A National trends in type 2 diabetes in South Korea, including the COVID-19 pandemic, 1998-2021: A nationally representative survey study

Objective: The COVID-19 pandemic has been associated with worse outcomes for people with diabetes, including increased mortality, while the long-term impact of the pandemic on diabetes prevalence is still underestimated. Thus, we aimed to analyze long-term prevalence trends of type 2 diabetes in South Korea from 1998 to 2021, encompassing the before and during the pandemic. Methods: This study utilized data from the Korea National Health and Nutrition Examination Survey to investigate changes in diabetes prevalence and associated factors from 1998 to 2021, including during the pandemic. We focused on adults aged 30 years and older and evaluated weighted odds ratios or weighted beta coefficients for these factors across various categories, including age, sex, region of residence, education level, household income, smoking status, and body mass index group. Results: From 1998 to 2021, the overall prevalence of diabetes increased from 5.61% (95% CI, 5.36–5.86) in 1998–2005 to 10.61% (95% CI, 9.50–11.72) in 2020 and 11.61% (95% CI, 10.36–12.86) in 2021, indicating no significant change due to COVID-19 (βdiff, 0.030; 95% CI, -0.039 to 0.099). Groups vulnerable to diabetes included older populations, male sex, rural residents, those with lower education and income, smokers, and those who were obese or overweight. Conclusions: Our study found a consistent increase in the prevalence of diabetes yearly, including during the pandemic, with higher risks in older individuals, male sex, rural residents, those with lower education levels and lower household income levels, smokers, and those who were overweight/obese.