This report presents the recent prevalence and comorbidities related to diabetes in Korea by analyzing the nationally representative data.
Using data from the Korea National Health and Nutrition Examination Survey for 2013 to 2014, the percentages and the total number of subjects over the age of 30 years with diabetes and prediabetes were estimated and applied to the National Population Census in 2014. Diagnosis of diabetes was based on fasting plasma glucose (≥126 mg/dL), current taking of antidiabetic medication, history of previous diabetes, or glycosylated hemoglobin (HbA1c) ≥6.5%. Impaired fasting glucose (IFG) was defined by fasting plasma glucose in the range of 100 to 125 mg/dL among those without diabetes.
About 4.8 million (13.7%) Korean adults (≥30 years old) had diabetes, and about 8.3 million (24.8%) Korean adults had IFG. However, 29.3% of the subjects with diabetes are not aware of their condition. Of the subjects with diabetes, 48.6% and 54.7% were obese and hypertensive, respectively, and 31.6% had hypercholesterolemia. Although most subjects with diabetes (89.1%) were under medical treatment, and mostly being treated with oral hypoglycemic agents (80.2%), 10.8% have remained untreated. With respect to overall glycemic control, 43.5% reached the target of HbA1c <7%, whereas 23.3% reached the target when the standard was set to HbA1c <6.5%, according to the Korean Diabetes Association guideline.
Diabetes is a major public health threat in Korea, but a significant proportion of adults were not controlling their illness. We need comprehensive approaches to overcome the upcoming diabetes-related disease burden in Korea.
The global estimated number of people with diabetes was 415 million (8.8%) among subjects aged 20 to 79 years in 2015, and it is expected to rise by 54.7%, to 642 million (10.4%) in 2040, according to the International Diabetes Federation (IDF) atlas 2017 [
With recognition of the rising burden of diabetes in Korea, the Korea Diabetes Association (KDA) published diabetes fact sheets in 2012, 2013, 2015, and 2016 (infographics are available at
This study analyzed data from the sixth (2013 to 2014) KNHANES. Among 15,568 participants (7,030 men and 8,538 women), 10,595 subjects aged 30 years or older were included in our final analyses (
KNHANES data also include a standardized health interview assessing the prior history of diagnosis of diabetes, hypertension, or hypercholesterolemia and medication for those conditions. After overnight fasting, plasma glucose, total cholesterol, high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG), serum and urinary concentration of creatinine were measured using a Hitachi Automatic Analyzer 7600 (Hitachi, Tokyo, Japan). Low density lipoprotein cholesterol (LDL-C) was measured by direct assay in persons with TG >200 mg/dL (Hitachi Automatic Analyzer 7600; Hitachi, Tokyo, Japan; KNHANES 2012 to 2014). Thus, we used either directly measured or calculated LDL-C according to the Friedewald calculation: LDL-C=total cholesterol−HDL-C−(TGs/5) [
Diagnosis of diabetes was based on fasting plasma glucose (FPG, ≥126 mg/dL), current taking of antidiabetic medication(s), history of previous diabetes, or HbA1c ≥6.5%. Impaired fasting glucose (IFG) was defined by FPG in the range of 100 to 125 mg/dL among those without diabetes as defined above [
The estimated population of diabetes in Korean adults (≥30 years of age) is 4.8 million, which represented 13.7% of this group in 2013 to 2014 (
The prevalence of obesity and abdominal obesity in Korean adults with diabetes was 48.6% and 58.9%, respectively (
