Genome-Wide Association Study on Longitudinal Change in Fasting Plasma Glucose in Korean Population

Background@#Genome-wide association studies (GWAS) on type 2 diabetes mellitus (T2DM) have identified more than 400 distinct genetic loci associated with diabetes and nearly 120 loci for fasting plasma glucose (FPG) and fasting insulin level to date. However, genetic risk factors for the longitudinal deterioration of FPG have not been thoroughly evaluated. We aimed to identify genetic variants associated with longitudinal change of FPG over time. @*Methods@#We used two prospective cohorts in Korean population, which included a total of 10,528 individuals without T2DM. GWAS of repeated measure of FPG using linear mixed model was performed to investigate the interaction of genetic variants and time, and meta-analysis was conducted. Genome-wide complex trait analysis was used for heritability calculation. In addition, expression quantitative trait loci (eQTL) analysis was performed using the Genotype-Tissue Expression project. @*Results@#A small portion (4%) of the genome-wide single nucleotide polymorphism (SNP) interaction with time explained the total phenotypic variance of longitudinal change in FPG. A total of four known genetic variants of FPG were associated with repeated measure of FPG levels. One SNP (rs11187850) showed a genome-wide significant association for genetic interaction with time. The variant is an eQTL for NOC3 like DNA replication regulator (NOC3L) gene in pancreas and adipose tissue. Furthermore, NOC3L is also differentially expressed in pancreatic β-cells between subjects with or without T2DM. However, this variant was not associated with increased risk of T2DM nor elevated FPG level. @*Conclusion@#We identified rs11187850, which is an eQTL of NOC3L, to be associated with longitudinal change of FPG in Korean population.

Triglyceride-Glucose Index Predicts Future Atherosclerotic Cardiovascular Diseases: A 16-Year Follow-up in a Prospective, Community-Dwelling Cohort Study

Background@#While the triglyceride-glucose (TyG) index is a measure of insulin resistance, its association with cardiovascular disease (CVD) has not been well elucidated. We evaluated the TyG index for prediction of CVDs in a prospective large communitybased cohort. @*Methods@#Individuals 40 to 70 years old were prospectively followed for a median 15.6 years. The TyG index was calculated as the Ln [fasting triglycerides (mg/dL)×fasting glucose (mg/dL)/2]. CVDs included any acute myocardial infarction, coronary artery disease or cerebrovascular disease. We used a Cox proportional hazards model to estimate CVD risks according to quartiles of the TyG index and plotted the receiver operating characteristics curve for the incident CVD. @*Results@#Among 8,511 subjects (age 51.9±8.8 years; 47.5% males), 931 (10.9%) had incident CVDs during the follow-up. After adjustment for age, sex, body mass index, diabetes mellitus, hypertension, total cholesterol, smoking, alcohol, exercise, and C-reactive protein, subjects in the highest TyG quartile had 36% increased risk of incident CVD compared with the lowest TyG quartile (hazard ratio, 1.36; 95% confidence interval, 1.10 to 1.68). Carotid plaque, assessed by ultrasonography was more frequent in subjects in the higher quartile of TyG index (P for trend=0.049 in men and P for trend <0.001 in women). The TyG index had a higher predictive power for CVDs than the homeostasis model assessment of insulin resistance (HOMA-IR) (area under the curve, 0.578 for TyG and 0.543 for HOMA-IR). Adding TyG index on diabetes or hypertension alone gave sounder predictability for CVDs. @*Conclusion@#The TyG index is independently associated with future CVDs in 16 years of follow-up in large, prospective Korean cohort.

Metabolic Dysfunction-Associated Fatty Liver Disease Predicts Long-term Mortality and Cardiovascular Disease

