The Association of Lung Function and Carotid Intima-Media Thickness in a Japanese Population: The Tohoku Medical Megabank Community-Based Cohort Study

AIM

Impaired lung function is associated with atherosclerotic vascular events. Carotid intima-media thickness (cIMT) is a marker for subclinical atherosclerosis. However, few studies have examined the association between lung function and cIMT among never smokers or individuals stratified by age. We investigated the association between lung function and cIMT in the Japanese population.

METHODS

We conducted a cross-sectional study of 3,716 men and 8,765 women aged 20 years or older living in Miyagi Prefecture, Japan. Lung function was evaluated using forced expiratory volume at 1 s (FEV1) and forced vital capacity (FVC) was measured using spirometry. The maximum common carotid artery was measured using high-resolution B-mode ultrasound. An analysis of covariance was used to assess associations between lung function and cIMT and adjusted for potential confounders. A linear trend test was conducted by scoring the categories from 1 (lowest) to 4 (highest) and entering the score as a continuous term in the regression model.

RESULTS

After adjusting for potential confounders including passive smoking, lower FEV1 and FVC were associated with higher cIMT in both men and women (P＜0.001 for linear trend). This association was confirmed even when we restricted our study to never smokers. Furthermore, even when we stratified by age, an inverse association between lung function and cIMT was confirmed in middle-aged (40-64 years) and elderly participants (65-74 years).

CONCLUSIONS

Lower lung function was associated with higher cIMT in the Japanese population independent of age and smoking. Assessment of atherosclerosis or lung function may be required for individuals with lower lung function or atherosclerosis.

Second-hand smoking, hypertension and cardiovascular risk: findings from Peru

Background

Second-hand smoking has not been detailedly studied in Peru, where smoking is prohibited in all indoor workplaces, public places, and public transportation. Second-hand smoke exposure may occur at home or any other places. This study aimed to estimate the prevalence of second-hand smoking and assess its association with hypertension and cardiovascular risk in Peru.

Materials and methods

Secondary analysis of a nationally-representative population-based survey including individuals aged 18–59 years. There were two outcomes: hypertension and 10-year cardiovascular risk using the Framingham and the 2019 World Health Organization (WHO) risk scores. The exposure was self-reported second-hand smoking during the 7 days before the survey. The association between second-hand smoking and hypertension was quantified with Poisson models reporting prevalence ratio (PR) and 95% confidence interval (95% CI); the association between second-hand smoking and cardiovascular risk was quantified with linear regressions reporting coefficients and their 95% CI.

Results

Data from 897 individuals, mean age: 38.2 (SD: 11.8) years, and 499 (55.7%) females, were analyzed, with 8.7% subjects reporting second-hand smoking at home and 8.3% at work or any other place. Thus, 144 (15.5%; 95% CI: 12.8%-18.6%) subjects reported any second-hand smoking. In multivariable model second-hand smoking was associated with hypertension (PR = 2.42; 95% CI: 1.25–4.67), and with 1.2% higher Framingham cardiovascular risk, and 0.2% higher 2019 WHO risk score.

Conclusions

There is an association between second-hand smoking and hypertension as well as with cardiovascular risk, and 15% of adults reported second-hand smoke exposure overall with half of them exposed at home. There is a need to guarantee smoking-free places to reduce cardiovascular risk.

Carotid intima media thickness is in a relation to risk factors for coronary artery disease

INTRODUCTION

Carotid intima-media thickness (CIMT) is a double line pattern measured from the lumen-intima to media-adventitia interface. Measuring CIMT with B-mode ultrasound can detect early arterial wall changes. We aimed to measure CIMT in manifested atherosclerotic disease and find a relation to present risk factors.

MATERIAL AND METHODS

This cross sectional study included a population of 657 patients, with documented coronary artery disease (CAD), 66,1% were men (469 pts), 33,9% were women (241 pts). The mean age of patients was 64,72 years (55,6-73,8). The measurement of CIMT (maximal and mean) was performed with B-mode ultrasound, on longitudinal view, on multiple plaque-free segments at the level of common carotid artery, on the far wall, on both sides. Multivariate regression analysis was done to estimate independent factors for CIMT, when risk factors, age, and sex included in analysis.

