Association between timed up and go test and future incidence of disability: A nationwide representative longitudinal study in Korea.

Although previous studies examined the association between mobility and disability, they have used either subjective measure disability such as activity of daily living or instrumental activity of daily living or indirect measure such as long-term care service use with small size of participants. This study aimed to examine the association between timed up and go (TUG) test and disability incidence with national disability registration data in Korea longitudinally, by using a national representative sample. We used the National Health Insurance Service-National Health Screening Cohort (NHIS-HEALS) database of National Health Information Database. The NHIS-HEALS dataset includes disability information of National Screening Programme participants, including registration date and type of disability, which is merged from Korean National Disability Registry (KNDR). We used Cox proportional hazard models to evaluate the association between TUG and disability incidence. We constructed three models with different levels of adjustment; Model 3 was a fully adjusted model. We conducted subgroup analysis according to the risk factors for disability. The study population comprised 81,473 participants; 86 of them were newly registered to KNDR, which were observed during a mean follow-up of 4.1 ± 2.6 (maximum, 8.9) years. For 334,200.9 person-year (PY) follow-up, the disability incidence rate was 0.208 per 1,000 PY. Disability incidence was significantly higher in participants with abnormal TUG results than in those with normal TUG results. (adjusted hazard ratio [aHR] 1.600, 95% confidence interval [CI] 1.036-2.472). In subgroup analysis, the disability incidence increased in participants of normal cognition, without obesity or without cardiovascular (CV) disease. Increased incidence in disability was noted in participants with abnormal TUG results. The increase was more evident for participants with normal cognition, without obesity or CV disease.

Risk of Postoperative Gastrointestinal Bleeding and Its Associated Factors: A Nationwide Population-Based Study in Korea.

Postoperative gastrointestinal bleeding (PGIB) is a serious complication with expensive medical costs and a high mortality rate. This study aims to analyze the incidence of PGIB and its associated factors, including its relationship with postoperative analgesic use. Patients aged ≥20 years who received various kinds of surgery from 2013 to 2017 were included (n = 1,319,807). PGIB was defined by admission with ICD-10 codes of gastrointestinal bleeding plus transfusion within 2 months after surgery. A total of 3505 (0.27%) subjects had PGIB, and the incidence was much higher for those who underwent major gastrointestinal and major cardiovascular surgery (1.9% for both), followed by major head and neck (0.7%), major genitourinary (0.5%), and orthopedic surgery (0.45%). On multivariate analysis, older age, male sex, lower income, comorbidities, peptic ulcer disease, and congestive heart failure were associated with a higher risk of gastrointestinal bleeding. Among analgesics, steroid use was associated with increased postoperative bleeding risk (adjusted OR: 1.36, 95% CI: 1.25-1.48). Acetaminophen/nonsteroidal anti-inflammatory drugs, cyclooxygenase 2 inhibitors, anticonvulsants, antidepressants, and opioids were not associated with increased risk. PGIB is considerable for major surgeries, and its risk should be considered, especially for patients with older age and comorbidities and use of steroids.

Association of metabolic syndrome with mobility in the older adults: a Korean nationwide representative cross-sectional study.

We aimed to examine whether metabolic syndrome (MetS) is associated with mobility in the older adults, using the timed up and go (TUG) test which is one of the most widely used tests for evaluating mobility. This is population-based study with the National Health Insurance Service-National Health Screening Cohort database of National Health Information Database. Participants included were those who completed the TUG as part of the National Screening Program for Transitional Ages. An abnormal TUG result was defined as a time ≥ 10 s. Multiple logistic regression models were used to assess the associations between MetS and TUG results. We constructed three models with different levels of adjustment. Furthermore, we conducted a stratified analysis according to the risk. Among the 40,767 participants included, 19,831 (48.6%) were women. Mean TUG value was 8.34 ± 3.07 s, and abnormal TUG test results were observed in 4,391 (10.8%) participants; 6,888 (16.9%) participants were categorised to have MetS. The worst TUG test results were obtained in participants with three or four MetS features, and a J-shaped relationship of each MetS feature, except triglyceride (TG) and high-density lipoprotein-cholesterol (HDL-C), with TUG test was found. Participants with MetS had 18% higher likelihood of showing abnormal TUG test results in a fully adjusted model (adjusted odds ratio 1.183, 95% confidence interval 1.115-1.254). The stratified analysis revealed that participants with central obesity, high blood pressure, and normal HDL-C and TG were more likely to have abnormal TUG times. Participants with MetS had a higher risk of exhibiting abnormal TUG results, and except for HDL-C and TG, all other MetS features had a J-shaped relationship with TUG. Preventive lifestyle such as lower carbohydrate and higher protein intake, and endurance exercise is needed.

