Predictors of Endothelial Function in Employees With Sedentary Occupations in a Worksite Exercise Program

Abstract

A sedentary work force may be at increased risk of future cardiovascular disease. Exercise at the worksite 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. Seventytwo office and laboratory (26 with body-mass index [BMI] > 30 kg/m 2 ) employees (58 women; average age 45 years; range: 22-62 years) completed 3 months of participation in the National Heart, Lung, and Blood Institute's "Keep the Beat" program, with determination of vital signs, laboratory data and peak oxygen consumption (VO 2 ) during treadmill exercise. Brachial artery endothelium was tested by flow-mediated dilation (FMD), which at baseline was inversely associated with Framingham risk score (r=-0.3689, P<0.0001). EPCs were quantified by colony assay. With exercise averaging 98±47 (mean±SD) minutes each work week, there was improvement in FMD (from 7.8 ±3.4 to 8.5±3.0%, P=0.0096) and peak VO 2 (+1.2±3.1 mL O 2 /kg/min; P=0.0028), with reduction in diastolic blood pressure (-2±8 mmHg; P=0.0478), total cholesterol (-8±25 mg/dL, P=0.0131), lowdensity lipoprotein (LDL) cholesterol (-7±19 mg/dL, P=0.0044), but with marginal reduction in weight (-0.5±2.1 kg, P=0.0565). By multiple regression modeling, lower baseline FMD, greater age, reductions in total and LDL cholesterol and diastolic blood pressure, and increases in EPC colonies and peak VO 2 were jointly statistically significant predictors of change in FMD and accounted for 47% of the variability in FMD improvement with program participation. Results were similar when modeling was performed for women only. By contrast, neither adiposity at baseline nor change in weight were predictors of improved endothelial function. In conclusion, daily exercise achievable in the worksite by employees with sedentary occupations improves endothelial function-even with absence of weight loss--which may decrease cardiovascular risk, if sustained. Keywords endothelium; nitric oxide; obesity; lipoproteins; exercise Exercise has been associated with multiple health benefits, including favorable effects on lipids, blood pressure, insulin sensitivity and endothelial function 1-5 , yet almost two-thirds of

Current perspective of pathophysiological and interventional effects on endothelial progenitor cell biology: Focus on Pi3K/AKT/eNOS pathway

“…A 3 month exercise program offered to middle aged to old sedentary subjects resulted in a significant upregulation of EPC colony-forming and migratory capacity. These results were confirmed by Lippincott et al in a healthy sedentary population, in which a 3 month daily exercise worksite fitness program showed beneficial effects on EPC colony-forming capacity [197]. Furthermore, in older patients with stable coronary artery disease, moderate exercise training for 28 days led to a significantly higher mobilization of EPC numbers in peripheral blood.…”

Microarray-Based Characterization of a Colony Assay Used to Investigate Endothelial Progenitor Cells and Relevance to Endothelial Function in Humans

“…This study was conducted at the Clinical Center of the National Institutes of Health in employees who reported no previous exercise training and provided written informed consent for participation in this protocol, approved by the institutional review board of the National, Heart, Lung, and Blood Institute 22. Brachial artery flow-mediated dilation (FMD) testing was performed by an experienced technician who also performed the testing in Hill et al9 Peripheral blood mononuclear cells were cultured for the EPC-CFU assay (Stem Cell Technologies EndoCult Liquid Medium Kit) according to the manufacturer’s instructions.…”

“…Given the uncertainty in defining phenotype using cellular markers, we performed gene expression profiling on EPC-CFUs cultured using a commercial assay based on that used by Hill et al9 We then repeated gene expression profiling of EPC-CFUs after exercise—which has been reported to independently increase EPCs and to improve endothelial function18– 22—for 3 months in a worksite wellness program. Our purpose was to determine whether phenotypic characterization of these CFUs and changes in their gene expression patterns would provide insight into endothelial function and EPC differentiation capacity, before and after exercise training.…”

Exercício físico e disfunção endotelial

“…A study carried out by Lippincott et al 75 , analyzing individuals who had sedentary professions, observed that 15 to 20 minutes a day of daily exercises at the workplace for 3 months improved endothelial function. Moreover, there was an improvement in blood pressure and LDL-c and total cholesterol levels, which contributed to the decrease in the risk of cardiovascular events.…”