OBJECTIVES: This study evaluated and validated the reliability of smartphones as measuring equipment for the dorsi-plantar flexion of ankle joint position sense (JPS) ability. METHODS: The subjects were 20 healthy young students in their 20s. We confirmed the concurrent validity by comparison with existing electrogoniometer data. The reliability of the smartphone was confirmed using the test-retest method. RESULTS: In the case of dorsiflexion, there was no significant difference between the smartphone and electrogoniometer groups (p > 0.05). Regarding the correlation, it was significantly high (r = 0.65, p < 0.05), and ICC(3,1) was good (ICC(3,1) = 0.79). For the case of plantar flexion, there was no significant difference between the smartphone and electrogoniometer groups (p > 0.05), the correlation was significantly high (r = 0.69, p < 0.05), and the ICC(3,1) was very good (ICC(3,1) = 0.82). In the case of dorsiflexion, there was no significant difference between test and retest (p > 0.05), the correlation was intermediate (r = 0.59, p < 0.05), and the ICC(3,1) value was good (ICC(3,1) = 0.74). For plantar flexion, there was no significant difference between test and retest (p > 0.05), the correlation was significantly high (r = 0.63, p < 0.05), and the ICC(3,1) was good (ICC(3,1) = 0.76). CONCLUSIONS: The results showed that smartphones provide high validity and reliability as measurement equipment for JPS of dorsi-plantar flexion of the ankle. Finally, the study also considers that smartphone-based JPS measuring methods may replace the traditional and expensive methods that are currently being used for the same purpose.
Ankle Joint ; Ankle* ; Humans ; Joints* ; Methods ; Proprioception* ; Reproducibility of Results ; Smartphone*

Genomic epidemiology is defined as "an evolving field of inquiring that uses the systematic application of epidemiologic methods and approaches in population-based studies of the impact of human genetic variation on health and disease (Khoury, 1998) ". Most human diseases are caused by the intricate interaction among environmental exposures and genetic susceptibility factors. Susceptibility genes involved in disease pathogenesis are categorized into two groups: high penetrance genes (i.e., BRAC1, RB, etc.) and low penetrance genes (i.e., GSTs, Cyps, XRCC1, ets.), and low penetrance susceptibility genes has the higher priority for epidemiological research due to high population attributable risk. In this paper, the summarized results of the association study between single nucleotide polymorphisms (SNPs) and breast cancer in Korea were introduced and the international trends of genomic epidemiology research were reviewed with an emphasis on internet-based case-control and cohort consortium.
Breast Neoplasms ; Case-Control Studies ; Cohort Studies ; Environmental Exposure ; Epidemiologic Methods ; Epidemiology* ; Genetic Predisposition to Disease ; Genetic Variation ; Genome ; Humans ; Korea ; Penetrance ; Polymorphism, Single Nucleotide

Biomarkers are characteristic biological properties that can be detected and measured in a variety of biological matrices in the human body, including the blood and tissue, to give an indication of whether there is a threat of disease, if a disease already exists, or how such a disease may develop in an individual case. Along the continuum from exposure to clinical disease and progression, exposure, internal dose, biologically effective dose, early biological effect, altered structure and/or function, clinical disease, and disease progression can potentially be observed and quantified using biomarkers. While the traditional discovery of biomarkers has been a slow process, the advent of molecular and genomic medicine has resulted in explosive growth in the discovery of new biomarkers. In this review, issues in evaluating biomarkers will be discussed and the biomarkers of environmental exposure, early biologic effect, and susceptibility identified and validated in epidemiological studies will be summarized. The spectrum of genomic approaches currently used to identify and apply biomarkers and strategies to validate genomic biomarkers will also be discussed.
Disease Progression ; Environmental Exposure ; *Epidemiologic Studies ; *Genetic Markers ; Humans ; Molecular Epidemiology/*methods ; Neoplasms/epidemiology ; Republic of Korea/epidemiology

The age-standardized incidence and mortality rates of gastric cancer have been decreasing worldwide. However, due to the rapid increase in the aging population, the absolute number of cases is actually increasing, and some countries, including Korea, show a divergent trend in the incidence of gastric cancer in younger generations. Gastric cancer is the second most common cancer in Korea. In the present review, several epidemiologic factors associated with the risk of gastric cancer are evaluated, including family history of gastric cancer, Helicobacter pylori infection, cigarette smoking, and adverse dietary factors. The practice of and participation in gastric cancer screening are reviewed. Prevention strategies based on evidence from Korean epidemiologic studies and early detection by regular screening are important for the reduction of the burden from gastric cancer.
Aging ; Diagnosis ; Epidemiologic Factors ; Epidemiologic Studies ; Epidemiology* ; Family Characteristics ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Mass Screening* ; Mortality ; Risk Factors ; Smoking ; Stomach Neoplasms*