Association of anemia with mobility capacity in older adults: a Korean nationwide population-based cross-sectional study.

BACKGROUND: Over 10% of adults aged ≥65 years have anemia, as defined by the World Health Organization (WHO). As the timed up and go (TUG) test is one of the most widely used tests of mobility, this study investigated whether anemia was associated with mobility capacity assessed using the TUG test in older adults. METHODS: Subjects belonging to the Korean National Health Insurance Service-National Health Screening Cohort of the National Health Information Database were reviewed. Subjects were included if they had completed the TUG test as part of the National Screening Program for Transitional Ages in Korea. An abnormal TUG test result was defined as a time of ≥10 s and anemia was defined according to the WHO criteria as a hemoglobin (Hb) concentration of < 13.0 g/dL in men and < 12.0 g/dL in women. The association between anemia and TUG test results was evaluated using four multiple logistic regression models with different levels of adjustment. Stratified analysis according to risk factors was performed. RESULTS: The 81,473 subjects included 41,063 (50.4%) women and 40,410 (49.6%) men. Mean TUG time was 8.44 ± 3.08 s, and abnormal TUG test results were observed in 22,138 (27.2%) subjects. Mean Hb concentration was 13.72 ± 1.41 g/dL, and 10,237 (12.6%) subjects had anemia. U-shaped associations between Hb concentration and TUG test results were observed in both sexes. Subjects with anemia were 19% more likely to have abnormal TUG test results, according to the fully adjusted model (adjusted odds ratio: 1.192, 95% confidence interval: 1.137-1.247). Similar results were observed for both sexes. Stratified analysis showed that subjects with anemia were more likely to have abnormal TUG test results regardless of risk factors. CONCLUSIONS: Individuals with anemia are more likely to have abnormal TUG test results, regardless of risk factors, than individuals without anemia. U-shaped relationships between Hb concentrations and TUG test results were observed in both sexes, although the optimal Hb concentration differed between men and women.

Association of timed up and go test outcomes with future incidence of cardiovascular disease and mortality in adults aged 66 years: Korean national representative longitudinal study over 5.7 years.

BACKGROUND: The timed up and go test (TUG) is one of the most widely used tests of mobility. We aimed to examine whether the TUG is associated with cardiovascular (CV) events, CV mortality, and all-cause mortality. METHODS: Subjects in the senior cohort database of the Korean National Health Insurance Service (2002-2013) who completed the TUG as part of the National Screening Program for Transitional Ages (NSPTA) during 2007-2008 were identified. An abnormal TUG result was defined as a time ≥ 10 s. Cox proportional hazard models were used to assess the associations between TUG results and CV events, CV mortality, and all-cause mortality. RESULTS: The mean follow-up period was 5.7 years. Incidence rates of CV events in the normal and abnormal TUG groups were 7.93 and 8.98 per 1000 person-years, while CV mortality rates were 0.96 and 1.51 per 1000 person-years, respectively. In a fully adjusted model, we found that abnormal TUG results were not associated with the incidences of CV events and CV mortality. However, abnormal TUG results (≥10 s) resulted in a 2.9-fold increase in CV mortality in women (adjusted hazard ratio 2.90, 95% confidence interval 1.15-7.30). Further, participants lacking certain CV risk factors, such as current cigarette smoking, obesity, or diabetes, had a higher CV mortality rate when TUG results were abnormal. CONCLUSIONS: Abnormal TUG results in subjects aged 66 years were associated with future CV mortality in women and in subjects without obesity, diabetes, or cigarette smoking. In patient with mobility impairment, physicians should consider CV disease risk, especially in women.

