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Biomedical subjects

R D Abbott

Publications and source records attributed to R D Abbott.

At least 127 records · Page 7Linked to original sources
PubMed1983

Association of hyperestrogenemia and coronary heart disease in men in the Framingham cohort.

The serum levels of estradiol and testosterone as well as established risk factors for coronary heart disease were estimated in 61 men (mean age 70.0 +/- 6.4 [SD] years) with coronary heart disease and in 61 matched control subjects enrolled in the Framingham Heart Study. The mean serum estradiol level was significantly higher in the subjects with coronary disease (p = 0.011). This difference in estradiol level increased with the exclusion of subjects older than 75 years (p less than 0.001). The mean serum testosterone level was not significantly different. None of the established risk factors for coronary heart disease was different between subjects with coronary disease and control subjects except blood glucose level, which was higher in the subjects with coronary disease (p = 0.025). We conclude that hyperestrogenemia is an important correlate of coronary heart disease in men.

Adult↗
PubMed1983

Alcohol and coronary heart disease in Puerto Rico.

The relationship of alcohol consumption, measured in 1965-1968 by the 24-hour recall method, to incident coronary heart disease morbidity at eight years and mortality at 12 years of follow-up was investigated in a cohort of 9150 Puerto Rican males 35-79 years of age. After adjustment for age, cigarettes, exercise, urban/rural status, and income, there was clear evidence of a "U-shaped" relationship between alcohol and total mortality, and also the suggestion of a "J-shaped" relationship for angina pectoris, nonfatal myocardial infarction, and nonsudden coronary heart disease death. There was no association of alcohol with sudden cardiac death. The adjusted odds ratio for drinkers versus nondrinkers was 0.6 for angina pectoris (p less than 0.05), 0.7 for nonfatal myocardial infarction (p less than 0.1), and 0.7 for nonsudden coronary heart disease death (p less than 0.05). The inverse association of alcohol consumption to nonsudden coronary heart disease death was found to be dependent on age and income: the adjusted odds ratio for subjects under age 60 (0.4) or over the median income (0.3) strongly favored drinkers, while there was no evidence for a "protective effect" of alcohol consumption in the older and poorer segments of the population. It is concluded that available evidence does not justify the assertion that the inverse association between moderate alcohol intake and coronary heart disease risk is a causal one.

Adult↗
PubMed1983

Summary estimates of cholesterol used to predict coronary heart disease.

The relationships of total cholesterol and the proportion of cholesterol in individual lipoprotein classes to coronary heart disease are complex. To help simplify these relationships, cholesterol values are often combined into one summary estimate to form a single risk factor with a relationship to disease that is more easily described. Although summary estimates result in convenient expressions relating cholesterols to coronary heart disease, there is the potential for sacrificing information by ignoring the joint configuration of cholesterols that make up these estimates. We investigated the extent of this possibility for the ratio of total cholesterol to high-density lipoprotein cholesterol and the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol. The findings suggest that the summary estimates are useful expressions for combining cholesterol information and are strong predictors of coronary heart disease. Clinicians who choose to use a summary estimate for screening purposes should recognize that a single ratio estimate is not always as informative as the joint configuration of the cholesterols that make up the estimate. This possibility is most clearly exhibited for the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol, and it may become more apparent in future studies as the capabilities of exploring lipoprotein cholesterol relationships improve.

Aged↗
PubMed1982

Epidemiologic features of chronic atrial fibrillation: the Framingham study.

In the Framingham Study 2325 men and 2866 women 30 to 62 years old at entry were followed biennially over 22 years for the development of chronic atrial fibrillation in relation to antecedent cardiovascular disease and risk factors. During surveillance, atrial fibrillation developed in 49 men and 49 women. The incidence rose sharply with age but did not differ significantly between the sexes. Overall, there was a 2.0 per cent chance that the disorder would develop in two decades. Atrial fibrillation usually followed the development of overt cardiovascular disease. Only 18 men and 12 women (31 per cent) had chronic atrial fibrillation in the absence of cardiovascular disease. Cardiac failure and rheumatic heart disease were the most powerful predictive precursors, with relative risks in excess of sixfold. Hypertensive cardiovascular disease was the most common antecedent disease, largely because of its frequency in the general population. Among the risk factors for cardiovascular disease, diabetes and electrocardiographic evidence of left ventricular hypertrophy were related to the occurrence of atrial fibrillation. The development of chronic atrial fibrillation was associated with a doubling of overall mortality and of mortality from cardiovascular disease.

Adult↗
PubMed1982

A blood ordering strategy for hospital blood banks derived from a computer simulation.