The age-standardized incidence and mortality rates of gastric cancer have been decreasing worldwide. However, due to the rapid increase in the aging population, the absolute number of cases is actually increasing, and some countries, including Korea, show a divergent trend in the incidence of gastric cancer in younger generations. Gastric cancer is the second most common cancer in Korea. In the present review, several epidemiologic factors associated with the risk of gastric cancer are evaluated, including family history of gastric cancer, Helicobacter pylori infection, cigarette smoking, and adverse dietary factors. The practice of and participation in gastric cancer screening are reviewed. Prevention strategies based on evidence from Korean epidemiologic studies and early detection by regular screening are important for the reduction of the burden from gastric cancer.
Aging ; Diagnosis ; Epidemiologic Factors ; Epidemiologic Studies ; Epidemiology* ; Family Characteristics ; Helicobacter pylori ; Humans ; Incidence ; Korea ; Mass Screening* ; Mortality ; Risk Factors ; Smoking ; Stomach Neoplasms*

OBJECTIVES: Self-reported disease history is often used in epidemiological studies. In this study, we acquired the hospital records of subjects who self-reported stroke or myocardial infarction (MI) and evaluated the validity of the participants’ self-reported disease history. We also determined the level of agreement between specialists and non-specialists. METHODS: Among the participants in the Health Examinees study, 1488 subjects self-reported stroke or MI during 2012-2017, and medical records were acquired for the 429 subjects (28.8%) who agreed to share their medical information. Each record was independently assigned to 2 medical doctors for review. The records were classified as ‘definite,’‘possible,’ or ‘not’ stroke or MI. If the doctors did not agree, a third doctor made the final decision. The positive predictive value (PPV) of self-reporting was calculated with the doctors’ review as the gold standard. Kappa statistics were used to compare the results between general doctors and neurologists or cardiologists. RESULTS: Medical records from 208 patients with self-reported stroke and 221 patients with self-reported MI were reviewed. The PPV of self-reported disease history was 51.4% for stroke and 32.6% for MI. If cases classified as ‘possible’ were counted as positive diagnoses, the PPV was 59.1% for stroke and 33.5% for MI. Kappa statistics showed moderate levels of agreement between specialists and non-specialists for both stroke and MI. CONCLUSIONS The validity of self-reported disease was lower than expected, especially in those who reported having been diagnosed with MI. Proper consideration is needed when using these self-reported data in further studies.

Chronic neuroinflammation is an integral pathological feature of major neurodegenerative diseases. The recruitment of microglia to affected brain regions and the activation of these cells are the major events leading to disease-associated neuroinflammation. In a previous study, we showed that neuron-released alpha-synuclein can activate microglia through activating the Toll-like receptor 2 (TLR2) pathway, resulting in proinflammatory responses. However, it is not clear whether other signaling pathways are involved in the migration and activation of microglia in response to neuron-released alpha-synuclein. In the current study, we demonstrated that TLR2 activation is not sufficient for all of the changes manifested by microglia in response to neuron-released alpha-synuclein. Specifically, the migration of and morphological changes in microglia, triggered by neuron-released alpha-synuclein, did not require the activation of TLR2, whereas increased proliferation and production of cytokines were strictly under the control of TLR2. Construction of a hypothetical signaling network using computational tools and experimental validation with various peptide inhibitors showed that beta1-integrin was necessary for both the morphological changes and the migration. However, neither proliferation nor cytokine production by microglia was dependent on the activation of beta1-integrin. These results suggest that beta1-integrin signaling is specifically responsible for the recruitment of microglia to the disease-affected brain regions, where neurons most likely release relatively high levels of alpha-synuclein.
Animals ; Antigens, CD29/genetics/*metabolism ; Cell Line, Tumor ; *Cell Movement ; Cells, Cultured ; Culture Media, Conditioned/*pharmacology ; Gene Regulatory Networks ; Humans ; Mice ; Mice, Inbred C57BL ; Microglia/drug effects/metabolism/*physiology ; Neurons/*metabolism ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Toll-Like Receptor 2/metabolism ; alpha-Synuclein/*pharmacology

