A study published online July 22 in Diabetes Care has concluded that individuals with diabetes who have undergone a lower-limb amputation are more likely to die, with some of the increased risk due to diabetes-related complications.
A team of researchers from the University of Pennsylvania Perelman School of Medicine conducted a longitudinal cohort study of patients cared for in the Health Improvement Network. The goal of the research was to determine whether complications of diabetes that are well known to be associated with death, such as cardiovascular disease and renal failure, fully explain the higher rate of death in those who have undergone a lower-limb amputation.
The researchers found that the hazard ratio (HR) for death after a lower-limb amputation was 3.02. After adjusted for all risk factors, the lower-limb amputation HR was diminished only by about 22 percent to 2.37. Furthermore, lower-limb amputation had an area under the receiver operating curve (AUC) of 0.51, which is poorly predictive, and the fully adjusted model had an AUC of 0.77, which is better but not strongly predictive. Sensitivity analysis revealed that it is unlikely that there exists an unmeasured confounder that can fully explain the association of lower-limb amputation with death.
“Individuals with diabetes and…[a lower-limb amputation] are more likely to die at any given point in time than those who have diabetes but no…[lower-limb amputation]. While some of this variation can be explained by known complications of diabetes, there remains a large amount of unexplained variation,” the study concludes.