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Biomedical subjects

A R Dyer

Publications and source records attributed to A R Dyer.

At least 37 records · Page 2Linked to original sources
PubMed1998

Association of dietary fish and n-3 fatty acid intake with hemostatic factors in the coronary artery risk development in young adults (CARDIA) study.

Hemostatic factors play an important role in the complications of ischemic heart and vessel disease. Dietary fats such as n-3 fatty acids have been shown to possibly influence hemostatic factors. However, most studies reporting an inverse association between cardiovascular disease and fish and n-3 fatty acid consumption used supplemental doses of fish oil or intakes exceeding the typical amount consumed by the US population. This report examined the associations of usual intakes of fish, linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid with fibrinogen, factor VII, factor VIII, and von Willebrand factor in the Coronary Artery Risk Development in Young Adults (CARDIA) Study. The analyses reported here included 1672 black and white men and women aged 24 to 42 years in 1992 to 1993. After adjustment for age, body mass index, diabetes, number of cigarettes smoked per day, race, and energy and alcohol consumption, no significant associations were observed between those who consumed no fish versus those who consumed the highest level of dietary fish with respect to fibrinogen, factor VIII, or von Willebrand factor for any race-sex group. Comparisons of tertile 1 versus tertile 3 for dietary linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid were also not significantly associated with fibrinogen, factor VII, factor VIII, or von Willebrand factor for any race-sex group. These data suggest that customary intakes of fish and n-3 fatty acids in populations that generally do not consume large amounts of these food items are not associated with these hemostatic factors.

Adult↗
PubMed1998

Juvenile dermatomyositis at diagnosis: clinical characteristics of 79 children.

OBJECTIVE: To evaluate demographic and clinical characteristics, duration of time between disease onset (date of first rash and/or weakness), and diagnosis/therapy, as well as socioeconomic status, of children with newly diagnosed juvenile dermatomyositis (JDM). METHODS: Structured telephone interview of families of a cohort of 79 children with JDM: interval between onset of symptoms to diagnosis, median of 3 months (range 0.5-20.0). RESULTS: At diagnosis, all the children had rash (100%) and proximal muscle weakness (100%); 58 (73%) had muscle pain; 51 (65%) fever; 35 (44%) dysphagia; 34 (43%) hoarseness; 29 (37%) abdominal pain; 28 (35%) arthritis; 18 (23%) calcinosis, and 10 (13%) melena. Muscle derived enzymes were normal in 10% of the children. Of the 43 children who had an electromyogram (EMG), 8 (19%) had normal results. Fifty-one children had a muscle biopsy; the results were normal/nondiagnostic in 10 (20%). Median time from disease onset to diagnosis was different between racial groups: Caucasians (n=59) 2.0 months: for minorities (n=20), 6.5 months, (p=0.0008). The median time from disease onset to therapy was: Caucasians. 3.0 months; minorities, 7.2 months (p=0.002). Report of calcinosis was associated with increased time to diagnosis and therapy (p=0.04). In the 33 children whose first symptom occurred in June-September, rash preceded or accompanied onset of muscle weakness in 83% (n=27). Ninety-one percent of the children were given steroid therapy and 9% received methotrexate as well. CONCLUSION: The results of an undirected site for muscle biopsy or EMG may not be diagnostic. Minority children had a longer interval between first JDM symptom and diagnosis/therapy than Caucasian children. Delay in diagnosis/therapy was associated with calcinosis.

Adolescent↗
PubMed1997

Fish consumption and the 30-year risk of fatal myocardial infarction.

