Does pre-existing diabetes correlate with long COVID-19 in Europe? Evidence from the analysis of the survey of health, ageing and retirement in Europe’s Corona surveys

Abstract

Background. A substantial proportion of those infected with COVID-19 are presenting with persistent symptoms, referred to as long COVID-19. Emerging evidence suggests that the presence of pre-existing chronic conditions, such as diabetes, may increase the risk of long COVID-19. Objectives. To investigate whether having pre-existing diabetes increases the risk of developing long COVID-19 in the population of middle-aged and older adults (≥50 years old) in Europe, while assessing if this relationship can be accounted for or is modified by the known long COVID-19 and diabetes risk factors (age, sex, hospitalization, pre-existing hypertension, and weight status). Methods. A population-based longitudinal prospective study involving a sample of respondents aged 50 years and older (n = 4,004) with probable or confirmed COVID-19 infection from 27 countries that participated in both waves 7 and 8 of the Survey of Health, Ageing and Retirement in Europe and its 2020 and 2021 Corona Surveys. Logistic regression modeling was performed. Results. Overall, 66.8% of the respondents affected by COVID-19 infection reported at least one long COVID-19 symptom; 55.2% were female, and the average age was 64.6 years; 13.2% had pre-existing diabetes. Respondents with pre-existing diabetes had significantly higher odds of developing long COVID-19, compared to those without diabetes (OR = 1.37 ; 95% CI = 1.12 , 1.68). This relationship remained significant (OR = 2.00 ; 98% CI = 0.25 , 1.14) after adjusting for sex (OR = 1.64 for females; 95% CI = 1.43 , 1.88), hospitalization for COVID-19 illness (OR = 3.19 ; 95% CI = 2.41 , 4.23), pre-existing hypertension (OR = 1.17 ; 95% CI = 1.01 , 1.36), and overweight (OR = 1.31 ; 95% CI = 1.11 , 1.56) and obese (OR = 1.77 ; 95% CI = 1.44 , 2.19) weight status. The effect of pre-existing diabetes on the risk of long COVID-19 is moderated by age; it was highest at the age of 50 (OR = 2.00 ; 95% CI = 1.28 , 3.14), and then, it declined with age. Conclusions. There is a relationship between pre-existing diabetes and long COVID-19, even after controlling for literature-based confounding factors, with age having a moderating effect on this relationship.