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Biomedical subjects

A Dyer

Publications and source records attributed to A Dyer.

At least 55 records · Page 3Linked to original sources
PubMed1986

Initial antihypertensive drug therapy: alpha blocker or diuretic. Interim report of a randomized, controlled trial.

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.

Adrenergic alpha-Antagonists↗
PubMed1986

Characteristics and prognosis of incomplete right bundle branch block: an epidemiologic study.

A cohort of 1,960 white men aged 40 to 56 years without initial apparent heart disease and with 11 years of annual rest electrocardiograms and 20 year mortality data was followed in the Chicago Western Electric Company Study. Incomplete right bundle branch block was found in 134 men (6.8%) at entry. During follow-up, 222 men developed such block, an incidence rate of 13.6%. Left axis deviation of -30 degrees or less was more frequent in men with than in those without incomplete block at entry (8.2 versus 2.4%). Men with left axis deviation also had a higher incidence of incomplete right bundle branch block. Similarly, men developing incomplete block had a significantly greater risk of developing left axis deviation. The associations between incomplete block and left axis deviation were unrelated to age and body weight. Men with incomplete block had a significantly greater likelihood of developing complete right bundle branch block. The 11 year incidence rate of complete block was 5.1% for men with baseline incomplete block and 0.7% for those without. Complete block developed in 2 of 220 incident cases of incomplete block but in none of the 440 control men matched by age and duration of follow-up. Although incomplete right bundle branch block was not related to an increased risk of death in 20 years from coronary heart disease and cardiovascular diseases, the study data suggest that such block is frequently a manifestation of primary abnormality of the cardiac conduction system in middle-aged men.

Actuarial Analysis↗
PubMed1986

Relationship of clinical diabetes and asymptomatic hyperglycemia to risk of coronary heart disease mortality in men and women.

This epidemiologic study explored the sex differential in risk of death from coronary heart disease in persons with or without clinically diagnosed diabetes or asymptomatic hyperglycemia. Use was made of 9-year follow-up data from the Chicago Heart Association Detection Project in Industry for 11,220 white men and 8,030 white women aged 35-64 years at entry to the Project (November 1967-January 1973). Both clinically diagnosed diabetes and asymptomatic hyperglycemia were associated with an increased risk of death from coronary heart disease. The extent of this association was greater in women than in men in regard to relative risk. However, absolute excess risk for both diabetics and those with asymptomatic hyperglycemia was larger for men than for women. Clinical diabetes appeared to be an independent risk factor for coronary heart disease in both men and women based on multivariate Cox regression analyses. On the other hand, for men, no significant independent effect of asymptomatic hyperglycemia was apparent. Women with asymptomatic hyperglycemia had significantly higher coronary heart disease death rates than normoglycemic women, with adjustment for major coronary heart disease risk factors; in multivariate analyses, the relationship of asymptomatic hyperglycemia to risk of coronary heart disease was of borderline significance (p = 0.054). This study indicates the independent associations of diabetes and possibly asymptomatic hyperglycemia with coronary heart disease mortality, with greater relative significance in women than in men.

Adult↗
PubMed1986

The role of weight in the positive association between age and blood pressure.

This study used cross-sectional data for 19,704 white men and 13,895 white women from the Chicago Heart Association Detection Project in Industry (November 1967 to January 1973) to investigate whether weight explains the association between age and blood pressure, and in particular, whether age is associated with blood pressure and hypertension in the absence of overweight. The relations among age, relative weight, and blood pressure were examined through assessment of mean blood pressure levels and prevalence of hypertension in 25 subgroups stratified by age (18-24, 25-34, 35-44, 45-54, and 55-64 years) and by relative weight (less than 100%, 100-109%, 110-119%, 120-134%, and greater than or equal to 135%). For all five relative weight groups, for both men and women, mean diastolic blood pressure was higher at successive ages. This phenomenon was also seen for systolic blood pressure after ages 35-44 years for men, and after ages 25-34 years for women. On the other hand, the higher the relative weight was, the higher the blood pressure was. Regression analysis demonstrated that the observed relation between age and blood pressure was consistent for all five relative weight groups, including those at desirable weight. These data indicate that for US subjects, age and blood pressure are generally associated in the absence of overweight.

Adolescent↗
PubMed1986

Time trends in the US racial difference in hypertension.

