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Biomedical subjects

Kiang Liu

Publications and source records attributed to Kiang Liu.

At least 73 records · Page 4Linked to original sources
PubMed2004

Alteration in fluid mechanics in porcine femoral arteries with atheroma development.

Although the relationship between the local wall shear stresses (WSS) and atheroma development has been previously studied, the effect of variable regional wall distensibility with early atherosclerotic lesions and its effect on local hemodynamics have not been well investigated. We induced early atherosclerotic lesion development in one femoral artery in a Yucatan miniswine model with the contralateral artery serving as control. Eight weeks following atheroma formation, hemodynamic and intravascular ultrasound image data were obtained. Using the measured regional arterial distension as the moving boundary condition, unsteady laminar incompressible computational analysis was performed on the reconstructed arterial segments. With the development of early atherosclerotic lesions, there was increased wall distensibility and an increase in the computed normalized wall shear stress amplitude (NWSA). Alterations in the local fluid mechanics and mass transport at these sites may need to be considered in our understanding of the continued growth of these lesions.

Aging↗
PubMed2004

BMI and health-related quality of life in adults 65 years and older.

OBJECTIVE: To examine relationships of BMI with health-related quality of life in adults 65 years and older. RESEARCH METHODS AND PROCEDURES: In 1996, a health survey was mailed to all surviving participants > or = 65 years old from the Chicago Heart Association Detection Project in Industry Study (1967 to 1973). The response rate was 60%, and the sample included 3981 male and 3099 female respondents. BMI (kilograms per meter squared) was classified into four groups: underweight (<18.5), normal weight (18.5 to 24.9), overweight (25.0 to 29.9), and obese (> or = 30.0). Main outcome measures were Health Status Questionnaire-12 scores (ranging from 0 to 100) assessing eight domains: health perception, physical functioning, role limitations-physical, bodily pain, energy/fatigue, social functioning, role limitations-mental, and mental health. The higher the score, the better the outcome. RESULTS: With adjustment for age, race, education, smoking, and alcohol intake, obesity was associated with lower health perception and poorer physical and social functioning (women only) but not impaired mental health. Overweight was associated with impaired physical well-being among women only. Both underweight men and women reported impairment in physical, social, and mental well-being. For example, multivariable-adjusted health perception domain scores for women were 50.8 (underweight), 62.7 (normal weight), 60.5 (overweight), and 52.1 (obese), respectively. Associations weakened but remained significant with further adjustment for comorbidities. DISCUSSION: Compared with normal-weight people, both underweight and obese older adults reported impaired quality of life, particularly worse physical functioning and physical well-being. These results reinforce the importance of normal body weight in older age.

Aged↗
PubMed2004

Peripheral arterial disease in African Americans: clinical characteristics, leg symptoms, and lower extremity functioning.

OBJECTIVES: The describe peripheral arterial disease (PAD) in African Americans, and compare findings in African Americans and whites with PAD. DESIGN: Cross-sectional. SETTING: Three academic medical centers. PARTICIPANTS: Three hundred sixty-six whites and 76 African Americans with PAD (as defined by an ankle brachial index (ABI) <0.90) aged 55 and older identified from lower extremity arterial studies performed between 1996 and the fall of 1999. MEASUREMENTS: Comprehensive medical interview, body mass index, and neuropathy score. Functional measurements included the 6-minute walk distance, 4-m walking velocity, and the summary performance score. RESULTS: Age- and sex-adjusted results showed that African Americans had a lower mean ABI than whites (0.60 vs 0.66, P=.001), were less likely to be college graduates (13.7% vs 44.4%, P<.001), and had nearly twice the prevalence of diabetes mellitus (46.8% vs 28.0%, P=.001). After adjusting for age, sex, education level, and ABI, African Americans had a higher prevalence of no exertional leg pain (28.0% vs 18.2%, P=.044) and leg pain with exertion and rest (30.0% vs 17.3%, P=.023). African Americans had a shorter 6-minute walk distance (989 vs 1,156 ft, P<.001), a slower normal-pace 4-m walking velocity (0.79 vs 0.89 m/s, P<.001), a slower fast-pace 4-m walking velocity (1.12 vs 1.20 m/s, P=.012), and a lower summary performance score (8.8 vs 9.6, P=.018) than whites. These differences in functioning were attenuated after adjusting for age, sex, ABI, education, and leg symptoms. CONCLUSION: Poorer lower extremity functioning in African Americans was largely explained by differences in leg symptoms and, to a somewhat lesser degree, lower ABI levels and poorer education in African Americans than in whites. Further study is needed to determine whether these findings affect racial treatment disparities and poorer outcomes previously reported in African Americans than in whites with PAD.

