Walid Alami, MD, FACC, FSCAL
Peripheral arterial disease (PAD) is a common cardiovascular disorder caused by atherosclerotic obstruction of the abdominal aorta and arteries to the legs that reduces blood flow during rest and/or exercise. It has been well established that diabetics with PAD, don’t fare as well as with those without diabetes.
PAD occurs in approximately 1/3 of patients above the age of 70, and in 1/3 of patients above the age of 50 with a history of tobacco abuse or diabetes mellitus (DM). It is a progressive disease and failure of early detection and/or appropriate treatment can lead to impaired quality of life, limb loss and premature mortality. The relative 5-year mortality rate in patients with PAD is higher than that of disorders such as colorectal and breast cancer.
RISK FACTORS: The major contributing risk factors for developing PAD are similar to those leading to coronary and cerebrovascular disease, including: advanced age, tobacco abuse, DM, dyslipidemia, hypertension and obesity. After smoking, DM is the most important risk factor for the development and progression of PAD. Given an aging population, changes in diet and lifestyle and rising obesity rates, DM is becoming an epidemic in our societies.
PAD is 5 times more common in diabetic patients, and 30 percent of diabetics have documented PAD. Major limb amputation is 4 times higher in the diabetic versus a non-diabetic patient.
The prevalence of PAD in diabetics is higher (22.4 percent), than those with impaired glucose (19.9 percent) and those with normal glucose tolerance (12.5 percent). It is interesting to note that each 1 percent increase in hemoglobin A1C increases the risk of PAD by 28 percent. Conversely, reducing hemoglobin A1C leads to a reduction in the amputation rate.
THE DIABETIC FOOT: Every year, more than one million people with DM lose a leg. This means that every 30 seconds, a lower limb is lost to DM/PAD worldwide. Most of these amputations are preceded by a foot ulcer, mostly due to foot deformity or minor foot trauma. Once an ulcer develops, the combination of infection and PAD may impair it from healing and may lead to an amputation if not treated appropriately in a timely manner.
One in six people with DM will have a foot ulcer in their lifetime and at least 1/4 will not heal resulting in amputation.
TREATMENT: Patient education, raising awareness among the public and the medical practitioners is key. Proper physical examination and screening is essential. Treatment should focus on:
1- Lifestyle changes in the diabetic patient to include a diabetic diet, weight loss if indicated and increased activity
2- Risk factor modifications and appropriate pharmacological treatments
3- Anti-platelet treatment
4- Appropriate surgical or endovascular intervention
5- Follow up with a wound care specialist
CONCLUSION: The combination of DM/ PAD is ominous. The key principles of PAD treatment in the diabetic aim at improving clinical signs and prevention of cardiovascular mortality/morbidity and amputations. Investing in diabetic foot care guidelines is therefore one of the most cost effective strategies.
Unfortunately, PAD remains a vastly under diagnosed illness and shockingly a minority of patients undergo noninvasive or invasive screening. Although endovascular intervention is becoming the dominant approach for treatment of such patients, only 4 percent of patients are being treated.
Lack of public awareness remains an obstacle, especially in the underdeveloped countries. It is thus, the duty of the practitioner to educate the public and act promptly before it is too late.
Just like the saying TIME IS MUSCLE in the setting of an acute myocardial infarction, so is TIME IS TISSUE in the setting of critical limb ischemia.