Peripheral Arterial Disease – Risk and Outlook

There have been two recent items of news about peripheral arterial disease, or PAD. First, PAD may possibly be related to a relative lack of vitamin D. A report in Arteriosclerosis, Thrombosis, and Vascular Biology from Mount Sinai School of Medicine, New York, examines the association between blood vitamin D levels and the frequency of PAD. Almost 5,000participants over 40 had their vitamin D levels and their ankle:arm blood pressure ratios measured; A ratio of less than 0.9 was considered diagnostic for PAD. The subjects were classified into four groups (quartiles), according to their vitamin D levels. The frequency of PAD was 8.1%, 5.4%, 4.9%, and 3.7% for the highest to lowest vitamin D groups. This suggests, but doesn’t prove, that a low vitamin D level may accelerate or promote the atherosclerosis process. For proof, a large well-designed prospective study would be needed. So don’t take vitamin D supplements on the basis of this study alone!

Second, PAD carries a worse outlook than heart disease. A report in the Journal of the American College of Cardiology compared the mortality in PAD with that in coronary artery disease (CAD). It should be remembered that the basic pathological process is extremely similar for both conditions – atherosclerosis.

Survival in 2,730 PAD patients having vascular surgery was compared with the same number of CAD patients having coronary angioplasty. The PAD surgery was on the carotid artery (560), abdominal aorta (1,123), or a leg artery (1,047). The annual mortality rates were 5.7% in PAD patients, and 3.0% in CAD patients – a statistically significant difference. The authors of the study showed that PAD patients were less likely to be given cardiac medications (e.g. beta-blockers, calcium antagonists, aspirin, or statins) and that the majority of deaths in both PAD and CAD were cerebro-cardiovascular (i.e. heart attack, heart failure, stroke, etc). They offer undertreatment of the basic arterial condition in PAD as the explanation for the difference in mortality rates.