Relationship Between GFR And The Severity Of Diabetic Foot In Patients With Type 2 Diabetes Mellitus

ObjectiveDiabetes mellitus is a metabolic syndrome characterized by a chronic state of high blood sugar level. With the increasing prevalence of type 2 diabetes, its various complications have drawn more of people’s attention. Diabetic foot is one of the chronic complications of diabetes, and has become the leading cause of non-traumatic lower extremity amputations. About 80% of these patients have diabetic foot ulcers first. Diabetic nephropathy is also one of the chronic complications of diabetes, that is often accompanied by diabetic neuropathy and diabetic retinopathy, both of which are important factors related to the prognosis of diabetic foot. Kidney damage caused by diabetic nephropathy can increase the risk for diabetic foot ulcers, and diabetic patients with renal dysfunction is more likely to need low extremity amputations than average diabetic patients. This study aims to evaluate the relationship between renal functions and the severity of diabetic foot, using eGFR as an indicator.MethodsA total of 216 hospitalized patients with type 2 diabetic foot in Endocrinology Department from Qilu Hospital of Shandong University from 2010-01-01 to 2015-12-31 were analyzed. Their case files and relevant data were collected, including general information such as gender, age, weight, BMI, blood pressure and temperature; patients’history such as the course of T2DM, the cause, course, severity and progression of diabetic foot ulcers, treatment history of diabetic foot ulcers and other diseases; lab results such as fasting C peptide, HbAic, BUN, Cr, total protein, albumin, TG, LDL-C, HDL-C, white blood cell, neutrophile granulocyte, erythrocyte sedimentation rate, routine urine test; test results such as ultrasound of both legs, X ray of the affected foot; physical examinations information such as the color and temperature of the feet, the pulses of dorsalis pedis, foot abnormality, edema, tenderness, soft tissue infection or osteomyelitis, the appearance, location, range, temperature and smell of the ulcers. eGFR(ml/min per 1.73m2)= 186×Cr(mg/dl)-1154xAge(year)-0.203×0.742(if female)×1.233(if Chinese). Groups were divided according to Wagner classification as well as the severity of the vascular dysfunction. For descriptive statistical analysis, means and standard deviations were calculated, t-test was used to compare between two groups, One-way ANOVA was used to compared between multiple groups. Pearson test was used for the correlation test between two continuous variables, and Spearman test was used for the correlation test between a continuous variable and a categorical variable. Multiple stepwise regression was used to evaluate the relationship between eGFR and the severity of diabetic foot. P<0.05 was considered to be statistically significant.Results1. The levels of hemoglobin, albumin and eGFR were significantly different between Wagner groups. The eGFR of Wagner 2-5 group were significantly lower than that of Wagner 0 group(P<0.05), particularly Wagner 4+5 group with a P<0.01. The eGFR of Wagner 2 group and Wagner 4+5 group were also significantly lower than that of Wagner 1 group(P<0.05).2. The levels of age, HbA1C, HDL-C, hemoglobin, albumin and eGFR were significantly different between vascular groups. The eGFR of severe angiostenosis group and vascular occlusion group were significantly lower than that of arteriosclerosis group (P<0.01). T he eGFR of severe angiostenosis group and vascular occlusion group were also significantly lower than that of light angiostenosis group(P<0.05).3. eGFR was negatively correlated with Wagner classification(r=-0.471, P=0.000). eGFR was negatively correlated with the severity of vascular lesions of lower extremity(r=-0.453, P=0.000).4. Multiple stepwise regression showed that eGFR was closely related with Wagner classification and the severity of vascular lesions of lower extremity and eGFR was their independent influencing factor.Conclusion1. In type 2 diabetic foot patients, the lower the eGFR, the more severe the diabetic foot condition was, regardless of whether it was measured by Wagner classification or vascular conditions.2. eGFR had a drastic decrease at Wagner 2 or severe angiostenosis level, indicating a clinical intervention might be in order at this stage.3. eGFR was an independent influencing factor for Wagner classification and the severity of vascular lesions of lower extremity and can be helpful in evaluating the severity of diabetic foot. Clinical practitioners should pay more attention to the renal functions of diabetic foot patients. This may help to prevent the progression of diabetic foot.