Autonomic nervous system is well known to be affected by endocrine diseases and metabolic disorders ,hyperglycemia plays an integral role in this aspect which might alter both sympathetic and parasympathetic components.
The study was designed to assess the cardiac autonomic neuropathy in Iraqi diabetic subjects and to determine which division will be predominent (sympathetic or parasympathetic).
Department of Physiology in the Medical College of AL Mustansyriah University and the Section of Neurophysiology in Al Yarmouk Teaching Hospital.
PATIENTS AND METHODS:
Sixty subjects with Type 1 diabetes mellitus and sixty with Type 2 diabetes mellitus were enrolled in this study and their studied parameters were compared to sixty healthy individuals free from glucose intolerance assured by normal Oral Glucose Tolerance Test(OGTT) were regarded as a control group .Cardiovascular autonomic tests for all subjects ( healthy and diabetics) were done by using Ewing's battery reflex tests.
The results revealed the presence of significant difference between diabetic groups (type 1 & type 2) and control group regarding autonomic reflex tests including blood pressure response to standing and hand grip test (p>0.05) in type 1 DM and blood pressure response to standing (p>0.01) in type 2 DM. In this study 68.33% of diabetic subjects showed abnormal response to one or more of the performed tests. Also sympathetic involvement was found to be more common; (38.33%) for postural hypotension and (46.66%) for diastolic response to sustained hand grip testing while the parasympathetic division showed (32.75%) for valsalva maneuver and (31.66%) for beat to beat heart rate variation testing and (18.33%) for heart rate response to standing.
Diabetes mellitus affects cardiac autonomic system adversely with predominance to sympathetic division more than the parasympathetic component and this affection is aided by the duration of diabetes. So better glycemic control can delay the occurrence of cardiac complications associated with diabetes mellitus and in turn may improve life expectancy in diabetic subjects.