August 27, 2020

Hyperglycemia, underweight or obesity and previous cardiovascular and renal complications could put people with diabetes at higher risk for COVID-19-related death, according to a study published in The Lancet Diabetes Endocrinology.

“Diabetes, cardiovascular disease and hypertension are the most common chronic comorbidities in people with severe COVID-19,” Jonathan Valabhji, BSc, MBBS, MD, FRCP, national clinical director for diabetes and obesity at National Health Service (NHS) England and NHS Improvement, and colleagues wrote. “In a companion study, we showed that, compared with individuals without diagnosed diabetes, the odds ratios for dying in hospital with COVID-19 were 3.51 (95% CI, 3.163.9) in people with type 1 diabetes and 2.03 (95% CI, 1.972.09) in people with type 2 diabetes. However, in this companion study, it was not possible to adjust for hypertension, chronic kidney disease, BMI and tobacco smoking status, due to limitations in the datasets used for the whole population.”

Researchers conducted a population-based cohort study of people with diabetes in England using data linked to national death registries to assess COVID-19 mortality rates. Data from the National Diabetes Audit included information such as age, socioeconomic status and ethnicity. The most recent HbA1c and glomerular filtration rates recorded in 2019 were included in the data, as well as the most recent BMI and smoking status from 2017 2019. Information on myocardial infarction, stroke and heart disease was recorded from Hospital Episode Statistics records from April 2017 December 2019.

Comparisons between the mean number of deaths the previous 3 years among people with type 1 and type 2 diabetes and statistics within the first 19 weeks of 2020 showed an increase in deaths beginning in mid-March. Deaths among people with type 1 diabetes increased 50.9%, and deaths for people with type 2 diabetes were up 64.%.

Between Feb. 16 and May 11, 464 people with type 1 diabetes had COVID-19 included on their death certificate of 1,604 all-cause deaths, and 10,525 people with type 2 diabetes were considered to have died from COVID-19 of 36,291 all-cause deaths.

Diabetes risk factors

People with type 1 diabetes (HR = 2.23; 95% CI, 1.5-3.3) and type 2 diabetes (HR = 1.61; 95% CI, 1.47-1.77) with an HbA1c of 10% or higher had a significantly greater risk for COVID-19-related mortality than those with an HbA1c between 6.5% and 7%, with the risk increasing for people with type 2 diabetes as HbA1c increased.

“Hyperglycemia is known to impair host defenses, including granulocyte and macrophage function. People with diabetes are at increased risk of many serious infections,” researchers wrote. “Poor glycemic control has been associated with serious infections and hospital admission and has been hypothesized to amplify the hyperimmune response associated with severe COVID-19.”

Low and high BMI were both associated with an increased risk for COVID-19-related mortality in people with type 1 and type 2 diabetes. People with type 1 diabetes saw the highest risk for COVID-19 death with a BMI of less than 20 kg/m² (HR = 2.45; 95% CI, 1.6-3.75) and more than 40 kg/m² (HR = 2.33; 95% CI, 1.53-3.56). People with type 2 diabetes similarly saw an elevated risk with a BMI of less than 20 kg/m² (HR = 2.33; 95% CI, 2.11-2.56) and more than 40 kg/m² (HR = 1.6; 95% CI, 1.47-1.75).

Previous , stroke, heart failure or impaired renal function was found in 62.3% of people withtype 1 diabetes who died from COVID-19 and 55.4% of people with type 2 diabetes.

“Although several risk factors identified for COVID-19-related mortality in people with diabetes cannot readily be modified, HbA1c can be improved by healthcare intervention,” researchers wrote. “Although the association with obesity was more complex, particularly in the type 2 diabetes population, bodyweight can also be affected by healthcare interventions — a goal of routine care. Improved achievement of standard diabetes care recommendations that target prevention of cardiovascular and microvascular complications would also serve to modify some of the risk factors that we have shown to be associated with COVID-19-related mortality.”

Current smokers with type 2 diabetes had a lower risk for COVID-19 mortality than nonsmokers (HR = 0.67; 95% CI, 0.62-0.74); however researchers said more research on the association between smoking and COVID-19 is needed.

“The unexpected finding with regard to current smoking status should not be taken to imply that tobacco smoking is protective of COVID-19 and might be the result of confounding by as yet unidentified factors or collider bias,” researchers wrote. “Other studies have shown that, among people with diagnosed COVID-19, smokers have poorer outcomes.”

Demographic risk factors

Demographic data showed men had a higher risk for COVID-19-related mortality than women with type 1 (HR = 1.61; 95% CI, 1.32-1.96) and type 2 diabetes (HR = 1.61; 95% CI, 1.54-1.67). People with type 1 and type 2 diabetes also had a higher risk for COVID-19 death at age 70 or older (P < .0001) compared with those aged 60 to 69 years.

Among those with type 1 diabetes, Black (HR = 1.77; 95% CI, 1.25-2.49) and Asian people (HR = 1.57; 95% CI, 1.16-2.12) both had higher risks for COVID-19 mortality than white people. The same trend held for people with type 2 diabetes, with Black (HR = 1.63; 95% CI, 1.51-1.77) and Asian people (HR = 1.08; 95% CI, 1.01-1.15) demonstrating an elevated risk.

Those considered most deprived in the study’s socioeconomic index were at highest risk for COVID-19 mortality with both type 1 (HR = 1.93; 95% CI, 1.36-2.72) and type 2 diabetes (HR = 1.46; 95% CI, 1.37-1.56). The risk for COVID-19-related mortality decreased as socioeconomic status improved.

Link to Original Article