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Biomedical subjects

S L Syme

Publications and source records attributed to S L Syme.

At least 37 records · Page 2Linked to original sources
PubMed1992

Job strain and prevalence of hypertension in a biracial population of urban bus drivers.

OBJECTIVES: In this study we tested the association between occupational stress--as measured by job demands, decision latitude, and job strain--and hypertension in a population of 1396 Black and White bus drivers. METHODS: Height, weight, blood pressure, and medical history were assessed by physical exam. Drivers completed a questionnaire assessing their work schedules, personal habits, and self-perceptions about job demands and decision latitude. RESULTS: Univariate analyses revealed significant inverse associations; lower levels of job demands and job strain were associated with a higher prevalence of hypertension for Blacks and Whites. After 12 confounding variables were controlled for, the association between these two measures of occupational stress and hypertension became nonsignificant. Decision latitude was also not significantly associated with hypertension. CONCLUSIONS: Our findings are inconsistent with previous studies' findings of a positive association between job strain and chronic diseases. The difference in results may be explained by our incorporation of individuals' perceptions in the measurement of occupational stressors and our use of individuals from a single occupation with comparable job responsibilities and income, thus controlling for potential confounding by social class.

Adult↗
PubMed1992

Conceptual and methodological issues for behavioral pediatrics research.

Three prescriptions are made to improve behavioral pediatrics research: (1) Focus behavioral pediatrics on preventive research from environmental and social perspectives. (2) Ground research questions more extensively within a conceptual framework. (3) Enhance research quality with reliable, valid measurement. Conceptual and methodological improvements in research will facilitate integration of the multidisciplinary, multimethodological, and multitheoretical scope of behavioral pediatrics and further its contributions to science.

Behavioral Medicine↗
PubMed1991

Blood pressure in Mexican Americans, whites, and blacks. The Second National Health and Nutrition Examination Survey and the Hispanic Health and Nutrition Examination Survey.

Previous studies of Mexican Americans have shown mean diastolic and systolic blood pressures and prevalence rates of hypertension which are either lower than or similar to those for non-Hispanic whites despite the predominance of obesity in Mexican Americans. However, those results are based on restricted samples from California and Texas. Using data from the Second National Health and Nutrition Examination Survey (1976-1980) and the Hispanic Health and Nutrition Examination Survey (1982-1984), the authors examined ethnic differences in blood pressure and hypertension. Regression analyses, stratified by sex, were used to compare mean blood pressures and rates of hypertension in Mexican Americans with those for whites and blacks. Mean diastolic and systolic blood pressures, as well as the prevalence of hypertension, were lower in Mexican Americans than in non-Hispanic whites or in blacks, with whom they shared a remarkably similar risk profile. This effect was unchanged after adjustment for age, body mass index (weight (kg)/height (cm)2 x 100), and education, indicating that blood pressure differences between Mexican Americans, whites, and blacks were not explained by the established correlates of high blood pressure. There are several possible reasons for lower blood pressure in Mexican Americans, including genetic, life-style, and cultural factors.

Adult↗
PubMed1991

Hostility and coronary artery disease.

Studies of the association between type A behavior and coronary heart disease have yielded inconsistent findings. A possible explanation for these inconsistent findings is that type A behavior is simply a marker for other behaviors that are truly related to coronary heart disease. Hostility is one such behavior that has been found in several recent studies to predict coronary heart disease and coronary atherosclerosis; however, several other studies have found null results. In the present study, the predictive power of hostility was tested in a study population of hospitalized men (n = 118) and women (n = 40) scheduled for coronary angiography. Potential coronary risk behaviors were assessed in the angiography patients and they were given the type A Structured Interview. Hostility was measured with the Cook-Medley Hostility Inventory and the Behavior Pattern Hostility Index, a measure of hostility derived from the type A Structured Interview. No significant positive associations were found for either Cook-Medley hostility or behavior pattern hostility and coronary occlusion. This was true whether hostility or coronary occlusion was treated as a dichotomous variable or as a continuous variable. In fact, most of the observed associations were opposite to the predicted direction, although none was statistically significant. Replicating cutpoints of the Cook-Medley Hostility Inventory used in other studies that have reported positive associations with coronary heart disease also yielded null findings. The association between hostility and coronary occlusion was slightly modified by age and sex, but the interaction coefficients were not significant. The sample size yielded adequate statistical power to detect the hypothesized associations, and there was no evidence that selection bias, measurement error, or unexamined confounding accounted for the null findings. These results failed to confirm some earlier reports showing a positive association between hostility and coronary artery disease.

