Effect of 6-month high-impact step aerobics and resistance training on BMD and tibial bending strength in sedentary premenopausal women.

The rationale of this study was to examine the effectiveness of 6-month high-impact step aerobics (SA) or moderate-intensity resistance training exercise (RT) on bone mineral density (BMD) and bone bending strength in sedentary women. Results show that SA enhanced BMD in the heel, lower leg, and lumbar spine 2. INTRODUCTION: To determine the effectiveness of 6 months of high-impact step aerobics (SA) or moderate-intensity resistance training (RT) on areal bone mineral density (aBMD) and tibial bending strength in sedentary premenopausal women. METHODS: Sixty-nine women (20-35 years old) who were randomly assigned to RT (n = 22), SA (n = 26), or non-treatment control (CON, n = 21) groups completed the study. SA had a minimum of 50 high-impact landings each training session. RT had a periodized lower body resistance training program incorporating eight exercises (65-85% of 1 repetition maximum: 1-RM). Both RT and SA met 3 times weekly. aBMD was assessed using dual X-ray absorptiometry (DXA). Tibial bending strength was assessed using mechanical response tissue analysis (MRTA). Measurements at 6 months were compared to baseline using ANCOVA, adjusted for baseline measures and covariates with α = 0.05. RESULTS: Calcaneus aBMD (0.0176 vs -0.0019 or -0.0009 g/cm2 relative to RT, p < 0.004, and CON, p < 0.006, respectively), lower leg aBMD (0.0105 vs -0.0036 g/cm2, relative to RT, p = 0.02), and lumbar spine 2 (L2) aBMD (0.0082 vs -0.0157 g/cm2 relative to CON, p < 0.02) were significantly greater in the SA group after 6 months. Tibial bending strength and bone resorption biomarkers were unchanged in all three groups after 6 months. CONCLUSION: Sedentary premenopausal women engaging in 6 months of high-impact aerobic exercise improved aBMD in the calcaneus, lower leg, and L2.

The metabolic syndrome and diabetes mellitus as predictors of thoracic aortic calcification as detected by non-contrast computed tomography in the Multi-Ethnic Study of Atherosclerosis.

AIMS: The metabolic syndrome (MetS) is a clustering of low levels of HDL cholesterol, hyperglycaemia, high waist circumference, hypertension and elevated triglycerides, and is associated with cardiovascular disease. Calcified atherosclerotic plaque in the thoracic aorta (TAC), measured by non-contrast cardiac computed tomography (CT) scans, is a marker for atherosclerosis and relates to mortality. We sought to evaluate the independent association of MetS and TAC on cardiac CT scans. METHODS: We examined the relation of the MetS, and each of its components, to the prevalence of TAC, measured from 2000 to 2002 in 6778 white, Chinese, African-American and Hispanic participants in the Multi-Ethnic Study of Atherosclerosis (MESA). RESULTS: Adjusting for age, gender, race, smoking, LDL cholesterol and lipid-lowering medications, relative risks and 95% confidence intervals (CI) for a TAC score > 0 were: 1.19 (95% CI 1.11 to 1.28) for participants with MetS, 1.34 (95% CI 1.21 to 1.49) for those with diabetes and MetS, and 1.33 (95% CI 1.11, 1.58) for those with diabetes and no MetS compared with participants who were free of the MetS and diabetes. Associations were found for most of the components of the MetS with TAC. CONCLUSIONS: We conclude that in adults without known heart disease, the MetS, most of its components and diabetes are associated with a higher prevalence of calcified atherosclerotic plaque in the thoracic arteries in a multi-ethnic population of men and women.

Abdominal aortic diameter and vascular atherosclerosis: the Multi-Ethnic Study of Atherosclerosis.

