Type 2 diabetes mellitus (T2DM) is increasing in prevalence worldwide. The complications associated with T2DM result in increased mortality and financial cost for those affected. T2DM has long been known to be associated with insulin resistance in peripheral tissues and a relative degree of insulin deficiency. However, the concept that insulin secretion and insulin sensitivity are not linked through a hyperbolic relationship in T2DM has continuously been demonstrated in many clinical trials. Thus, in order to prevent and treat T2DM, it is necessary to identify the substance(s) that will improve the function and survival of the pancreatic β-cells in both normal and pathologic conditions, so that production and secretion of insulin can be enhanced. Incretin hormones, such as glucagon-like peptide (GLP)-1 and glucose-dependent insulinotropic polypeptide (GIP), have been shown to lower the postprandial and fasting glucose and the glycated hemoglobin levels, suppress the elevated glucagon level, and stimulate glucose-dependent insulin synthesis and secretion. In this report, we will review the biological actions and mechanisms associated with the actions of incretin hormones, GLP-1 and GIP, on β-cell health and compare the differences between GLP-1 and GIP.
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To determine the factors responsible for the dramatic increase in the prevalence of diabetes in Korea. A computerized literature survey was conducted to evaluate the risk factors for Type 2 diabetes mellitus (T2DM) in Korea, including genome-wide association studies. National Statistics gross national income data was integrated with the reported prevalence of diabetes to evaluate the relationship between diabetes and the economic growth. The strength of the association was evaluated using measures of effect size, such as odds ratio and relative risks. The putative risk factors identified in Korean studies are very similar to the risk factors identified from the other countries, including genetic background. Genome-wide association studies reported relative risks of 1.5 or less, indicating that no single gene is associated with the risk of T2DM. The scientific evidence suggests that the dramatic increase in the incidence and prevalence of T2DM in Korea is related to the economic development of Korea, which has a direct influence on health policy, as well as an individual's health behaviors. We expect to observe the current diabetes incidence rates until the key risk factors are present for long enough in our society, at which point we would expect to start observing a more gradual increase in both the incidence and prevalence of T2DM in Korea.
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A conference was convened by the Korean Diabetes Association and the Korean Endocrine Society on September 7, 2009 to discuss and organize the results of research on intensive glucose control for the prevention of cardiovascular disease in patients with type 2 diabetes. Professor Kyung Soo Park led the conference, and Professors Kwang Won Kim and Ho Young Son acted as chairmen. Professors Doo Man Kim, Tae Sun Park, and Bong Soo Cha reported on intensive glucose control and diabetic complications, including the UK Prospective Diabetes Study (UKPDS), Diabetes Control and Complication Trial (DCCT) research results, the recently published Action to Control Cardiovascular Risk in Diabetes (ACCORD), Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE), and Veterans Affairs Diabetes Trial (VADT) research, as well as meta-analyses. Professor Jeong-Taek Woo reported on the manuscript written by the committee for the Korean Diabetes Association which dealt with the treatment of diabetes mellitus. Professors Kyung Soo Ko, Joong Yeol Park, Hyun Shik Son, Moon-Kyu Lee, Dong-Won Byun, and Yoon-Sok Chung participated in the discussion and collected information for the manuscript from all of the participants. The aim of the debate was to determine how to establish target goals for intensive glucose control and how to individualize those goals. The participants concluded that there was no need to modify the recommendation of maintaining an HbA1c under 6.5%, the current blood glucose treatment goal that is recommended by the Korean Diabetes Association. In addition, individual target goals for glucose control were recommended depending on the situation of each patient. We report on the consensus statement from the meeting.
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Aerobic exercise can effectively reduce visceral fat. However, few studies have examined the effect of daily physical activity on obesity and cardiopulmonary function in the subjects with diabetes. We examined the effect of moderate intensity of walking in obese diabetes patients by monitoring of daily activity and measuring the change in abdominal fat area, muscle are and maximal muscle strength.
We randomly assigned 27 obese women with type 2 diabetes to an aerobic exercise group (AG, n = 13) and control group (CG, n = 14). The AG performed moderate intensity walking for 60 minutes per exercise, 5 times per week, and for 12 weeks. The activity energy expenditure was monitored by a multi-record accelerometer. The CG maintained routine daily activities. At the time of the initiation of the study and after 12 weeks of exercise, the aerobic exercise capacity was assessed using oxygen consumption rate at anaerobic threshold (VO2-AT). The abdominal fat area and the quadriceps muscle area were measured by computed tomography, and the maximum muscle strength of the upper and lower limbs was measured by a chest press and a leg press, respectively.