This paper explores time trends in racial differences in hypertension and in mortality from complications from hypertension in the United States. Mortality data were derived from death certificate data compiled by the National Center for Health Statistics and presented in the 1981 Report of the Working Group on Arteriosclerosis. Prevalence data were obtained from five populations--6,672 people screened in 1960-1962 by the National Health Examination Survey (NHES); 20,749 screened in 1971-1975 by the Health and Nutrition Examination Survey (HANES I); 158,539 screened in 1973-1974 by the Hypertension Detection and Followup Program (HDFP); 1 million persons screened in 1973-1975 by the Community Hypertension Evaluation Clinics (CHEC); and 20,325 screened in 1976-1980 by the second Health and Nutrition Examination Survey (HANES II). Mortality data indicate that the nonwhite/white ratios for mortality from complications of hypertension increased between 1940 and 1967 and decreased between 1968 and 1978. Prevalence data show a corresponding recent decrease in black minus white mean blood pressure. Some of the decrease appears to be due to a greater improvement in hypertension control for blacks than for whites. Time trends in the black/white ratio in prevalence of hypertension were examined with differential treatment effects controlled by inclusion as hypertensive those on drug therapy. The results indicate that in addition to differential changes in therapy, the ratio of black/white prevalence of hypertension may also be decreasing. Additional studies are needed to confirm this finding and to explore time changes in racial patterns of risk factors for hypertension.

Black People↗
PubMed1985

Nonpharmacological control of hypertension.

Ability to safely withdraw well-controlled mild hypertensives from drugs is being tested in a three-group randomized trial. Group I (intervention) was removed from drugs after the first 2 months of nutrition counseling. Counseling is continuing through the remaining years of the trial to achieve a minimum weight loss of 10 lb if overweight, reduction of sodium intake to less than 1,800 mg, and reduction of alcohol intake to not more than two drinks per day. Group II (the first control group) was also removed from drugs to see if previous long-term blood pressure control had a carryover effect without dietary change. Blood pressure is monitored frequently in both groups, with return to drug treatment in the event of specified blood pressure rise. Group III (the second control group) has remained on drugs for comparison of blood pressure and biochemical variables. In Group I mean 30-month weight loss was 8 lb, with 35% losing 10+ lb; sodium intake was reduced by 38%. Blood pressure control without drugs was maintained for 47% of Group I patients but only 16% of group II patients (P less than 0.05). These findings indicate it may be possible, after establishing good blood pressure control, to maintain control in a sizable proportion without medication, when reduction of weight, sodium, and alcohol intake is achieved.

Alcohol Drinking↗
PubMed1984

Trial on control of hypertension by nutritional means: three-year results.

Ability to safely withdraw medication from well-controlled mild hypertensives was tested in a 3-group randomized trial. Group I (Intervention): drugs were stopped 2 months after nutrition counseling began. Counselling continued throughout the remaining years of the trial to achieve: a minimum of 10 lb weight loss if overweight; reduction of sodium intake to 1800 mg/day or less; reduction of alcohol intake to not more than 2 drinks per day. Group II (control group 1): drugs were stopped to see if previous long-term blood pressure control had a carryover effect without diet change. Pressure was monitored frequently in both groups with return to treatment if diastolic blood pressure rose to 90 mmHg or above. Group III (control group 2) remained on drugs for comparison of blood pressure and biochemical variables. In Group I mean weight loss at 3 years was 7 lb (3.18 kg) with 39% losing 10 lb (4.55 kg) or more; sodium intake was reduced by 37%. Blood pressure control without drugs was achieved in 44% of Group I patients. This compares with only 15% in Group II. These findings suggest it may be possible after establishing good blood pressure control, to maintain control in a sizeable proportion with less or no medication, when reduction of weight, sodium, and alcohol is achieved.

Antihypertensive Agents↗
PubMed1983

The development of a profile scoring system for early identification and severity assessment of pregnancy-induced hypertension.