Among adults with diabetes (previously and newly diagnosed at this survey), 70.7% were aware of their condition and 63.0% were in treatment. Most adults with previously diagnosed diabetes were treated with oral hypoglycemic agents (80.2%), while 8.9% were treated with insulin with or without an oral hypoglycemic agent; 10.8% were maintained without pharmacologic treatment. The control rate among those with previously diagnosed diabetes was 23.3% for a target goal of HbA1c <6.5% or 43.5% for <7%. Fourteen point six percent (14.6%) of Korean diabetic adults remained above 9.0% of HbA1c (
Since 2012, the KDA has been working with the KCDC to derive regular statistics for the diabetes fact sheets in Korea [
Among Koreans ≥30 years of age, 15.7% of men and 11.9% of women had diabetes. Of older people (≥65 years of age), 30.4% had diabetes. The highest prevalence was among those aged 60 to 69 years old (33.1%) in men and ≥70 years old in women (33.8%), which is consistent with global age-specific prevalence figures of diabetes provided by the IDF [
Type 2 diabetes mellitus is associated with clustered risk factors for cardiovascular diseases (CVDs) [
Previously, data from the health insurance claims database of Korea NHIS showed that the prevalence of type 2 diabetes mellitus among adults aged ≥30 years, based on the claim history for antidiabetic medications in subjects with International Classification of Diseases 10th (ICD-10) codes E11-E14, increased from 5.6% to 8% from 2006 to 2013 [
Thus, our analysis, based on the natinal level health examination survey data, would be representative of the nationwide prevalence of diabetes in Koreans. However, our study has some limitations. First, it is difficult to prove that those studies and this one correlate, because this study is a cross-sectional, descriptive study, and we provided the actual estimated data rather than statistical powers to analyze or compare these estimates to prove the relationship between variables or the comparison between subjects with and without diabetes or different data sets. Second, most estimations of our variables were carried out by self-reported questionnaires and face-to-face interviews, which always implies the possibility of recall bias. However, there was a high concordance between the self-administered questionnaire and the actual measurement of diabetes (κ=0.82) in the KNHANES [
Although accumulating evidence has suggested that the importance of glycemic control and availability of newly developed antidiabetic treatment has increased over the past few decades, the control rate of diabetes (defined by HbA1c <6.5%) in Korean adults remains unsatisfactory between 2005 (22.9%) and 2014 (23.3%) [
Diabetes continues to be a major public health threat in Korea, affecting one in seven adults. However, a significant proportion of the adult population is not controlling their illness. It is critical to monitor this situation continuously through nationally representative data and to establish a program for the prevention of diabetes and its related comorbidities to reach the nation's urgent goals.
Demographic and clinical characteristics of 10,595 subjects aged 30 years or older
Variable | Diabetes | Impaired fasting glucose | ||||
---|---|---|---|---|---|---|
Total | Men | Women | Total | Men | Women | |
By age group, yr | ||||||
≥30 | 13.7 (4,810) | 15.7 (2,580) | 11.9 (2,230) | 24.8 (8,259) | 29.6 (4,786) | 20.1 (3,473) |
≥65 | 30.4 (1,951) | - | - | 26.6 (1,684) | - | - |
30–39 | 3.1 (124) | 2.1 (80) | 20.0 (796) | 11.2 (425) | ||
40–49 | 12.1 (521) | 5.7 (239) | 31.4 (1,354) | 16.9 (708) | ||
50–59 | 18.8 (748) | 11.1 (442) | 37.9 (1,511) | 26.2 (1,042) | ||
60–69 | 33.1 (729) | 24.1 (574) | 30.3 (668) | 26.9 (642) | ||
≥70 | 27.2 (457) | 33.8 (895) | 27.1 (457) | 24.4 (657) | ||
By family incomes (quartiles)a | ||||||
Quartile 1 | 15.1 | 17.7 | 12.6 | 22.4 | 27.0 | 17.8 |
Quartile 2 | 12.8 | 14.7 | 10.6 | 24.2 | 28.1 | 20.4 |
Quartile 3 | 11.7 | 13.3 | 10.2 | 24.6 | 29.2 | 20.3 |
Quartile 4 | 11.2 | 13.4 | 9.2 | 23.2 | 29.7 | 16.9 |
Values are presented as percentage (number) and percentage.
aFrom the lowest to the highest.
