Abstract 10881: Impact of Successive Glycated Hemoglobin Level on Cardiovascular Events in Patients With Type 2 Diabetes
Objectives: Appropriate glycemic control for preventing cardiovascular events in patients with diabetes is still under investigation. We investigated whether appropriate threshold of glycated hemoglobin (HbA1c) existed in type 2 diabetic patients.
Methods: JPAD2 study is a prospective cohort study of patients who enrolled in JPAD trial, a randomized controlled trial to examine the efficacy of low-dose aspirin for primary prevention of cardiovascular events in type 2 diabetic patients started in 2002. After the completion of trial in 2008, we followed the cohort until 2011. Primary end points were composite of fatal/nonfatal ischemic heart disease, fatal/nonfatal stroke, peripheral arterial disease, and sudden death. HbA1c (NGSP) was measured every year, and the mean HbA1c during the follow-up was calculated.
HRs of clinically dichotomized mean HbA1c were calculated by Cox proportional hazard model adjusting for age, smoking status, blood pressure, duration of diabetes, and use of insulin, calcium antagonist, and statins. We also estimated the adjusted HR of 1% increment of mean HbA1c.
Results: From the JPAD started, 2536 patients with a median follow-up of 7.1 years [95% CI 7.0-7.2] were analyzed. The median HbA1c at baseline was 7.2% [IQR 6.6-8.1] and median of individual mean HbA1c during the study period was 7.2% [IQR 6.6-7.9]. Adjusted HRs of HbA1c>=7.4% was 1.5 [95%CI 1.2-2.0] and the HRs were consistent when the threshold became lager (Figure). When threshold changed to 7.2% or less, the HR closed to 1. However, when thresholds were lower than 7.0%, the HRs lost their stability, partially due to small samples size. Adjusted HR of 1% increment of HbA1c was 1.2 [95%CI 1.05-1.34].
Conclusion: Keeping HbA1c under 7.4% should be encouraged to reduce the risk of cardiovascular events in type 2 diabetic patients. The long-term effect and the lower threshold also should be scrutinized when JPAD2 study is completed with enough long follow-up period.
- © 2013 by American Heart Association, Inc.