Fluctuations in HbA1c are associated with a higher incidence of cardiovascular disease in Japanese patients with type 2 diabetes
Article first published online: 1 AUG 2011
© 2011 Asian Association for the Study of Diabetes and Blackwell Publishing Asia Pty Ltd
Journal of Diabetes Investigation
Volume 3, Issue 2, pages 148–155, April 2012
How to Cite
Bouchi, R., Babazono, T., Mugishima, M., Yoshida, N., Nyumura, I., Toya, K., Hayashi, T., Hanai, K., Tanaka, N., Ishii, A. and Iwamoto, Y. (2012), Fluctuations in HbA1c are associated with a higher incidence of cardiovascular disease in Japanese patients with type 2 diabetes. Journal of Diabetes Investigation, 3: 148–155. doi: 10.1111/j.2040-1124.2011.00155.x
- Issue published online: 27 MAR 2012
- Article first published online: 1 AUG 2011
- Received 2 April 2011; revised 14 June 2011; accepted 19 June 2011
- Cardiovascular disease;
- HbA1c variability;
- Type 2 diabetes
Aims/Introduction: To reveal whether visit-to-visit variability in HbA1c is associated with higher risk of cardiovascular disease (CVD) in patients with type 2 diabetes.
Materials and Methods: The study was conducted on 689 Japanese patients with type 2 diabetes [295 women, 394 men; mean (±standard deviations (SD)) age 65 ± 11 years]. Variability in HbA1c was evaluated as the intrapersonal SD of serial measurements of HbA1c during the follow-up period for at least 12 months. Patients were divided into quartiles according to the SD of HbA1c, and the primary endpoint was defined as incident CVD. Cox’s proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI).
Results: During a median follow-up period of 3.3 years (range 1.0–6.3 years), 26 ± 14 measurements of HbA1c were obtained per patient and 61 episodes of incident CVD were recorded. The 5-year cumulative incidence of CVD in patients across the first, second, third, and fourth quartiles of SD in HbA1c was 4.9, 8.7, 17.1, and 26.2%, respectively (P < 0.001, log-rank test). Multivariate Cox regression analysis revealed that the incidence of CVD was significantly higher in patients in the fourth quartile of SD in HbA1c compared with those in the first quartile (HR 3.38; 95% CI 1.07–10.63; P = 0.039), independent of mean HbA1c and other traditional cardiovascular risk factors.
Conclusions: Variability of HbA1c may be a potent predictor of incident CVD in Japanese patients with type 2 diabetes. (J Diabetes Invest, doi: 10.1111/j.2040-1124.2011.00155.x, 2011)