OBJECTIVES: To gain insight into early mechanisms of aortic widening, we examined associations between the diameter of the abdominal aorta (AD) and cardiovascular disease (CVD) risk factors and biomarkers, as well as measures of subclinical atherosclerosis, in a multi-ethnic population. DESIGN: Cross-sectional cohort. METHODS: A total of 1926 participants (mean age 62, 50% women) underwent chest and abdomen scanning by computed tomography, ultrasound of the carotid arteries, and CVD risk factor assessment. AD was measured 5 cm above and at the bifurcation. RESULTS: In a model containing traditional CVD risk factors, biomarkers and ethnicity, only age (standardized ß = 0.97), male sex (ß = 1.88), body surface area (standardized ß = 0.92), current smoking (ß = 0.42), D-dimer levels (ß = 0.19) and hypertension (ß = 0.53) were independently and significantly associated with increasing AD (in mm) at the bifurcation; use of cholesterol-lowering medications predicted smaller AD (ß = -0.70) (P < 0.01 for all). These findings were similar for AD 5 cm above the bifurcation with one exception: compared to Caucasian-Americans, Americans of Chinese, African and Hispanic descent had significantly smaller AD 5 cm above the bifurcation (ß's = -0.59, -0.49, and -0.52, respectively, all P < 0.01), whereas AD at the bifurcation did not differ by ethnicity. Physical activity, alcohol consumption, diabetes and levels of IL-6, CRP and homocysteine were not independently associated with AD. Higher aortic and coronary artery calcium burden, but not common carotid artery intima-media thickness, were independently, but modestly (ß = 0.11 to 0.19), associated with larger AD. CONCLUSIONS: Incremental widening of the aortic diameter shared some, but not all, risk factors for occlusive vascular disease.

Effect of high-impact aerobics and strength training on BMD in young women aged 20-35 years.

To evaluate the effects of a 12-month exercise intervention using either high-impact step aerobic exercise or moderate-intensity strength training on areal bone mineral density (aBMD) we studied 51 untrained women, aged 20-35 years, for this study. Whole body and heel and wrist aBMD were measured by dual-energy X-ray absorptiometry (DXA, Hologic or PIXI Lunar). Subjects were randomly assigned to: impact-loaded step aerobic exercise (SA, n=15), moderate-intensity lower body strength training (ST, n=16) or non-exercise control (CON, n=20). Data analysis only included those who completed 95% of each training routine and attended at least 80% of all sessions. Group differences in aBMD, leg press strength and urinary cross-link deoxypridinoline (µDPD) were analysed using analysis of variance. After a 12-month intervention, the SA elicited an increase in aBMD of the heel (4.4%, p<0.05) and leg press strength (15%, p<0.05), relative to baseline. Meanwhile, the ST showed an increase in leg press strength (48%, p<0.05) with no significant increase in aBMD at any measured site. Similar and unchanged µDPD was observed in all 3 groups at baseline, 6 and 12 months. In conclusion, a 12-month high-impact step aerobic exercise resulted in a significant increase in the heel aBMD in untrained young women, who complied with the exercise regimen. A moderate intensity strength training intervention of similar duration had no effect on aBMD although leg strength increased significantly.

Forced vital capacity paired with Framingham Risk Score for prediction of all-cause mortality.

Forced vital capacity (FVC) measures lung function and predicts coronary heart disease (CHD); whether it provides additive prediction over CHD risk factors has not been established. We examined whether FVC adds to the prediction of all-cause mortality provided by Framingham Risk Score (FRS) alone. We examined 5,485 (61.1 million projected) nonsmoking adults from the USA who were aged 20-79 yrs. Subjects were from the Third National Health and Nutrition Examination Survey, were without obstructive lung disease, had FVC measurements and had ≤ 12 yrs (mean 8.8 yrs) mortality follow-up. We performed Cox regression analysis to examine whether FVC and forced expiratory volume in 1 s (FEV(1)) (categorised as low ≤ 85% predicted, borderline 86-94% predicted and normal ≥ 95% predicted) within FRS groups (10-yr risk of cardiovascular disease low <10%, intermediate 10-20%, high 20%) predict mortality. Receiver operator characteristic analysis examined whether FVC and FEV(1) added to the prediction provided by FRS. Low-, intermediate- and high-risk FRS groups had 79.5% (n = 4,361), 10.1% (n = 555) and 10.4% (n = 569) persons, respectively. Only the intermediate FRS group showed a graded increase in mortality (10.7, 18.2 and 42.8% per 1,000 person-yrs from highest to lowest FVC categories, respectively); those with low FVC had an almost three-fold greater risk of mortality (hazard ratio 2.64; p<0.01) than those with normal FVC. FVC provided incremental additive value for predicting mortality in addition to FRS for only this group (area under curve 0.65 versus 0.58; p<0.05). Similar results were obtained for FEV(1). Evaluation of lung function may be useful to improve risk stratification in persons with intermediate CHD risk where it adds to prediction of mortality over global risk assessment.