Age Factors↗
PubMed1991

Smoking, social support, and hassles in an urban African-American community.

BACKGROUND: Despite public health efforts, the prevalence of smoking among African Americans remains high. The determinants of smoking behavior in this population must be elucidated so that interventions can be better targeted and more effective. METHODS: As part of a prospective community intervention trial to reduce cancer mortality, we conducted a random household survey of 1137 African-American adults in San Francisco and Oakland between November 1985 and July 1986. The survey instrument included questions about social network characteristics, instrumental and emotional aspects of social support, smoking behavior, and stressors. RESULTS: The overall prevalence of smoking (41.9%) was higher than that reported in national surveys. Logistic models revealed that persons reporting high levels of stress, represented by an abbreviated hassles index, were more likely to smoke than those reporting less stress. Women with poor social networks were more likely to smoke (odds ratio = 3.1) than women with optimal networks; however, this relationship did not hold among men. Indeed, men lacking emotional support from friends or family were less likely to smoke (odds ratio = 0.5) than men receiving such support. No interaction between social support and hassles was observed. CONCLUSIONS: Stressful environments may contribute to high-risk smoking behavior among urban African Americans.

Black or African American↗
PubMed1990

Influence of race, tobacco use, and caffeine use on the relation between blood pressure and blood lead concentration.

A number of studies have suggested a small to moderate positive relation between blood pressure and blood lead concentration in males (2-4 mmHg/In(microgram/dl]. However, this 1986 study of San Francisco bus drivers suggests larger relations in black males (n = 132) for both systolic pressure (7.5 mmHg/In(microgram/dl] and diastolic pressure (4.7 mmHg/In(microgram/dl] at very low blood lead concentrations (2-21 micrograms/dl). This increase appears to result from negative confounding, particularly after taking into account tobacco use. Relations are even larger in blacks who infrequently use caffeine (16.7 and 10.4 mmHg/In(microgram/dl) for systolic and diastolic pressure, respectively). In contrast, a negative relation between systolic pressure and blood lead concentration (-5.7 mmHg/In(microgram/dl] is suggested in nonblack males (n = 117). These findings indicate that race, lead accumulation, and physiologic effects related to caffeine use (e.g., catecholamine effects) may interact to produce marked differences in effect on blood pressure.

Black or African American↗
PubMed1989

Prevalence of hypertension in bus drivers.

1. To test whether prevalence of hypertension was higher among these bus drivers than among employed individuals in general, drivers were compared to three groups: individuals from both a national and local health survey and individuals undergoing baseline health exams prior to employment as bus drivers. 2. After adjustment for age and race, hypertension rates for bus drivers were significantly greater than rates for the three comparison groups. 3. These findings support previous results from international studies of bus drivers suggesting that exposure to the occupation of driving a bus may carry increased health risk.

Adult↗
PubMed1988

Excess risk of sickness and disease in bus drivers: a review and synthesis of epidemiological studies.

In an extensive search of available literature, 22 epidemiological studies that have examined health risks of bus drivers were identified. These studies focus on three main disease categories: (1) cardiovascular disease, including hypertension, (2) gastrointestinal illnesses, including peptic ulcer and digestive problems, and (3) musculoskeletal problems including back and neck pain. The studies consistently report that bus drivers have higher raes of mortality, morbidity, and absence due to illness when compared to employees from a wide range of other occupational groups. Increased disease rates have been found for drivers regardless of the use of different research methodologies, measurement techniques and comparison groups. When evaluating the impact of bias on the estimates of risk, it appears likely that findings are conservative: strong systematic selective factors have probably favoured the elimination of those in poorer health both at the time of entry into and exit from the job of bus driving and other sources of bias have most likely caused underestimations of risk. Nevertheless, there remain questions that need careful assessment before firm conclusions can be made about whether increased disease rates result from driving a bus. Such questions, coupled with the consistent findings of heightened risk of disease, make urban bus drivers an appropriate and promising occupational group in which to study further the potential adverse effects of the work environment on employee health.

Cardiovascular Diseases↗
PubMed1988

Self-reported stressors and hypertension: evidence of an inverse association.

