Effect of a short-term primary prevention program on endothelium-dependent vasodilation in adults at risk for atherosclerosis

BACKGROUND: Endothelium-dependent vasodilation is impaired in asymptomatic subjects with risk factors for atherosclerosis. PURPOSE: To determine whether a three-month integrative primary prevention program can improve endothelial function in asymptomatic subjects with risk factors for atherosclerosis. PATIENTS AND METHODS: Twenty-two asymptomatic middle-aged men and women (13 men and nine women) aged 55 +/- 7 years with sedentary lifestyle and dyslipidemia (low density lipoprotein LDL] level greater than 3.4 mmol/L) underwent an exercise test, determination of fasting blood lipid levels and noninvasive measurement of brachial artery reactivity before and three months after the beginning of a prevention program. The program consisted of exercise training (three times per week) and National Cholesterol Education Program step 1 diet in all subjects. A smoking cessation program was offered when applicable (six patients). Brachial artery diameter was measured by using high resolution ultrasound at rest, during reactive hyperemia (flow-mediated dilation FMD], which is endothelium-dependent) and after sublingual nitroglycerin (NTG) (endothelium-independent vasodilation). RESULTS: After three months, peak oxygen uptake increased significantly from 25.4 +/- 4.9 to 27.5 +/- 4.8 mL/kg/min (P < 0.005), and LDL level decreased significantly from 4.48 +/- 0.92 to 4.00 +/- 0.83 mmol/L (P < 0.005). FMD and NTG responses assessed as percentage of diameter change from baseline, however, did not change (FMD 5.4 +/- 4.3% before and 5.1 +/- 3.9% at three months, not significant; NTG 8.4 +/- 3.8% before and 7.4 +/- 4.5% at three months, not significant). CONCLUSIONS: Short-term application of the currently recommended lifestyle intervention in adults with coronary risk factors did not improve vascular endothelial function. Longer and more aggressive programs may be needed to improve vascular function in subjects with risk factors for atherosclerosis.