Background/aims@#We investigated the effect of metabolic dysfunction-associated fatty liver disease (MAFLD) on future mortality and cardiovascular disease (CVD) using a prospective community-based cohort study. @*Methods@#Individuals from two community-based cohorts who were 40 to 70 years old were prospectively followed for 16 years. MAFLD was defined as a high fatty liver index (FLI ≥60) plus one of the following conditions: overweight/obesity (body mass index ≥23 kg/m2), type 2 diabetes mellitus, or ≥2 metabolic risk abnormalities. Nonalcoholic fatty liver disease (NAFLD) was defined as FLI ≥60 without any secondary cause of hepatic steatosis. @*Results@#Among 8,919 subjects (age 52.2±8.9 years, 47.7% of males), 1,509 (16.9%) had MAFLD. During the median follow-up of 15.7 years, MAFLD independently predicted overall mortality after adjustment for confounders (hazard ratio [HR], 1.33; 95% confidence interval [CI], 1.05 to 1.69) but NAFLD did not (HR, 1.20; 95% CI, 0.94 to 1.53). MAFLD also predicted CVD after adjustment for age, sex, and body mass index (HR, 1.35; 95% CI, 1.13 to 1.62), which lost its statistical significance by further adjustments. Stratified analysis indicated that metabolic dysfunction contributed to mortality (HR, 1.51; 95% CI, 1.21 to 1.89) and CVD (HR, 1.27; 95% CI, 1.02 to 1.59). Among metabolic dysfunctions used for defining MAFLD, type 2 diabetes mellitus in MAFLD increased the risk of both mortality (HR, 2.07; 95% CI, 1.52 to 2.81) and CVD (HR, 1.42; 95% CI, 1.09 to 1.85). @*Conclusions@#MAFLD independently increased overall mortality. Heterogeneity in mortality and CVD risk of subjects with MAFLD may be determined by the accompanying metabolic dysfunctions.

Analysis of Asian Mitochondrial DNA Haplogroups Associated With the Progression of Knee Osteoarthritis in Koreans

Objective@#. We investigated Asian mitochondrial DNA (mtDNA) haplogroups associated with knee osteoarthritis (OA) progression in a prospective community-based cohort comprised of Koreans. @*Methods@#. Epidemiologic data and Kellgren-Lawrence (K/L) scores of knee radiographs were obtained from the second (2005∼2006) and sixth (2013∼2014) follow-up, and patient DNA was analyzed. The mtDNA haplogroup frequencies (M, G, D, D4, D5, M7, M8, M9, M10, N, A, N9, R, F, and B) were compared between the progression (K/L score change on either knee ≥2 or arthroplasty) and non-progression (K/L score change on both knee ≤1) groups at the sixth follow-up. Multiple logistic regression was performed to determine relative risk (RRs) of mtDNA haplogroups for OA. @*Results@#. In total, 1,115 participants were included, 405 of whom had early OA (higher K/L score on both knees of 1 or 2). Among them, 143 and 166 patients were classified in non-progression and progression groups, respectively, at the sixth follow-up. The most frequent haplogroups, B and D4, in Koreans also showed a high frequency in our study. There were no significantly different haplogroups between the non-progression and progression groups. However, the frequency of haplogroup D4 was likely higher in the non-progression group than in the progression group, although not significantly (13.3% vs. 7.2%, RR=0.51, p=0.081 in the unadjusted model and RR=0.56, p=0.149 in the adjusted model). @*Conclusion@#. No significant haplogroups are related to OA progression. Large-scaled studies are needed to reveal the association between mtDNA haplogroups and OA.

Low Predictive Value of FRAX Adjusted by Trabecular Bone Score for Osteoporotic Fractures in Korean Women: A Community-Based Cohort Study

Background@#The value of the Fracture Risk Assessment Tool (FRAX) and the trabecular bone score (TBS) for assessing osteoporotic fracture risk has not been fully elucidated in Koreans. We conducted this study to clarify the predictive value of FRAX adjusted by TBS for osteoporotic fractures in Korean women. @*Methods@#After screening 7,192 eligible subjects from the Ansung cohort, 1,165 women aged 45 to 76 years with available bone mineral density (BMD) and TBS data were enrolled in this study. We assessed their clinical risk factors for osteoporotic fractures and evaluated the predictive value of FRAX with or without BMD and TBS. @*Results@#During the mean follow-up period of 7.5 years, 99 (8.5%) women suffered major osteoporotic fractures (MOFs) and 28 (2.4%) experienced hip fractures. FRAX without BMD, BMD-adjusted FRAX, and TBS-adjusted FRAX were significantly associated with the risk of MOFs (hazard ratio [HR] per percent increase, 1.08; 95% confidence interval [CI], 1.03 to 1.14; HR, 1.09; 95% CI, 1.03 to 1.15; and HR, 1.07; 95% CI, 1.02 to 1.13, respectively). However, BMD-adjusted FRAX and TBS-adjusted FRAX did not predict MOFs better than FRAX without BMD based on the Harrell’s C statistic. FRAX probabilities showed limited value for predicting hip fractures. The cut-off values of FRAX without BMD, FRAX with BMD, and FRAX with BMD adjusted by TBS for predicting MOFs were 7.2%, 5.0%, and 6.7%, respectively. @*Conclusion@#FRAX with BMD and TBS adjustment did not show better predictive value for osteoporotic fractures in this study than FRAX without adjustment. Moreover, the cut-off values of FRAX probabilities for treatment might be lower in Korean women than in other countries.

