Impaired fasting glucose levels in overweight or obese subjects for screening of type 2 diabetes in Korea

Background/Aims@#We examined the concordance rate among fasting plasma glucose (FPG), 2-hour post-challenge glucose (2hr PG), and hemoglobin A1c (HbA1c) in the diagnosis of diabetes in a population with a high-risk for type 2 diabetes mellitus (T2DM) in Korea. @*Methods@#Among the participants from the Korean Diabetes Prevention Study, individuals with FPG ≥ 100 mg/dL, body mass index (BMI) ≥ 23.0 kg/m2, and no previous history of T2DM were consecutively enrolled after a 75 g glucose tolerance test. We analyzed the differences in the clinical characteristics in subjects with stage 1 (FPG, 100 to 109 mg/dL) and stage 2 (FPG, 110 to 125 mg/dL) impaired fasting glucose (IFG). @*Results@#Of 1,637 participants, 27.2% had T2DM and 59.3% had IFG and/or impaired glucose tolerance (IGT). The mean age was 55.0 ± 8.1 years and the mean BMI was 26.3 ± 2.7 kg/m2. Based on FPG criteria, 515 (31.4%) and 352 (21.5%) subjects were classified as having stage 1 and stage 2 IFG, respectively. The 19.0% of stage 1 and 43.5% of stage 2 subjects showed 2hr PG levels in the diabetic range. Even for those in the normal FPG range, 63 (9.5%) participants showed a 2hr PG level of ≥ 200 mg/dL. Of 446 subjects with newly-diagnosed diabetes, 340 (76.2%) showed FPG levels < 126 mg/dL. @*Conclusions@#The oral glucose tolerance test should be actively considered for Korean adults who are overweight or obese with the IFG range (FPG, 100 to 125 mg/ dL) to allow for early detection of diabetes and prompt intervention.

Effect of Dipeptidyl Peptidase-4 Inhibitors on the Risk of Bone Fractures in a Korean Population

BACKGROUND: There have been equivocal results in studies of the effects of dipeptidyl peptidase-4 inhibitors (DPP-4i) on fractures. In this study, we analyzed the effect of DPP-4i on bone fracture risk in a Korean population. METHODS: We extracted subjects (n = 11,164) aged 50 years or older from the National Health Insurance Service–National Sample Cohort 2.0 from 2009 to 2014. Our control group included subjects without diabetes (n = 5,582), and our treatment groups with diabetes included DPP-4i users (n = 1,410) and DPP-4i non-users (n = 4,172). The primary endpoint was the incidence of a composite outcome consisting of osteoporosis diagnosis, osteoporotic fractures, vertebral fractures, non-vertebral fractures, and femoral fractures. The secondary endpoint was the incidence of each individual component of the composite outcome. Survival analysis was performed with adjustment for age, gender, diabetes complications severity index, Charlson comorbidity index, hypertension medication, and dyslipidemia treatment. RESULTS: The incidence of the composite outcome per 1,000 person-years was 0.089 in DPP-4i users, 0.099 in DPP-4i non-users, and 0.095 in controls. There was no significant difference in fracture risk between DPP-4i users and DPP-4i non-users or controls after the adjustments (P > 0.05). The incidences of osteoporosis diagnosis, osteoporotic fractures, vertebral fractures, non-vertebral fractures, and femoral fractures were not significantly different between DPP-4i users and non-users. The results of subgroup analyses by gender and age were consistent. CONCLUSION: DPP-4i had no significant effect on the risk of fractures in a Korean population.

Hospital-Based Korean Diabetes Prevention Study: A Prospective, Multi-Center, Randomized, Open-Label Controlled Study

BACKGROUND: The prevalence of diabetes mellitus (DM) continues to increase, and the disease burden is the highest of any medical condition in Korea. However, large-scale clinical studies have not yet conducted to establish the basis for diabetes prevention in Korea. METHODS: The hospital-based Korean Diabetes Prevention Study (H-KDPS) is a prospective, multi-center, randomized, open-label controlled study conducted at university hospitals for the purpose of gathering data to help in efforts to prevent type 2 DM. Ten university hospitals are participating, and 744 subjects will be recruited. The subjects are randomly assigned to the standard care group, lifestyle modification group, or metformin group, and their clinical course will be observed for 36 months. RESULTS: All intervention methodologies were developed, validated, and approved by Korean Diabetes Association (KDA) multi-disciplinary team members. The standard control group will engage in individual education based on the current KDA guidelines, and the lifestyle modification group will participate in a professionally guided healthcare intervention aiming for ≥5% weight loss. The metformin group will begin dosing at 250 mg/day, increasing to a maximum of 1,000 mg/day. The primary endpoint of this study is the cumulative incidence of DM during the 3 years after randomization. CONCLUSION: The H-KDPS study is the first large-scale clinical study to establish evidence-based interventions for the prevention of type 2 DM in Koreans. The evidence gathered by this study will be useful for enhancing the health of Koreans and improving the stability of the Korean healthcare system (Trial registration: CRIS KCT0002260, NCT02981121).

