The Korean undiagnosed diseases program: lessons from a one-year pilot project.

Background: The Korean Undiagnosed Diseases Program (KUDP) was launched in January 2017 as a one-year pilot project to address the increasing global interest in patients with undiagnosed rare diseases. The purpose of this paper is to summarize the project results and emphasize the unmet research needs among patients with undiagnosed rare diseases in Korea.

Results: Patient enrollment, assessment, and diagnostic processes were determined by the KUDP clinical expert consortium.

Obesity associates with vasomotor symptoms in postmenopause but with physical symptoms in perimenopause: a cross-sectional study.

Background: Middle-aged women experience various menopausal symptoms during the menopause. These symptoms can affect their quality of life and health. Several epidemiological studies reported that obesity associates with menopausal symptoms.

The "Jolly Fat" Effect in Middle-Aged Korean Women.

Background: It has been hypothesized that depression and obesity are bi-directionally associated, and when overweight people appear to show a lower risk of depression, this supports the "Jolly Fat" hypothesis. The aim of this study was to examine the "Jolly Fat" hypothesis in middle-aged women in Korea, by different perceived stress levels.

Methods: We performed a cross-sectional study of 44 to 56 aged Korean women (n = 2201) who underwent a health check-up program at the healthcare centers of Kangbuk Samsung Hospital (Seoul and Suwon centers) in Korea.

The Korea Nurses' Health Study: A Prospective Cohort Study.

Background: The Korea Nurses' Health Study (KNHS) is a prospective cohort study of female nurses, focusing on the effects of occupational, environmental, and lifestyle risk factors on the health of Korean women.

Materials And Methods: Female registered nurses aged 20-45 years and living in the Republic of Korea were invited to join the study, which began in July 2013. They were asked to complete a web-based baseline survey.

The dietary monounsaturated to saturated fatty acid ratio modulates the genetic effects of GCKR on serum lipid levels in children.

Background: Glucokinase regulator (GCKR) plays important roles in the regulation of glucokinase (GK) activity and the metabolism of glucose and lipids. We investigated whether the association between GCKR genetic variants with serum lipids in Korean adults is replicated in children, and whether these genetic influences might be modulated by dietary monounsaturated fatty acid relative to saturated fatty acid (MUFA:SFA) ratio.

Methods: We genotyped 711 children for GCKR variants, used 7495 adults in KARE database, and analyzed anthropometric, biochemical, and dietary measurements.

Relation of Dietary Glycemic Index and Glycemic Load to Coronary Artery Calcium in Asymptomatic Korean Adults.

The relation between glycemic index, glycemic load, and subclinical coronary atherosclerosis is unknown. The aim of the study was to evaluate the associations between energy-adjusted glycemic index, glycemic load, and coronary artery calcium (CAC). This study was cross-sectional analysis of 28,429 asymptomatic Korean men and women (mean age 41.

Menopausal stages and non-alcoholic fatty liver disease in middle-aged women.

Objectives: There is no established evidence regarding the influence of the menopausal transition period on non-alcoholic fatty liver disease (NAFLD). The goal of this study was to examine the association between menopausal stages and the prevalence of NAFLD in middle-aged Korean women.

Methods: This study was a cross-sectional analysis of 1559 women aged 44-56 years, who underwent a comprehensive health screening examination in the Kangbuk Samsung Hospital Total Healthcare Centers during 2012 and 2013.

Prevalence and severity of menopause symptoms and associated factors across menopause status in Korean women.

Objective: The present study investigated the prevalence and severity of menopause symptoms experienced by Korean women aged 44 to 56 years and their associated factors.

Methods: A cross-sectional study was performed on 2,201 women aged 44 to 56 years in health checkup centers between November 2012 and March 2013. The 29-item Menopause-Specific Quality of Life Questionnaire was used to assess vasomotor, psychosocial, physical, and sexual symptoms related to menopause.

Habitual coffee intake, genetic polymorphisms, and type 2 diabetes.

Background: The association between coffee intake and type 2 diabetes may be modulated by common genetic variation.

