Biomedical subjects

L E Wagenknecht

Publications and source records attributed to L E Wagenknecht.

At least 19 recordsLinked to original sources

PubMed2006

Genetic mapping of a 17q chromosomal region linked to obesity phenotypes in the IRAS family study.

OBJECTIVE: Obesity is widely accepted to be influenced by both environmental and genetic factors. Several recent studies have used the positional cloning approach in an attempt to discover genes contributing to obesity. In the IRAS Family Study a genomewide scan was performed on 1425 individuals of Hispanic descent (90 extended pedigree families) to identify regions of the genome linked to obesity phenotypes. METHODS: Nonparametric QTL linkage analysis was performed using a variance components approach. The genome scan was performed in two phases: an initial genome scan in 45 families and a replication scan in 45 families. Fine mapping and candidate gene analyses were also performed. General estimating equations (GEE1) and quantitative pedigree disequilibrium tests (QPDT) were used for association analysis of single SNP and haplotype data. RESULTS: Evidence for linkage to obesity traits was observed in each scan on the long arm of chromosome 17. When data from both scans was combined, a region on chromosome 17q was identified with evidence of linkage to visceral adipose tissue (VAT; LOD 3.11), waist circumference (WAIST) (LOD 2.5) and body mass index (BMI) (LOD 2.81). Nine additional microsatellite markers were identified and genotyped on all Hispanic individuals, with a mean marker density of approximately 1 marker/3 cM. Evidence of linkage remained significant with LOD 3.05 for VAT, LOD 2.44 for BMI and LOD 1.92 for WAIST. Fine mapping analyses suggest the possibility of two different obesity loci. In addition, the LOD - 1 interval of the major VAT peak decreased from 83-108 to 95-111 cM. Three positional candidate genes under the peak: somatostatin receptor 2 (SSTR2), galanin receptor 2 (GALR2), and growth hormone bound protein receptor 2 (GRB2) were chosen for detailed evaluation. Multiple polymorphisms within each candidate were genotyped and tested for association with the obesity phenotypes. Little evidence of association was detected between polymorphisms and obesity traits. CONCLUSION: In conclusion, replication of linkage and fine mapping suggest that a region on chromosome 17q contains a gene (or genes) that contributes to the genetic etiology of obesity with the strongest evidence for linkage to VAT. Candidate genes in the region do not appear to account for the evidence of linkage. Additional studies are necessary to identify the obesity-related polymorphisms.

Adult↗

PubMed2006

Association analysis of genes in the renin-angiotensin system with subclinical cardiovascular disease in families with Type 2 diabetes mellitus: the Diabetes Heart Study.

AIMS: Cardiovascular disease (CVD) is a major complication of Type 2 diabetes mellitus. The renin-angiotensin system (RAS) and nitric oxide production are both important regulators of vascular function and blood pressure. Genes encoding proteins involved in these pathways are candidates for a contribution to CVD in diabetic patients. We have investigated variants of the angiotensinogen (AGT), angiotensin converting enzyme (ACE), angiotensin type 1 receptor (AT1R) and endothelial nitric oxide synthase (NOS3) genes for association with subclinical measures of CVD in families with Type 2 diabetes mellitus (T2DM). METHODS: Atherosclerosis was measured by carotid intima-media thickness and calcification of the carotid and coronary arteries in 620 European Americans and 117 African Americans in the Diabetes Heart Study. Because of the role of these systems in blood pressure regulation, blood pressure was also investigated. RESULTS: Compelling evidence of association was not detected with any of the SNPs with any outcome measures after adjustments for covariates despite sufficient power to detect relatively small differences in traits for specific genotype combinations. CONCLUSIONS: Genetic variation of the RAS and NOS3 genes do not appear to strongly influence subclinical cardiovascular disease or blood pressure in this diabetic population.

Adult↗

PubMed2006

Cross-sectional correlates of fasting hyperinsulinaemia in post-menopausal women of different ethnic origin.