Presence of Carotid Plaque Is Associated with Rapid Renal Function Decline in Patients with Type 2 Diabetes Mellitus and Normal Renal Function

BACKGROUND: Recent evidences indicate that early rapid renal function decline is closely associated with the development and progression of diabetic kidney disease. We have investigated the association between carotid atherosclerosis and rapid renal function decline in patients with type 2 diabetes mellitus and preserved renal function.METHODS: In a prospective, multicenter cohort, a total of 967 patients with type 2 diabetes mellitus and preserved renal function were followed for 6 years with serial estimated glomerular filtration rate (eGFR) measurements. Common carotid intima-media thickness (CIMT) and presence of carotid plaque were assessed at baseline. Rapid renal function decline was defined as an eGFR decline >3.3% per year.RESULTS: Over a median follow-up of 6 years, 158 participants (16.3%) developed rapid renal function decline. While there was no difference in CIMT, the presence of carotid plaque in rapid decliners was significantly higher than in non-decliners (23.2% vs. 12.2%, P<0.001). In multivariable logistic regression analysis, presence of carotid plaque was an independent predictor of rapid renal function decline (odds ratio, 2.33; 95% confidence interval, 1.48 to 3.68; P<0.0001) after adjustment for established risk factors. The model including the carotid plaque had better performance for discrimination of rapid renal function decline than the model without carotid plaque (area under the receiver operating characteristic curve 0.772 vs. 0.744, P=0.016).CONCLUSION: Close monitoring of renal function and early intensive management may be beneficial in patients with type 2 diabetes mellitus and carotid plaques.

Analysis of diabetes quality assessment findings and future directions for the appropriate management of diabetes in Korea

BACKGROUND/AIMS: Due to recent increases in the disease burden of diabetes mellitus, the Health Insurance Review and Assessment Service (HIRA) of Korea implemented a quality assessment of the treatment of diabetes to improve patient care. The present study was conducted to identify any changes after the implementation of the diabetes quality assessment (DQA). METHODS: The present study evaluated eight quality assessment indicators that were proposed by the HIRA in all patients with diabetes who visited a university hospital in Korea between 2009 and 2014. The indicators were statistically compared according to the characteristics of the subjects. RESULTS: There were several significant differences in the indicators among the subjects according to their demographic characteristics. Female patients had a higher continuity of treatment (COT) than that of male patients, and the insulin-treated group had a higher COT than that of the non-treated group, as well as a higher rate of undergoing the diabetes complication tests (DCTs). Patients between 40 and 80 years of age had the highest COT, while patients under 40 years of age had the lowest COT but the highest rate of taking the DCTs. Patients receiving treatment from an endocrinologist exhibited higher numbers of DCTs performed but displayed lower proportions for the prescription indicators. CONCLUSIONS: The present analysis of the DQA findings revealed that endocrinologists combine prevention and management of diabetes complications with measures for glycemic control. Thus, the effective management of diabetes likely entails systematic joint treatment regimens that involve an endocrinologist.

A Nutrition Intervention Focused on Weight Management Through Lifestyle Improvements in Prediabetic Subjects

We reported the cases in order to evaluate the effects of individualized nutrition interventions for enhancing self-management abilities of prediabetic subjects. We conducted four nutrition interventions for weight control in two subjects with high-risk of type 2 diabetes. The first subject was a 53-year-old housewife, and the second subject was a 46-year-old male office worker. The subjects visited the medical center 4 times during the study period, and the lifestyle interventions were advised by a clinical team comprised physicians, clinical dietitians, and nurses. In particular, nutrition intervention to achieve weight loss focused on enhancing motivation and problem-solving skills to improve self-management ability. As a result, both subjects achieved weight loss by the time of their last visits. These two case studies, which differed in terms of sex, occupation, and dietary habits showed the importance of individualized nutrition intervention and forming an intimate relationship based on trust centered on prediabetic subjects. In conclusion, systematic collaboration within the clinical team is necessary, and social infrastructure should be prepared to fully realize the benefits of a systematic intervention program.

