Trends in diabetes prevalence among Korean adults based on Korean National Health and Nutrition Examination Surveys III-VI

Aims: The purpose of this study was to investigate trends in diabetic prevalence over the past 11 years using Korea National Health and Nutrition Examination Survey (KNHANES) data. In addition, we aimed to examine trends in diagnosed and undiagnosed diabetes after stratification.

Methods: We used data from the KNHANES III (2005), IV (2007-2009), V (2010-2012), and VI (2013-2015). 46,157 participants were included in this study. Diabetes was defined as follows: (1) an answer of 'yes' to whether the participants had ever been diagnosed with diabetes by a physician, (2) fasting plasma glucose (FPG) ≥126 mg/dL, or (3) taking oral hypoglycemic agents or insulin. All sampling and weight variables were stratified, and analysis to account for the complex sampling design. The prevalence of diabetes was standardized by the 2005 Korean Housing Census.

Results: In men, the crude prevalence of total and undiagnosed diabetes were significantly increased with KNHANES phase (P for trend = 0.002 and 0.004, respectively). The age-standardized prevalence of total, diagnosed and undiagnosed diabetes of both sexes increased with the KNHANES phase (all P for trend < 0.001). Compared with the KNHANES III, the age-adjusted odds ratios (ORs) for the crude-prevalence of undiagnosed diabetes in KNHANES IV, V, and VI were 1.00 (0.72-1.41), 1.08 (0.78-1.51), and 1.42 (1.04-1.96) for men.

Conclusions: The prevalence of total, diagnosed and undiagnosed diabetes steadily increased and public efforts should focus on screening for the detection of diabetes, especially in men.