The research, led by a team at City St George’s, University of London and adopted by NIHR ARC South London, also aimed to find out whether improved blood sugar level control affects the risks of infection. 

People living with diabetes often develop infections which affect quality of life and can lead to hospital admission. However, diabetes guidelines do not emphasise this aspect of care and although lower long-term blood sugar (HbA1c) levels reduce infection risk, little is known about how fluctuations in blood sugar levels affect the risk of infection. 

Our research found that people with Type 1, Type 2 diabetes or prediabetes are at greater risk of infections than patients without diabetes. Most notably, young people with either Type1 or Type 2 diabetes had higher infection risks then older patients with diabetes. People from non-white ethnic backgrounds with Type 1 diabetes, also had higher infection risks than white patients with Type 1 diabetes. We need greater awareness, recognition and treatment of infections in primary care in patients with diabetes.

Tess Harris, professor of primary care research, City St George’s, University of London

World diabetes day 2024

The research team used routinely collected English GP data, linked to hospital admissions, including patients aged 18-90 from 2015 to 2019. There were approximately 34,000 Type 1 Diabetes (T1D) patients, 527,000 Type 2 diabetes (T2D) patients, 273,000 pre-diabetes patients and a million patients without diabetes / prediabetes for comparison. 

The research found compared to patients without diabetes:

  • T1D patients were twice as likely to have a primary care infection and three and a half times as likely to have a hospital admission for infection. 
  • T2D patients were one and a half times as likely to be treated for a primary care infection and twice as likely to be treated in hospital for infection. 
  • Even prediabetes patients had an increased risk, they were one and a third times as likely to have in infection treated in either primary care or hospital. 
  • In both T1D and T2D those at younger ages had higher infection risks. 
  • Whilst in T1D all those of non-white ethnicities had higher infection risks
  • In T2D and prediabetes infection risk was similar across all ethnic groups. 
  • In T1D and T2D having a high blood sugar level and a blood sugar level that varied a lot both increased infection risk, in T1D high level was most important, whereas in T2D variability was most important. 

Infections are an important burden for patients living with T1D, T2D and prediabetes, future diabetes guidelines need to better reflect this. Reducing both long-term blood sugar levels and variability may reduce infections. It is important for patients to have prompt access to and treatment of infections in primary care, particularly for vulnerable groups which could reduce hospital admissions

Julia Critchley, professor of epidemiology, City St George’s, University of London

The research team worked with a Patient Advisory Group who had lived experience of diabetes from the outset of the research and has brought tangible benefits. Some of the key themes patients discussed include: 

  • Spreading the message about the important of early treatment of infections in diabetes to the whole primary care system, not just the clinical teams
  • Difficulties accessing regular HbA1c (blood sugar) tests – which NICE recommends should be 6-monthly, most were only offered annually, unless unwell or after medication changes
  • Great variation in GP surgeries in ease of access to treatment for infections, accessing test results and discussing these results with a trusted healthcare professional.

The Patient Study Advisory Group are working with the research team to disseminate the research to diabetes patient groups, South-East and South-West London Integrated Care Systems and Diabetes UK. The study team will also share the research with national health organisations to inform policy. 

 

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Published papers

Effects of long-term HbA1c variability on serious infection risks in patients with type 2 diabetes and the influence of age, sex and ethnicity: A cohort study of primary care data

A matched cohort study evaluating the risks of infections in people with type 1 diabetes and their associations with glycated haemoglobin

Evaluating Ethnic Variations in the Risk of Infections in People With Prediabetes and Type 2 Diabetes: A Matched Cohort Study

ARC Adopted project: People living with diabetes and intermediate hyperglycaemia: risk of infections in people from different ethnic groups