Objective: The purpose of this study was to examine the association between habitual coffee intake and the risk of type 2 diabetes and to determine whether this association varied by genetic polymorphisms related to type 2 diabetes in Korean adults.

Design And Methods: A population-based cohort study over a follow-up of 4 years was conducted.

Menopausal stages and serum lipid and lipoprotein abnormalities in middle-aged women.

Objectives: Whether menopausal stage is associated with abnormalities in serum lipid and lipoprotein profiles remains unclear; studies have been conducted mostly in Western populations. This study aimed to examine the prevalence of lipid and lipoprotein abnormalities by recently updated menopausal stages in middle-aged women.

Study Design: This study was cross-sectional analysis of 1553 women aged 44-56 years, who underwent a comprehensive health screening examination in the Kangbuk Samsung Hospital Total Healthcare Centers, Korea, during 2012-2013.

Plasma isoflavone concentration is associated with decreased risk of type 2 diabetes in Korean women but not men: results from the Korean Genome and Epidemiology Study.

Aims/hypothesis: To examine the association between soybean products and risk of type 2 diabetes, we measured four isoflavone biological markers--genistein, daidzein, glycitein and equol--in a nested case-control study.

Methods: The study population was composed of 693 cases (316 women and 377 men) and 698 matched controls (317 women and 381 men) within the Korean Genome and Epidemiology Study. The concentrations of isoflavone biomarkers were measured using HPLC-MS/MS on plasma samples that were collected at baseline.

Intake levels of dietary polyunsaturated fatty acids modify the association between the genetic variation in PCSK5 and HDL cholesterol.

Background: A low serum level of high-density lipoprotein cholesterol (HDL-C) is a risk factor for cardiovascular disease. Proprotein convertase subtilisin/kexin type 5 (PCSK5) modulates HDL-C metabolism through the inactivation of endothelial lipase activity.

Methods: Therefore, we analysed the effects of PCSK5 on HDL-C and investigated the association between genetic variation in PCSK5 and dietary polyunsaturated fatty acids (PUFAs) intakes in Korean adults and children.

Association between physical activity and menopausal symptoms in perimenopausal women.

Background: Physical activity may be an effective way of preventing or attenuating menopause-related symptoms, and it has been shown to improve quality of life in menopausal women. However, there have been some inconsistencies regarding between exercise and menopausal symptoms, and study investigating this association has been scarce in Korea. In this study, the association between physical activity and menopausal symptoms in perimenopausal women in Korea was assessed.

Dietary patterns and osteoporosis risk in postmenopausal korean women.

Objectives: The prevalence of osteoporosis and related fractures has increased rapidly in Korean women. Proper nutrition intake is associated with the prevention of osteoporosis. We analyzed the association between dietary patterns and the risk of osteoporosis during a 4-year follow-up in postmenopausal Korean women.

Dietary intake and breast cancer among carriers and noncarriers of BRCA mutations in the Korean Hereditary Breast Cancer Study.

Background: Soy intake is associated with a lower risk of breast cancer. However, it is unclear whether the same reduction in risk associated with high soy intake is also applicable to familial or genetic breast cancer.

Objective: The aim of this study was to assess the dietary factors among carriers and noncarriers of BRCA mutations in the Korean Hereditary Breast Cancer Study (KOHBRA).

Rice-eating pattern and the risk of metabolic syndrome especially waist circumference in Korean Genome and Epidemiology Study (KoGES).

Background: Metabolic syndrome poses a serious health threat in Asian countries. Rice is a staple food in Korea, and carbohydrate intake is associated with the risk of MetS. We hypothesized that various rice-eating patterns in a carbohydrate-based diet would have different effects on the risk of MetS.

Epidemiological profiles between equol producers and nonproducers: a genomewide association study of the equol-producing phenotype.

Equol is a daidzein (a phytoestrogen isoflavone) metabolite of gut bacteria, and the ability to produce equol varies between individuals and reduces the risks of several diseases. We tested the effects of equol production on health in Koreans and identified the genetic factors that determine the equol-producing phenotype. In 1391 subjects, the equol-producing phenotype was determined, based on measurements of serum equol concentrations.