BACKGROUND: Epidemiologic data on the possible benefit of eating fish to reduce the risk of coronary heart disease have been inconsistent. We used data from the Chicago Western Electric Study to examine the relation between base-line fish consumption and the 30-year risk of death from coronary heart disease. METHODS: The study participants were 1822 men who were 40 to 55 years old and free of cardiovascular disease at base line. Fish consumption, as determined from a detailed dietary history, was stratified (0, 1 to 17, 18 to 34, and > or = 35 g per day). Mortality from coronary heart disease, ascertained from death certificates, was classified as death from myocardial infarction (sudden or nonsudden) or death from other coronary causes. RESULTS: During 47,153 person-years of follow-up, there were 430 deaths from coronary heart disease; 293 were due to myocardial infarctions (196 were sudden, 94 were nonsudden, and 3 were not classifiable). Cox proportional-hazards regression showed that for men who consumed 35 g or more of fish daily as compared with those who consumed none, the relative risks of death from coronary heart disease and from sudden or nonsudden myocardial infarction were 0.62 (95 percent confidence interval, 0.40 to 0.94) and 0.56 (95 percent confidence interval, 0.33 to 0.93), respectively, with a graded relation between the relative risks and the strata of fish consumption (P for trend = 0.04 and 0.02, respectively). These findings were accounted for by the relation of fish consumption to nonsudden death from myocardial infarction (relative risk, 0.33; 95 percent confidence interval, 0.12 to 0.91; P for trend= 0.007). CONCLUSIONS: These data show an inverse association between fish consumption and death from coronary heart disease, especially nonsudden death from myocardial infarction.

Adult↗
PubMed1997

Baseline sodium-lithium countertransport and 6-year incidence of hypertension. The Gubbio Population Study.

BACKGROUND: Sodium-lithium countertransport (Na-Li CT) activity is high in persons with hypertension. This study investigated whether high Na-Li CT relates to development of hypertension. METHODS AND RESULTS: At the baseline visit of the Gubbio Population Study, 4210 people of the 5376 surveyed were 18 to 74 years old; of these, 1599 were hypertensive (systolic pressure > or = 140 mm Hg, or diastolic pressure > or = 90 mm Hg, or on antihypertensive drug therapy). Of the 2611 nonhypertensives, 302 did not have Na-Li CT measured and 580 did not participate in 6-year follow-up. This analysis, therefore, deals with data collected on 1729 men 18 to 74 years old and women 18 to 74 years old who at baseline were nonhypertensive and had Na-Li CT measurement. Compared with individuals who were nonhypertensive at baseline and follow-up, individuals with incident hypertension at follow-up (systolic pressure > or = 140 mm Hg, or diastolic pressure > or = 90 mm Hg, or on antihypertensive drug therapy) had higher baseline values of Na-Li CT, blood pressure, age, body mass index, plasma cholesterol, and alcohol intake (P < .05). Baseline Na-Li CT was positively associated (P < .05) with development of hypertension in quartile analysis, with highest incidence of hypertension among men and women with Na-Li CT in the highest quartile (for men, > or = 376 and for women, > or = 311 mumol Li-L red blood cells-1.h-1). In univariate logistic regression, incidence of hypertension was related to baseline value of Na-Li CT, blood pressure, age, body mass index, plasma cholesterol, and alcohol intake (P < .05). In multiple logistic regression analysis, individuals with baseline Na-Li CT higher by 127 mumol (pooled SD for men and women) had 1.23 times greater risk of incident hypertension with control for sex and baseline age, body mass index, systolic pressure, and other confounders (P < .001). CONCLUSIONS: Na-Li CT is a predictor of hypertension risk in adults.

Adolescent↗
PubMed1997

New-onset juvenile dermatomyositis: comparisons with a healthy cohort and children with juvenile rheumatoid arthritis.

OBJECTIVE: To determine, in a case-control study, if patients with new-onset juvenile dermatomyositis (juvenile DM) have increased symptoms prior to onset, exposure to certain environmental conditions, frequency of familial autoimmune diseases, or antibody titers, compared with 2 control groups. METHODS: A structured interview with the families of 80 children with juvenile DM, 40 children with juvenile rheumatoid arthritis (JRA), or 23 healthy children, from the same geographic area as the children with juvenile DM, was conducted. All children's sera were tested for antibody to Toxoplasma gondii, herpes simplex virus (HSV), or coxsackievirus B (CVB). RESULTS: A high proportion of children with juvenile DM had constitutional symptoms 3 months before the disease-onset date (P = 0.013 versus control children). Children with JRA had more relatives with rheumatoid arthritis (P = 0.0001) and pernicious anemia (P = 0.003) than did children with juvenile DM or healthy children. Among children < or =7 years of age, elevated enteroviral titers were more frequent in those with juvenile DM (81%) and in healthy controls (90%) than in those with JRA (64%), suggesting a common environmental exposure. Titers to T gondii, HSV, or CVB 1-6 were normal. CONCLUSION: Frequencies of familial autoimmune disease, exposure to environmental factors, or elevated antibody titers to T gondii, HSV, or CVB are not increased in juvenile DM. Children with juvenile DM do have symptoms of illness 3 months before the disease-onset date, and young patients have elevated enteroviral titers, as do young geographic controls.