AIMS: In a large ethnically diverse nationwide sample of post-menopausal women we explored the relationship between fasting insulin levels, ethnicity, and a wide range of anthropometric, socio-economic, and lifestyle factors. METHODS: Subjects were post-menopausal women aged 50-79 years without diagnosed diabetes mellitus comprising a subsample (n = 3500) of the Women's Health Initiative (WHI) Clinical Trial and Observational Study. In a cross-sectional survey at baseline, we analysed the association between ethnicity and fasting insulin using analysis of covariance procedures and identified independent correlates of hyperinsulinaemia, defined by the 75th percentile cut point for each ethnic group. RESULTS: Fasting insulin levels were higher among African-American and Hispanic women than among non-Hispanic White or Asian women. These differences persisted after adjustment for age, educational attainment, total and central body obesity, adult weight change, family history of diabetes, smoking status, alcohol consumption, use of menopausal hormone therapy and physical activity. Higher levels of body mass index, waist-hip ratio, adult weight gain, and lower levels of total and moderate or strenuous recreational activity were independent correlates of fasting hyperinsulinaemia. Habitual walking was also inversely associated with fasting insulin. CONCLUSIONS: In this cross-sectional analysis, fasting insulin levels were higher among African-American and Hispanic post-menopausal women as compared with non-Hispanic White and Asian women. In addition, obesity, adult weight gain, and low levels of moderate or strenuous physical activity were independently associated with hyperinsulinaemia.

Black or African American↗

PubMed2006

Hormone replacement therapy is associated with increased C-reactive protein in women with Type 2 diabetes in the Diabetes Heart Study.

AIMS: Increased levels of inflammatory biomarkers, especially C-reactive protein (CRP), are associated with increased risk for cardiovascular disease (CVD) events, such as myocardial infarction, stroke, peripheral vascular disease, and sudden cardiac death. Medical interventions that increase CRP levels, such as hormone replacement therapy (HRT) in post-menopausal women, are under increasing scrutiny. The effect of HRT on CRP levels in women with Type 2 diabetes (T2DM) is not well documented, and conflicting conclusions have been reported. The aim of this study was to determine the influence of HRT on women with diabetes in a large cross-sectional study. METHODS: Three hundred and twenty-seven post-menopausal women with T2DM from the Diabetes Heart Study participated. Current use of HRT was determined and serum CRP levels were measured using a high-sensitivity ELISA kit. Generalized estimating equation methods were used to assess the relationship of multiple clinical and lifestyle (e.g. smoking) measures on CRP levels including differences between women taking HRT (HRT+) and not taking HRT (HRT-). RESULTS: Overall serum CRP levels were strongly associated with body mass index (P < 0.0001) and age (P < 0.0001). Of the women, 243 were not using HRT and 84 were using HRT. HRT+ and HRT- women did not differ significantly in measures of clinical traits, with the exception of higher mean low-density lipoprotein cholesterol in HRT- women (P = 0.004). In all models tested, HRT+ women had significantly higher circulating CRP levels, with P-values ranging from 0.0045 to 0.010. CONCLUSIONS: In this study of serum CRP concentration as a function of HRT in women with Type 2 diabetes, there was consistent evidence for increased circulating CRP levels in women receiving oestrogen-containing HRT. Whether HRT-induced increases in CRP can account for the adverse cardiovascular effects of HRT remains to be established; however, based on these data, there is little reason to believe that diabetic women would be spared from such an effect.

Body Mass Index↗

PubMed2005

The impact of ethnicity and sex on subclinical cardiovascular disease: the Diabetes Heart Study.

AIMS/HYPOTHESIS: African-Americans with type 2 diabetes and access to adequate healthcare are at lower risk of clinical coronary artery disease than are white diabetic patients. We evaluated whether ethnic differences in subclinical cardiovascular disease, coronary and carotid artery calcified plaque and carotid artery intima-medial thickness (IMT) were present in members of The Diabetes Heart Study families. SUBJECTS AND METHODS: In a bi-racial cohort of 1,180 individuals from families enriched for members with type 2 diabetes, we calculated coronary and carotid artery calcified plaque using fast-gated helical computed tomography, and measured carotid artery IMT and clinical risk factor profiles. Generalised estimating equations were used to test for an association between measures of subclinical cardiovascular disease and ethnicity and sex. RESULTS: After adjustment for age, ethnicity and kidney function, African-Americans had significantly lower amounts of coronary artery calcified plaque (mean+/-SE) (866+/-158 vs 1,915+/-135, respectively; p=0.0466) and carotid artery calcified plaque (179+/-51 vs 355+/-27, respectively; p=0.0240) relative to whites, despite having increased carotid IMT (0.71+/-0.01 vs 0.67+/-0.004 cm, respectively; p=0.0007), and higher blood pressure, albuminuria and HbA1c. Sex-specific analyses revealed that African-American men had significantly lower coronary and carotid artery calcified atheroma than white men. In women, ethnic differences in calcified carotid artery plaque, but not coronary artery plaque, were observed. CONCLUSIONS/INTERPRETATION: In families enriched for members with type 2 diabetes, African-American men had markedly lower levels of coronary and carotid artery calcified plaque than white men, despite increased carotid artery IMT and conventional risk factors. These findings suggest that susceptibility to subclinical cardiovascular disease differs markedly according to ethnicity and sex.

