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Biomedical subjects

L E Chambless

Publications and source records attributed to L E Chambless.

At least 37 records · Page 2Linked to original sources
PubMed2000

Trends in plasma cholesterol levels in the atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Data from the Atherosclerosis Risk in Communities (ARIC) cohort study were examined both cross-sectionally and intraindividually to confirm recent findings from population-based studies showing a decline in total cholesterol (TC) levels in the United States. METHODS: For the cross-sectional analysis, mean plasma TC levels from 15,792 participants aged 45-64 at baseline visit, and who were selected randomly from four U.S. communities, were examined for each year covered by the first cohort visit (1987, 1988, and 1989). Ninety-three percent of the cohort participants returned for the follow-up visit (1990, 1991, and 1992), and were included in the assessment of intraindividual TC trends. RESULTS: Both mean TC and prevalence of hypercholesterolemia (defined as plasma cholesterol concentration >/=240 mg/dl) consistently declined over the 3 years covered by visit 1 for all age-gender-race groups. For 1987, 1988, and 1989, mean TC values (mg/dl) were, respectively, 220.3, 216.7, and 214.1 (annual average change, -1.4%, P < 0.001). For these same years, hypercholesterolemia prevalence rates were 30. 0, 27.8, and 25.3% (annual average change, -7.8%, P < 0.001). The mean plasma TC also decreased within individuals between the two visits across race, gender, and age decade categories. With the exception of black men, this decline was more marked for older than younger subjects, but no consistent differences were seen between the racial groups. However, in whites, decreases were greater for men than for women. Expected results were seen when these changes were correlated with changes in cardiovascular risk factors between the two visits. CONCLUSION: The current study results are consistent with those of previous studies, and confirm the notion that preventive programs appear to be effective in reducing mean population TC levels.

Arteriosclerosis↗
PubMed2000

Trends in severity of hospitalized myocardial infarction: the atherosclerosis risk in communities (ARIC) study, 1987-1994.

BACKGROUND: Declining mortality rates of coronary heart disease in the United States could be attributable to declining incidence, declining severity, and/or improvements in treatment. METHODS: We examined trends in severity of patients hospitalized for myocardial infarction to characterize its contribution to this decline by using data from the Atherosclerosis Risk in Communities (ARIC) study. RESULTS: No significant change in the proportion having systolic blood pressure <100 mm Hg or an abnormal pulse at presentation was noted. The proportion with ST-segment elevation on the initial electrocardiogram increased 10% per year (P <.001), and the proportion with a diagnostic or evolving diagnostic electrocardiogram abnormality increased 4% per year (P <.01); the proportion that had a new Q-wave infarction develop remained unchanged. The mean peak creatine kinase level decreased 5% per year (P <.001), the proportion with abnormal enzyme levels decreased 10% per year (P <.001), and the proportion that met criteria for definite myocardial infarction decreased 4% per year (P <.05). The proportion that had cardiogenic shock decreased 10.9% per year (P <. 01), but the proportion that had an acute episode of congestive heart failure was stable. CONCLUSIONS: With stable hemodynamic indicators, worsening electrocardiographic indicators, and improving enzymatic indicators, these results provide mixed support for decreases in the severity of myocardial infarction.

Adult↗
PubMed2000

Glutathione S-transferase genotype as a susceptibility factor in smoking-related coronary heart disease.