Animals↗
PubMed1997

The ethics of human genetic intervention: a postmodern perspective.

Gene therapy for a particular disease like Parkinson's involves ethical principles worked out for other diseases. The major ethical issues for gene therapy (and the corresponding ethical principles) are safety (nonmalfeasance), efficacy (beneficence), informed consent (autonomy), and allocation of resources (justice). Yet genetic engineering (germ-line interventions or interventions to enhance human potentialities) raises emotions and fears that might cause resistance to gene therapies. Looking at these technologies in a postmodern perspective helps one to appreciate the issues at stake in social and cultural change with a new technology such as gene therapy. While "modern" technology and ethics have focused on the autonomy of the individual, we are beginning to see a lessening of such emphasis on individualism and autonomy and more emphasis on the health of the population. Such a social change could cause technologies about which society may currently be cautious (such as human genetic interventions) to become more acceptable or even expected.

Ethics, Medical↗
PubMed1997

A classification system to evaluate weight maintainers, gainers, and losers.

OBJECTIVES: To study natural weight changes and to develop a weight classification system that can identify weight maintainers, gainers, and losers. DESIGN/OUTCOME: A prospective, observational study in which weight changes over five annual measurements were evaluated. In the weight classification system used, changes greater than 5 lb defined weight maintenance, gain, or loss. SUBJECTS/SETTINGS: Subjects were healthy, normal-weight and over weight, men and women (mean age = 44.1 +/- 14.1 years) in the Relationships of Energy, Nutrition, and Obesity to Cardiovascular Disease Risk Study. Prospective data for 385 of the original 508 subjects for whom actual weights were available for each of the 5 years (1985 to 1990) were used to classify and characterize subjects by weight-change categories. STATISTICAL ANALYSES: Cross-tabulations (with chi 2 tests) and hterarchical log-linear analyses (with partial chi 2 tests) to examine the relationships of categorical variables; analyses of variance (with F tests) for continuous measures. RESULTS: Over the 4-year interval, 46% of subjects were classified as maintainers, 34% as gainers, and 20% as losers. Over shorter 1-year epochs, more subjects were maintainers (62%) and fewer subjects were gainers (22%) or losers (16%). Maintainers had fewer and smaller magnitudes of weight fluctuations and showed fewer deleterious changes in health risk factors than gainers. APPLICATIONS: Weight changes of greater than +/-5 lb can classify a person as a weight maintainer, or loser. Although annual weight changes were used in this study, a weight change of more than 5 lb between any two points in time may suggest nonmaintenance of weight or weight instability that needs further evaluation.

Adult↗
PubMed1997

One-hour postload plasma glucose and risks of fatal coronary heart disease and stroke among nondiabetic men and women: the Chicago Heart Association Detection Project in Industry (CHA) Study.

Associations of baseline one-hour postload plasma glucose with 22-year coronary heart disease, stroke, cardiovascular diseases, and all cause mortality were assessed in five age-specific cohorts of nondiabetic men and women from the Chicago Heart Association Detection Project in Industry: 10,269 men ages 18-39 years; 7993 men ages 40-59 years; 1240 men ages 60-74 years; 6319 women ages 40-59 years; and 932 women ages 60-74 years. Plasma glucose was determined one hour after a 50-gram oral glucose load. Cox regression analyses were used to control for age and other covariates. Generally, higher glucose was significantly associated with mortality from coronary heart disease, stroke, cardiovascular diseases, and all cause mortality in men and women. This large longitudinal study provides evidence that one-hour postload plasma glucose in the absence of clinical diabetes at baseline apparently is an independent risk factor for fatal coronary heart disease and stroke in middle-aged and older nondiabetic men and women, and also for cardiovascular diseases and for all cause mortality.

