Tobacco smoking is a risk factor for peripheral arterial disease. During oral glucose tolerance tests (OGTT) in a population study the author and co-workers have earlier shown that smokers have higher blood glucose values early postload and lower values at two hours compared with nonsmokers. Eighty-three patients, all with intermittent claudication but with a normal OGTT, have now been studied according to their response to an oral glucose load. The blood flow resistance during reactive hyperemia, as measured with a calf plethysmograph, was compared between subjects in the quartile of patients with the highest forty-five-minute blood glucose and those in the lowest quartile. The blood flow resistance was significantly higher in the group with a high forty-five-minute blood glucose, 13.3 +/- 1.34 vs 9.5 +/- 0.65 (mean +/- SEM), p less than 0.02. Blood pressure and blood lipids were similar in the two groups. It is suggested that an exaggerated early response in the OGTT might be an independent risk factor for peripheral arterial disease.