Epidemiology and treatment outcome of ANCA-associated vasculitis in South Korea: a nationwide, population-based cohort study.

OBJECTIVES: To investigate the epidemiological features of granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) in South Korea. METHODS: We identified the index cases of GPA and MPA using the 2010-2018 Korean National Health Insurance Service database and the Rare Intractable Disease registry for the entire Korean population. Each disease's incidence and prevalence rates and trends over time were analysed. To assess the impact of disease on morbidity and mortality, a comparator group comprising the general population was established using nearest-neighbour matching by age, sex, income, and comorbidity index, at a 5:1 ratio. Morbidity outcomes included the initiation of renal replacement therapy and admission to the intensive care unit. RESULTS: We identified 546 and 795 patients with GPA and MPA, respectively. The incidence rates of both diseases increased with age, with peak incidence rates observed among patients aged ≥70 years. The incidence of MPA increased continuously over time, whereas that of GPA showed no significant changes. During the observation period, 132 (28.7%) and 277 (41.1%) patients in the GPA and MPA groups, respectively, died, which were significantly higher than that in the general population (standardised mortality ratio: 3.53 and 5.58, respectively) and comparator group (hazard ratio: 4.02 and 5.64, respectively). Higher mortality and morbidity rates were observed among patients with MPA than among those with GPA. CONCLUSIONS: In South Korea, the incidence of MPA has increased over time. Although both GPA and MPA had high rates of mortality and morbidity, MPA has a poorer prognosis than GPA.

Association between body composition and subsequent cardiovascular diseases among 5-year breast cancer survivors.

BACKGROUND AND AIMS: Cardiovascular disease (CVD) remain one of the leading causes of mortality in breast cancer survivors. This study aimed to investigate the association between body composition and subsequent CVD in breast cancer survivors. METHODS AND RESULTS: A retrospective cohort study of more than 70 thousand 5-year breast cancer survivors aged 40 years or older was conducted using data from the National Health Insurance Service of South Korea. Based on the percentage of predicted lean body mass (pLBMP), appendicular skeletal muscle mass (pASMP), and body fat mass (pBFMP), which were calculated using prediction equations with anthropometric data and health habits, groups were equally divided into quartiles. The risk of CVD was evaluated using multivariate Cox proportional hazards regression. Compared to those with the lowest pLBMP and pASMP, those with the highest pLBMP and pASMP had a 38% and 42% lower risk of CVD, respectively. In contrast, those with the highest pBFMP had a 57% higher risk of CVD compared to those with the lowest pBFMP. Each 1 % increase in pLBMP and pASMP was associated with a decreased risk of CVD [pLBMP, adjusted hazard ratio (aHR): 0.96, 95% CI 0.94-0.98, p < 0.05; pASMP, aHR: 0.91, 95% CI 0.87-0.95, p < 0.05] while each 1 % increase in pBFMP was associated with the increased risk of CVD (aHR: 1.05, 95% CI 1.03-1.07, p < 0.01). CONCLUSION: In this cohort study, a high pLBMP, a high pASMP, and a low pBFMP were associated with a lower risk of CVD.

Association between antibiotic use and subsequent risk of prostate cancer: A retrospective cohort study in South Korea.

OBJECTIVES: Several studies suggest that antibiotic use may affect overall cancer incidence, but the association between antibiotics and prostate cancer is still unclear. This retrospective cohort study aimed to assess the association between antibiotics and the risk of prostate cancer. METHODS: A population-based retrospective cohort study was conducted using the Korean National Health Insurance Service (NHIS) database. 1 032 397 individuals were followed up from January 1, 2007, to December 31, 2019. Multivariable Cox hazards regression was utilized to calculate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of prostate cancer according to accumulative days of antibiotic use and the number of antibiotic classes used from 2002 to 2006. RESULTS: Individuals who used antibiotics for 180 or more days had a higher risk of prostate cancer (aHR, 1.46; 95% CI, 1.11-1.91) than those who did not use antibiotics. Also, individuals who used four or more kinds of antibiotics had a higher risk of prostate cancer (aHR, 1.18; 95% CI, 1.07-1.30) than antibiotic non-users. An overall trend was observed among participants who underwent health examinations. CONCLUSIONS: Our findings suggest that long-term use of antibiotics may affect prostate cancer incidence. Further studies are needed to improve understanding of the association between antibiotic use and prostate cancer incidence.