Prescribing Patterns of Antihypertensives for Treatment-Naïve Patients in South Korea: From Korean NHISS Claim Data.

BACKGROUND: Several factors influence the choice of antihypertensive drugs. To facilitate the rational use of drugs it is important to assess their prescription patterns over time. This study aims to evaluate doctors' prescribing patterns of antihypertensive drugs for drug-naïve patients in South Korea. METHODS: The claims data of the Korean National Health Insurance Research Database from 1 January 2011 to 31 December 2015 were analyzed. The data virtually cover the entire South Korean population. Antihypertensive drugs were further subdivided into angiotensin receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEis), calcium channel blockers (CCBs), beta-blockers (BBs), and thiazide diuretics. The prescription pattern of antihypertensive drugs and associated factors were assessed according to the patients' characteristics, including associated comorbidities. RESULTS: A total of 2,919,162 subjects had started taking antihypertension medications during the study period. ARB was the most frequently prescribed drug (51.6%) followed by CCB (45.0%), BB (18.5%), diuretics (17.0%), and ACEi (11.7%). Most patients were prescribed with monotherapy (66.7%) rather than combination therapy (33.3%), and CCB was the most frequently prescribed monotherapy drug (25.7%). For combination therapy, ARB + CCB was the most frequently prescribed combination, and the prescription frequency was found to be increasing. In patients prescribed with combination therapy, most had been prescribed single-pill fixed-dose combination. CONCLUSION: We identified the physicians' prescription patterns of antihypertensive drugs for treatment-naïve patients. The findings of this study can lead to a rational, evidence-based, and cost-effective improvement of prescription patterns in newly diagnosed hypertensive patients.

Abdominal fatness and cerebral white matter hyperintensity.

Although obesity has been proven as a risk factor of metabolic and cardiovascular diseases, there have been few studies addressing the association between obesity and cerebral white matter hyperintensity (WMH) volume with controversial findings. In this study, we evaluated the relationship between abdominal fat distribution and WMH volume in a neurologically healthy population. We performed an observational study in a consecutive series of subjects who were examined during voluntary health check-ups between January 2006 and December 2013. We directly measured both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) using abdominal computed tomography. The WMH volumes were also recorded quantitatively. A total of 2504 subjects were included in this study. In multivariate analysis, the relationship between SAT and WMH volume remained significant (ß = -0.170, standard error [SE] = 0.065, P = .006) after adjusting for confounding factors. The protective effects of SAT on the WMH volume were more prominent in female participants (ß = -0.295, SE = 0.138, P = .033) and in severely obese participants (ß = -0.358, SE = 0.167, P = .033). Conclusively, we demonstrated a negative association between SAT and WMH volume in a healthy population.

Kidney Dysfunction Impact on White Matter Hyperintensity Volume in Neurologically Healthy Adults.

The detrimental outcomes of white matter hyperintensity (WMH) are known to be proportional to WMH volume. This study aimed to evaluate the association between kidney dysfunction and white matter hyperintensity (WMH) volume. A total of 2,203 subjects who underwent brain magnetic resonance imaging (MRI) as part of a screening health check-up was included in this study. WMH was defined as hyperintensity signals without cavity formation in the white matter on fluid-attenuated inversion recovery images. WMH volume was measured quantitatively, and data were normalized by square root transformation prior to analysis. Mean age of the subjects was 56.9 years and mean WMH volume was 2.7 cm3. Mean estimated glomerular filtration rate (eGFR) level was 78.0 ml/min/1.73 m2, and 172 subjects (7.8%) were diagnosed with moderate-to-severe kidney dysfunction (eGFR < 60). Mean Urine albumin-to-creatinine ratio (UACR) was 0.02, and 166 subjects showed significant albuminuria (UACR ≥ 0.03). Multivariate analyses showed that each of UACR, significant albuminuria, and moderate-to-severe kidney dysfunction was significantly associated with increased WMH volume (all p < 0.05). When we considered significant albuminuria and moderate-to-severe kidney dysfunction simultaneously, subjects with both significant albuminuria and moderate-to-severe kidney dysfunction had more than twice the WMH volume as did those in the other groups (all p < 0.05). Kidney dysfunction, defined by albuminuria and eGFR, was independently associated with WMH volume. Risk factors related to WMH and its detrimental outcomes should be strictly modified in subjects with kidney dysfunction, especially in those with both albuminuria and a reduced eGFR.

