What is the impact of structural changes in society on diabetes self-management and trajectories of HbA1c? A cohort study before, during and after the COVID-19 pandemic in people with diabetes treated at outpatient clinics

M Martin Gillies Banke Rasmussen E Emilie Just-Østergaard J Jacob Volmer Stidsen I Ingrid Willaing G Grete Skøtt Pedersen

Abstract

Background The impact of COVID-19-related changes in diabetes self-management and trajectories of HbA1c throughout COVID-19 is not fully understood. Here, we describe HbA1c trajectories, changes in diabetes self-management and their association before, during and after the COVID-19 pandemic (2019–2022). Methods During the spring of 2021, we invited 13,641 outpatients from diabetes clinics in the Region of Southern Denmark to complete a questionnaire regarding changes in diabetes self-management during COVID-19. We linked the questionnaire and registry HbA1c data from before, during and after the COVID-19 pandemic and conducted multivariable adjusted linear mixed-effect regression to assess the association between changes in diabetes self-management and HbA1c. Results 5,581 (40.9%) people responded to the questionnaire (median age: 65 years, males: 59.7%). HbA1c decreased in people with type 2-diabetes and was unchanged for people with type 1-diabetes (interaction: p < 0.001). The majority of people reported unchanged diet (65–71%) and usual medication taking (89–90%). No changes in physical activity were reported by 43%, while 42% reported decreased physical activity. HbA1c trajectories did not differ according to change in physical activity and change in diet intake, while taking medication more regularly was associated with a decrease in HbA1c, from approximately 65/66 mmol/mol (8.1/8.2%) to 60/61 mmol/mol (7.6/7.7%) in both diabetes types. Conclusions During COVID-19, HbA1c trajectories differed between diabetes types. Most of the sample maintained usual diabetes self-management, although some decreased physical activity levels. Improved medication taking was associated with decreased HbA1c. This information is crucial for health professionals, in order to provide support aimed at reducing HbA1c.

Article Details

Journal PLoS ONE
Volume / Issue Vol. 20, Issue 8
Published August 12, 2025
Pages e0329394
ISSN 1932-6203
Publisher Public Library of Science

Journal Info

PLoS ONE

Public Library of Science

ISSN: 1932-6203 Open Access Health Sciences

Authors (5)

M

Martin Gillies Banke Rasmussen

E

Emilie Just-Østergaard

J

Jacob Volmer Stidsen

I

Ingrid Willaing

G

Grete Skøtt Pedersen