Cancer studies suggest that the null polymorphisms of glutathione S-transferase M1 or T1 (GSTM1/GSTT1) may affect the ability to detoxify or activate chemicals in cigarette smoke. The potential modification of the association between smoking and coronary heart disease (CHD) by GSTM1 and GSTT1 has not been studied in humans. A case-cohort study was conducted to test the hypotheses that specific genotypes of GSTM1 or GSTT1 affect susceptibility to smoking-related CHD. CHD cases (n=400) accrued during 1987-1993 and a cohort-representative sample (n=924) were selected from a biracial cohort of 15792 middle-aged men and women in four US communities. A significantly higher frequency of GSTM1-0 and a lower frequency of GSTT1-0 were found in whites (GSTM1-0=47.1%, GSTT1-0=16.4%) than in African-Americans (AAs) (GSTM1-0=17.5%, GSTT1-0=25.9%). A smoking-GSTM1-0 interaction for the risk of CHD was statistically significant on an additive scale, with ever-smokers with GSTM1-0 at a approximately 1.5-fold higher risk relative to ever-smokers with GSTM1-1 and a approximately 2-fold higher risk relative to never-smokers with GSTM1-0, after adjustment for other CHD risk factors. The interaction between having smoked >/=20 pack-years and GSTT1-1 was statistically significant on both multiplicative and additive scales. The risk of CHD given both GSTT1-1 and >/=20 pack-years of smoking was approximately three times greater than the risk given exposure to >/=20 pack-years of smoking alone, and approximately four times greater than the risk given exposure to GSTT1-1 alone. The modification of the smoking-CHD association by GSTM1 or GSTT1 suggests that chemicals in cigarette smoke that are substrates for glutathione S-transferases may be involved in the etiology of CHD.

Case-Control Studies↗
PubMed2000

Fibrinogen, other putative markers of inflammation, and weight gain in middle-aged adults--the ARIC study. Atherosclerosis Risk in Communities.

PURPOSE: Weight gain is an important risk factor for the development of the metabolic syndrome, and inflammatory mediators are strongly associated with this syndrome. Our aim was to investigate whether inflammation predicts the development of weight gain in populations. RESEARCH METHODS AND PROCEDURES: We investigated selected markers of inflammation in the prediction of weight gain over an approximately 3-year period in a biethnic cohort of 13,017 men and women, 45 to 64 years of age, using multiple linear and logistic regression modeling. RESULTS: In adjusted models, those in the highest quartile of fibrinogen gained, during the first 3 years of follow-up, an estimated 0.23 kg/year more than those in the lowest quartile (p < 0.001). Adjusted odds of a large (greater than the 90th percentile) weight gain for those in the highest quartile of fibrinogen were 1.65 (95% confidence interval [CI], 1.38 to 1.97) times those in the lowest quartile. Similarly adjusted odds ratios for a large weight gain for those with high levels of white blood cell count, factor VIII, and von Willebrand factor were 1.38 (1.14 to 1.67), 1.28 (1.08 to 1.53), and 1.28 (1.08 to 1.51), respectively. DISCUSSION: Fibrinogen and other putative markers of inflammation predict weight gain in middle-aged adults. Given the known links between the inflammatory response and intermediary metabolism and the methodological strengths of the Atherosclerosis Risk in Communities (ARIC) cohort, these findings, though without immediate clinical applicability, suggest that inflammatory processes play a role in the development of the metabolic syndrome and cardiovascular disease in part through stimulation of weight gain.

Arteriosclerosis↗
PubMed2000

Determinants of population changes in fibrinogen and factor VII over 6 years: the Atherosclerosis Risk in Communities (ARIC) Study.

Although numerous cross-sectional studies have identified possible determinants of plasma fibrinogen and factor VII levels, few prospective studies exist. We assessed the longitudinal relation of changes in fibrinogen and factor VII over 6 years with changes to other cardiovascular risk factors in a sample of 440 men and 549 women from the Atherosclerosis Risk in Communities (ARIC) study. Fibrinogen increased more in older participants, those with or who developed diabetes, those who at any time smoked, and those whose plasma HDL cholesterol or triglycerides decreased and increased less in female participants who started hormonal replacement therapy. Factor VII coagulant activity increased more in younger participants, women, those who gained greater weight or developed diabetes, those who quit smoking, those in whom plasma triglycerides decreased, and female participants who received hormonal replacement therapy. Thus, our longitudinal data suggest with some exceptions that adverse changes in cardiovascular risk factors are accompanied by increases in plasma levels of fibrinogen and factor VII.

Aging↗
PubMed2000

Are retinal arteriolar abnormalities related to atherosclerosis?: The Atherosclerosis Risk in Communities Study.

