Incidence of Diabetic Foot and Associated Risk Factors in Type 2 Diabetic Patients: A Five-year Observational Study

Background: The frequency of lower extremity amputation due to diabetic foot has been increasing in type 2 diabetic patients. The aim of this study was to observe the incidence, clinical aspects and associated risk factors for diabetic foot. Methods: We evaluated the incidence of diabetic foot through a five-year observation of type 2 diabetic patients who presented to St. vincent's Hospital between Januar y and December 2003. To identify the risk factors for diabetic foot, we evaluated mean glycosylated hemoglobin A1c (HbA1c) every six months and assessed renal function based on the existence of proteinuria and estimated glomerular filtration rate (GFR) using the Modification of Diet in Renal Disease (MDRD) equation. Patients were also evaluated for retinopathy, peripheral neuropathy and autonomic neuropathy usi ng Ewing's method. Results: From an initial pool of 613 patients, the observational study o f 508 patients (82.9%) was completed. The mean age, duration of diabetes and HbA1c were 50.3 ± 10.6 yrs, 7.2 ± 6.5 yrs and 8.8 ± 2.1%, respectively. Diabetic foot occurred in 32 patients (6.3%). The incidence of diabetic foot increased when diabetic retinopathy (OR = 6.707, 2.314~19.439), peripheral neuropathy (OR = 2.949, 1.075~8.090), and autonomic neuropathy (OR = 3.967, 1.476~10.660) were present and when the MDRD GFR (OR = 5.089, 1.712~15.130) decreased. Mean HbA1c (OR = 12.013, 1.470~98.179) was found to be an independent risk factor for diabetic foot. Conclusion: The present study confirmed the importance of intensive glycemic control and the role of autonomic dysfunction in the development of diabetic foot. In addition, diabetic retinopathy and impaired renal function proved to be factors associated with the occurrence of diabetic foot. Therefore, intensive glycemic control, as well as periodic examination of renal function, are essential for the prevention of diabetic foot. (Korean Diabetes J 33:315-323, 2009)