Adolescent↗
PubMed1997

Dietary vitamin C, beta-carotene and 30-year risk of stroke: results from the Western Electric Study.

The relations of dietary antioxidants vitamin C and beta-carotene to 30-year risk of stroke incidence and mortality were investigated prospectively in the Chicago Western Electric Study among 1,843 middle-aged men who remained free of cardiovascular disease through their second examination. Stroke mortality was ascertained from death certificates, and nonfatal stroke from records of the Health Care Financing Administration. During 46, 102 person-years of follow-up, 222 strokes occurred; 76 of them were fatal. After adjustment for age, systolic blood pressure, cigarette smoking, body mass index, serum cholesterol, total energy intake, alcohol consumption, and diabetes, relative risks (and 95% confidence intervals) for nonfatal and fatal strokes (n = 222) in highest versus lowest quartiles of dietary beta-carotene and vitamin C intake were 0.84 (0.57-1.24) and 0.71 (0.47-1.05), respectively. Generally similar results were observed for fatal strokes (n = 76). Although there was a modest decrease in risk of stroke with higher intake of beta-carotene and vitamin-C intake, these data do not provide definitive evidence that high intake of antioxidant vitamins decreases risk of stroke.

Adult↗
PubMed1997

Diabetes, asymptomatic hyperglycemia, and 22-year mortality in black and white men. The Chicago Heart Association Detection Project in Industry Study.

OBJECTIVE: To assess relationships of diabetes and asymptomatic hyperglycemia at baseline to the risk of cardiovascular disease (CVD) and all-cause (ALL) mortality in employed, white and black middle-aged men. RESEARCH DESIGN AND METHODS: A prospective cohort study of 11,554 white men and 666 black men between the ages 35 and 64 from 1967 to 1973 was conducted using data from the Chicago Heart Association (CHA) Detection Project in Industry 22-year mortality follow-up. cox proportional hazards models, adjusted fro age and other CVD risk factors, were used to estimate the relative risk (RR) and the 95% CI of mortality associated with baseline glycemic status. RESULTS: Age-adjusted baseline prevalence of clinical diabetes was similar in white (3.7%) and black (4.3%) men; asymptomatic hyperglycemia (glucose post-50-g load > or = 11.1 mmol/l) was present in 11.1% of whites and 7.8% of blacks. After controlling for age, lifestyle, and other CVD risk factors, mortality risk was increased among white men with clinical diabetes (CVD: RR 2.51, CI 2.08-3.02; ALL: RR 1.88, CI 1.63-2.17) and asymptomatic hyperglycemia (CVD: RR 1.18, CI 1.01-1.37; ALL: RR 1.24, CI 1.11-1.37), compared with men with postload glucose < 8.9 mmol/l. Risks were similarly, though nonsignificantly (owing to low statistical power), increased among black men with clinical diabetes (CVD: RR 1.60, CI 0.60-4.29; ALL: RR 1.78, CI 0.97-3.25) and asymptomatic hyperglycemia (CVD: RR 1.29, CI 0.61-2.72; ALL: RR 1.37, CI 0.85-2.20). CONCLUSIONS: Asymptomatic hyperglycemia and clinical diabetes appear to confer increased mortality risk in both white and black men. In addition, mortality risk is increased with increased severity of glycemia. These findings indicate the importance of applying efforts to reduce risk factors and prevent diabetes in both blacks and whites.

Administration, Oral↗
PubMed1996

Inverse relation of dietary protein markers with blood pressure. Findings for 10,020 men and women in the INTERSALT Study. INTERSALT Cooperative Research Group. INTERnational study of SALT and blood pressure.