Recapitulation of the association of the Val66Met polymorphism of BDNF gene with BMI in Koreans.

Recent evidence suggests that brain-derived neurotrophic factor (BDNF) regulates food intake and the control of body weight. A common polymorphism in human BDNF, Val66Met (single-nucleotide polymorphism database (dbSNP) no. rs6265), impairs intracellular trafficking, resulting in the reduced secretion of BDNF.

Plasma calcium and risk of hypertension: propensity score analysis using data from the korean genome and epidemiology study.

Objective: To investigate associations between plasma calcium and future incidence of hypertension in a healthy population.

Methods: We used prospective data from Ansung and Ansan cohorts (n = 10,038) of the Korean Genome and Epidemiology Study. Data from baseline (2001-02) to the fourth study (2007-08) were used.

A prospective study investigating the association between environmental tobacco smoke exposure and the incidence of type 2 diabetes in never smokers.

Purpose: We studied a cohort of individuals to assess whether intensity of environmental tobacco smoke (ETS) exposure is associated with the incidence of type 2 diabetes.

Methods: Study subjects were selected from an ongoing population-based cohort of Korea Genome and Epidemiology Study. Participants of the baseline study 10,038 persons within the age range of 40 to 69 years old.

Effects of common FTO gene variants associated with BMI on dietary intake and physical activity in Koreans.

Background: Associations with FTO (fat mass and obesity associated) gene variants and BMI have been reported in western adult populations. To widen the ethnic and age coverage of the FTO studies, we investigated the effects of FTO gene variants on being overweight and related phenotypes in Korean children and adult with a consideration of lifestyle factors.

Methods: We genotyped 711 children for 2 FTO SNPs (rs9939973 and rs9939609), analyzed lifestyle factors, and investigated the potential involvement of FTO variants in being overweight comparing with 8842 adults in the KSNP database.

Relative validities of 3-day food records and the food frequency questionnaire.

The food frequency questionnaire (FFQ) has been used as an important dietary assessment tool in epidemiologic studies, but the usefulness of the FFQ has been debated in recent years. This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ. A total of 124 subjects finished 3-day food records (FRs) during each of the four seasons, as well as the FFQ from December 2002 to May 2004.

Dietary pattern classifications with nutrient intake and health-risk factors in Korean men.

Objective: This study was performed to identify dietary patterns in Korean men and to determine the associations among dietary patterns, nutrient intake, and health-risk factors.

Methods: Using baseline data from the Korean Health and Genome Study, dietary patterns were identified using factor analysis of data from a validated food-frequency questionnaire, and associations between these dietary patterns and health-risk factors were analyzed.

Results: Three dietary patterns were identified: 1) the "animal-food" pattern (greater intake of meats, fish, and dairy products), 2) the "rice-vegetable" pattern (greater intake of rice, tofu, kimchi, soybean paste, vegetables, and seaweed), and 3) the "noodle-bread" pattern (greater intake of instant noodles, Chinese noodles, and bread).

A large-scale genome-wide association study of Asian populations uncovers genetic factors influencing eight quantitative traits.

To identify genetic factors influencing quantitative traits of biomedical importance, we conducted a genome-wide association study in 8,842 samples from population-based cohorts recruited in Korea. For height and body mass index, most variants detected overlapped those reported in European samples. For the other traits examined, replication of promising GWAS signals in 7,861 independent Korean samples identified six previously unknown loci.

[Seasonal variation of food intake in food frequency questionnaire among workers in a nuclear power plant].

Objectives: This study was conducted to investigate the systematic error, such as seasonal change or inadequate food items, in a food frequency questionnaire administered to workers in a Nuclear Power Plant, Korea.

Methods: We performed three repeat-tests with 28 subjects on May 13, July 8 and Dec 16, 1992. Our food frequency questionnaire (FFQ) comprised 84 foods organized into 7 food-groups, and was composed of the items of usual intake frequency (8 categories) and the amount per intake (3 or 4 categories) over the previous year.