Black or African American↗
PubMed2004

Inflammatory and thrombotic blood markers and walking-related disability in men and women with and without peripheral arterial disease.

OBJECTIVES: To determine whether higher circulating levels of thrombotic and inflammatory markers are associated with greater disability. DESIGN: Cross-sectional. SETTING: Academic medical center. PARTICIPANTS: A total of 346 men and women with peripheral arterial disease (PAD) and 203 without PAD. MEASUREMENTS: Disability measures were the Walking Impairment Questionnaire (WIQ) distance, speed, and stair-climbing scores and the 36-item Short-Form (SF-36) physical functioning score. The SF-36 and WIQ are scored on a 0 to 100 scale (100=best). RESULTS: In persons with PAD, higher D-dimer levels were associated with lower WIQ speed scores (P<.001), lower stair-climbing scores (P<.04), and poorer SF-36 physical functioning scores (P<.01), adjusting for known and potential confounders. In participants without PAD, higher D-dimer levels were associated with lower WIQ distance scores (P<.03), lower speed scores (P<.05), and poorer SF-36 physical functioning scores (P<.02). Higher high-sensitivity C-reactive protein (hsCRP) levels were associated with lower WIQ distance (P<.02) and speed scores (P<.001) in persons without PAD. Most of these associations were attenuated after additional adjustment for objectively measured functional limitations. CONCLUSION: Higher circulating D-dimer and hsCRP levels are associated with greater disability in walking and physical functioning in individuals with and without PAD. Physiological changes that result in walking disability may mediate these associations.

Aged↗
PubMed2004

Inflammatory markers, D-dimer, pro-thrombotic factors, and physical activity levels in patients with peripheral arterial disease.

Men and women with lower extremity peripheral arterial disease (PAD) have reduced physical activity levels compared with persons without PAD. We describe associations between physical activity levels with D-dimer, pro-coagulant factors, and inflammatory markers in patients with PAD. Participants were 188 patients with PAD identified from non-invasive vascular laboratories. Physical activity was measured over 7 days with a vertical accelerometer. We measured the ankle-brachial index (ABI) and levels of D-dimer, C-reactive protein (CRP), fibrinogen, serum amyloid A (SAA), prothrombin 1.2, t-PA antigen, PAI-1, and the t-PA antigen/PAI-1 ratio. Adjusting for age, sex, race, body mass index, ABI, comorbidities, smoking, total cholesterol/HDL ratio and statin use (for CRP only), we found significant inverse linear associations between physical activity levels and log D-dimer (p = 0.002), log CRP (p < 0.001), fibrinogen (p = 0.014), and log SAA (p = 0.012). There were no significant associations between physical activity levels and other blood factors. In an analysis adjusting for all blood factors simultaneously along with known and potential confounders, log D-dimer was the only blood factor associated significantly with physical activity levels (p = 0.036). Based on these findings, future studies should assess whether interventions to increase physical activity in patients with PAD reduce levels of D-dimer and inflammatory markers.

Arterial Occlusive Diseases↗
PubMed2004

Risk factors for the metabolic syndrome: the Coronary Artery Risk Development in Young Adults (CARDIA) study, 1985-2001.

OBJECTIVE: The aim of this study was to describe the association of the metabolic syndrome with demographic characteristics and to identify modifiable risk factors for development of the metabolic syndrome. RESEARCH DESIGN AND METHODS: Men and women (55%) aged 18-30 years from the Coronary Artery Risk Development in Young Adults (CARDIA) study without the metabolic syndrome at baseline (n = 4,192, 49% black) were followed-up from 1985 to 2001. Incident metabolic syndrome, defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria, was ascertained 7, 10, and 15 years after baseline. Risk factors were measured via clinical examination and standardized questionnaires. RESULTS: The age-adjusted rate of metabolic syndrome was 10 per 1,000 person-years (n = 575). Metabolic syndrome risk increased with age and was higher among black participants and those with less than a high school education. Higher baseline BMI, no alcohol intake (versus one to three drinks per day), higher intake of dietary carbohydrates, and lower intake of crude fiber were each associated with an increased risk for the metabolic syndrome (relative risk [RR] ranging from 1.3 to 1.9), and physical activity was protective (RR 0.84 [95% CI 0.76-0.92]). In models adjusting simultaneously for all factors, black participants and women were less likely to develop metabolic syndrome. Risk for metabolic syndrome increased 23% (20-27%) per 4.5 kg (10 lb) of weight gained, whereas regular physical activity over time versus low activity was protective (RR 0.49 [0.34-0.70]). CONCLUSIONS: BMI and weight gain are important risk factors for the metabolic syndrome. Regular physical activity may counter this risk.

