The risk of type 2 diabetes mellitus is heterogeneous among obese individuals. Factors that discriminate prediabetes or diabetes risk within this population have not been well characterized. A ...dysfunctional adiposity phenotype, characterized by excess visceral fat and insulin resistance, may contribute to diabetes development in those with obesity.
To investigate associations between adiposity phenotypes and risk for incident prediabetes and diabetes in a multiethnic, population-based cohort of obese adults.
Among 732 obese participants (body mass index ≥30) aged 30 to 65 years without diabetes or cardiovascular disease enrolled between 2000 and 2002 in the Dallas Heart Study, we measured body composition by dual energy x-ray absorptiometry and magnetic resonance imaging (MRI); circulating adipokines and biomarkers of insulin resistance, dyslipidemia, and inflammation; and subclinical atherosclerosis and cardiac structure and function by computed tomography and MRI.
Incidence of diabetes through a median 7.0 years (interquartile range, 6.6-7.6) of follow-up. In a subgroup of 512 participants with normal fasting glucose values at baseline, incidence of the composite of prediabetes or diabetes was determined.
Of the 732 participants (mean age, 43 years; 65% women; 71% nonwhite), 84 (11.5%) developed diabetes. In multivariable analysis, higher baseline visceral fat mass (odds ratio OR per 1 SD 1.4 kg, 2.4; 95% CI, 1.6-3.7), fructosamine level (OR per 1 SD 1.1 μmol/L, 2.0; 95% CI, 1.4-2.7), fasting glucose level (OR per 1 SD 1.1 μmol/L, 1.9; 95% CI, 1.4-2.6), family history of diabetes (OR, 2.3; 95% CI, 1.3-4.3), systolic blood pressure (OR per 10 mm Hg, 1.3; 95% CI, 1.1-1.5), and weight gain over follow-up (OR per 1 kg, 1.06; 95% CI, 1.02-1.10) were independently associated with diabetes, with no associations observed for body mass index, total body fat, or abdominal subcutaneous fat. Among the 512 participants with normal baseline glucose values, the composite outcome of prediabetes or diabetes occurred in 39.1% and was independently associated with baseline measurements of visceral fat mass; levels of fasting glucose, insulin, and fructosamine; older age; nonwhite race; family history of diabetes; and weight gain over follow-up (P < .05 for each) but not with measurements of general adiposity.
Excess visceral fat and insulin resistance, but not general adiposity, were independently associated with incident prediabetes and type 2 diabetes mellitus in obese adults.
Abstract Background Lower leisure-time physical activity (LTPA) and higher body mass index (BMI) are independently associated with risk of heart failure (HF). However, it is unclear if this ...relationship is consistent for both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF). Objectives This study sought to quantify dose–response associations between LTPA, BMI, and the risk of different HF subtypes. Methods Individual-level data from 3 cohort studies (WHI Women’s Health Initiative, MESA Multi-Ethnic Study of Atherosclerosis, and CHS Cardiovascular Health Study) were pooled and participants were stratified into guideline-recommended categories of LTPA and BMI. Associations between LTPA, BMI, and risk of overall HF, HFpEF (ejection fraction ≥45%), and HFrEF (ejection fraction <45%) were assessed by using multivariable adjusted Cox models and restricted cubic splines. Results The study included 51,451 participants with 3,180 HF events (1,252 HFpEF, 914 HFrEF, and 1,014 unclassified HF). In the adjusted analysis, there was a dose-dependent association between higher LTPA levels, lower BMI, and overall HF risk. Among HF subtypes, LTPA in any dose range was not associated with HFrEF risk. In contrast, lower levels of LTPA (<500 MET-min/week) were not associated with HFpEF risk, and dose-dependent associations with lower HFpEF risk were observed at higher levels. Compared with no LTPA, higher than twice the guideline-recommended minimum LTPA levels (>1,000 MET-min/week) were associated with an 19% lower risk of HFpEF (hazard ratio: 0.81; 95% confidence interval: 0.68 to 0.97). The dose–response relationship for BMI with HFpEF risk was also more consistent than with HFrEF risk, such that increasing BMI above the normal range (≥25 kg/m2 ) was associated with a greater increase in risk of HFpEF than HFrEF. Conclusions Our study findings show strong, dose–dependent associations between LTPA levels, BMI, and risk of overall HF. Among HF subtypes, higher LTPA levels and lower BMI were more consistently associated with lower risk of HFpEF compared with HFrEF.
