RESUMEN

Cardiovascular mortality in dialysis patients remains a serious problem. It is 10 to 20 times higher than in the general population. No molecular mechanism has been proven to explain this increased mortality, although nitric oxide (NO) has been implicated. The objective of our study was to determine the extent of the removal of the NO congeners nitrite and nitrate from plasma and saliva by hemodialysis, as this might disrupt physiological NO bioactivity and help explain the health disparity in dialysis patients. Blood and saliva were collected at baseline from patients on dialysis and blood was collected as it exited the dialysis unit. Blood and saliva were again collected after 4-5h of dialysis. In the 27 patients on dialysis, baseline plasma nitrite and nitrate by HPLC were 0.21±0.03 and 67.25±14.68 µM, respectively. Blood immediately upon exit from the dialysis unit had 57% less nitrite (0.09±0.03 µM; P=0.0008) and 84% less nitrate (11.04 µM; P=0.0003). After 4-5h of dialysis, new steady-state plasma levels of nitrite and nitrate were significantly lower than baseline, 0.09±0.01 µM (P=0.0002) and 16.72±2.27 µM (P=0.001), respectively. Dialysis also resulted in a significant reduction in salivary nitrite (232.58±75.65 to 25.77±10.88 µM; P=0.01) and nitrate (500.36±154.89 to 95.08±24.64 µM; P=0.01). Chronic and persistent depletion of plasma and salivary nitrite and nitrate probably reduces NO bioavailability and may explain in part the increased cardiovascular mortality in the dialysis patient.

Asunto(s)

RESUMEN

Peripartum cardiomyopathy is an unusual and uncommon form of dilated cardiomyopathy that is often fatal to young women. Fetal outcome, however, is quite good. The disease occurs in 250-1350 women each year in the United States. Myocarditis of viral, immunologic, or idiopathic etiology has been suggested. Diagnostic findings are consistent with congestive heart failure. Primary therapy consists of bed rest, sodium and fluid restriction, vasodilators, digoxin, and diuretics. Refractory cases can be treated with cardiac transplantation. Selected patients require anticoagulation. Prognosis depends on 6-month recovery of left ventricular function. It is important to emphasize that functional recovery does not denote total recovery of cardiac function; this is critical in terms of future pregnancies. This article presents the case of a young woman with peripartum cardiomyopathy and a review of the literature. (c)2001 by CHF, Inc.

RESUMEN

CONTEXT: Heart failure is often preceded by isolated systolic hypertension, but the effectiveness of antihypertensive treatment in preventing heart failure is not known. OBJECTIVE: To assess the effect of diuretic-based antihypertensive stepped-care treatment on the occurrence of heart failure in older persons with isolated systolic hypertension. DESIGN: Analysis of data from a multicenter, randomized, double-blind, placebo-controlled clinical trial. PARTICIPANTS: A total of 4736 persons aged 60 years and older with systolic blood pressure between 160 and 219 mm Hg and diastolic blood pressure below 90 mm Hg who participated in the Systolic Hypertension in the Elderly Program (SHEP). INTERVENTION: Stepped-care antihypertensive drug therapy, in which the step 1 drug is chlorthalidone (12.5-25 mg) or matching placebo, and the step 2 drug is atenolol (25-50 mg) or matching placebo. MAIN OUTCOME MEASURES: Fatal and nonfatal heart failure. RESULTS: During an average of 4.5 years of follow-up, fatal or nonfatal heart failure occurred in 55 of 2365 patients randomized to active therapy and 105 of the 2371 patients randomized to placebo (relative risk [RR], 0.51; 95% confidence interval [CI], 0.37-0.71; P<.001; number needed to treat to prevent 1 event [NNT], 48). Among patients with a history of or electrocardiographic evidence of prior myocardial infarction (MI), the RR was 0.19 (95% CI, 0.06-0.53; P=.002; NNT, 15). Older patients, men, and those with higher systolic blood pressure or a history of or electrocardiographic evidence of MI at baseline had higher risk of developing heart failure. CONCLUSION: In older persons with isolated systolic hypertension, stepped-care treatment based on low-dose chlorthalidone exerted a strong protective effect in preventing heart failure. Among patients with prior MI, an 80% risk reduction was observed.

