Prevalence of chronic complications in korean patients with type 2 diabetes mellitus based on the korean national diabetes program

The Association of Smoking Status with Diabetic Microvascular Complications in Korean Patients with Type 2 Diabetes

PURPOSE

Few studies have investigated the association between smoking and microvascular complications in the Asian population with type 2 diabetes mellitus (T2DM). We aimed to investigate the relationship between smoking status and microvascular complications in Korean patients with T2DM.

MATERIALS AND METHODS

From the Korean National Diabetes Program cohort, we included 2316 Korean male with T2DM who had baseline clinical information available, including their smoking status, and underwent diabetic complication studies.

RESULTS

Compared to non-smokers, current smokers had higher odds of any-microvascular complications [adjusted odds ratio (aOR) 1.45, 95% confidence interval (CI) 1.07-1.97, p=0.016]. The odds of neuropathy were significantly higher; however, the odds of retinopathy were significantly lower in current smokers than in nonsmokers (all p<0.05). Among those who underwent repeated complication tests after 3 years, the risk of newly developed retinopathy was significantly increased in ex-smokers [aOR 3.77 (95% CI 1.61-8.87), p=0.002]. Within ex-smokers, long smoking duration and smoking cessation within the recent 5 years were associated with an increased risk of newly developed retinopathy (all p<0.05).

CONCLUSION

Male smokers had higher odds of having overall diabetic microvascular complications, including neuropathy. However, the odds of having retinopathy were significantly lower among current smokers. More attention and research are needed regarding the increased risk of retinopathy development in ex-smokers who have recently stopped smoking after a long history of smoking.

Impact of diabetes distress on glycemic control and diabetic complications in type 2 diabetes mellitus

The effect of diabetes distress on glycemic control and its association with diabetes complications is still poorly understood. We aimed to study the clinical features of patients with high diabetes distress, focusing on changes in glycemic control and risk of diabetic complications. From the Korean National Diabetes Program data, we investigated 1862 individuals with type 2 diabetes mellitus (T2DM) who completed diabetic complication studies and the Korean version of the Problem Areas in Diabetes Survey (PAID-K). A total score of PAID-K ≥ 40 was considered indicative of high distress. Individuals with high distress (n = 589) had significantly higher levels of glycated hemoglobin than those without distress (7.4% vs. 7.1%, p < 0.001). This trend persisted throughout the 3-year follow-up period. Higher PAID-K scores were associated with younger age, female gender, longer duration of diabetes, and higher carbohydrate intake (all p < 0.05). There was a significant association between high distress and diabetic neuropathy (adjusted odds ratio, 1.63; p = 0.002), but no significant association was found with other complications, including retinopathy, albuminuria, and carotid artery plaque. In conclusion, high diabetes distress was associated with uncontrolled hyperglycemia and higher odds of having diabetic neuropathy.

Clinical and economic impact of changing reimbursement criteria for statin treatment among patients with type 2 diabetes mellitus in South Korea

Aim: Patients with type 2 diabetes mellitus (T2DM) in South Korea can be reimbursed for statins if they have a low-density lipoprotein cholesterol (LDL-C) level of ≥100 mg/dL. We aimed to explore the clinical and economic benefit received by T2DM patients when easing the current criteria for statin treatment by lowering the LDL-C threshold from 100 mg/dL to 70 mg/dL.

Methods: We used a static course model with a 5-year period to compare the following two scenarios in T2DM patients with no history of cardiovascular (CV) events: the current criteria covering LDL-C ≥100 mg/dL and the revised criteria covering LDL-C ≥70 mg/dL. The number of target patients was estimated based on previous Korean studies on patients with T2DM. The current mix of treatments used for T2DM and costs involving CV events were estimated using the National Health Insurance Service–National Health Screening Cohort database. The baseline CV event rates and case fatality were estimated using NHIS Customized database, including 50% patients who were prescribed atorvastatin and 100% who were not prescribed statins between 2009 and 2012 among patients with T2DM in the entire Korean population. After propensity score matching, patients with T2DM not prescribed statins were followed up until 2018 to estimate the incidence rates of coronary heart disease (CHD) and stroke. The efficacy of atorvastatin for the primary prevention of CV events in patients with T2DM was derived from a pivotal clinical trial. The outcome measures were the number of CV events prevented after the change in criteria and the consequent cost savings.

Results: In South Korea, the current and revised criteria covered 2,434,379 and 3,446,149 patients with T2DM, respectively. The change in criteria resulted in the prevention of 726 CV events and cost savings of US dollars (USD) 5.5 million at the national level and USD 0.0089 per member per month in the fifth year.

Conclusion: Easing the reimbursement criteria for statin treatment among patients with T2DM was associated with a reduction in CV events and their related costs; therefore, changing the reimbursement criteria is worth further consideration to mitigate the burden of CV disease.

Dietary glutamic acid and aspartic acid as biomarkers for predicting diabetic retinopathy

The screening rate of diabetic retinopathy (DR) is low despite the importance of early diagnosis. We investigated the predictive value of dietary glutamic acid and aspartic acid for diagnosis of DR using the Korea National Diabetes Program cohort study. The 2067 patients with type 2 diabetes without DR were included. The baseline intakes of energy, glutamic acid and aspartic acid were assessed using a 3-day food records. The risk of DR incidence based on intake of glutamic acid and aspartic acid was analyzed. The DR group was older, and had higher HbA1c, longer DM duration, lower education level and income than non-DR group (all p < 0.05). The intake of total energy, glutamic acid and aspartic acid were lower in DR group than non-DR group (p = 0.010, p = 0.025 and p = 0.042, respectively). There was no difference in the risk of developing DR according to the intake of glutamic acid and ascorbic acid. But, aspartic acid intake had a negative correlation with PDR. Hence, the intake of glutamic acid and aspartic acid did not affect in DR incidence. However, lower aspartic acid intake affected the PDR incidence.

Perioperative anesthetic management of patients with diabetes mellitus: focused on blood glucose control

Diabetes mellitus is the most common metabolic disease characterized by elevated blood glucose, which results in damage to the heart, blood vessels, eyes, kidney, and nervous system. The incidence of diabetes mellitus has increased in Korea due to longer life expectancy or lifestyle improvement. Since diabetes affects multiple organs including the cardiovascular, neuroendocrine, and autonomic nervous systems, the risk of postoperative complications such as wound infection and cardiovascular events might be increased in patients with diabetes. In addition to postoperative complications, hypoglycemia or hyperglycemia in diabetes may also cause serious problems during surgery. Preoperative fasting and surgical stress may contribute to the derangement of the patient’s physiological status. For appropriate management of diabetic patients in the perioperative period, patients should be evaluated in detail preoperatively and their blood glucose levels should be checked repeatedly during the surgery and even after surgery. The present paper reviews preoperative, intraoperative, and postoperative management of patients with diabetes.

