Influence of Emergency Declaration Over Coronavirus Disease 2019 on Plasma Glucose Control of Patients With Diabetes Mellitus

COVID-19 pandemic poses problems that not only concern the economy but also the health of people all over the world. In Japan, despite the declaration of a “state of emergency”, no lockdown was implemented, and a request for self-restraint and avoidance of non-essential trips was instead issued. After a month, the state of emergency was lifted. Because patients with diabetes mellitus (DM) were forced to stay during the state of emergency, resulting in a lack of physical activity, concerns about their glycemic control were raised. Therefore, glycated hemoglobin (HbA1c) levels during different time periods were compared (May 2018, March 2019, June 2019, July 2019, May 2019, March 2020, June 2020, July 2020). We analyzed 165 patients with DM. The mean age of subjects was 67.8 + 11.5 years. Male comprised 67.3% of the participants. The mean body weight was 65.6 + 14.6 kg on July 2019 and 66.1 + 15.2 kg on July 2020. The mean body mass index (BMI) was 24.4 + 3.6 kg/m(2) on July 2019 and 24.4 + 3.6 on July 2020. Patients with Type 2 DM (T2DM) comprised 90% of the participants, while the rest had T1DM. Mean duration of DM was 12.0 + 7.4 years. In order to assess the effect of the self-restraint on plasma glucose control, HbA1c levels during these periods were compared: May 2018, March 2019, June 2019, July 2019 (one year before COVID-19 pandemic.), and May 2019, March 2020, June 2020, July 2020 (The last three months during COVID-19). March 2020 is corresponded to a period before the request for self-restraint, while June and July 2020 corresponded to the periods right after the end of self-restraint. We also compared HbA1c levels between May 2019 and July 2020 using the Self-Monitoring of Blood Glucose (SMBG) to assess whether SMBG affected plasma glucose control during the period of self-restraint. HbA1c levels in May 2018, March 2019, June 2019, July 2019, May 2019, March 2020, June 2020, July 2020, were 7.32 + 1.23, 7.44 + 1.20, 7.16 + 1.06, 7.01 + 1.05, 7.23 + 1.06, 7.45 + 1.18, 7.15 + 10.7, and 7.11 + 1.17, respectively. Similarly, HbA1c levels between May 2019 without SMBG and May 2019 with SMBG were not statistically different. In this clinical study, we found that the request to avoid non-essential trips as a form of self-restraint during the country’s state of emergency did not affect plasma glucose control of patients with DM. We noted that the patients did not have signs of insulin resistance as their BMI on July 2019 and July 2020 were 24.4 + 3.6 and 24.4 + 3.6, respectively. Unexpectedly, the HbA1c levels were not affected by the absence or presence of SMBG. This could explain why HbA1c levels were not elevated, despite a temporarily sedentary lifestyle and a lack of exercise for a month. In addition, due to the self-restraint, the frequency of dining outside the house decreased, which could have contributed to the non-elevation of HbA1c levels.