Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Recent eClinical Medicine The study investigates whether people with diabetes are more prone to develop long-term COVID, which is defined as the prolonged persistence of symptoms after infection with SARS-CoV-2.
Study: Prevalence of long-term COVID in people with diabetes mellitus – evidence from a UK cohort. Image credit: Dragana Gordic / Shutterstock.com
What causes long-term COVID?
Long-term COVID has been described as the persistence of symptoms or the development of a multisystem syndrome after recovery from the initial SARS-CoV-2 infection. Some common features of long-term COVID include muscle weakness, difficulty concentrating/brain fog, fatigue, and malaise. Other less common symptoms of long-term COVID are chest pain, headaches, excessive sweating, anxiety, and sore throat.
Although scientists have identified several factors that contribute to the development of long-term COVID, few studies have investigated the prevalence of long-term COVID at the population level. Understanding whether this prevalence varies with a specific comorbidity is essential.
About the study
The current retrospective observational cohort study investigated the prevalence of long-term COVID in the UK population. The researchers were particularly interested in studying people with diabetes, as several studies have confirmed that people with a history of diabetes mellitus are at greater risk of developing adverse consequences of acute SARS-CoV-2 infection.
All relevant electronic health record (EHR) data were obtained from the Greater Manchester Care Record (GMCR). This database hosts the Primary Health Care records of approximately 2.87 million people in Greater Manchester.
The current study investigated whether individuals with type 1 diabetes (T1D) or T2D were susceptible to developing long-lasting COVID after SARS-CoV-2 infection. For this purpose, subjects with a history of T1D or T2D and COVID-19 confirmed by polymerase chain reaction (PCR) testing were considered.
Each participant with T1D or T2D was age- and sex-matched with healthy or non-diabetic controls. Importantly, all study participants tested positive for COVID-19, even 28 days after recovering from the initial infection.
Study findings
A total of 3,087 subjects with T1D were matched with 14,077 non-diabetic controls, while 3,087 subjects with T2D were matched with 14,077 non-diabetic controls. The mean age of people diagnosed with T1D and T2D was 47 and 65, respectively. All patients with T1D were treated with insulin, while those with T2D were treated with insulin and oral hypoglycemic agents.
The researchers hypothesized that people with T2D regularly attend general practices to monitor their condition. This increases the chance of being diagnosed with long-term COVID more effectively.
A lower number of long-term COVID diagnoses or referrals was associated with individuals with T1D at 0.33% compared to 0.48% for matched controls. Compared with men with T2D, matched controls without T2D were less likely to develop long-term COVID.
The prevalence of long-term COVID was higher in matched controls compared to women with T2D. Both men and women with T2D showed a similar prevalence of long-term COVID.
A bidirectional association was observed between long duration of COVID, T2D and acute COVID-19. Those with a higher body mass index (BMI), younger women or of mixed ethnicity who had been diagnosed with T2D were at greater risk of developing long-term COVID.
It is possible that younger women with T2D were more vulnerable to long-term COVID due to the tendency of this group to visit general practices more often than men.
Strengths and limitations
The main strength of the current study is its cohort, which included all general practices in Greater Manchester. In addition, only participants who were accurately diagnosed with diabetes were considered for the analysis. Another strength of this study is the examination of the broad period of the COVID-19 pandemic from its onset to September 2023.
Consistent with previous reports, the current study also recognizes that the diagnosis of long-term COVID is a matter of variability. Although individuals with acute SARS-CoV-2 infection are likely to be indicated, the number of diabetics and non-diabetics has remained stable.
Another limitation is the exclusion of people with other forms of diabetes, such as maturity-onset diabetes of the young (MODY) or secondary to pancreatitis.
Despite these limitations, the current study highlighted that individuals with T2D develop long-term COVID at a higher rate. Therefore, more research is needed to identify the different factors that increase the risk of long-term COVID.
Journal Reference:
- Heald, HA, Williams, R., Jenkins, DA, et al. (2024) Prevalence of long-term COVID in people with diabetes mellitus – evidence from a UK cohort. eClinical Medicine. doi:10.1016/j.eclinm.2024.102607