BACKGROUND: The purpose of this study was to assess relations to blood pressure (BP) in individuals of markers of dietary protein in their 24-hour urine collections. METHODS AND RESULTS: INTERSALT (INTERnational study of SALT and blood pressure) was a cross-sectional study of 10020 men and women aged 20 to 59 years in 52 population-based samples in 32 countries worldwide, with quality-controlled standardized procedures and assessment of multiple possible confounders. Three measurements of dietary protein in 24-hour urine of each individual participant were studied: total nitrogen and urea as indexes of total protein intake, and sulfate as an index of sulfur-containing dietary amino acids. Repeat examination was performed in a random 8% of participants to assess reliability and to correct for regression-dilution bias. Significant independent inverse relationships were found between BP (systolic and diastolic) and both 24-hour urinary total nitrogen and urea nitrogen, with adjustment for age, sex, alcohol intake, body mass, and 24-hour urinary sodium, potassium, calcium, and magnesium. With adjustment for regression-dilution bias, it was estimated that systolic and diastolic BP were on average 3.0 and 2.5 mm Hg lower, respectively, for persons with dietary total protein intake 30% above the overall mean than for those whose dietary protein intake was 30% below the overall mean (12.94 versus 6.96 g/d urinary total nitrogen, equivalent to 81 versus 44 g/d dietary protein, respectively). For the association of these markers with diastolic BP, results were similar for younger (20- to 39-year-old) and older (40- to 59-year-old) persons and for women and men. For their relation to systolic BP, regression coefficients were larger both for those aged 40 to 59 years than for those aged 20 to 39 years and for women than for men. Nonsignificant inverse relations were recorded for urinary sulfate and BP. CONCLUSIONS: These INTERSALT findings lend support to the hypothesis that higher dietary protein intake has favorable influences on BP.

Adult↗
PubMed1996

Intersalt revisited: further analyses of 24 hour sodium excretion and blood pressure within and across populations. Intersalt Cooperative Research Group.

OBJECTIVES: To assess further the relation in Intersalt of 24 hour urinary sodium to blood pressure of individuals and populations, and the difference in blood pressure from young adulthood into middle age. DESIGN: Standardised cross sectional study within and across populations. SETTING: 52 population samples in 32 countries. SUBJECTS: 10,074 men and women aged 20-59. MAIN OUTCOME MEASURES: Association of sodium and blood pressure from within population and cross population multiple linear regression analyses with multivariate correction for regression dilution bias. Relation of sample median daily urinary sodium excretion to difference in blood pressure with age. RESULTS: In within population analyses (n = 10,074), individual 24 hour urinary sodium excretion higher by 100 mmol (for example, 170 v 70 mmol) was associated with systolic/diastolic blood pressure higher on average by 3/0 to 6/3 mm Hg (with and without body mass in analyses). Associations were larger at ages 40-59. In cross population analyses (n = 52), sample median 24 hour sodium excretion higher by 100 mmol was associated with median systolic/diastolic pressure higher on average by 5-7/2-4 mm Hg, and estimated mean difference in systolic/diastolic pressure at age 55 compared with age 25 greater by 10-11/6 mm Hg. CONCLUSIONS: The strong, positive association of urinary sodium with systolic pressure of individuals concurs with Intersalt cross population findings and results of other studies. Higher urinary sodium is also associated with substantially greater differences in blood pressure in middle age compared with young adulthood. These results support recommendations for reduction of high salt intake in populations for prevention and control of adverse blood pressure levels.

Adult↗
PubMed1996

Measures of adiposity and coronary heart disease mortality in the Chicago Western Electric Company Study.

Associations of body mass index (BMI), two measures of percent body fat derived from skinfolds, body weight adjusted for height, triceps and subscapular skinfolds, and their sum, with 22-year coronary heart disease (CHD) mortality were compared in 1707 white men ages 40-55 years at baseline (1958) and free of CHD and cancer in 1961 in the Western Electric Study. Because associations of adiposity measures with CHD mortality differed by length of follow-up, analyses were conducted separately for the first 14 years of follow-up and years 15 through 22. In Cox regression analyses, none of the adiposity measures was significantly related to CHD mortality for the first 14 years of follow-up. For years 15-22, all adiposity measures, except triceps skinfold, were significantly related with adjustment for age, as well as eight other covariates. These results indicate that a positive relation of adiposity to CHD risk may not become apparent until several years after the assessment of adiposity.

