Tall Tales of Diabetic Amputations

Diabetes is the leading cause of nontraumatic amputation in developed nations. Lower-limb amputations are particularly common in type 2 diabetes and impose a substantial burden on the patient’s and caregiver’s quality of life, as well as profound economic and health care burdens for the individual and society. Many studies have attempted to outline the risk factors for amputation, and institute modifications to mitigate the risks, but none have been very successful to date. Now, one diabetes researcher is claiming that one risk factor for amputation may not be modifiable at all: the taller the patient is, the higher the amputation risk.

The findings associating height and amputation risk come from a secondary analysis of the large Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study. One of the lead investigators presented the findings at the American Heart Association’s annual scientific sessions in Orlando. He reported that height was an independent risk factor for amputation during the 5 years that nearly 10,000 type 2 diabetic patients were followed. (During the study period, there were 190 amputations among 115 patients.) Further, every 10 centimeters of increased height corresponded to a 60% increased risk of lower-limb amputation.

This is not the first report that height may play a role in amputation outcomes. A large cross-sectional study of more than 93,000 patients with type 1 or type 2 diabetes in Taiwan concluded the same thing: greater height independently predicted lower-limb amputations. This makes some sense, as taller patients are at a greater risk for peripheral sensory loss than shorter patients, owing to the longer nerve fibers. This, in turn, places taller patients at risk for delayed treatment of diabetic foot and lower extremity ulcers and infections. Still, the association between height and amputation risk is not well-defined.

The FIELD study also found that, in addition to height, prior skin ulcers, previous amputations, neuropathy, peripheral vascular disease, and age were important predictors of amputation risk. Many large-scale, well-publicized studies have shown that many of these risk factors can be controlled through intense glucose control, especially when diagnosis is made and therapy is initiated early in the course of diabetes. However, other similarly large and well-respected studies showed that intense glucose control did not alleviate all of the micro- and macrovascular risks associated with diabetes. Still, all of the research instructs that patients should institute lifestyle modifications and medical treatment as soon as possible for the best chance of long-term positive outcomes.

Patients with chronic diseases like diabetes are bombarded with calls to modify their risk factors: stop smoking, lose weight, get more exercise, lower your cholesterol, or eat a healthier diet. Now, they are told that one significant predictor of serious outcomes is their height, something that is completely unmodifiable. While the researchers are proud to have found yet another group (tall people with diabetes) that need intense monitoring to promote early intervention and treatment, patients may be left wondering, “Is there anything I can really do?” No one can make him- or herself shorter, lifestyle modifications can only do so much, and everyone seems to fall in to one category or another that puts them at increased risk for something and calls for them to be at the front of the more-monitoring line. Maybe all anyone can really do is try to take care of the body he or she has been given and hope for the best.

References

Huysman E, Mathieu C. Diabetes and peripheral vascular disease. Acta Chir Belg. Oct 2009;109(5):587-594.

Tseng, C. (2006). Prevalence of lower-extremity amputation among patients with diabetes mellitus: Is height a factor? Canadian Medical Association Journal, 174 (3), 319-323 DOI: 10.1503/cmaj.050680

Rajamani, K., Colman, P., Li, L., Best, J., Voysey, M., D’Emden, M., Laakso, M., Baker, J., & Keech, A. (2009). Effect of fenofibrate on amputation events in people with type 2 diabetes mellitus (FIELD study): a prespecified analysis of a randomised controlled trial The Lancet, 373 (9677), 1780-1788 DOI: 10.1016/S0140-6736(09)60698-X

Rajamani K, Li LP, Kesaniemi YA, et al. Astract 1040: Lower-Limb Amputation in Patients With Type 2 Diabetes Mellitus: Factors Predicting Risk in the FIELD study. Circulation. November 2009;120:S431.