Adult↗

PubMed2005

Quantitative trait loci for abdominal fat and BMI in Hispanic-Americans and African-Americans: the IRAS Family study.

OBJECTIVE: To conduct linkage analysis for body mass index (BMI, kg/m2), waist-to-hip ratio (WHR), visceral adipose tissue mass (VAT, cm2) and subcutaneous adipose tissue mass (SAT, cm2) using a whole genome scan. DESIGN: Cross-sectional family study. STUDY SUBJECTS: African-American families from Los Angeles (AA, n=21 extended pedigrees) and Hispanic-American families (HA) from San Antonio, TX (HA-SA, n=33 extended pedigrees) and San Luis Valley, CO (HA-SLV, n=12 extended pedigrees), totaling 1049 individuals in the Insulin Resistance and Atherosclerosis (IRAS) Family Study. MEASUREMENTS: VAT and SAT were measured using a computed tomography scan obtained at the fourth and fifth lumbar vertebrae. All phenotypes were adjusted for age, gender, and study center. VAT, SAT, and WHR were analyzed both unadjusted and adjusted for BMI. RESULTS: Significant linkage to BMI was found at D3S2387 (LOD=3.67) in African-Americans, and at D17S1290 in Hispanic-Americans (LOD=2.76). BMI-adjusted WHR was linked to 12q13-21 (D12S297 (LOD=2.67) and D12S1052 (LOD=2.60)) in Hispanic-Americans. The peak LOD score for BMI-adjusted VAT was found at D11S2006 (2.36) in Hispanic families from San Antonio. BMI-adjusted SAT was linked to D5S820 in Hispanic families (LOD=2.64). Evidence supporting linkage of WHR at D11S2006, VAT at D17S1290, and SAT at D1S1609, D3S2387, and D6S1056 was dependent on BMI, such that the LOD scores became nonsignificant after adjustment of these phenotypes for BMI. CONCLUSIONS: Our findings both replicate previous linkage regions and suggest novel regions in the genome that may harbor quantitative trait locis contributing to variation in measures of adiposity.

Adipose Tissue↗

PubMed2005

Association of adipose tissue deposition and beta-2 adrenergic receptor variants: the IRAS family study.

OBJECTIVE: Adipose tissue distribution (visceral vs subcutaneous) has been shown to be an important predictor of insulin resistance, diabetes and cardiovascular disease, independent of body mass index. The beta-2 adrenergic receptor is a major lipolytic receptor in human fat cells and the gene that codes for this protein is an important candidate gene for measures of adiposity and fat deposition. We examined whether two common polymorphisms in codons 16 (Arg16Gly) and 27 (Gln27Glu) are associated with measures of fat distribution in participants of the IRAS Family Study. METHODS: We recruited African-American (AA) and Hispanic-American (HA) families from Los Angeles, CA, USA (18 pedigrees, 272 AA individuals), San Antonio, TX, USA (33 pedigrees, 448 HA individuals) and San Luis Valley, CO, USA (12 pedigrees, 272 HA individuals). We estimated adipose tissue distribution via computed tomography. To test for an association between adiposity measures and these polymorphisms, we used generalized estimating equations, adjusting for age, gender, clinical site (ethnicity), body mass index, and familial correlation. RESULTS: Of the 992 individuals genotyped for these polymorphisms, 57% were female and 15% had been diagnosed with type 2 diabetes mellitus. The mean age was 42.7+/-14.6 y. The Glu27 allele of the Gln27Glu polymorphism was positively associated with (P-value for recessive model): body mass index (0.025), visceral adipose tissue (<0.0001) and visceral-to-subcutaneous adipose ratio (0.009), but not with subcutaneous adipose tissue (0.952). The Arg16Gly polymorphism was not associated with any of the adiposity measures. CONCLUSIONS: These findings suggest that genetic variation in the beta-2 adrenergic receptor gene influences fat deposition and body size in AAs and HAs. In particular, these results support a role for the gene in the distribution of visceral adipose tissue but not subcutaneous adipose tissue.