Predicting Old-age Mortality Using Principal Component Analysis: Results from a National Panel Survey in Korea

Background and Objectives: This study aimed to group diseases classified by the International Classification of Diseases using principal component analysis, and discuss a systematic approach to reducing the preventable death rate from a perspective of public health. Materials and Methods: Using a 10-year follow-up analysis of the Korean Longitudinal Study of Aging (KLoSA) data, this study obtained de-identified data including participants’ data of community-dwelling individuals aged ≥45 years from 2006 to 2016. Participants were randomly selected using a multistage, stratified probability sampling based on geographical area and housing type. We excluded 37 participants with missing information at baseline and included 10,217 study participants. This study used the principal component analysis to extract comorbidity patterns, and chi-square test and Cox proportional hazards models for analyzing the association between the factors of interest. Results: Principal component 1 (diabetes, heart disease, and hypertension) was associated with an increased hazard ratio (HR) of 1.079 (95% confidence interval (CI) 1.031–1.129, p = 0.001). Principal component 3 (psychiatric and cerebrovascular diseases) was related to an increased HR of 1.134 (95% CI 1.094–1.175, p < 0.0001). Moreover, principal component 4 was associated with a high HR of 1.172 (95% CI 1.130–1.215, p < 0.0001). However, among participants aged between 45 and 64 years, principal component 4 showed a meaningfully increased HR of 1.262 (95% CI 1.184–1.346, p < 0.001). In this study, among the four principal components, three were statistically associated with increased mortality. Conclusions: The principal component analysis for predicting mortality may become a useful tool, and artificial intelligence (AI) will improve a value-based healthcare strategy, along with developing a clinical decision support model.

Clinical Characteristics and Prevalence of Comorbidities according to Metformin Use in Korean Patients with Type 2 Diabetes

METHODS

This cross-sectional study based on the Korean National Diabetes Program 2 registry used its baseline clinical data collected from seven participating university hospitals in Korea. Patients with no significant changes in their oral hypoglycemic agents and no diabetes-related complications within the year prior to participation were enrolled. Patients' clinical characteristics according to metformin use were analyzed.

RESULTS

Among 858 subjects included in the analyses, 706 were metformin users and 152 were nonmetformin users. Metformin users were significantly younger and had higher and glycated hemoglobin with significantly lower rates of accompanying microvascular complications such as retinopathy, cataracts, overt proteinuria, renal insufficiency, and peripheral neuropathy than nonusers. Meanwhile, there was a significantly lower prevalence of malignancy and depression among metformin users. These associations remained significant in multivariate analyses. The prevalence rate of macrovascular complications was not significantly different between the two groups.

CONCLUSIONS

There were significant differences with respect to clinical characteristics and comorbidity prevalence according to metformin use among Korean type 2 diabetes patients. Long-term follow-up of these patients is necessary to observe how this difference will affect clinical outcomes for these patients.

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.

Randomized control trial comparing the effect of cilostazol and aspirin on changes in carotid intima-medial thickness

Antiplatelet drugs are effective in preventing recurrence of atherosclerosis in type 2 diabetes (T2D) patients. However, the efficacy and usefulness of antiplatelet drugs on the progression of carotid intima-media thickness (IMT), a marker for evaluating early atherosclerotic vascular disease, has not been analyzed. We conducted a prospective, randomized, open, 36-month trial comparing cilostazol vs. aspirin. A total of 415 T2D patients (age range 38-83 years; 206 females) without macrovascular complications were randomized to either an aspirin (100 mg/day) or cilostazol (200 mg/day) treatment. Patients underwent B-mode ultrasonography annually to assess the IMT and serum levels of inflammatory markers were measured before and after each treatment. Potential confounders were statistically adjusted, and included lipid profiles, HbA1c, body mass index, waist circumference, anti-hypertensive and statin medications. The decrease in mean left, maximum left, mean right and maximum right IMT were significantly greater with cilostazol compared with aspirin (- 0.094 ± 0.186 mm vs. 0.006 ± 0.220 mm, p < 0.001; - 0.080 ± 0.214 mm vs. 0.040 ± 0.264 mm, p < 0.001; - 0.064 ± 0.183 mm vs. 0.004 ± 0.203 mm, p = 0.015; - 0.058 ± 0.225 mm vs. 0.023 ± 0.248 mm, p = 0.022, respectively). And these differences remained significant after adjustment of potential confounders. Compared with aspirin, cilostazol treatment was associated with significantly increased HDL cholesterol (p = 0.039) and 25-hydroxy vitamin D levels (p = 0.001). Cilostazol treatment was associated with significantly lowered IMT in T2D patients compared to aspirin, independent of conventional cardiovascular risk factors. Cilostazol may inhibit plaque formation and have beneficial effects on atherosclerosis through vasodilatory and antiplatelet effects.

Genome-wide association study identifies new susceptibility loci for diabetic nephropathy in Korean patients with type 2 diabetes mellitus

Genetic factors are considered to be important in the pathogenesis of diabetic nephropathy (DN). Despite several genome-wide association studies (GWASs) demonstrating that specific polymorphisms of candidate genes were associated with DN, there were some limitations in previous studies. We conducted a GWAS using customized DNA chips to identify novel susceptibility loci for DN in Korean. We analyzed a total of 414 DN cases and 474 normoalbuminuric diabetic hyper-controls across two stages using customized DNA chips containing 98 667 single nucleotide polymorphisms (SNPs). We explored the associations between SNPs and DN in samples from 87 DN cases, mostly confirmed by renal biopsy, and 104 diabetic hyper-controls, and replicated these associations in independent cohort samples with 327 DN cases and 370 diabetic hyper-controls. The top significant SNPs from the discovery samples were selected for replication in the independent cohort. rs3765156 in PIK3C2B was significantly associated with DN in the replication cohort after multiple test. The SNPs identified in our study provide new insights into the pathogenesis of DN in the Korean population. Additional studies are needed to determine biological effects and clinical utility of our findings.

Implementation of the Chronic Disease Care System and its association with health care costs and continuity of care in Korean adults with type 2 diabetes mellitus

Background

The Chronic Disease Care System (CDCS) has been implemented in Korea to encourage treatment continuity in chronic disease patients. This study investigated the effect of the introduction of the CDCS on health care costs and continuity of care in individuals with type 2 diabetes mellitus (T2DM).

