July 10, 2020

expert reaction to study looking at blood sugar level and death in hospitalised COVID-19 patients in Wuhan

Research, published in Diabetologia, looked at blood sugar level and death in hospitalised COVID-19 patients in Wuhan.

Prof Naveed Sattar, Professor of Metabolic Medicine, University of Glasgow, said:

“This is a nice report but it is fully in line with expectations – we know for example that those with higher blood sugar levels will have more severe disease, because more severe disease will stress metabolic pathways more, leading sugar levels to rise in the sickest patients.  What the authors cannot confirm is whether differential targeting of blood sugar levels in those admitted leads to differences in outcomes.  It would be a step too far to assume from this study that targeting blood sugar more aggressively to lower levels than currently practiced in hospitalised patients would make a difference.  Doctors are already testing sugar levels in such patients so this is not new either but whether these levels help determine outcomes when more clinical data are factored in, is also not certain.  Also, some at risk of diabetes may be pushed into diabetes for a short period by the extreme inflammation in this condition, and what would be interesting is the extent to which their sugar levels improve / revert back to a non-diabetes levels, once they overcome the disease, in those that do.”

Dr David Strain, Senior Clinical Lecturer, University of Exeter Medical School, said:

“This is robust science, which replicates an earlier study in US patients, that also concluded that higher blood sugar levels indicate a greater risk of decline from COVID-19.  Coronavirus attacks ACE2 receptors in the pancreas, on cells that produce the insulin that regulates our blood sugar.  A high sugar level is simply an indicator that there is widespread infection in the whole body.  As a clinician working on covid wards, we routinely check blood glucose levels every morning.  We recognised early on that a rising glucose is a strong predictor of imminent decline irrespective of pre-existing diabetes, and allowed us to prepare for early ventilation or transfer to intensive care units .”

Dr Bernard Khoo, Senior Clinical Lecturer in Endocrinology, UCL, said:

“This interesting study looked at factors that might predict the acute mortality from COVID-19 in patients admitted to major hospitals in Wuhan, China.  It is a retrospective study and appears to have been conducted well with a reasonably large study population.

“Previous studies had shown that diabetes was a risk factor for death in COVID-19.  The key new message from this is that in patients with COVID-19 without previously known diabetes, the presence of elevated fasting blood glucose levels is an independent risk factor for death.  The authors suggest that hormonal factors such as cortisol may be responsible for this elevation in blood glucose levels, and indeed we do know that cortisol itself is a risk factor for acute mortality.  The presence of high blood glucose is a marker of physiological stress and is likely to identify the population of patients with more severe disease.  Another possible mechanism is that the virus infection itself is affecting insulin production from the pancreas, but this study cannot distinguish between the two causes.

“There are limitations to this study.  In particular, we cannot say from this study that some of the patients may have had diabetes but not known that they had it.  Although the authors speculate that controlling blood glucose with intensive treatment may improve outcomes, this study does not show this and indeed the evidence for such a strategy in critically ill patients is mixed.  This will require a randomised controlled trial.”

All our previous output on this subject can be seen at this weblink:

www.sciencemediacentre.org/tag/covid-19

‘Fasting blood glucose at admission is an independent predictor for 28-day mortality in patients with COVID-19 without previous diagnosis of diabetes: a multi-centre retrospective study’ by Sufei Wang et al. was published in Diabetologia at 23:01 UK time on Friday 10 July 2020.

DOI: 10.1007/s00125-020-05209-1

Declared interests

None received.