Biomedical subjects

J J Barboriak

Publications and source records attributed to J J Barboriak.

At least 19 recordsLinked to original sources

PubMed1992

The relation of prothrombin times to coronary heart disease risk factors among men aged 31-45 years.

Although levels of coagulation factor VII and fibrinogen are predictive of cardiovascular disease, relatively little data describe hemostatic characteristics in healthy populations. The cross-sectional associations between the prothrombin time, a measure of the activity of the extrinsic and common pathways of coagulation, and traits associated with the risk of cardiovascular disease were therefore examined among 3,604 white and 514 black, male, US Army veterans aged 31-45 years. The prothrombin time measurements, performed in 1985 and 1986, were precise, with an intraclass correlation of 0.98 (202 pairs). Overall, the mean prothrombin time was 12.4 seconds (standard deviation, 0.4 seconds), and 11 percent of the men had a value of less than 12 seconds. Many of the observed associations with the prothrombin time paralleled those that have been reported with clotting factor VII and fibrinogen. The mean prothrombin time was 0.15 seconds shorter among whites than among blacks and was 0.2 seconds shorter among current cigarette smokers than among men who had never smoked. Inverse associations were also seen with relative weight and with levels of total cholesterol and triglycerides (r = -0.09 to -0.16). All associations were statistically significant at the 0.01 level, and the examined characteristics could jointly account for about 12 percent of the variability in prothrombin times. Additional data on characteristics related to coagulation may help elucidate the natural history of cardiovascular disease and aid in the design of clinical trials.

Adult↗

PubMed1992

Cholesterol and coronary artery disease: age as an effect modifier.

An elevation of serum cholesterol has been one of the more frequently cited risk factors for coronary heart disease, found in both case-control and cohort studies. As a result, this country has undertaken massive screening of adults older than 20 years of age in an attempt to identify those persons with cholesterol levels greater than 200 mg/dl, and follow up with an active approach for intervention. The suggested cutpoints for borderline (200-240 mg/dl), and definite (> or = 240 mg/dl) hypercholesterolemia have been applied to all age groups despite suggestions of a diminution of risk conferred by cholesterol in the elderly. This study of 2544 white men undergoing coronary angiography shows that for all men, aged 25-84 years, plasma cholesterol levels were associated with an increase in coronary artery occlusion (rs = 0.15, p < 0.01). However, when stratified by age, this association held only for the younger men, the association diminishing to near zero in the oldest age group. The negative interaction between cholesterol levels and age in predicting coronary artery disease proved highly significant (p < 0.001) in multivariable linear regression analysis, suggesting that cholesterol levels are much less predictive of coronary artery disease in the elderly as compared to the young. These results point to the need for a more finely tuned set of criteria for the evaluation of hypercholesterolemia, one that takes into account the age of the screenee.

Adult↗

PubMed1992

Alcohol produces dose-dependent antiatherogenic and atherogenic plasma lipoprotein responses.

A comprehensive assessment of lipoprotein compositional/metabolic response to incremental caloric ethanol (EtOH) doses ranging from low to moderate to high was undertaken using male squirrel monkeys. Control monkeys were maintained on a chemically defined, isocaloric liquid diet, while experimental primates wee fed increasing doses of alcohol (6, 12, 18, 24, 30, and 36% of energy) substituted isocalorically for carbohydrate at 3-month intervals. Liver function tests and plasma triglyceride were normal for all animals. Plasma cholesterol showed a transient increase at the 12% caloric dose that was attributed solely to an increase in high density lipoprotein (HDL). A more pronounced increase in plasma sterol, beginning at 24% and continuing to 36% EtOH, was the result of increments in both HDL and low density lipoprotein (LDL) cholesterol, although the contribution by the latter was substantial primarily at the 36% dose. Plasma apolipoprotein elevations (HDL apolipoprotein A-I, LDL apolipoprotein B) generally accompanied the lipoprotein lipid increases, although the first atherogenic response for LDL became manifest as a significant increase in apolipoprotein B at 18% EtOH calories. Postheparin plasma lipoprotein lipase was not affected by dietary alcohol, whereas hepatic triglyceride lipase activity showed significant increases at higher (24 and 36%) EtOH doses. Plasma lecithin-cholesterol acyltransferase activity was normal at the 6 and 12% EtOH doses, but exhibited a significant reduction beginning at 18% and continuing to 36% EtOH. Alterations in these key lipoprotein regulatory enzymes may represent the underlying metabolic basis for the observed changes in lipoprotein levels and our earlier findings of HDL2/HDL3 subfraction modifications. Results from our study indicate that in squirrel monkeys, moderate (12%) EtOH caloric intake favors an antiatherogenic lipoprotein profile (increases HDL, normal LDL levels, and lecithin-cholesterol acyltransferase activity), whereas higher doses (24-36%) produce both coronary-protective (increases HDL) and atherogenic (increases LDL) responses. Moreover, the 18% EtOH level represents an important transition dose which signals early adverse alterations in lipoprotein composition (increases apolipoprotein B) and metabolism (decreases lecithin-cholesterol acyltransferase).