Two commonly encountered problems in the management of patients with pregnancy-induced hypertension (PIH) or pregnancy-aggravated hypertension (PAH) are (1) a delay in early recognition of disease, and (2) imprecise assessment of the severity of the disease. Gravid women suffering from PIH may present in a protean manner which can be misleading to the clinician who relies strictly upon classic clinical parameters in the management of the patient. Many hematologic changes associated with PIH have been documented. However, a comprehensive evaluation of these changes, as depicted by simultaneous laboratory testing, has not been reported. The purpose of this study was twofold: (1) to formulate a profile scoring system in which clinical parameters and laboratory tests were utilized in concert, not as a predictor, but as a standardized method of early recognition of PIH, and (2) to evaluate the profile scoring system's accuracy in assessing the severity of the disease. Empirically, a "profile" was developed that included five clinical parameters (rollover test, mean arterial blood pressure, ocular arteriolar vasospasm, hand and facial edema, patellar reflexes) and eight laboratory tests (urine protein, serum urate, urea nitrogen, creatinine, albumin, total proteins, platelet count, and plasma fibrinogen). Values for each parameter and test were categorized into the accepted normal and abnormal ranges for pregnancy. On the basis of the degree of abnormality, weighted numerical scores of increasing magnitude were arbitrarily assigned to the respective value ranges. For a given patient, the sum of the individual parameter and test scores constituted the profile score. The sample population consisted of 108 patients with "at risk" characteristics or clinical manifestations of PIH. From one to six profile scores per patient were obtained between 24 weeks' gestation and the onset of labor. Simultaneously, the clinical status of the patient was evaluated and assigned to one of four categories: (1) no PIH, (2) incipient PIH, (3) mild PIH, and (4) severe PIH. Of the 108 sample patients, 14 did not develop clinical PIH (no PIH), 17 developed mild gestational or intrapartum hypertension only (incipient PIH), 45 manifested mild preeclampsia (mild PIH), and 32 demonstrated severe preeclampsia (severe PIH), four of whom were eclamptic. Profile scores +/- standard error of the mean (SEM) relative to the patient's clinical status were as follows: no PIH = 7.1 +/- 0.5, incipient PIH = 10.7 +/- 0.4; mild PIH = 15.5 +/- 0.4; and severe PIH = 28.3 +/- 0.9. On the basis of our study data, we believe that profile scoring is an effective system for the early identification of PIH. Also, we believe that, when patients with clinically overt PIH are evaluated, this approach enhances our ability to quantitate the severity of the disease objectively.

Blood Pressure↗
PubMed1983

A simple estimated fetal weight equation based on real-time ultrasound measurements of fetuses less than thirty-four weeks' gestation.

Based on ultrasonographic mensuration, a number of equations have previously been devised for the purpose of estimating fetal weights. The objective of this study was to develop a mathematical equation that is simple, accurate, and easy to use when applied to preterm or low-birth weight fetuses (less than 2,500 gm). Real-time ultrasound measurements of fetal biparietal diameters (BPDs) and abdominal circumferences (ACs) were obtained in 62 pregnant women within one week of premature delivery. Mean gestational age and mean birth weight +/- SD for this study group of neonates were 28.5 +/- 3.5 weeks and 1,135 +/- 343 gm, respectively. With the aid of computer analysis, a simple regression equation was derived: EFW = (BPD x AC x 9.337) - 229. When predicted estimated fetal weight (EFW) was compared with actual birth weight (ABW), multiple regression analysis demonstrated a correlation coefficient (R) of 0.957. Preliminary results on 19 patients of a prospective study showed an absolute mean difference between the computed EFWs and the ABWs to be within 7.0% of ABW (70 gm/kg of ABW). The standard deviation of the difference was 9.3% of ABW (93 gm/kg of ABW). Based on these data, this simple equation appears to be clinically reliable and easy to use when estimating weights of preterm or low-birth weight fetuses of less than 2,500 gm.

Birth Weight↗
PubMed1981

Ultrasonic induction of sister chromatid exchanges in human lymphocytes.

We analyzed sister chromatid exchange (SCE) frequencies as an indicator of DNA damage induced in human lymphocytes by 'real-time' ultrasound. A range of exposure times and intensities was tested in a series of blind, randomized, in vitro experiments under spatial and sonographic conditions simulating exposure of a gravid abdomen and uterus. Our studies showed small but consistent effects of ultrasound on SCE frequencies, for each experiment. Differences between matched control and exposed means were significantly different from zero. chi 2 tests for homogeneity indicated no significant differences among either the means or the total distributions of the controls, nor among each of the separate dose levels. Consequently, experiments were pooled, and chi 2 analysis indicated significant differences both among distributions and among means of SCE frequencies for controls versus exposed cells (P less than 0.001). The pooled control mean was also significantly different from each of the pooled dose means. Correcting for multiple comparisons gave identical results for the paired comparisons of means except for the 20-min level which was borderline (0.025 less than P less than 0.01). We conclude that the well-established value of clinical ultrasonography warrants its continued use; however, minimizing the numbers and lengths of exposure per patient would seem prudent, pending further information on clinical implications of our results.

Adult↗