title: Natural progression of cardiac autonomic neuropathy in patients with type 1 diabetes: a four-year follow-up study.
abstract: OBJECTIVE
  To determine the prevalence and clinical characteristics of cardiac autonomic neuropathy in type 1 diabetic patients who were followed up for 4 years to shed further light on the natural progression of cardiac autonomic neuropathy.
  
  
  METHODS
  It is a prospective cohort observational study, consisted of 57 patients who were originally studied using the standard tests proposed by Ewing and Clarke (1985). At two years follow up, 46 patients were reevaluated, 55 patients from the original study were reevaluated after another 2 years for the 3rd time using the same protocol. The control group comprised 30 age and sex matched healthy volunteers. McNemar test, ANOVA for repeated measurements, paired t test and unpaired t test were used for statistical analyses.
  
  
  RESULTS
  The prevalence of established cardiac autonomic neuropathy (CAN) at the beginning was 14%. Q-Tc intervals were found to be significantly higher in patients with abnormal cardiovascular reflex (CVRs) in the 2nd examination (0.4±0.04 vs 0.5±0.05 sec, p=0.006). Eighteen patients showed deterioration of their CVRs test between 1st and 3rd examination. There was deterioration of their glycemic control guided by glycosylated hemoglobin (8.5±1.4 vs 9.9±1.5%, p=0.05*) and albumin/creatinine ratio (4.4±4.0 vs 28.2±28.0 mg/g creatinine, p=0.04). On the other hand, 12 patients showed regression of their CVRs test. Only their insulin dose showed significant decrease (1.8±1.3 vs 1.1±0.3 dose/kg, p=0.02).
  
  
  CONCLUSIONS
  The prevalence of established CAN in diabetic patients is high at the beginning of the study. Glycosylated hemoglobin, systolic and diastolic blood pressure were significantly increased in diabetics with deterioration of their CAN. However, the dose of insulin was significantly decreased in diabetics with regression of their CAN.
authors.affiliation: Department of Pediatrics, National Research Centre, Cairo, Egypt. S_eldayem@yahoo.com
authors.forename: Soha M
authors.initials: SM
authors.lastname: Abd El Dayem
authors.forename: Ahmed A
authors.initials: AA
authors.lastname: Battah
authors.forename: Randa A
authors.initials: RA
authors.lastname: Soliman
mesh_terms: D000293:Adolescent; D000419:Albuminuria / Q000175:diagnosis; D001341:Autonomic Nervous System / Q000503:physiopathology; D001342:Autonomic Nervous System Diseases / Q000209:etiology*; D001794:Blood Pressure / Q000502:physiology; D002319:Cardiovascular System / Q000294:innervation / Q000503:physiopathology; D016022:Case-Control Studies; D002648:Child; D015331:Cohort Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications* / Q000188:drug therapy; D003929:Diabetic Neuropathies / Q000209:etiology*; D018450:Disease Progression; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006442:Glycated Hemoglobin / Q000032:analysis; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage; D007328:Insulin / Q000008:administration & dosage; D008297:Male; D011446:Prospective Studies; D055815:Young Adult
chemical_list: D006442:Glycated Hemoglobin; D007004:Hypoglycemic Agents; D007328:Insulin