We performed a clinical and physiological study in diabetic patients with distal symmetrical sensory neuropathy in an attempt to correlate the extension of sensory loss with alterations of cardiocirculatory tests. These tests included measurement of blood pressure and heart rate in the recumbent and upright positions, Valsalva's manoeuvre and respiratory variations of R-R intervals. We thus studied 56 patients with distal sensory neuropathy. We found that all three tests were impaired in all patients with sensory loss above the knee level. We found a highly significant correlation between the level of sensory loss and impairment of physiological tests (p < 0.001). We conclude that both sensory loss above the knee and impairment of all three cardiocirculatory tests result from a severe neuropathy, but this correlation may not be sufficient to assert that cardiocirculatory impairment that occurs in diabetic neuropathy is a length dependent phenomenon.