RESULTS

The mean value of maximal CIMT was 0,96 mm (0,52-1,4), mean value of mean CIMT was 0,88 mm (range 0,61-1,15) and mean systolic blood pressure of 133,21 mm Hg (108,03-158,39) was found. Increased CIMT was found in 75,7% of patients (502 pts). Smoking was found as an independent risk factor for increased CIMT with odds ratio (OR) 4,7 (95% CI; 0,67-5,32) and diabetes mellitus with OR 1,6 (95% CI; 0,47-2,16).

CONCLUSION

Diabetes and smoking are independently related to increased CIMT. These are preliminary results of National survey on 657 pts with coronary artery disease.

High prevalence of ultrasound detected carotid atherosclerosis in subjects with low Framingham risk score: potential implications for screening for subclinical atherosclerosis

BACKGROUND

The cardiovascular (CV) risk assigned by the Framingham risk score (FRS) misses many subjects destined for CV events. Coronary artery calcification (CAC) as measured by computed tomography and carotid intima-media thickness (CIMT) and plaque assessment using B-mode ultrasound can identify subclinical atherosclerosis. The comparative relation of CAC and CIMT and carotid plaque after integration into the FRS is not established. The aim of this study was to develop a CV screening approach incorporating FRS, CAC, and CIMT.

METHODS

The prevalence of subclinical atherosclerosis, defined as CAC score > 0, CIMT > or = 75th percentile, or plaque > or = 1.5 mm, was determined in the groups with low, intermediate, and high FRS among 136 asymptomatic subjects. The CIMT and CAC values were used to determine "vascular age" and "coronary calcium" age, respectively, with established nomograms.

RESULTS

In the 103 low-risk (FRS < 10%) subjects, 41%, 50%, 59%, and 66% had CAC scores > 0, CIMT > or = 75th percentile, plaque > or = 1.5 mm, and CIMT > or = 75th percentile or plaque > or = 1.5 mm, respectively. In the 33 subjects with intermediate (n = 14) or high (n = 19) FRS, 70%, 81%, 87%, and 87% had CAC scores > 0, CIMT > or = 75th percentile, plaque > or = 1.5 mm, and CIMT > or = 75th percentile or plaque > or = 1.5 mm, respectively. Fifty-two percent of subjects with coronary calcium scores of zero had carotid plaque. Adjusted for FRS, body mass index was an independent predictor of abnormal CIMT in the low-FRS group, but not of abnormal CAC. Mean vascular CIMT age was significantly higher than coronary calcium age (61.6 + or - 11.4 vs 58.3 + or - 11.1 years, P = .001), and both were significantly higher than chronologic age (56.9 + or - 10.1 years) (P < .0001 and P < .04, respectively). CIMT upgraded or downgraded FRS by >5% in more cases than CAC (42% vs 17%).

CONCLUSION

In asymptomatic patients without CV disease, CIMT and plaque assessment are more likely to revise FRS than CAC. Body mass index predicts increased CIMT in low-FRS subjects. These findings may have broad implications for screening in low-FRS subjects.

Smoking and smoking cessation -- the relationship between cardiovascular disease and lipoprotein metabolism: a review

Cigarette smoking is generally accepted as the most preventable cause of death in the United States today. Individuals who smoke experience a wide range of physiologic side effects that increase the risk of cardiovascular disease (CVD), including insulin resistance, elevated catecholamine levels which contribute to an elevated heart rate and blood pressure, and hypercholesterolemia. The link between hypercholesterolemia and cardiovascular disease has been extensively researched and is undeniable. What is more, this link is strengthened in smokers as cigarette smoking is known to increase total cholesterol (TC), triglycerides (TG), and low-density lipoprotein (LDL), while acting to decrease the cardio-protective high-density lipoprotein (HDL). Alterations in the enzymes that control lipid transport may be a key underlying mechanism contributing to these health destroying effects. This review examines the current literature related to: (1) smoking, lipoproteins, and lipid-related enzymes; (2) the impact of nicotine, carbon monoxide and free radicals on physiologic parameters related to health; and (3) metabolic issues involving smoking cessation and nicotine replacement therapy.

