BackgroundThe National Health Insurance Service (NHIS) recently signed an agreement to provide limited open access to the databases within the Korean Diabetes Association for the benefit of Korean subjects with diabetes. Here, we present the history, structure, contents, and way to use data procurement in the Korean National Health Insurance (NHI) system for the benefit of Korean researchers.MethodsThe NHIS in Korea is a single-payer program and is mandatory for all residents in Korea. The three main healthcare programs of the NHI, Medical Aid, and long-term care insurance (LTCI) provide 100% coverage for the Korean population. The NHIS in Korea has adopted a fee-for-service system to pay health providers. Researchers can obtain health information from the four databases of the insured that contain data on health insurance claims, health check-ups and LTCI.ResultsMetabolic disease as chronic disease is increasing with aging society. NHIS data is based on mandatory, serial population data, so, this might show the time course of disease and predict some disease progress, and also be used in primary and secondary prevention of disease after data mining.ConclusionThe NHIS database represents the entire Korean population and can be used as a population-based database. The integrated information technology of the NHIS database makes it a world-leading population-based epidemiology and disease research platform.

In 2014, the National Health Insurance Service (NHIS) signed a memorandum of understanding with the Korean Diabetes Association to provide limited open access to its databases for investigating the past and current status of diabetes and its management. NHIS databases include the entire Korean population; therefore, it can be used as a population-based nationwide study for various diseases, including diabetes and its complications. This report presents how we established the analytic system of nation-wide population-based studies using the NHIS database as follows: the selection of database study population and its distribution and operational definition of diabetes and patients of currently ongoing collaboration projects.

Ursolic acid (UA) is a natural triterpene compound found in various fruits and vegetables. There is a growing interest in UA because of its beneficial effects, which include anti-inflammatory, anti-oxidant, anti-apoptotic, and anti-carcinogenic effects. It exerts these effects in various tissues and organs: by suppressing nuclear factor-kappa B signaling in cancer cells, improving insulin signaling in adipose tissues, reducing the expression of markers of cardiac damage in the heart, decreasing inflammation and increasing the level of anti-oxidants in the brain, reducing apoptotic signaling and the level of oxidants in the liver, and reducing atrophy and increasing the expression levels of adenosine monophosphate-activated protein kinase and irisin in skeletal muscles. Moreover, UA can be used as an alternative medicine for the treatment and prevention of cancer, obesity/diabetes, cardiovascular disease, brain disease, liver disease, and muscle wasting (sarcopenia). In this review, we have summarized recent data on the beneficial effects and possible uses of UA in health and disease managements.

Alternative splicing (AS) of protein-coding messenger RNAs is an essential regulatory mechanism in eukaryotic gene expression that controls the proper function of proteins. It is also implicated in the physiological regulation of mitochondria and various ion channels. Considering that mis-splicing can result in various human diseases by modifying or abrogating important physiological protein functions, a fine-tuned balance of AS is essential for human health. Accumulated data highlight the importance of alternatively spliced isoforms in various diseases, including neurodegenerative disorders, cancer, immune and infectious diseases, cardiovascular diseases, and metabolic conditions. However, basic understanding of disease mechanisms and development of clinical applications still require the integration and interpretation of physiological roles of AS. This review discusses the roles of AS in health and various diseases, while highlighting potential AS-targeting therapeutic applications.