Impact of Socioeconomic Status on Health Behaviors, Metabolic Control, and Chronic Complications in Type 2 Diabetes Mellitus

BACKGROUND: The aim of the study was to assess the impact of socioeconomic status (SES) on health behaviors, metabolic control, and chronic complications in people with type 2 diabetes mellitus (T2DM) from South Korea, a country with universal health insurance coverage and that has experienced rapid economic and social transition. METHODS: A total of 3,294 Korean men and women with T2DM aged 30 to 65 years, participating in the Korean National Diabetes Program (KNDP) cohort who reported their SES and had baseline clinical evaluation were included in the current cross-sectional analysis. SES included the level of education and monthly household income. RESULTS: Lower education level and lower income level were closely related, and both were associated with older age in men and women. Women and men with lower income and education level had higher carbohydrate and lower fat intake. After adjustment for possible confounding factors, higher education in men significantly lowered the odds of having uncontrolled hyperglycemia (glycosylated hemoglobin ≥7.5%) (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.43 to 0.91 for highest education; P(trend)=0.048), while higher household income in men significantly lowered the odds of having diabetic retinopathy (OR, 0.59; 95% CI, 0.37 to 0.95 for highest income level; P(trend)=0.048). In women, lower income was associated with a higher stress level. CONCLUSION: Men with lower SES had higher odds of having diabetic retinopathy and uncontrolled hyperglycemia, showing the need to improve care targeted to this population.

Cardio-Ankle Vascular Index as a Surrogate Marker of Early Atherosclerotic Cardiovascular Disease in Koreans with Type 2 Diabetes Mellitus

BACKGROUND: Carotid artery intima medial thickness (IMT), brachial-ankle pulse wave velocity (baPWV), and ankle-brachial index (ABI) are commonly used surrogate markers of subclinical atherosclerosis in patients with type 2 diabetes mellitus (T2DM). The cardio-ankle vascular index (CAVI) is a complement to the baPWV, which is affected by blood pressure. However, it is unclear which marker is the most sensitive predictor of atherosclerotic cardiovascular disease (ASCVD). METHODS: This was a retrospective non-interventional study that enrolled 219 patients with T2DM. The correlations among IMT, ABI, and CAVI as well as the relationship of these tests to the 10-year ASCVD risk were also analyzed. RESULTS: Among the 219 patients, 39 (17.8%) had ASCVD. In the non-ASCVD group, CAVI correlated significantly with IMT after adjusting for confounding variables, but ABI was not associated with CAVI or IMT. The analyses after dividing the non-ASCVD group into three subgroups according to the CAVI score ( < 8, ≥8 and < 9, and ≥9) demonstrated the significant increase in the mean IMT, 10-year ASCVD risk and number of metabolic syndrome risk factors, and decrease in the mean ABI in the high-CAVI group. A high CAVI was an independent risk factor in the non-ASCVD group for both a high 10-year ASCVD risk (≥7.5%; odds ratio [OR], 2.42; P < 0.001) and atherosclerosis (mean IMT ≥1 mm; OR, 1.53; P=0.007). CONCLUSION: In Korean patients with T2DM without ASCVD, CAVI was the most sensitive of several surrogate markers for the detection of subclinical atherosclerosis.

Air Pollution Has a Significant Negative Impact on Intentional Efforts to Lose Weight: A Global Scale Analysis

BACKGROUND: Air pollution causes many diseases and deaths. It is important to see how air pollution affects obesity, which is common worldwide. Therefore, we analyzed data from a smartphone application for intentional weight loss, and then we validated them. METHODS: Our analysis was structured in two parts. We analyzed data from a cohort registered to a smartphone application in 10 large cities of the world and matched it with the annual pollution values. We validated these results using daily pollution data in United States and matching them with user information. Body mass index (BMI) variation between final and initial login time was considered as outcome in the first part, and daily BMI in the validation. We analyzed: daily calories intake, daily weight, daily physical activity, geographical coordinates, seasons, age, gender. Weather Underground application programming interface provided daily climatic values. Annual and daily values of particulate matter PM10 and PM2.5 were extracted. In the first part of the analysis, we used 2,608 users and then 995 users located in United States. RESULTS: Air pollution was highest in Seoul and lowest in Detroit. Users decreased BMI by 2.14 kg/m2 in average (95% confidence interval, −2.26 to −2.04). From a multilevel model, PM10 (β=0.04, P=0.002) and PM2.5 (β=0.08, P < 0.001) had a significant negative effect on weight loss when collected per year. The results were confirmed with the validation (βAQI*time=1.5×10–5; P < 0.001) by mixed effects model. CONCLUSION: This is the first study that shows how air pollution affects intentional weight loss applied on wider area of the world.

