Acute reduction in ankle brachial index following smoking in chronic smokers with peripheral arterial occlusive disease

The ankle-brachial systolic pressure index (ABI), a noninvasive measure of peripheral arterial occlusive disease (PAOD) severity, is considered a mark er of atherosclerosis and an independent predictor of mortality. However, i t is not known whether factors other than PAOD severity, such as cigarette smoking, have an effect on ABI measurement. Therefore, the authors examined the acute effects of cigarette smoking on ABI and the peripheral circulati on in 10 older (63 +/-10 years) chronic smokers (39 +/-37 pack-years) with PAOD (ABI=0.64 +/-0.14). The patients were instructed to refrain from smoki ng and from consuming caffeine-containing beverages for at least 12 hours b efore the tests. The patients were randomly assigned to 2 days of testing c onsisting of a nonsmoking and a smoking day. Resting heart rate, blood pres sure, ABI, and calf blood flow by plethysmography were obtained on both tes ting days. The smoking day consisted of smoking two filter cigarettes over a period of 10 minutes before the measurement of ABI and calf blood flow. T he ABI on the smoking day (0.55 +/-0.11) was lower (p=0.008) than on the no nsmoking day (0.64 +/-0.14) owing to a lower (p=0.020) ankle systolic blood pressure (81 +/-28 vs 93 +/-28 mmHg). Brachial systolic blood pressures, h eart rate, and calf blood flow were not altered by smoking (p>0.05). These results demonstrate that the acute effect of cigarette smoking lowers the A BI in chronic smokers with intermittent claudication, thereby yielding evid ence of a transient deleterious effect of cigarette smoking on the peripher al circulation in chronic smokers.