Carotid intima-media thickness in patients with liver cirrhosis associated with diabetes mellitus

OBJECTIVE

In patients with liver cirrhosis (LC), the incidence of diabetes mellitus (DM) is high, whereas that of hypertension and ischemic heart diseases is low. We measured carotid artery intima-media thickness (IMT) to determine the incidence of atherosclerosis in patients with LC+DM and to compare it with that in patients with type 2 DM, and evaluated the risk factors for atherosclerosis in these patients.

RESEARCH DESIGN AND METHODS

We determined IMT of the common carotid artery by B-mode ultrasound, serum lipid levels, C-reactive protein (CRP), plasma levels of fasting and postprandial glucose, glycated hemoglobin (HbA1c), fibrinogen and platelet counts in 14 patients of the LC+DM group, 16 patients with type 2 DM (DM group) and 14 patients with LC without impaired glucose tolerance (LC group).

RESULTS

The IMT in the LC+DM group (0.694+/-0.175mm) was similar to that in the LC group (0.693+/-0.151mm) but significantly smaller than the DM group (0.904+/-0.337mm). There were no significant differences between the LC+DM group and DM group in the duration of DM, proportion of smokers, arterial blood pressure, fasting and postprandial plasma glucose levels, and CRP, but HbA1c, platelet counts and fibrinogen were significantly lower in the LC+DM group than in the DM group.

CONCLUSIONS

Our study suggests that the development of atherosclerosis in patients with DM is suppressed by the presence of LC, probably due to reduced platelet counts and fibrinogen levels.

[Cigarette smoking in military pilots and intima-media thickness of the carotid arteries]

BACKGROUND

It is well known that smoking is associated with an increase in arterial wall thickness. However, most studies of this problem have been undertaken in age and sex heterogenous groups, as well as in patients with already present other conventional risk factors. The aim of this study was to assess the effect of cigarette smoking on arterial wall thickness of the common carotid artery in asymptomatic pilots.

METHODS

The imaging of intima-media thickness of the posterior wall of the distal 1 cm of both common carotid arteries was performed using a B mode ultrasound device, in 39 pilots (37.05 +/- 6.66 years), for whom smoking was the single cardiovascular risk factor. Comparisons were made with 49 non-smokers (35.12 +/- 7.39 years).

RESULTS

The posterior walls of both common carotid arteries were thicker in smokers (left, p < 0.05; right, p > 0,05). Intima-media thickness was significantly lower on the right side than on the left side in both smokers and non-smokers (p < 0.01).

CONCLUSION

Cigarette smoking as the single cardiovascular risk factor was associated with the wall thickness of the carotid arteries in our study. This finding indicated that early atherosclerosis was already present in pilots-smokers entering middle age.

Environmental tobacco smoke and carotid arterial stiffness

BACKGROUND

Although active smoking acutely increases arterial stiffness, the association between arterial stiffness and chronic exposure to environmental tobacco smoke (ETS) has not been evaluated. We used baseline data from the Vitamin E Atherosclerosis Prevention Study to evaluate the association between ETS exposure and arterial stiffness among 227 healthy adult nonsmokers.

METHODS

B-mode ultrasonograms of the common carotid artery were used to compute the carotid arterial wall stiffness index beta. Beta was compared by the number of sources and daily hours of ETS exposure.

RESULTS

The carotid stiffness index beta was positively associated with age, body mass index (BMI), fasting glucose, and common carotid artery intima-media thickness (IMT). In the total sample, beta was not related to the number of ETS exposure sources. The carotid stiffness index beta increased with number of sources and daily hours of ETS in subjects with BMI > or =27.1 kg/m2 and IMT > or =0.707 mm. The association was not apparent in subjects with lower BMI or IMT (for number of ETS sources, interaction P values=0.006 and 0.01, respectively). For number of ETS sources, but not hours of exposure, positive associations were apparent among females (but not males) and among subjects > or =55 years old (but not younger subjects).

CONCLUSIONS

These data indicate that arterial stiffness is adversely associated with ETS in a dose-dependent manner among individuals with higher BMI and greater carotid artery IMT.