Metabolic syndrome (MetS) is characterized by adiposity and atherogenic dyslipidemia consisting of elevated triglyceride and decreased high density lipoprotein cholesterol (HDL-C) levels however, ...cholesterol concentration alone does not reflect HDL functionality. Cholesterol efflux capacity (CEC) captures a key anti-atherosclerotic function of HDL; studies linking CEC to MetS have yielded inconsistent findings and lacked racial/ethnic diversity. The aim of this study was to evaluate the association between CEC and MetS in a large multi-ethnic population utilizing two different CEC assays interrogating overlapping but distinct reverse cholesterol transport pathways. A cross-sectional study was performed using the Dallas Heart Study cohort and cholesterol efflux was measured with radiolabeled and fluorescent cholesterol assays. The relationship between CEC and MetS was assessed using multivariable regression analyses. A total of 2241 participants were included (mean age was 50 years; 38% men and 53% Blacks). CEC was independently and inversely associated with MetS irrespective of efflux assay (CEC-radiolabeled, adjusted OR 0·71 95% CI 0·65-0·80. CEC-fluorescent, adjusted OR 0·85 95% CI 0·77-0·94). Both CEC measures were inversely associated with waist circumference and directly associated with HDL-C but not with other MetS components. There was an interaction by sex but not by race such that the inverse associations between CEC and MetS were somewhat attenuated in men (OR 0·86, 95%CI 0·74-1·01). In this large multi-ethnic cohort, impaired CEC is linked to MetS irrespective of efflux assay and race/ethnicity but less so among men. Future studies are needed to assess whether CEC mediates the atherosclerotic cardiovascular disease risk of MetS.
Few data are available comparing cardiovascular disease (CVD) biomarker profiles between women and men in the general population. We analyzed sex-based differences in multiple biomarkers reflecting ...distinct pathophysiological pathways, accounting for differences between women and men in CVD risk factors, body composition, and cardiac morphology.
A cross-sectional analysis was performed using data from the Dallas Heart Study, a multiethnic population-based study. Associations between sex and 30 distinct biomarkers representative of 6 pathophysiological categories were evaluated using multivariable linear regression adjusting for age, race, traditional CVD risk factors, kidney function, insulin resistance, MRI and dual-energy x-ray absorptiometry measures of body composition and fat distribution, and left ventricular mass.
After excluding participants with CVD, the study population included 3439 individuals, mean age 43 years, 56% women, and 52% black. Significant sex-based differences were seen in multiple categories of biomarkers, including lipids, adipokines, and biomarkers of inflammation, endothelial dysfunction, myocyte injury and stress, and kidney function. In fully adjusted models, women had higher levels of high-density lipoprotein cholesterol and high-density lipoprotein particle concentration, leptin, d-dimer, homoarginine, and N-terminal pro B-type natriuretic peptide, and lower levels of low-density lipoprotein cholesterol, adiponectin, lipoprotein-associated phospholipase A2 mass and activity, monocyte chemoattractant protein-1, soluble endothelial cell adhesion molecule, symmetrical dimethylarginine, asymmetrical dimethylarginine, high-sensitivity troponin T, and cystatin C.
Biomarker profiles differ significantly between women and men in the general population. Sex differences were most apparent for biomarkers of adiposity, endothelial dysfunction, inflammatory cell recruitment, and cardiac stress and injury. Future studies are needed to characterize whether pathophysiological processes delineated by these biomarkers contribute to sex-based differences in the development and complications of CVD.
Objectives The study sought to determine the 99th percentile upper reference limit for the high-sensitivity cardiac troponin T assay (hs-cTnT) in 3 large independent cohorts. Background The presently ...recommended 14 ng/l cut point for the diagnosis of myocardial infarction using the hs-cTnT assay was derived from small studies of presumably healthy individuals, with relatively little phenotypic characterization. Methods Data were included from 3 well-characterized population-based studies: the Dallas Heart Study (DHS), the Atherosclerosis Risk in Communities (ARIC) Study, and the Cardiovascular Health Study (CHS). Within each cohort, reference subcohorts were defined excluding individuals with recent hospitalization, overt cardiovascular disease, and kidney disease (subcohort 1), and further excluding those with subclinical structural heart disease (subcohort 2). Data were analyzed stratified by age, sex, and race. Results The 99th percentile values for the hs-cTnT assay in DHS, ARIC, and CHS were 18, 22, and 36 ng/l (subcohort 1) and 14, 21, and 28 ng/l (subcohort 2), respectively. These differences in 99th percentile values paralleled age differences across cohorts. Analyses within sex/age strata yielded similar results between cohorts. Within each cohort, 99th percentile values increased with age and were higher in men. More than 10% of men 65 to 74 years of age with no cardiovascular disease in our study had cardiac troponin T values above the current myocardial infarction threshold. Conclusions Use of a uniform 14 ng/l cutoff for the hs-cTnT assay may lead to over-diagnosis of myocardial infarction, particularly in men and the elderly. Clinical validation is needed of new age- and sex-specific cutoff values for this assay.