Asunto(s)

RESUMEN

Ventricular ectopic activity was recorded at baseline in 5.6% of the 12-lead electrocardiograms and 8.2% of the 2-minute rhythm strips of 4674 subjects with isolated systolic hypertension (systolic blood pressure 160 to 219 mm Hg, diastolic blood pressure < 90 mm Hg) participating in the Systolic Hypertension in the Elderly Program (SHEP). In this study 1.3% had 6 to 10 ventricular premature beats (VPB), and 0.7% had > 10 VPB on the 2-minute rhythm strip. Correlates of VPB presence on the 12-lead ECG were older-age male sex, presence of Q/QS pattern and higher heart rate. Participants with serum potassium < 3.5 mmol/L had a higher prevalence of VPB. Similarly, the number of VPB on the 2-minute rhythm strip was associated with male sex, increasing age, with lower serum potassium, history of palpitations, and presence of Q/QS patterns.

Asunto(s)

Asunto(s)

RESUMEN

It is proposed that chiropractic and nutritional treatment contribute to the amelioration and perhaps reversal of osteoarthritis (OA). It is further proposed that the chiropractic manipulative thrust, is in effect, treating dysfunctional bio-mechanics of joints, affecting positive cartilaginous change. The pathophysiology and multi-factorial causes of OA are reviewed. New interpretations of the literature surrounding OA are discussed which offer arguments for OA's treatment and reversal through chiropractic manipulation and nutrutional support. Presented is a new model of the chiropractic concept of subluxation (abnormal joint complex resulting in fixation or decrease in normal range of motion) and the chiropractic manipulative thrust. The associated histologic correlates are also discussed. A review of the literature of anti-inflammatory and muscle/joint complex supportive nutrients appropriate for OA is presented. Finally, a complete treatment protocol for OA is summarized.

Asunto(s)

Asunto(s)

RESUMEN

This multicenter, double-blind, placebo-controlled study was conducted to evaluate dose-response effects and safety of once-daily administration of pravastatin, a new inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. Pravastatin 5, 10, 20, 40 mg or placebo was administered at bedtime to 150 patients with primary hypercholesterolemia inadequately controlled on a low-fat, low-cholesterol (AHA Phase I) diet. After 8 weeks of treatment, pravastatin produced dose-dependent reductions in low-density lipoprotein (LDL) cholesterol of 19.2 to 34.1% (p less than or equal to .001 vs. baseline and placebo) and reductions in total cholesterol of 14.3 to 25.1% (p less than or equal to .01 to p less than or equal to .001 vs. placebo and p less than or equal to .001 vs. baseline). The relationship between the loge dose of pravastatin and decrease in LDL cholesterol was linear (p less than 0.002). High-density-lipoprotein cholesterol increased up to 11.7% and triglycerides decreased by as much as 23.9%. Pravastatin was well tolerated; no patient withdrew from the study as a consequence of treatment-related adverse events. Despite its relatively short serum half-life of approximately 2 h, once-daily administration of pravastatin provides a safe and effective means of reducing elevated LDL and total cholesterol.

Asunto(s)

Asunto(s)

RESUMEN

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)

Asunto(s)

RESUMEN

The interrelationships among education, smoking, and non-cardiovascular (non-CVD) mortality were examined in middle-aged white males from the Chicago Peoples Gas Company Study (PG), the Chicago Western Electric Company Study (WE), and the Chicago Heart Association Detection Project in Industry (CHA). In each study, college graduates had the lowest prevalence of current smokers and the highest prevalence of former smokers. The associations between education and smoking were strongest in CHA, a study with baseline measurements 10-14 years after those of PG and WE and 3-8 years after the US Surgeon General's report on smoking and health in 1964. In PG and WE, the relative risks of non-CVD death for those who did not attend college compared to those who did were 1.50 and 1.38 (95% limits, 1.04 to 2.18 and 0.95 to 2.02). In CHA, the relative risk for those who did not graduate from college compared to those who did was 1.55 (1.17, 2.05). Differences in baseline cigarette smoking could account for only 23-29% of these increased risks. Because the associations between education and non-CVD mortality may have been confounded by changes in smoking status over the course of follow-up in these studies, non-CVD deaths were subdivided into those from causes related to smoking and causes not related to smoking. For smoking-related causes, the relative risk of death for those who did not attend/graduate from college was 1.95 (0.96, 3.95) in WE, 2.13 (1.18, 3.87) in PG, and 2.34 (1.47, 3.84) in CHA, while the relative risks for causes not related to smoking were 1.17, 1.12 and 1.16, respectively. These findings suggest that education is related inversely to non-CVD mortality primarily through smoking and smoking-related causes of death. With smoking becoming increasingly a habit of the less well-educated, these findings underscore the need for smoking prevention and cessation programmes targeted at the lower end of the socioeconomic scale.