The carotid artery as a noninvasive window for cardiovascular risk in apparently healthy individuals

Cardiovascular diseases are the leading cause of death and disability in industrialized countries. Because the etiologies are related to alteration of arterial wall properties, the noninvasive evaluation could help the presymptomatic diagnosis and potentially the prevention of future events. Ultrasound (US) is currently the only modality to image the arterial wall in real-time with sufficient resolution to allow for observation of its morphological, hemodynamic and elastic properties. Increased wall thickness and atheromatous plaques of carotid arteries are associated with cardiovascular risk factors and diseases. Also, carotid Doppler waveforms and wall elasticity may have associations with arterial health. Although evaluation of these arterial properties are currently limited to the research laboratories, most of such properties can be evaluated in the standard setting of carotid ultrasonography. This article reviews "potential" utilities of carotid US evaluation for cardiovascular risk assessment in apparently healthy individuals.

The association of atherosclerosis, vascular risk factors, and retinopathy in adults with diabetes : the atherosclerosis risk in communities study

PURPOSE

The aim of this report is to describe the prevalence of retinopathy and its associations with atherosclerosis and vascular risk factors in people with diabetes.

DESIGN

Cross-sectional study.

PARTICIPANTS

Persons with diabetes, having gradable fundus photographs, from a biracial population-based cohort of adults (ages 51-72 years), and living in four United States communities (Forsyth County, North Carolina; the city of Jackson, Mississippi; suburbs of Minneapolis, Minnesota; and Washington County, Maryland) were studied from 1993 to 1995.

METHODS

Lesions typical of diabetic retinopathy were detected by grading a 45 degrees color fundus photograph of one eye of each participant, using a modification of the Airlie House classification system.

MAIN OUTCOME MEASURE

Severity of diabetic retinopathy (none, minimal nonproliferative, moderate nonproliferative, severe nonproliferative, and proliferative) and macular edema.

RESULTS

Retinopathy was detected in 328/1600 (20.5%) of those with diabetes; 114/1724 (6.6%) had hard exudate, 28/1600 (1.8%) had proliferative diabetic retinopathy, and 27/1662 (1.6%) had macular edema. The prevalence of diabetic retinopathy was higher in blacks (27.7%) compared with whites (16.7%). Controlling for duration of diabetes, serum glucose, systolic blood pressure, and type of diabetes medications taken, severity of retinopathy was associated with carotid artery intima-media wall thickness (odds ratio [OR]/0.1-mm thickness 1.09; 95% confidence interval [CI], 1.01, 1.17; P = 0.01), serum albumin (OR/0.1 g/dl 0.94; 95% CI, 0.88, 0.99; P = 0.02), but not race (OR blacks versus whites,1.24; 95% CI, 0.88, 1.75; P = 0.21). Severity of diabetic retinopathy was not associated with coronary artery disease or stroke history or any of the plasma lipids studied. Controlling for age, gender, duration of diabetes, serum glucose, and type of diabetes medications taken, the presence of retinal hard exudates was associated with plasma low-density lipoprotein cholesterol (OR/10 mg/dl 1.18; 95% CI, 1.09, 1.29; P < 0.001), and plasma Lp(a) (OR/10 mg/dl 1.02; 95% CI, 1.00, 1.05; P = 0.04) but not race or blood pressure.

CONCLUSIONS

These data suggest that plasma lipids are associated with the presence of hard exudate and that carotid artery intima-media wall thickness is associated with retinopathy, but other manifestations of atherosclerosis and most of its risk factors are not associated with severity of diabetic retinopathy.

The effect of cigarette smoking on soluble adhesion molecules in middle-aged patients with Type 2 diabetes mellitus

AIMS

To investigate the effect of smoking on soluble adhesion molecules in middle-aged diabetic patients.

METHODS

One hundred out-patients with Type 2 diabetes and 100 age- and sex-matched non-diabetic subjects without clinical macrovascular disease were selected. Soluble serum levels of adhesion molecules were analysed using enzyme immunoassay. Carotid atherosclerosis was assessed using an ultrasound system.