Serum gamma-glutamyl transferase is associated with silent brain infarcts in a healthy population.

BACKGROUND AND AIMS: Although there is substantial evidence that serum gamma-glutamyl transferase (GGT) is associated with cerebrovascular diseases, its role in silent brain infarcts (SBIs) has not been addressed. In this study, we evaluated the relationship between serum GGT and the presence of SBI in a neurologically healthy population. METHODS: We evaluated a consecutive series of healthy volunteers recruited between January 2006 and December 2013. We conducted broad examinations in the form of health check-ups, which included brain magnetic resonance imaging and laboratory examinations including assessment of GGT levels. SBI was defined as asymptomatic, well-defined lesions with a dimeter of ≥3 mm with the same signal characteristics as cerebrospinal fluid on T1- or T2-weighted images. RESULTS: A total of 3145 healthy subjects were assessed, and 260 SBI cases were identified. In multivariate analysis, the highest GGT tertile was independently associated with SBI [adjusted OR (aOR) = 1.48, 95% confidence interval (CI) = 1.02 to 2.15, p = 0.040] in a dose-response manner (p for trend = 0.037). Age and hypertension were also found to be significant factors for SBI. In a stratified analysis by sex, these positive associations of GGT levels with SBI became more prominent in the male group (aOR = 2.14, 95% CI = 1.15 to 4.00, p = 0.017), with a significantly increasing trend (p for trend = 0.028), while there was no association among female participants. CONCLUSIONS: Increased serum GGT levels were found to be associated with higher SBI prevalence in a neurologically healthy population.

KAAACI Evidence-Based Clinical Practice Guidelines for Chronic Cough in Adults and Children in Korea.

Chronic cough is common in the community and causes significant morbidity. Several factors may underlie this problem, but comorbid conditions located at sensory nerve endings that regulate the cough reflex, including rhinitis, rhinosinusitis, asthma, eosinophilic bronchitis, and gastroesophageal reflux disease, are considered important. However, chronic cough is frequently non-specific and accompanied by not easily identifiable causes during the initial evaluation. Therefore, there are unmet needs for developing empirical treatment and practical diagnostic approaches that can be applied in primary clinics. Meanwhile, in referral clinics, a considerable proportion of adult patients with chronic cough are unexplained or refractory to conventional treatment. The present clinical practice guidelines aim to address major clinical questions regarding empirical treatment, practical diagnostic tools for non-specific chronic cough, and available therapeutic options for chronic wet cough in children and unexplained chronic cough in adults in Korea.

Association between cognitive impairment and poor antihypertensive medication adherence in elderly hypertensive patients without dementia.

Adherence to antihypertensive medication is a critical factor to control blood pressure and prevent complications. However, cognitive impairment can negatively affect medication adherence. In this study, we investigated the association between cognitive function and antihypertensive medication adherence among elderly hypertensive patients using the Korean National Health Insurance Service National Sample Cohort Data of the Elderly Cohort. The study included 20,071 elderly hypertensive patients and the prevalence of poor medication adherence to antihypertensive medications was 16.4%. A multivariate logistic regression analysis showed that lower cognitive function was associated with poor medication adherence (adjusted odds ratio 0.980, 95% confidence interval 0.961-0.999). Additionally, high income levels, living in metropolitan areas, and comorbidities (such as stroke, coronary heart disease, diabetes, and dyslipidemia) were positively associated with medication adherence, while patients diagnosed with cancers showed poor medication adherence. Our study demonstrated that cognitive impairment is a possible risk factor for poor antihypertensive medication adherence, even in patients without dementia. Thus, clinicians involved with geriatric care should monitor patients' cognitive function and medication adherence. And if a patient shows cognitive impairment, clinicians need to educate patients and caregivers about the importance of proper adherence, and consider proper interventions to optimize the cognitive function of elderly patients.

Trends and Cut-Point Changes in Obesity Parameters by Age Groups Considering Metabolic Syndrome.