Abdominal obesity and the spectrum of global cardiometabolic risks in US adults.

OBJECTIVE: To compare the association of obesity and abdominal obesity with cardiometabolic risk factor burden and global estimated coronary heart disease (CHD) risk among multiethnic US adults. DESIGN: Cross-sectional, survey study. SUBJECTS: A total of 4456 participants (representing 194.9 million adults) aged 20-79 years in the 2003-2004 National Health and Nutrition Examination Survey (NHANES). MEASUREMENTS: Body mass index (BMI) and waist circumference (WC) measures, CHD risk factors and a 10-year estimated CHD risk based on Framingham algorithms. Obesity was defined as a BMI >or=30 kg/m(2) and abdominal obesity as a WC >88 cm in women and >102 cm in men. High CHD risk status included diabetes, cardiovascular disease (CVD) or a 10-year Framingham risk score of >20%. RESULTS: Overall, abdominal obesity was present in 42.3% of men and 62.5% of women and in 53.6% of whites, 56.9% of blacks and 50.5% of Hispanics (P<0.001 between gender and ethnicity). However, using International Diabetes Federation (IDF)-recommended WC cut points for Hispanics, the prevalence of abdominal obesity was 78.3%. Mean levels of low-density lipoprotein cholesterol (LDL-C), systolic and diastolic blood pressure, fasting glucose and C-reactive protein increased, and high-density lipoprotein cholesterol (HDL-C) decreased (P<0.001) according to BMI and WC categories, although these associations were attenuated in blacks for blood pressure, LDL-C, HDL-C and triglycerides. Of those with high WC, 25-35% had >or=3 cardiometabolic risk factors. High CHD risk among those with high WC was most common in men (27.9%) and non-Hispanic whites (23.9%). Persons with a high vs normal WC, adjusted for age, gender, ethnicity and BMI were more likely to have >or=3 cardiometabolic risk factors (odds ratio (OR)=5.1, 95% confidence interval (CI)=3.9-6.6) and were classified as high CHD risk (OR=1.5, 95% CI=1.1-2.0). CONCLUSION: The association of abdominal obesity with risk factors varies by ethnicity and is independently associated with high CHD risk status, further validating its clinical significance.

Is pulse pressure useful in predicting risk for coronary heart Disease? The Framingham heart study.

BACKGROUND: Current definitions of hypertension are based on levels of systolic blood pressure (SBP) and diastolic blood pressure (DBP), but not on pulse pressure (PP). We examined whether PP adds useful information for predicting coronary heart disease (CHD) in the population-based Framingham Heart Study. METHODS AND RESULTS: We studied 1924 men and women between 50 and 79 years of age at baseline with no clinical evidence of CHD and not taking antihypertensive drug therapy. Cox regression, adjusted for age, sex, and other risk factors, was used to assess the relations between blood pressure components and CHD risk over a 20-year follow-up. The association with CHD risk was positive for SBP, DBP, and PP, considering each pressure individually; of the 3, PP yielded the largest chi(2) statistic. When SBP and DBP were jointly entered into the multivariable model, the association with CHD risk was positive for SBP (HR, 1.22; 95% CI, 1.15 to 1.30) and negative for DBP (HR, 0. 86; 95% CI, 0.75 to 0.98). Four subgroups were defined according to SBP levels (<120, 120 to 139, 140 to 159, and >/=160 mm Hg). Within each subgroup, the association with CHD risk was negative for DBP and positive for PP. A cross-classification of SBP-DBP levels confirmed these results. CONCLUSIONS: In the middle-aged and elderly, CHD risk increased with lower DBP at any level of SBP>/=120 mm Hg, suggesting that higher PP was an important component of risk. Neither SBP nor DBP was superior to PP in predicting CHD risk.