It is unclear whether high-density lipoprotein (HDL) cholesterol concentration plays a causal role in atherosclerosis. A more important factor may be HDL cholesterol efflux capacity, the ability of ...HDL to accept cholesterol from macrophages, which is a key step in reverse cholesterol transport. We investigated the epidemiology of cholesterol efflux capacity and its association with incident atherosclerotic cardiovascular disease outcomes in a large, multiethnic population cohort.
We measured HDL cholesterol level, HDL particle concentration, and cholesterol efflux capacity at baseline in 2924 adults free from cardiovascular disease who were participants in the Dallas Heart Study, a probability-based population sample. The primary end point was atherosclerotic cardiovascular disease, defined as a first nonfatal myocardial infarction, nonfatal stroke, or coronary revascularization or death from cardiovascular causes. The median follow-up period was 9.4 years.
In contrast to HDL cholesterol level, which was associated with multiple traditional risk factors and metabolic variables, cholesterol efflux capacity had minimal association with these factors. Baseline HDL cholesterol level was not associated with cardiovascular events in an adjusted analysis (hazard ratio, 1.08; 95% confidence interval CI, 0.59 to 1.99). In a fully adjusted model that included traditional risk factors, HDL cholesterol level, and HDL particle concentration, there was a 67% reduction in cardiovascular risk in the highest quartile of cholesterol efflux capacity versus the lowest quartile (hazard ratio, 0.33; 95% CI, 0.19 to 0.55). Adding cholesterol efflux capacity to traditional risk factors was associated with improvement in discrimination and reclassification indexes.
Cholesterol efflux capacity, a new biomarker that characterizes a key step in reverse cholesterol transport, was inversely associated with the incidence of cardiovascular events in a population-based cohort. (Funded by the Donald W. Reynolds Foundation and others.).
Elevated lipoprotein(a) (Lpa) and family history (FHx) of coronary heart disease (CHD) are individually associated with cardiovascular risk, and Lp(a) is commonly measured in those with FHx.
The aim ...of this study was to determine independent and joint associations of Lp(a) and FHx with atherosclerotic cardiovascular disease (ASCVD) and CHD among asymptomatic subjects.
Plasma Lp(a) was measured and FHx was ascertained in 2 cohorts. Elevated Lp(a) was defined as the highest race-specific quintile. Independent and joint associations of Lp(a) and FHx with cardiovascular risk were determined using Cox regression models adjusted for cardiovascular risk factors.
Among 12,149 ARIC (Atherosclerosis Risk In Communities) participants (54 years, 56% women, 23% black, 44% with FHx), 3,114 ASCVD events were observed during 21 years of follow-up. FHx and elevated Lp(a) were independently associated with ASCVD (hazard ratio HR: 1.17; 95% confidence interval CI: 1.09 to 1.26, and HR: 1.25; 95% CI: 1.12 to 1.40, respectively), and no Lp(a)-by-FHx interaction was noted (p = 0.75). Compared with subjects without FHx and nonelevated Lp(a), those with either elevated Lp(a) or FHx were at a higher ASCVD risk, while those with both had the highest risk (HR: 1.43; 95% CI: 1.27 to 1.62). Similar findings were observed for CHD risk in ARIC, in analyses stratified by premature FHx, and in an independent cohort, the DHS (Dallas Heart Study). Presence of both elevated Lp(a) and FHx resulted in greater improvement in ASCVD and CHD risk reclassification and discrimination indexes than either marker alone.
Elevated plasma Lp(a) and FHx have independent and additive joint associations with cardiovascular risk and may be useful concurrently for guiding primary prevention therapy decisions.
Cholesterol efflux capacity (CEC), which is a key step in the reverse cholesterol transport pathway, is independently associated with atherosclerotic cardiovascular disease (ASCVD). However, whether ...it predicts ASCVD beyond validated novel risk markers is unknown.
This study assessed if CEC improved ACSVD risk prediction beyond using coronary artery calcium (CAC), family history (FH), and high-sensitivity C-reactive protein (hs-CRP).
CEC, CAC, self-reported FH, and hs-CRP were assessed among participants without baseline ASCVD who were enrolled in the Dallas Heart Study (DHS). ASCVD was defined as a first nonfatal myocardial infarction (MI) or stroke, coronary revascularization, or cardiovascular death, assessed over a median 9.4 years. Risk prediction was assessed using various modeling techniques and improvements in the c-statistic, the integrated discrimination index (IDI), and the net reclassification index (NRI).
