NEW YORK (Reuters Health) – New research indicates that insulin-using diabetics with chronic limb ischemia have worse limb salvage rates and survival than their nondiabetic peers or diabetics who control their disease with diet or oral medications alone.
“The significant findings of our study was that, indeed, the patency, limb salvage, and survival rates of patients whose diabetes are controlled with oral medications are exactly the same as non-diabetics,” lead author Dr. Hasan H. Dosluoglu told Reuters Health. “Both these groups fared significantly better than those needing insulin.”
The take home message, he added, “is that the patients with diabetes are not a uniform group of patients, and that any comparison between them and the non-diabetics should be made with caution, paying attention to the severity of disease in the study groups.”
Dr. Dosluoglu, from the State University of New York at Buffalo, presented his team’s findings Saturday at the 63rd Annual Meeting of the Society for Vascular Surgery.
The study included 746 patients (886 affected limbs) who presented with disabling claudication or critical limb ischemia between June 2001 and September 2008. Roughly half of the affected limbs were in diabetics.
Gangrene and foot sepsis were found in roughly 48% and 5%, respectively, of diabetic patients who used insulin. By contrast, corresponding rates in non-diabetics and non-insulin-using diabetics did not exceed 25% and 1%.
A primary amputation rate of 9% or higher was seen in insulin-using diabetics, compared with a 4% rate in non-diabetics and in non-insulin-using diabetics.
At 36 months, the survival rates for diabetics using insulin alone or with oral medications were 40% and 43%, respectively. The rates for non-diabetics and non-insulin-using diabetics were much higher, 72% and 71%, respectively (p < 0.001). In insulin-using diabetics, the limb salvage rate did not exceed 77%, much lower than the 91% rate seen in non-diabetics and in non-insulin-using diabetics (p < 0.001). With endovascular treatment, primary patency rates were lower in insulin-using diabetics than in other patients. With open revascularization, by contrast, no significant difference in patency was noted between the groups. “Although some studies have suggested that insulin use itself may be associated with worse outcomes, others have suggested that it is not the insulin itself, but it is more of a marker of the severity of diabetes,” Dr. Dosluoglu commented. Further research is needed to clarify the underlying mechanism, which could have important treatment implications.