Methods

The National Health Insurance data from August, 2010 to March, 2012 (pre-policy) and from May, 2012 to December, 2013 (post-policy) were used. Introduction of the CDCS was defined as the intervention. The intervention group consisted of T2DM patients participating in the program and the control group patients not participating in the program. The Difference-in-Differences (DID) method was used to estimate the differences in total health care costs for outpatient services and continuity of care between the intervention and the control group before and after the intervention period.

Results

Implementation of the CDCS was associated with decreased health care costs (β = − 46,877 Korean Won, P < 0.0001) and improved continuity of care (β = 0.0536, P < 0.0001) in the intervention group with adjustment for covariates.

Conclusion

Findings confirm an association between the adoption of the CDCS and reduced health care costs and improved continuity of care. The results reveal the potential benefits of reinforcing effective chronic disease management strategies in reducing health care costs and improving treatment continuity.

Importance of family history of diabetes in computing a diabetes risk score in Korean prediabetic population

Prediabetic subjects represent a vulnerable population, requiring special care to reduce the risk of diabetes onset. We developed and validated a diabetes risk score for prediabetic subjects using the Korea National Diabetes Program (KNDP) cohort. Subjects included in the multicenter and prospective cohort (n = 1162) had high diabetes risk at baseline (2005) and were followed until 2012. Survival analysis was performed to analyze the prospective cohort over time, and the bootstrap method was used to validate our model. We confirmed our findings in an external cohort. A diabetes risk score was calculated and the cut-off defined using a receiver operating characteristic curve. Age, body mass index, total cholesterol, and family history of diabetes were associated with diabetes. The model performed well after correction for optimism (Cadj = 0.735). A risk score was defined with a cut-off of ≥5 that maximized sensitivity (72%) and specificity (62%), with an area under the curve of 0.73. Prediabetic subjects with a family history of diabetes had a higher probability of diabetes (risk score = 5) irrespective of other variables; this result was confirmed in the external cohort. Hence, prediabetic subjects with a family history of diabetes have a higher probability of developing diabetes, regardless of other clinical factors.

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.

Failure of monotherapy in clinical practice in patients with type 2 diabetes: The Korean National Diabetes Program

AIMS/INTRODUCTION

We investigated the failure of monotherapy in patients with type 2 diabetes mellitus in real practice settings.

MATERIALS AND METHODS

The Korean National Diabetes Program was a prospective, multicenter observational cohort study of type 2 diabetes mellitus patients in Korea. Of the 3,950 patients enrolled in the study, we studied 998 who were continuously maintained on monotherapy for at least 90 days at six participating centers. To balance the baseline characteristics of patients in each group, we used propensity matching at a 1:1 ratio (metformin vs sulfonylureas) and 4:1 ratio (metformin vs meglitinides and metformin vs alpha-glucosidase inhibitors [aGIs]). The hazard ratios (HRs) of treatments (compared with metformin) were determined by Cox's proportional hazards regression modeling.

RESULTS

The median follow-up time was 56 months, and monotherapy failed in 45% of all patients. The annual incidences of failure were 15.6%, 21.3%, 27% and 9.6% in the metformin, sulfonylurea, meglitinide and aGI groups. Compared with metformin, sulfonylureas and meglitinides were associated with higher risks of monotherapy failure (HR 1.39, 95% confidence interval [CI] 1.08-1.80; HR 1.92, 95% CI 1.13-3.27), and aGIs with risks similar to that of metformin (HR 0.80, 95% CI 0.44-1.45). When analyzed by failure type, sulfonylureas, meglitinides and aGIs were associated with a higher risk of a switch to other agents (HR 4.43, 95% CI 2.14-9.17; HR 18.80, 95% CI 6.21-56.93; HR 4.25, 95% CI 1.49-12.13), and aGIs with a lower risk of prescription of add-on second agents (HR 0.16, 95% CI 0.04-0.64).

CONCLUSIONS

Metformin was associated with a lower failure risk than were sulfonylureas and meglitinides, but a comparable aGI failure rate.

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.

Long-term effects on glycaemic control and β-cell preservation of early intensive treatment in patients with newly diagnosed type 2 diabetes: A multicentre randomized trial

AIM

To determine the effects of early intensive glycaemic control with intensive insulin treatment (IIT) or initial combined oral antidiabetic drug (COAD) therapy on long-term glycaemic control and the preservation of β-cell function in people with type 2 diabetes mellitus (T2DM).

METHODS

Newly diagnosed drug-naïve patients with T2DM from 8 outpatient diabetes centres were randomized to receive either IIT (n = 50; glargine/glulisine) or COAD (n = 47; glimepiride/metformin) as intensive treatment until the termination criteria to ensure euglycaemia were met. After intensive treatment, the patients completed a follow-up period with either lifestyle modification (LSM) alone or rescue therapy to maintain target glycated haemoglobin levels of <7% (53 mmol/mol) up to week 104. The primary outcomes were analysed after excluding participants who were anti-glutamic acid decarboxylase autoantibody-positive.

RESULTS

Both intensive treatment methods were effective for short-term glycaemic control, but improvements in the disposition index (DI) were significantly greater in the IIT group than in the COAD group (P = .021). During the follow-up period after intensive treatment, the two groups significantly differed in rescue method regarding the maintenance of comparable levels of glycaemic control (P = .010) and more participants who received IIT exhibited well-controlled glycaemia with LSM alone. Additionally, the IIT group maintained a higher DI than the COAD group during the follow-up period. Cox regression analysis showed that the IIT method was associated with a 52.5% lower risk of failing to maintain drug-free glycaemic remission compared with the COAD method (P = .015).

CONCLUSIONS

The findings indicate that outpatient clinic-based IIT to ensure euglycaemia in newly diagnosed patients with T2DM might be an effective initial therapeutic option for improvements in β-cell function and glycaemic control over the long term, without serious adverse events.

Characteristics of frequent emergency department users with type 2 diabetes mellitus in Korea

AIMS/INTRODUCTION

Frequent emergency department (ED) visitors are medically vulnerable individuals. We identified the characteristics of "frequent ED users" among Korean patients with type 2 diabetes mellitus.

MATERIALS AND METHODS

We used the Health Insurance Review and Assessment Service National Patient Sample, which is a nationally representative sample. Patients (n = 109,412) with type 2 diabetes mellitus as a primary or secondary diagnosis at one of their visits were included. Individuals were classified into three groups according to the number of ED visits: frequent (≥4 visits), occasional (<4 visits) and non-users of the ED. The characteristics of the patients that distinguished frequent users from the other groups were investigated.

