The use of continuous glucose monitoring has been suggested as a method of determining glucose control in prediabetes, including understanding glucose variability, which may be a risk factor in the progression to type 2 diabetes. This pilot research study aimed to determine glycemic variability (%CV) in people diagnosed with impaired glucose tolerance (IGT)/prediabetes. The study included people aged 18 or over, with their most recent HbA1c 5.7-6.4% (39-47 mmol/mol) recorded in medical notes in the last 12 months. Pregnant patients were excluded, as were patients with diabetes. A total of 43 participants (60.5% female) from 5 primary care sites in the UK enrolled in the 2-week single arm study, wearing a FreeStyle Libre Pro Flash Glucose Monitoring SystemTM (glucose data was not available to participants). On average, HbA1c was 6.06±0.25% (42.7±2.6 mmol/mol), age was 62.5±8.3 years, BMI was 32.1±6.6 kg/m2, average time since diagnosis was 18±19 months, average Q diabetes score was 28.4±23.7% (mean±SD). Glucose variability (%CV) was 17.3±3.8%, %CV was greater during daytime hours (06:00 to 23:00) than at night (23:00 to 06:00), 17.7±4.1% and 12.9±3.5% respectively (mean±SD). %CV was greater in those with BMI<30 kg/m2 compared to those ≥30 kg/m2; 18.9±3.3% and 15.8±3.5% respectively (mean±SD). Mean glucose was 101.2±10.0 mg/dL, time in hyperglycemia (>180 mg/dL, 10.0 mmol/L) was 0.09±0.23 hours per day (mean±SD). Ten anticipated sensor insertion site symptoms were experienced by five participants: erythema (n=2, well-defined redness), pain (n=1), bruising (n=1), itching (n=2), rash (n=2), bleeding (n=1) and other (n=1, ‘skin irritation’), all were mild in severity and resolved. This population, with prediabetes experienced glucose variability of 17.3% (%CV). This was greater during daytime hours and in those with lower BMI (<30 kg/m2).


K. Douglas: None. N. Annamalai: None. P.J. Moore: None. S. Thomson: Research Support; Self; Abbott. Research Support; Spouse/Partner; Abbott.

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at