Predictors of abnormal cardiovascular autonomic function measured by frequence domain analysis of heart rate variability and conventional tests in patients with type 1 diabetes.

Abstract

. S.M. and A.S. contributed equally to this article. Abbreviations: DCCT, Diabetes Control and Complications Trial; E/I ratio, ratio of length of R-R intervals during expiration to inspiration; ETDRS, Early Treatment of Diabetic Retinopathy Study; HF, high frequency; HFnorm, normalized high frequency component; HRV, heart rate variability; LF, low frequency; LFnorm, normalized low frequency component; RMSSD, square root of the mean square of R-R interval differences; TP, total power; UAER, urinary albumin excretion rate; VLF, very low frequency.A OBJECTIVE -Frequency domain analysis of heart rate variability (HRV) is used to assess cardiovascular autonomic function. There are no prospective data on the sensitivity of its various components to glycemia or other diabetes-related risk factors compared with conventional tests and with other complications of diabetes. RESEARCH DESIGN AND METHODS -In 1985, possible risk factors of future complications were determined in 115 children with type 1 diabetes. In 1996, the presence of complications (HRV analysis, conventional tests of autonomic function, urinary albumin excretion rate [UAER], and retinopathy) were assessed in 83 of these patients (age 32 ± 1 years, duration of diabetes 22 ± 1 years). RESULTS -Poor glycemic control (measured as lifetime glycemic exposure or HbA 1c in 1985)was the most important independent predictor of decreases in all measures of absolute power of HRV (total power [TP] and very low frequency, low frequency [LF], and high frequency [HF] power) and square root of the mean square of R-R interval differences but not of changes of normalized measures or ratios (normalized HF and LF, LF/HF). Other significant independent predictors of autonomic dysfunction were late age of onset of diabetes, female sex, and high BMI. To examine the sensitivity of the various tests to glycemia, the patients were divided into tertiles based on lifetime glycemic exposure (A 1c months). Glycemic exposure in the tertiles averaged 194 ± 25 A 1c months (20 years of HbA 1c 0.8% above normal), 556 ± 19 A 1c months(20 years of HbA 1c 2.3% above normal), and 963 ± 30 A 1c months (20 years of HbA 1c 4% above normal). Tests of complications that were significantly abnormal in patients already in the lowest tertile and were correlated with glycemia were TP and severity of retinopathy. Of conventional tests, only the ratio of length of R-R intervals during expiration to inspiration (E/I ratio) was significantly related to glycemic exposure, but it required high glycemic exposure (20 years of HbA 1c 4% above normal) to be abnormal. UAER was significantly increased only in the highest tertile of glycemic exposure.CONCLUSIONS -TP and retinopathy score were much more sensitive to antecedent glycemia than conventional tests of autonomic function or UAER and were significantly abnor-

Deep breathing improves blunted baroreflex sensitivity even after 30 years of type 1 diabetes

“…The patients with a long duration of diabetes had initially participated in another study and were recruited to the present study at a follow-up visit. The original study comprised 110 patients at baseline in 1985, out of whom 83 were re-studied in 1996 [20]. These participants were diagnosed with type 1 diabetes between 1968 and 1978 and had an age at onset of less than 15 years.…”

Cardiovascular Endurance and Heart Rate Variability in Adolescents With Type 1 or Type 2 Diabetes

“…In addition, DM predisposes individuals to cardiovascular dysautonomia (Faulkner, Hathaway, Milstead, & Burghen, 2001;Hathaway, Cashion, Wicks, Milstead, & Gaber, 1998;Makimattila et al, 2000). Cardiovascular autonomic neuropathy with impaired HRV leads to debilitating complications and is an independent marker of poor prognosis for persons with DM (Burger, Charlamb, Weinrauch, & D'Elia, 1997;Levitt, Stansberry, Wynchank, & Vinik, 1996;Liao, Carnethon, Evans, Cascio, & Heiss, 2002;Osterhues, Grossmann, Kochs, & Hombach, 1998; Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology, 1996).…”

Assessment of Cardiac Autonomic Regulation in Children with Monosymptomatic Nocturnal Enuresis by Analysis of Heart Rate Variability

“…The present study has shown that parasympathetic nervous system functions are hyperactive in children with MNE. There are many studies, which evaluated the cardiac autonomic regulation by the power spectral analysis and time dependent analysis using 24-hour Holter electrocardiogram (Goto et al 1997;Massin et al 1997;Makimattila et al 2000;Martini et al 2001;Yang et al 2001;Kazuma et al 2002;Mehta et al 2002;Park et al 2002). The power spectrum of heart rate variabil- SDNN, the standard deviation of all normal sinus R-R intervals over 24 hours; SDANN, standard deviation of all averaged normal sinus intervals for each 5-minute segment in the 24-hour recording; rMSSD, the root mean square of successive differences between normal sinus R-R intervals.…”