using intermittently scanned continuous glucose monitoring (isCGM) to clarify the characteristics of blood glucose variability parameters in T2DM patients with NCP, guide the formulation of reasonable clinical treatment measures and make timely and reasonable adjustments, improve the prognosis of patients, shorten the length of hospital stay, and reduce medical costs. The goal of this observational study is to investigate the characteristics of blood glucose variability in patients with type 2 diabetes mellitus (T2DM) complicated with novel coronavirus pneumonia (NCP) and its effect on disease progression and prognosis. The main question it aims to answer is:After fully lifting coronavirus disease 2019 (COVID-19) pandemic control measures in mainland China in 12/2022, the incidence of COVID-19 has increased markedly, making it difficult to meet the general time-in-range (TIR) requirement. Therefore, the investigators investigated a more clinically practical TIR threshold and examined its association with the prognosis of COVID-19 patients with type-2 diabetes. participant population/health conditions：Participants were equipped with isCGM sensors on admission. According to the outcome, the patients were divided into favorable outcome group and composite outcome group.