The Diabetic Foot as a Proxy for Cardiovascular Events and Mortality Review

Isa Dietrich, Gustavo Arruda Braga, Fernanda Gomes de Melo, Ana Carolina Calmon da Costa Silva Silva

This article reviewed very recent papers (2016) discussing or bringing clinical evidences of the possible common pathways leading to diabetic foot syndrome (DFS) and increased mortality rates. Diabetic patients with diabetic foot syndrome have a mortality rate greater than twofold when compared with non-ulcerated diabetics. In addition, the 5-year mortality rate following amputation is estimated at 39-68%, a life expectancy comparable to aggressive types of cancer or advanced congestive heart failure. The majority of patients with diabetic foot ulcer also present insulin resistance, central obesity, dyslipidemia, and hypertension that characterize the metabolic syndrome that, in turn, is associated with an elevated risk of major cardiovascular events. Sensory neuropathy is the primary cause of more the 60% of diabetic foot ulcer. Diabetic peripheral neuropathy is a microvascular complication of diabetes mellitus and in type 2 diabetes, not only hyperglycemia but also other metabolic alterations and persistent inflammatory status due to adiposity play a major role in axon injury. Elevated triglycerides have been showed to be an independent risk factor for lower extremity amputation in diabetic patients. Also, toxic adiposity, oxidative stress, mitochondrial dysfunction, activation of the polyol pathway, accumulation of advanced glycation end products (AGEs), and elevation of inflammatory markers are also implicated in diabetic vascular disease and neuropathy. The hypotheses that the association between DFS and increased rates of mortality reflects the progression of micro- and macrovascular complications are reinforced by the additional association of DFU to renal failure and retinopathy.