Weight Loss Programs May Have Beneficial or Adverse Effects on Fat Mass and Insulin Sensitivity in Overweight and Obese Black Women.

Objective: Weight loss interventions have produced little change in insulin sensitivity in black women, but mean data may obscure metabolic benefit to some and adverse effects for others. Accordingly, we analyzed insulin sensitivity relative to fat mass change following a weight loss program.

Design And Methods: Fifty-four black women (BMI range 25.

Incidence of cardiac arrhythmias in asymptomatic hereditary hemochromatosis subjects with C282Y homozygosity.

It is not well known whether systemic iron overload per se in hereditary hemochromatosis (HH) is associated with cardiac arrhythmias before other signs and symptoms of cardiovascular disease occur. In the present study, we examined the incidence of cardiac arrhythmia in cardiac asymptomatic subjects with HH (New York Heart Association functional class I) and compared it to that in age- and gender-matched normal volunteers. The 42 subjects with HH and the 19 normal control subjects were recruited through the National Heart, Lung, and Blood Institute-sponsored "Heart Study of Hemochromatosis.

High-density lipoprotein cholesterol efflux, nitration of apolipoprotein A-I, and endothelial function in obese women.

Subjects at risk of atherosclerosis might have dysfunctional high-density lipoprotein (HDL) despite normal cholesterol content in the plasma. We considered whether the efflux of excess cellular cholesterol to HDL from obese subjects is associated with impaired arterial endothelial function, a biomarker of cardiovascular risk. A total of 54 overweight (body mass index [BMI] 25 to 29.

Variability of C-reactive protein levels among patients with stable coronary artery disease and on statin therapy.

Background: High sensitivity C-reactive protein, a marker of inflammation, has been proposed to stratify coronary artery disease risk and is lowered by HMG-CoA reductase (statin) therapy. However, the reproducibility of persistently elevated hs-CRP levels and association with other markers of inflammation in patients with stable CAD on aggressive statin therapy is unknown.

Objectives: To determine the reproducibility of hs-CRP levels measured within 2 weeks in patients with documented CAD with stable symptoms and to identify associations with other markers of inflammation.

Targeted antagonism of CXCR4 mobilizes progenitor cells under investigation for cardiovascular disease.

Background Aims: Bone marrow (BM)-derived cells may repair cardiovascular injury but populations of interest circulate in small numbers. Cytokines such as granulocyte-colony-stimulating factor mobilize cells under investigation for this purpose, including CD133+ but require injections over multiple days and may promote inflammation. The purpose of this study was to evaluate the effects of a novel CXCR4 inhibitor (plerixafor), previously shown to mobilize CD34+ stem cells, on CD133+ mobilization and markers of inflammation.

Microarray-based characterization of a colony assay used to investigate endothelial progenitor cells and relevance to endothelial function in humans.

Objective: An assay proposed to quantify endothelial progenitor cell (EPC) colonies in humans was investigated to determine the phenotype of recovered cells and their relevance to in vivo endothelial function.

Methods And Results: Twelve sedentary subjects participating in a worksite wellness program underwent endothelial flow-mediated dilation (FMD) testing of the brachial artery and blood sampling for EPC colony assay. Microarray-based genotypic characterization of colonies showed surface markers consistent with T lymphocyte phenotype, but not with an EPC (CD34, CD133, VEGFR-2) or endothelial (CD146) phenotype.

Predictors of endothelial function in employees with sedentary occupations in a worksite exercise program.

A sedentary workforce may be at increased risk for future cardiovascular disease. Exercise at the work site has been advocated, but effects on endothelium as a biomarker of risk and relation to weight loss, lipid changes, or circulating endothelial progenitor cells (EPCs) have not been reported. Seventy-two office and laboratory employees (58 women; average age 45 years, range 22 to 62; 26 with body mass index values >30 kg/m(2)) completed 3 months of participation in the National Heart, Lung, and Blood Institute's Keep the Beat program, with the determination of vital signs, laboratory data, and peak oxygen consumption (VO(2)) during treadmill exercise.

Relation of endothelial function to cardiovascular risk in women with sedentary occupations and without known cardiovascular disease.