The objective of this study was to describe associations of retinal arteriolar abnormalities with clinical and subclinical manifestations of atherosclerosis and a broad group of risk factors for vascular disease. A biracial population of 8772 adults (aged 48 to 72 years) living in 4 communities was examined from 1993 to 1995 were studied for that purpose. Retinal arteriovenous nicking and focal arteriolar narrowing were determined by light-box grading of a 45 degrees fundus photograph by use of a standardized protocol. Diameters of arterioles and venules were measured in digitized photographs, and a summary arteriolar-to-venular ratio was derived as an index of generalized arteriolar narrowing. Focal arteriolar narrowing was associated only with hypertension. Generalized arteriolar narrowing was associated with carotid plaque but not with any other evidence of atherosclerosis, either clinical (cardiovascular disease or stroke) or subclinical (carotid or popliteal artery thickness or lower limb obstructive disease), or with plasma cholesterol. It was also associated with smoking, with inflammatory markers (white blood cell count, fibrinogen, and reduced albumin), and with the triglyceride and high density lipoprotein cholesterol changes associated with inflammation. Arteriovenous nicking was inconsistently associated with subclinical atherosclerosis. It was not associated with cardiovascular disease, stroke, or plasma cholesterol. Arteriovenous nicking was associated with markers of inflammation and vascular endothelial dysfunction (von Willebrand factor and factor VIII). Arteriolar narrowing and nicking appear to be related to hypertension and inflammatory factors. Nicking may also be related to endothelial dysfunction. Results suggest that these arteriolar changes are pathologically distinct from atherosclerosis. Including their measurement in population studies may permit evaluation of the independent contribution of arteriolar disease to various ischemic diseases of the heart, brain, and other organs.

Aged↗
PubMed1999

Chlamydia pneumoniae infection and incident coronary heart disease: the Atherosclerosis Risk in Communities Study.

Pathologic findings and cross-sectional epidemiologic studies suggest that past infection with Chlamydia pneumoniae is associated with clinical and subclinical atherosclerotic disease, although evidence from prospective studies is still scarce. The association between chronic infection by C. pneumoniae and incident coronary heart disease (CHD) was investigated in a case-cohort study conducted among participants in the Atherosclerosis Risk in Communities Study who were free of CHD at the baseline examination (1986-1989). Levels of C. pneumoniae immunoglobulin G (IgG) antibodies in serum collected at baseline from 246 incident cases of CHD identified during follow-up (median, 3.3 years; maximum, 5 years) were compared with those from a stratified sample of the baseline cohort (n = 550). Among incident CHD cases, 65% had IgG antibody titers > or =1:64, compared with 55% of noncases (compared with negative IgG titers, the relative hazard of CHD was 1.6 (p < 0.01)). In multivariate analyses controlling for other risk factors (age, gender, smoking, serum cholesterol, hypertension, diabetes mellitus, and educational level), the above estimates were substantially reduced and became statistically nonsignificant (relative hazard = 1.2). A significantly increased CHD hazard associated with IgG antibody titers > or =1:64 was observed among nonsmokers, even after adjustment for other risk factors. Overall, these results do not provide strong support for the hypothesis that C. pneumoniae infection is a risk factor for clinical CHD. Studies with longer follow-up periods will be necessary to determine whether C. pneumoniae infection is involved as an etiologic factor in earlier phases of atherogenesis.

Antibodies, Bacterial↗
PubMed1999

Soluble thrombomodulin as a predictor of incident coronary heart disease and symptomless carotid artery atherosclerosis in the Atherosclerosis Risk in Communities (ARIC) Study: a case-cohort study.

