We aimed to estimate the threshold level of glycosylated hemoglobin (HbA1c) for the fasting plasma glucose of 100 and 126 mg/dL in the Korean adult population, using the 2011 Korea National Health and Nutrition Examination Survey. A total of 4,481 participants over 19 years of age without diabetic medications and conditions to influence the interpretation of HbA1c levels, such as anemia, renal insufficiency, liver cirrhosis, and cancers, were analyzed. A point-wise area under the receiver operating characteristic curve was used to estimate the optimal HbA1c cutoff value. A HbA1c threshold of 6.35% was optimal for predicting diabetes with a sensitivity of 86.9% and a specificity of 99.1%. Furthermore, the threshold of HbA1c was 5.65% for prediabetes, with a sensitivity of 69.3% and a specificity of 71%. Further prospective studies are needed to evaluate the HbA1c cutoff point for diagnosing prediabetes and diabetes in the Korean population.
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The Korea National Health and Nutrition Examination Survey (KNHANES) III (2005) reported that 22.9% of individuals with diabetes have a glycated hemoglobin (HbA1c) <6.5% and that 43.5% have an HbA1c <7%. We investigated the levels of glycemic control and the factors associated with glycemic control using data from the KNHANES V (2010 to 2012).
Subjects with diabetes diagnosed by a physician or those taking antidiabetic medications were classified as individuals with known diabetes. Of 1,498 subjects aged ≥30 years with diabetes, we excluded 157 individuals who were missing HbA1c data. A total of 1,341 subjects were included in the final analysis.
The prevalence of known diabetes was 7.7% (
The level of adequate glycemic control was similar to but slightly improved compared with previous levels. The glycemic control of long-standing diabetes patients is more difficult even though they receive insulin treatment.
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Diabetic nephropathy is a leading cause of end stage renal disease and is associated with an increased risk of cardiovascular mortality. It manifests as albuminuria or impaired glomerular filtration rate (GFR), and the prevalence of diabetic nephropathy varies with ethnicity. The prevalence of diabetic nephropathy and its determinants in Korean adults have not previously been studied at the national level. This cross-sectional study was undertaken to ascertain the prevalence and determinants of albuminuria and chronic kidney disease (CKD) in Korean patients with diabetes.
The Korea National Health and Nutrition Examination Survey (KNHANES) V, conducted in 2011, was used to define albuminuria (
Among subjects with diabetes, 26.7% had albuminuria, and 8.6% had CKD. Diabetes was associated with an approximate 2.5-fold increased risk of albuminuria, with virtually no difference between new-onset and previously diagnosed diabetes. Only systolic blood pressure was significantly associated with albuminuria, and old age, high serum triglyceride levels, and previous cardiovascular disease (CVD) were related with CKD in subjects with diabetes.
Korean subjects with diabetes had a higher prevalence of albuminuria and CKD than those without diabetes. Blood pressure was associated with albuminuria, and age, triglyceride level, and previous CVD were independent determinants of CKD in subjects with diabetes.
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We investigated the prevalence, awareness, treatment, and control rate of hypertension in Korean adults with diabetes using nationally representative data.
Using data of 5,105 adults from the fifth Korea National Health and Nutrition Examination Survey in 2011 (4,389 nondiabetes mellitus [non-DM]), 242 newly diagnosed with DM (new-DM), and 474 previously diagnosed with DM (known-DM), we analyzed the prevalence of hypertension (mean systolic blood pressure ≥140 mm Hg, diastolic blood pressure ≥90 mm Hg, or use of antihypertensive medication) and control rate of hypertension (blood pressure [BP] <130/80 mm Hg).
The prevalence of hypertension in diabetic adults was 54.6% (44.4% in new-DM and 62.6% in known-DM,
Higher prevalence and low control rate of hypertension in adults with diabetes suggest that stringent efforts are needed to control BP in patients with diabetes, particularly in newly diagnosed diabetic patients.
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Obesity is a risk factor for diabetes and several cardiovascular diseases. This study was to investigate the trends in the prevalence, awareness, and management status of obesity among the Korean population for recent 13 years.
The prevalence, subjective awareness, and management of obesity were investigated in adults aged ≥19 years by using the data from the Korea National Health and Nutrition Examination Surveys (KNHANES) 1998 to 2011.
The number of participants was 8,117, 5,826, 5,500, 3,025, 6,756, 7,506, 6,255, and 6,155 in the KNHANES in years 1998, 2001, 2005, 2007, 2008, 2009, 2010, and 2011, respectively. The prevalence of obesity was 26.9%, 29.2%, 32.9%, 32.5%, 32.0%, 32.6%, 32.0%, and 32.0% in 1998, 2001, 2005, 2007, 2008, 2009, 2010, and 2011, respectively, while the overall prevalence of obesity and abdominal obesity increased by 1.19-fold and 1.24-fold respectively in 2011 compared against 2001. In general, a gradual increase in the prevalence of severe obesity has been observed as years go by. Furthermore, trends of improvements in obesity awareness and management rates were visible over the period of surveys.
