Does glucose control influence outcomes for patients with COVID-19 and type 2 diabetes?

This study looked at the outcomes of patients with type 2 diabetes (T2D) who were diagnosed with COVID-19. It found that patients with well-controlled blood glucose had fewer medical interventions and notably better survival.

COVID-19 is a highly infectious coronavirus that emerged in the Hubei province of China in late 2019. Symptoms of COVID-19 include fever and difficulty breathing, although some patients do not have symptoms. COVID-19 may result in respiratory failure or organ failure. Patients with severe COVID-19 may need to have a tube placed down the windpipe so that a ventilator machine can breathe for them. Patients with pre-existing conditions, including T2D, are more likely to have poor outcomes from COVID-19.

High blood glucose levels from T2D lead to inflammation, and worse outcomes during infections and viral illnesses. However, well-controlled blood glucose raises the risk of hypoglycemia (dangerously low blood glucose), which also increases the risks from this infection. It is unclear how glucose control influences the outcomes of COVID-19 infection for patients with T2D.

This study included medical records from 7,337 patients treated for COVID-19 at nineteen hospitals in Hubei Province, China. The patients included were between 18 and 75 years old. They did not have other medical conditions including cancer and pregnancy. 952 patients (13.0%) had pre-existing T2D.

Compared with other patients, patients with T2D more often had other pre-existing conditions including high blood pressure (53.4% vs. 19.7%) and kidney disease (4.9% vs. 1.3%). Patients with T2D more often had blood tests showing increased inflammation. Patients with T2D required more medical interventions during treatment for COVID-19, including antibiotics (61.3% vs. 56.9%) and oxygen therapy (76.9% vs. 61.2%). Patients with T2D more often had to be put on a mechanical ventilator (3.6% vs. 0.7%).

282 of the patients with T2D had well-controlled glucose levels (between 3.9 and 10.0 mmol/L). 528 patients had poorly controlled glucose levels (highest measurement above 10.0 mmol/L). The two groups had similar ages and body weights. Fewer of the patients with well-controlled glucose had low lymphocyte blood cell levels (30.5% vs. 49.6%) and inflammation (high C-reactive protein 47.5% vs. 59.5%). Patients with T2D and well-controlled glucose had significantly higher survival rates (by 86%) compare to those with poor blood glucose control.

This study found that patients with well-controlled glucose had markedly better outcomes from COVID-19 than other patients with T2D.

Outcomes of COVID-19 have varied by country and region. The researchers were not able to obtain pre-hospital patient records or to determine whether blood glucose control changed after COVID-19 infection.

Talk to your healthcare provider about whether the COVID-19 pandemic affects your diabetes management plan.