Risk factors for premature myocardial infarction: a matched case-control study

Background: Myocardial infarction in young age is increasing. Identifying risk factors could be important for health promotion. We studied classic atherosclerotic risk factors in premature myocardial infarction. Methods: In this matched case-control study, which was conducted from 2005 to 2007 in Birjand County, the east of Iran, atherosclerotic risk factors (hyperten-sion, family history of coronary artery diseases, obesity, diabetes mellitus, dyslipidemia) of 98 patients affected by acute myocardial infarction aged under 50 years were compared with that of 98 healthy neighborhood controls. Results: Mean levels of cholesterol, triglyceride, low-density lipoprotein, as well as systolic blood pressure and body mass index were significantly higher in cases than in controls. There was a positive association between coronary artery disease at younger age and dyslipidemia OR=2.8 [95% CI: 1.5, 5.2], smoking OR=6.4 [95% CI: 3.0, 13.5], systolic hypertension OR=3.1 [95% CI: 1.5, 6.3], family history of coronary artery diseases OR=10.9 [95% CI: 3.2, 37.9] and diabetes OR=2.5 [95% CI: 1.04, 6.2]. Conclusion: Smoking, systolic hypertension and dyslipidemia were the most common risk factors among patients with premature myocardial infarction.     

Serum C-reactive protein and fibrinogen concentrations and self-reported angina pectoris and myocardial infarction: findings from National Health and Nutrition Examination Survey III

C-reactive protein may predict the risk of cardiovascular disease, but its association with angina pectoris in the general population has not been clearly established, however. We used data from National Health and Nutrition Examination Survey III conducted from 1988-1994 to examine the associations between serum C-reactive protein and plasma fibrinogen concentrations and self-reported angina pectoris and myocardial infarction among 7,948 U.S. men and women aged 40 years and older. C-reactive protein and fibrinogen concentrations were moderately correlated (r = 0.43). After adjustment for age, sex, race or ethnicity, education, smoking status, systolic blood pressure, serum cholesterol, high-density lipoprotein cholesterol, history of diabetes mellitus, body mass index, and physical activity, fibrinogen (but not C-reactive protein) concentration was significantly associated with self-reported angina pectoris. Neither fibrinogen or C-reactive protein concentrations were significantly associated with angina pectoris when entered in the model simultaneously. C-reactive protein and fibrinogen concentrations were positively associated with myocardial infarction when entered separately into models, but only C-reactive protein concentration was significantly associated with myocardial infarction when both variables were entered simultaneously. These cross-sectional data showed a significant positive association between C-reactive protein concentration and myocardial infarction but not self-reported angina pectoris in the U.S. population.     

Predictors of successful, self-reported lifestyle changes in a defined middle-aged population: the Soderakra Cardiovascular Risk Factor Study, Sweden

AIMS: It is well established that the main cause of the development of cardiovascular disease can be found in unhealthy lifestyle habits. In our study, we wanted to explore the long-term predictors of self-reported lifestyle changes in a middle-aged population after screening for cardiovascular risk factors 10 years earlier. METHODS: We conducted a 10-year follow-up telephone interview on self-reported lifestyle changes in a rural population in south-eastern Sweden, after a cardiovascular screening programme. The population comprised 90% of all inhabitants (n=705) aged 40-59 years at baseline, and 90% of these (n=629) were reached for the telephone interview. RESULTS: When multivariate logistic regression was used, a higher success rate for lifestyle changes was independently associated with female gender (odds ratio (OR)=1.56, 95% confidence interval (CI) 1.11-2.18). When stratified for gender, significant predictors for success in men were prevalent cardiovascular risk conditions (OR=4.77, 95% CI 2.18-10.5; p<0.001) and previous myocardial infarction (OR=22.8, 95% CI 4.73-110; p<0.001) at baseline. For women, elevated blood pressure (> or = 160 and/or > or = 90 mmHg) measured at baseline (OR=1.84, 95% CI 1.12-3.02; p=0.016) was significantly associated with successful lifestyle changes. Smoking at baseline was also associated with significant success: OR=3.36 (95% CI:2.05-5.51; p<0.001) and OR=1.81 (95% CI 1.11-2.95; p=0.017) for men and women, respectively. CONCLUSIONS: Female gender was associated with significant improvements in self-reported lifestyle changes. Furthermore, smoking, a medical history of diabetes, hypertension, angina pectoris or myocardial infarction at baseline predicted success in lifestyle change in this 10-year follow-up study.     