Does the relation of blood pressure to coronary heart disease risk change with aging? The Framingham Heart Study.

BACKGROUND: We examined the relative importance of diastolic (DBP), systolic (SBP) and pulse pressure (PP) as predictors of coronary heart disease (CHD) risk in different age groups of Framingham Heart Study participants. METHODS AND RESULTS: We studied 3060 men and 3479 women between 20 and 79 years of age who were free of CHD and were not on antihypertensive drug therapy at baseline. Cox regression adjusted for age, sex, and other risk factors was used to assess the relations of BP indexes to CHD risk over a 20-year follow-up. In the group <50 years of age, DBP was the strongest predictor of CHD risk (hazard ratio [HR] per 10 mm Hg increment, 1.34; 95% CI, 1.18 to 1.51) rather than SBP (HR, 1.14; 95% CI, 1.06 to 1.24) or PP (HR, 1.02; 95% CI, 0.89 to 1.17). In the group 50 to 59 years of age, risks were comparable for all 3 BP indexes. In the older age group, the strongest predictor of CHD risk was PP (HR, 1.24; 95% CI, 1.16 to 1.33). When both SBP and DBP were considered jointly, the former was directly and the latter was inversely related to CHD risk in the oldest age group CONCLUSIONS: With increasing age, there was a gradual shift from DBP to SBP and then to PP as predictors of CHD risk. In patients <50 years of age, DBP was the strongest predictor. Age 50 to 59 years was a transition period when all 3 BP indexes were comparable predictors, and from 60 years of age on, DBP was negatively related to CHD risk so that PP became superior to SBP.

Coronary calcium does not accurately predict near-term future coronary events in high-risk adults.

BACKGROUND: Prognostic risk models have had limited success in predicting coronary events in subjects with multiple risk factors. We and others have proposed an alternative approach using radiographically detectable coronary calcium. We evaluated and compared the predictive value of these 2 approaches for determining coronary event risk in asymptomatic adults with multiple coronary risk factors. In addition, we assessed the predictive value of a risk model that included calcium score and cardiac risk-factor data. METHODS AND RESULTS: We recruited 1196 asymptomatic high-coronary-risk subjects who then underwent risk-factor assessment and cardiac electron-beam CT (EBCT) scanning and were followed up for 41 months with a 99% success rate. We applied the Framingham model and our data-derived risk model to determine the 3-year likelihood of a coronary event. The mean age of our cohort was 66 years, and mean 3-year Framingham risk was 3.3+/-3.6%. Sixty-eight percent (818 subjects) had detectable coronary calcium. There were 17 coronary deaths (1.4%) and 29 nonfatal infarctions (2. 4%). The receiver operating characteristic (ROC) curve areas calculated from the Framingham model, our data-derived risk model, and the calcium score were 0.69+/-0.05, 0.68+/-0.05, and 0.64+/-0.05, respectively (P=NS). When calcium score was included as a variable in the data-derived model, the ROC area did not change significantly (0.68+/-0.05 to 0.71+/-0.04; P=NS). CONCLUSIONS: Neither risk-factor assessment nor EBCT calcium is an accurate event predictor in high-risk asymptomatic adults. EBCT calcium score does not add significant incremental information to risk factors, and its use in clinical screening is not justified at this time.

Angiographic and intravascular ultrasound predictors of in-stent restenosis.

