Does visit-to-visit glycemic fluctuation influence long-term outcomes in type 2 diabetes (T2DM)? A retrospective cohort study published in Diabetes, Obesity and Metabolism assessed whether hemoglobin A1c (HbA1c) variability was associated with mortality and diabetes-related complications among adults receiving specialist outpatient care.

The study included 18,293 adults with type 2 diabetes managed between 2009 and 2017. HbA1c variability was assessed using three metrics: intra-individual visit-to-visit coefficient of variation (COV), variation independent of mean (VIM), and the HbA1c Variability Score (HVS). Outcomes included mortality, acute myocardial infarction (AMI), stroke, lower extremity amputation (LEA), neuropathy, and nephropathy, identified through diagnosis and service codes. Cox proportional hazards and weighted Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

Compared with patients in the lowest quartile of HbA1c variability, those in the highest quartile had higher risks of mortality (COV HR 2.03, 95% CI 1.43-2.88; VIM HR 2.70, 95% CI 1.61-4.53; HVS HR 2.32, 95% CI 1.49-3.62) and nephropathy (COV HR 1.34, 95% CI 1.14-1.56; VIM HR 1.31, 95% CI 1.14-1.52; HVS HR 1.20, 95% CI 1.04-1.39). No statistically significant associations were observed for AMI, stroke, neuropathy, or LEA.

These findings indicate that higher visit-to-visit HbA1c variability was associated with increased risks of mortality and nephropathy in this outpatient cohort.