Artificial Pancreas: A Concise Review / 임상당뇨병

Artificial pancreas is a technique developed to automatically control blood glucose in people with diabetes by providing an endocrine function instead of a healthy pancreas. The technique was developed for the replacement of insulin secretion deficiencies among various exocrine and endocrine functions of the pancreas and is mainly used for people with type 1 diabetes or those who need intensive insulin treatment. This review briefly summarizes the working principles, components, recent clinical research, and future perspectives of artificial pancreas.

Effects of Lobeglitazone, a Novel Thiazolidinedione, on Bone Mineral Density in Patients with Type 2 Diabetes Mellitus over 52 Weeks

BACKGROUND: The aim of this multicenter, randomized, double-blind study was to examine the effect of lobeglitazone, a novel thiazolidinedione, on the changes in bone mineral density (BMD) in patients with type 2 diabetes mellitus. METHODS: A 24-week, double-blinded phase was followed by a 28-week, open-label phase, in which the placebo group also started to receive lobeglitazone. A total of 170 patients aged 34 to 76 years were randomly assigned in a 2:1 ratio to receive lobeglitazone 0.5 mg or a matching placebo orally, once daily. BMD was assessed using dual-energy X-ray absorptiometry at week 24 and at the end of the study (week 52). RESULTS: During the double-blinded phase, the femur neck BMD showed decreasing patterns in both groups, without statistical significance (−0.85%±0.36% and −0.78%±0.46% in the lobeglitazone and placebo groups, respectively). The treatment difference between the groups was 0.07%, which was also not statistically significant. Further, minimal, nonsignificant decreases were observed in both groups in the total hip BMD compared to values at baseline, and these differences also did not significantly differ between the groups. During the open-label phase, the BMD was further decreased, but not significantly, by −0.32% at the femur neck and by −0.60% at the total hip in the lobeglitazone group, and these changes did not significantly differ compared with the original placebo group switched to lobeglitazone. CONCLUSION: Our results indicate that treatment with lobeglitazone 0.5 mg over 52 weeks showed no detrimental effect on the BMD compared to the placebo.

Features of Long-Standing Korean Type 2 Diabetes Mellitus Patients with Diabetic Retinopathy: A Study Based on Standardized Clinical Data

BACKGROUND: This is part of a prospective study carried out as a national project to secure standardized public resources for type 2 diabetes mellitus (T2DM) patients in Korea. We compared various characteristics of long-standing T2DM patients with diabetic retinopathy (DR) and macular edema (ME). METHODS: From September 2014 to July 2015, T2DM patients with disease duration of at least 15 years were recruited at a single university hospital. Clinical data and samples were collected according to the common data elements and standards of procedure developed by the Korean Diabetes Association Research Council. Each participant was assessed by ophthalmologists for DR and ME. RESULTS: Among 220 registered patients, 183 completed the ophthalmologic assessment. DR was associated with longer disease duration (odds ratio [OR], 1.071; 95% confidence interval [CI], 1.001 to 1.147 for non-proliferative diabetic retinopathy [NPDR]) (OR, 1.142; 95% CI, 1.051 to 1.242 for proliferative diabetic retinopathy [PDR]) and the use of long-acting insulin (OR, 4.559; 95% CI, 1.672 to 12.427 for NPDR) (OR, 4.783; 95% CI, 1.581 to 14.474 for PDR), but a lower prevalence of a family history of cancer (OR, 0.310; 95% CI, 0.119 to 0.809 for NPDR) (OR, 0.206; 95% CI, 0.063 to 0.673 for PDR). ME was associated with higher glycosylated hemoglobin levels (OR, 1.380; 95% CI, 1.032 to 1.845) and the use of rapid-acting insulin (OR, 5.211; 95% CI, 1.445 to 18.794). CONCLUSION: Various clinical features were associated with DR and ME. Additional epidemiological and biorepository-based studies using this cohort are being conducted to deepen our understanding of diabetic complications in Korea.

Response: Features of Long-Standing Korean Type 2 Diabetes Mellitus Patients with Diabetic Retinopathy: A Study Based on Standardized Clinical Data (Diabetes Metab J 2017;41:393-404)

No abstract available.