BACKGROUND: Small amounts of soluble thrombomodulin in plasma are thought to reflect endothelial damage. In a case-cohort study, we examined whether soluble thrombomodulin is a predictor of incident coronary heart disease and carotid artery atherosclerosis. METHODS: The study population consisted of 14,170 black and white participants from the Atherosclerosis Risk in Communities (ARIC) study, who did not have cardiovascular disease at the start of the study and who we followed up for 6 years. After appropriate exclusions, we analysed 258 cases of incident coronary heart disease and 449 cases of carotid atherosclerosis. A stratified random sample of 753 individuals from the ARIC cohort was used as the comparison group. We used EIA to measure soluble thrombomodulin in plasma samples from both groups. For the analysis, we used quintiles of soluble thrombomodulin concentrations (< 24.7, 24.8-30.6, 30.7-40.2, 40.3-55.2, and > or = 55.3 ng/mL). FINDINGS: Soluble thrombomodulin showed a strong, graded, inverse association with incident coronary heart disease (p=0.005). The adjusted rate ratio of the highest quintile of soluble thrombomodulin compared with the lowest quintile was 0.29 (95% CI 0.15-0.57). The association with carotid atherosclerosis, however, tended to be positive, especially among white participants (odds ratio 2.94 [1.15-7.51] for highest vs lowest quintile). The relation of soluble thrombomodulin to incident coronary heart disease and carotid atherosclerosis was dependent on factor VIII coagulant activity (p=0.06 and 0.003, respectively). INTERPRETATION: The prospective association of soluble thrombomodulin with incident coronary heart disease differs from its cross-sectional association with carotid atherosclerosis. In healthy people, plasma concentrations of soluble thrombomodulin may reflect endothelial expression of thrombomodulin. High concentration of soluble thrombomodulin may be associated with decreased risk of coronary heart disease.

Analysis of Variance↗
PubMed1999

Relative importance of various risk factors for asymptomatic carotid atherosclerosis versus coronary heart disease incidence: the Atherosclerosis Risk in Communities Study.

Major risk factors for coronary heart disease are also associated with early carotid artery thickening, but no studies have yet examined patterns of risk factors to see whether they differ for the two outcomes. Assuming similar pathogenesis for both coronary and carotid atherosclerosis, one could interpret risk factor pattern differences as relating to differences in staging, i.e., early atheroma versus later stenotic or occlusive atherothrombosis. This study included 12,193 Atherosclerosis Risk in Communities Study participants aged 45-64 years who were free of clinical cardiovascular disease in 1987-1989, in whom 420 myocardial infarctions or coronary heart disease deaths occurred over the next 6 years. Plasma low density lipoprotein cholesterol, systolic blood pressure, and smoking were major risk factors for both outcomes. Compared with these factors, triglycerides and high density lipoprotein (HDL) cholesterol were associated only weakly with carotid atherosclerosis but were associated strongly with coronary heart disease incidence. No other risk factors, including those associated with diabetes mellitus, hemostasis, and inflammation, differed in their relative contribution to the two outcomes. These results suggest that the high triglyceride-low HDL cholesterol pattern is involved in the transition from atheroma to atherothrombosis, and that control of this pattern may be important in persons with detectable subclinical disease.

Arteriosclerosis↗
PubMed1999

Sex and race differences in short-term prognosis after acute coronary heart disease events: the Atherosclerosis Risk In Communities (ARIC) study.

BACKGROUND: Case fatality after myocardial infarction (MI) among patients admitted to the hospital may differ between men and women and blacks and whites. Furthermore, a different pattern of sex and race differences in case fatality may occur when coronary deaths outside the hospital are included in the analysis. The ARIC study provides community-based data to examine 28-day case fatality rates after coronary heart disease (CHD) events. METHOD AND RESULTS: Surveillance of out-of-hospital CHD deaths and hospitalized MI was conducted in 4 U.S. communities from 1987 to 1993. Hospital discharges and death certificates were sampled, medical records abstracted, and interviews conducted with witnesses of out-of-hospital deaths. MI and out-of-hospital death classifications followed a standard algorithm. Linkage of hospitalized MIs to fatality within 28 days ensured complete ascertainment of case fatality rate. Comorbidities and complications during hospital stay were compared to assess possible explanatory factors for differences in case fatality. Overall, age-adjusted 28-day case fatality (MI plus CHD) was higher in black men compared with white men (odds ratio 1.78, 95% confidence interval 1.4-2.2) and in black women compared with white women (odds ratio 1.5, 95% confidence interval 1. 2-2.0). Although men had higher overall case fatality rates than did women, this difference was not statistically significant. After a hospitalized MI, 28-day case fatality rate was not statistically significantly different between men compared with women or blacks compared with whites. CONCLUSION: Race and sex differences in case fatality after hospitalized MI were not evident in these data, although when out-of-hospital deaths were included, men and blacks were more likely than women and whites to die within 28 days of an acute cardiac event. A majority of deaths occurred before hospital admission, and additional study of possible reasons for these differences should be a priority.