RESULTS

Frequent ED users were mainly men (P < 0.001), with longer treatment duration (P < 0.001), more frequent comorbidities (cardiovascular and chronic kidney disease) and primary diagnosis made by surgery (P = 0.0028). They had higher mortality (P = 0.0085), longer hospitalization duration (P < 0.001), higher costs per visit (P < 0.001) and more often required medical protection (P < 0.001). These patients were treated more frequently with sulfonylurea, insulin, meglitinide and alpha-glucosidase inhibitors (P < 0.05).

CONCLUSIONS

The present findings suggest that frequent users of the ED with type 2 diabetes mellitus have serious health conditions, a poor socioeconomic situation and tend to take some medicines (sulfonylurea, etc.), which often are associated with hypoglycemia. Attention should be given to therapy, and to patients with renal and cardiovascular diseases to decrease the dependency of these patients on the ED.

Metformin reduces the risk of cancer in patients with type 2 diabetes: An analysis based on the Korean National Diabetes Program Cohort

The epidemiological literature suggests that insulin resistance, hyperinsulinemia, and increased levels of insulin-like growth factors place patients with type 2 diabetes mellitus (T2DM) at greater risk of cancer. The association between cancer incidence and the use of antidiabetic medications in patients with T2DM has been recently examined. There have been conflicting reports regarding an association between metformin and cancer risk. The aim of this study was to investigate the relationship between metformin use and the incidence of cancer in Koreans with T2DM.Data from The Korean National Diabetes Program (KNDP, 2006-2014), a nationwide, large-scale, prospective, multicenter cohort study in Korea, were used to study patients with T2DM. Patients ≥30 years old whose complete medical records were available were included in this study. Patients with a history of any cancer on KNDP registration or those who had been diagnosed with any type of cancer within 1 year of metformin use were excluded. Survival curves with respect to the incidence of cancer were plotted using the Kaplan-Meier method. Hazard ratios and 95% confidence intervals for cancer were estimated in a Cox proportional hazards regression analysis.During a mean 5.8 years of follow-up, 164 of the 1918 study patients (335 metformin nonusers and 1583 metformin users) developed cancer. The incidence per 1000 person-years was 21.8 in metformin nonusers and 13.2 in metformin users. Metformin users had a reduced risk of cancer, even after adjustment for demographic characteristics, metabolic parameters, diabetic complications, and other antidiabetic medications (hazard ratio 0.513, 95% confidence interval 0.318-0.826, P = .0060). Subgroup analysis of metformin users showed a reduced risk of cancer in males, patients < 65 years of age, patients with a T2DM duration < 5 years, nonobese patients, nonsmokers, and good glycemic control group.This large-scale, prospective, multicenter cohort study demonstrated an association between metformin use and reduced cancer risk in patients with T2DM.

Clinical characteristics and risk factors for retinal diabetic neurodegeneration in type 2 diabetes

AIMS

To identify clinical characteristics and risk factors of retinal neurodegeneration represented by macular ganglion cell/inner plexiform layer (mGCIPL) thinning in patients with long-standing type 2 diabetes mellitus (T2DM).

METHODS

Patients who had T2DM for >15 years were prospectively recruited from September 2014 to July 2015. Clinical data and samples were collected according to the Common Data Element and Standards of Procedure developed by the Korean Diabetes Association research council. Baseline characteristics included age, gender, family history, medical record of comorbidity, and microvascular complications. All patients underwent optical coherence tomography with automatic segmentation of the mGCIPL in six parafoveal regions. Multivariable regression analysis identified factors associated with mGCIPL thinning.

RESULTS

Of 220 registered patients, 162 were included after ophthalmologic examination. The mean (SD) age was 65.0 (9.3) years, the mean duration of T2DM was 20.5 (4.0) years; mGCIPL thickness was 76.2 (8.5) µm. Hypertension, diabetic retinopathy, statin medication, estimated glomerular filtration rate, conduction velocity of the posterior tibial, peroneal, and sural nerves, and cardiac autonomic neuropathy (CAN) score were significantly correlated with mGCIPL thickness. Multivariate regression analysis showed that the CAN score (coefficient = -1.78, p = 0.001) and sural nerve velocity (coefficient = 0.458, p = 0.035) yielded a significant high regression correlation with mGCIPL thickness (overall R ² = 0.46).

CONCLUSIONS

This study demonstrated that various clinical features were associated with retinal neurodegeneration in T2DM. In particular, peripheral nerve conduction and autonomic nerve function were confirmed to be strong risk factors for mGCIPL thinning in patients with T2DM.

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.

Clinical heterogeneity of type 1 diabetes (T1D) found in Asia

Diabetes mellitus among young patients in Asia is caused by a complex set of factors. Although type 1 diabetes (T1D) remains the most common form of diabetes in children, the recent unabated increase in obesity has resulted in the emergence of type 2 diabetes (T2D) as a new type of diabetes among adolescents and young adults. In addition to the typical autoimmune type 1 diabetes (T1aD) and T2D patients, there is a variable incidence of cases of non-autoimmune types of T1D associated with insulin deficiency (T1bD). Additional forms have been described, including fulminant T1D (FT1D). Although most diagnoses of T1D are classified as T1aD, fulminant T1D exists as a hyper-acute subtype of T1D that affects older children, without associated autoimmunity. Patient with this rare aetiology of diabetes showed a complete loss of β-cell secretory capacity without evidence of recovery, necessitating long-term treatment with insulin. In addition, latent autoimmune diabetes in adults is a form of autoimmune-mediated diabetes, usually diagnosed during the insulin-dependent stage that follows a non-insulin requiring phase, which can be diagnosed earlier based on anti-islet autoantibody positivity. Some reports discuss T1bD. Others are elaborating on the presence of "atypical T1b diabetes," such as Flatbush diabetes. The prevalence of diabetes mellitus in young adults continues to rise in Asian populations as T2D increases. With improved characterization of patients with diabetes, the range of diabetic subgroups will become even more diverse in the future. Distinguishing T1D, T2D, and other forms of diabetes in young patients is challenging in Asian populations, as the correct diagnosis is clinically important and has implications for prognosis and management. Despite aetiological heterogeneity in the usual clinical setting, early diagnosis and classification of patients with diabetes relying on clinical grounds as well as measuring islet autoantibodies and fasting plasma C-peptide could provide a possible viable method to minimize complications.

Hypoglycemia is associated with dementia in elderly patients with type 2 diabetes mellitus: An analysis based on the Korea National Diabetes Program Cohort

AIM

Although hypoglycemia is associated with cognitive dysfunction, including dementia, in patients with type 2 diabetes mellitus (DM), the data are equivocal. The purpose of this study was to investigate the association between hypoglycemia, dementia, and other cognitive dysfunctions.

