Risk Factors for Developing Diabetic Foot Ulcer with Nephropathy, Diabetic Kidney Disease and Renal Failure Statistical Analysis of 10,680 Patients’ Cohort

Abstract

ABSTRACTIt has been cited in the research that patients with diabetic kidney disease (DKD) and foot ulcer have poor prognosis; and foot ulceration is associated with kidney dysfunction. However, no study have found association of diabetic foot ulcer (DFU) with diabetic kidney dysfunction and their co-existing risk factors including blood pressure, serum creatinine, microalbumin, spot urine protein, HbA1c and associations of nephropathy and DKD with low ankle brachial index (ABI). We monitored, collected and analyzed the data for 10,680 patients for a duration of more than 13 years. 12% of patients demonstrated DFU. Nephropathy was observed in 39% of patients; 43% was hypertensive while 15% demonstrated DKD or CKD. Levels of HbA1c, creatinine,, systolic and diastolic blood pressures, microalbuminuria, spot urine protein, and spot urine protein to creatinine ratio were higher among the groups with foot ulcers (p-value < 0.0001 for all). Average ABI was observed to be lower among the groups demonstrating nephropathy and DKD with significant p-values (p=0.025 and 0.022 respectively). Pearson’s χ2 and logistic regression with odds ratio were also analyzed for DFU with HTN, nephropathy and DKD. DFU was significantly associated with HTN (odds ratio 2.2 ; 95% CI 1.66 to 2.9; p < 0.0001), nephropathy (odds ratio 4.77 ;95% CI 3.53 to 6.5; p < 0.0001) and DKD (odds ratio 4.77 and 6.83; 95% CI 4.6 to 10.2; p < 0.0001). ROC was used to find out cutoff values, sensitivity and specificity. HbA1c of 7.8% was 60% sensitive and 52% specific for the development of DFU (AUC = 0.58; 95% CI 0.521 to 0.624; p < 0.0006). Creatinine of 1.2 mg/dl was 75% sensitive and 48% specific for DFU (AUC = 0.58; 95% CI 0.640 to 0.715; p < 0.0001). Spot urine protein excretion from nephrons of 35 mg/dl was 88% sensitive and 90% specific for the development of DFU (AUC = 0.585; 95% CI 0.555 to 0.616; p < 0.0001). Our data has demonstrated the first time such associations and confirmed that nephropathy or renal failure are risk factors for the development of DFU. HbA1c should be optimal and near to the targets to improve wound healing. Our study has prompted diabetologists for regular and routine assessment of the feet and early screening of diabetic patients for neuropathy, nephropathy, hypertension, dyslipidemia and other diabetic complications as well.