The ultimate goal of a hospital blood bank inventory control programs is to reduce wastage of blood products and unnecessary use of laboratory services without jeopardizing patient safety. The development of a practical blood ordering policy at the hospital level is an integral part of any such program. In order to explore various blood ordering options in detail, a computer simulation of a hospital blood inventory was used to assess the impact on blood band performance measures of reductions in group O and non-group-O levels from baseline levels, assuming both a 21-day and 35-day shelf life. On the basis of data derived from this study showing that such inventory reductions accompanied by partial protection of the group O inventory will not result in significant shortages, a practical strategy was developed for establishing optimal target inventory levels for a hospital on an empirical basis. These target levels can serve as a guide for subsequent blood ordering. A step-by-step approach for analyzing a hospital blood inventory control program is then suggested, accompanied by an action plan for implementing change which incorporates the experimentally-derived blood ordering strategy. Adherence to this plan should result in a low outdate rate, a reduction in unnecessary cross-matching, and greater availability of blood for those patients with a legitimate need for it.

ABO Blood-Group System↗
PubMed1981

Influence of kaolin-pectin suspension on steady-state plasma digoxin levels.

The effect of a kaolin-pectin antidiarrheal mixture on steady-state plasma levels of orally administered digoxin in subjects receiving chronic digoxin therapy was evaluated when the antidiarrheal and the cardiac glycoside were given concomitantly and when two doses of antidiarrheal were given, one 2 hours before and the other 2 hours after digoxin. Although simultaneous administration of both products decreased peak digoxin levels by 36 per cent, 24-hour areas under the curve were reduced by only 15 per cent, indicative of a slight decrease in digoxin bioavailability. In contrast, when their times of administration were separated by 2 hours, no evidence of a drug interaction was noted. Hence, the effect of one or two doses of kaolin-pectin suspension on steady-state plasma levels of digoxin appears inconsequential in patients on chronic digoxin therapy. Saliva levels were poorly correlated with plasma levels, presumably because of complexation in the oral cavity.

Absorption↗
PubMed1981

Estimation of very-low-density lipoprotein cholesterol from data on triglyceride concentration in plasma.

We examined the relationship in a large-living population between the concentration of triglycerides in plasma from fasting persons and the concentration of very-low-density lipoprotein cholesterol (VLDL-C) as determined after preparative ultracentrifugation. Data from individuals in the Framingham Heart Study who were free of coronary heart disease, did not have Fredrickson Type I, III, or V hyperlipoproteinemia, and whose plasma-triglyceride values were less than 4000 mg/L were considered in the analyses. A total of 4100 Framingham Offspring, ages 20-49 years, met these criteria, as did 2284 participants in the original Framingham Cohort, aged 50-79 years. We estimated a linear regression model with an intercept and slope coefficient, using VLDL-C (units, mg/L) as the dependent variable and triglycerides as the dependent variable. The intercept was approximately 30.0 mg/L, and the slope coefficient for triglycerides was about 0.20 when all age and sex groups were combined. However, when the analysis was performed by age group, the slope coefficient for triglycerides increased with each age group only for women. The model, in which a different intercept and slope is used for each age and sex group was statistically better than a previously developed simpler model. On the other hand, the older model, in which VLDL-C is easily estimated by multiplying the triglyceride value by 0.20, is reasonably accurate and is very simple to use. The generalizability of the model is discussed in the light of results from other population studies.

Adult↗
PubMed1976

A comparison of myocardial function in former athletes and non-athletes.

Heart rate (HR), total electromechanical systole (Q-S2), left ventricular ejection time (LVET), pre-ejection period (PEP), and diastole (D) were compared in 350 former athletes and 156 non-athletes, age 27-74. The two cohorts had been equated according to habitual leisure time physical activity. Former athletes exhibited significantly longer Q-S2 and PEP at rest, and significantly lower HR and lengthened Q-S2, LVET, PEP, and D at one minute following a standard two minute step test (less than 0.05). Significantly differences were observed between athletes and non-athletes in the light and moderate activity categories. There were no significant differences between former athletes and non-athletes currently engaged in strenuous leisure time physical activity. Comparisons were made among the three levels of habitual leisure time physical activity with each group and revealed that HR was lower and Q-S2, LVET, PEP, and D were longer at rest and following exercise as the level of physical activity increased. There were more significant differences among former athletes than among non-athletes. Most of these differences were between light to moderate and light to strenuous levels of activity. The evidence suggests an advantage in myocardial function among former athletes compared to their non-athlete counterparts.

Adult↗