Autonomic neuropathy in non-insulin-dependent diabetic patients: correlation with age, sex, duration and metabolic control of diabetes.

The aim of this study has been to assess the prevalence of autonomic neuropathy among non-insulin dependent diabetic patients, and to determine whether a correlation could be found between autonomic impairment and the following: age, sex, duration of diabetes, body mass and metabolic control. Two hundred and twenty one non-insulin dependent patients were submitted to four cardiovascular tests: heart rate response to deep breathing and to standing up; blood pressure response to handgrip and to standing up. Sixty six percent of patients showed at least one abnormal cardiovascular response. The prevalence of autonomic impairment was higher in non-insulin dependent than in insulin-dependent diabetics. Patients were grouped according to the extent of autonomic impairment: absent (33.5%), early (27.6%), definite (3.6%), severe (4.5%). An atypical pattern (abnormality of blood pressure responses in absence of a definite abnormality of heart rate responses) was found in 30.8% of patients. Heart rate responses correlated significantly with age (p less than 0.001). No correlation between test results and duration was found in the multivariate analysis. The tests' results did not correlate with metabolic control or body mass index. Patients with symptoms of autonomic neuropathy had values for heart rate response to deep breathing and to standing significantly lower than those without (p less than 0.05).