BACKGROUND: Non-communicable diseases (NCDs) are an important issue worldwide. Obesity has a close relationship with NCDs. Various age-related changes should be considered when evaluating obesity. METHODS: National representative cohort data from the National Health Insurance Service National Sample Cohort from 2012 to 2013 were used. Sex-specific and age group-specific (10-year intervals) means for body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WtHR) were calculated. Optimal cut-points for obesity parameters were defined as the value predicting two or more components of metabolic syndrome (except WC). RESULTS: The mean value and optimal cut-point for BMI decreased with age for men. The mean BMI value for women increased with age, but optimal cut-points showed no remarkable difference. The mean WC of men increased with age, but the optimal cut-points were similar for age groups. For women, the mean value and optimal cut-point for WC increased with age. Regarding WtHR, the mean value and optimal cut-point increased with age for men and women. Differences across age groups were larger for women. CONCLUSION: The mean values of the obesity indices and the optimal cut-points were changed according to age groups. This study supports the necessity of applying age group-specific cut-points for the various obesity parameters.

High neutrophil to lymphocyte ratios predict intracranial atherosclerosis in a healthy population.

BACKGROUND AND AIMS: Although atherosclerosis has been shown to be an inflammatory disease, intracranial atherosclerosis (ICAS) has not been well addressed. The purpose of this study was to evaluate the relationship between the neutrophil to lymphocyte ratio (NLR) and the presence of ICAS lesions in a generally healthy population. METHODS: A consecutive series of subjects, who voluntarily visited for health check-ups between January 2006 and December 2013, were selected. Brain magnetic resonance imaging, brain magnetic angiography (MRA), and blood cell count data were assessed. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels, as observed on brain MRA images. NLR was calculated based on absolute neutrophil and lymphocyte counts. RESULTS: A total of 2842 subjects were evaluated, and 76 ICAS cases were found. The median NLR was 1.52 [1.17-2.01]. In multivariate analysis, NLR remained an independent predictor of ICAS [adjusted OR (aOR) = 1.72, 95% confidence interval (CI) = 1.01-2.95, p = 0.048]. Age (aOR = 1.08, 95% CI = 1.05-1.11, p < 0.001) and hypertension (aOR = 1.81, 95% CI = 1.11-2.94, p = 0.017) were also significant factors for ICAS independent of NLR. Regarding ICAS burdens, NLR was significantly higher when the number of ICAS lesions (p = 0.017) or occlusive ICAS lesions (p = 0.005) was increased in a dose-response manner. CONCLUSIONS: A high NLR was associated with both prevalence and burdens of ICAS in a healthy population.

High neutrophil to lymphocyte ratio is associated with white matter hyperintensity in a healthy population.

High neutrophil to lymphocyte ratio (NLR) is correlated with the occurrence, morbidity and mortality of cerebrovascular disease as a marker of systemic inflammation. However, its effect on cerebral white matter hyperintensity (WMH) is unclear. We investigated high NLR burden as a surrogate marker of WMH volume in a healthy population. Healthy subjects with voluntary health check-ups between January 2006 and December 2013, including brain MRI and laboratory examination, were collected. WMH volumes were rated quantitatively. A total of 2875 subjects were enrolled, and the mean volume of WMH was 2.63±6.26mL. In multivariate linear regression analysis, NLR [ß=0.191, 95% confidence interval (CI)=0.104 to 0.279, P<0.001] remained significant after adjusting for confounders. Age (ß=0.049, 95% CI=0.045 to 0.054, P<0.001), hypertension (ß=0.191, 95% CI=0.101 to 0.281, P<0.001), diabetes (ß=0.153, 95% CI=0.045 to 0.261, P=0.006), and extracranial atherosclerosis (ß=0.348, 95% CI=0.007 to 0.688, P=0.045) were also significant independently from NLR. Additionally, the high NLR group (NLR≥1.52) was related to male sex, hypertension, diabetes, current smoking, extracranial atherosclerosis, silent brain infarct, and high WMH volumes. In conclusion, high NLR is associated with larger WMH volumes in a healthy population. Assessment of NLR may be helpful in detecting cerebral WMH burdens in high risk groups.

