National trends in type 2 diabetes mellitus stratified by central adiposity using waist-to-height ratio in South Korea, 2005–2022

Studies investigating the association between type 2 diabetes mellitus and central adiposity are lacking. Therefore, this study aimed to investigate trends in type 2 diabetes mellitus stratified by central adiposity using waist-to-height ratio (WHtR). Trends in type 2 diabetes mellitus were examined by central adiposity, using WHtR, with data from the Korea National Health and Nutrition Examination Survey (2005-2022). Individuals aged 30 years and over who participated in the survey were selected. Type 2 diabetes mellitus was identified based on serum glucose or HbA1c levels, the use of diabetes medications, or a prior diagnosis by a physician. Weighted β-coefficients or odd ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess changes in disease prevalence. A total of 79,368 participants were included in the database (female: 45,163 [56.9%]). from 2005 to 2022, the prevalence of type 2 diabetes mellitus increased from 3.3 to 5.8% in the healthy central adiposity group, from 11.2 to 17.1% in the increased central adiposity group, and from 18.0 to 26.7% in the high central adiposity group. Males, older population, lower education level, lower household income, and smoking are associated with a higher risk of type 2 diabetes. In the high central adiposity group, overweight and obese individuals had higher susceptibility than underweight or normal-weight individuals, with ORs of 5.85 (95% CI, 2.54-13.47) and 8.24 (3.79-17.94), respectively. The prevalence of type 2 diabetes mellitus has increased in all central adiposity groups in the past decade. This underscores the need for tailored interventions to address disparities and improve diabetes management in at-risk populations.