Adult↗
PubMed2004

Longitudinal associations of age, anthropometric and lifestyle factors with serum total insulin-like growth factor-I and IGF binding protein-3 levels in Black and White men: the CARDIA Male Hormone Study.

Although several studies have assessed cross-sectional correlates of serum insulin-like growth factor-I (IGF-I) and IGF binding protein-3 (IGFBP-3), there are no longitudinal studies of the correlates of long-term changes in these measures. We examined the 8-year longitudinal associations of age, body mass index (BMI), waist circumference, physical activity, number of cigarettes smoked per day, and alcohol intake with serum total IGF-I and IGFBP-3 concentrations in 622 Black and 796 White male participants of the Coronary Artery Risk Development in Young Adults Study who were ages 20 to 34 years at the time of the first IGF measurement. In generalized estimating equation analyses, IGF-I decreased by 5.6 and 5.9 ng/mL per year increase in age for Black and White men, respectively (P< 0.0001), and there was an age-related decline in IGFBP-3 that was stronger in Whites (P < 0.0001) than Blacks (P = 0.21). Average IGF-I (beta = -17.51 ng/mL) and IGFBP-3 (beta = -355.4 ng/mL) levels across all three exams were lower in Blacks than Whites (P < 0.0001). Increased BMI was associated with decreased IGF-I (P < 0.0002), but was not associated with IGFBP-3. There were no meaningful associations with waist circumference. Increased physical activity was associated with a decrease in IGFBP-3 (P < 0.05), but was not associated with IGF-I. In White men, there were weak inverse associations between the number of cigarettes smoked per day with IGF-I (P=0.15) and with IGFBP-3 (P = 0.19), and in Black men, increased alcohol intake was associated with a decrease in IGF-I (P = 0.011). In conclusion, these results support an age-related decline and Black-White difference in serum IGF-I and IGFBP-3 levels. Importantly, they suggest that IGF-I and/or IGFBP-3 levels could be influenced by changes in BMI, and perhaps by physical activity, alcohol intake, and cigarette smoking.

Adult↗
PubMed2003

Cardiorespiratory fitness in young adulthood and the development of cardiovascular disease risk factors.

CONTEXT: Low cardiorespiratory fitness is an established risk factor for cardiovascular and total mortality; however, mechanisms responsible for these associations are uncertain. OBJECTIVE: To test whether low fitness, estimated by short duration on a maximal treadmill test, predicted the development of cardiovascular disease risk factors and whether improving fitness (increase in treadmill test duration between examinations) was associated with risk reduction. DESIGN, SETTING, AND PARTICIPANTS: Population-based longitudinal cohort study of men and women 18 to 30 years of age in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Participants who completed the treadmill examination according to the Balke protocol at baseline were followed up from 1985-1986 to 2000-2001. A subset of participants (n = 2478) repeated the exercise test in 1992-1993. MAIN OUTCOME MEASURES: Incident type 2 diabetes, hypertension, the metabolic syndrome (defined according to National Cholesterol Education Program Adult Treatment Panel III), and hypercholesterolemia (low-density lipoprotein cholesterol > or =160 mg/dL [4.14 mmol/L]). RESULTS: During the 15-year study period, the rates of incident diabetes, hypertension, the metabolic syndrome, and hypercholesterolemia were 2.8, 13.0, 10.2, and 11.7 per 1000 person-years, respectively. After adjustment for age, race, sex, smoking, and family history of diabetes, hypertension, or premature myocardial infarction, participants with low fitness (<20th percentile) were 3- to 6-fold more likely to develop diabetes, hypertension, and the metabolic syndrome than participants with high fitness (> or =60th percentile), all P<.001. Adjusting for baseline body mass index diminished the strength of these associations to 2-fold (all P<.001). In contrast, the association between low fitness and hypercholesterolemia was modest (hazard ratio [HR], 1.4; 95% confidence interval [CI], 1.1-1.7; P =.02) and attenuated to marginal significance after body mass index adjustment (P =.13). Improved fitness over 7 years was associated with a reduced risk of developing diabetes (HR, 0.4; 95% CI, 0.2-1.0; P =.04) and the metabolic syndrome (HR, 0.5; 95% CI, 0.3-0.7; P<.001), but the strength and significance of these associations was reduced after accounting for changes in weight. CONCLUSIONS: Poor fitness in young adults is associated with the development of cardiovascular disease risk factors. These associations involve obesity and may be modified by improving fitness.

