Impact of microvascular complications on the outcomes of diabetic foot in type 2 diabetic patients with documented peripheral artery disease

Purpose: Microvascular disease (MVD) is associated with amputation linked to peripheral artery disease (PAD) in the general population. No study evaluated the impact of diabetic microvascular complications on the outcomes of vascular diabetic foot ulcers (DFU). The aim of the study was to investigate whether retinopathy, nephropathy, and polyneuropathy can predict the outcomes of DFU in type 2 diabetic patients with PAD. Methods: Three hundred and thirty-one consecutive patients with vascular DFU were enrolled and followed up for 44.1 ± 23.9 months. Results: The prevalence of retinopathy was significantly higher in subjects with ulcer persistence (45.2%; p < 0.01), minor amputation (48.9%; p < 0.001), and major amputation (57.9%; p < 0.001) than in healed patients (23.3%), and in non-survivors than in survivors (64.9 versus 20.5%; p < 0.001). The prevalence of nephropathy was significantly greater in subjects with ulcer persistence (83.9%; p < 0.01), minor amputation (86.7%; p < 0.001), and major amputation (94.7%; p < 0.001) than in those with healed DFU (64.4%), and in non-survivors than in survivors (88.3 versus 65.7%; p < 0.001). The prevalence of polyneuropathy was significantly higher in non-survivors than in survivors (76.6 versus 61.0%; p = 0.012). Multivariate analysis showed that absence of retinopathy (OR: 0.451; 95% CI: 0.250-0.815; p < 0.001) and nephropathy (OR: 0.450; 95% CI: 0.212-0.951; p = 0.036) were independently associated with healing. Moreover, retinopathy was a predictor both of minor amputation (OR: 2.291; 95% CI: 1.061-4.949; p = 0.034) and mortality (OR: 5.274; 95% CI: 2.524-11.020; p < 0.001). Polyneuropathy never entered the regression model. Conclusions: Diabetic microvascular complications, in particular retinopathy, may predict the outcomes of vascular DFU. Longitudinal studies should confirm this finding.