Association of Body Mass Index with the Risk of Incident Type 2 Diabetes, Cardiovascular Disease, and All-Cause Mortality: A Community-Based Prospective Study

Background@#Type 2 diabetes and cardiovascular disease (CVD) are the most important sequelae of obesity and the leading cause of death. We evaluated the association between body mass index (BMI) and the risk of incident type 2 diabetes, CVD, and all-cause mortality in a prospective study of a Korean population. @*Methods@#The shapes of the associations were modeled by restricted cubic splines regression analysis. After categorizing all subjects (n=8,900) into octiles based on their BMI levels, we estimated the hazard ratio (HR) for the association of categorized BMI levels with the risk of incident CVD and type 2 diabetes using a Cox’s proportional hazard analysis. @*Results@#The mean age of participants was 52 years and 48% were men. Of the subjects at baseline, 39.0% of men and 45.6% of women were classified as obese (BMI ≥25 kg/m2). Over a mean follow-up of 8.1 years, CVD events occurred in 509 participants; 436 died; and 1,258 subjects developed type 2 diabetes. The increased risk of incident diabetes began to be significant at BMI 23 to 24 kg/m2 in both sexes (HR, 1.8). For CVD events, the risk began to increase significantly at BMI 26 to 28 kg/m2 (HR, 1.6). We found a reverse J-shaped relationship between BMI and all-cause mortality, with an increased risk among individuals with BMI values in lower range (BMI <21 kg/m2). @*Conclusion@#These results suggest that the BMI cut-off points for observed risk were varied depending on the diseases and that the BMI classification of obesity need to be revised to reflect differential risk of obesity-related diseases.

Identification of Novel Genetic Variants Related to Trabecular Bone Score in Community-Dwelling Older Adults

Background@#As the genetic variants of trabecular bone microarchitecture are not well-understood, we performed a genome-wide association study to identify genetic determinants of bone microarchitecture analyzed by trabecular bone score (TBS). @*Methods@#TBS-associated genes were discovered in the Ansung cohort (discovery cohort), a community-based rural cohort in Korea, and then validated in the Gene-Environment Interaction and Phenotype (GENIE) cohort (validation cohort), consisting of subjects who underwent health check-up programs. In the discovery cohort, 2,451 participants were investigated for 1.42 million genotyped and imputed markers. @*Results@#In the validation cohort, identified as significant variants were evaluated in 2,733 participants. An intronic variant in iroquois homeobox 3 (IRX3), rs1815994, was significantly associated with TBS in men (P=3.74E-05 in the discovery cohort, P=0.027 in the validation cohort). Another intronic variant in mitogen-activated protein kinase kinase 5 (MAP2K5), rs11630730, was significantly associated with TBS in women (P=3.05E-09 in the discovery cohort, P=0.041 in the validation cohort). Men with the rs1815994 variant and women with the rs11630730 variant had lower TBS and lumbar spine bone mineral density. The detrimental effects of the rs1815994 variant in men and rs11630730 variant in women were also identified in association analysis (β=–0.0281, β=–0.0465, respectively). @*Conclusion@#In this study, the rs1815994 near IRX3 in men and rs11630730 near MAP2K5 in women were associated with deterioration of the bone microarchitecture. It is the first study to determine the association of genetic variants with TBS. Further studies are needed to confirm our findings and identify additional variants contributing to the trabecular bone microarchitecture.

