Plethysmographic pulse wave amplitude and future leg arteriosclerosis

A low pulse wave amplitude during calf plethysmography at 55 years of age was previously found to be associated with an increased mortality and incidence of myocardial infarction. In order to test the hypothesis that a low pulse wave amplitude is associated with an increased risk of future leg atherosclerosis as well, we have studied the relationship between a low ankle-brachial pressure index (ABPI; < 0.9) at 68 years of age and the pulse wave amplitude at 55 years of age in that same cohort. The prevalence of a low pulse wave amplitude (< or = 5 mm; lowest quintile) among men with a low ABPI (42%) was more than twice as high as it was among men who had a normal ABPI (19%) (P < 0.001). No association was found between a low ABPI and the plethysmographically recorded leg blood flow at 55 years of age. A low pulse wave amplitude might reflect early symptom-free arteriosclerosis, or age-dependent non-arteriosclerotic loss of vessel wall elasticity. The relationship between a low pulse wave amplitude and a low ABPI remained when controlling for smoking, hypertension and hyperlipidaemia. It is concluded that pulse wave measurement by plethysmography contributes information to improve leg atherosclerotic risk assessment in individuals exposed to known risk factors.