This paper presents an analysis of self-reported stressors and blood pressure in a population of 1,428 San Francisco bus drivers surveyed from 1983 to 1985 as part of an occupational health study. To test the hypothesis of a positive association between psychosocial stressors and hypertension, the authors derived a stressor index from a survey instrument that assessed subjects' appraisal of work-related problems. A logistic regression analysis revealed an unexpected inverse association between the stressor index and hypertension that remained significant after adjustment for 12 potential confounding variables (standardized odds ratio = 0.84, p = 0.038). An analysis restricted to the 1,040 normotensive subjects, with mean blood pressure level as the outcome variable, also yielded inverse findings. To assess whether the results were specific to blood pressure, the authors repeated the multiple logistic analysis for gastrointestinal, respiratory, and musculoskeletal problems. In contrast to the inverse association found for hypertension, highly significant positive associations were found between the stressor index and these health problems. When prevalence of disease was examined by level of stressor score, a significant inverse gradient was observed for hypertension and significant positive gradients were observed for gastrointestinal, respiratory, and musculoskeletal problems (p values less than 0.001). An etiologic implication of these findings is that there may be a direct inverse association between subjective appraisal of stressors and blood pressure. A methodological implication is that subjective appraisal of stressors by persons with heightened blood pressure may be an invalid measure of objective, verifiable stressors.

Blood Pressure↗
PubMed1988

Social connections and mortality from all causes and from cardiovascular disease: prospective evidence from eastern Finland.

The association between an a priori measure of social connections and five-year mortality from all causes, cardiovascular diseases (International Classification of Diseases, Eighth Revision (ICD-8) codes 390-458), and ischemic heart disease (ICD-8 codes 410-414) was studied in 13,301 men and women from eastern Finland who were first interviewed in 1972 or 1977. For men, there was a graded association between extent of social connections and mortality. In multivariate models with adjustment for age, smoking, serum cholesterol, mean weighted blood pressure, measures of prevalent illness, and other possible confounders, men who were in the two lowest quintiles of the social connections scale were at increased risk compared with those in the highest quintile (odds ratio (OR)all cause = 1.54, 95% confidence interval (CI) = 1.21-1.95; ORcardiovascular disease = 1.54, 95% CI = 1.11-2.13; ORischemic heart disease = 1.34, 95% CI = 0.94-1.90). No strong or consistent association was found for women. The association for men was modified by levels of blood pressure with the effect of low social connections greater at higher levels of blood pressure. In three separate analyses, there was no evidence for confounding or effect modification due to prevalent illness at baseline.

Adult↗
PubMed1988

Type A behavior pattern and health status after 22 years of follow-up in the Western Collaborative Group Study.

Type A/B behavior has been studied extensively as a risk factor for coronary heart disease. This study tests the hypothesis that Type A/B behavior is associated with ill health in general. All-cause mortality was examined in the original cohort of 3,154 men aged 39-59 years at baseline in the Western Collaborative Group Study in 1960-1961. Morbidity was examined in a group of 2,365 men aged 61-81 years who were surviving members of the cohort in 1982-1983 and who agreed to fill out a self-administered health status questionnaire. On the basis of these data, a three-level general morbidity index was constructed that included coronary heart disease and a number of other chronic conditions. Type A/B behavior was not significantly associated with all-cause mortality over the 22-year follow-up. However, among men 61-71 years of age, behavior type assessed at the baseline examination 22 years earlier (1960-1961) was positively associated with the morbidity index (p less than 0.001). Furthermore, behavior type and the morbidity index showed a dose-response association; extreme Type A personalities had the highest level of morbidity, while those with the fewest Type A characteristics had the lowest level of morbidity. This general pattern of association was not due to the presence of coronary heart disease or to any other particular disease condition in the morbidity index and did not change when an ordinal logistic regression model was used to control for other baseline risk variables. For the older men (aged 72-81 years), the pattern of association was similar but did not reach statistical significance. Thus, in a group of men over 60, a positive association was found between general morbidity status and Type A/B behavior measured over two decades earlier.

Aged↗
PubMed1988

Heightened risk of hypertension among black males: the masking effects of covariables.