Adipose Tissue↗
PubMed1996

Sodium-lithium countertransport and blood pressure change over time: the Gubbio study.

Sodium-lithium countertransport activity in red blood cells relates to blood pressure (BP) and the prevalence of hypertension. This study investigated in adults the relation of sodium-lithium (Na-Li) countertransport to BP change from baseline to 6-year follow-up. In the Gubbio Population Study, 4210 men and women were 18 to 74 years old at baseline (1983-1986), and 3766 had a valid baseline Na-Li countertransport measurement; of these, 2729 were reexamined at 6 years of follow-up (1989-1992) and made up the study cohort. At baseline, data collection included age, height, weight, BP, pulse rate, drug treatment, alcohol intake, ratio of sodium to potassium in spot urine, plasma cholesterol, and Na-Li countertransport in red blood cells. At 6-year follow-up, data for age, BP, and drug treatment were collected as at baseline. From baseline, average BP declined for people on antihypertensive medication at follow-up and for those with baseline BP greater than or equal to 140/90 mm Hg (systolic/diastolic) and did not change or increased for the remaining participants. In quartile and correlation analyses controlled for sex, baseline BP, and antihypertensive treatment, BP change related significantly and directly to baseline Na-Li countertransport. In multiple linear regression analyses done for the entire cohort with control for other confounders, the regression coefficient of baseline Na-Li countertransport to BP change over time was positive and borderline significant. The Na-Li countertransport coefficient was positive and significant when analyses were done with the use of a categorical value of baseline Na-Li countertransport (quartile 4 and quartiles 1 through 3 combined). In both models, the Na-Li countertransport coefficient was the strongest for people with baseline BP greater than or equal to 120/80 mm Hg or for people with baseline age of 45 years or older. In conclusion, Na-Li countertransport significantly relates to BP change over time in adults.

Adolescent↗
PubMed1996

Fish consumption and stroke in men. 30-year findings of the Chicago Western Electric Study.

BACKGROUND AND PURPOSE: Evidence of a relationship of fish intake to stroke incidence or mortality is weak. This report examines the association of fish consumption with stroke. METHODS: A cohort of 2107 men aged 40 to 55 years from the Chicago Western Electric Study who were free of coronary heart disease and stroke through their first annual reexamination was investigated in relation to baseline fish intake and 30-year risk of fatal and nonfatal stroke. Data on baseline fish intake, categorized into four levels (> or = 35 g/d, 18 to 34 g/d, 1 to 17 g/d, and 0 g/d), were available for 1847 men. Average values of macronutrients and micronutrients from the first two examinations and major coronary and stroke risk factors were assessed in relation to fish consumption. Stroke mortality was ascertained from death certificates and nonfatal stroke from records of the Health Care Financing Administration. RESULTS: During 46,426 person-years of follow-up, 76 stroke deaths occurred. Men consuming > or = 35 g/d of fish (highest level) had a higher age-adjusted death rate from stroke (23.5 per 10,000 person-years) than men in the three other categories of fish consumption. Based on a Cox proportional hazards regression model with adjustment for age, systolic blood pressure, cigarette smoking, serum cholesterol level, diabetes, electrocardiographic abnormalities, and table salt use, hazards ratios (and 95% confidence intervals) for fish consumers compared with nonconsumers were 1.34 (0.53 to 3.41) for > or = 35 g/d, 0.96 (0.41 to 2.21) for 18 to 34 g/d, and 1.00 (0.43 to 2.33) for 1 to 17 g/d. Age-adjusted and multivariate analyses for fatal and nonfatal strokes (n = 222) yielded similar results. CONCLUSIONS: With stroke rates highest in the subgroup reporting highest fish intake, these data do not support the hypothesis of an inverse association of fish consumption with strokes.

Adult↗