Adult↗
PubMed1999

Variability in ultrasonic measurements of arterial stiffness in the Atherosclerosis Risk in Communities study.

Arterial stiffness is emerging as an important risk marker for cardiovascular disease. Ultrasound-based measurements of arterial stiffness are in use by several large epidemiological studies. The reliability of ultrasonic measurements of arterial stiffness was assessed as part of one of these, the Atherosclerosis Risk in Communities (ARIC) study. ARIC, a prospective, four-center epidemiological study, used B-mode ultrasound with an electronic tracking device to measure arterial stiffness of the carotid artery. Oscillometric blood pressure measures were obtained before and after the arterial wall tracking. Measurement variability was estimated in 36 volunteers who were scanned at three visits conducted at 7- to 14-day intervals. Between- and within-person components of variation were estimated for arterial diameter and blood-pressure measurements. The correlation (R) between repeated measurements for pulse pressure, the percent change in arterial diameter (strain), and the percent and absolute change in the arterial area were 0.69, 0.67, 0.66 and 0.81, respectively. The R for the stress-strain elastic modulus (Ep), arterial distensibility, and arterial compliance were 0.66, 0.67, and 0.77, respectively. The R for the pressure-adjusted diameter change (i.e., diameter change adjusted for diastolic and pulse pressures) was 0.75. In summary, the ultrasonic measurements of arterial stiffness employed in the ARIC study demonstrate excellent short-term repeatability, demonstrating their utility in field settings.

Arteriosclerosis↗
PubMed1999

Elevated fasting insulin predicts incident hypertension: the ARIC study. Atherosclerosis Risk in Communities Study Investigators.

OBJECTIVE: The prospective association of insulin and hypertension has been under debate in the context of the development of the insulin resistance or multiple metabolic syndrome. We examined the predictive associations of fasting serum insulin with incident hypertension occurring alone or as part of the multiple metabolic syndrome. DESIGN: Analyses were restricted to 5221 middle-aged participants of the Atherosclerosis Risk in Communities Study cohort who were free of component disorders of the multiple metabolic syndrome (hypertension; diabetes; high triglycerides and/or low HDL cholesterol (dyslipidaemias)) at baseline. OUTCOME: A total of 1018 individuals developed hypertension, 801 in the absence of components of the metabolic syndrome and 217 in combination with diabetes or dyslipidaemias, between 1987 and 1993. RESULTS: Elevated fasting insulin (top quartile versus lowest quartile) was associated with overall incident hypertension in European Americans [hazard rate ratio (HRR) 2.0, 95% confidence interval (CI) 1.7-2.4] but the results were inconclusive in African Americans (HRR 1.3, 95% CI 0.9-1.8) after adjustment for age, gender and study centre. Among European Americans, body mass index and abdominal girth only partly explained the observed association. Elevated fasting insulin was more strongly predictive of hypertension occurring as a component of the multiple metabolic syndrome (HRR 2.4, 95% CI 1.5-3.9) than of hypertension occurring alone (HRR 1.3, 95% CI 1.0-1.7) adjusting statistically for age, gender, study centre, body mass index and abdominal girth. CONCLUSIONS: The results are consistent with the concept of an aetiological heterogeneity for hypertension and may explain previously reported inconsistent findings on the association of insulin with incident hypertension.

Black or African American↗
PubMed1999

Descriptive epidemiology of blood pressure response to change in body position. The ARIC study.

