Risk Factors for Non‐ischaemic Foot Ulceration in Diabetic Nephropathy

It is recognized that diabetic patients with nephropathy frequently have macrovascular disease leaving them at risk of ischaemic foot lesions. In order to assess non‐vascular risk factors for foot ulceration 64 patients were stratified into four groups: microalbuminuria, albuminuria with creatinine clearance > 40 ml min−1, chronic renal failure (clearance < 40 ml min−1), and a non‐nephropathic diabetic control group. Vibration perception threshold was measured by biothesiometry, peroneal nerve conduction velocity by conventional methods, and dynamic foot pressure by pedobarography. Vibration perception threshold was elevated in all three groups when compared with age‐matched normal and diabetic control groups. Mean vibration perception threshold was 20.8 ± 8.6 (±SD) in the microalbuminuria group (p < 0.001 compared with age‐matched normal control group), 28.1 ± 5.6 (p < 0.001) in the albuminuria group, 38.9 ± 9.4 (p < 0.001) in the renal failure group, 14.8 ± 5.2 in the diabetic control group and 12.3 ± 2.9 in the normal control group. Peroneal motor conduction velocity was reduced in all three groups when compared with normal control subjects, microalbuminuria 38.6 ± 4.2 m s−1 (p < 0.001), albuminuria 38.0 ± 6.1 m s−1 (p < 0.01), renal failure 35.5 ± 1.2 m s−1 (p < 0.001), diabetic control 40.6 ± 1.8 m s−1, and normal 43.1 ± 2.3 m s−1. Mean peak plantar foot pressure was elevated in all three groups when compared with age‐matched normal anddiabetic control groups (p < 0.01), microalbu‐minuria 12.2 ± 3.1 kg cm−2, albuminuria 14.1 ± 2.6 kg cm−2, renal failure 15.2 ± 4.3 kg cm−2, diabetic control 11.4 ± 4.1 kg cm−2, and normal 8.2 ± 2.7 kg cm−2. A previous history of foot ulceration was recorded in 5 % of the diabetic control group, 10 % of patients with microalbuminuria and albuminuria, and 40 % with renal failure. We conclude that patients at all stages of diabetic nephropathy are at increased risk of non‐vascular foot ulceration.