Family history of coronary heart disease, a strong risk factor for myocardial infarction interacting with other cardiovascular risk factors: results from the Stockholm Heart Epidemiology Program (SHEEP)

We explored the relation between family history of coronary heart disease and the risk of myocardial infarction in a case-control study of subjects, 45 to 70 years of age, living in Stockholm, Sweden. Our cases comprised 1091 male and 531 female first-time acute myocardial infarction patients who had survived at least 28 days after their infarction. Referents were randomly selected from the population from which the cases were derived. The adjusted odds ratio (OR) of myocardial infarction was 2.0 (95% confidence interval [CI] = 1.6-2.6) for men reporting > or = 1 affected parent or sibling, compared with men with no family history of coronary heart disease, and 3.4 (95% CI = 2.1-5.9) for those reporting > or = 2 affected parents or siblings. The corresponding OR for women were 2.1 (95% CI = 1.5-3.0) and 4.4 (95% CI = 2.4-8.1). We found evidence for synergistic interactions in women exposed to family history of coronary heart disease in combination with current smoking and with a high quotient between low-density lipoprotein and high-density lipoprotein cholesterol (>4.0), respectively, which yielded adjusted synergy index scores of 2.9 (95% CI = 1.2-7.2) and 3.8 (95% CI = 1.5-9.7), respectively. Similarly, in men we found evidence for interaction for the co-exposure of family history of coronary heart disease and diabetes mellitus. Our study shows that family history of coronary heart disease is not only a strong risk factor for myocardial infarction in both sexes, but that its effect is synergistic with other cardiovascular risk factors as well.     

Role of age and sex in short-term and long term mortality after a first Q wave myocardial infarction

STUDY OBJECTIVE: The objective of this study was to analyse whether the risk of death within 28 days and three years after a first Q wave myocardial infarction was higher in hospitalised women than in men. DESIGN: Follow up study. PATIENTS AND SETTING: All consecutive first Q wave myocardial infarction patients aged 25 to 74 years (447 women and 2322 men) admitted to a tertiary hospital in Gerona, Spain, from 1978 to 1997 were registered and followed up for three years. MAIN RESULTS: Women were older, presented more comorbidity and developed more severe myocardial infarctions than men. A significant interaction was found between sex and age. Women aged 65-74 had higher early mortality risk than men of the same age (OR 1.62; 95% CI 1.01, 2.66) after adjusting for age, comorbidity and acute complications including heart failure. Women under 65 tended to be at lower risk of early mortality than men (0.45 (95% CI 0.19, 1.04). Three year mortality of 28 day survivors did not differ between sexes. CONCLUSIONS: These data support the idea that the higher 28 day mortality in hospitalised women with a first Q wave myocardial infarction is mainly attributable to the large number of patients aged 65 to 74 years in whom the risk is higher than that in men. Women under 65 with myocardial infarction do not seem to be a special group of risk.     

Risk-factor profile for the incidence of subarachnoid and intracerebral haemorrhage, cerebral infarction, and unspecified stroke during 21 years' follow-up in men