Our purpose was to determine predictors of endothelial function and potential association with cardiovascular risk in women with sedentary occupations, in whom obesity-associated risk factors may contribute to excess morbidity and mortality. Ninety consecutive women (age range 22 to 63 years, 22 overweight (body mass index [BMI] > or =25 to 29.9 kg/m(2)) and 42 obese (BMI > or = 30 kg/m(2)), had vital signs, lipids, insulin, glucose, high-sensitivity C-reactive protein, and sex hormones measured.

Endothelial progenitor cell mobilization and increased intravascular nitric oxide in patients undergoing cardiac rehabilitation.

Purpose: We investigated whether cardiac rehabilitation participation increases circulating endothelial progenitor cells (EPCs) and benefits vasculature in patients already on stable therapy previously shown to augment EPCs and improve endothelial function.

Methods: Forty-six of 50 patients with coronary artery disease completed a 36-session cardiac rehabilitation program: 45 were treated with HMG-CoA reductase inhibitor (statin) therapy > or = 1 month (average baseline low-density lipoprotein cholesterol = 81 mg/dL). Mononuclear cells isolated from blood were quantified for EPCs by flow cytometry (CD133/VEGFR-2 cells) and assayed in culture for EPC colony-forming units (CFUs).

Endogenous endothelin in human coronary vascular function: differential contribution of endothelin receptor types A and B.

Endothelin 1 mediates coronary vasoconstriction and endothelial dysfunction via endothelin receptor type A (ET(A)) activation. However, the effects of selective endothelin receptor type B (ET(B)) and combined ET(A+B) receptor blockade on coronary vasomotion are unknown. We measured coronary vascular tone and endothelium-dependent and -independent vasomotor function before and after selective infusion of BQ-788 (an ET(B) receptor antagonist) or combined infusion of BQ-788+BQ-123 (an ET(A) antagonist) into unobstructed coronary arteries of 39 patients with coronary atherosclerosis or risk factors undergoing cardiac catheterization.

Outcomes and risks of granulocyte colony-stimulating factor in patients with coronary artery disease.

Objectives: Cytokine mobilization of progenitor cells from bone marrow may promote myocardial neovascularization with relief of ischemia.

Background: Patients with coronary artery disease (CAD) have low numbers of endothelial progenitor cells compared with healthy subjects.

Methods: Granulocyte colony-stimulating factor (G-CSF), 10 microg/kg/day for five days, was administered to 16 CAD patients.

Nitrite reduction to nitric oxide by deoxyhemoglobin vasodilates the human circulation.

Nitrite anions comprise the largest vascular storage pool of nitric oxide (NO), provided that physiological mechanisms exist to reduce nitrite to NO. We evaluated the vasodilator properties and mechanisms for bioactivation of nitrite in the human forearm. Nitrite infusions of 36 and 0.

Circulating endothelial progenitor cells, vascular function, and cardiovascular risk.

Background: Cardiovascular risk factors contribute to atherogenesis by inducing endothelial-cell injury and dysfunction. We hypothesized that endothelial progenitor cells derived from bone marrow have a role in ongoing endothelial repair and that impaired mobilization or depletion of these cells contributes to endothelial dysfunction and cardiovascular disease progression.

Methods: We measured the number of colony-forming units of endothelial progenitor cells in peripheral-blood samples from 45 men (mean [+/-SE] age, 50+/-2 years).

The effect of sildenafil on human vascular function, platelet activation, and myocardial ischemia.

Objective: We studied the effects of sildenafil, a phosphodiesterase 5 inhibitor, on coronary and peripheral vascular function, platelet activation, and myocardial ischemia.

Background: Nitric oxide vasodilates and inhibits platelet activation by generating cyclic guanosine 5'-monophosphate, which is metabolized by phosphodiesterase type 5.

Methods: The effect of oral sildenafil on resting coronary vascular tone, endothelium-dependent and -independent function and platelet activation was measured in 24 patients.

Prognostic value of coronary vascular endothelial dysfunction.

Background: Whether patients at increased risk can be identified from a relatively low-risk population by coronary vascular function testing remains unknown. We investigated the relationship between coronary endothelial function and the occurrence of acute unpredictable cardiovascular events (cardiovascular death, myocardial infarction, stroke, and unstable angina) in patients with and without coronary atherosclerosis (CAD).

Methods And Results: We measured the change in coronary vascular resistance (DeltaCVR) and epicardial diameter with intracoronary acetylcholine (ACh, 15 micro g/min) to test endothelium-dependent function and sodium nitroprusside (20 micro g/min) and adenosine (2.