Heart rate variability in adolescents and adults with type 1 diabetes.
BACKGROUND
Limited data are available regarding the onset or trajectory of cardiovascular autonomic deterioration in persons with type 1 diabetes.


OBJECTIVE
To describe differences in heart rate variability among adolescents with type 1 diabetes, adults with type 1 diabetes who have coexisting renal failure, and adolescent and adult controls.


METHODS
A correlational design was used to compare the status of heart rate variability in adults with type 1 diabetes and renal failure (n = 62); healthy adult controls (n = 67); adolescents with type 1 diabetes (n = 55); and healthy adolescent controls (n = 28). Convenience samples of adult patients with diabetes awaiting kidney or pancreas and kidney transplantation, and adolescents with diabetes were recruited from local university-based clinics. Volunteers served as healthy controls. The short-term R-R variability measures included in this study were changes in heart rate with deep breathing and with the Valsalva maneuver. Twenty-four hour ambulatory heart rate monitoring with power spectral analysis was also obtained to assess longterm R-R variability.


RESULTS
Adult patients with type 1 diabetes awaiting transplantation had significantly poorer heart rate variability measures than any of the other three populations studied (p < .0001). Adult control values also were significantly lower than either teenage controls or youths with diabetes (p < .05). Although most long-term R-R variability measures were lower in adolescents with diabetes versus controls, only one measure of parasympathetic modulation (i.e., pNN50) was significantly lower (p = .042). There were significant negative associations between HbA1c and sympathetic modulation (i.e., low hertz) in both the adult group (r= -.406, p = .029) and the adolescent group (r= -.324, p = .025) with diabetes.


CONCLUSIONS
Type 1 diabetes is associated with decreased heart rate variability, with the extent of the decrease related to the age of the individual and the severity of the disease.
Faulkner
M S
MS
College of Nursing, Department of Maternal and Child Nursing, University of Illinois at Chicago, 60612-7350, USA. melissaf@uic.edu
Hathaway
D K
DK
Milstead
E J
EJ
Burghen
G A
GA
D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000704:Analysis of Variance; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D017776:Autonomic Pathways / Q000503:physiopathology; D016022:Case-Control Studies; D003922:Diabetes Mellitus, Type 1 / Q000150:complications*; D003929:Diabetic Neuropathies / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005260:Female; D006331:Heart Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D006339:Heart Rate; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008297:Male; D017678:Sex Distribution; D013997:Time Factors; D014636:Valsalva Maneuver