METHODS

This was a prospective observational study based upon the Korea National Diabetes Program (KNDP). Among the 4540 participants in the KNDP cohort, individuals aged ⩾60years without any history of hypoglycemia or cognitive dysfunction (n=1957) were included. Nationally representative data from the Health Insurance Review and Assessment Service of Korea claim database were used to obtain a more precise determination of patient outcome.

RESULTS

During a mean follow-up period of 3.4±0.9years, 118 subjects experienced hypoglycemia-related events. The incidence of dementia and cognitive dysfunction was 7.5 cases per 1000 person-years (PY) and 0.61 cases per 1000 PY, respectively. In the subjects who experienced hypoglycemic events (relative to those who did not), the incidence of dementia was significantly higher (P=0.0139), but the incidence of cognitive dysfunction was not (P=0.1106). Hypoglycemic events were associated with dementia (HR, 2.689; 95% CI, 1.080-6.694, P=0.0335) following multiple adjustments. There was also a significant linear trend toward an increased dementia risk commensurate with an increasing number of hypoglycemic events (P=0.0286).

CONCLUSIONS

Hypoglycemia is significantly associated with the risk of dementia in Korean type 2 DM patients aged ⩾60years.

Elevated lipoprotein(a) levels predict cardiovascular disease in type 2 diabetes mellitus: a 10-year prospective cohort study

BACKGROUND/AIMS

Elevated lipoprotein(a) (Lp[a]) level is known to be a risk factor for cardiovascular disease (CVD). However, the data that has been reported on the association between the Lp(a) level and CVD in type 2 diabetes has been limited and incoherent. The aim of this study was to investigate the relationship between the Lp(a) concentration and new onset CVD in type 2 diabetes.

METHODS

From March 2003 to December 2004, patients with type 2 diabetes without a prior history of CVD were consecutively enrolled. CVD was defined as the occurrence of coronary artery disease or ischemic stroke. Cox proportional hazards models were used to identify the associations between the Lp(a) and CVD after adjusting for confounding variables.

RESULTS

Of the 1,183 patients who were enrolled, 833 participants were evaluated with a median follow-up time of 11.1 years. A total of 202 participants were diagnosed with CVD (24.2%). The median Lp(a) level for 1st and 4th quartile group was 5.4 (3.5 to 7.1) and 55.7 mg/dL (43.1 to 75.3). Compared with patients without CVD, those with CVD were older, had a longer duration of diabetes and hypertension, and used more insulin and angiotensin converting enzyme inhibitors/angiotensin receptor blockers at baseline. A Cox hazard regression analysis revealed that the development of CVD was significantly associated with serum Lp(a) level (hazard ratio, 1.92; 95% confidence interval [CI], 1.26 to 2.92; p < 0.001, comparing the 4th vs. 1st quartile of Lp[a]).

CONCLUSIONS

Elevated Lp(a) level was an independent predictable risk factor for CVD in type 2 diabetes. Other cardiovascular risk factors should be treated more intensively in type 2 diabetic patients with high Lp(a) levels.

Current status of managing diabetes mellitus in Korea

Diabetes mellitus is an increasing global health problem. Guidelines for diabetic care recommend management of lifestyle and risk factors (glucose, blood pressure, and cholesterol), as well as regular screening for complications associated with treatment of the conditions related to diabetes. The prevalence of diabetes increased from 8.6% to 11.0% from 2001 to 2013. According to the diabetes fact sheet 2015, the proportion of patients with diabetes treated with antihypertensive medications increased from 56.0% to 62.5% from 2006 to 2013, and 49.5% of those with diabetes were being treated with lipid-lowering medications in 2013, a 1.8-fold increase since 2006. According to the 2014 Korea National Health and Nutrition Examination Survey data, 45.6% of patients with diabetes achieved a hemoglobin A1c level of < 7.0%, 72.8% achieved a blood pressure of < 140/85 mmHg, and 58.0% achieved a low density lipoprotein cholesterol level of < 100 mg/dL. Only 19.7% of patients with diabetes had good control of all three of these parameters. Despite improvements in health promotion efforts, the rates of adherence to medication and risk-factor control are low. Therefore, a systematic approach to managing diabetes, including self-management education, is needed to prevent or delay complications. The government needs to establish a long-term policy to address the growing burden of diabetes.

Hypoglycemia and Medical Expenses in Patients with Type 2 Diabetes Mellitus: An Analysis Based on the Korea National Diabetes Program Cohort

Background and Aims

Hypoglycemia is one of the most important adverse events in individuals with type 2 diabetes mellitus (T2DM). However, hypoglycemia-related events are usually overlooked and have been documented less in clinical practice.

Materials and Methods

We evaluated the incidence, clinical characteristics, and medical expenses of hypoglycemia related events in T2DM patients based on the Korea National Diabetes Program (KNDP), which is the largest multi-center, prospective cohort in Korea (n = 4,350). For accurate outcomes, the KNDP data were merged with claims data from the Health Insurance Review and Assessment Service (HIRA) of Korea.

Results

During a median follow-up period of 3.23 years (95% CI: 3.14, 3.19), 88 subjects (2.02%) were newly diagnosed with hypoglycemia, and the incidence of hypoglycemia was 6.44 cases per 1,000 person-years (PY). Individuals with hypoglycemia were significantly older (59.7±10.7 vs. 53.3±10.4 years, p < 0.001), had more hospital visits (121.94±126.88 days/PY, p < 0.001), had a longer hospital stays (16.13±29.21 days/PY, p < 0.001), and incurred greater medical costs ($2,447.56±4,056.38 vs. $1,336.37±3,403.39 /PY, p < 0.001) than subjects without hypoglycemia.

Conclusion

Hypoglycemia-related events were infrequently identified among the medical records of T2DM subjects. However, they were associated significantly with poor clinical outcomes, and thus, hypoglycemia could have a substantial burden on the Korean national healthcare system.

Assessment of glycemic control in patients with type 2 diabetes mellitus treated with metformin-sulfonylurea combination: Results of a multicenter, cross-sectional, observational study in Korea

AIMS/INTRODUCTION

To assess the current status of glycemic control in patients with type 2 diabetes treated with a combination of metformin and sulfonylurea for >3 months, as measured by glycosylated hemoglobin (HbA1c).

MATERIALS AND METHODS

Data on patient demographics, diabetic complications, HbA1c, fasting plasma glucose (FPG) and type of treatment were collected in this multicenter, cross-sectional, non-interventional study.