Association of allergic disease with Parkinson's disease: A nationally representative retrospective cohort study.

BACKGROUND: The association of allergic diseases such as allergic rhinitis, asthma, and atopic dermatitis with Parkinson's disease (PD) risk is yet unclear. In the few preceding studies, a short follow-up duration was followed for a relatively small study population, and lifestyle behaviors were not adjusted for. Therefore, there is a need for large-scale observation studies on the association of allergic disease with PD risk after considering lifestyle behaviors. METHODS: The study population consisted of 398,936 participants aged 40 years or older who underwent health screening before 1 January 2005 from the Korean National Health Insurance Service database. Starting from 1 January 2005, all participants were followed up until the date of PD event, death, or 31 December 2019. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for the risk of PD were calculated using multivariable Cox proportional hazards regression. RESULTS: Compared to non-allergic disease participants, allergic disease patients had a higher risk for PD (aHR 1.18, 95% CI 1.07-1.30) and especially, allergic rhinitis patients had a higher risk for PD (aHR 1.14, 95% CI 1.00-1.29). Allergic disease was associated with a higher risk for PD (aHR 1.24, 95% CI 1.01-1.52) among participants who were never smokers, did not consume alcohol, and exercised regularly. CONCLUSIONS: Allergic rhinitis was associated with a higher risk for PD compared to participants without allergic rhinitis. This risk-increasing association of allergic rhinitis with PD was preserved even among people with healthy lifestyle behaviors.

Effect of changes in sleeping behavior on skeletal muscle and fat mass: a retrospective cohort study.

BACKGROUND: An association between sleep behaviors and muscle-fat mass is continuously interesting topic. METHODS: Based on the survey on sleep behaviors (quality and duration), the poor quality of sleep was evaluated when the subject did not feel satisfied after sleep, while the good quality was evaluated as they feel refreshed. A total of 19,770 participants were divided into the four groups according to changes in sleep quality: Good-to-Good (those who continuously maintained good quality), Good-to-Poor (those who reported initial good quality but subsequently reported a poor quality), Poor-to-Poor (those who continuously maintained poor quality), and Poor-to-Good (those who reported improved quality of sleep). As changes in skeletal muscle and fat mass index [kg/m2] were estimated by a validated prediction equation, multiple linear regression was used to calculate adjusted mean (adMean) of muscle and fat mass according to changes in sleep behavior. RESULTS: When sleep duration decreased and quality of sleep deteriorated (from good to poor), fat mass index significantly increased (adMean: 0.087 for the Good-to-Good group and 0.210 for the Good-to-Poor group; p-value = 0.006). On the other hand, as the quality of sleep deteriorated, skeletal muscle mass more decreased despite the maintained sleep duration (adMean: -0.024 for the Good-to-Good group and - 0.049 for the Good-to-Poor group; p-value = 0.009). CONCLUSION: Our results showed that changes in sleep quality and duration affect changes in muscle and fat mass. Thus, we suggest maintaining a good quality of sleep, even if sleep duration is reduced, to preserve muscle mass and inhibit the accumulation of fat.

Combined Associations of Changes in Noncombustible Nicotine or Tobacco Product and Combustible Cigarette Use Habits With Subsequent Short-Term Cardiovascular Disease Risk Among South Korean Men: A Nationwide Cohort Study.