Adult↗
PubMed2003

Body mass index in middle age and health-related quality of life in older age: the Chicago heart association detection project in industry study.

BACKGROUND: Overweight and obesity are associated with higher morbidity and shorter life expectancy, but the effect of body mass index (BMI) (calculated as weight in kilograms divided by the square of height in meters) ascertained during middle age on subsequent quality of life among older survivors is unknown. This study evaluates whether BMI in middle age is related to health-related quality of life in older age. METHODS: This prospective cohort of adults from the Chicago Heart Association Detection Project in Industry included 6766 middle-aged men and women, aged 36 to 64 years, without diabetes mellitus or myocardial infarction at baseline (November 7, 1967-January 8, 1973), who completed a 26-year follow-up questionnaire in 1996 when they were 65 years and older. Relationships of baseline BMI (categories: normal weight, overweight, and obese) to mean 26-year follow-up Health Status Questionnaire 12 scores (measuring physical, mental, and social well-being) were assessed. RESULTS: For men and women, BMI had significant inverse-graded associations with all Health Status Questionnaire 12 scores (P<.01 for trend for all). Scores (adjusted for baseline cardiovascular disease risk factors and 1996 age) were highest (best) in normal-weight individuals (BMI, 18.5-<25.0) and decreased significantly (P range,.006-<.001 for trend) with higher BMI, with worst outcomes for obese persons (BMI, >or=30.0). A higher multivariate-adjusted percentage of normal-weight persons reported excellent or very good health compared with overweight and obese persons: for women, 46.8% vs 37.9% and 24.3%; and for men, 53.8% vs 49.1% and 36.5% (P<.001 for trend). CONCLUSIONS: A higher BMI in middle age is associated with a poorer quality of life in older age. Preventive measures may lessen the burden of disease and impaired quality of life associated with excess weight.

Aged↗
PubMed2003

Favorable cardiovascular risk profile in middle age and health-related quality of life in older age.

BACKGROUND: Life expectancy is greater for people with favorable midlife cardiovascular risk profiles (ie, low risk). However, some speculate that increased longevity may lead to large numbers of ill, disabled, older persons with lower quality of life. Few data exist on this important issue. This study evaluates the relationship of midlife low-risk status to quality of life and illness in older age. METHODS: Cohort of middle-aged adults from the Chicago Heart Association Detection Project in Industry (2692 women and 3650 men; baseline ages, 36-64 years [average age, 73.2 years in 1996]) without baseline (1967-1973) major electrocardiographic abnormalities or history of diabetes or myocardial infarction. Quality of life (12-item Health Status Questionnaire [HSQ-12] on physical, mental, and social well-being) and self-reported diseases were assessed after 26 years of follow-up. Baseline risk strata included low risk (favorable blood pressure and serum cholesterol levels, no smoking, and no minor electrocardiographic abnormalities); 0 risk factors (ie, no high risk factors but >or=1 risk factors not at favorable levels); or any 1, any 2, or 3 or more of the following 4 risk factors: high blood pressure, high serum cholesterol level, smoking, and minor electrocardiographic abnormalities. The HSQ-12 scores and disease outcomes for low risk were compared with other strata. RESULTS: Adjusted scores for physical, mental, social functioning, and disease-free outcomes were highest for low-risk individuals and decreased significantly with number of risk factors (eg, 58% of low-risk women had excellent/very good health compared with 28% of women with >or=3 risk factors). CONCLUSIONS: Favorable cardiovascular risk profile in middle age is associated with better quality of life and lower risk of diseases in older age. Moreover, the fewer the risk factors, the higher the quality of life.