Effects of Rebamipide on Gastrointestinal Symptoms in Patients with Type 2 Diabetes Mellitus

BACKGROUND: Gastrointestinal (GI) symptoms are common in patients with type 2 diabetes mellitus (T2DM). Rebamipide is an effective gastric cytoprotective agent, but there are few data on its usefulness in T2DM. The aim of this study is to evaluate the improvement of GI symptoms after rebamipide treatment in patients with T2DM. METHODS: Patients with T2DM and atypical GI symptoms were enrolled. They took rebamipide (100 mg thrice daily) for 12 weeks and filled out the diabetes bowel symptom questionnaire (DBSQ) before and after rebamipide treatment. The DBSQ consisted of 10 questions assessing the severity of GI symptoms by a 1 to 6 scoring system. Changes in the DBSQ scores before and after rebamipide treatment were analyzed to evaluate any improvements of GI symptoms. RESULTS: A total of 107 patients were enrolled, and 84 patients completed the study. The mean age was 65.0±7.8, 26 patients were male (24.8%), the mean duration of T2DM was 14.71±9.12 years, and the mean glycosylated hemoglobin level was 6.97%±0.82%. The total DBSQ score was reduced significantly from 24.9±8.0 to 20.4±7.3 before and after rebamipide treatment (P<0.001). The DBSQ scores associated with reflux symptoms, indigestion, nausea or vomiting, abdominal bloating or distension, peptic ulcer, abdominal pain, and constipation were improved after rebamipide treatment (P<0.05). However, there were no significant changes in symptoms associated with irritable bowel syndrome, diarrhea, and anal incontinence. No severe adverse events were reported throughout the study. CONCLUSION: Rebamipide treatment for 12 weeks improved atypical GI symptoms in patients with T2DM.

Clinical Outcome Research through Patient Registries / 임상당뇨병

As our population ages, so grows the amount of medical expenditures. In the future, elderly people will be better organized, more assertive and have higher expectations of their quality of life. More advanced health technologies have been developed with potential harm as well as beneficial effectiveness. We should provide the patients with health technologies with high scientific evidences. Randomized control trials (RCTs) provide the highest level of scientific evidence, but cannot always be performed because of ethical, practical or financial limitations, and do not always reflect what occurs in real clinical practice. However, patient registries can be used to evaluate patient outcomes through prospective evaluation of a structured collection of clinical information. Therefore, patient registries can complement RCTs.

A Case of Type 2 Diabetes Mellitus with Severe Insulin Resistance and Dumping Syndrome after Bariatric Surgery

Patients with diabetes undergo bariatric surgery to improve sugar metabolism and to achieve weight loss. However, possible complications after bariatric surgery must be carefully considered. We report a case of uncontrolled blood sugar after bariatric surgery despite weight loss in a severely obese patient with diabetes. The patient underwent bariatric surgery in 2009 in order to lose weight and improve glycemic control. Six months after the surgery, the patient experienced dumping syndrome. The patient did actually lose weight; however, as the visceral fat/subcutaneous fat+visceral fat ratio increased, insulin resistance was not improved, and glycemic control was aggravated. The patient received proper medication for dumping syndrome including nutritional support and exercise education. Due to these efforts, the patient has maintained her weight loss, and her blood sugar level was controlled within the target range.

A Smartphone Application Signif icantly Improved Diabetes Self-Care Activities with High User Satisfaction

BACKGROUND: We developed for the first time a smartphone application designed for diabetes self-management in Korea and registered a patent for the relevant algorithm. We also investigated the user satisfaction with the application and the change in diabetes related self-care activities after using the application. METHODS: We conducted a questionnaire survey on volunteers with diabetes who were using the application. Ninety subjects responded to the questionnaire between June 2012 and March 2013. A modified version of the Summary of Diabetes Self-Care Activities (SDSCA) was used in this study. RESULTS: The survey results exhibited a mean subject age of 44.0 years old, and males accounted for 78.9% of the subjects. Fifty percent of the subjects had diabetes for less than 3 years. The majority of respondents experienced positive changes in their clinical course after using the application (83.1%) and were satisfied with the structure and completeness of the application (86.7%). Additionally, the respondents' answers indicated that the application was easy to use (96.7%) and recommendable to others (97.7%) and that they would continue using the application to manage their diabetes (96.7%). After using the Diabetes Notepad application, diabetes related self-care activities assessed by SDSCA displayed statistically significant improvements (P<0.05), except for the number of days of drinking. CONCLUSION: This smartphone-based application can be a useful tool leading to positive changes in diabetes related self-care activities and increase user satisfaction.