BACKGROUND: The associations of changes in noncombustible nicotine or tobacco product (NNTP) and combustible cigarette (CC) use habits with subsequent cardiovascular disease (CVD) risk are still unclear. METHODS: The study population consisted of 5 159 538 adult men who underwent health screening examinations during both the first (2014-2015) and second (2018) health screening periods from the Korean National Health Insurance Service database. All participants were divided into continual CC-only smokers, CC and NNTP users, recent (<5 years) CC quitters without NNTP use, recent CC quitters with NNTP use, long-term (≥5 years) CC quitters without NNTP use, long-term CC quitters with NNTP use, and never smokers. Propensity score matching analysis was conducted to further compare CVD risk among CC quitters according to NNTP use. Starting from the second health screening date, participants were followed up until the date of CVD event, death, or December 31, 2019, whichever came earliest. Multivariable Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% CIs for CVD risk according to changes in NNTP and CC smoking habits. RESULTS: Compared with continual CC-only smokers, CC and NNTP users (aHR, 0.83 [95% CI, 0.79-0.88]) and initial CC smokers who quit CCs and switched to NNTP use only (recent CC quitters with NNTP use, aHR, 0.81 [95% CI, 0.78-0.84]) had lower risk for CVD. After propensity score matching, recent CC quitters with NNTP use (aHR, 1.31 [95% CI, 1.01-1.70]) had higher risk for CVD than recent CC quitters without NNTP use. Similarly, compared with long-term CC quitters without NNTP use, long-term CC quitters with NNTP use (aHR, 1.70 [95% CI, 1.07-2.72]) had higher CVD risk. CONCLUSIONS: Switching to NNTP use among initial CC smokers was associated with lower CVD risk than continued CC smoking. On CC cessation, NNTP use was associated with higher CVD risk than CC quitting without NNTPs. Compared with CC smokers who quit without NNTP use, CC quitters who use NNTPs may be at higher future CVD risk.

Association of the combined effects of air pollution and changes in physical activity with cardiovascular disease in young adults.

AIMS: Little is known about the trade-off between the health benefits of physical activity (PA) and the potential harmful effects of increased exposure to air pollution during outdoor PA. We examined the association of the combined effects of air pollution and changes in PA with cardiovascular disease (CVD) in young adults. METHODS AND RESULTS: This nationwide cohort study included 1 469 972 young adults aged 20-39 years. Air pollution exposure was estimated by the annual average cumulative level of particulate matter (PM). PA was calculated as minutes of metabolic equivalent tasks per week (MET-min/week) based on two consecutive health examinations from 2009 to 2012. Compared with the participants exposed to low-to-moderate levels of PM2.5 or PM10 who continuously engaged in ≥1000 MET-min/week of PA, those who decreased their PA from ≥1000 MET-min/week to 1-499 MET-min/week [PM10 adjusted hazard ratio (aHR) 1.22; 95% confidence interval (CI) 1.00-1.48] and to 0 MET-min/week (physically inactive; PM10 aHR 1.38; 95% CI 1.07-1.78) had an increased risk of CVD (P for trend <0.01). Among participants exposed to high levels of PM2.5 or PM10, the risk of CVD was elevated with an increase in PA above 1000 MET-min/week. CONCLUSION: Reducing PA may lead to subsequent elevation of CVD risk in young adults exposed to low-to-moderate levels of PM2.5 or PM10, whereas a large increase in PA in a high-pollution environment may adversely affect cardiovascular health.

Association between physical activity and subsequent cardiovascular disease among 5-year breast cancer survivors.

PURPOSE: To examine the association of physical activity among long-term breast cancer survivors on the occurrence of subsequent cardiovascular disease (CVD). METHODS: We investigated the risk of CVD among 39,775 breast cancer patients who were newly diagnosed in 2006 and survived until 2011 within the Korean National Health Insurance Service database. Patients were followed up from 5 years after breast cancer diagnosis to the date of CVD event, death, or December 31, 2018, whichever came earliest. Every 500 MET-mins/week correspond to 152, 125, and 62.5 min per week of light-, moderate-, and vigorous-intensity physical activity, respectively. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CVD were calculated using Cox proportional hazards regression by physical activity levels. RESULTS: Compared with those with physical activity of 0 MET-min/week, those with 1-499 (aHR 0.82, 95% CI 0.69-0.98), 500-999 (aHR 0.75, 95% CI 0.63-0.90), and ≥ 1,000 (aHR 0.76, 95% CI 0.63-0.93) MET-min/week of PA had lower risk of CVD. Higher levels of PA were associated with lower risk of stroke (p for trend = 0.016). The benefits of PA on obese and overweight breast cancer survivors were smaller than those in normal weight survivors. The frequency of moderate-to-vigorous physical activity (MVPA) showed a reverse J-curve association with CVD, and the best benefit occurred in the 3-4 times MVPA per week group (aHR 0.59, 95% CI 0.46-0.74). CONCLUSIONS: The study showed that even small amounts of PA may be beneficial in potentially decreasing the risk of CVD, CHD, and stroke in breast cancer survivors. Our result will be useful to prescribe and delivery exercise among long-term breast cancer survivors.