This study examines the extent to which a set of 10 demographic, behavioral, and medical risk factors explain black/white differences in hypertension. Data are from a cross-sectional examination of San Francisco transit drivers aged 25-65 years surveyed during 1983-1985 as part of an occupational health study. The inherent restriction of the study population to bus drivers and the further restriction to males in this population (764 blacks and 224 whites) controlled for factors related to occupation and sex. Control of 10 additional potential risk factors, including age, education, body mass index, smoking, and intake of caffeine and alcohol was possible in the analytic phase of the study. The unadjusted prevalence of hypertension (systolic blood pressure greater than or equal to 140 mmHg, diastolic blood pressure greater than or equal to 90 mmHg, or current use of antihypertensive medications) was 36.1 per cent for black males compared with 30.8 per cent for white males. The greatest difference in prevalence was observed for black males aged 55-64 years, for whom the prevalence was 46 per cent higher than for white males the same age. Despite higher rates of hypertension, blacks in all age groups exhibited lower levels of most major risk factors for hypertension. As a result, the independent effect of race on hypertension was increased rather than attenuated when the 10 covariables were taken into account (odds ratio of 1.27 in the unadjusted analysis, increasing to 1.54 in the adjusted, multivariate analysis). That this set of risk factors did not explain the higher rates of hypertension among blacks suggests that racial differences may arise from as yet unrecognized environmental and/or individual factors. The results also indicate that the association between race and blood pressure may have been underestimated in past studies that have relied on unadjusted analyses, in which negative confounding or masking effects of covariables have not been considered.

Adult↗
PubMed1988

Blood pressure and blood lead concentration in bus drivers.

San Francisco bus drivers have an increased prevalence of hypertension. This study examined relationships between blood lead concentration and blood pressure in 342 drivers. The analysis reported in this study was limited to subjects not on treatment for hypertension (n = 288). Systolic and diastolic pressures varied from 102 to 173 mm Hg and from 61 to 105 mm Hg, respectively. The blood lead concentration varied from 2 to 15 micrograms/dL. The relationship between blood pressure and the logarithm of blood lead concentration was examined using multiple regression analysis. Covariates included age, body mass index, sex, race, and caffeine intake. The largest regression coefficient relating systolic blood pressure and blood lead concentration was 1.8 mm Hg/ln (micrograms/dL) [90% C. I., -1.6, 5.3]. The coefficient for diastolic blood pressure was 2.5 mm Hg/ln (micrograms/dL) [90% C. I., 0.1, 4.9]. These findings suggest effects of lead exposure at lower blood lead concentrations than those concentrations that have previously been linked with increases in blood pressure.

Adult↗
PubMed1988

Social epidemiology and the work environment.

A major theme in virtually all of Bertil Gardell's work is that the social and work environment affects health and well-being. This concern with the social environment has been a major influence in the development of a new area of research referred to as social epidemiology. In this area of work, difficulties are increasingly being recognized in identifying specific social factors in the environment toward which intervention programs can be directed. An approach to this complex problem is to focus attention on the "mini-environment" of the workplace. Research here has yielded several interesting hypotheses that may have important implications for studies of the larger environment. These hypotheses involve the concepts of control and participation, concepts that are central to all of Gardell's work.

Employment↗
PubMed1987

Prevalence of hypertension in bus drivers.

This paper reports the results of a cross-sectional study conducted to evaluate the prevalence of hypertension in 1500 black and white male bus drivers from a large urban transit system in the US. Data for this study were compiled from the files of an occupational health clinic which conducts biennial medical examinations for drivers' license renewal. To test whether prevalence of hypertension was higher among bus drivers than among employed individuals in general, drivers were compared to three groups: individuals from both a national and local health survey and individuals undergoing baseline health examinations prior to employment as bus drivers. After adjustment for age and race, hypertension rates for bus drivers were significantly greater than rates for each of the three comparison groups. These findings support previous results from international studies of bus drivers suggesting that exposure to the occupation of driving a bus may carry increased health risk. This research has expanded into an on-going study which has the goals of clarifying the extent of hypertension in bus drivers and identifying specific behavioural and occupational factors that may be responsible for increased risk of cardiovascular disease.

Adult↗
PubMed1987

Coronary artery disease: a sociocultural perspective.

A sociocultural perspective on biobehavioral factors is important both for studies of the cause of coronary heart disease and for efforts to prevent the disease. One-to-one programs are limited because coronary heart disease is so prevalent and because people have great difficulty in changing their behavior to lower their risk. Data are now available regarding several psychosocial risk factors that shed light on possible environmental influences. These factors include social mobility, stressful life events, type A behavior, and social support. These factors are now being studied in bus drivers to illustrate the ways in which sociocultural interventions can be developed to prevent disease.

Acculturation↗