Estimation of the cut-off value in cardiovascular autonomic nervous function tests: not-age-related criteria or the age-related 5th percentile.
The aim of the study was to estimate the cut-off value of cardiovascular tests using not-age-related criteria or the age-related 5th percentile in 165 diabetic patients. The cANP, pANP, and smNP were assessed using previously recommended standardized test procedures. Prevalence of overall definite (borderline) cANP was 35.2% (23.0%) when using the 5th percentile or 16.4% (27.9%) when using not age-related criteria (p for the difference < 0.0001) (p = 0.3205). Prevalence of pANP was 54.0% and of smNP 37.0%. Concerning cANP, the number of test results below the 5th percentile (N5) correlated significantly with the number of abnormal test results using not age-related criteria (Nnar) (p < 0.000001) but the slope of the regression line differed substantially from 1. Using the 5th percentile as the cut-off value for cANP testing, sensitivity and specificity were calculated for not age-related criteria for respiratory sinus arrhythmia (90.5%, 80.2%), Valsalva test (30.4%, 98.0%), lying-to-standing test (46.3%, 98.7%), orthostatic systolic blood pressure fall (69.0%, 78.3%), and overall definite cANP (44.8%, 92.8%). The statistical analysis revealed that the age-related 5th percentile is superior to the not-age-related cut-off values in diabetic patients. We therefore suggest that age-related normal values (percentiles) have to be applied when cANP is estimated.
Straub
R H
RH
Department of Internal Medicine I, University Hospital, Regensburg, Germany.
Lang
B
B
Palitzsch
K D
KD
Schölmerich
J
J
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001341:Autonomic Nervous System / Q000502:physiology*; D001795:Blood Pressure Determination; D002320:Cardiovascular Physiological Phenomena; D048909:Diabetes Complications; D003920:Diabetes Mellitus / Q000503:physiopathology; D003925:Diabetic Angiopathies / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D003929:Diabetic Neuropathies / Q000175:diagnosis* / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D011237:Predictive Value of Tests; D015995:Prevalence; D011680:Pupil / Q000502:physiology; D012129:Respiratory Function Tests; D012680:Sensitivity and Specificity