Identification of Novel Genetic Variants Related to Trabecular Bone Score in Community-Dwelling Older Adults

Background@#As the genetic variants of trabecular bone microarchitecture are not well-understood, we performed a genome-wide association study to identify genetic determinants of bone microarchitecture analyzed by trabecular bone score (TBS). @*Methods@#TBS-associated genes were discovered in the Ansung cohort (discovery cohort), a community-based rural cohort in Korea, and then validated in the Gene-Environment Interaction and Phenotype (GENIE) cohort (validation cohort), consisting of subjects who underwent health check-up programs. In the discovery cohort, 2,451 participants were investigated for 1.42 million genotyped and imputed markers. @*Results@#In the validation cohort, identified as significant variants were evaluated in 2,733 participants. An intronic variant in iroquois homeobox 3 (IRX3), rs1815994, was significantly associated with TBS in men (P=3.74E-05 in the discovery cohort, P=0.027 in the validation cohort). Another intronic variant in mitogen-activated protein kinase kinase 5 (MAP2K5), rs11630730, was significantly associated with TBS in women (P=3.05E-09 in the discovery cohort, P=0.041 in the validation cohort). Men with the rs1815994 variant and women with the rs11630730 variant had lower TBS and lumbar spine bone mineral density. The detrimental effects of the rs1815994 variant in men and rs11630730 variant in women were also identified in association analysis (β=–0.0281, β=–0.0465, respectively). @*Conclusion@#In this study, the rs1815994 near IRX3 in men and rs11630730 near MAP2K5 in women were associated with deterioration of the bone microarchitecture. It is the first study to determine the association of genetic variants with TBS. Further studies are needed to confirm our findings and identify additional variants contributing to the trabecular bone microarchitecture.

Oral Glucose Tolerance Testing Allows Better Prediction of Diabetes in Women with a History of Gestational Diabetes Mellitus

BACKGROUND: We aimed to identify the postpartum metabolic factors that were associated with the development of diabetes in women with a history of gestational diabetes mellitus (GDM). In addition, we examined the role of the oral glucose tolerance test (OGTT) in the prediction of future diabetes. METHODS: We conducted a prospective study of 179 subjects who previously had GDM but did not have diabetes at 2 months postpartum. The initial postpartum examination including a 75-g OGTT and the frequently sampled intravenous glucose tolerance test (FSIVGTT) was performed 12 months after delivery, and annual follow-up visits were made thereafter. RESULTS: The insulinogenic index (IGI30) obtained from the OGTT was significantly correlated with the acute insulin response to glucose (AIRg) obtained from the FSIVGTT. The disposition indices obtained from the OGTT and FSIVGTT were also significantly correlated. Women who progressed to diabetes had a lower insulin secretory capacity including IGI30, AIRg, and disposition indices obtained from the FSIVGTT and OGTT compared with those who did not. However, the insulin sensitivity indices obtained from the OGTT and FSIVGTT did not differ between the two groups. Multivariate logistic regression analysis showed that the 2-hour glucose and disposition index obtained from the FSIVGTT were significant postpartum metabolic risk factors for the development of diabetes. CONCLUSION: We identified a crucial role of β-cell dysfunction in the development of diabetes in Korean women with previous GDM. The 2-hour glucose result from the OGTT is an independent predictor of future diabetes. Therefore, the OGTT is crucial for better prediction of future diabetes in Korean women with previous GDM.

Carbohydrate Composition Associated with the 2-Year Incidence of Metabolic Syndrome in Korean Adults

The aim of this study was to investigate the association between macronutrient composition and metabolic syndrome (MetS) incidence in Korean adults. Data were obtained from a cohort of 10,030 members aged 40 to 69 years who were enrolled from the 2 cities (Ansung and Ansan) between 2001 and 2002 to participate in the Korean Genome Epidemiology Study. Of these members, 5,565 participants, who were free of MetS and reported no diagnosis of cardiovascular disease at baseline, were included in this study. MetS was defined using the criteria of the National Cholesterol Education Program-Adult Treatment Panel III and Asia-Pacific criteria for waist circumference. MetS incidence rate were identified during a 2-year follow-up period. Baseline dietary information was obtained using a semi-quantitative food frequency questionnaire. Multivariate logistic regression analysis was used to evaluate the association between the quartiles of percentages of total calorie from macronutrients consumed and MetS incidence. In analyses, baseline information, including age, sex, body mass index, income status, educational status, smoking status, alcohol drinking status, and physical activity level was considered as confounding variables. Participants with the second quartile of the percentages of carbohydrate calorie (67%–70%) had a 23% reduced odds ratio (95% confidence interval, 0.61–0.97) for MetS incidence compared with those with the fourth quartile after adjusting for confounding variables. The findings suggest that middle aged or elderly Korean adults who consume approximately 67%–70% of calorie from carbohydrate have a reduced risk of MetS.

