Abstract
INTRODUCTION: Various studies have shown a number of glycemic parameters to improve over several weeks in people with type 1 diabetes during the first surge of the COVID-19 pandemic. Whether and to what extent such improvement is sustained during following COVID-19 surges remains unknown. Therefore, the aim of this study was to investigate glycemic parameters during the first year of the COVID-19 pandemic in people with type 1 diabetes and to determine factors associated with glycemic improvement. RESEARCH DESIGN AND METHODS: This was an observational cohort study in people with type 1 diabetes, aged ≥16 years. We compared glycated hemoglobin (HbA(1c)) and flash glucose monitoring (FGM) downloads between the prelockdown period and approximately 1 year thereafter. Using logistic regression analysis, we assessed associations between an HbA(1c) reduction of at least 0.5% (~5.5 mmol/mol) with baseline clinical characteristics and self-reported changes in psychological well-being and lifestyle behavior related to COVID-19. RESULTS: A total of 437 participants were included. As compared with prepandemic data, 1 year after the start of the COVID-19 pandemic and associated lockdowns, HbA(1c) had decreased from 7.9%±1.1% (63±12 mmol/mol) to 7.5%±1.0% (59±11 mmol/mol) (p<0.001), whereas time in range increased from 55.8%±16.7% to 58.6%±16.7% (p=0.004) and time below (<3.9 mmol/L) and above (>13.9 mmol/L) range and glucose variability all decreased (all p<0.05). FGM use, higher HbA(1c) at baseline and current smoking were independently associated with an HbA(1c) decrease of at least 0.5%, whereas self-reported changes in psychological well-being and lifestyle behavior related to the first surge of the COVID-19 pandemic and associated lockdowns were not. CONCLUSIONS: The COVID-19 pandemic and related lockdown measures were associated with improvement in glucometrics, including HbA(1c) and FGM data, in individuals with type 1 diabetes, particularly in FGM users, those with higher HbA(1c) at baseline or current smokers.