Diabetes Care, Vol 10, Issue 6 735-741, Copyright © 1987 by American Diabetes Association
Sensitivity of R-R variation and Valsalva ratio in assessment of cardiovascular diabetic autonomic neuropathy
AH Rothschild, CR Weinberg, JB Halter, D Porte and MA Pfeifer
Department of Medicine, University of Louisville, Kentucky.
R-R variation and the Valsalva ratio are commonly used to quantitatively
assess diabetic autonomic neuropathy (DAN). To assess the sensitivity of
these two measures to parasympathetic ablation, 12 nondiabetic subjects
were tested before and after graded doses (0.3-4.0 mg i.v.) of atropine.
R-R variation was significantly reduced at 0.7 mg, whereas Valsalva ratio
was not significantly smaller until the 2.0-mg dose of atropine. R-R
variation continued to become progressively smaller during the 0.85-, 1.0-,
and 2.0-mg doses. Valsalva ratio, but not R-R variation, was further
reduced by the 4.0-mg dose. To further compare these two measures, two
groups of diabetic subjects were compared with a group of nondiabetic
subjects (n = 22). One group of diabetic subjects had symptoms of DAN (n =
22), and the other diabetic group had no symptoms of DAN (n = 19). In DAN
subjects, both R-R variation (nondiabetic 33.2 +/- 4.3 vs. DAN 9.8 +/- 1.2,
P less than .001) and the Valsalva ratio (nondiabetic 1.98 +/- 0.07 vs. DAN
1.55 +/- 0.07, P less than .001) were reduced. However, in asymptomatic
subjects, R-R variation (23.2 +/- 3.9, P less than .05), but not Valsalva
ratio (1.94 +/- 0.13, NS), was less than nondiabetic subjects. Even after
beta-blockade, R-R variation was still less in both groups of diabetic
subjects (nondiabetic 34.4 +/- 4.2 vs. DAN 7.4 +/- 1.3, P less than .001;
asymptomatic 21.8 +/- 3.3, P less than .02).(ABSTRACT TRUNCATED AT 250
WORDS)