Animals↗

PubMed1991

Effect of ethanol on low density lipoprotein and platelet composition.

The present study was designed to investigate the effect of ethanol (EtOH) dose on low density lipoprotein (LDL) and platelet composition. Male squirrel monkeys were divided into three groups designated Control, Low, and High EtOH, and fed isocaloric liquid diets containing 0%, 12%, and 24% of calories as EtOH, respectively. After four months of treatment, monkeys fed the 12% alcohol dose had LDL and platelet cholesterol concentrations similar to Controls. By contrast, platelet membranes from High EtOH animals contained significantly more cholesterol which was associated with higher levels of plasma LDL cholesterol and apolipoprotein B. Blood platelet count, size, and mass were similar for all groups and circulating platelet aggregates were absent in the two alcohol cohorts. Despite elevations in platelet cholesterol mass and thromboxane A2 (TXA2) precursor, phospholipid arachidonate, platelet responsiveness, measured as thromboxane formed in response to a collagen challenge in vitro, and the cholesterol/phospholipid molar ratio, were not significantly altered by high dose alcohol. Normal platelet activity in High EtOH monkeys may have resulted from a significant increase in the platelet phospholipid polyunsaturated/saturated fatty acid ratio and a non-significant increase in platelet phospholipid mass, both of which would have a fluidizing effect on platelet membranes. Our data indicate that low EtOH intake has no effect on platelet composition and function while unfavorable platelet cholesterol enrichment following consumption of high dose ethanol may arise from elevations in plasma LDL.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcohol Drinking↗

PubMed1991

Effect of drinking pattern on plasma lipoproteins and body weight.

The effect of drinking pattern on plasma lipoproteins and body weight was examined in three groups of squirrel monkeys: (1) controls fed isocaloric liquid diet; (2) regular drinkers given liquid diet containing ethanol (EtOH) substituted isocalorically for carbohydrate at 12% of calories daily; and (3) binge drinkers fed 6% EtOH calories daily for a four-day period followed by three days of 20% EtOH to mimic a weekend bout drinking cycle. The number of calories offered per day was the same for all groups, and the average weekly EtOH consumption (12% calories) was identical for the two alcohol treatments. The entire study lasted six months. There were no significant differences in plasma cholesterol, triglyceride or liver function tests. Regular drinkers had the highest high density lipoprotein2/high density lipoprotein3 (HDL2/HDL3) protein and apolipoprotein A-I/B ratios of any group and exhibited a significant elevation in the molar plasma lecithin:cholesterol acyltransferase (LCAT) rate (nmol/min/ml). Binge drinking produced a selective increase in low density lipoprotein (LDL) cholesterol and apolipoprotein B, and a depression in the fractional LCAT rate (% esterified/min). During the course of the study, controls ate 92% of their diet while the alcohol groups each consumed 95% of the liquid diet. Despite this difference, body weight and Quetelet index (weight/height2) decreased progressively in the order controls greater than regular drinkers greater than binge drinkers. Results from our study indicate that moderate, regular daily consumption of EtOH at 12% of calories causes a modest reduction in body weight and produces a coronary protective lipoprotein profile (increases HDL2/HDL3, increases apolipoprotein A-I/B, low LDL cholesterol). By contrast, when this same average weekly dose is concentrated in a binge cycle, unfavorable alterations in lipoprotein composition (increases LDL cholesterol, increases apolipoprotein B) and metabolism (decreases LCAT activity) occur along with weight loss and depletion of body fat. These studies point to the value of the squirrel monkey model in evaluating both favorable and pathophysiological effects of chronic EtOH intake.