Although the management status of obesity has improved during the recent years, more effective strategy to control obesity is needed.
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Dyslipidemia is a major risk factor of cardiovascular disease. The aim of this study was to investigate the changing trends in the prevalence and management status of dyslipidemia among Korean adults.
The prevalence of dyslipidemia and the rates of awareness, treatment, and control of dyslipidemia were investigated in adults aged ≥20 years from the Korea National Health and Nutrition Surveys (KNHANES) 1998 to 2010. The updated National Cholesterol Education Program criteria was used, which define dyslipidemia as having one or more of the following lipid abnormalities: hypercholesterolemia (total cholesterol ≥240 mg/dL or diagnosis of dyslipidemia or use of lipid-lowering drugs), hypertriglyceridemia (≥150 mg/dL), hyper-low density lipoprotein (LDL) cholesterolemia (≥160 mg/dL or diagnosis of dyslipidemia or use of lipid-lowering drugs), and hypo-high density lipoprotein (HDL)-cholesterolemia (<40 mg/dL in men and <50 mg/dL in women).
The number of participants was 6,921, 4,894, 5,312, 2,733, 6,295, 6,900, and 5,738 in KNHANES 1998, 2001, 2005, 2007, 2008, 2009, and 2010, respectively. Age-standardized prevalence rates of dyslipidemia were 54.0%, 65.8%, 66.5%, 60.6%, 58.7%, 58.9%, and 59.0% in 1998, 2001, 2005, 2007, 2008, 2009, and 2010, respectively. Hypertriglyceridemia and hypo-HDL-cholesterolemia were the two most frequent lipid abnormalities. The overall prevalence of hypercholesterolemia and hyper-LDL-cholesterolemia increased by 1.36- and 1.35-fold in 2010 compared with 2007, respectively. Awareness, treatment, and control rates of dyslipidemia improved over the period of surveys in both sexes. In 2010, about 30% of dyslipidemic patients who received lipid-lowering treatment reached target levels.
Although the management status of dyslipidemia has improved during recent years, effective strategy is required for achieving better prevention, treatment, and control of dyslipidemia.
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Due to the inconvenience of performing oral glucose tolerance tests and day to day variability in glucose level, glycated hemoglobin (HbA1c) has been recommended by the American Diabetes Association as a method to diagnose diabetes. In addition, the Korean Diabetes Association has also recommended the use of HbA1c as a diagnostic test for diabetes. In this study, we evaluated the prevalence of diabetes according to fasting plasma glucose (FPG) level only or the combination of FPG and HbA1c tests.
Data from the 2011 Korea National Health and Nutrition Examination Survey (KNHANES) were analyzed. Among 5,811 subjects aged 30 years or older, 5,020 were selected after excluding the data of fasting time <8 hours, missing values from fasting glucose or HbA1c level, previous diagnosis of diabetes made by physicians, or current use of antidiabetic medications. Diabetes was defined as FPG ≥126 mg/dL, previous diagnosis of diabetes made by a medical doctor, current use of antidiabetic medications, and/or HbA1c ≥6.5%. Prediabetes was defined as FPG of 100 to 125 mg/dL and/or HbA1c of 5.7% to 6.4%.
When we used FPG only, the prevalence of diabetes and prediabetes were 10.5% (men, 12.6%; women, 8.5%) and 19.3% (men, 23.8%; women, 14.9%), respectively. When HbA1c was included as a diagnostic test, the prevalence of diabetes and prediabetes increased to 12.4% (men, 14.5%; women, 10.4%) and 38.3% (men, 41%; women, 35.7%), respectively. Participants with HbA1c ≥6.5% and fasting glucose level <126 mg/dL were older and had lower estimated glomerular filtration rate.
We concluded that using fasting glucose level only may result in an underestimation of diabetes and prediabetes. HbA1c is an acceptable complementary diagnostic test for diabetes in Korean patients. However, national standardization is needed to order to use HbA1c as a diagnostic method of diabetes and prediabetes.
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Little is known about the relative contribution of long-term glycemic variability to the risk of macrovascular complications in type 2 diabetes. This study was conducted to evaluate the effect of A1C variability on the progression of carotid artery intima-media thickness (IMT) in type 2 diabetic patients.
Among type 2 diabetic patients who visited Hallym University Sacred Heart Hospital from March 2007 to September 2009, 120 patients who had carotid artery IMT measured annually and A1C checked every three months for at least one year were analyzed. Individual A1C variability was defined as the standard deviation (SD) of five A1C levels taken every three months for approximately one year. Change in IMT was defined as an increase in IMT on follow-up measurement. The association between the SD of A1C and changes in IMT was evaluated.
With greater A1C variability, there was a greater increase in the mean IMT (
Higher A1C variability is associated with IMT progression in type 2 diabetic patients; however, it is not an independent predictor of IMT progression. Overall glycemic control is the most important factor in the progression of IMT.
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