The mean age of the population (N = 1,972) was 45 years, 52% had CAC (>0), 31% had FH, and 58% had elevated hs-CRP (≥2 mg/l). CEC greater than the median was associated with a 50% reduced incidence of ASCVD in those with CAC (5.4% vs. 10.5%; p = 0.003), FH (5.8% vs. 10%; p = 0.05), and elevated hs-CRP (3.8% vs. 7.9%; p = 0.004). CEC improved all metrics of discrimination and reclassification when added to CAC (c-statistic, p = 0.004; IDI, p = 0.02; NRI: 0.38; 95% confidence interval CI: 0.13 to 0.53), FH (c-statistic, p = 0.006; IDI, p = 0.008; NRI: 0.38; 95% CI: 0.13 to 0.55), or elevated hs-CRP (c-statistic p = 0.008; IDI p = 0.02; NRI: 0.36; 95% CI 0.12 to 0.52).
CEC improves ASCVD risk prediction beyond using CAC, FH, and hs-CRP and warrants consideration as a novel ASCVD risk marker.
Elevated lipoprotein(a) Lp(a) and coronary artery calcium (CAC) score are individually associated with increased atherosclerotic cardiovascular disease (ASCVD) risk but have not been studied in ...combination.
This study sought to investigate the independent and joint association of Lp(a) and CAC with ASCVD risk.
Plasma Lp(a) and CAC were measured at enrollment among asymptomatic participants of the MESA (Multi-Ethnic Study of Atherosclerosis) (n = 4,512) and DHS (Dallas Heart Study) (n = 2,078) cohorts. Elevated Lp(a) was defined as the highest race-specific quintile, and 3 CAC score categories were studied (0, 1-99, and ≥100). Associations of Lp(a) and CAC with ASCVD risk were evaluated using risk factor–adjusted Cox regression models.
Among MESA participants (61.9 years of age, 52.5% women, 36.8% White, 29.3% Black, 22.2% Hispanic, and 11.7% Chinese), 476 incident ASCVD events were observed during 13.2 years of follow-up. Elevated Lp(a) and CAC score (1-99 and ≥100) were independently associated with ASCVD risk (HR: 1.29; 95% CI: 1.04-1.61; HR: 1.68; 95% CI: 1.30-2.16; and HR: 2.66; 95% CI: 2.07-3.43, respectively), and Lp(a)-by-CAC interaction was not noted. Compared with participants with nonelevated Lp(a) and CAC = 0, those with elevated Lp(a) and CAC ≥100 were at the highest risk (HR: 4.71; 95% CI: 3.01-7.40), and those with elevated Lp(a) and CAC = 0 were at a similar risk (HR: 1.31; 95% CI: 0.73-2.35). Similar findings were observed when guideline-recommended Lp(a) and CAC thresholds were considered, and findings were replicated in the DHS.
Lp(a) and CAC are independently associated with ASCVD risk and may be useful concurrently for guiding primary prevention therapy decisions.
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Objectives The goal of this study was to determine if biomarkers of subclinical myocardial injury and hemodynamic stress identify asymptomatic individuals with left ventricular hypertrophy (LVH) at ...higher risk for heart failure (HF) and death. Background The interaction between LVH, low but detectable cardiac troponin T (cTnT), and elevated N-terminal pro–B-type natriuretic peptide (NT-proBNP) on cardiovascular (CV) outcomes in the general population is unknown. Methods Participants in the Dallas Heart Study without clinical HF, LV dysfunction, or chronic kidney disease underwent measurement of LV mass by magnetic resonance imaging (MRI), cTnT by highly sensitive assay, and NT-proBNP analysis (n = 2,413). Subjects were stratified according to LVH and by detectable cTnT (≥3 pg/ml) and increased NT-proBNP (>75th age- and sex-specific percentile) levels. For each analysis, participants were categorized into groups based on the presence (+) or absence (–) of LVH and biomarker levels above (+) or below (–) the predefined threshold. Results Nine percent of participants were LVH+, 25% cTnT+, and 24% NT-proBNP+. Those LVH+ and cTnT+ and/or NT-proBNP+ (n = 144) were older and more likely to be male, with a greater risk factor burden and more severe LVH compared with those who were LVH+ biomarker– (p < 0.01 for each). The cumulative incidence of HF or CV death over 8 years among LVH+ cTnT+ was 21% versus 1% (LVH– cTnT–), 4% (LVH– cTnT+), and 6% (LVH+ cTnT–) (p < 0.0001). The interactions between LVH and cTnT (pinteraction = 0.0005) and LVH and NT-proBNP (pinteraction = 0.014) were highly significant. Individuals who were LVH+ and either cTnT+ or NT-proBNP+ remained at >4-fold higher risk for HF or CV death after multivariable adjustment for CV risk factors, renal function, and LV mass compared with those who were LVH– biomarker–. Conclusions Minimal elevations in biomarkers of subclinical cardiac injury and hemodynamic stress modify the association of LVH with adverse outcomes, identifying a malignant subphenotype of LVH with high risk for progression to HF and CV death.
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