OBJECTIVES: This study was performed to determine predictors of in-stent restenosis from a high volume, single-center practice. BACKGROUND: Intracoronary stents have been shown to reduce the restenosis rate as compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. METHODS: Between April 1993 and March 1997, 1,706 patients with 2,343 lesions were treated with a variety of intracoronary stents. The majority of stents were placed with high pressure balloon inflations and intravascular ultrasound (IVUS) guidance. Angiographic follow-up was obtained in 1,173 patients with 1,633 lesions (70%). Clinical, angiographic and IVUS variables were prospectively recorded and analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis defined as a diameter stenosis > or =50%. RESULTS: In-stent restenosis was angiographically documented in 282 patients with 409 lesions (25%). The restenosis group had a significantly longer total stent length, smaller reference lumen diameter, smaller final minimal lumen diameter (MLD) by angiography and smaller stent lumen cross-sectional area (CSA) by IVUS. In lesions where IVUS guidance was used, the restenosis rate was 24% as compared with 29% if IVUS was not used (p < 0.05). By multivariate logistic regression analysis, longer total stent length, smaller reference lumen diameter and smaller final MLD were strong predictors of in-stent restenosis. In lesions with IVUS guidance, IVUS stent lumen CSA was a better independent predictor than the angiographic measurements. CONCLUSIONS: Achieving an optimal stent lumen CSA by using IVUS guidance during the procedure and minimizing the total stent length may reduce in-stent restenosis.

Prognostic significance of cardiac cinefluoroscopy for coronary calcific deposits in asymptomatic high risk subjects.

OBJECTIVES: This research investigated the prognostic significance of radiographically detectable coronary calcific deposits. BACKGROUND: Coronary calcific deposits are almost always associated with coronary atherosclerosis. We investigated the association between fluoroscopically determined coronary calcium and coronary heart disease end points at 1 year of follow-up. METHODS: This prospective population-based cohort study was conducted in the suburbs of Los Angeles. Fourteen hundred sixty-one asymptomatic adults with an estimated > or = 10% risk of having a coronary heart disease event within 8 years underwent cardiac cinefluoroscopy for assessment of coronary calcium at initiation of the study. Clinical status including angina, documented myocardial infarction, myocardial revascularization and death from coronary heart disease were determined after 1 year. RESULTS: The prevalence of calcific deposits was high (47%). A follow-up examination at 1 year was successfully completed in 99.9% of subjects. Six subjects (0.4%) had died from coronary heart disease and 9 (0.6%) had had a nonfatal myocardial infarction. Thirty-seven subjects (2.5%) reported angina pectoris, and 13 (0.9%) had undergone myocardial revascularization. Fifty-three subjects had at least one event during the 1-year period. Radiographically detectable calcium was associated with the presence of at least one of these end points, with a risk ratio of 2.7 (confidence limits 1.4, 4.6). The presence of coronary calcium was an independent predictor of at least one end point when controlling for age, gender and risk factors. However, three deaths due to coronary heart disease and two nonfatal myocardial infarctions occurred in subjects without detectable coronary calcium. CONCLUSIONS: The presence of coronary calcific deposits incurs an increased risk of coronary heart disease events in asymptomatic high risk subjects at 1 year. This increased risk is independent of that incurred by standard risk factors.

Insulin antibody responses after long-term intraperitoneal insulin administration via implantable programmable insulin delivery systems.

OBJECTIVE: To determine whether insulin antibodies are generated in diabetic patients after short- and long-term intraperitoneal insulin use and, if so, whether they are of potential clinical interest. Insulin antibodies commonly develop in diabetic patients who use subcutaneous human insulin, although their clinical significance remains controversial. Few data are available regarding insulin antibody responses to intraperitoneal insulin. RESEARCH DESIGN AND METHODS: We studied insulin antibody levels and clinical diabetes control in 25 type 1 diabetic patients treated for 3-6 years with intraperitoneal surfactant-stabilized porcine modified human insulin delivered by implantable programmable insulin delivery systems. RESULTS: All patients had preimplantation insulin antibody levels < 20 microU/ml, with a mean value of 2 +/- 2 microU/ml (1 SD). Mean antibody levels increased throughout the study period to a mean maximum of 197 +/- 326 microU/ml (P < 0.02) with 11 of 25 (44%) patients' levels exceeding 20 microU/ml (insulin responders). The mean time to significant antibody development was 21.8 +/- 4.4 months. Of the 11 responder patients, 4 had clinical syndromes that consisted of increasing daily insulin requirements and/or nocturnal hypoglycemia despite minimal nighttime basal insulin infusion rates associated with peak antibody levels > 200 microU/ml. None of the nonresponder patients (antibody levels < 20 microU/ml) had these clinical findings. CONCLUSIONS: Our results indicate that insulin antibody levels observed during intraperitoneal administration of human insulin are 1) similar to those reported during subcutaneous administration; although the rise in antibody level may be delayed compared with subcutaneous human insulin, 2) associated with a patient subset who are insulin antibody responders after switching from subcutaneous to intraperitoneal human insulin, 3) associated with a decrease in levels among responder patients regardless of whether they discontinue or continue pump use, and 4) associated with increased insulin needs and/or nocturnal hypoglycemia despite minimal basal rate insulin infusion at nighttime when antibody levels exceed 200 microU/ml.

