Guiding Inpatient Glycemic Management with Continuous Glucose Monitoring. A Prospective Nonrandomized Comparative Cohort Study

Continuous glucose monitoring (CGM) is a cornerstone of ambulatory diabetes management, and its utility in the inpatient setting remains underexplored. This study evaluated a CGM-guided management strategy against point-of-care capillary blood glucose (CBG) monitoring in adults who were hospitalized with hyperglycemia. We conducted a prospective, nonrandomized comparative cohort study, reported according to the Strengthening the Reporting of OBservational studies in Epidemiology (STROBE) statement, at a national referral center in Mexico City. A total of 338 adult inpatients with hyperglycemia were allocated to either the CGM group ( n = 169) or the standard CBG monitoring group( n = 169). The primary outcome was the percentage of glucose readings between 70 and 180 mg/dL, measured with intermittently scanned CGM in the CGM group and with a four-point daily capillary schedule at 06:00, 12:00, 18:00, and 24:00 in the CBG group. The capillary schedule yielded 6123 of 7024 scheduled measurements (87.2% capture), including 1431 at 24:00. Readings in range averaged 54.9% by CGM and 57.8% by CBG, based on approximately 96 and 4 daily measurements per patient, respectively. CBG at 24:00 was 27.0 mg/dL lower than the same patient daytime mean (95% CI, 20.9–33.0 lower; p < 0.001), with 79.2% of midnight readings in range versus 52.4% during the day. Hypoglycemia was distributed across the whole day, with 19.9% of CBG readings below 70 mg/dL recorded at 24:00, and seven patients had hypoglycemia detected only overnight. Time below 70 mg/dL was 10.5% by CGM and 5.6% by CBG; whereas, below 54 mg/dL was 3.7% and 1.4%, respectively. Mean glucose and the coefficient of variation improved from the first to the second half of hospitalization in both groups. The two groups recorded a similar percentage of readings in range, however, the sensor detected hypoglycemia twice as often. One in five capillary readings below 70 mg/dL was recorded at 24:00, and a daytime-only schedule would have missed all of them, as well as the hypoglycemia documented overnight in seven patients. ClinicalTrials.gov identifier NCT05096858. Enrollment began on 13 April 2020 and the record was first posted on 27 October 2021, hence, the study was in part retrospectively registered.