Association of particulate matter with autoimmune rheumatic diseases among adults in South Korea.

OBJECTIVE: The primary objective of this study was to investigate adverse effects of ambient particulate matter of various sizes on the incidence of the prevalent autoimmune rheumatic diseases (AIRDs): RA, AS and SLE. METHODS: We investigated 230 034 participants in three metropolitan cities of South Korea from the National Health Insurance Service-National Sample Cohort (NHIS-NSC). Starting from January 2010, subjects were followed up until the first event of prevalent AIRDs, death, or December 2013. The 2008-2009 respective averages of particulate matter2.5 (<2.5 µm) and particulate mattercoarse (2.5 µm to 10 µm) were linked with participants' administrative district codes. Adjusted hazard ratios (aHRs) and 95% CIs were estimated using Cox regression analysis in one- and two-pollutant models. RESULTS: Adjusted for age, sex, region, and household income, in the two-pollutant model, RA incidence was positively associated with the 10 µg/m³ increment of particulate matter2.5 (aHR = 1.74, 95% CI: 1.06, 2.86), but not with particulate mattercoarse (aHR = 1.27, 95% CI: 0.87, 1.85). In the one-pollutant model, the elevated incidence rate of RA was slightly attenuated (particulate matter2.5 aHR = 1.61, 95% CI: 0.99, 2.61; particulate mattercoarse aHR = 1.13, 95% CI: 0.80, 1.61), with marginal statistical significance for particulate matter2.5. The RA incidence was also higher in the 4th quartile group of particulate matter2.5 compared with the first quartile group (aHR = 1.83, 95% CI: 1.07, 3.11). Adverse effects from particulate matter were not found for AS or SLE in either the one- or two-pollutant models. CONCLUSION: The important components of particulate matter10 associated with RA incidence were the fine fractions (particulate matter2.5); no positive association was found between particulate matter and AS or SLE.

Explaining the Rationale of Deep Learning Glaucoma Decisions with Adversarial Examples.

PURPOSE: To illustrate what is inside the so-called black box of deep learning models (DLMs) so that clinicians can have greater confidence in the conclusions of artificial intelligence by evaluating adversarial explanation on its ability to explain the rationale of DLM decisions for glaucoma and glaucoma-related findings. Adversarial explanation generates adversarial examples (AEs), or images that have been changed to gain or lose pathologic characteristic-specific traits, to explain the DLM's rationale. DESIGN: Evaluation of explanation methods for DLMs. PARTICIPANTS: Health screening participants (n = 1653) at the Seoul National University Hospital Health Promotion Center, Seoul, Republic of Korea. METHODS: We trained DLMs for referable glaucoma (RG), increased cup-to-disc ratio (ICDR), disc rim narrowing (DRN), and retinal nerve fiber layer defect (RNFLD) using 6430 retinal fundus images. Surveys consisting of explanations using AE and gradient-weighted class activation mapping (GradCAM), a conventional heatmap-based explanation method, were generated for 400 pathologic and healthy patient eyes. For each method, board-trained glaucoma specialists rated location explainability, the ability to pinpoint decision-relevant areas in the image, and rationale explainability, the ability to inform the user on the model's reasoning for the decision based on pathologic features. Scores were compared by paired Wilcoxon signed-rank test. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUC), sensitivities, and specificities of DLMs; visualization of clinical pathologic changes of AEs; and survey scores for locational and rationale explainability. RESULTS: The AUCs were 0.90, 0.99, 0.95, and 0.79 and sensitivities were 0.79, 1.00, 0.82, and 0.55 at 0.90 specificity for RG, ICDR, DRN, and RNFLD DLMs, respectively. Generated AEs showed valid clinical feature changes, and survey results for location explainability were 3.94 ± 1.33 and 2.55 ± 1.24 using AEs and GradCAMs, respectively, of a possible maximum score of 5 points. The scores for rationale explainability were 3.97 ± 1.31 and 2.10 ± 1.25 for AEs and GradCAM, respectively. Adversarial example provided significantly better explainability than GradCAM. CONCLUSIONS: Adversarial explanation increased the explainability over GradCAM, a conventional heatmap-based explanation method. Adversarial explanation may help medical professionals understand more clearly the rationale of DLMs when using them for clinical decisions.

Associations between alcohol consumption and cardiovascular disease among long-term survivors of colorectal cancer: a population-based, retrospective cohort study.