Celiac Disease in a Predisposed Subject (HLA-DQ2.5) with Coexisting Graves' Disease

Celiac disease is an intestinal autoimmune disorder, triggered by ingestion of a gluten-containing diet in genetically susceptible individuals. The genetic predisposition is related to human leukocyte antigen (HLA) class II genes, especially HLA-DQ2-positive patients. The prevalence of celiac disease has been estimated to be ~1% in Europe and the USA, but it is rarer and/or underdiagnosed in Asia. We report a case of celiac disease in a predisposed patient, with a HLA-DQ2 heterodimer, and Graves' disease that was treated successfully with a gluten-free diet. A 47-year-old woman complained of persistent chronic diarrhea and weight loss over a 9 month period. Results of all serological tests and stool exams were negative. However, the patient was found to carry the HLA DQ2 heterodimer. Symptoms improved after a gluten-free diet was initiated. The patient has been followed and has suffered no recurrence of symptoms while on the gluten-free diet. An overall diagnosis of celiac disease was made in a genetically predisposed patient (HLA-DQ2 heterodimer) with Graves' disease.

Insufficient Experience in Thyroid Fine-Needle Aspiration Leads to Misdiagnosis of Thyroid Cancer

BACKGROUND: Fine-needle aspiration (FNA) of the thyroid is a widely accepted confirmatory test for thyroid cancer with high sensitivity and specificity. FNA is a simple procedure that is learned by many clinicians to enable accurate diagnosis of thyroid cancer. However, it is assumed that because the FNA test is a relatively simple procedure, its cytologic results are reliable regardless of the operator's experience. The aim of this study was to evaluate the differences in the diagnostic indices of FNA between operators with different levels of experience. METHODS: A total of 694 thyroid FNA specimens from 469 patients were reviewed, and were separated based on the experience of the clinicians who performed the procedure. One hundred and ninety were categorized in the experienced group, and 504 in the inexperienced group. All FNA results were then compared with histological data from surgically resected specimens, and the sample adequacy and diagnostic accuracy of the groups were compared. RESULTS: The age, gender, and nodule size and characteristics were similar in both groups. The sample adequacy rate was not significantly different between the experienced and nonexperienced groups (96.3% vs. 95.4%, P=0.682). However, the non-experienced group had a higher false-negative rate than the experienced group (6.4% vs. 17.2%, P=0.038), and the sensitivity of the FNA test also tended to be lower in the nonexperienced group (95.6% vs. 88.9%, P=0.065). CONCLUSION: These results suggest that FNA operators who have less experience may miss cases of thyroid cancer by performing the procedure incorrectly. As such, the experience of the FNA operator should be considered when diagnosing thyroid cancer. When clinicians are being trained in FNA, more effort should be made to increase the accuracy of the procedure; therefore, enhanced teaching programs and/or a more detailed feedback system are recommended.

Serum Magnesium Level Is Associated with Type 2 Diabetes in Women with a History of Gestational Diabetes Mellitus: The Korea National Diabetes Program Study

Gestational diabetes mellitus (GDM) is a strong predictor of postpartum prediabetes and transition to overt type 2 diabetes (T2DM). Although many reports indicate that low magnesium is correlated with deteriorated glucose tolerance, the association between postpartum serum magnesium level and the risk for T2DM in women with a history of GDM has not been evaluated. We analyzed postpartum serum magnesium levels and development of prediabetes and T2DM in women with prior GDM according to American Diabetes Association (ADA) criteria using the Korean National Diabetes Program (KNDP) GDM cohort. During a mean follow-up of 15.6+/-2.0 months after screening, 116 women were divided into three groups according to glucose tolerance status. Ultimately, eight patients (6.9%) were diagnosed with T2DM, 59 patients (50.9%) with prediabetes, and 49 patients (42.2%) with normal glucose tolerance (NGT) after follow-up. The T2DM group had the lowest serum magnesium level (0.65 [0.63-0.68] mM/L) in the postpartum period, but there was no significant difference between the prediabetes group (0.70 [0.65-0.70] mM/L) and the NGT group (0.70 [0.65-0.70] mM/L) (P=0.073) Multiple logistic regression analysis showed that postpartum HOMA-IR was a significant predictor of both prediabetes and T2DM. Moreover, we found that postpartum serum magnesium level was also a possible predictor for T2DM development. Serum magnesium level in the postpartum period may be a possible predictor for T2DM development in women with a history of GDM.