Cerebral white matter hyperintensity is associated with intracranial atherosclerosis in a healthy population.

BACKGROUND AND AIMS: Cerebral white matter hyperintensity (WMH) is commonly found in ischemic stroke patients, especially when accompanied by intracranial atherosclerosis (ICAS). However, the relationship between WMH and ICAS in a healthy population has not been evaluated. METHODS: A total of 3159 healthy subjects who underwent health checkups, including brain magnetic resonance imaging and angiography, were enrolled. ICAS was defined as an occlusion or more than 50% stenosis of intracranial vessels on magnetic resonance angiography. Volumes of WMH were quantitatively rated. RESULTS: Eighty-two (2.6%) subjects had ICAS. The mean age of the cohort was 56 years, and the median volume of WMH was 1.02 [0.20-2.60] mL. In a multivariate analysis, ICAS [ß = 0.331, 95% confidence interval (CI) = 0.086 to 0.576, p = 0.008] was significantly associated with WMH volumes after adjusting confounders. Age (ß = 0.046, 95% CI = 0.042 to 0.050, p < 0.001), hypertension (ß = 0.113, 95% CI = 0.017 to 0.210, p = 0.021), and diabetes (ß = 0.154, 95% CI = 0.043 to 0.265, p = 0.006) were also significant, independently of ICAS. The ICAS (+) group had more frequent vascular risk factors including hypertension, diabetes, and statin use, than the ICAS (-) group, and these tendencies increased when WMH was accompanied by ICAS. CONCLUSIONS: ICAS is associated with larger WMH volume in a healthy population. Close observation of this group and strict control of vascular risk factors are needed.

Kidney dysfunction and silent brain infarction in generally healthy adults.

BACKGROUND: The association between silent brain infarction (SBI) and estimated glomerular filtration rate (eGFR)-based kidney dysfunction has not yet been definitively confirmed. This study aimed to investigate the association in generally healthy adults without a previous history of stroke or overt kidney disease. METHODS: The data from the screening health check-up program in the Seoul National University Hospital Health Promotion Center from January 1, 2009 to December 31, 2013 were used. A total of 2594 subjects who underwent brain MRI as part of health screening were included. SBIs were identified using T2-weighted and FLAIR images. Kidney dysfunction was defined as eGFR<60ml/min/1.73m2. To assess the effect of kidney dysfunction on the small perforating branches of cerebral vessels, subgroup analysis was performed using the presence of SLI as a dependent variable. RESULTS: The mean age was 56.8±9.3years, and 1422 subjects (54.8%) were male. The mean eGFR level was 81.9±15.4ml/min/1.73m2. The prevalence rates of kidney dysfunction and SBI were 5.1% and 7.1%, respectively. A higher proportion of subjects with SBI had kidney dysfunction than subjects without SBI (14.6% vs. 4.4%). The number of SBI lesions tended to increase with the progression of kidney dysfunction (p for trend<0.001). In multivariate logistic regression analyses, kidney dysfunction was significantly associated with the presence of SBI (adjusted odd ratio=1.99 to 2.21 in all four models). The same significant association was consistently identified in subgroup analyses using silent lacunar infarction (adjusted odd ratio=1.71 to 1.87 in all four models). CONCLUSION: Kidney dysfunction was found to be an independent risk factor for the presence and number of SBI in generally healthy adults. Physicians treating patients with a decreased creatinine-based eGFR level should try to identify and modify the coexisting risk factors of stroke followed by SBI.

Regional variations in frequency of glycosylated hemoglobin (HbA1c) monitoring in Korea: A multilevel analysis of nationwide data.

