Epidemiology of diabetic foot problems and predictive factors for limb loss

Abstract

Objectives: The aim of this study was to evaluate the epidemiology of diabetic foot problems (DFP) and predictive factors for major amputations (below- and above-knee).

Methods: This is a prospective study of 202 patients treated in National University Hospital (NUH) during the period of January 2005 to May 2006. A protocol was designed for documentation including patient profile, type of DFP, presence of risk factors, comorbidities and complications, clinical presentation, investigations, treatment given, and final outcome. The predictors for limb loss were determined using univariate and stepwise logistic regression analysis.

Results: One hundred ninety-two patients had Type 2 diabetes. Mean age of cohort was 60 years, with male to female ratio of 1:1. Incidence of DFP was significantly higher in Malays (P=.0015) and Indians (P=.036) and significantly lower in Chinese (P<.05). Of patients, 72.8% had poor endocrine control (GHb level >7%), and 42.1% of patients had sensory neuropathy based on 5.07 Semmes-Weinstein Monofilament test. Common DFP included gangrene (31.7%), infection (abscess, osteomyelitis) (28.7%), ulcer (27.7%), cellulitis (6.4%), necrotizing fasciitis (3.5%) and Charcot's osteoarthropathy (2.0%). Surgery was performed in 74.8% of patients and major amputation in 27.2% of patients (below-knee in 20.3% and above-knee in 6.9%).

Conclusions: This is the first detailed prospective study evaluating predictive factors for major amputations in patients with DFP. Significant univariate predictive factors for limb loss were age above 60 years, stroke, ischaemic heart disease, nephropathy, peripheral vascular disease (PVD), sensory neuropathy, glycosylated haemoglobin level, Ankle Brachial Index (ABI) <0.8, gangrene, infection, and pathogens such as methicillin-resistant Streptococcus aureus (MRSA) and Staphylococcus aereus. Upon stepwise logistic regression analysis, only PVD and infection were significant.