Variable | Current smoking | High-risk drinking | Regular walking exercise |
---|---|---|---|
Total | |||
≥30 yr | 27.4 | 14.3 | 21.9 |
≥65 yr | 13.7 | 3.7 | 7.6 |
By sex and age group, yr | |||
Men | 44.0 | 23.0 | 38.3 |
30–39 | 61.8 | 34.5 | 38.2 |
40–49 | 57.2 | 39.8 | 46.4 |
50–59 | 46.2 | 25.5 | 32.7 |
60–69 | 41.6 | 14.6 | 18.5 |
≥70 | 18.7 | 7.5 | 12.6 |
Women | 5.2 | 2.6 | 37.3 |
30–39 | 20.2 | 7.8 | 11.1 |
40–49 | 1.5 | 7.5 | 11.5 |
50–59 | 6.0 | 4.3 | 6.9 |
60–69 | 6.3 | 0.0 | 0.0 |
≥70 | 3.0 | 1.2 | 3.9 |
Values are presented as percentage.
Variable | Hypertension | Hypercholesterolemia | Nephropathy | ||||
---|---|---|---|---|---|---|---|
Prevalence | Treatment rate | Prevalence | Treatment rate | Albuminuria | CKD | Total | |
Total | |||||||
≥30 yr | 54.7 | 69.1 | 31.6 | 49.8 | 23.9 | 12.5 | 30.3 |
≥65 yr | 71.7 | 76.6 | 31.7 | 51.0 | 26.1 | 23.1 | 39.0 |
By sex and age group, yr | |||||||
Men | |||||||
30–39 | 15.8 | 81.3 | 40.4 | 46.9 | 8.7 | 4.7 | 8.7 |
40–49 | 43.2 | 44.9 | 26.6 | 44.7 | 28.0 | 0.9 | 28.9 |
50–59 | 51.0 | 55.9 | 28.7 | 59.9 | 24.1 | 11.8 | 28.5 |
60–69 | 58.9 | 74.5 | 29.8 | 54.0 | 26.0 | 13.7 | 35.6 |
≥70 | 66.9 | 77.7 | 17.7 | 51.7 | 33.5 | 32.5 | 52.5 |
Women | |||||||
30–39 | 7.8 | 92.2 | 42.1 | 32.2 | 23.2 | - | 23.2 |
40–49 | 24.2 | 73.6 | 19.6 | 34.1 | 22.6 | 3.8 | 22.6 |
50–59 | 42.3 | 79.9 | 35.5 | 43.1 | 18.7 | 3.5 | 19.5 |
60–69 | 70.6 | 76.6 | 44.9 | 49.1 | 21.0 | 11.4 | 25.5 |
≥70 | 78.1 | 72.4 | 37.0 | 49.1 | 20.7 | 22.9 | 34.5 |
Values are presented as percentage.
CKD, chronic kidney disease.
Variable | Awareness | Treatment | Comprehensive management | |
---|---|---|---|---|
<6.5 | <7.0 | |||
Total | ||||
≥30 yr | 70.7 | 63.0 | 9.4 | 16.8 |
≥65 yr | 85.2 | 77.6 | 12.0 | 22.0 |
By sex and age group, yr | ||||
Men | ||||
30–39 | - | - | 18.6 | 29.7 |
40–49 | 46.0 | 32.9 | 7.0 | 8.0 |
50–59 | 65.5 | 59.3 | 7.9 | 14.9 |
60–69 | 78.4 | 72.2 | 9.0 | 19.5 |
≥70 | 82.0 | 73.6 | 15.0 | 26.0 |
Women | ||||
30–39 | - | - | 13.4 | 13.4 |
40–49 | 56.9 | 52.8 | 5.6 | 9.1 |
50–59 | 68.7 | 59.7 | 5.6 | 13.1 |
60–69 | 81.5 | 75.6 | 10.7 | 16.9 |
≥70 | 87.4 | 80.8 | 10.3 | 20.9 |
Values are presented as percentage.
aComprehensive management included treatment of hyperglycemia, hypertension, and hypercholesterolemia.