Abstract
Long-term glycemic fluctuation has been associated with cardiovascular risk in
patients with type 2 diabetes mellitus (T2DM). However, the findings are
inconsistent. We performed a meta-analysis to summarize the association between
parameters of long-term glycemic variability and risk of cardiovascular events
in T2DM patients. Medline, Embase, and Web of Science databases were searched
for longitudinal follow-up studies comparing the incidence of cardiovascular
events in T2DM patients with higher or lower long-term glycemic variability. A
random-effect model incorporating the potential heterogeneity among the included
studies was used to pool the results. Twelve follow-up studies with 146 653 T2DM
patients were included. The mean follow-up duration was 4.9 years. Pooled
results showed that compared to those with the lowest glycemic variability,
patients with the highest glycemic variability had significantly increased risk
of cardiovascular events, as evidenced by the standard deviation of glycated
hemoglobin [HbA1c-SD: relative risk (RR)=1.44, 95% confidence
interval (CI): 1.23 to 1.69, p<0.001;
I2=70%], HbA1c coefficient of variation (HbA1c-CV:
RR=1.46, 95% CI: 1.19 to 1.79. p<0.001;
I2=83%), standard deviation of fasting plasma glucose
(FPG-SD: RR=1.33, 95% CI: 1.07 to 1.65, p=0.009;
I2=0%), and FPG coefficient of variation (FPG-CV:
RR=1.29, 95% CI: 1.01 to 1.64, p=0.04;
I2=47%). In conclusion, increased long-term glycemic
variability may be an independent risk factor for cardiovascular events in T2DM
patients.
Key words
glycemic variability - type 2 diabetes mellitus - cardiovascular events - meta-analysis