Adipose Tissue↗

PubMed2005

Abdominal obesity predicts declining insulin sensitivity in non-obese normoglycaemics: the Insulin Resistance Atherosclerosis Study (IRAS).

AIM: Cross-sectional studies have demonstrated a relationship between obesity and insulin sensitivity (S(I)); however, there is a lack of evidence from longitudinal studies. METHODS: The Insulin Resistance Atherosclerosis Study (IRAS) estimated S(I) (x10(-4)/min.microU/ml) directly using a frequently sampled intravenous glucose tolerance test with minimal model analysis in 504 normoglycaemic subjects. Partial correlation coefficients (r) were calculated to compare the relationship of change in S(I) from baseline to 5 years later (DeltaS(I)) with baseline waist circumference (waist) as a measure of abdominal obesity and body mass index (BMI) as a measure of overall obesity. Mean DeltaS(I) was -1.06 (SD = 1.85). RESULTS: Higher baseline waist (r = -0.16; p = 0.0005), but not BMI (r = -0.005; p = 0.91), was associated with (-) DeltaS(I) in models including sex, ethnicity, clinical centre and baseline S(I), BMI, waist, age and physical activity. The waist-DeltaS(I) relationship differed across the levels of baseline BMI, being significant only in normal weight (r = -0.21) and overweight subjects (r = -0.16), but not in obese subjects. DeltaS(I) was correlated with a 5-year change in either obesity measure (Deltawaist: r = -0.22 and DeltaBMI: r = -0.20; p = 0.0001). CONCLUSIONS: Among non-diabetics, waist circumference was a strong predictor of declining S(I) among lean subjects, a modest predictor among overweight subjects, but was not predictive among obese individuals. Waist circumference should be considered, in addition to BMI, when identifying individuals at high risk of diabetes or the insulin resistance syndrome.

Abdomen↗

PubMed2005

Association of genes of lipid metabolism with measures of subclinical cardiovascular disease in the Diabetes Heart Study.

BACKGROUND: Dyslipidaemia is a well known risk factor for cardiovascular disease (CVD). Lipid metabolism is affected by a range of genes and proteins. This study investigated whether some of these genes are associated with measures of subclinical CVD. METHODS: Polymorphisms of paraoxonase 1 and 2, cholesteryl ester transfer protein, hepatic lipase, and lipoprotein lipase were tested for associations with measures of subclinical CVD including carotid intima-media thickness measured by B-mode ultrasound and carotid and coronary arterial calcification measured by computed tomography. Analysis was performed in 620 European American participants in the Diabetes Heart Study, 83% of whom had type 2 diabetes mellitus. Associations of genotypes with subclinical CVD were tested by computing a series of generalised estimating equations. RESULTS: The Q192R variant of paraoxonase 1 and rs285 of lipoprotein lipase were associated with carotid artery calcium (p values = 0.002 and 0.005, respectively). Paraoxonase 2 S311C was associated with coronary artery calcium (p value = 0.037). CONCLUSIONS: There is evidence for modest, but significant, association of multiple single nucleotide polymorphisms in lipid genes with measures of subclinical CVD.

Aged↗

PubMed2004

Insulin resistance and weight gain in postmenopausal women of diverse ethnic groups.

OBJECTIVE: This study was conducted to examine the influence of insulin resistance on weight change in postmenopausal women of various ethnic groups. SUBJECTS: Data were obtained from 3389 women (60% White, 20% Black, 12% Hispanic, and 8% Asian/Pacific Islander), ages 50-79, enrolled in either the Women's Health Initiative Clinical trial or Observational Study, whose blood samples were selected randomly from the full cohort of 161 809 women for analyses. MEASUREMENTS: Glucose, insulin, and lipids were measured on fasting serum samples drawn at baseline and after 3 y of follow-up. Weight, height, waist circumference, and blood pressure were measured. Physical activity and energy intake were assessed via questionnaire. Insulin resistance was estimated using the HOMA (homeostasis model) calculation. RESULTS: Average age was 62 y, average BMI (body mass index) was 27.4 kg/m2, and average weight change was a gain of 0.4 kg in 3 y. In a multivariate analysis, insulin resistance and insulin concentrations were independent predictors of increases in weight in White women (P=0.002 and 0.004, respectively) and in the combined group (P=0.027 and 0.039). For the whole group, after adjustment for other covariates, those in the highest quartile of insulin resistance gained 0.4 kg in 3 y, whereas those in the lowest quartile lost 0.06 kg. Similar trends were found for insulin resistance and weight gain in Hispanic and Asian/Pacific Islander women, but they did not reach statistical significance. In Black women, no relation was seen between either insulin or insulin resistance and weight change. A significant interaction between obesity and insulin resistance was observed (P=0.002 for White women and 0.032 for the whole group), so that there is weight gain with increasing insulin resistance in the leaner women, but weight loss with increasing insulin resistance in the most obese. CONCLUSION: Insulin resistance appears to be a predictor of weight gain in postmenopausal women, except for the most obese women. The effect is more pronounced in women who have a lower BMI, and the effect was not seen in the Black women who as a group had a higher BMI.

