Asymptomatic arteriopathy of the lower limbs. Prevalence and risk factors in a population of southern Italy

Peripheral vascular diseases, both symptomatic and asymptomatic, are strong predictors of total and cardiovascular mortality. The commonly used Rose questionnaire, although highly specific, has a low sensitivity to detecting peripheral vascular disease and is not adequate for asymptomatic subjects. Doppler ultrasound measurement of the ankle/brachial systolic blood pressure ratio is a non-invasive, reproducible and accurate method of assessment of peripheral vascular disease and has been validated by angiography. METHODS. Five hundred and ten subjects, corresponding to fifty percent of the people working as civil servants in the Catanzaro city hall, were invited to join the study by a letter. Three hundred and eighty four participated. Exclusion criterion was claudicatio intermittens as detected by Rose questionnaire. All the subjects filled a questionnaire to assess coronary heart disease risk factors and underwent a full clinical examination. Brachial blood pressure was measured on both arms with participants in supine position, just before ECG. The systolic ankle blood pressure was measured with ultrasonic technique. The blood pressure cuff was placed just proximal to the medial malleolus. The ankle-brachial systolic pressure index (Winsor Index) was determined by dividing the highest of the posterior tibial or dorsalis pedis pressures by the highest brachial pressure. A limit of 0.95 was chosen to identify subjects with peripheral arterial disease. Venous blood for serum cholesterol and triglycerides, apolipoprotein AI and B and blood glucose, was collected after an overnight fasting, into Vacutainer Tubes (Becton & Dickinson). RESULTS. No subject had claudicatio intermittens. Sixteen subjects were excluded from the statistical analysis because of missing data. Two hundred and sixty-three were males and 105 females. Twenty-one (5.7%) out of 368 participants had a Winsor Index < 0.95 in at least one leg. These subjects had higher values of systolic and diastolic blood pressure compared to normal subjects whereas no differences were observed with regard to age, BMI, lipid profile and blood glucose. Furthermore the prevalence of hypertension was higher in the group of subjects with asymptomatic peripheral arterial disease. The prevalence of other risk factors for atherosclerosis (cigarette smoking, hyperlipidemia, diabetes mellitus, obesity) was similar in subjects with or without peripheral arterial disease. DISCUSSION. In the present study the prevalence of Winsor Index < 0.95 was 5.7%, similar to that reported by other authors. Hypertension was the only risk factor for atherosclerosis associated with peripheral arterial disease. Other authors also reported a higher prevalence of cigarette smoking among subjects with peripheral disease. In our population this association was not found but the participants were younger and consequently the exposure to this risk factor was shorter. CONCLUSION. The measurement of systolic ankle blood pressure by Doppler ultrasounds is a non-invasive, well accepted, highly specific and sensitive method to detect asymptomatic peripheral arterial disease. It might be of value in better defining the cardiovascular risk profile both in epidemiologic studies and clinical practice, especially in subjects with hypertension.