Alcohol Drinking↗

PubMed1990

Sustained coronary-risk-factor reduction after gastric bypass for morbid obesity.

Lipids and clinical changes including diabetes and hypertension were monitored in morbidly obese patients after Roux-Y gastric bypass. Total cholesterol (Chol), high-density-lipoprotein (HDL) cholesterol, and triglycerides at 1 and at 5-7 y postoperatively in 33 patients and at 1 y in 23 patients (including apolipoproteins A-I and B) were compared with preoperative concentrations. Mean concentrations of Chol and both apolipoproteins were unchanged. Elevated serum triglycerides became normal, and reduced concentrations persisted at 5-7 y in men (p less than 0.025). HDL-cholesterol concentrations increased at 1 y (p less than 0.01) and remained higher at 5-7 y in women. Ratios of Chol to HDL cholesterol were lower at 1 y (p less than 0.01) in both men and women. Diabetes (9 patients) and hypertension (22 patients) also were reduced at 1 y (p less than 0.01) and remained lower at 5-7 y. A mean 61% of excess weight was lost in 1 y whereas a 12% weight gain occurred by 5-7 y. The beneficial changes in most coronary risk factors lasted 5-7 y after surgery.

Adult↗

PubMed1990

Body fat distribution and male/female differences in lipids and lipoproteins.

The role of body fat distribution, as assessed by the ratio of waist-to-hip circumferences (WHR), in statistically explaining differences in levels of lipoproteins between men and women was studied using data collected in 1985-1986 from employed adults (mean age, 40 years). As compared with the 415 women, the 709 men had higher mean levels of triglycerides (+38 mg/dl) and apolipoprotein B (+11 mg/dl) as well as lower mean levels of high density lipoprotein (HDL) cholesterol (-15 mg/dl) and apolipoprotein A-I (-19 mg/dl). Additionally, men were more overweight, consumed more alcohol, and exercised more frequently than women but were less likely to smoke cigarettes. Controlling for these characteristics, however, did not alter the differences in lipoprotein levels between men and women. In contrast, adjustment for WHR (which was greater among men) reduced the sex differences in levels of apolipoprotein B (by 98%), triglycerides (by 94%), HDL cholesterol (by 33%), and apolipoprotein A-I (by 21%). Similar results were obtained using analysis of covariance, stratification, or matching; at comparable levels of WHR, differences in lipid and lipoprotein levels between men and women were greatly reduced. Although these results are based on cross-sectional analyses of employed adults and need to be replicated in other populations, the findings emphasize the relative importance of body fat distribution. Whereas generalized obesity and body fat distribution are associated with lipid levels, fat distribution (or a characteristic influencing fat patterning) can be an important determinant of sex differences in levels of triglycerides, HDL cholesterol, and apolipoproteins B and A-I.

Adipose Tissue↗

PubMed1989

Risk factors and the anatomic distribution of coronary artery disease.

Differences in the importance of risk factors according to the anatomic location of coronary artery disease (CAD) were assessed in 4722 men and 1069 women who underwent arteriography. Examined characteristics included total and high-density lipoprotein (HDL)-cholesterol, triglycerides, obesity, smoking, alcohol consumption, diabetes, and hypertension. Of these risk factors, the ratio of total to HDL-cholesterol showed the highest correlation with the overall severity of CAD (r = 0.24, men; r = 0.38, women); in contrast, its relation to left main (LM) disease was much lower (r = 0.10, men; r = 0.08 women) than were correlations with stenotic disease in the left anterior descending, circumflex, and right coronary arteries. Other risk factors also showed weaker associations with LM disease than with stenoses in other vessels, and none was related to increased LM disease after controlling for disease in other vessels. For example, as compared with men who had no significant CAD, those with 1-, 2-, and 3-vessel disease had mean increases in total cholesterol of 12, 18, and 19 mg/dl, respectively. In contrast, after adjusting for disease in other vessels, LM disease (present in 293 men) was associated with only a 4 mg/dl increase in mean cholesterol levels (P = 0.20). These results indicate that the relation of risk factors to CAD differs according to the location of the stenotic disease, and that LM disease is poorly predicted by the standard risk factors.

