Impact of COVID-19 lockdowns on glycemic control across age groups based on a retrospective isCGM analysis from Poland 2020–2021

Most European countries experienced three COVID-19 waves in 2020-2021. In Poland, Wave 1 (March-July 2020) was associated with a severe lockdown prohibiting external social activities beyond every-day necessities. During Waves 2 and 3 some restrictions were reimplemented, however, impacted everyday life less. The study aimed to analyze the individual as well as long-term impacts of COVID-19 pandemic lockdowns on glycemic control in different age groups of people with diabetes using intermittently scanned continuous glucose monitoring (isCGM), in Poland. We analyzed retrospective data from isCGM users during the COVID-19 pandemic (from January 2020 to September 2021), describing glucometrics according to the International Consensus on time in range (TIR). Longitudinal data were analyzed from 680 Polish patients with diabetes, comprising 470 adults aged 18-64, 66 adults aged 65+, and 144 children and adolescents. The most evident improvement in glycemic indices was observed during the first, most severe lockdown, especially in adults (TIR 68.2 vs. 65.6%). For seniors, most indices were stable during the pandemic, with only small improvement in time below range (TBR) (TBR70 1.9 vs. 2.6%). The comparison of the pre-pandemic and post-lockdown periods showed that most glycemic indices returned to similar levels, however, in children and adolescents, some deterioration was seen. Changes in glycemic indices during the COVID-19 pandemic in 2020-2021 in patients using isCGM differed between the 3 lockdown events and between age groups. Results demonstrate an age dependency in users' response to the COVID-19 lockdowns in Poland and suggest that behavior changes brought on by dramatic lifestyle changes associated with COVID lockdowns were not sustained following the pandemic.