Adult↗
PubMed2003

The effects of a low-fat/high-fiber diet on sex hormone levels and menstrual cycling in premenopausal women: a 12-month randomized trial (the diet and hormone study).

BACKGROUND: Reduction of cumulative exposure to endogenous ovarian steroid hormones is a postulated method for reducing the risk of carcinoma of the breast and other malignancies. Although there are data from trials evaluating the effect of low-fat and high-fiber diets on sex hormone levels in premenopausal women, to the authors' knowledge none of these trials has combined a relatively large number of participants, follow-up of > 2-3 months, parallel controls receiving a usual diet, and careful timing of blood sampling within the menstrual cycle. METHODS: A total of 213 healthy women, ages 20-40 years, were randomly assigned to follow their usual diet or to adopt an isocaloric diet with goals of 20% calories as fat, total fiber of 25 g/day, and at least 8 fruit or vegetable servings per day. Serum levels of total estradiol (E2), sex hormone-binding globulin (SHBG), non-SHBG-bound estradiol (NSBE2), SHBG, and progesterone were evaluated during a menstrual cycle at baseline, and at 4 cycles (C4) and 12 cycles (C12) after the start of the intervention. Serum was collected during each test cycle 7-9 days after the detection of an luteinizing hormone peak in the urine. One hundred eighty-nine women provided serum at C4 and 176 women at C12. RESULTS: Serum E2 decreased by an average of 7.5% or 7.8 pg/mL (95% confidence interval [95% CI], -16.0-0.04) at C12 in the intervention group, versus a decrease of 0.9% or 0.9 pg/mL (95% CI, -9.5-7.7) in the control group (the P value for the difference between the treatment groups was 0.25). Results for NSBE2 were very similar to those for total estradiol. There were no material effects found to result from intervention with regard to SHBG or progesterone. The results did not differ by baseline age, body mass index, or baseline hormone level above or below the median, and were not likely to be affected by weight change, which amounted to a mean loss of only 0.23 kg in the diet group versus a gain of 0.17 kg in the control group. The decrease in serum E2 associated with intervention was not greater when subjects were stratified by self-reported adherence to the dietary goals. CONCLUSIONS: The results of the current study suggest that the effects of this isocaloric low-fat, high-fiber diet pattern on circulating ovarian steroids were modest or nonexistent. However, the observed 7.5% reduction in estradiol could have biologic significance if it persisted over many years. Moreover, underestimation of the true dietary effect could have occurred because of incomplete adherence to assigned diets. Weight loss and weight control through midlife could be a more effective and feasible approach to dietary intervention in reducing the risk of breast carcinoma.

Adult↗
PubMed2003

Psychosocial factors and risk of hypertension: the Coronary Artery Risk Development in Young Adults (CARDIA) study.

CONTEXT: Although psychosocial factors are correlated, previous studies on risk factors for hypertension have typically examined psychosocial factors individually and have yielded inconsistent findings. OBJECTIVE: To examine the role of psychosocial factors of time urgency/impatience (TUI), achievement striving/competitiveness (ASC), hostility, depression, and anxiety on long-term risk of hypertension. DESIGN, SETTING, AND STUDY POPULATION: A population-based, prospective, observational study using participant data from the Coronary Artery Risk Development in Young Adults (CARDIA) study. A total of 3308 black and white adults aged 18 to 30 years (when recruited in 1985 and 1986) from 4 US metropolitan areas and followed up through 2000 to 2001. MAIN OUTCOME MEASURES: Fifteen-year cumulative incidence of hypertension (systolic blood pressure of 140 mm Hg or higher, diastolic blood pressure of 90 mm Hg or higher, or taking antihypertensive medication). RESULTS: The incidence of hypertension at year 15 was 15% from baseline and 13.6% from year 5. After adjusting for the same set of hypertension risk factors and each of the psychosocial factors of TUI, ASC, hostility, depression, and anxiety in 5 separate logistic regression models, higher TUI and hostility were significantly associated with risk of developing hypertension at 15-year follow-up for the total sample. Compared with the lowest score group, the adjusted odds ratio (OR) for TUI was 1.51 (95% confidence interval [CI], 1.12-2.03) for a score of 1; 1.47 (95% CI, 1.08-2.02) for a score of 2; and 1.84 (95% CI, 1.29-2.62) for a score of 3 to 4 (P for trend =.001). Compared with the lowest quartile group, the adjusted OR for hostility was 1.06 (95% CI, 0.76-1.47) for quartile 2; 1.38 (95% CI, 1.00-1.91) for quartile 3; and 1.84 (95% CI, 1.33-2.54) for quartile 4 (P for trend <.001). No consistent patterns were found for ASC, depression, or anxiety. Race- and sex-specific analyses and multivariable models with simultaneous adjustment for all 5 psychosocial factors and other hypertension risk factors had generally similar results. CONCLUSION: Among young adults, TUI and hostility were associated with a dose-response increase in the long-term risk of hypertension.

