Diabetes Knowledge and Metabolic Control in Type 1 Diabetes Starting With Continuous Glucose Monitoring

PURPOSE: To investigate whether diabetes knowledge and health literacy impact glycemic control after 1 year of intermittently scanned continuous glucose monitoring (isCGM) in people with type 1 diabetes  ≥ 16 years.

METHODS: In this prospective real-world cohort study, we assessed diabetes knowledge using a new 10-item questionnaire [Patient Education and Knowledge (PEAK)] and health literacy using the validated 6-item Newest-Vital Sign-D (NVS-D) questionnaire. Primary endpoint was association between PEAK score and change in hemoglobin A1c (HbA1c). Secondary endpoints were link between NVS-D score and change in HbA1c and that between time spent in/above/below range and PEAK/NVS-D scores.

RESULTS: 851 subjects were consecutively recruited between July 2016 and July 2018. Median PEAK score was 8 (range: 0-10), and median NVS-D score was 6 (range 0-6). HbA1c evolved from 7.9% (7.8%-8.0%), 63 (62-64) mmol/mol, at start to 7.7% (7.6%-7.7%), 61 (60-61) mmol/mol (P < 0.001), at 6 months and to 7.8% (7.7%-7.9%), 62 (61-63) mmol/mol, at 12 months (P < 0.001). HbA1c only improved in subgroups with higher scores [PEAK subgroups with score 7-8 (P = 0.005) and 9-10 (P < 0.001) and NVS-D score 4-6 (P < 0.001)]. At 12 months, time spent below 70 mg/dL was reduced by 15% (P < 0.001), and time spent below 54 mg/dL was reduced by 14% (P < 0.001), irrespective of PEAK/NVS-D score. Multiple linear regression analysis demonstrated an association of PEAK score, scan frequency, and baseline HbA1c with evolutions in time in range and time in hyperglycemia.

CONCLUSIONS: isCGM reduced time in hypoglycemia, and HbA1c evolved favorably. Our findings suggest that diabetes and health literacy affect glucometrics, emphasizing the importance of education.