The epidemiology of a common measure of cardiovascular reactivity, the change in systolic blood pressure (DeltaSBP) from the supine to the standing position, is described in a cohort of 13 340 men and women aged 45 to 65 years enrolled in the Atherosclerosis Risk in Communities (ARIC) Study. The distribution of DeltaSBP was found to be symmetrical and unimodal, with a mean value near zero (-0.45 mm Hg). The range of DeltaSBP was from -63.2 to 54.3 mm Hg, and the standard deviation was 10.8. Stratification of DeltaSBP by race and gender shows a slight shift in distribution toward higher values for black men and women. DeltaSBP was categorized into deciles. Participants in the top 30% and bottom 30% of the distribution were compared with individuals in the middle 40% of the distribution, who had little or no change in SBP on standing. Participants in the bottom 30% (ie, SBP decreased on standing) were significantly older, had a greater prevalence of hypertension and peripheral vascular disease, had higher values of SBP, and had more cigarette-years of smoking. Among participants in the top 30% (ie, SBP increased on standing), a significantly larger proportion were black, mean seated SBP was higher, and the predicted risk of developing coronary heart disease after 8 years was greater. The response of SBP to change in posture showed considerable variability in a population sample of middle-aged adults. Cardiovascular morbidity, sociodemographic factors, and cigarette smoking were associated with the magnitude and direction of the postural change.

Age Factors↗
PubMed1999

Arterial stiffness and the development of hypertension. The ARIC study.

Decreased elasticity in large and medium-sized arteries has been postulated to be associated with cardiovascular diseases. We prospectively examined the relation between arterial elasticity and the development of hypertension over 6 years of follow-up in a cohort of 6992 normotensive men and women aged 45 to 64 years at baseline from the biracial, population-based Atherosclerosis Risk in Communities (ARIC) Study. Arterial elasticity was measured from high-resolution B-mode ultrasound examination of the left common carotid artery as adjusted arterial diameter change (in micrometers, simultaneously adjusted for diastolic blood pressure, pulse pressure, pulse pressure squared, diastolic arterial diameter, and height), Peterson's elastic modulus (in kilopascals), Young's elastic modulus (in kilopascals), and beta stiffness index. Incident hypertension (n=551) was defined as systolic blood pressure >/=160 mm Hg, diastolic blood pressure >/=95 mm Hg, or the use of antihypertensive medication at a follow-up examination conducted every 3 years. The age-, ethnicity-, center-, gender-, education-, smoking-, heart rate-, and obesity-adjusted means (SE) of baseline adjusted arterial diameter change, Peterson's elastic modulus, Young's elastic modulus, and beta stiffness index were 397 (5), 148 (2.0), 787 (12.7), and 11.43 (0.16), respectively, in persons who developed hypertension during follow-up, in contrast to 407 (1), 124 (0.6), 681 (3.7), and 10.34 (0.05), respectively, for persons who did not. The similarly adjusted cumulative incident rates of hypertension from the highest to the lowest quartiles of arterial elasticity were 6.7%, 8.0%, 7.3%, and 9.6%, respectively, when measured by adjusted arterial diameter change (P<0.01). One standard deviation decrease in arterial elasticity was associated with 15% greater risk of hypertension, independent of established risk factors for hypertension and the level of baseline blood pressure. These results suggest that lower arterial elasticity is related to the development of hypertension.

Age Factors↗
PubMed1999

Stroke incidence and survival among middle-aged adults: 9-year follow-up of the Atherosclerosis Risk in Communities (ARIC) cohort.

BACKGROUND AND PURPOSE: Although stroke mortality rates in the United States are well documented, assessment of incidence rates and case fatality are less well studied. METHODS: A cohort of 15 792 men and women aged 45 to 64 years from a population sample of households in 4 US communities was followed from 1987 to 1995, an average of 7. 2 years. Incident strokes were identified through annual phone contacts and hospital record searching and were then validated. RESULTS: Of the 267 incident definite or probable strokes, 83% (n=221) were categorized as ischemic strokes, 10% (n=27) were intracerebral hemorrhages, and 7% (n=19) were subarachnoid hemorrhages. The age-adjusted incidence rate (per 1000 person-years) of total strokes was highest among black men (4.44), followed by black women (3.10), white men (1.78), and white women (1.24). The black versus white age-adjusted rate ratio (RR) for ischemic stroke was 2.41 (95% CI, 1.85 to 3.15), which was attenuated to 1.38 (95% CI, 1.01 to 1.89) after adjustment for baseline hypertension, diabetes, education level, smoking status, and prevalent coronary heart disease. There was a tendency for the adjusted case fatality rates to be higher among blacks and men, although none of the case fatality comparisons across sex or race was statistically significant. CONCLUSIONS: After accounting for established baseline risk factors, blacks still had a 38% greater risk of incident ischemic stroke compared with whites. Identification of new individual and community-level risk factors accounting for the elevated incidence of stroke requires further investigation and incorporation into intervention planning.