AIMS: To study the risk-factor profile for the incidence of non-fatal and fatal stroke among middle-aged men according to the stroke subtypes subarachnoid or intracerebral haemorrhage, cerebral infarction, and unspecified stroke. METHODS: The study design is a prospective cohort study. A total of 16,209 men aged 40-49 years resident in Oslo were screened for cardiovascular disease risk factors in 1972-73. Of these, 14,403 men had no cardiovascular symptoms or diseases or diabetes. The incidence of stroke after 21 years of follow-up of all men was extracted from hospital records and linkage to Statistics Norway. RESULTS: A total of 429 non-fatal and 107 fatal stroke events were registered. Case fatality within 28 days (number and percentage of cases) was 51% (41, 7.7%) for subarachnoid haemorrhage, 39% (67, 12.6%) for cerebral haemorrhage, 10% (246, 46.3%) for cerebral infarct, and 19% (177, 33.4%) for unspecified stroke. Risk of stroke (not subarachnoid haemorrhage) increased with the presence of symptoms or a history of cardiovascular disease or diabetes. In multivariate analysis of men without CVD or diabetes, high blood pressure was a risk factor for all subtypes of stroke; furthermore, daily smoking was a risk factor for all subtypes except subarachnoid haemorrhage. Serum cholesterol and glucose concentrations and height (inverse association) were independently associated with cerebral infarction. Smoking was a significantly stronger predictor of fatal than non-fatal events. CONCLUSIONS: The risk-factor profile differed according to the underlying subtype of stroke. Cerebral infarction clearly shared with myocardial infarction the classical risk factors, including non-fasting glucose concentration.     

A population-based case-control study of temporal arteritis: evidence for an association between temporal arteritis and degenerative vascular disease?

The first population-based incident case-control study of temporal arteritis (TA) in the US was conducted using the unique data resources of the Rochester Epidemiology Project. During the period 1950-1985, 88 newly diagnosed cases of biopsy-proven TA were identified among residents of Olmsted County, Minnesota. Cases were each matched to four Olmsted County community controls on age, sex and duration of community medical record. Odds ratios (OR) were calculated for marital status, education, Quetelet index, pregnancy, age at menopause, thyroid disease, diabetes, smoking, hypertension, angina, myocardial infarction, peripheral vascular disease, and stroke. Multivariable conditional logistic regression analysis identified statistically significant adjusted OR for smoking (2.3, 95% CI = 1.3-4.1). Elevated ORs which were not statistically significant were noted for angina, myocardial infarction, and peripheral vascular disease. These data suggest that TA and arteriosclerosis may share a common causal pathway. Alternatively, histopathological misclassification of temporal artery biopsies may have resulted in the observed association. Due to the limited power of this population-based study, multicentre collaboration should be encouraged to more precisely define the epidemiology of TA.     

Shiftwork and myocardial infarction: a case-control study

OBJECTIVES: Previous studies have indicated an association between shiftwork and coronary heart disease. The increased risk could be due to job strain, which could act as a mediator of disease. There is also a possibility that interaction between shiftwork and job strain could occur that may induce or modify the development of disease. We conducted this study to explore the relation between shiftwork, job strain, and myocardial infarction. METHODS: 2006 cases with acute first time myocardial infarction were compared with 2642 controls without symptoms of myocardial infarction, and obtained from the same population that gave rise to the cases (population based case-control study). RESULTS: Myocardial infarction risk was associated with shiftwork both in men (odds ratio (OR) 1.3, 95% confidence interval (95% CI) 1.1 to 1.6) and women (OR 1.3, 95% CI 0.9 to 1.8). In the age group 45-55, the relative risk was 1.6 in men and 3.0 in women. The results cannot be explained by job strain, age, job education level, or smoking. No interaction was found between shiftwork and job strain. CONCLUSIONS: The findings indicate that shiftwork is associated with myocardial infarction in both men and women. The mechanism is unclear, but the relation cannot be explained by job strain, smoking, or job education level.

 

     

Exposure to urban nitrogen dioxide pollution and the risk of myocardial infarction

