To test the natural progression of symptoms of autonomic neuropathy (AN) and function tests in subjects with IDDM.
Seventy-six subjects with IDDM of < 10 years duration had cardiovascular autonomic reflex tests and were evaluated for signs and symptoms of AN.
Fifty-seven subjects (66%) were available for restudy 9 years later (15 had died, 4 could not be located). Of the symptoms of AN, only gastroparesis increased in prevalence (P < 0.01). Of the five cardiovascular AN measures, only the R-R response to the Valsalva maneuver deteriorated (F[1,44] = 10.61, P < 0.01).
The progression of AN in IDDM is monitored best longitudinally by the Valsalva maneuver because of the small variance ratio in repeated measures. Prevalence rates can be monitored by expiration-to-inspiration R-R or Valsalva ratios. Most clinical signs and symptoms of AN do not progress, underscoring the need for objective and quantitative autonomic function tests to identify people at risk for premature death.