Correlates of blood pressure in community-dwelling older adults. The Cardiovascular Health Study. Cardiovascular Health Study (CHS) Collaborative Research Group.

Although elevated blood pressure is an important predictor of cardiovascular disease and stroke in the elderly, little information exists on the distribution and risk factor correlates of blood pressure in this group. As part of the Cardiovascular Health Study, a population-based cohort study of 5201 men and women aged 65 to 101 years, we investigated correlates of systolic and diastolic blood pressure. Multiple regression analyses were conducted for all participants and a subgroup of 2482 without coronary heart disease and not on antihypertensive therapy (the "healthier" subgroup). In the total group, independent predictors of diastolic blood pressure included heart rate, aortic root dimension, creatinine, hematocrit, alcohol use, and black race (positive associations) and internal carotid artery wall thickness, mitral early/late peak flow velocity, white blood cell count, cigarette smoking, and age (negative associations). Positive predictors of systolic blood pressure included mitral late peak flow velocity, left ventricular mass, common carotid artery wall thickness, serum albumin, factor VII, diabetes, alcohol use, and age; negative predictors were coronary heart disease, uric acid, height, and smoking. In the healthier subgroup, positive predictors of diastolic blood pressure included heart rate, hematocrit, serum albumin, creatinine, and body weight, whereas mitral early/late peak flow velocity, serum potassium, smoking, and age inversely related to diastolic pressure. For the same group, common carotid artery wall thickness, left ventricular mass, serum albumin, factor VII, high-density lipoprotein cholesterol, and age were directly related to systolic blood pressure, whereas serum potassium was inversely related. Both systolic and diastolic pressures varied considerably by geographic site.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular mass in the elderly. The Cardiovascular Health Study.

Left ventricular (LV) mass, as estimated from M-mode echocardiography (echo), has previously been shown to be an independent predictor of incident cardiovascular disease morbidity and mortality. We evaluated the relationship at baseline of echo LV mass to relevant cardiovascular disease risk factors and other potential covariates in the Cardiovascular Health Study, multicenter study sponsored by the National Heart, Lung, and Blood Institute of 5201 men and women aged 65 years or older (mean, 73). Two-dimensionally directed M-mode echo LV mass measurements could be obtained in 1357 men and 2053 women (66% of this elderly cohort). Stepwise linear regression analyses of the relationship of echo LV mass to demographic and risk factor, physical activity, electrocardiographic, and prevalent disease variables resulted in a model that explained 37% of the variance for the entire cohort. In order of decreasing importance, factors positively associated with echo LV mass were body weight, male sex, systolic pressure, presence of congestive heart failure, present smoking, major and minor electrocardiographic abnormalities, treatment for hypertension, valvular heart disease, aortic regurgitation by color Doppler, and mitral regurgitation by color Doppler (in men) whereas diastolic pressure, bioresistance (a measure of adiposity), and high-density lipoprotein cholesterol were inversely related to echo LV mass. Although height and weight were both related to LV mass, height added nothing once weight was entered in multiple linear regression analyses. Furthermore, in the multiple regression models, diastolic pressure was inversely and systolic BP positively related to LV mass, with similar magnitudes for their coefficients. In consonance with these findings, pulse pressure was positively related to LV mass in bivariate analyses. Multiple linear regression analyses explained less of the variance for ventricular septal thickness (R2 = .13) and LV posterior wall thickness (R2 = .14) than for LV mass (R2 = .37) and LV diastolic dimension (R2 = .27). Intriguing findings in the elderly Cardiovascular Health Study cohort included the presence of pulse pressure as a positive correlate, and high-density lipoprotein cholesterol as an inverse correlate, of LV mass. Longitudinal studies in the Cardiovascular Health Study cohort will help to clarify the importance of demographic, risk factor, and other variables, and changes in these variables, in predicting changes in echo LV mass and its components as well as the prognostic significance of LV mass in the elderly.