RESULTS

When compared with non-diabetic subjects, soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and sE-selectin were found at significantly high levels in diabetic patients and significantly higher levels of sICAM-1, sE-selectin, and sP-selectin were observed in current smokers than never-smokers among diabetic or non-diabetic subjects, respectively. The combined, but not enhanced, effects of diabetes mellitus and smoking were observed in sICAM-1 and sE-selectin levels. Additionally, levels of sICAM-1 (P < 0.05) and sE-selectin (P < 0.01), but not sP-selectin, were high in ex-smokers when compared with never-smokers among diabetic patients. Diabetic smokers were also found to have marked carotid atherosclerosis, which was related to increased levels of sICAM-1.

CONCLUSIONS

Our present study shows that levels of adhesion molecules were higher in diabetic smokers than diabetic non-smokers or non-diabetic smokers, and that cessation after chronic smoking did not restore the levels of sICAM-1 and sE-selectin, though sP-selectin levels were restored. These data suggest a possible mechanism for accelerated atherosclerosis induced by smoking in patients with diabetes.

Decrease in carotid intima media thickness after 1 year of cilostazol treatment in patients with type 2 diabetes mellitus

A multicenter exploratory study at three university hospitals was performed to evaluate the effect of oral cilostazol on intima media thickness (IMT) in diabetic patients. A total of 141 patients was recruited in this study and randomized into a cilostazol group and a placebo (control) group. One hundred and twenty patients completed the study (i.e. 60 on cilostazol and 60 on placebo). Biochemical profiles and the IMT of the common carotid artery (CCA) determined by high-resolution B-mode ultrasonography were measured at 0, 6, and 12 months after the oral administration of 100--200 mg of cilostazol or placebo (i.e. two or four times daily for 12 months). Clinical and biochemical characteristics, the treatment modality, and microvascular diabetic complications after randomization were not significantly different between the two groups after the study. In the cilostazol treatment group, left CCA average IMT significantly decreased from 0.94+/-0.03 to 0.91+/-0.02 mm at 6 months (P<0.05), and thereafter increased to 0.92+/-0.01 mm (P>0.05) at 12 months, whereas in the control group, it increased from 0.92+/-0.03 to 0.93+/-0.01 mm at 6 months (P>0.05), and to 0.94+/-0.01 mm at 12 months (P>0.05). As for the right CCA average IMT, it decreased from 0.83+/-0.03 to 0.82+/-0.01 mm at 6 months (P<0.05), and to 0.81+/-0.01 mm at 12 months (P<0.05) in the cilostazol group, whereas it increased from 0.87+/-0.03 to 0.89+/-0.01 mm at 6 months (P<0.05), and to 0.90+/-0.01 mm at 12 months (P<0.05) in the control group (P<0.05). After correction for risk factors such as blood pressure, smoking, and lipid profiles, there were significant changes in left and right CCA average IMT for both groups (P<0.05). Left and right CCA average IMT was significantly different between the two groups (P<0.05). After making statistical corrections for blood pressure, smoking, and lipid profiles, the differences between these two groups remained significant (P<0.05). Meanwhile, there were no differences between the groups in the change of risk factors such as BMI, blood pressure, blood sugar, HbA(1c), and lipid profiles. Generally, cilostazol was well tolerated and the most common side effect in the cilostazol group was headache (12/60), mostly early in the treatment regimen. The results suggest that oral cilostazol may be helpful in the treatment of atherosclerosis in type 2 diabetic patients, although conventional cardiovascular risk factors remained unmodified.

Smoking characteristics, antioxidant vitamins, and carotid artery wall thickness among life-long smokers

We studied the associations between the common carotid-intima-media thickness (IMT), as a marker of atherosclerosis, and smoking characteristics and antioxidant vitamins among 158 male life-long cardiovascular disease (CVD)-free smokers. An "increased" carotid IMT was defined as the upper 25%. The prevalence of increased IMT was 2.5 times (odds ratio (OR) = 2.5; 95% CI: 1.1, 5.6) higher among smokers inhaling smoke deeply into the lungs than among moderate and non-inhalers. This association decreased when adjusted for other CVD risk factors. Smokers with an increased carotid IMT did not differ significantly in mean antioxidant vitamin intake and status with the remaining group. However, classical CVD risk factors contributed importantly to increased carotid IMT. In our study, depth of inhalation was the only smoking characteristic associated with carotid IMT although attenuated after adjustment for traditional risk factors for CVD. Furthermore, in these life-long smokers not using any vitamin supplements, no associations were found for antioxidant vitamins.