PURPOSE: Suboptimal frequency of glycosylated hemoglobin (HbA1c) monitoring is associated with poor diabetes control. We aimed to analyze compliance to HbA1c testing guidelines and explore associated individual and area-level determinants, focusing on regional variation. METHODS: This cross-sectional study between the period of 2012-2013 was conducted by using the Korean National Health Insurance Research Database, and included 45,634 patients diagnosed with diabetes mellitus, who were prescribed any anti-diabetic medications, including insulin. We calculated the proportion of each HbA1c testing frequency (≥1, ≥2, or ≥4 times per year) stratified by 17 administrative regions. Multilevel and multivariate logistic analyses were performed with regional (proportion of farmer population) and individual characteristics (age, sex, income level, duration of diabetes, and most visited medical institution). RESULTS: Overall, 67.3% of the patients received≥1 HbA1c test per year; 37.8% and 6.1% received ≥2 and ≥4 tests per year, respectively. Those managed in secondary-level hospitals or clinics and those living in rural areas were less likely to receive HbA1c testing. Even after adjusting for individual and regional level characteristics, significant area level variation was observed (variance participant coefficients were 7.91%, 9.58%, and 14.43% for testing frequencies of ≥1, ≥2, and ≥4 times a year, respectively). CONCLUSIONS: The frequency of HbA1c monitoring is suboptimal in Korea, especially in rural areas. Moreover, significant regional variation was observed, implying a contextual effect. This suggests the need for developing policy actions to improve HbA1c monitoring. In particular, access to HbA1c testing in rural primary care clinics must be improved.

Correction: Kidney dysfunction and cerebral microbleeds in neurologically healthy adults.

[This corrects the article DOI: 10.1371/journal.pone.0172210.].

Middleware Design for Swarm-Driving Robots Accompanying Humans.

Research on robots that accompany humans is being continuously studied. The Pet-Bot provides walking-assistance and object-carrying services without any specific controls through interaction between the robot and the human in real time. However, with Pet-Bot, there is a limit to the number of robots a user can use. If this limit is overcome, the Pet-Bot can provide services in more areas. Therefore, in this study, we propose a swarm-driving middleware design adopting the concept of a swarm, which provides effective parallel movement to allow multiple human-accompanying robots to accomplish a common purpose. The functions of middleware divide into three parts: a sequence manager for swarm process, a messaging manager, and a relative-location identification manager. This middleware processes the sequence of swarm-process of robots in the swarm through message exchanging using radio frequency (RF) communication of an IEEE 802.15.4 MAC protocol and manages an infrared (IR) communication module identifying relative location with IR signal strength. The swarm in this study is composed of the master interacting with the user and the slaves having no interaction with the user. This composition is intended to control the overall swarm in synchronization with the user activity, which is difficult to predict. We evaluate the accuracy of the relative-location estimation using IR communication, the response time of the slaves to a change in user activity, and the time to organize a network according to the number of slaves.

Kidney dysfunction and cerebral microbleeds in neurologically healthy adults.

INTRODUCTION: Cerebral microbleed (CMB) is a potent risk factor for overt cerebrovascular disease. Although some studies indicated the possible role of renal dysfunction as a risk factor of CMB, the findings could not be generalized. This study aimed to investigate the association between renal dysfunction and cerebral microbleed (CMB) in neurologically healthy adults. MATERIALS AND METHODS: A total of 2,518 subjects who underwent brain MRI as part of health screening were involved in the study. CMBs were defined as well-demarcated focal areas of low signal intensity with associated blooming on the T2-weighted MRI measuring less than 5mm in diameter. The glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease formula. Kidney function was classified as normal (≥90), mild (60 to 89.9), moderate (30 to 59.9), and severe (<30 mL/min/1.73 m2) renal dysfunction according to the GFR. RESULTS: The mean age of the participants was 57.5 ± 8.3 years (ranged 40 to 79), and 1,367 subjects (54.3%) were male. The mean GFR level was 81.5 ± 15.5, and the prevalence of CMB was 4.1% (n = 103). Subjects with CMB demonstrated a higher proportion of moderate-to-severe renal dysfunction than those without CMB (15.5% vs. 5.0%, p < 0.001). In the multivariate logistic regression analysis, moderate-to-severe renal dysfunction showed a significant association with CMB (adjusted odd ratio = 2.63; p = 0.008). Furthermore, a decrease in the GFR level was associated with an increasing trend of the presence of CMB (p for trend = 0.031) and number of CMB lesions (p for trend = 0.003). CONCLUSIONS: Renal dysfunction was significantly associated with the presence of CMB in neurologically healthy adults. More studies are needed to evaluate if treatment of kidney disease and risk factor modification may prevent further progress of CMB.