Impact of short-term glycemic variability on risk of all-cause mortality in type 2 diabetes patients with well-controlled glucose profile by continuous glucose monitoring: A prospective cohort study

Aims To investigate the association between short-term glycemic variability (GV) and all-cause mortality in type 2 diabetes with well-controlled glucose profile by continuous glucose monitoring (CGM). Methods In this prospective study, 1839 diabetes patients who reached percentage of time in the target glucose range of 3.9–10 mmol/L > 70%, percentage of time above range of 10 mmol/L < 25% and percentage of time below range of 3.9 mmol/L < 4% on CGM were enrolled and were classified into five groups by coefficient of variation for glucose (%CV) level: ≤20%, 20–25%, 25–30%, 30–35%, and > 35%. Cox proportional hazard models were used to estimate hazard ratios (HRs) of all-cause mortality risk associated with the different %CV categories. Results At baseline, participants had mean age of 60.9 years and mean HbA1c of 7.3% (56 mmol/mol). A total of 165 deaths were identified during a median follow-up of 6.9 years. In multivariate Cox regression analysis, HRs associated with %CV categories were 1.00, 1.16 (95% CI 0.78–1.73), 1.38 (95% CI 0.89–2.15), 1.33 (95% CI 0.77–2.29) and 2.26 (95% CI 1.13–4.52) for all-cause mortality. Conclusions Greater %CV was associated with increased risk for all-cause mortality even among patients with seemingly well-controlled glucose status.