Intima-media thickness of peripheral arteries in asymptomatic cigarette smokers

BACKGROUND AND PURPOSE

Although it is known that smoking is associated with an increase in arterial wall thickness, most studies have been performed in heterogeneous groups of older age, already suffering from atherosclerotic diseases or having additional cardiovascular risk factors. The purpose of this study is to assess the effect on arterial wall thickness of the carotid and femoral artery in cigarette smokers.

METHODS

In a cross-sectional study, intima-media thickness of the common and internal carotid artery, carotid bulb and common femoral artery was determined with the use of a B-mode ultrasound device, in 184 (44.3+/-9.0 years) cigarette smokers for whom smoking is the single cardiovascular risk factor. Comparisons were made with 56 non-smokers, matching in age and gender.

RESULTS

The posterior walls of both carotid bulbs (right: P=0.0005; left: P=0.02) and of the internal carotid arteries (right: P=0.004; left: P=0.003) as well as the posterior wall of the right common carotid artery (P=0.02) and of the right common femoral artery (P<0.0001) were thicker in smokers.

CONCLUSIONS

Cigarette smoking as the single cardiovascular risk factor causes wall thickening of the carotid and femoral arteries, which indicates that early atherosclerosis is already present in smokers entering middle age.

Measures of exposure to environmental tobacco smoke. Validity, precision, and relevance

It is often not clear what the best measures of exposure are for a risk assessment, or even how one should answer this question. Environmental tobacco smoke (ETS) provides a good example for an exploration of uncertainty. There are a variety of methods for estimating exposure and each has short-comings. In this paper we summarize the physical characteristics of ETS and the principal methods for assessing exposure. We review the accuracy and applicability of these methods, and explore major sources of uncertainty in the assessment of ETS.

Cigarette smoking, environmental tobacco smoke exposure and insulin sensitivity: the Insulin Resistance Atherosclerosis Study

PURPOSE

To investigate whether active smoking and/or exposure to environmental tobacco smoke (ETS) is associated with insulin sensitivity.

METHODS

Insulin sensitivity and tobacco use history were measured in 1481 participants in the Insulin Resistance Atherosclerosis Study (IRAS). IRAS is a large mulitcenter epidemiologic study designed to explore the cross-sectional relationships among insulin resistance, cardiovascular disease risk factors and behaviors, and disease in African-American, Hispanic, and non-Hispanic white men and women, aged 40-69 years, selected to represent a broad range of glucose tolerance. Multiple linear regression models and linear contrasts were employed to describe the association between smoking history, as assessed via structured interview, and insulin sensitivity, as assessed by an insulin modified frequently sampled intravenous glucose tolerance test (FSIGT) with minimal model analysis.

RESULTS

Active smoking was not associated with insulin sensitivity. Exposure to ETS was associated with lower insulin sensitivity. Specifically, for all participants combined, levels of SI were lower, indicating reduced insulin sensitivity, for those exposed to ETS when compared to those who were not exposed (p = 0.019). This association persisted for female participants (p = 0.013) and exhibited the same trend for males but failed to achieve statistical significance (p = 0.264).

CONCLUSIONS

Our study did not reveal an association between active smoking and insulin sensitivity, as has been shown previously. The association between ETS exposure and insulin sensitivity is a puzzling finding which deserves further investigation in the longitudinal data from IRAS as well as in other populations.

