Impact of the COVID‐19 pandemic on the glycemic control, eating habits, and body compositions of people with diabetes mellitus: A retrospective longitudinal observational study

AIMS/INTRODUCTION: To evaluate the impact of the COVID‐19 pandemic on the glycemic control, eating habits, and body composition of people with diabetes mellitus; to identify the determinants of worsening glycemic control in people with diabetes mellitus. MATERIALS AND METHODS: This retrospective, longitudinal observational study was performed in outpatients with diabetes mellitus who visited our hospital between April 2019 and March 2020 (pre‐COVID‐19 period) and continued for follow up from April 2020 to March 2021 (COVID‐19 period). We compared the glycemic control, nutritional intakes, and body composition of people with diabetes mellitus between the two periods. The changes in the HbA1c values (ΔHbA1c) and other study variables were compared between the two periods. Logistic regression analysis was performed to identify the factors associated with the increase of HbA1c levels. RESULTS: A significant increase of HbA1c was observed during the COVID‐19 period. The percent fat mass (FM) also increased, while the percent skeletal muscle mass (SMM) decreased during the COVID‐19 period. After adjustments for age and sex, the ΔBMI (OR:2.33), ΔFM (OR:1.45), and ΔSMM (OR:0.51) were identified as being associated with elevated levels of HbA1c. CONCLUSIONS: The COVID‐19 pandemic had a negative impact on the glycemic control and body composition of people with diabetes mellitus. The increased body weight and FM and decreased SMM observed during the pandemic were associated with poor glycemic control in people with diabetes mellitus.