Leg Symptoms in Peripheral Arterial Disease
Abstract & Commentary
Synopsis: Patients with peripheral artery disease have a wide range of symptoms beyond those of intermittent claudication. Comorbid conditions may contribute to these nonclassical symptoms.
Source: McDermott MM, et al. JAMA. 2001;286:1599-1606.
Intermittent claudication (IC) is the classic manifestation of peripheral artery disease (PAD). However, if the ankle brachial index (ABI) is used as a criteria to diagnose PAD, many individuals report no symptoms or symptoms other than IC. In this study, McDermott and associates examined the spectrum of functional limitations associated with different symptom categories of patients with PAD.
The study group consisted of 460 individuals with PAD and 160 without PAD. The standard for diagnosing PAD was an ABI < 0.9. Outcome measurements included scores from a 6-minute walk, repeated chair raises, standing balance, 4-m walking velocity and scores on claudication, depression and walking impairment questionnaires. PAD patients were classified into 6 groups: leg pain with rest and exertion, IC alone, atypical exertion leg pain but requiring the patient to stop, atypical leg pain that the patient walks through, and those with no exertional leg pain divided into those who are active vs. those who are inactive.
All groups with PAD had poorer functioning measures than those without PAD. Those with IC and rest pain were more likely to have spinal stenosis, neuropathy, and diabetes than the atypical leg pain group. The atypical pain group had better overall functioning than the IC group and achieved a greater distance in the 6-minute walk.
McDermott et al conclude that there is a wide range of symptoms and impairment for individuals with PAD beyond that of classic IC. The level of comorbid disease may contribute to the diversity of symptoms.
Comment by Martin Lipsky, MD
I have the pleasure of knowing Dr. McDermott as a colleague at Northwestern University Medical School. It is through her work and others that I have gotten an appreciation for the prevalence of PAD in a primary care setting. The findings reported in this study add to the growing literature about the importance and use of measuring an ABI in individuals with suspected PAD. In addition to being an important marker for CAD, the study suggests that even in the absence of IC, PAD can cause a wide range of symptoms and significantly impair an individual’s level of function. I will consider PAD for patients with vague leg symptoms that I may have mistakenly labeled as "arthritis." The findings also suggest that because of the high levels of comorbid diseases in patients with PAD, clinicians should consider the possibility that conditions such as spinal stenosis and neuropathy may contribute to the functional impairment. Addressing comorbid conditions should be an important part of managing these patients.
Dr. Lipsky, Professor and Chair, Department of Family Medicine, Northwestern University Medical School, Chicago, IL, is Associate Editor of Internal Medicine Alert.