in whites (244/100,000). These observations suggest that a combination of high case-fatality ratio and misclassification of cause and death may contribute to the reported higher rate of CHD mortality among blacks.

Adult↗
PubMed1990

Multicenter study with isradipine and diuretics against atherosclerosis. US MIDAS Research Group.

Hypertension is a major risk factor for atherosclerosis. Although antihypertensive drug treatment can reduce morbidity and mortality from stroke, there is no consistent benefit on ischemic heart disease. It may be that subtle adverse effects of the drugs used in these clinical trials may have blunted the beneficial effects of treatment. Isradipine, a new calcium antagonist of the dihydropyridine class, is a potent antihypertensive drug with pronounced antiatherogenic properties, at least in animal studies. Thus, isradipine may be a suitable drug for assessing the efficacy of antihypertensive treatment in retarding the progression of atherosclerosis. The Multicenter Isradipine/Diuretic Atherosclerosis Study (MIDAS) is a clinical trial to compare the efficacy of isradipine (2.5-5.0 mg b.i.d.) and hydrochlorothiazide (12.5-25 mg b.i.d.) in retarding atherosclerosis in carotid arteries. Carotid atherosclerosis will be monitored using B-mode ultrasonography. The sample size is 800 men and women aged 40 years and over. The power of the design is 90% to detect a 30% difference in the progression of plaque size between the isradipine- and hydrochlorothiazide-treated groups with a significance level of 5% (p = 0.05).

Arteriosclerosis↗
PubMed1989

How to manage other risk factors in patients with hypertension.

High blood pressure is unquestionably a risk factor for premature morbidity and mortality, especially from coronary artery disease and stroke. Risk of clinical manifestations of coronary artery disease increases dramatically if other risk factors, such as a history of cigarette smoking, hypercholesterolemia, left ventricular hypertrophy, and diabetes, are present in addition to hypertension. Therefore, management must include measures to control these risk factors as well as reduce blood pressure. In patients with hypercholesterolemia or diabetes, some antihypertensive drugs must be used with extreme caution or avoided altogether because of possible side effects. Although systolic pressure is an important prognostic factor, there is currently no evidence that treatment of isolated systolic hypertension is beneficial.

Antihypertensive Agents↗
PubMed1989

Design, methods, and rationale in the Hypertension Prevention Trial. Hypertension Prevention Trial Research Group.

The Hypertension Prevention Trial (HPT) was a randomized, controlled, multicenter (four clinics, four resource centers) trial designed to test the feasibility of achieving and sustaining dietary changes in the intake of calories, sodium, and potassium and to assess the effect of those changes on blood pressure in a normotensive population. The trial involved 841 men and women (plus a test cohort of 78) who, at the first baseline (BL) examination, were in the age range of 25-49 years and had diastolic blood pressure (DBP) greater than or equal to 76 but less than 100 mm Hg (average of two readings), and at the examination prior to randomization (BL 2) had DBP greater than or equal to 78 but less than 90 mm Hg (also averaged). Participants were randomly assigned to a control treatment group (no dietary counseling) or to one of four dietary treatment groups involving counseling designed to reduce calorie intake, reduce sodium intake, reduce sodium and calorie intake, and reduce sodium and increase potassium intake. Dietary counseling was provided primarily in group settings and was aimed at changing participants' shopping, cooking, and eating habits related to a designated treatment assignment. The effect of dietary counseling was measured through changes in urinary excretion of sodium and potassium, changes in body weight, and changes in reported food intake based on 24-hour food records. Blood pressure changes during the 3-year course of followup were based on measurements taken at 6-month intervals from enrollment using a random-zero sphygmomanometer. This chapter provides a general description of the design and methods of the HPT and the underlying rationale for decisions affecting the design.

Adult↗