OBJECTIVES: This study attempted to determine whether long-term exposure to nitrogen dioxide (NO2), an indicator of motor vehicle exhaust, increases the risk of myocardial infarction (MI). METHODS: A population-based case-control study was conducted among men aged 25-64 years and residing in Kaunas, Lithuania. The study included all cases of first-time myocardial infarction in 1997-2000. Interviews with patients treated in hospitals elicited information on smoking and other risk factors, including residential histories. A high response rate (77.4%) resulted in 448 cases and 1777 controls. Nitrogen dioxide (NO2) was selected for analysis as an indicator of traffic-related air pollution. The annual air pollution levels were estimated for the residential districts; thereafter the data were linked to the home addresses of the cases and controls. RESULTS: After adjustment for age, education, smoking, blood pressure, body mass index, marital status, and psychological stress, the risk of myocardial infarction was higher for the men exposed to medium [odds ratio (OR) 1.43, 95% confidence interval (95% CI) 1.04-1.96] and high (OR 1.43, 95% CI 1.07-1.92) NO2 levels. The data suggested a stronger association among 55- to 64-year-old men. The risk of myocardial infarction increased by 17% among the 25- to 64-year-old men (OR 1.17, 95% CI 1.01-1.35) and by 34% among those aged 55-64 years (OR 1.34, 95% CI 1.08-1.67) from the first to the third tertile of NO2 exposure. CONCLUSIONS: The results indicate that urban NO2 pollution may increase the risk of myocardial infarction and that vehicle emissions may be of particular importance.     

Prevention of Coronary Heart Disease through Treatment of Infection with Chlamydia Pneumoniae? Estimation of Possible Effectiveness and Costs

Evidence has been accumulating for a link between Chlamydia pneumoniae and coronary heart disease (CHD). A spreadsheet model was used to estimate the impact of different strategies for screening and treating C. pneumoniae on the incidence of myocardial infarction and cardiac mortality over a 1-year post-intervention period. It was found that screening would potentially be most cost-effective in men aged over 35 with a history of myocardial infarction (around £2,000 per life-year saved). Cost-effectiveness would be inferior in those with established heart disease but no history of myocardial infarction (MI), and poor for people at elevated risk of CHD. If causality of the association were proven, the cost-effectiveness of treating C. pneumoniae in post-MI patients would compare favourably with, for example, statins for treating hypercholesterolaemia.     

Diabetes mellitus as a contributor to the risk of acute myocardial infarction

The risk of nonfatal acute myocardial infarction (AMI) has been studied in relation to diabetes and other risk factors, combining data from three Italian case-control studies including 1,737 cases with nonfatal AMI and 2,317 controls in hospital for acute diseases unrelated to AMI risk factors. The multivariate odds ratio (OR) of AMI for diabetes was 2.3 (95% confidence interval, 1.8-2.9); the association with AMI risk was apparently stronger in patients diagnosed with diabetes when aged <40 years (OR 2.9), and in women (OR 4.4). When the combined effect of diabetes and other known risk factors on the risk of AMI was considered, compared to nondiabetic subjects with each factor at the lowest risk level, the OR for diabetic subjects was 4.7 in smokers, 2.8 in heavy coffee drinkers, 2.7 in those with higher body mass index, 3.4 in patients with high cholesterol levels, 3.3, 4.3, and 2.7 for diabetic subjects with history of hyperlipidemia, hypertension, and obesity, respectively, and 4.3 for those with a family history of AMI in first degree relatives. The association of each risk factor was much stronger in diabetic women. Preventive measures to reduce the prevalence of each additional risk factors in diabetic subjects could led to a substantial reduction of risk of AMI.     

Prevalence of peripheral arterial disease: persistence of excess risk in former smokers

Objective: To determine the age-standardised prevalence of peripheral arterial disease (PAD) and associated risk factors, particularly smoking.
Method: Design: Cross-sectional survey of a randomly selected population. Setting: Metropolitan area of Perth, Western Australia. Participants: Men aged between 65–83 years.
Results: The adjusted response fraction was 77.2%. Of 4,470 men assessed, 744 were identified as having PAD by the Edinburgh Claudication Questionnaire and/or the ankle-brachial index of systolic blood pressure, yielding an age-standardised prevalence of PAD of 15.6% (95% confidence intervals (CI): 14.5%, 16.6%). The main risk factors identified in univariate analyses were increasing age, smoking — current (OR=3.9, 95% CI 2.9–5.1) or former (OR=2.0, 95% CI 1.6–2.4), physical inactivity (OR=1.4, 95% CI 1.2–1.7), a history of angina (OR=2.2, 95% CI 1.8–2.7) and diabetes mellitus (OR=2.1, 95% CI 1.7–2.6). The multivariate analysis showed that the highest relative risk associated with PAD was current smoking of 25 or more cigarettes daily (OR=7.3, 95% CI 4.2–12.8). In this population, 32% of PAD was attributable to current smoking and a further 40% was attributable to past smoking by men who did not smoke currently.
Conclusions: This large observational study shows that PAD is relatively common in older, urban Australian men. In contrast with its relationship to coronary disease and stroke, previous smoking appears to have a long legacy of increased risk of PAD.
Implications: This research emphasises the importance of smoking as a preventable cause of PAD.     

