Heart Rate Variability in Diabetes: Relationship to Age and Duration of the Disease

Abstract

Heart rate variability (HRV) during deep breathing was studied with a neonatal heart monitor in 143 control subjects and 218 patients with diabetes (102 with IDDM and 116 with NIDDM). In the control group HRV decreased after age 20 by 4-5 beats per decade (from 29.7 +/- 5.8 beats at age 20-29 to 11.8 +/- 5.4 beats at age 60+). In all age groups HRV in IDDM was lower than in the controls, and both age and duration of diabetes played a role in the decrease of HRV (from 21.5 +/- 5.3 beats at age 20-29 to 6.3 +/- 5.4 at age 60+). In NIDDM aging seemed to play a less important role, and the influence of the duration of the disease was not statistically significant. In both groups of patients the frequency of HRV below the 2.5th percentile was 82% in those with symptoms and/or signs of autonomic neuropathy, 64% in patients with peripheral neuropathy only, and 36% in those who had no obvious signs or symptoms of neuropathy. Interindividual variability was pronounced, and age and duration of the disease together accounted for only 36% of the observed differences between IDDM and the controls. Determination of HRV with a standard neonatal heart monitor presents an easy, simple, and nonstressful test of cardiac autonomic neuropathy. The norms of the test are age related.

Glutamic acid decarboxylase antibodies, autonomic nerve antibodies and autonomic neuropathy in diabetic patients

“…The putative correlation between neuropathy and GAD-ab [11] might, however, have reflected the duration of diabetes and not neuropathy as was recently 297 suggested in a preliminary report [32]. Signs of peripheral [33] and autonomic [34,35] dysfunction are known to increase with the duration of diabetes. In the present study, however, GAD-ab were detected in patients with a long duration of IDDM without signs of neuropathy.…”

“…A "new" development of GAD-ab, could also be the rational behind the presence of GAD-ab in our cross-sectionally tested material. In the cross-sectional material, some patients were tested for C-peptide and found to be negative [34]. Hence, it is unlikely that preserved beta-cell function explained the occurrence of GADab in these patients; lack of preserved beta-cell function has also been noticed in other long-term IDDM patients with GAD-ab [9,10].…”

Disparity of autonomic control in type 2 diabetes mellitus

“…By design, our findings were obtained in patients with type 2 diabetes who had no evidence of neuropathy, because this could interfere with autonomic neural control and its effects [33][34][35][36]. We used previously accepted criteria [19,20], as well as clinical examination and vasopressor responses, to exclude somatic and autonomic neuropathy.…”

“…Our study design also avoided confounding effects when comparing patients with type 2 diabetes with control subjects. We avoided the potential effects of race, age, body weight, time of day, dietary sodium intake, arterial blood pressure level, visceral distension, alcohol, nicotine and exercise on the autonomic drive [36,[38][39][40][41][42][43][44][45][46]. These criteria were satisfied by closely matching the three groups and by using the same protocol for all subjects.…”

Heartbeat and arrhythmia perception in diabetic autonomic neuropathy

“…At the same time, the cardiovascular innervation disorder appears to be an early symptom of diabetic autonomic neuropathy (Lehmann et al 1985). Cardiac signs of autonomic neuropathy are reductions in spontaneaus variability, in nocturnal decrease and in stress adaptation of the heart rate (Ewing et al 1984 ;Masaoka et al 1985), as weil as an increased basal heart rate (Ciarke & Ewing, 1982) and an increased number of arrhythmias (Runge & Kühnau, 1983). The impaired cardiac perception in diabetic autonomic neuropathy is one of the possible causes of asymptomatic angina pectoris and silent myocardial infarction (Faerman et al 1977 ;Clarke et al 1979;Runge & Kühnau, 1983;Stalmann et al 1987).…”