Prevalence and Risk Factors for Lumbar Spondylosis and Its Association with Low Back Pain among Rural Korean Residents

OBJECTIVE: The purpose of this study was to investigate the prevalence of and the relevant risk factors for lumbar spondylosis (LS) among middle-aged and elderly rural Korean residents and to explore the association between radiographic LS and lower back pain (LBP) in relation to age and gender. METHODS: This community-based, cross-sectional study evaluated 1512 subjects with available radiograph. The prevalence of LBP was obtained using a questionnaire and disability resulting from LBP was measured using a validated Korean version of the Oswestry disability index (ODI). In lumbar spine radiographs, vertebral levels from L1/2 to L4/5 were evaluated for the presence of osteophytes and joint-space narrowing (JSN), and Kellgren-Lawrence (KL) grading was applied. RESULTS: Of 4261 subjects aged 40–79 years, data from 1512 subjects were included. The prevalence of radiographic LS indicated by grade ≥2 osteophytes and JSN were 53.9 and 15.8%, respectively. Seventy-three percent of subjects had KL grade ≥2 spondylosis and LBP was present in 36.5% of subjects. Although LS was more common among males, the prevalence of LBP was higher among females. Age, male gender and history of hand or knee arthritis were risk factors for LS. LS was significantly associated with LBP mostly among females over 60 years old and correlated with the ODI after adjusting for age and gender. CONCLUSION: Our study among rural Korean residents revealed a high prevalence of LS and LBP. The association between LS and LBP was observed mostly among females and LS was significantly correlated with the severity of back pain.

Glucose-Dependent Insulinotropic Peptide Level Is Associated with the Development of Type 2 Diabetes Mellitus

BACKGROUND: Incretin hormone levels as a predictor of type 2 diabetes mellitus have not been fully investigated. Therefore, we measured incretin hormone levels to examine the relationship between circulating incretin hormones, diabetes, and future diabetes development in this study. METHODS: A nested case-control study was conducted in a Korean cohort. The study included the following two groups: the control group (n=149), the incident diabetes group (n=65). Fasting total glucagon-like peptide-1 (GLP-1) and total glucose-dependent insulinotropic peptide (GIP) levels were measured and compared between these groups. RESULTS: Fasting total GIP levels were higher in the incident diabetes group than in the control group (32.64±22.68 pmol/L vs. 25.54±18.37 pmol/L, P=0.034). There was no statistically significant difference in fasting total GLP-1 levels between groups (1.14±1.43 pmol/L vs. 1.39±2.13 pmol/L, P=0.199). In multivariate analysis, fasting total GIP levels were associated with an increased risk of diabetes (odds ratio, 1.005; P=0.012) independent of other risk factors. CONCLUSION: Fasting total GIP levels may be a risk factor for the development of type 2 diabetes mellitus. This association persisted even after adjusting for other metabolic parameters such as elevated fasting glucose, hemoglobin A1c, and obesity in the pre-diabetic period.

Sex-specific differences in the association of a common aldehyde dehydrogenase 2 gene polymorphism and alcohol consumption with stroke risk in a Korean population: a prospective cohort study

BACKGROUND/OBJECTIVES: It is well-known that alcohol consumption is associated with stroke risk as well as with aldehyde dehydrogenase 2 gene (ALDH2) polymorphisms. However, it is unclear whether ALDH2 polymorphisms are associated with stroke risk independent of alcohol consumption and whether such association is modified by sex. We evaluated sex-specific associations of a common ALDH2 polymorphism and alcohol consumption with stroke risk in a Korean population. SUBJECTS/METHODS: We conducted a prospective cohort study involving 8,465 men and women, aged 40-69 years and free of stroke between June, 2001 and January, 2003, and followed for the development of stroke. We identified new cases of stroke, which were self-reported or ascertained from vital registration data. Based on genome-wide association data, we selected a single-nucleotide polymorphism (rs2074356), which shows high linkage disequilibrium with the functional polymorphism of ALDH2. We conducted Cox proportional hazards regression analysis considering potential risk factors collected from a baseline questionnaire. RESULTS: Over the median follow-up of 8 years, 121 cases of stroke were identified. Carrying the wild-type allele of the ALDH2 polymorphism increased stroke risk among men. The multivariate hazard ratio [95% confidence interval] of stroke was 2.02 [1.03-3.99] for the wild-type allele compared with the mutant alleles, but the association was attenuated after controlling for alcohol consumption. Combinations of the wild-type allele and other risk factors of stroke, such as old age, diabetes mellitus, and habitual snoring, synergistically increased the risk among men. Among women, however, the ALDH2 polymorphism was not associated with stroke risk. CONCLUSIONS: The prospective cohort study showed a significant association between a common ALDH2 polymorphism and stroke risk in Korean men, but not in Korean women, and also demonstrated that men with genetic disadvantages gain more risk when having risk factors of stroke. Thus, these men may need to make more concerted efforts to control modifiable risk factors of stroke.

