More than a quarter of NHS patients who died in hospitals in England after contracting coronavirus had diabetes, figures show.

Of the 22,332 patients who have died in England’s hospitals since March 31, when pre-existing conditions began to be recorded, some 5,873 (26%) had diabetes.

Published on Thursday, it is the first time NHS England has included a breakdown of deaths by pre-existing conditions in its statistics.

Charity Diabetes UK said the figures show an “urgent” need for more information to ensure the safety of those with diabetes as lockdown measures are eased.

While official advice recognises people with diabetes can be more vulnerable to becoming seriously ill with the virus, those with the disease were not included in a group told to “shield” themselves by staying at home.

Data published by NHS England does not specify whether those who died had type 1 and type 2 diabetes.

The health service said the accuracy of the data is reliant on the availability and transfer of information by healthcare providers, and patients may have had more than one pre-existing condition.

Bridget Turner, director of policy at Diabetes UK, said: “The fact that more than a quarter of people who have died with Covid-19 have diabetes underlines the urgent need to ensure better protection and extra support is available to those in the clinically vulnerable groups.

“We also need urgent action from government to understand the detail behind this figure, including diabetes type, age, ethnicity, medical history and comorbidities of those who have sadly died, so that we can know how to keep all people with diabetes safe.

“Government must ensure urgently that employers take all the necessary measures to keep employees with diabetes safe, if they are expected to attend work outside the home as restrictions are eased.”

Further data analysis on diabetes – carried out based on type, ethnicity, control and weight – is expected to be published shortly.

Tam Fry, of the National Obesity Forum, said: “We have known since the swine flu pandemic of 2009 that viral diseases prey on the obese and, from Covid-19 statistics, that if you are obese you have double the risk of needing intensive care treatment.

“Obesity is a major cause of type 2 diabetes.”

Professor Partha Kar, national speciality adviser for diabetes for NHS England, said: “It is clear that people with diabetes are more at risk of dying from Covid-19 and more detailed analysis is currently under way to understand the link between the two, although initial findings indicate that the threat in people under 40 continues to be very low.

“The NHS has put extra measures in place so that people living with diabetes can manage their condition better during the pandemic, including a range of online services, video consultations with your local clinical team and a dedicated helpline for those who need advice.”

Meanwhile, the data also shows that some 4,048 (18%) of those who died in hospitals in England since March 31 had dementia.

Some 3,254 (15%) were reported to have chronic pulmonary disease while 1,549 patients had asthma.

In response to the figures that almost one in five of all people who died with the virus had dementia, Alzheimer’s Research UK said it may be due to high rates of infection in care homes.

Samantha Benham-Hermetz, director of policy and public affairs at the charity, said: “Age is the biggest risk factor for dementia, and with older people also more likely to experience severe symptoms from Covid-19, this may partly explain the high number of deaths.

“It is also possible that people with dementia may be more likely to have been exposed to the virus due to high rates of infection in care homes.

“As a matter of priority, Government must protect people with dementia and more research is needed to understand why people with dementia are so badly affected by Covid-19, so that the right measures can be put in place to prevent further deaths.”

It comes as NHS England announced 207 new deaths of people who tested positive for Covid-19, bringing the total number of confirmed reported deaths in hospitals in England to 24,159.