Asunto(s)

RESUMEN

A two-center, randomized, controlled trial designed to evaluate and compare an alpha blocker and a diuretic as initial antihypertensive drug treatment is currently in progress. Approximately 100 men and women, aged 30 to 69 years, are being randomly assigned to treatment with either of these two agents. If diastolic blood pressure is not reduced to its target level and is 85 mm Hg or higher, the alternate agent is added. The alternate agent is substituted if a patient does not tolerate the assigned agent. This preliminary report presents data concerning 62 patients who completed at least three of the planned 12 months of drug treatment. At that point, the alpha blocker prazosin and the diuretic hydrochlorothiazide were similar in their ability to lower the average diastolic blood pressure to normal levels. Serum total cholesterol and triglyceride levels declined in prazosin-treated patients but increased in hydrochlorothiazide-treated patients, a difference that was statistically significant. No significant weight change, a possible confounding variable, occurred in either group. More patients were unable to tolerate prazosin than were unable to tolerate hydrochlorothiazide (10 of 30 receiving prazosin, compared with three of 32 receiving hydrochlorothiazide). For those able to continue with prazosin, the favorable lipid response appears to be an asset in regard to reducing possible atherogenic effects of treatment.

Asunto(s)

RESUMEN

In 1975-1978, the Chicago Department of Health conducted a screening program that included measurements of blood pressure, heart rate, height, weight, triceps skinfold thickness, and arm circumference, and calculation of body mass index and muscle circumference for non-public school children. Based on data on 4,086 boys and girls aged 5-10 years from the program, this study examined the ethnic differences in blood pressure and heart rate among children of white, black, Latino, and Oriental ethnicity. Mean levels for both systolic and diastolic blood pressure were higher for Oriental and black children than for white and Latino children. These differences were independent of age, height, weight, and skinfold thickness. The black children had a much lower mean heart rate than the other children. A seasonal variation was observed for systolic blood pressure, i.e., with each sex group, the mean systolic blood pressure adjusted for age, skinfold thickness, and height tended to be higher in spring than in fall and winter. (Note-- no child was screened during the summer because of summer break.) With control for season, ethnic differences in systolic blood pressure disappeared, but not the ethnic differences in diastolic blood pressure and heart rate.

Asunto(s)

Asunto(s)

RESUMEN

Quit-rates for cigarette smokers in a lifestyle intervention program aimed at reducing coronary risk were 24 percent for all participants and 34 percent for non-dropouts. Recidivism remained very low during participation in the program. Half of the smokers who quit did so after being in the program more than two years. These data suggest that while engaging in an effort to make other changes in lifestyle, many smokers can be helped to quit. Sustained antismoking efforts in the clinical practice of medicine can be expected to share these same positive aspects. While mass public health programs to eliminate smoking and prevent young people from taking up the habit are being developed, health practitioners can make a significant contribution by including vigorous efforts at smoking cessation as part of routine practice.

Asunto(s)

RESUMEN

Because systolic blood pressure rises more sharply with age than diastolic blood pressure, leading to an increasing prevalence with advancing age of elevated systolic blood pressure without elevated diastolic pressure, i.e. so-called pure systolic hypertension, the question arises as to whether or not pure systolic hypertension has its own etiology and pathogenesis. Since pure systolic hypertension is characterized by a widened pulse pressure, the present report examined the association between relative weight and pulse pressure, both cross-sectionally and prospectively, in addition, to the association between relative weight and the level of blood pressure, in four Chicago epidemiologic studies. The positive association between relative weight and the level of blood pressure in these studies, in both cross-sectional and prospective analyses, reaffirms the finding in previous studies of a positive association between weight and blood pressure and the prevalence and incidence of hypertension. However, the results of these studies did not generally support the hypothesis that relative weight is related to pulse pressure, and thus possibly to pure systolic hypertension.

