Changes in autonomic nervous function over a 5-year period in non-insulin-dependent diabetic patients.

One hundred and eight non-insulin-dependent diabetic patients who had been tested for autonomic dysfunction in 1984/85 were re-evaluated 5 years later. Autonomic function was assessed by means of four cardiovascular tests (heart rate variation during deep breathing and standing, and blood pressure variation after standing and sustained handgrip). Eighteen subjects were lost to follow-up; in the 90 patients who completed the study, both the deep breathing and the handgrip test significantly worsened (respectively from 13.7 +/- 7.8 to 11.6 +/- 6.3 beats min-1 p < 0.01, and from 16.9 +/- 8.2 to 12.7 +/- 7.1 mmHg, p < 0.001), whereas both the 30:15 ratio and the variation of blood pressure on standing did not change. The impairment of a comprehensive evaluation score (from 2.5 +/- 1.7 to 3.0 +/- 1.5; p < 0.05) also confirmed the gradual deterioration of autonomic function over the study period.