AUTONOMIC DYSFUNCTION IN VITAMIN-B12 DEFICIENCY - A HEART-RATE-VARIABILITY STUDY

This study was arranged to examine whether vitamin B12 deficiency may cause autonomic dysfunction. Time-domain and long-term frequency-domai n heart rate variability parameters from 12 patients with pernicious a nemia were compared to 12 age and sex matched controls. In B12 deficie nt patient group time-domain parameters; SDNN (100.4 +/- 37.86 vs. 131 .91 +/- 26.94, P = 0.05), SDANN (87.00 +/- 37.77 vs. 118.83 +/- 26.22, P = 0.05) SD (39.41 +/- 13.32 vs. 53.41 +/- 15.39, P = 0.0221), rMSSD (21.41 +/- 10.00 vs. 28.5 +/- 8.42, P = 0.046) were significantly low er when compared to controls. Difference in pNN50 between groups were not statistically significant. In B12 deficient patients frequency-dom ain parameters; total power (23.08 +/- 9.89 vs. 34.75 +/- 9.56, P = 0. 0078), low frequency power (13.5 +/- 6.57 vs. 22.75 +/- 7.25, P = 0.00 69) and high frequency power (7.58 +/- 4.25 vs. 11.58 +/- 3.80, P = 0. 0175) were significantly lower when compared to controls. It was concl uded that B12 deficiency may cause autonomic dysfunction. (C) 1998 Els evier Science B.V. All rights reserved.