Dietary glycemic index, dietary glycemic load, and cardiovascular disease in middle-aged and older Swedish men

BACKGROUND: In women, dietary glycemic index (GI) and dietary glycemic load (GL) have been associated with cardiovascular disease; in men, however, the evidence for an association is weaker. OBJECTIVE: We tested the hypothesis that men consuming diets high in GI or GL have a greater risk of cardiovascular disease. DESIGN: At baseline, we assessed dietary GI and dietary GL by using food-frequency questionnaires in 36 246 Swedish men aged 45-79 y without diabetes or prior cardiovascular disease. Participants were followed through inpatient, cause-of-death, and death registries from 1 January 1998 until 31 December 2003 for myocardial infarction, ischemic stroke, hemorrhagic stroke, and cardiovascular mortality and until 31 December 2005 for all-cause mortality. We used Cox models with age as the time scale to estimate relative risks adjusted for cigarette smoking, body mass index, physical activity, demographic characteristics, and nutritional factors. RESULTS: Dietary GI and dietary GL were not associated with myocardial infarction (n = 1324), ischemic stroke (n = 692), cardiovascular mortality (n = 785), or all-cause mortality (n = 2959). Dietary GL was associated with hemorrhagic stroke [n = 165; relative risk = 1.44 comparing extreme quartiles (95% CI: 0.91, 2.27); P for trend = 0.047]. CONCLUSIONS: Dietary GI and dietary GL were not associated with ischemic cardiovascular disease or mortality, but dietary GL was associated with a greater risk of hemorrhagic stroke. Discrepancies between these findings and those of previous studies may be due to variations in the associations by sex or to differences in dietary contributions to GI and GL.     

Prevalence of peripheral arterial disease: persistence of excess risk in former smokers

OBJECTIVE: To determine the age-standardised prevalence of peripheral arterial disease (PAD) and associated risk factors, particularly smoking. METHOD: Design: Cross-sectional survey of a randomly selected population. Setting: Metropolitan area of Perth, Western Australia. Participants: Men aged between 65-83 years. RESULTS: The adjusted response traction was 77.2%. Of 4,470 men assessed, 744 were identified as having PAD by the Edinburgh Claudication Questionnaire and/ or the ankle-brachial index of systolic blood pressure, yielding an age-standardised prevalence of PAD of 15.6% (95% confidence intervals (CI): 14.5%: 16.6%). The main risk factors identified in univariate analyses were increasing age, smoking-current (OR = 3.9, 95% CI 2.9-5.1) or former (OR = 2.0, 95% CI 1.6-2.4), physical inactivity (OR = 1.4, 95% CI 1.2-1.7), a history of angina (OR = 2.2, 95% Cl 1.8-2.7) and diabetes mellitus (OR = 2.1, 95% Cl 1.7-2.6). The multivariate analysis showed that the highest relative risk associated with PAD was current smoking of 25 or more cigarettes daily (OR = 7.3, 95% Cl 4.2-12.8). In this population, 32% of PAD was attributable to current smoking and a further 40% was attributable to past smoking by men who did not smoke currently. CONCLUSIONS: This large observational study shows that PAD is relatively common in older, urban Australian men. In contrast with its relationship to coronary disease and stroke, previous smoking appears to have a long legacy of increased risk of PAD. IMPLICATIONS: This research emphasises the importance of smoking as a preventable cause of PAD.     