Purpose: Dietary calcium intake has been suggested to be protective against the development of colorectal cancer. The mean dietary calcium intake of Koreans is 490 mg/day, which is far below the recommended calcium intake of 700-800 mg/day. In this study, we explored the relationship between dietary calcium intake and colorectal cancer development in Koreans with relatively low calcium intake compared with individuals in Western countries. Materials and Methods: The Health Examinees Study, a large-scale genomic community-based prospective cohort study, was designed to identify the general characteristics of major chronic diseases in Koreans. A total of 119,501 participants aged 40-69 years recruited between 2004 and 2013 were included in this analysis. The calcium intake level was categorized using the Dietary Reference Intakes for Koreans (KDRIs). The Cox proportional hazards regression model was used to estimate the hazard ratio (HR) and the corresponding 95% confidence intervals (CIs) for colorectal cancer risk, adjusting for potential confounders. Results: In the multivariable-adjusted model, compared with the group that consumed less than the recommended amount of calcium, the group that consumed more than the recommended intake of calcium showed a significant reduction in the risk of colorectal cancer in women. (HR, 0.54; 95% CI, 0.31 to 0.95). Among men, however, no significant association was observed between dietary calcium intake and colorectal cancer risk (HR, 0.89; 95% CI, 0.54 to 1.45). Conclusion Korean women who adhere to the recommended intake of calcium showed a reduced risk of colorectal cancer.

Background: Comparison of the prevalence of cardiometabolic disorders (CMDs) and comorbidities in Korea and the United States (US) can be an important indicator for forecasting future risk of cardiovascular events in Korea. This study aimed to estimate and compare the prevalence of hypertension, diabetes mellitus (DM), dyslipidemia, obesity, and metabolic syndrome (MetS) in Korea and the US. Methods: A total of 15,872 individuals from the US National Health and Nutrition Examination Survey (NHANES) 2003–2014 and 26,492 from the Korea NHANES (KNHANES) 2007–2014 were included. Additionally, 164,339 (139,345 from the Health Examinees-Gem Study and 24,994 from the Cardiovascular Disease Association Study) participants enrolled in the Korea Genome and Epidemiology Study were included to investigate the differences of CMDs between urban and rural regions. To estimate the age-standardized prevalence of CMDs in individuals aged 40–69 years, direct standardization using the World Health Organization standard population was performed. Results: The prevalence of CMDs was lower in Korea than the US (hypertension 49.9% vs.56.8%; DM 13.4% vs. 14.3%; hypercholesterolemia 16.8% vs. 17.8%; obesity 36.2% vs. 38.6%; and MetS 29.4% vs. 36.5%). According to the median survey years, dyslipidemia has become more prevalent in Korea than in the US since 2010. The prevalence of CMDs was greater in rural than that in urban areas in Korea. Conclusion The prevalence of dyslipidemia in Korea exceeded that of the US after 2010, which was associated with increasing burden of cardiovascular events. The present study suggests that further preventive strategies are needed to mitigate the prevalence of CMDs in Korea.

OBJECTIVES: The purpose of this study was to explore the association between adherence to 2 cancer prevention recommendations and cancer risk. METHODS: In total, 104,386 individuals aged 40-69 years old who were recruited between 2004 and 2013 in the Health Examinees-Gem study were included. Adherence scores were constructed based on 8 items from the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) cancer prevention recommendations, including body weight, physical activity, diet, alcohol consumption and breastfeeding, and on 6 items from the Korean cancer prevention guidelines (smoking status, eating vegetables and fruits, salty foods, alcohol intake, physical activity, and body weight). A Cox proportional hazards model was used to estimate the associations between adherence scores and the risk of total and 5 major cancers. RESULTS: The multivariable hazard ratio (HR) for total cancer with the high adherence score versus the lowest score (4.25-7.00 vs. 0.00-3.25) for the WCRF/AICR guidelines was 0.91 (95% confidence interval [CI], 0.82 to 1.00) in men. A reduced breast cancer risk was observed among women with the highest score. Men within the highest category of the Korean cancer prevention guideline score (3.25-6.00) had an HR of 0.80 (95% CI, 0.73 to 0.88) for developing total cancer compared to men within the lowest score (0.00-2.50). The higher adherence group among men showed lower risks of developing stomach, colorectal, and lung cancers. CONCLUSIONS Adhering to guidelines for cancer prevention can help to reduce the risk of developing cancer in Korean men. The association might differ by cancer type and gender.