ABSTRACT
For assessing the alterations of circadian heart rate variability 66 diabetic patients (age: 52.9 +/- 1.0 years; x +/- SEM) and 23 control subjects (age: 52.7 +/- 1.7 years) were investigated using 24 hours Holter monitoring. Autonomic neuropathy (AN) was evaluated by tests for cardiovascular reflexes and patients were classified as being without AN (n = 26), having mild (n = 25) or definitive (n = 15) signs of AN. Minimal heart rates were significantly higher while maximal heart rates were considerably lower in patients with than without AN (60 +/- 2 min-1 versus 54 +/- 1, min-1, p < 0.05 and 125 +/- 4 min-1 versus 146 +/- 4 min-1, p < 0.01). Diabetic groups were comparable regarding values of averaged heart rates. The difference between the mean waking and sleeping averaged heart rates was the smallest in diabetic patients with definitive signs of AN (9 +/- 2 min-1) differing from those of control subjects (17 +/- 1 min-1, p < 0.01) and diabetic patients without (17 +/- 1 min-1, p < 0.001) or with mild (15 +/- 1 min-1, p < 0.05) signs of AN. Characteristic alteration, i.e. a reduction in circadian heart rate variability could be found in diabetic patients with signs of AN. This phenomenon has primarily been a consequence of more frequent sleeping heart rates due to dominant impairment in cardiac parasympathetic innervation.
Subject(s)
Autonomic Nervous System Diseases/physiopathology , Diabetic Neuropathies/physiopathology , Heart Rate , Analysis of Variance , Autonomic Nervous System Diseases/etiology , Circadian Rhythm , Electrocardiography, Ambulatory , Female , Humans , Male , Middle AgedABSTRACT
In order to assess the relationship between abnormal but silent ST-segment depression and autonomic neuropathy 63 diabetic patients (age: 40-71 years, duration of diabetes: 2-32 years) without a history of angina pectoris were investigated. Transient ST-segment depression was assessed by 24 hours Holter monitoring and, in addition, dynamic exercise on bicycle ergometer was also performed in all but 7 patients. Autonomic neuropathy was evaluated by cardiovascular function tests (deep breathing, Valsalva manoeuvre and lying-to-standing). Abnormal ( > or = 2 mm) ST segment depression was observed in 11 patients (18%) while signs of autonomic neuropathy were found in 37 diabetics (59%). Signs of autonomic neuropathy were significantly (p < 0.01) more often documented in patients with (11/11) than without (26/52) abnormal ST-segment depression. It was concluded that autonomic neuropathy could be a possible explanation for lacking symptoms from abnormal ST-segment depression in diabetic patients.
Subject(s)
Autonomic Nervous System Diseases/diagnosis , Diabetic Neuropathies/physiopathology , Electrocardiography , Adult , Aged , Autonomic Nervous System Diseases/physiopathology , Diabetic Neuropathies/diagnosis , Exercise Test , Female , Humans , Male , Middle Aged , Myocardial Infarction/diagnosis , Myocardial Infarction/physiopathologyABSTRACT
In order to clarify the origin of hyperglycaemia, blood glucose, glycated haemoglobin (GHb) and protein-corrected serum fructosamine (SFA) values were simultaneously determined at admission of 65 patients with acute myocardial infarction while oral glucose tolerance test was performed later at discharge. In 29 patients no alterations in carbohydrate metabolism were found (blood glucose: 5.2 +/- 0.1 mmol/l, GHb: 4.4 +/- 0.1%, SFA: 2.20 +/- 0.08 mmol/l) while in 9 patients diabetes was already recorded in the medical history (blood glucose: 11.5 +/- 1.1 mmol/l, GHb: 7.9 +/- 0.9%, SFA: 3.36 +/- 0.31 mmol/l, p < 0.001). Undiagnosed diabetes was documented in 8 patients (blood glucose: 11.8 +/- 1.3 mmol/l, GHb: 7.3 +/- 0.6%, SFA: 3.51 +/- 0.24 mmol/l) while stress-hyperglycaemia was found in 19 patients (blood glucose: 8.4 +/- 0.3 mmol/l, GHb: 4.5 +/- 0.1%, SFA: 2.55 +/- 0.17 mmol/l). Undiagnosed diabetes could be recorded in one seventh while stress-hyperglycaemia could be found in one third of non-diabetic patients with acute myocardial infarction. Due to overlapping values SFA is not suitable to distinguish between stress-hyperglycaemia and undiagnosed diabetes in patients with acute myocardial infarction.