RESULTS

From April 2008 to February 2009, 5,628 patients were recruited from 299 centers in Korea. Patients characteristics (mean ± SD) were as follows: age 58.4 ± 10.8 years, duration of diabetes 6.1 ± 4.7 years, body mass index 24.7 ± 2.9 kg/m(2), HbA1c 7.77 ± 1.22%, FBG 147.4 ± 46.5 mmol/L and FPG 164.0 ± 54.3 mmol/L. The most common diabetic complication was neuropathy (22.5%), followed by retinopathy (18.3%) and microalbuminuria (16.1%). Just 1,524 (27.1%) patients achieved HbA1c ≤7%. A higher number of patients (32.6%) treated by endocrinologists achieved HbA1c ≤7% than those treated by internists (24.4%) and primary care physicians (23.2%). In multivariate analyses, diabetic retinopathy (odds ratio 0.455, 95% confidence interval 0.341-0.606), nephropathy (odds ratio 0.639, 95% confidence interval 0.43-0.949), diabetes for ≥5 years (odds ratio 0.493, 95% confidence interval 0.4-0.606) and older age added by 1 year (odds ratio 1.019, 95% confidence interval 1.01-1.029) was significantly associated with achieving target HbA1c. In addition, treatment by endocrinologists rather than internists significantly increased chances of achieving target HbA1c (odds ratio 1.417, 95% confidence interval 1.146-1.751).

CONCLUSIONS

The majority of patients with type 2 diabetes in Korea had inadequate glycemic control, despite receiving a combination of metformin and sulfonylurea.

Low economic status is identified as an emerging risk factor for diabetes mellitus in korean men aged 30 to 59 years in korean national health and nutrition examination survey 2008 to 2010

BACKGROUND

We compared the association between economic status and the prevalence of diabetes mellitus (DM) using large nationwide datasets covering the previous 10 years in Korea.

METHODS

We analyzed the association between economic status and DM using Korean National Health and Nutrition Examination Survey (KNHANES) data from 2001 to 2010 weighted to represent the Korean population between 30 and 59 years of age. The economic status of participants was classified into quartiles according to monthly family income with an equivalence scale.

RESULTS

In men, the prevalence of diabetes in the lowest income quartile (Q1) was significantly higher than that in the other quartiles in 2008 (age and body mass index-adjusted odds ratio [OR], 1.846; 95% confidence interval [CI], 1.126 to 3.027; P=0.015), 2009 (OR, 1.706; 95% CI, 1.094 to 2.661; P=0.019), and 2010 (OR, 1.560; 95% CI, 1.024 to 2.377; P=0.039) but not in 2001 or 2005. The data indicated that classification in the lowest economic status was an independent risk factor for diabetes even after adjusting for abdominal obesity, dyslipidemia, hypertension and education level in men of KNHANES 2008 to 2010. Although economic status was significantly associated with abdominal obesity, hypertriglyceridemia, and hypertension in women (P<0.001), there was no significant association between economic status and DM in women.

CONCLUSION

Korean men between 30 and 59 years of age with the lowest economic status had a significantly higher prevalence of DM in 2008 to 2010 even after adjusting for other risk factors.

Heart rate variability in children with type 1 diabetes mellitus

OBJECTIVE

To gather current information about the effects of type 1 diabetes mellitus on children's cardiac autonomic behavior.

DATA SOURCES

The search of articles was conducted on PubMed, Ibecs, Medline, Cochrane, Lilacs, SciELO and PEDro databases using the MeSH terms: "autonomic nervous system", "diabetes mellitus", "child", "type 1 diabetes mellitus", "sympathetic nervous system" and "parasympathetic nervous system", and their respective versions in Portuguese (DeCS). Articles published from January 2003 to February 2013 that enrolled children with 9-12 years old with type 1 diabetes mellitus were included in the review.

DATA SYNTHESIS

The electronic search resulted in four articles that approached the heart rate variability in children with type 1 diabetes mellitus, showing that, in general, these children present decreased global heart rate variability and vagal activity. The practice of physical activity promoted benefits for these individuals.

CONCLUSIONS

Children with type 1 diabetes mellitus present changes on autonomic modulation, indicating the need for early attention to avoid future complications in this group.

Development of an HbA1c-based conversion equation for estimating glycated albumin in a Korean population with a wide range of glucose intolerance

Background

Compared to the golden standard glycation index of HbA1c, glycated albumin (GA) has potentials for assessing insulin secretory dysfunction and glycemic fluctuation as well as predicting diabetic vascular complications. However, the reference ranges of GA and a conversion equation need to be clearly defined. We designed this study to determine the reference ranges in patients with normal glucose tolerance (NGT) based on conventional measures of glycemic status and to devise a conversion equation for calculating HbA1c and GA in a Korean population.

Methodology/Principal Findings

In this multicenter, retrospective, cross-sectional study, we recruited antidiabetic drug-naïve patients with available glycemic variables including HbA1c, GA, and fasting plasma glucose regardless of glucose status. For the reference interval of serum GA, 5^th to 95^th percentile value of GA in subjects with NGT was adopted. The conversion equation between HbA1c and GA was devised using an estimating regression model with unknown break-points method. The reference range for GA was 9.0–14.0% in 2043 subjects. The 95^th percentile responding values for FPG, and HbA1c were approximately 5.49 mmol/l, and 5.6%, respectively. The significant glycemic turning points were 5.868% HbA1c and 12.2% GA. The proposed conversion equation for below and above the turning point were GA (%) = 6.960+0.8963 × HbA1c (%) and GA (%) = −9.609+3.720 × HbA1c (%), respectively.

Conclusions/Significance

These results should be helpful in future studies on the clinical implications of high GA relative to HbA1c and the clinical implementation of diabetes management.

Clinical and economic outcomes in medication-adherent and -nonadherent patients with type 2 diabetes mellitus in the Republic of Korea

BACKGROUND

The prevalence and social burden of type 2 diabetes mellitus (T2DM) is increasing. Medication adherence is necessary for positive outcomes in patients with T2DM.

OBJECTIVE

This study evaluated the association between medication adherence and clinical/economic outcomes in patients with T2DM in the Republic of Korea over a 3-year period.

METHODS

This study used data from the Korean National Diabetes Program at 5 hospitals. Medication possession ratios of ≥90% and <90% were used to define adherent and nonadherent groups, respectively. The degree of glycemic control, changes in blood pressure and lipid profiles, and health care costs were compared.