Blood Glucose↗

PubMed2001

Ten-year changes in smoking among young adults: are racial differences explained by socioeconomic factors in the CARDIA study?

OBJECTIVES: This study investigated whether socioeconomic factors explain racial/ethnic differences in regular smoking initiation and cessation. METHODS: Data were derived from the CARDIA study, a cohort of 5115 healthy adults aged 18 to 30 years at baseline (1985-1986) and recruited from the populations of 4 US cities. Respondents were followed over 10 years. RESULTS: Among 3950 respondents reexamined in 1995-1996, 20% of Whites and 33% of African Americans were smokers, as compared with 25% and 32%, respectively, in 1985-1986. On average, African Americans were of lower socioeconomic status. Ten-year regular smoking initiation rates for African American women, White women, African American men, and White men were 7.1%, 3.5%, 13.2%, and 5.1%, respectively, and the corresponding cessation rates were 25%, 35.1%, 19.2%, and 31.3%. After adjustment for socioeconomic factors, most 95% confidence intervals of the odds ratios for regular smoking initiation and cessation in African Americans vs Whites included 1. CONCLUSIONS: Less beneficial 10-year changes in smoking were observed in African Americans, but socioeconomic factors explained most of the racial disparity.

Adolescent↗

PubMed2001

Familial aggregation of coronary artery calcium in families with type 2 diabetes.

Type 2 diabetes is widely recognized as a major risk factor for atherosclerotic cardiovascular disease, including subclinical atherosclerosis as measured by noninvasive procedures. However, the role of genetic factors that contribute to various measures of subclinical atherosclerosis is largely unknown. We hypothesize that subclinical atherosclerosis, measured as coronary artery calcification (CAC), will be extensive in individuals with type 2 diabetes and that its presence depends on both genetic and environmental factors. The genetic factors should result in the familial aggregation of CAC. To determine the extent of familial aggregation of CAC in the presence of type 2 diabetes, we studied 122 individuals with type 2 diabetes (mean age 60 years) and 13 individuals without diabetes in 56 families. CAC was measured by fast-gated helical computed tomography. Other measured factors included blood pressure, body size, lipids, HbA1c, and self-reported medical history. To test for an association between CAC and these factors while accounting for the potential familial correlation of CAC, generalized estimating equations were used. CAC was detectable in 80% of individuals with diabetes (median score 84, range 0-5,776). Extent of CAC, adjusted for age, was positively associated with male sex (P = 0.0003), reduced HDL (P = 0.02), albumin-to-creatinine ratio (P = 0.008), and cigarette pack-years (P = 0.03). CAC was also positively associated with a history of angina, myocardial infarction, stroke, and vascular procedures (all P < 0.01). HbA1c and fasting glucose were positively, but nonsignificantly, associated with the extent of CAC (P = 0.14 and 0.08, respectively). CAC, adjusted for age, sex, race, and diabetes status, was heritable (h2 = 0.50; P = 0.009). In multivariate analysis with additional adjustment for HDL, BMI, hypertension, and smoking, h2 = 0.40 (P = 0.038). These results suggest that strong (independent) genetic factors as well as environmental factors contribute to the variance of CAC in individuals with type 2 diabetes. In these data, CAC seems heritable and may serve as an important feature in designing studies to map genes contributing to both atherosclerosis and type 2 diabetes.

Aged↗

PubMed2000

Age and other risk factors for neuropsychologic decline in patients undergoing coronary artery bypass graft surgery.