Adult↗

PubMed1989

Cigarette smoking and non-fatal myocardial infarction in women: is the relation independent of coronary artery disease?

The relation of cigarette smoking to both coronary disease and non-fatal myocardial infarction was examined in a cross sectional study of 1053 women who underwent coronary arteriography. As compared with the 489 women who had never smoked cigarettes, ever-smokers (mean duration of smoking, 25 years) were 1.6 times as likely to have significant stenotic disease and were 1.9 times as likely to have suffered a myocardial infarction. These associations were strongest in women under 50 years of age, with odds ratios of 3.5 for coronary artery disease and 4.5 for myocardial infarction. Although the extent of stenotic disease and prior myocardial infarction were strongly associated, women who smoked cigarettes remained at increased risk of a myocardial infarction even after their increased coronary artery disease had been taken into account. For example, heavy smokers (greater than 30 pack-years) were 2.3 times as likely to have had a myocardial infarction as were non-smokers; controlling for the extent of stenotic disease (in addition to age and other risk factors) reduced the estimated relative risk to only 1.9. Stratified analyses showed that this increased risk for clinical disease among smokers was evident at all levels of occlusion, even among women with minimal stenotic disease. These results, collected at the time of arteriography, suggest that non-atherogenic mechanisms may be important in the aetiology of myocardial infarction among women who smoke cigarettes.

Coronary Artery Disease↗

PubMed1988

Black/white differences in risk factors for arteriographically documented coronary artery disease in men.

Although the leading cause of death among black men in the United States is coronary artery disease (CAD), risk factors have not been well documented in black populations. Therefore, possible racial differences in the relation of several characteristics to the extent of CAD were assessed in 4,722 white and 169 black men who underwent arteriography. Associations between an occlusion score (ranging from 0 to 300), reflecting the severity of CAD, and levels of total and high-density lipoprotein (HDL) cholesterol, triglycerides, cigarette smoking, alcohol intake, relative weight, systemic hypertension and diabetes mellitus were examined. Most risk factors were significantly related to the extent of CAD in both races, but lipid levels showed stronger associations with CAD among blacks: correlations between CAD and total cholesterol were 0.16 (whites) vs 0.29 (blacks) and associations with HDL cholesterol were -0.22 (whites) vs -0.49 (blacks). In addition, at adverse levels of certain risk factors, blacks had more extensive CAD than did whites: mean occlusion scores were 148 (whites) and 238 (blacks) at HDL cholesterol levels less than 30 mg/dl. As assessed by multiple linear regression, however, only triglyceride levels were differentially related to CAD between whites (beta = 0) and blacks (beta = 0.47), p less than 0.01 for racial contrast. These results document the importance of risk factors in black men and indicate black/white differences in the relation of triglycerides to CAD.

Adult↗

PubMed1988

Postmenopausal use of estrogen and occlusion of coronary arteries.

The degree of coronary artery occlusion was compared between users and nonusers of postmenopausal estrogen among 933 female patients undergoing angiography between the ages 50 and 75 years in the Milwaukee Cardiovascular Data Registry. Users (n = 154) had less occlusion than nonusers (n = 779), and a significant increase in occlusion scores with age was evident for nonusers (p less than 0.001) but not for users (p = 0.50). The age-adjusted odds ratios for use of postmenopausal estrogen among women with moderate and severe levels of occlusion of the coronary arteries were 0.59 (95% confidence interval, 0.48 to 0.73) and 0.37 (95% confidence interval, 0.29 to 0.46), respectively, which indicated a statistically significant, apparent protective effect of postmenopausal estrogen on coronary occlusion. This effect was independent of the type of menopause or other risk factors but not independent of high-density lipoprotein-cholesterol levels. Higher high-density lipoprotein-cholesterol levels among users may indicate a biologic mechanism by which postmenopausal estrogen use lowers the risk of coronary occlusion.

Aged↗

PubMed1988

Plasma lipoprotein alterations in squirrel monkeys (Saimiri sciureus) during ethanol administration and abstinence.

