Influence of foot ulceration on cause-specific mortality in patients with diabetes mellitus.

Abstract

The purpose of this study was to assess the odds of all-cause mortality in individuals with diabetic foot ulceration (DFU) compared with those with diabetes and no history of DFU. In addition, we sought to determine the strength of association of DFU with cardiovascular and nonvascular mortality. We obtained data for a cohort of patients who attended a secondary care diabetic foot clinic or a general diabetes clinic between 2009 and 2010. A clinic cohort of patients with diabetes and no history of DFU provided a control group. Cause-specific mortality was recorded during a median follow-up duration of 3.6 years (interquartile range, 3.3-4.2 years). The association between DFU and all-cause mortality was evaluated by Cox regression. The association between DFU and cardiovascular mortality was determined by competing risk modeling. We recorded 145 events of all-cause mortality and 27 events of cardiovascular mortality among 869 patients with diabetes. After adjustment for potential confounders, DFU was associated with both cardiovascular disease (hazard ratio, 2.53; 95% confidence interval, 0.98-6.49; P = .05) and all-cause mortality (hazard ratio, 3.98; 95% confidence interval, 2.55-6.21; P < .001). The proportion of deaths attributable to cardiovascular disease was similar between the groups (18% with diabetes only and 19% with DFU; P = .91). DFU is associated with premature death from vascular and nonvascular causes.