Prognostic significance of coronary calcific deposits in asymptomatic high-risk subjects.

PURPOSE: To determine the predictive value of coronary calcifications for coronary heart disease events in high-risk, asymptomatic adults: PATIENTS AND METHODS: A prospective cohort study of 1,461 high-risk, asymptomatic subjects were followed for 55 months with a 98% success rate. Coronary risk factor assessment and cardiac fluoroscopy with digital subtraction enhancement were performed to determine the number of calcified coronary arteries. RESULTS: Fifty-eight percent of this cohort (852 subjects) had fluoroscopically detectable coronary calcification: 437 (30%) had calcium in one, 253 (17%) in two, and 162 (11%) in all three coronary vessels. There were 90 (6%) deaths, 35 (39%) attributable to coronary heart disease, and 43 (3%) nonfatal myocardial infarctions. Subjects with calcification in more than one major coronary artery were 2.2 times more likely to suffer coronary death or nonfatal infarction (P = 0.001) than were subjects with one or no calcified arteries. Multivariable logistic regression analysis showed that only the number of calcified arteries, age, total cholesterol, history of diabetes, and left ventricular hypertrophy by electrocardiogram were associated independently with the incidence of coronary death or infarction in these subjects. CONCLUSIONS: Coronary calcification predicts coronary heart disease death or infarction in high-risk asymptomatic adults as well as do standard risk factors.

Television viewing and pediatric hypercholesterolemia.

Cholesterol screening for children is recommended currently only for those with a family history of premature coronary heart disease or hyperlipidemia. The authors report on a pediatric-office-based cholesterol screening program where the predictive values of family history indicators were evaluated along with reported television viewing, physical activity, and dietary habits in 1081 children (aged 2 to 20 years, mean 7.4 +/- 3.6 [SD] years). Eight percent of these children had a total cholesterol value of 200 mg/dL or higher; 53% of such children reported watching 2 or more hours of television daily compared with 34% of children with lower cholesterol levels. Multivariate analyses revealed that excessive television viewing was the strongest predictor for a child to have a cholesterol value of 200 mg/dL or higher, with relative risks of 2.2 for 2 to 4 hours of television viewing per day (P less than .01) and 4.8 for children watching more than 4 hours/day, when compared to those watching less than 2 hours/day (P less than .01). In contrast, a positive family history of a high cholesterol level was only modestly associated with an increased probability of having a high cholesterol level (relative risk = 1.6, P less than .05), and a history of premature myocardial infarction in a parent or grandparent was not associated with a child's cholesterol level. Excessive television viewing was found to be associated with certain dietary and physical activity habits and may prove to be a useful, global marker for several life-style factors predisposing children to hypercholesterolemia.

Alcohol consumption, coronary calcium, and coronary heart disease events.

This study was performed to determine if alcohol intake was associated with reduced coronary risk in a high-risk asymptomatic population, and whether this effect was independent of coronary risk factors and coronary calcium. In 1,196 asymptomatic subjects with coronary risk factors, we assessed alcohol consumption history, performed risk factor measurements, and quantified coronary calcium with electron beam computed tomography. These subjects were then followed for a mean of 41 months, and coronary events (myocardial infarction or coronary death) were noted. Significant inverse predictors of coronary events included alcohol use and serum high-density lipoprotein cholesterol level. Direct predictors of events were history of systemic hypertension, smoking, diabetes mellitus, serum cholesterol, and coronary calcium score. Subjects with coronary calcium were 3.1 times more likely to suffer a coronary event than those without calcium (95% confidence interval [CI] limits 1.3 to 7.2). Subjects who drank alcohol had a relative risk of 0.3 (95% CI limits 0.2 to 0.6) for developing coronary events. After controlling for age, gender, and other risk factors with logistic regression, these differences in relative risk persisted (relative risk 0.58; 95% CI limits 0.41 to 0.82). Alcohol consumption is a significant inverse predictor of coronary events, comparable in magnitude to standard risk factors and to radiographically measured coronary calcium. This effect is independent of coronary risk factors and coronary calcium.

