Long-term impact of continuous glucose monitoring on glycemic and metabolic control in type 1 diabetes: A three-year real-world evaluation.

BACKGROUND: This study evaluates the long-term effectiveness, safety, and metabolic impact of sustained continuous glucose monitoring (CGM) use over 36 months in individuals with type 1 diabetes mellitus (T1D) managed in routine clinical practice.

METHODS: This retrospective real-world cohort study included 314 individuals with T1D who initiated CGM and maintained continuous use for three years. Clinical, laboratory, and CGM-derived data were collected at baseline and at approximately 12-, 24-, and 36-month intervals.

RESULTS: Median HbA1c decreased from 8.5% at baseline to 7.8% at 12 months and remained stable at 7.7% at T24 and T36 (p < 0.001). The median time in range increased from 57% at T12 to 68% at T24 and then decreased to 63% at T36. Severe hypoglycemia exposure (%TBR<54) remained minimal. Median glycemia risk index improved from 53.4 at T12 to 38.2 at T24 and increased to 47.0 at T36. Median insulin dose declined from 1.3 IU/kg/day at baseline to 1.0 at T12-T24 and 1.1 at T36, while median body weight decreased from 69 to 67 kg at T12 and remained stable. Diabetes-related hospitalizations declined progressively over the follow-up period, with statistically significant reductions observed at T24 and T36 compared with baseline (6.1% to 1.9% at T36; p = 0.009). Median hypoglycemia events declined from 5 to 4 per 28 days.

CONCLUSIONS: Sustained CGM use in real-world clinical practice was associated with durable changes in glycemic control, safety, and healthcare utilization over three years. These findings suggest the long-term clinical value of CGM when embedded within structured diabetes care programs.