Sex Factors in the Metabolic Syndrome as a Predictor of Cardiovascular Disease

BACKGROUND: Metabolic syndrome (MetS) is a condition characterized by a cluster of metabolic disorders and is associated with increased risk of cardiovascular disease (CVD). This study analyzed data from the Korean Health and Genome Study to examine the impact of MetS on CVD. METHODS: A total of 8,898 subjects (4,241 males and 4,657 females), 40 to 69 years of age, were enrolled and evaluated for the development of new onset CVD from 2001 to 2012 (median 8.1 years of follow-up). RESULTS: The prevalence of MetS at baseline was 22.0% (932/4,241) and 29.7% (1,383/4,657) in males and females, respectively. MetS was associated with increased risk of coronary heart disease (CHD; hazard ratio [HR], 1.818; 95% confidence interval [CI], 1.312 to 2.520 in males; HR, 1.789; 95% CI, 1.332 to 2.404 in females) and CVD (HR, 1.689; 95% CI, 1.295 to 2.204 in males; HR, 1.686; 95% CI, 1.007 to 2.192 in females). Specifically, MetS was associated with risk of future stroke in females only (HR, 1.486; 95% CI, 1.007 to 2.192). Among MetS components, abdominal obesity and hypertension were independent predictors of both CHD and CVD. In addition, a higher number of MetS components correlated with higher CVD risk. CONCLUSION: MetS is a significant risk factor for the development of CVD although its impact varies between sexes.

Sarcopenia and Obesity: Gender-Different Relationship with Functional Limitation in Older Persons

Age-related body composition changes such as sarcopenia and obesity affect functional decline in the elderly. We investigated the relationship between body composition parameters and functional limitation in older Korean adults. We enrolled 242 men and 231 women aged > or = 65 yr from the Korean elderly cohort. We used appendicular skeletal muscle mass (ASM) divided by height2 (ASM/Ht2) and ASM divided by weight (ASM/Wt). The isokinetic strength of knee extensor muscles were measured using an isokinetic device. Functional limitations were assessed using the Short Physical Performance Battery (SPPB) score less than nine. Men within the bottom tertile of ASM/Ht2 confer an increased risk for functional limitation compared with those within the top tertile (OR, 6.24; 95% CI, 1.78-22.0). However, in women, subjects within the lowest ASM/Wt tertile had a higher risk compared with those within the highest tertile instead of ASM/Ht2 (OR, 7.60; 95% CI, 2.25-25.7). Leg muscle strength remained the strong measure even after controlling for muscle mass only in women. Only large waist circumference was positively associated with functional limitation only in women. We might consider a different muscle index to assess functional limitation according to the gender.

Erratum: Correction of Figure. Sarcopenia and Obesity: Gender-Different Relationship with Functional Limitation in Older Persons

The legends of Fig. 1 were marked incorrectly.

Prevalence and Risk Factor of Neck Pain in Elderly Korean Community Residents

Neck pain is a common musculoskeletal condition, which causes substantial medical cost. In Korea, prevalence of neck pain in community based population, especially in elderly subjects, has scarcely been reported. We evaluated the prevalence, the severity and the risk factors of neck pain in elderly Korean community residents. Data for neck pain were collected for 1,655 subjects from a rural farming community. The point, 6-months and cumulative lifetime prevalence of neck pain was obtained in addition to the measurement of the severity of neck pain. The mean age of the study subjects was 61 yr and 57% were females. The lifetime prevalence of neck pain was 20.8% with women having a higher prevalence. The prevalence did not increase with age, and the majority of individuals had low-intensity/low-disability pain. Subjects with neck pain had a significantly worse SF-12 score in all domains except for mental health. The prevalence of neck pain was significantly associated with female gender, obesity and smoking. This is the first large-scale Korean study estimating the prevalence of neck pain in elderly population. Although the majority of individuals had low-intensity/low-disability pain, subjects with neck pain had a significantly worse SF-12 score indicating that neck pain has significant health impact.