Tobacco smoking and acute myocardial infarction in young adults: a population-based case-control study

OBJECTIVE: To evaluate the effect of tobacco smoking on the risk of non-fatal acute myocardial infarction in young adults (< or = 45 years), and whether there is modification of this effect by sex. METHODS: We conducted a population-based case-control study with 329 incident acute myocardial infarction cases (42 women; 287 men), consecutively admitted to the Cardiology department of hospitals in Porto, Portugal, and 778 controls (486 women; 292 men), selected within the non-institutionalized Porto population, during 2001-2003. Odds ratios and 95% confidence intervals (OR, 95%CI) were calculated using unconditional logistic regression. RESULTS: The prevalence of current smoking was 80.8% in male cases and 53.8% in male controls (OR=3.63, 95%CI: 2.50, 5.27) and 59.5% of female cases were smokers compared to 35.8% of controls (OR=2.64, 95%CI: 1.39, 5.02). No interaction was found between current smoking and sex on myocardial infarction risk (p=0.401). A dose-effect response was present, the odds favoring myocardial infarction reaching an eight-fold increase for those that smoked > 25 cigarettes/day compared to never smokers. The risk estimate for former smokers was similar to never smokers. CONCLUSIONS: Tobacco smoking is an important independent risk factor for acute myocardial infarction in young adults, with similar strength of association for both sexes.     

Extending the public health impact of screening for diabetes in high-risk populations: opportunities in American Indian communities.

OBJECTIVE: To assess trends in diabetes screening among American Indian adults and identify opportunities to extend blood glucose screening to those at risk for undiagnosed diabetes and prediabetes. METHODS: In 1999, 2001, and 2003, approximately 1,000 American Indian adults aged 18 years and older living on or near the seven reservations in Montana were interviewed through telephone surveys. RESULTS: Of respondents without diagnosed diabetes, the proportion who recalled blood glucose screening for diabetes within the past 3 years increased from 68 percent in 1999 to 78 percent in 2003. Between 1999 and 2003, screening increased among men (64%-75%), women (71%-80%), those aged 18-44 years (64%-72%), and those aged 45 years and older (76%-84%). Factors independently associated with screening included age more than 45 years, family history of diabetes, and a history of high cholesterol. Current smokers were less likely to report screening compared to nonsmokers. Gender, obesity, and a history of high blood pressure were not associated with screening. CONCLUSIONS: Although self-reported diabetes screening increased over a 5-year period among Indians in Montana, additional groups who could benefit from screening include younger and obese individuals, and those with hypertension.     

Risk factors for non-fatal acute myocardial infarction in Italian women

BACKGROUND: We analyzed the relation between selected lifestyles and diseases and the risk of non-fatal acute myocardial infarction (AMI) in women in Northern Italy. METHODS: We used a combined data set from three case-control studies, including 558 cases and 1,044 hospital controls. RESULTS: The strongest risk factor for AMI was smoking, the odds ratio (OR) being 4.0 in current smokers (11.6 for > or = 5 cigarettes/day). Other risk factors were diabetes (OR 4.4), hypertension (OR 3.3), hyperlipidemia (OR 1.6), and family history of AMI (OR 2.1). Moderate alcohol drinking was protective (OR 0.8 for < 2 drinks/day) compared to non-drinkers, and heavy coffee drinking non-significantly increased the risk (OR 1.4 for >3 cups/day). Inverse association was found with fish (OR 0.7 for >1 portion/week), vegetables (0.7 for > or = 10 portions/week), and fruit (OR 0.6 for > or = 14 portions/week), while meat, whole-grain, and diary products were unrelated. Smoking effect was stronger in combination with diabetes (OR 27.7), hypertension (OR 15.7), hyperlipidemia (OR 6.3), family history of AMI (OR 8.7), and heavy coffee drinking (OR 5.7). CONCLUSIONS: The strongest risk factor for AMI was smoking, responsible of about 37% of cases, followed by diabetes, hypertension, hyperlipidemia, family history of AMI. Avoidance of smoking and increasing fish, vegetables, and fruit would reduce AMI risk of about 50%.     

Fish and shellfish consumption in relation to death from myocardial infarction among men in Shanghai, China.