Asunto(s)

RESUMEN

Two methodological problems in characterizing an individual's plasma glucose level are examined in this study. First, how large is the intra-individual variation of an individual's 1-hr post-load glucose level and for this estimated intra-individual variation what are the probabilities of misclassifying individuals based on a one-time measurement only of glucose level? Second, do different tests-i.e. fasting, 1-hr, 2 hr post-load, GTT-yield consistent ranking for the same individual? The first of these was explored with data on subsamples from the Chicago Peoples Gas Company (PG) study and the Chicago Heart Association Detection Project in Industry (CHA) study; the second, with data from the Chicago Coronary Prevention Evaluation Program (CPEP). For both the PG and CHA studies, the estimated ratios of the intra- to inter-individual variances were generally higher for post-load plasma glucose than blood pressure, heart rate, weight and serum uric acid. The conditional probabilities of misclassifying individuals into quintiles or deciles based on one measurement of 1-hr post-load glucose were also estimated from these data. These estimated probabilities indicated that the possible attenuation due to intra-individual variation cannot abolish a strong association; however, it may create some problem if the relationship is not very strong. Furthermore, both rank correlation and quintile classification analyses show that fasting, 1-hr and 2-hr plasma glucose level characterize individuals differently. Thus it is possible that the inconsistent results of previous studies, all using a one-time measure of plasma glucose, are partially due to the large intra-individual variation of this variable, and the use of methods that are not highly consistent in their classification of individuals.

Asunto(s)

RESUMEN

Because systolic blood pressure rises more sharply than diastolic blood pressure for those middle aged and beyond, leading to an increasing prevalence with advancing age of elevated systolic blood pressure without elevated diastolic pressure, i.e. so-called pure systolic hypertension, the question arises as to whether or not factors that have been shown to be related to blood pressure and hypertension are related to pure systolic hypertension or to 'classical' hypertension, i.e. hypertension defined solely by the level of the diastolic pressure. This question was examined in four Chicago epidemiologic studies by examining the associations between several variables and pulse pressure, with pulse pressure redefined so that the association between a variable and pulse pressure indicated whether the variable was more strongly related to systolic or diastolic blood pressure. In these four studies, glucose, heart rate and cigarette use tended to show a stronger association with systolic pressure, suggesting a possible association with pure systolic hypertension, while hematocrit, serum cholesterol, and uric acid tended to be more strongly associated with diastolic pressure, or equally associated with systolic and diastolic pressure, suggesting an association with 'classical' hypertension. Relative weight tended to be more strongly associated with systolic pressure under the age of 35 and more strongly associated with diastolic pressure after age 45.

Asunto(s)

RESUMEN

This report, the second in a series on pulse pressure and pure systolic hypertension, examined in prospective analyses the associations between both the initial values of five variables and the changes in these variables and pulse pressure, utilizing data from three Chicago epidemiologic studies, in order to determine whether variables known to be related to blood pressure and hypertension are related to pure systolic hypertension or 'classical' hypertension. In these analyses follow-up pulse pressure, which was measured from 2-5 years after the initial measurement of the other variables, was redefined so that the association between the initial value or change and pulse pressure indicated whether the initial value or change was more strongly related to follow-up systolic or diastolic blood pressure. In these three studies, only the initial value for cigarette use had a consistent positive association with follow-up pulse pressure. Change in heart rate was generally positively related to follow-up pulse pressure, while the initial value was not. For relative weight and serum cholesterol, both the change and the initial tended to be negatively related. For glucose, the association was not consistent for either the initial value or the change. The results from these prospective analyses thus suggest that cigarette use is related to pure systolic hypertension, rather than 'classical' hypertension.

Asunto(s)

RESUMEN

This report, the third in a series on pulse pressure and pure systolic hypertension, examines the associations between blood pressure and the cardiovascular diseases and coronary heart disease, both cross-sectionally and prospectively, utilizing data from four Chicago epidemiologic studies, in an effort to determine whether or not a widened pulse pressure, or pure systolic hypertension, is an independent risk factor. In these analyses, blood pressure is divided into two components, one related to level and the other to pulse pressure, with pulse pressure redefined so that the association between pulse pressure and the prevalence of ECG abnormalities or mortality, indicates whether the endpoint is more strongly related to systolic or diastolic blood pressure. In these studies, blood pressure level is significantly related to both ECG abnormalities and mortality. In the cross-sectional analyses, pulse pressure is generally positively related to the prevalence of ECG abnormalities, indicating a stronger association for systolic blood pressure, and thus a possible association with pure systolic hypertension. However, in the prospective analyses, pulse pressure is generally not related to mortality, indicating an equal association with mortality for systolic and diastolic blood pressure in these studies. Thus, although the cross-sectional analyses generally support the hypothesis that a widened pulse pressure, or pure systolic hypertension, is an independent risk factor for the cardiovascular diseases and coronary heart disease, the prospective analyses do not.

Asunto(s)