RESULTS

Of the 608 patients, 472 were medication adherent and 136 were nonadherent. The adherent patients displayed improved fasting blood glucose and hemoglobin A1c during the study. Diastolic blood pressure and total cholesterol were lower at 36 months, and lower low-density lipoprotein cholesterol was noted at baseline and 24 months. The total health care costs were $1861, $2060, and $1924, respectively, versus $1617, $1751, and $1602 during the 3-year study period for the adherent group versus the nonadherent group, respectively (P = 0.316, 0.627, and 0.172, respectively), whereas the outpatient drug costs were $1143, $1176, and $1162 in the adherent group versus $925, $778, and $914 in the nonadherent group (P = 0.002, P < 0.001, and P = 0.001).

CONCLUSIONS

The adherent patients displayed better glycemic control and lipid profiles. Medication-related expenses were higher in the adherent group, but overall health care costs, including hospitalization costs, were similar between the 2 groups.

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.

Prevalence and factors associated with diabetic retinopathy in a Korean adult population: the 2008-2009 Korea National Health and Nutrition Examination Survey

AIM

We examined the prevalence and factors associated with diabetic retinopathy (DR) in a Korean adult population.

METHODS

Fundus examination data from 10,345 people in the fourth Korea National Health and Nutrition Examination Survey from 2008 to 2009 were examined. For each participant, one 45° nonmydriatic digital retinal image, centered on the fovea, was taken per eye. DR was defined as the presence of one or more retinal microaneurysms or retinal blot hemorrhages with or without more severe lesions.

RESULTS

The weighted prevalence of DR was 0.9% (95% CI, 0.7-1.1) in a Korean adult population and 11.0% (95% CI, 8.9-13.6) in Korean adults with diabetes. In a logistic regression analysis, only HbA1c and diabetes duration were independently associated with DR; the other variables examined, including age, gender, exercise, current smoking, heavy alcohol drinking, presence of hypertension, total cholesterol, triglycerides, high-density lipoprotein cholesterol, anti-lipid medication, oral anti-diabetes treatment, and insulin treatment, were not associated with DR.

CONCLUSIONS

According to these national survey data, 1 in 10 people with diabetes has diabetic retinopathy. Glycemic control is the most important factor for preventing retinopathy in patients with diabetes.

Implication of circulating omentin-1 level on the arterial stiffening in type 2 diabetes mellitus

Omentin-1 is an adipokine implicated in diabetes, inflammation, and cardiovascular disease. However, no prospective studies have examined the impact of circulating omentin-1 levels on arterial stiffening in patients with type 2 diabetes mellitus. For the purpose of this study, we recruited 120 patients with type 2 diabetes mellitus and measured serum omentin-1, adiponectin, and high-sensitivity C-reactive protein levels as well as other cardiovascular risk factors. Arterial stiffness was assessed by brachial ankle pulse wave velocity (baPWV). An increase in the level of circulating omentin-1 over a period of 1 year was positively correlated with changes in levels of HbA1c and serum adiponectin as well as baPWV. Subjects with higher baseline serum omentin-1 levels tended to have a reduced arterial stiffness after 1 year (P for linear trend = 0.03). In the group with increased baPWV after 1 year, the magnitude of increase of circulating omentin-1 levels was significantly higher than in the group with a lower baPWV after 1 year (134.3 [16.6, 277.1] ng/mL vs. 15.9 [-67.6, 145.7] ng/mL, P < 0.01). Multiple stepwise logistic regression analysis revealed that an increase in systolic blood pressure and an increase in serum omentin-1 level were independently correlated with arterial stiffening, even after adjusting for other cardiovascular risk factors and medication history. Baseline serum omentin-1 levels can predict arterial stiffness changes occurring within a year. Furthermore, changes in serum omentin-1 levels after a year can function as independent markers of arterial stiffening in patients with type 2 diabetes mellitus.

Hemoglobin a1c may be an inadequate diagnostic tool for diabetes mellitus in anemic subjects

BACKGROUND

Recently, a hemoglobin A1c (HbA1c) level of 6.5% has been determined to be a criterion for diabetes mellitus (DM), and it is a widely used marker for the diagnosis of DM. However, HbA1c may be influenced by a number of factors. Anemia is one of the most prevalent diseases with an influence on HbA1c; however, its effect on HbA1c varies based on the variable pathophysiology of anemia. The aim of this study was to determine the effect of anemia on HbA1c levels.

METHODS

Anemic subjects (n=112) and age- and sex-matched controls (n=217) who were drug naive and suspected of having DM were enrolled. The subjects underwent an oral glucose tolerance test and HbA1c simultaneously. We compared mean HbA1c and its sensitivity and specificity for diagnosing DM between each subgroup.

RESULTS

Clinical characteristics were found to be similar between each subgroup. Also, when glucose levels were within the normal range, the difference in mean HbA1c was not significant (P=0.580). However, when plasma glucose levels were above the diagnostic cutoff for prediabetes and DM, the mean HbA1c of the anemic subgroup was modestly higher than in the nonanemic group. The specificity of HbA1c for diagnosis of DM was significantly lower in the anemic subgroup (P<0.05).

CONCLUSION

These results suggest that the diagnostic significance of HbA1c might be limited in anemic patients.

Increasing achievement of the target goals for glycemic, blood pressure and lipid control for adults with diagnosed diabetes in Korea

Aims/Introduction

We investigated the prevalence, treatment and control of diagnosed diabetes in Korean adults from 1998 to 2010.

Materials and Methods

The Korean Ministry of Health and Welfare carried out the Korean National Health and Nutrition Examination Survey (KNHANES) in the years 1998 (I), 2001 (II), 2005 (III), 2007–2009 (IV) and 2010 (V). We estimated the prevalence of diagnosed diabetes in Korean adults and the proportions of well‐controlled diabetes, as defined by having glycosylated hemoglobin <7.0%, blood pressure <130/80 mmHg and low density lipoprotein (LDL) cholesterol <100 mg/dL according to the American Diabetes Association.

Results

The prevalence of diagnosed diabetes increased significantly from 3.2% in 1998 to 6.4% in 2010 (P < 0.0001). The prevalence of adults with diagnosed diabetes achieving blood pressure and LDL cholesterol target levels increased from 23.8% to 54.2% (P < 0.0001), and 25.7% to 47.7% (P<0.0001), respectively. However, the percentage of patients achieving glycemic goals did not increase significantly from 42.5% to 49.1% (P = 0.3034). Furthermore, there were significant increases in the proportions of individuals achieving all three target levels, from 2.7% in 2005 to 8.7% in 2010 (P < 0.0001).

Conclusions

The prevalence of diagnosed diabetes in Korea increased significantly from 1998 to 2010. The percentages of those achieving all recommendations of the American Diabetes Association have increased, but are still not satisfactory.