The mean age of the study subjects was 56.6 ± 8.0 years, the mean duration of diabetes was 6.3 ± 6.0 years, and the body weight index (BMI) was 27.3 ± 2.7 kg/m2. The BMI of the AG was significantly decreased (
Daily moderate intensity aerobic exercise is effective at reducing abdominal fat mass, while high intensity exercise improves cardiopulmonary function.
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Our aim was to assess the validity of a semi-quantitative food frequency questionnaire (FFQ) by comparison with the 3-day diet record (DR) in patients with type 2 diabetes.
Eighty five type 2 diabetic patients (aged 33 to 70 years) from the Korean National Diabetes Program (KNDP) completed 3-day DR and FFQ. The FFQ was designed to reflect the eating pattern of Korean type 2 diabetic patients, and was based on the 2003 Korean National Health and Nutrition Examination Survey. The FFQ consists of 85 food items and 12 food groups. The validity of FFQ was assessed by comparison with the 3-day DR.
The mean age was 49 ± 10 years. Clinical characteristic including body weight, diabetic duration, and HbA1c were not different from the total cohort subjects (
The FFQ is a reasonable instrument for assessing the intake of most macronutrients in Korean type 2 diabetes, although careful consideration is required for the food groups and nutrients for which the FFQ had low validity.
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Hypertension and age are recognized as important risk factors for left ventricular (LV) diastolic dysfunction. Some studies have shown that diabetes itself may also be an independent risk factor for LV diastolic dysfunction, although this is controversial. The aim of this study was to determine the factors associated with LV diastolic dysfunction in patients with type 2 diabetes in the absence of hypertension or ischemic heart disease (IHD).
Participants in this study consisted of 65 type 2 diabetes patients (M : F = 45 : 20; mean age 51 [26 to 76] years; mean body mass index [BMI] 25.0 ± 2.5 kg/m2) without hypertension, heart disease, or renal disease. Individuals with ischemic electrocardiographic changes were excluded. LV diastolic function was evaluated by Doppler echocardiographic studies.
Fifteen patients (23.1%) showed LV diastolic dysfunction on Doppler echocardiographic studies. Patients with LV diastolic dysfunction were older than those without diastolic dysfunction (60.0 ± 2.5 vs. 50.5 ± 1.9 years;
These results suggest that diabetes duration may be a risk factor for LV diastolic dysfunction in type 2 diabetic patients without hypertension or IHD.
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Blood glucose level continuously fluctuates within a certain range in the human body. In diabetes patients, the extent of such fluctuation is large, despite the strict control of blood glucose. Blood glucose fluctuation has been shown to mediate more adverse effects on vascular endothelial cells and diabetes complications than chronic hyperglycemia, which has been explained as due to oxidative stress. As few previous studies have reported the effects of chronic and intermittent hyperglycemia on the apoptosis and function of pancreatic beta cells, this study reported herein was performed to investigate such effects on these cells.
For chronic hyperglycemia, INS-1 cells were cultured for 5 days with changes of RPMI 1640 medium containing 33 mM glucose every 12 hours. For intermittent hyperglycemia, the medium containing 11 mM glucose was exchanged with the medium containing 33 mM glucose every 12 hours. Apoptosis was assessed by TUNEL assay Hoechst staining and cleaved caspase 3. Insulin secretory capacity was assessed, and the expression of Mn-SOD and Bcl-2 was measured by Western blotting.
In comparison to the control group, INS-1 cells exposed to chronic hyperglycemia and intermittent hyperglycemia showed an increase in apoptosis. The apoptosis of INS-1 cells exposed to intermittent hyperglycemia increased significantly more than the apoptosis of INS-1 cells exposed to chronic hyperglycemia. In comparison to the control group, the insulin secretory capacity in the two hyperglycemic states was decreased, and more with intermittent hyperglycemia than with chronic hyperglycemia. The expression of Mn-SOD and Bcl-2 increased more with chronic hyperglycemia than with intermittent hyperglycemia.
Intermittent hyperglycemia induced a higher degree of apoptosis and decreased the insulin secretory capacity more in pancreatic beta cells than chronic hyperglycemia. This activity may be mediated by the anti-oxidative enzyme Mn-SOD and the anti-apoptotic signal Bcl-2.
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This study was conducted to evaluate the factors affecting medication adherence in geriatric diabetic patients treated at private clinics and tertiary hospitals. We compared the factors affecting medication adherence between these two patient groups.
We included 108 diabetic patients older than 65 years treated at one tertiary hospital and 157 patients older than 65 years treated at two private clinics. We conducted an interview survey based on the Health Belief Model, and used a questionnaire that included the self-efficacy variable. For the medication adherence, Morisky's self-report was used.
The medication adherence based on Morisky's self-report was significantly higher in tertiary hospital patients (61.1%) compared to private clinic patients (43.2%) (
Different strategies should be used to increase medication adherence in geriatric diabetic patients, depending on institutions whether they are treated.
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