Glycemic variability elevates risk of vascular events, death

(HealthDay)—Visit-to-visit variability (VVV) in glycated hemoglobin (HbA1c) and fasting glucose correlate with major adverse outcomes for patients with type 2 diabetes, according to a study published online May 8 in Diabetes Care.

Yoichiro Hirakawa, M.D., from the University of Sydney in Australia, and colleagues examined the impact of VVV in HbA1c and fasting glucose on outcomes among patients with type 2 diabetes who were participating in the Action in Diabetes and Vascular Disease: Preterax and Diamicron MR Controlled Evaluation (ADVANCE) trial. The standard deviation of five measurements of HbA1c and glucose taken three to 24 months after randomization was used to define VVV among 4,399 patients in the intensive glucose treatment group.

The researchers found that an increase in VVV of HbA1c in the intensive group correlated with an increased risk of vascular events (P = 0.01) and with mortality (P < 0.001). After multivariable adjustment, the hazard ratios for the highest versus the lowest tenth were 1.64 and 3.31 for vascular events and mortality, respectively. VVV of fasting glucose correlated with increased risk of vascular events (hazard ratio, 2.70; P < 0.001). There was a positive association for HbA1c variability with the risk of macrovascular events (P = 0.02 for trend), while correlations were seen for glucose variability with macro- and microvascular events (P = 0.005 and 0.001 for trend, respectively). The results were broadly consistent in sensitivity analyses using other indices and for patients in the standard glucose treatment group.

"Consistency of glycemic control is important to reduce the risks of vascular events and death in type 2 diabetes," the authors write.

Several authors disclosed financial ties to pharmaceutical companies, including Servier International, which funded the ADVANCE trial.