The time course of lipoprotein changes during ethanol (EtOH) consumption followed by abstinence was examined in 3 groups of male squirrel monkeys: 1) controls fed isocaloric liquid diet; 2) low EtOH monkeys given liquid diet with vodka substituted isocalorically for carbohydrate at 12% of calories; and 3) high EtOH animals fed diet plus vodka at 24% of calories. After 2 weeks, high EtOH monkeys showed significant elevations in total plasma cholesterol which continued to increase at 4 weeks and then declined at 8 weeks. These elevations were the result of increases in both low density (LDL)- and high density lipoprotein (HDL)-cholesterol. Low EtOH monkeys had a modest increase in total cholesterol throughout 8 weeks which was attributed to increments in HDL-cholesterol alone. During abstinence, total, HDL- and LDL-cholesterol concentrations decreased rapidly in the high EtOH group and were similar to control values after 4 days. HDL-cholesterol showed a more gradual decline in animals fed 12% EtOH while LDL-cholesterol remained low and not significantly different from controls. Liver function tests were normal for all animals. Our results indicate that low-dose EtOH favors a coronary protective lipoprotein profile (increases HDL, decreases LDL) in squirrel monkeys while the higher alcohol regimen causes both favorable and unfavorable alterations in plasma lipids which quickly revert to control levels during abstinence.

Animals↗

PubMed1988

Tranquilizer use before and after coronary bypass operation.

High rates of tranquilizer use in coronary disease have been previously reported. In patients being evaluated for coronary disease, tranquilizer use has been related to myocardial infarction, angina pectoris, neurotic traits, employment and the use of cardioactive and other medications. In this study, responses of 1046 male patients to a questionnaire assessing biological, psychological and social variables before and after coronary bypass surgery were related to tranquilizer use. The effect of CABG was to decrease tranquilizer use. Tranquilizer use prior to coronary bypass operations was related to neuroticism, myocardial infarction and taking cardiac and analgesic medication. Similar findings were noted after coronary bypass operations except that angina pectoris was added as a contributor to tranquilizer use. The multivariate analysis tended to confirm the univariate findings, except that neurotic traits did not make an independent contribution. These results indicate that in patients undergoing coronary evaluations, cardiac disease variables other than coronary atherosclerosis determine tranquilizer use. Neurotic traits play a secondary role. Relief of angina pectoris appears to be particularly important in reducing tranquilizer use. The finding of angina pectoris after coronary bypass operation may have special significance for the continuation of tranquilizer use.

Adaptation, Psychological↗

PubMed1988

Diabetes mellitus and arteriographically-documented coronary artery disease.

Diabetics are at increased risk for coronary heart disease even after accounting for other risk factors, and the impact of diabetes mellitus may be particularly strong among females and at adverse levels of other risk factors. Therefore, the independent relation of diabetes to arteriographically-documented coronary artery disease (CAD) was examined in 5620 patients (18% female) referred to two Milwaukee hospitals from 1972 to 1986. As assessed by questionnaire, the prevalence of diabetes mellitus among these patients was 8% (n = 466). Diabetics had increased CAD (assessed by the number and severity of stenoses) even after accounting for levels of total and high-density lipoprotein cholesterol, triglycerides, hypertension, obesity, smoking, and alcohol consumption. In addition, regression analyses indicated that as compared with nondiabetics, female diabetics tended to have a greater increase in CAD than did male diabetics (p = 0.06 for sex x diabetes interaction). Although adverse levels of other risk factors did not increase the association between diabetes and CAD, female diabetics who were using oral hypoglycemics or insulin showed almost a two-fold increase in CAD severity (p less than 0.01). Results suggest that the higher relative risk of coronary heart disease among female (vs male) diabetics may be due to a proportionately greater increase in atherosclerosis.

Adult↗

PubMed1988

Calcium intake and the relationship of dietary sodium and potassium to blood pressure.

Using First National Health and Nutrition Examination Survey (NHANES I) data, we studied the relationships of dietary sodium, potassium, and alcohol to blood pressure in relation to levels of dietary calcium intake. At low Ca intakes (less than 400 mg/d for men and less than 800 mg/d for women) the ratio of Na to K (Na:K) was significantly related to blood pressure (p less than 0.01) after controlling for age, body mass index (BMI), race, and gender. At higher Ca intakes neither Na:K nor any other nutrient (with the exception of alcohol) was related to either systolic or diastolic blood pressures. Na:K was more strongly related to blood pressure than either nutrient alone and low Ca intakes were necessary for the Na:K-blood pressure relationship to be evident. Interaction of these three dietary factors in relation to blood pressure was evident in all race and gender groups. Associations of age, BMI, gender, and alcohol with blood pressure were not affected by Ca levels.

