RESUMO
BACKGROUND: Autonomic dysfunction, an early manifestation of diabetic neuropathy, presents with altered sweating patterns, leading to dryness and fissuring. We conducted a study to assess the sweat function in the diabetic foot and to determine the interrelation between the duration of diabetes, sensation, fissuring, and sweating. METHODS: The sweat function was assessed in 30 diabetic patients, 28 of whom had fissuring of the feet, using Ninhydrin impregnated discs. RESULTS: There was a significant association between fissuring and sensation, but not between the duration of diabetes and fissuring and between loss of sweating and fissuring. In 18 patients (60%) there was impairment or absence of sweating in the presence of normal sensation. CONCLUSION: Although fissuring increases with long-standing diabetes and sweating is reduced in diabetic patients with fissures on the foot, the correlation between these entities was not statistically significant. Since 60% patients had altered sweating in the presence of normal sensations, the sweat test can be used as an early indicator of diabetic neuropathy.