Risk factor correlates of coronary calcium as evaluated by ultrafast computed tomography.

Coronary artery calcium is invariably associated with atherosclerosis and has been linked to an increased risk of coronary events. Ultrafast computed tomography (CT) was recently used to document the presence and relative quantity of coronary calcium. The use of the self-reported coronary risk factors to identify persons with coronary calcium as documented by ultrafast CT screening was examined in 458 men and 139 women aged 26 to 81 years (88% asymptomatic). All subjects underwent ultrafast CT scanning, and received a questionnaire and underwent an interview regarding medical and risk factor history. Total calcium score was calculated as the sum of lesion-specific scores, each calculated as the product of density > or = 130 Hounsfield units and area > or = 0.51 mm2. The prevalence of coronary calcium increased significantly (p < 0.01) by age group, and the greater the number of risk factors present, the greater the likelihood of calcium. From multiple logistic regression, age (p < 0.01), male sex (relative risk [RR] 3.03; p < 0.01), and history of smoking (RR 1.85; p < 0.01) and hypertension (RR 1.65; p < 0.05) were independently associated with the probability of detectable calcium. Among asymptomatic subjects, an association with hypercholesterolemia was also seen (RR 1.56; p < 0.05). The results demonstrate that cardiovascular risk factors can help in identifying the likelihood of coronary calcium.

Coronary artery calcium evaluation by electron beam computed tomography and its relation to new cardiovascular events.

Electron beam computed tomography is widely used to screen for coronary artery calcium (CAC). We evaluated the relation of CAC to future cardiovascular disease events in 926 asymptomatic persons (735 men and 191 women, mean age 54 years) who underwent a baseline electron beam computed tomographic scan. All subjects included in this report returned a follow-up questionnaire 2 to 4 years (mean 3.3) after scanning, inquiring about myocardial infarction, stroke, and revascularizations. Sixty percent of men and 40% of women had a positive scan at baseline. Twenty-eight cardiovascular events occurred and were confirmed by blinded medical record review. The presence of CAC (a total calcium score of >0) and increasing score quartiles were related to the occurrence of new myocardial infarction (p <0.05), revascularizations (p <0.001), and total cardiovascular events (p <0.001). Those with scores at or above the median (score of 5) had a relative risk of 4.5 (p <0.01) for new events. From Cox regression models, adjusted for age, gender, and coronary risk factors, the relative risks for those with scores of 81 to 270 and -271 (compared with 0) for cardiovascular events were 4.5 (p <0.05) and 8.8 (p <0.001), respectively. These data support previous reports showing CAC to be a modest predictor of future cardiovascular events.

Detection of coronary artery calcium by ultrafast computed tomography and its relation to clinical evidence of coronary artery disease.

Ultrafast computed tomography (CT) was used to evaluate the relation of coronary artery calcium, a marker of atherosclerosis, with a reported history of coronary artery disease (CAD) in 928 men and 290 women (mean age 53 +/- 10 years; 11% with previous CAD). Total calcium score was calculated as the sum of each lesion-specific score, calculated as the product of pixel area and density > 130 Hounsfeld units. Total score was 3 to 6 times greater (p < 0.01) and the probability of coronary artery calcium 30 to 40% greater (p < 0.01) in patients with a reported history of myocardial infarction, positive angiography, bypass surgery or angioplasty. From score cutoffs ranging from 1 to 500 for defining calcium, a negative test was accurate 93 to 98% of the time in ruling out CAD, whereas specificity increased from 43 to 93%; however, sensitivity decreased from 92 to 42%. A score cutoff of 50 showed modest sensitivity (78%) and specificity (71%); however, the predictive value for CAD from a positive test remained low (< or = 40%), regardless of score cutoff. From multiple logistic regression, total score was also an independent indicator of CAD after considering any effects due to age, sex and other CAD risk factors. Further study is needed to document the long-term prognostic use of coronary calcium screening, including criteria that best project future risk of CAD.