Adolescent↗

PubMed1988

Relation of triglyceride levels to coronary artery disease: the Milwaukee Cardiovascular Data Registry.

Although levels of triglycerides have consistently shown a strong association with cardiovascular disease in both case-control and cohort studies, it remains controversial whether this relation exists independently of levels of cholesterol and other risk factors. The association of arteriographically documented coronary artery disease with plasma levels of triglycerides, total cholesterol, and high density lipoprotein (HDL) cholesterol was therefore examined in 5,216 white adults (81% were male) referred to two Milwaukee hospitals between 1972 and 1986. Elevated levels of triglycerides were related to the extent of coronary artery disease (estimated using the total number and severity of stenoses) in both sexes; this association existed independently of total cholesterol, age, obesity, hypertension, smoking, and alcohol consumption. In addition, the association between triglycerides and coronary artery occlusion was strongest at total cholesterol levels less than or equal to 250 mg/dl. However, both stratified and regression analyses indicated there was no residual association between triglyceride levels and occlusion after controlling for HDL cholesterol. (Levels of HDL cholesterol and triglycerides showed a moderate inverse association: r = -0.39 to -0.51.) These results indicate that the association between coronary artery occlusion and levels of triglycerides is indirect, and that the disparate findings of earlier studies may have resulted from not controlling for HDL cholesterol.

Aged↗

PubMed1988

Effect of ethanol dose on low density lipoproteins and high density lipoprotein subfractions.

Male squirrel monkeys were fed increasing caloric percentages (0, 12, 24, and 36%) of ethanol (ETOH) substituted isocalorically for carbohydrate as part of a chemically defined liquid diet to assess how alcohol dose modifies plasma lipoproteins and liver function. A separate group of primates was used to define the dose at which elevations in plasma apolipoprotein B first occurred and to measure plasma alcohol levels. ETOH caused a dose-related, linear increase in high density lipoprotein (HDL) cholesterol which was primarily the result of increments in coronary protective HDL2 cholesterol. HDL2 total mass (lipid + protein) followed the pattern of HDL2 cholesterol. Animals fed the 12% regimen had plasma ETOH levels of approximately 49 mg/dl, the lowest low density lipoprotein (LDL) cholesterol, and the highest HDL2/HDL3 cholesterol ratio. Significant elevations in apolipoprotein B first appeared at 18% ETOH while higher doses (24 and 36%) caused increases in LDL cholesterol and HDL3, reduced HDL2/HDL3 ratios, and plasma alcohol levels of 142 and 202 mg/dl, respectively. Liver function tests were normal for all animals. Our results indicate that while a moderate ETOH caloric intake (12%) produces an antiatherogenic lipoprotein profile (decreases LDL/HDL, increases HDL2/HDL3), any coronary protection afforded by continued increases in HDL2 at higher doses may be attenuated by concurrent atherogenic alterations (increases LDL cholesterol, increases apolipoprotein B).

Alcohol Drinking↗

PubMed1988

Chest pain and behavior in suspected coronary artery disease.

This study assessed behavioral activity, dietary and emotional variables among patient cohorts with angina pectoris, atypical chest pain, and no chest pain in whom coronary disease is suspected. Questionnaire responses of 3,899 employed male patients at the time of coronary arteriography were analyzed. Patients with angina pectoris had high levels of coronary-prone and neurotic attitudes, and fatigue variables including feeling unrested on awakening, easy fatiguability, reducing activity at work and arriving home tired. Atypical chest pain patients showed coronary-prone and neurotic attitudes similar to the angina pectoris group but had less coronary occlusion and lower levels of fatigue variables. Compared to the other groups, atypical chest pain patients were more likely to skip breakfast and showed a trend to eat fast. These findings suggest that including assessment of activity levels, fatiguability, eating behavior, neurotic traits and coronary-prone attitudes at time of coronary arteriography can have some limited value for patients with chest pain who may seek cardiac treatment but could benefit from alternative approaches.

Angina Pectoris↗