Efficacy of the Use of Real-time Continuous Glucose Monitoring on Glycemic Control in Patients With Type 2 Diabetes and Stage 3 and 4 Chronic Kidney Disease.

Patients diagnosed with type 2 diabetes mellitus and chronic kidney disease treated at the San Ignacio University Hospital in the outpatient clinic who meet the inclusion criteria will be identified. Once identified, they will be invited to participate in this study and will undergo the informed consent process, which will include, for those who accept, completing and signing the informed consent document (Appendix 1). It is clarified that the only intervention to be evaluated will be real-time continuous glucose monitoring; the patient's therapy will not be modified. The study will comprise a selection period and a treatment period.

4.3.1 Selection Period Potential subjects will sign an informed consent form before undergoing any procedure related to the study. During this phase, blinded continuous glucose monitoring will be performed to obtain baseline metabolic control data for 15 days prior to randomization. During this period, participants will be instructed to measure capillary blood glucose according to standard clinical practice. During this follow-up period, seven daily blood glucose readings will be taken to evaluate the device's accuracy in all patients.

4.3.2 Treatment Period Once the blinded monitoring data has been downloaded, randomization will begin. A simple, computer-generated randomization code will be used, managed centrally by a person who will not be aware of each patient's clinical characteristics. The assignment determined by this mechanism cannot be changed by the treating physicians.

• Intervention group (users of real-time continuous glucose monitoring). Participants in the intervention group will be instructed on the use of real-time continuous glucose monitoring. This training will be provided by nursing staff and will include instruction on device use, alarm management, and recommendations for responding to hypoglycemic episodes reported by the device. Alarms will be configured as follows: High Glucose Alert ≥240 mg/dL and Low Glucose Alert ≤70 mg/dL. Data uploaded to the platform by the device will be reviewed monthly by a physician trained in diabetes management, who will make appropriate adjustments to therapy if participants experience hypoglycemic episodes (<54 mg/dL and <70 mg/dL) or recurrent hyperglycemic episodes (>180 mg/dL), according to basal and prandial insulin titration recommendations. This group will be instructed to confirm readings below 70 mg/dL and above 240 mg/dL with capillary blood glucose monitoring to evaluate the device's accuracy within these ranges.
• Control group: Continuous glucose monitoring will be installed, blinded to measure baseline glycemic control metrics and at the end of the study. Patients assigned to the control group will receive routine nursing education on glucometer use, frequency of capillary blood glucose monitoring, and recommendations for managing hypoglycemic episodes. Capillary glucose data will be reviewed monthly by a physician trained in diabetes management, who will make appropriate adjustments to therapy if subjects experience hypoglycemic events (<54 mg/dL and <70 mg/dL) or recurrent hyperglycemic events (>180 mg/dL), according to basal and prandial insulin titration recommendations.

4.2.1 Inclusion Criteria

• Age over 18 years
• Chronic kidney disease defined as a glomerular filtration rate (GFR) of less than 60 ml/min/1.73 m², in at least two measurements within the six months prior to inclusion.
• Treatment with basal insulin, basal-bolus regimen, or co-formulation with or without oral antidiabetic agents, with or without a GLP-1 analogue, with stable treatment for the last 3 months.

4.2.2 Exclusion Criteria

• Type 1 diabetes.
• Severe cognitive impairment or dysfunction that prevents device management.
• Chronic kidney disease on renal replacement therapy (peritoneal dialysis or hemodialysis).
• Patients with a history of kidney transplantation.