BackgroundThe prevalence of metabolic syndrome has markedly increased worldwide. However, studies in the United States show that it has remained stable or slightly declined in recent years. Whether this applies to other countries is presently unclear.ObjectivesWe examined the trends in the prevalence of metabolic syndrome and its components in Korea.MethodsThe prevalence of metabolic syndrome and its components was estimated in adults aged >30 years from the Korean National Health Insurance Service data from 2009 to 2013. The revised National Cholesterol Education Program criteria were used to define metabolic syndrome.ResultsApproximately 10 million individuals were analyzed annually. The age-adjusted prevalence of metabolic syndrome increased from 28.84% to 30.52%, and the increasing trend was more prominent in men. Prevalence of hypertriglyceridemia, low HDL-cholesterol, and impaired fasting plasma glucose significantly increased. However, the prevalence of hypertension decreased in both genders. The prevalence of abdominal obesity decreased in women over 50 years-of-age but significantly increased in young women and men (<50 years).ConclusionsThe prevalence of metabolic syndrome is still increasing in Korea. Trends in each component of metabolic syndrome are disparate according to the gender, or age groups. Notably, abdominal obesity among young adults increased significantly; thus, interventional strategies should be implemented particularly for this age group.

BackgroundRepresentative data on the secular trends in cardiovascular disease (CVD) are limited in Asian populations with diabetes. We aimed to estimate the temporal trends in cardiovascular complications using Korean nationwide whole population-based claims data in subjects with and without diabetes.MethodsType 2 diabetes was defined as a current medication history of anti-diabetic drugs and the presence of International Classification of Diseases (ICD)-10 codes (E11–E14) as diagnosis. We compared the 8-year rates of six cardiovascular complications [i.e., ischemic heart disease, acute myocardial infarction (AMI), ischemic stroke, hemorrhagic stroke, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG)] in Korean adults aged 30 years and older using data from four consecutive nationwide databases (2006–2007, 2008–2009, 2010–2011, and 2012–2013) of Korean national health insurance service.ResultsA total of 1,645,348, 1,971,559, 2,291,247, and 2,562,612 subjects with type 2 diabetes were found in the year of 2006–2007, 2008–2009, 2010–2011, and 2012–2013, respectively. Age and gender standardized rates of the six predefined cardiovascular complications decreased in Korean adults with type 2 diabetes during the study period. The greatest relative reductions were observed for hospitalization due to AMI (−37.28%), followed by hospitalizations due to ischemic stroke (−36.98%). In the overall population without type 2 diabetes, the greatest relative reductions were observed for hospitalization for hemorrhagic stroke (−29.47%), followed by hospitalization due to ischemic stroke (−28.92%). Relative decreases in all six predefined cardiovascular complications were generally more profound in adults with diabetes than in those without diabetes, which led to significant decrease in the relative risks of all six cardiovascular complications in subjects with diabetes over the past 8 years. However, people with diabetes still had a two- to sixfold higher risk of hospitalization for major CVD events and interventions than people without diabetes.ConclusionsOur findings suggest a significant reduction in the rate of people affected by CVD within the diabetic population. However, as the number of people with diabetes rises, the absolute burden of CVD will still be high in Korea.Electronic supplementary materialThe online version of this article (doi:10.1186/s12933-016-0482-6) contains supplementary material, which is available to authorized users.

There was a high prevalence of peripheral neuropathy in patients with Type 2 diabetes in Korea and those patients were far more likely to have complications or co-morbidities. The proper management of diabetic peripheral neuropathy deserves attention from clinicians to ensure better management of diabetes in Korea.

Korea's National Healthcare Program, the National Health Insurance Service (NHIS), a government-affiliated agency under the Korean Ministry of Health and Welfare, covers the entire Korean population. The NHIS supervises all medical services in Korea and establishes a systematic National Health Information database (DB). A health information DB system including all of the claims, medications, death information, and health check-ups, both in the general population and in patients with various diseases, is not common worldwide. On June 9, 2014, the NHIS signed a memorandum of understanding with the Korean Diabetes Association (KDA) to provide limited open access to its DB. By October 31, 2017, seven papers had been published through this collaborative research project. These studies were conducted to investigate the past and current status of type 2 diabetes mellitus and its complications and management in Korea. This review is a brief summary of the collaborative projects between the KDA and the NHIS over the last 3 years. According to the analysis, the national health check-up DB or claim DB were used, and the age category or study period were differentially applied.