Painful Diabetic Neuropathy
Advantage of novel drugs over old drugs?
- Dan Ziegler, MD, FRCP(E)
- From the Institute for Clinical Diabetology, German Diabetes Center at the Heinrich-Heine University, Leibniz Center for Diabetes Research, and the Department of Metabolic Diseases, University Hospital, Düsseldorf, Germany.
- Corresponding author: Dan Ziegler, dan.ziegler{at}ddz.uni-duesseldorf.de.
Neuropathic pain exerts a substantial impact on quality of life, particularly by causing considerable interference in sleep, daily activities, and enjoyment of life. Chronic neuropathic pain is present in 13–26% of diabetic patients (1–4). In a recent survey from Augsburg, Germany, the prevalence of painful polyneuropathy was found to be 13.3% in diabetic subjects, 8.7% in individuals with impaired glucose tolerance, 4.2% in individuals with impaired fasting glucose, and 1.2% in individuals with normal glucose tolerance (3). Independent factors significantly associated with diabetic painful neuropathy (DPN) were age, weight, and peripheral arterial disease. Pain is a subjective symptom of major clinical importance, since it is often this complaint that motivates patients to seek health care. However, in a survey from the U.K., only 65% of diabetic patients received treatment for their neuropathic pain, although 96% had reported the pain to their physician. Pain treatment consisted of antidepressants in 43.5% of cases, anticonvulsants in 17.4%, opiates in 39%, and alternative treatments in 30% (combinations possible). Whereas 77% of the patients reported persistent pain over 5 years, 23% were pain free over at least 1 year (1). Thus, neuropathic pain persists in the majority of diabetic patients over periods of several years.
MANIFESTATIONS OF PAINFUL NEUROPATHY
Chronic DPN with persistent or episodic pain that typically may worsen at night, and improve during walking, is localized predominantly in the feet. The pain is often described as a deep-seated ache, but there may be superimposed lancination, or it may be of burning thermal quality. In a clinical survey including 105 patients with DPN, the following locations of pain were most frequent: 96% feet, 69% balls of feet, 67% toes, 54% dorsum of foot, 39% hands, 37% plantum of foot, 37% calves, and 32% heels. The pain was most often described by the patients as “burning/hot,” “electric,” …