Comparison of two creatinine-based equations for predicting decline in renal function in type 2 diabetic patients with nephropathy in a korean population

Aim. To compare two creatinine-based estimated glomerular filtration rate (eGFR) equations, the chronic kidney disease epidemiology collaboration (CKD-EPI) and the modification of diet in renal disease (MDRD), for predicting the risk of CKD progression in type 2 diabetic patients with nephropathy. Methods. A total of 707 type 2 diabetic patients with 24 hr urinary albumin excretion of more than 30 mg/day were retrospectively recruited and traced until doubling of baseline serum creatinine (SCr) levels was noted. Results. During the follow-up period (median, 2.4 years), the CKD-EPI equation reclassified 10.9% of all MDRD-estimated subjects: 9.1% to an earlier stage of CKD and 1.8% to a later stage of CKD. Overall, the prevalence of CKD (eGFR < 60 mL/min/1.73 m(2)) was lowered from 54% to 51.6% by applying the CKD-EPI equation. On Cox-regression analysis, both equations exhibited significant associations with an increased risk for doubling of SCr. However, only the CKD-EPI equation maintained a significant hazard ratio for doubling of SCr in earlier-stage CKD (eGFR ≥ 45 mL/min/1.73 m(2)), when compared to stage 1 CKD (eGFR ≥ 90 mL/min/1.73 m(2)). Conclusion. In regard to CKD progression, these results suggest that the CKD-EPI equation might more accurately stratify earlier-stage CKD among type 2 diabetic patients with nephropathy than the MDRD study equation.

C1q/TNF-related protein-3 (CTRP-3) and pigment epithelium-derived factor (PEDF) concentrations in patients with type 2 diabetes and metabolic syndrome

Recent studies have suggested that a novel adipokine, C1q/tumor necrosis factor-related protein-3 (CTRP-3), a paralog of adiponectin, may play an important role in the regulation of glucose metabolism and innate immunity. Pigment epithelium-derived factor (PEDF), a multifunctional protein with antioxidant and anti-inflammatory properties, is associated with insulin resistance and metabolic syndrome. We examined circulating CTRP-3 and PEDF concentrations in 345 subjects with diverse glucose tolerance statuses. Furthermore, we evaluated the involvement of CTRP-3 and PEDF with cardiometabolic risk factors including insulin resistance, high-sensitivity C-reactive protein (hsCRP), estimated glomerular filtration rate (eGFR), and brachial-ankle pulse wave velocity (baPWV). CTRP-3 concentrations were significantly higher in patients with type 2 diabetes or prediabetes than the normal glucose tolerance group, whereas PEDF levels were not different. Subjects with metabolic syndrome showed significantly higher levels of both CTRP-3 and PEDF compared with subjects without metabolic syndrome. Both CTRP-3 and PEDF were significantly associated with cardiometabolic parameters, including waist-to-hip ratio, triglycerides, HDL-cholesterol, alanine aminotransferase, eGFR, hsCRP, and baPWV. In conclusion, circulating CTRP-3 concentrations were elevated in patients with glucose metabolism dysregulation. Both CTRP-3 and PEDF concentrations were increased in subjects with metabolic syndrome and associated with various cardiometabolic risk factors.

Association between nutrient intake and obesity in type 2 diabetic patients from the Korean National Diabetes Program: a cross-sectional study

The aim of the study was to assess the association between usual dietary nutrient intake and obesity in Korean type 2 diabetic patients. We examined 2,832 type 2 diabetic patients from the Korean National Diabetes Program cohort who completed dietary assessment and clinical evaluation in this cross-sectional study. In men, higher dietary fiber intake was associated with a lower odds of being obese (P(trend) = 0.003) and in women, higher protein intake was associated with a lower odds of being obese (P(trend) = 0.03) after adjustment for age, diabetes duration, HbA1c, alcohol drinking, income, education level, and calorie intake. In men, higher fiber intake was associated with lower odds of obesity after further adjustment for diastolic blood pressure, physical activity, and possible confounding nutritional intake and medication. The multivariable adjusted odds ratio for the highest quintile of fiber intake was 0.37 (P(trend) < 0.001). In women, protein intake was not associated with obesity after further adjustment. In conclusion, higher intake of dietary fiber is associated with lower odds of being obese in type 2 diabetic men, suggesting a role for dietary fiber in the management and prevention of obesity in type 2 diabetes (ClinicalTrials.gov: NCT 01212198).

Direct medical costs for patients with type 2 diabetes and related complications: a prospective cohort study based on the Korean National Diabetes Program

We analyzed the direct medical costs for Korean patients with type 2 diabetes according to the type of complications and the number of microvascular complications. We analyzed costs for type 2 diabetes and associated complications in 3,125 patients. These data were obtained from the Korean National Diabetes Program (KNDP), a large, ongoing, prospective cohort study that began in 2005. The cost data were prospectively collected, using an electronic database, for the KNDP cohort at six hospitals. The costs were analyzed according to complications for 1 yr from enrollment in the study. Among 3,125 patients, 918 patients had no vascular complications; 1,883 had microvascular complications only; 51 had macrovascular complications only; and 273 had both complications. The annual direct medical costs for a patient with only macrovascular, only microvascular, or both macrovascular and microvascular complications were 2.7, 1.5, and 2.0 times higher than the medical costs of patients without complications. Annual direct medical costs per patient increased with the number of microvascular complications in patients without macrovascular complications. The economic costs for type 2 diabetes are attributable largely to the management of microvascular and macrovascular complications. Proper management of diabetes and prevention of related complications are important for reducing medical costs.

Epidemiology of micro- and macrovascular complications of type 2 diabetes in Korea

The prevalence of diabetes in Korea has increased six- to sevenfold over the past 40 years with its complications becoming major causes of morbidity and mortality. The rate of death among patients with diabetes is about twice as high as that among persons without diabetes and the most common cause of death is cardiovascular disease (30.6%). Despite the seriousness of diabetic complications, 30 to 70% of patients receive inadequate care, and only 40% of treated diabetic patients achieve the optimal control with HbA1c level <7% in Korea. In 2006, over 30 to 40% of patients with diabetes have microvascular complications and around 10% of them have macrovascular complications from our national data. Despite there are some debates about intensive glycemic control resulting in the deterioration of macrovascular complication, multifactorial treatment approaches including proper glycemic control are important to prevent diabetic complications. There have been needs for finding proper biomarkers for predicting diabetic complications properly but we still need more longitudinal studies to find this correlation with causal relationship. In this article, we wanted to review the recent status of micro- and macrovascular complications of type 2 diabetes in Korea from integration of many epidemiologic studies.