Apolipoprotein E4, lipoprotein lipase C447 and angiotensin-I converting enzyme deletion alleles were not associated with increased wall thickness of carotid and femoral arteries in healthy subjects from the Stanislas cohort

Studies have shown contrasting results concerning the relation between carotid intima-media thickness (IMT) and apolipoprotein E (apo E) and angiotensin-converting enzyme (ACE) polymorphisms. Subjects, 76 men and 74 women, between 33 and 50 years, without any history of cardiovascular disease and without any anti-hypertensive or lipid lowering medication were selected from the Stanislas cohort. The IMT of carotid and femoral arteries were investigated by B-mode ultrasonography. The common apo E, (C/G)447 lipoprotein lipase (LPL) and I/D ACE gene polymorphisms and serum ACE activity were determined. In the overall sample, male sex, age, systolic blood pressure, BMI, serum apo B level and tobacco consumption were positively correlated with carotid and femoral IMT. The common apo E polymorphism, the (C/G)LPL447 polymorphism and ACE activity were not related to carotid and femoral IMT variability in either men or women. Unexpectedly, the I allele of the ACE gene was related to higher femoral IMT than the D allele in non-smokers only. Similar results were observed after adjustment for the main covariates of IMT variability. In conclusion, amongst our young adult sample the candidate risk factors for cardiovascular disease, apo epsilon4, C447-LPL and D-ACE alleles and ACE activity were not associated with increased carotid and femoral IMT.

Carotid artery and left ventricular structural relationship in asymptomatic men at risk for cardiovascular disease

To determine whether a relationship between echographically assessed carotid artery and left ventricular (LV) structures existed in asymptomatic men at risk for cardiovascular disease, we evaluated carotid and LV parameters in 69 subjects (23-62 years) without LV hypertrophy. The right common carotid far wall intima-media thickness (IMT) was measured using an automated technique and the cross-sectional intima-media complex area (IMC-CSA) was calculated, assuming a circular profile of carotid wall layers, as (IMC-CSA = pi x IMT x (IMT + D)), D being the lumen diameter. LV mass was evaluated using the M-mode echocardiography. Among study subjects 30% were hypertensive, 67% hypercholesterolemic, 21% current smokers and 52% had a positive smoking history. In the study population LV mass correlated both with IMT (r = 0.54, P < 0.001) and IMC-CSA (r = 0.62, P < 0.001). In multivariate analysis LV mass was associated with IMC-CSA (P < 0.001), body mass index (P < 0.01), lifelong smoking dose (P < 0.01) and systolic blood pressure (P < 0.05), r2 = 0.58, P < 0.001. Therefore, IMC-CSA may be a clinically relevant independent indicator of LV mass even within its normal ranges.

Passive smoking and impaired endothelium-dependent arterial dilatation in healthy young adults

BACKGROUND

Passive smoking has been linked to an increased risk of dying from atherosclerotic heart disease. Since endothelial dysfunction is an early feature of atherogenesis and occurs in young adults who actively smoke cigarettes, we hypothesized that passive smoking might also be associated with endothelial damage in healthy young-adult nonsmokers.

METHODS

We studied 78 healthy subjects (39 men and 39 women) 15 to 30 years of age (mean +/- SD, 22 +/- 4): 26 control subjects who had never smoked or had regular exposure to environmental tobacco smoke, 26 who had never smoked but had been exposed to environmental tobacco smoke for at least one hour daily for three or more years, and 26 active smokers. Using ultrasonography, we measured the brachial-artery diameter under base-line conditions, during reactive hyperemia (with flow increase causing endothelium-dependent dilatation), and after sublingual administration of nitroglycerin (an endothelium-independent dilator).

RESULTS

Flow-mediated dilatation was observed in all control subjects (8.2 +/- 3.1 percent; range, 2.1 to 16.7) but was significantly impaired in the passive smokers (3.1 +/- 2.7 percent; range, 0 to 9; P < 0.001 for the comparison with the controls) and in the active smokers (4.4 +/- 3.1 percent; range, 0 to 10; P < 0.001 for the comparison with the controls; P = 0.48 for the comparison with the passive smokers). In the passive smokers, there was an inverse relation between the intensity of exposure to tobacco smoke and flow-mediated dilatation (r = -0.67, P < 0.001). In contrast, dilatation induced by nitroglycerin was similar in all groups.

CONCLUSIONS

Passive smoking is associated with dose-related impairment of endothelium-dependent dilatation in healthy young adults, suggesting early arterial damage.