Biomedical subjects

Lloyd E Chambless

Publications and source records attributed to Lloyd E Chambless.

40 records · Page 3Linked to original sources

PubMed2002

LPL polymorphism predicts stroke risk in men.

Variation in lipid levels has been associated with atherosclerotic vascular disease, including stroke. Genes contributing to interindividual variation in lipid levels may play a role in the etiology of stroke, either through their effects on lipid synthesis and metabolism or through separate pathways. For this reason, we sought to examine the association between polymorphisms in the lipoprotein lipase (LPL) and apolipoprotein E (APOE) genes and subclinical and clinical stroke in the Atherosclerosis Risk in Communities (ARIC) Study. Subclinical stroke was determined by cerebral magnetic resonance imaging (MRI). Subclinical cerebral infarct cases (n = 197) were compared to a stratified random sample identified from individuals participating in the MRI examination (n = 200). Incidence of clinical ischemic stroke was determined by following the ARIC cohort for an average of 7.5 years for potential cerebrovascular events; 218 validated clinical ischemic strokes were identified. A stratified random sample of the ARIC cohort (CRS, n = 964) was used as the comparison group for clinical cases. The LPL S291-carrying genotypes and APOE epsilon2- and epsilon4-carrying genotypes were not significantly associated with subclinical or clinical stroke. The LPL X447-containing genotypes were significantly associated with subclinical (odds ratio [OR], 4.32; 95% confidence interval [CI], 1.23-15.15; P = 0.020) and clinical stroke (hazard rate ratio [HRR], 2.57; 95% CI, 1.24-5.34; P = 0.01) in men, both by themselves and after adjustment for multiple stroke risk factors. The LPL S447X polymorphism is significantly associated with subclinical cerebral infarction and incident clinical ischemic stroke in men from a middle-aged American population. This association does not appear to be mediated by triglyceride, high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol levels, or additional stroke risk factors.

Apolipoproteins E↗

PubMed2002

Correlates of the shift in heart rate variability with an active postural change in a healthy population sample: The Atherosclerosis Risk In Communities study.

BACKGROUND: The heart rate variability (HRV) response to postural change is a sensitive measure of the shift in autonomic balance from parasympathetic to sympathetic predominance that, when attenuated or absent, has been correlated with prevalent disease in patient populations. In a healthy population sample, we evaluated whether the shift in HRV with postural change differed by demographic characteristics as well as whether it differed between participants with established coronary heart disease (CHD) risk factors and their counterparts. METHODS: HRV was measured for 2 minutes in the supine and standing positions in a biracial sample of men and women (aged 45-64 years) without clinical CHD from the Atherosclerosis Risk In Communities Study (n = 7686). Mean differences among supine and standing mean R-R interval lengths, the SD of R-R intervals, and high-frequency power (HF) were compared by demographic characteristics (age, race, and sex) and CHD risk factors (smoking, obesity, physical activity, hypertension, and diabetes). Multivariable linear regression models were used to adjust for demographic characteristics. RESULTS: Smaller changes in R-R intervals and larger changes in SD of R-R intervals with standing were found among participants who were obese, less physically active than their counterparts, hypertensive, and diabetic. Smaller changes in HF were identified in male and white participants, but there were no differences in HF by CHD risk factors once models were adjusted for demographic characteristics. CONCLUSIONS: These simple noninvasive measures can be used to detect differences in cardiac autonomic balance that may be markers for autonomic impairment in healthy adults.

Age Factors↗

PubMedDate not supplied

Risk factors for coronary heart disease in African Americans: the atherosclerosis risk in communities study, 1987-1997.

BACKGROUND: As part of the Atherosclerosis Risk in Communities Study, the race-specific incidence rates and risk factor prediction for coronary heart disease (CHD) were determined for black and white persons over 7 to 10 years of follow-up, from 1987 to 1997. METHODS: The sample included 14 062 men and women (2298 black women, 5686 white women, 1396 black men, and 4682 white men) aged 45 to 64 years who were free of clinical CHD at baseline. RESULTS: Average age-adjusted incidence rates (95% confidence intervals) for CHD per 1000 person-years were as follows: black women, 5.1 (4.2-6.2); white women, 4.0 (3.5-4.6); black men, 10.6 (8.9-12.7); and white men, 12.5 (11.5-13.7). Incidence rates (95% confidence intervals) using a definition for CHD that excluded revascularization procedures were as follows: black women, 4.9 (4.6-6.0); white women, 2.9 (2.5-3.4); black men, 9.2 (7.6-11.1); and white men, 7.9 (7.0-8.8). In a multivariable analysis, hypertension was a particularly strong risk factor in black women, with hazard rate ratios (95% confidence intervals) as follows: black women, 4.8 (2.5-9.0); white women, 2.1 (1.6-2.9); black men, 2.0 (1.3-3.0); and white men, 1.6 (1.3-1.9). Diabetes mellitus was somewhat more predictive in white women than in other groups. Hazard rate ratios (95% confidence intervals) were as follows: black women, 1.8 (1.2-2.8); white women, 3.3 (2.4-4.6); black men, 1.6 (1.1-2.5); and white men, 2.0 (1.6-2.6). Low-density lipoprotein cholesterol level was similarly predictive in all race-sex groups (hazard rate ratio, 1.2-1.4 per SD increment of low-density lipoprotein cholesterol level). High-density lipoprotein cholesterol level seemed somewhat more protective in white than in black persons. CONCLUSIONS: Findings from this study, along with clinical trial evidence showing efficacy, support aggressive management of traditional risk factors in black persons, as in white persons. Understanding the intriguing racial differences in risk factor prediction may be an important part of further elucidating the causes of CHD and may lead to better methods of preventing and treating CHD.

Age Distribution↗

PubMedDate not supplied

Association between symptoms reported in a population questionnaire and future ischemic stroke: the ARIC study.

The association between computer diagnosis derived from a symptom questionnaire and onset of first hospitalized ischemic stroke during follow-up for up to 11 years has been assessed for 11,804 participants in the Atherosclerosis Risk in Communities Study who had no baseline history of stroke. Of these participants, 578 reported prior positive transient ischemic attack/stroke symptoms, and 265 strokes occurred during the years 1987-1998. Adjusted for age, locale, sex, and race, persons with self-reported baseline symptoms had 2.8 times the hazard rate for incident ischemic stroke of those without symptoms, with 95% confidence interval 1.9-4.1. Greater relative risk was found among younger individuals, women, African-Americans, persons not current smokers, and those with lower white blood cell count.

Algorithms↗