The effect of intensive diabetes treatment on resting heart rate in type 1 diabetes: the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Study
- Andrew D. Paterson, M.D. (andrew.paterson{at}utoronto.ca)1,
- Brandy N. Rutledge, Ph.D.2,
- Patricia A. Cleary, M.S.2,
- John M. Lachin, Sc.D.2,
- Richard S. Crow, M.D.3 and
- the Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications Research Group
- 1 Program in Genetics and Genomic Biology, The Hospital for Sick Children, 101 College Street, Toronto, and Departments of Public Health Sciences, Psychiatry and Institute of Medical Sciences, University of Toronto, Toronto, Ontario, Canada
- 2 Biostatistics Center, 6110 Executive Blvd Suite 750, The George Washington University, Rockville, MD 20852, USA
- 3 Minnesota ECG Coding Center, Division of Epidemiology, School of Public Health, University of Minnesota, 1300 South Second Street, Suite 300, Minneapolis, MN 55454, USA
Abstract
Objective: Cardiovascular disease is a major cause of morbidity and mortality in individuals with type 1 diabetes. Resting heart rate (RHR) is a risk factor for cardiovascular disease in the general population and case-control studies have reported a higher RHR in individuals with type 1 diabetes. In individuals with type 1 diabetes there is a positive correlation between HbA1c and RHR; however, no prospective studies have examined whether a causal relationship exists between HbA1c and RHR. We hypothesized that there is an effect of intensive diabetes treatment, aimed at achieving normal HbA1c levels, on RHR in individuals with type 1 diabetes.
Research Design and Methods: 1,441 individuals with type 1 diabetes who participated in the Diabetes Control and Complications Trial (DCCT) had their RHR measured biennially by ECG during the DCCT, and annually for ten years during the Epidemiology of Diabetes Interventions and Complications (EDIC) follow-up study.
Results: During the DCCT, intensive treatment was associated with lower mean RHR than conventional treatment, both in adolescents (69.0 vs. 72.0 beats per minute; 95% CI 62.8-75.7 and 65.7-78.9, respectively, p=0.013) and adults (66.8 vs. 68.2; 95% CI 65.3-68.4 and 66.6-69.8, respectively, p=0.0014). During follow-up in EDIC, the difference in RHR between the treatment groups persisted for at least 10 years (p<0.0001).
Conclusions: Compared with conventional therapy, intensive diabetes management is associated with lower RHR in type 1 diabetes. The lower RHR with intensive therapy may explain, in part, its effect in reducing cardiovascular disease, recently demonstrated in type 1 diabetes.
Footnotes
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- Received August 11, 2006.
- Accepted April 23, 2007.
- Copyright © American Diabetes Association