OBJECTIVE: To evaluate if increasing age is a major determinant of long-term neuropsychologic (NP) dysfunction in patients undergoing coronary artery bypass graft (CABG) surgery. DESIGN: Prospective cohort study. SETTING: A single university hospital. PARTICIPANTS: Three hundred eighty-one patients undergoing elective CABG surgery. INTERVENTIONS: Baseline preoperative and intraoperative characteristics were assessed for all patients. A comprehensive NP test battery was conducted preoperatively and at 1 month postoperatively. MEASUREMENTS AND MAIN RESULTS: Of the initial 381 patients, 319 (84%) returned for the 1-month visit. The overall incidence of an NP deficit was 21.6%. There was no significant difference seen with increasing age, although a trend was observed with highest NP deficit rate in the older than 65 age group. Other preoperative risk factors, including gender, education level, and preexisting diseases, were nonsignificant. Intraoperative variables were evaluated and revealed no significant differences across the age groups. CONCLUSIONS: This cohort study did not find an increased incidence of NP deficits in elderly patients after CABG surgery. It has addressed the limitations of other studies, however, with (1) a comprehensive NP test battery, (2) longer-term follow-up, and (3) adequate sample size.

Adult↗

PubMed2000

Lipoprotein concentrations and carotid atherosclerosis by diabetes status: results from the Insulin Resistance Atherosclerosis Study.

OBJECTIVE: Lipoprotein concentrations are associated with the development of atherosclerosis in people with and without diabetes. The relative strength of these associations could differ by diabetes status as a result of diabetes-related lipoprotein modifications. RESEARCH DESIGN AND METHODS: The associations between lipoprotein concentrations and internal and common carotid artery intimal-medial thickness (IMT) assessed by B-mode ultrasonography were examined by diabetes status in a cross-sectional analysis among 1,391 participants in the Insulin Resistance Atherosclerosis Study. Participants included 442 individuals with type 2 diabetes, 308 with impaired glucose tolerance, and 641 with normal glucose tolerance. RESULTS: The differences in internal and common carotid IMT between the highest and lowest tertiles of LDL were 58.1 microm (P = 0.054) and 51.0 microm (P < 0.001), respectively. The differences in internal and common carotid IMT between the lowest and highest tertiles of HDL were 56.2 microm (P = 0.07) and 37.8 microm (P = 0.003), respectively Triglycerides and VLDL were not associated with IMT. These associations did not differ significantly because of diabetes status. CONCLUSIONS: These results support the importance of dyslipidemia as a major risk factor for atherosclerosis in people with diabetes. Future research in humans should measure lipoprotein oxidizability, glycation, size, and composition directly in people of differing glucose tolerance status to address the importance of diabetes-related lipoprotein modifications more conclusively.

Carotid Arteries↗

PubMed1999

Environmental tobacco smoke and measures of subclinical vascular disease.

Assessing the relationship of exposure to environmental tobacco smoke (ETS) with subclinical measures of atherosclerotic disease supplements the epidemiologic data on fatal and nonfatal cardiovascular events. In addition, such assessment offers the opportunity to study smaller populations (including subgroups within larger studies) through improved statistical precision relative to the analysis of the relationship of ETS and clinical events and provides insights into the mechanisms of the harmful effects of ETS. In this article we review the published literature on the relationship of ETS with several indices of subclinical atherosclerosis including carotid artery intimal-medial thickness, brachial artery endothelial functioning, and silent cerebral infarctions. In each of these domains, exposure to ETS is associated with evidence of increased subclinical vascular disease.

Arteriosclerosis↗

PubMed1998

Cigarette smoking and progression of atherosclerosis: The Atherosclerosis Risk in Communities (ARIC) Study.