Age Distribution↗
PubMed1999

Lower pulmonary function and cerebral subclinical abnormalities detected by MRI: the Atherosclerosis Risk in Communities study.

STUDY OBJECTIVES: To investigate the association between pulmonary function and (1) cerebral infarction and (2) white matter lesions (WMLs), identified by MRI and believed to represent subclinical lesions of arteriosclerosis, generalized hypoperfusion, or ischemia of the brain. DESIGN: Population-based, cross-sectional study. SETTING: Two communities in the United States. PARTICIPANTS: A sample of 1,917 African-American and white men and women 55 to 72 years old who were selected from the second follow-up examination of the Atherosclerosis Risk in Communities Study cohort. INTERVENTIONS: Observational study. MEASUREMENTS AND RESULTS: The lung function indexes, FEV1 and FVC, were assessed according to American Thoracic Society criteria. Subclinical cerebral infarction and WMLs were assessed by MRI. After adjusting for age, ethnicity, gender, height, and height squared, a 1-SD decrease of FEV1 in nonsmokers was associated with odds ratios (95% confidence interval [CI], 1.31 to 2.03) of 1.63 for infarction and 1.35 (95% CI, 1.08 to 1.69) for WMLs. Of those in the lowest quartile of FEV1, 15% had infarction and WMLs, in contrast to 6% of the individuals in the uppermost quartile of FEV1. Consistent associations were also observed by using FVC as an index of pulmonary function. Similar patterns of association were found among current smokers. The associations were not altered by additional adjustment of conventional risk factors of cardiovascular disease, comorbidity, or cognitive function. CONCLUSION: The results from this population-based study suggest that lower pulmonary function is associated with subclinical cerebral abnormalities.

Brain↗
PubMed1999

Prospective associations of fasting insulin, body fat distribution, and diabetes with risk of ischemic stroke. The Atherosclerosis Risk in Communities (ARIC) Study Investigators.

OBJECTIVE: We tested the hypothesis that diabetes, body fat distribution, and (in nondiabetic subjects) fasting insulin levels are positively associated with ischemic stroke incidence in the general population. RESEARCH DESIGN AND METHODS: As part of the Atherosclerosis Risk in Communities (ARIC) Study, we measured diabetes by using fasting glucose criteria, waist and hip circumferences, and fasting insulin levels with a radioimmunoassay in > 12,000 adults aged 45-64 years who had no cardiovascular disease at baseline. We followed them for 6-8 years for ischemic stroke occurrence (n = 191). RESULTS: After adjustment for age, sex, race, ARIC community, smoking, and education level, the relative risk of ischemic stroke was 3.70 (95% CI 2.7-5.1) for diabetes, 1.74 (1.4-2.2) for a 0.11 increment of waist-to-hip ratio, and 1.19 (1.1-1.3) for a 50-pmol/l increment of fasting insulin among nondiabetic subjects. Ischemic stroke incidence was not statistically significantly associated with BMI (comparably adjusted relative risk = 1.15, 95% CI 0.97-1.36). With adjustment for other stroke risk factors (some of which may mediate the effects of diabetes, fat distribution, and hyperinsulinemia), the relative risks for diabetes, waist-to-hip ratio, and fasting insulin level were 2.22 (95% CI 1.5-3.2), 1.08 (0.8-1.4), and 1.14 (1.01-1.3), respectively. CONCLUSIONS: Diabetes is a strong risk factor for ischemic stroke. Aspects of insulin resistance, as reflected by elevated waist-to-hip ratios and elevated fasting insulin levels, may also contribute to a greater risk of ischemic stroke.

Adipose Tissue↗