Adult↗
PubMed2003

Relation of levels of hemostatic factors and inflammatory markers to the ankle brachial index.

Associations between hemostatic and inflammatory markers relative to the ankle brachial index (ABI), an indicator of the presence and severity of peripheral arterial disease (PAD), are not fully understood. We studied relations among selected hemostatic factors, inflammatory markers, and the ankle brachial index (ABI) in patients with and without peripheral arterial disease (PAD). Participants were 370 men and women with ABI <0.90 and 231 patients with ABI 0.90 to 1.50 identified from noninvasive vascular laboratories and general medicine practice. Blood factors were D-dimer, prothrombin 1.2, tissue plasminogen activator (t-PA) antigen, plasminogen activator inhibitor-1 (PAI-1), and inflammatory markers (high-sensitivity C-reactive protein [CRP], fibrinogen, and serum amyloid A [SAA]). Among patients without a history of cardiac or cerebrovascular disease, the ABI was significantly inversely associated with log D-dimer (p <0.001), log prothrombin 1.2 (p = 0.001), log CRP (p <0.001), and log fibrinogen (p = 0.005) in unadjusted analyses. In multivariable regression analyses adjusting for all blood factors as well as potential confounders, D-dimer was associated independently with ABI in participants with a history of cardiac or cerebrovascular disease (p = 0.003) and in participants without a history of cardiac or cerebrovascular disease (p = 0.017). In these analyses, CRP was associated independently with ABI among participants with a history of cardiac or cerebrovascular disease (p = 0.026). CRP was not associated independently with ABI in participants without a history of cardiac or cerebrovascular disease. We conclude that D-dimer levels may be more sensitive than other blood markers for measuring the extent of atherosclerosis in lower extremity arteries.

Aged↗
PubMed2003

D-dimer, inflammatory markers, and lower extremity functioning in patients with and without peripheral arterial disease.

BACKGROUND: We determined whether higher levels of D-dimer, C-reactive protein (CRP), fibrinogen, and serum amyloid A are associated independently with functional impairment in patients with and without peripheral arterial disease (PAD). METHODS AND RESULTS: Participants were 370 men and women with PAD (ankle brachial index <0.90) and 231 without PAD. Functional outcomes were 6-minute walk distance and 4-meter walking velocity. A summary performance score combined performance in walking speed, standing balance, and time for 5 repeated chair rises into an ordinal score ranging from 0 to 12 (12=best). Adjusting for age, sex, ankle brachial index, comorbidities, and other potential mediators and confounders, D-dimer levels were associated independently and inversely with performance on all 3 functional measures in the entire cohort and among patients with and without PAD, respectively. Adjusting for known and potential confounders, CRP levels were associated independently with 6-minute walk distance and the summary performance score among participants with PAD. No significant associations were observed between CRP and the functional measures among participants without PAD. Fibrinogen and SAA levels were not associated independently with the functional measures. CONCLUSIONS: Higher D-dimer levels are associated with poorer functioning among individuals with and without PAD. Higher CRP levels were associated with poorer 6-minute walk performance and a lower summary performance score among participants with PAD but not among those without PAD. Additional study is needed to determine whether D-dimer and CRP are involved in the pathophysiology of functional impairment or whether they are simply sensitive markers of the extent of systemic atherosclerosis.

Aged↗
PubMed2003

Middle age cardiovascular risk factors and abdominal aortic aneurysm in older age.