Between 1986 and 1989, 18,244 men aged 45-64 years in Shanghai, China, participated in a prospective study of diet and cancer. All participants completed an in-person, structured interview and provided blood and urine samples. As of September 1, 1998, 113 deaths from acute myocardial infarction were identified. After analyses were adjusted for age, total energy intake, and known cardiovascular disease risk factors, men who consumed >or=200 g of fish/shellfish per week had a relative risk of 0.41 (95% confidence interval: 0.22, 0.78) for fatal acute myocardial infarction compared with men consuming <50 g per week. Similarly, dietary intake of n-3 fatty acids derived from seafood also was significantly associated with reduced mortality from myocardial infarction. Neither dietary seafood nor n-3 fatty acid intake was associated with a reduced risk of death from stroke or ischemic heart disease other than acute myocardial infarction. However, approximately a 20% reduction in total mortality associated with weekly fish/shellfish intake was observed in the study population (relative risk = 0.79, 95% confidence interval: 0.69, 0.91). These prospective data suggest that eating fish and shellfish weekly reduces the risk of fatal myocardial infarction in middle-aged and older men in Shanghai, China.     

Who is sensitive to the effects of particulate air pollution on mortality? A case-crossover analysis of effect modifiers

BACKGROUND: Populations susceptible to the effects of particulate matter have begun to be characterized, but the independent contributions of specific factors have not been explored. METHODS: We used a case-crossover study to examine PM10-associated mortality risk during 1988-1991 among 65,180 elderly residents of Cook County, Illinois, who had a history of hospitalization for heart or lung disease. We assessed how the effect was independently modified by specific diagnoses and personal characteristics. RESULTS: We found a 1.14% (95% confidence interval [CI] = 0.44% to 1.85%) increased risk of death per 10 microg/m3 increase in ambient PM10 concentration. Persons with heart or lung disease-but no specific diagnosis of myocardial infarction, diabetes, congestive heart failure, chronic obstructive pulmonary disorder, or conduction disorders-were at 0.74% (-0.29% to 1.79%) increased risk. Persons with a history of myocardial infarction had a 2.7-fold higher risk (CI = -2.1 to 7.4). Those with diabetes carried a 2.0-fold higher risk (CI = -1.5 to 5.5). Risk appeared to decrease with age among elderly men and increase with age among elderly women, but the estimated 3-way interaction was not precise enough to exclude the null. We found no indication that susceptibility varied by group-level socioeconomic measures. CONCLUSION: Among a frail population, individuals diagnosed with myocardial infarction or diabetes were at greatest risk of death associated with high concentrations of PM10. These results suggest that their susceptibility may derive from prior vascular damage to the heart.     

Traditional and novel risk factors for clinically diagnosed abdominal aortic aneurysm: the Kaiser multiphasic health checkup cohort study

BACKGROUND: Identification of risk factors for and early diagnosis of clinically significant abdominal aortic aneurysm (AAA) before rupture is vital to optimize outcomes in these patients. Our aim was to examine traditional and three novel potential risk factors (abdominal obesity, white blood cell count, and kidney function) for abdominal aortic aneurysm (AAA, comprising discharge diagnosis or surgical repair) in a large multiethnic population. METHODS: Cohort study (N =104,813) conducted at an integrated health care delivery system in northern California. RESULTS: After a median of 13 years, 605 AAA events (490 in men and 115 in women; 91 [15%] fatal) were observed. In multivariable analysis, factors significantly associated with risk of clinically detected AAA included male gender, older age, black race (inversely), low educational attainment, cigarette smoking (with dose-response relation), height, treated and untreated hypertension, high total serum cholesterol, elevated white blood cell count, known coronary artery disease, history of intermittent claudication, and reduced kidney function. A significant Asian race by gender interaction was found such that Asian race had a (borderline significant) protective association with AAA in men but not in women. CONCLUSIONS: Our findings confirm that major atherosclerotic risk factors, except for diabetes and obesity, are also prospectively related to AAA and suggest that elevated white blood cell count and reduced kidney function may improve risk stratification for clinically relevant AAA.