To describe glycemic control in diabetic patients monitored by glycated hemoglobin (HbA1c) before, during and after COVID-19 confinement. To identify factors, measured before confinement, associated with HbA1c testing during confinement and those associated with a 1 % increase in HbA1c after confinement.

Retrospective, descriptive study of diabetic patients over 18 years old who underwent at least one HbA1c test before and after confinement. The data were collected from medical analysis laboratories in the Auvergne region (France) and included HbA1c measurements between March 17, 2019, and May 11, 2021, age, sex, residential area, and medical specialty of the prescribing physician.

70,286 patients were included (54.1 % men, mean age 71.7 ± 13.1 years). The average preconfinement HbA1c level (6.80 % ± 1.16) was similar to the average post-confinement HbA1c level (6.80 % ± 1.14). A larger median reduction of 0.90 % points in HbA1c level in the year following confinement was observed in patients whose preconfinement HbA1c level was ≥ 9 %. Only 24.5 % of the patients had an HbA1c test performed during confinement, the majority of whom were over 80 years of age and had an average HbA1c level between 7 and 9 % before confinement. For 5.1 % of the patients, the average HbA1c level increased by one percentage point or more after confinement. Patients ≤ 64, those with an insufficient number of blood tests before confinement and those with an imbalance in HbA1c before confinement were at risk of glycemic imbalance after confinement.

Confinement had no impact on HbA1c levels in diabetic patients.