Few prospective studies have examined associations between major cardiovascular risk factors and occurrence of abdominal aortic aneurysm; findings from cross-sectional studies are inconsistent. This long-term population-based study assessed relationships of major risk factors in middle-age to clinical nonfatal plus fatal abdominal aortic aneurysm in older-age in the Chicago Heart Association Detection Project in Industry cohort--10 574 men and 8700 women baseline ages 40 to 64 years screened for risk factors in 1967-1973 at workplaces. With average follow-up of 30 years and clinical cases identified from Medicare records and death certificates, risk factor relationships to abdominal aortic aneurysm occurrence were assessed by Cox regression. There were among men 309 cases and among women, 109--most from Medicare records. Most findings were qualitatively similar for men and women. In multivariate analyses (5 models), hazard ratios for abdominal aortic aneurysm were significantly greater for men than women (> or =1.97), with older age (> or =1.63/5 years), higher serum cholesterol (> or =1.30/40.0 mg/dL), cigarettes/d (> or =2.43/20 cigarettes), past smoking (> or =1.41), height (> or =1.17/7 cm), evidence of adverse blood pressure (hazard ratio 1.10/20 mm Hg higher systolic pressure, 1.12 to 1.14/12 mm Hg higher diastolic pressure, 1.87 with history of treated hypertension). It is concluded that major cardiovascular risk factors--serum cholesterol, smoking, and blood pressure--in middle age relate significantly to risk of abdominal aortic aneurysm in persons surviving into older age.

Adult↗
PubMed2003

Electron-beam tomography coronary artery calcium and cardiac events: a 37-month follow-up of 5635 initially asymptomatic low- to intermediate-risk adults.

BACKGROUND: Conventional coronary artery disease (CAD) risk factors fail to explain nearly 50% of CAD events. This study examines the association between electron-beam tomography (EBT) coronary artery calcium (CAC) and cardiac events in initially asymptomatic low- to intermediate-risk individuals, with adjustment for the presence of hypercholesterolemia, hypertension, diabetes, and a history of cigarette smoking. METHODS AND RESULTS: The study was performed in 8855 initially asymptomatic adults 30 to 76 years old (26% women) who self-referred for EBT CAC screening. Conventional CAD risk factors were elicited by use of a questionnaire. After 37+/-12 months, information on the occurrence of cardiac events was collected and confirmed by use of medical records and death certificates. In men, events (n=192) were associated with the presence of CAC (RR=10.5, P<0.001), diabetes (RR=1.98, P=0.008), and smoking (RR=1.4, P=0.025), whereas in women, events (n=32) were linked to the presence of CAC (RR=2.6, P=0.037) and not risk factors. The presence of CAC provided incremental prognostic information in addition to age and other risk factors. CONCLUSIONS: The association between EBT CAC and cardiac events observed in this study of initially asymptomatic, middle-aged, low to intermediate-risk individuals presenting for screening suggests that in this group, knowledge of the presence of EBT CAC provides incremental information in addition to that defined by conventional CAD risk assessment.

Adult↗
PubMed2003

Impact of minor electrocardiographic ST-segment and/or T-wave abnormalities on cardiovascular mortality during long-term follow-up.

Minor ST-T abnormalities are common on the resting electrocardiogram of otherwise healthy persons, but the long-term importance of these findings has not been extensively evaluated, especially in women. In a prospective study, 7,985 women and 9,630 men (aged 40 to 64 years at baseline) without other electrocardiographic abnormalities and free of previous coronary heart disease (CHD) were studied using Cox regression for 22-years of follow-up. Primary outcomes were death from CHD and total cardiovascular disease (CVD); total mortality was a secondary outcome. Minnesota Code was employed to assess the presence or absence of electrocardiographic abnormalities. Analyses compared persons with minor Minnesota Code ST-segment (codes 4-3 or 4-4) or T-wave findings (codes 5-3 or 5-4) to those with normal electrocardiographic findings. In combined analyses of men and women adjusted for age, isolated minor T-wave abnormality, minor ST-segment depression, or a combination of minor ST-segment and T-wave abnormalities were each associated with increased mortality risks. For CHD mortality, hazard ratios (HRs) ranged from 1.60 to 2.10; for CVD mortality, HRs ranged from 1.50 to 1.95; and for total mortality, HRs ranged from 1.31 to 1.50 (p <0.05 for all HRs). In separate analyses by gender adjusted for age, increased risks were observed for combined ST-T-wave abnormalities in both genders for CHD and CVD mortality (HR 1.72 to 1.75 for men, p <0.05; HR 2.07 to 2.51 for women, p <0.001). These data indicate that nonspecific (minor) ST-segment depression and/or T-wave abnormalities have a long-term prognostic impact for CHD and CVD death in middle-aged women and men and can be considered markers of heightened CHD and CVD risk.

Adult↗