Interaction Effects of Lipoprotein Lipase Polymorphisms with Lifestyle on Lipid Levels in a Korean Population: A Cross-sectional Study

Lipoprotein lipase (LPL) plays an essential role in the regulation of high-density lipoprotein cholesterol (HDLC) and triglyceride levels, which have been closely associated with cardiovascular diseases. Genetic studies in European have shown that LPL single-nucleotide polymorphisms (SNPs) are strongly associated with lipid levels. However, studies about the influence of interactions between LPL SNPs and lifestyle factors have not been sufficiently performed. Here, we examine if LPL polymorphisms, as well as their interaction with lifestyle factors, influence lipid concentrations in a Korean population. A two-stage association study was performed using genotype data for SNPs on the LPL gene, including the 3' flanking region from 7,536 (stage 1) and 3,703 (stage 2) individuals. The association study showed that 15 SNPs and 4 haplotypes were strongly associated with HDLC (lowest p = 2.86 x 10(-22)) and triglyceride levels (lowest p = 3.0 x 10(-15)). Interactions between LPL polymorphisms and lifestyle factors (lowest p = 9.6 x 10(-4)) were also observed on lipid concentrations. These findings suggest that there are interaction effects of LPL polymorphisms with lifestyle variables, including energy intake, fat intake, smoking, and alcohol consumption, as well as effects of LPL polymorphisms themselves, on lipid concentrations in a Korean population.

Interaction Effects of Lipoprotein Lipase Polymorphisms with Lifestyle on Lipid Levels in a Korean Population: A Cross-sectional Study

Lipoprotein lipase (LPL) plays an essential role in the regulation of high-density lipoprotein cholesterol (HDLC) and triglyceride levels, which have been closely associated with cardiovascular diseases. Genetic studies in European have shown that LPL single-nucleotide polymorphisms (SNPs) are strongly associated with lipid levels. However, studies about the influence of interactions between LPL SNPs and lifestyle factors have not been sufficiently performed. Here, we examine if LPL polymorphisms, as well as their interaction with lifestyle factors, influence lipid concentrations in a Korean population. A two-stage association study was performed using genotype data for SNPs on the LPL gene, including the 3' flanking region from 7,536 (stage 1) and 3,703 (stage 2) individuals. The association study showed that 15 SNPs and 4 haplotypes were strongly associated with HDLC (lowest p = 2.86 x 10(-22)) and triglyceride levels (lowest p = 3.0 x 10(-15)). Interactions between LPL polymorphisms and lifestyle factors (lowest p = 9.6 x 10(-4)) were also observed on lipid concentrations. These findings suggest that there are interaction effects of LPL polymorphisms with lifestyle variables, including energy intake, fat intake, smoking, and alcohol consumption, as well as effects of LPL polymorphisms themselves, on lipid concentrations in a Korean population.

The Epidemiology of Diabetes in Korea: From the Economics to Genetics / 당뇨병

To determine the factors responsible for the dramatic increase in the prevalence of diabetes in Korea. A computerized literature survey was conducted to evaluate the risk factors for Type 2 diabetes mellitus (T2DM) in Korea, including genome-wide association studies. National Statistics gross national income data was integrated with the reported prevalence of diabetes to evaluate the relationship between diabetes and the economic growth. The strength of the association was evaluated using measures of effect size, such as odds ratio and relative risks. The putative risk factors identified in Korean studies are very similar to the risk factors identified from the other countries, including genetic background. Genome-wide association studies reported relative risks of 1.5 or less, indicating that no single gene is associated with the risk of T2DM. The scientific evidence suggests that the dramatic increase in the incidence and prevalence of T2DM in Korea is related to the economic development of Korea, which has a direct influence on health policy, as well as an individual's health behaviors. We expect to observe the current diabetes incidence rates until the key risk factors are present for long enough in our society, at which point we would expect to start observing a more gradual increase in both the incidence and prevalence of T2DM in Korea.