CONTEXT: Cigarette smoking is a powerful risk factor for incident heart disease and stroke, but the relationship of active and passive smoking with the progression of atherosclerosis has not been described. OBJECTIVE: To examine the impact of active smoking and exposure to environmental tobacco smoke (ETS) on the progression of atherosclerosis. DESIGN: A longitudinal assessment of the relationship between smoking exposure evaluated at the initial visit and the 3-year change in atherosclerosis. SETTING: A population-based cohort of middle-aged adults from 4 communities in the United States. PARTICIPANTS: A total of 10914 participants from the Atherosclerosis Risk in Communities (ARIC) study enrolled between 1987 and 1989. MAIN OUTCOME MEASURE: Change in atherosclerosis from baseline to the 3-year follow-up as indexed by intimal-medial thickness of the carotid artery assessed by ultrasound and adjusted for demographic characteristics, cardiovascular risk factors, and lifestyle variables. RESULTS: Exposure to cigarette smoke was associated with progression of atherosclerosis. Relative to never smokers and after adjustment for demographic characteristics, cardiovascular risk factors, and lifestyle variables, current cigarette smoking was associated with a 50% increase in the progression of atherosclerosis (mean progression rate over 3 years, 43.0 microm for current and 28.7 microm for never smokers, regardless of ETS exposure), and past smoking was associated with a 25% increase (mean progression rate over 3 years, 35.8 microm for past smokers and 28.7 microm for never smokers). Relative to those not exposed to ETS, exposure to ETS was associated with a 20% increase (35.2 microm for those exposed to ETS vs 29.3 microm for those not exposed). The impact of smoking on atherosclerosis progression was greater for subjects with diabetes and hypertension. Although more pack-years of exposure was independently associated with faster progression (P<.001), after controlling for the number of pack-years, the progression rates of current and past smokers did not differ (P=.11). CONCLUSIONS: Both active smoking and ETS exposure are associated with the progression of an index of atherosclerosis. Smoking is of particular concern for patients with diabetes and hypertension. The fact that pack-years of smoking but not current vs past smoking was associated with progression of atherosclerosis suggests that some adverse effects of smoking may be cumulative and irreversible.

Arteriosclerosis↗

PubMed1998

Ten-year trends in cigarette smoking among young adults, 1986-1996: the CARDIA study. Coronary Artery Risk Development In Young Adults.

PURPOSE: To calculate ten-year smoking trends in a longitudinal cohort of young adults, and to characterize trends by race, sex, education, and birth cohort. METHODS: Data on cigarette smoking have been collected for ten years (1986-1996) from 5115 black and white men and women, aged 18-30 years, participating in the Coronary Artery Risk Development In Young Adults (CARDIA) study. Regression analysis adjusting for intra-person correlation over time and weighting for factors affecting follow-up was used to estimate change in smoking rates. RESULTS: Overall, smoking rates declined in white women (-0.50%/year, p < 0.001) and white men (-0.24%/year, p = 0.03). Rates remained stable in black women and increased in black men (0.37%/year, p = 0.01). Declining rates were generally observed in white women of all educational levels and birth cohorts and in several subgroups of white men. Increasing rates among black men could be attributed primarily to increasing rates in the youngest birth cohort. Among black men and women, prevalence of smoking in 1986 was considerably lower in the youngest birth cohort compared to the oldest; however, the increasing rates of change in smoking rates observed among the youngest birth cohorts (and decreasing rates in the oldest) lessened the disparity in prevalence rates across birth cohorts by 1996. Smoking initiation rates were highest among black men; cessation rates were highest among white women. CONCLUSIONS: These findings confirm that declines in smoking prevalence are not occurring across all groups, and reveal populations in special need of targeted interventions, particularly young black men.

Adolescent↗

PubMed1998

Ability of alternative indices of insulin sensitivity to predict cardiovascular risk: comparison with the "minimal model". Insulin Resistance Atherosclerosis Study (IRAS) Investigators.

INTRODUCTION: Although recognition of insulin sensitivity as a risk factor for cardiovascular disease is growing, a deeper understanding of its role is impeded by the cost and complexity of currently available measures. This report evaluates previously described alternative indices of insulin sensitivity with the goal of identifying a reliable, but logistically simpler, alternative. METHODS: Data from 1460 participants in the Insulin Resistance Atherosclerosis Study (IRAS) were used to assess the proportion of the relationship between a recognized measure of insulin sensitivity (Bergman's SI) and cardiovascular risk factors that is contained in each of nine alternative measures. RESULTS: A number of the alternative indices contained a substantial proportion of the information available in Bergman's SI. The Galvin's index and the homeostasis model were most promising. However, there remained a significant amount of the information in Bergman's SI that was not contained in any of the alternative indices. DISCUSSION: There are simpler alternative indices of insulin sensitivity for use in epidemiological studies, but each alternative is associated with some loss of information. It may be possible that this loss can be overcome with an increased sample size; however, using the alternative indices may also confound the assessment of insulin sensitivity with other underlying factors (i.e., hyperinsulinemia). The alternative indices are not recommended for the clinical assessment of insulin sensitivity for an individual patient or subject.

Cardiovascular Diseases↗