Various factors are associated with foot ulceration, including delayed reporting of ulcers, poor glycemic control, and severity of neuropathy. Several studies have looked at the role of nitric oxide in wound healing. However, no studies have examined its role in the occurrence and recurrence of diabetic foot ulceration. In a cross-sectional study we examined the role of neuropathy, retinopathy, nephropathy, and plasma nitric oxide (estimated from plasma nitrite and nitrate) levels in diabetic patients with recurrent and non-recurrent neuropathic and neuroischemic foot ulcers. Patients with recurrent foot ulcers had higher vibration perception threshold values compared to patients with non-recurrent foot ulcers (47.4 +/- 5.7 volts versus 39.5 +/- 10.3 volts respectively, P