BACKGROUND: There is no evidence whether it is best to stop drinking alcohol at all or whether it is okay to drink a little in that light-to-moderate alcohol use was associated with low cardiovascular disease (CVD) compared to non-drinker among colorectal cancer (CRC) survivors, who are regarded as vulnerable to CVD. Therefore, we evaluated the association between alcohol consumption and incident CVD among long-term survivors of CRC. METHODS: This population-based, retrospective cohort study utilized data from the Korean National Insurance Service of 20,653 long-term survivors of CRC diagnosed between 2006 and 2012. Participants were followed up to the date of CVD, death, or December 31, 2018. All patients were categorized according to their daily alcohol consumption (g/day). The outcomes were incident CVD, including ischemic heart disease (IHD) and ischemic and hemorrhagic stroke, analyzed using the Cox proportional hazards regression after adjusting for cardiovascular risk factors and history of chemotherapy and radiotherapy. RESULTS: There was no association between alcohol consumption and incident CVD among long-term survivors of CRC. Additionally, hazardous alcohol consumption (≥ 40 g/day in male patients and ≥ 20 g/day in female patients) was associated with increased CVD, ischemic stroke, and hemorrhagic stroke (adjusted hazard ratio [95% confidence interval]: 1.51 [1.15-1.97], 1.60 [1.03-2.48], and 2.65 [1.25-5.62], respectively) compared with non-drinkers. CONCLUSION: No discernable protective association was found between alcohol consumption and incident CVD for even light-to-moderate drinking among long-term survivors of CRC. Alcohol consumption ≥40 g/day in male patients and ≥ 20 g/day in female patients was associated with an increased risk of stroke compared with non-drinkers. These novel results provide useful evidence when advising survivors of CRC regarding alcohol use.

Association of hemoglobin level with fracture: a nationwide cohort study.

INTRODUCTION: The association between hemoglobin (Hb) level including anemia and fracture has not been studied thoroughly. MATERIALS AND METHODS: 197, 187 adults ≥ 50 years from the National Health Insurance Service of Korea were studied. Hb was determined during health screening examinations in 2004 or 2005. From 1 January 2006, participants were followed up for fracture until 31 December 2013. Hb levels (g/dL) were categorized into five groups, with normal hemoglobin levels subdivided into three groups (low normal, normal, and high normal Hb): < 13, ≥ 13 to < 14, ≥ 14 to < 16, ≥ 16 to < 17, 17 for men and < 12, ≥ 12 to < 13, ≥ 13 to < 14, ≥ 14 to < 16, ≥ 16 for women. Anemia was defined as Hb < 13 g/dL and < 12 g/dL for men and women, respectively. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for fracture according to Hb. RESULTS: Compared to individuals with normal Hb, those with anemia and low normal Hb were associated with significantly increased risk of fracture. In women, those with anemia had a higher risk for any (aHR 1.11, 95% CI 1.05-1.17), hip (aHR 1.27, 95% CI 1.01-1.59), and radius fracture (aHR 1.15, 95% CI 1.05-1.25). In men, those with anemia had a higher risk for any (aHR 1.37, 95% CI 1.23-1.51), vertebral (aHR 1.33, 95% CI 1.15-1.53), and hip fracture (aHR 1.64, 95% CI 1.30-2.08). This risk-enhancing association was preserved among various subgroups. CONCLUSION: Among adults ≥ 50 years, anemia and low normal Hb are risk factors for fracture.

Association between consumption of fruits and vegetables with suicidal ideation.

OBJECTIVE: To investigate the association between fruit and vegetable (F&V) intake with suicidal ideation. DESIGN: Cross-sectional study using a Korean Community Health Survey. SETTING: F&V consumers were defined as individuals who had consumed fruits or vegetables more than once per day. Multivariable logistic regression models were used to identify factors associated with suicidal ideation including F&V consumption and to estimate the prevalence of having suicidal ideation after consideration of potential confounders. PARTICIPANTS: 221 081 Korea adults (nationally representative). RESULTS: Approximately 55 % of participants were F&V consumers. They were more likely to be young, be women, attain high educational levels, be married and be healthier physically and psychologically than the F&V non-consumers. Non-consumers had an increased risk for suicidal ideation than consumers even when potential confounders were considered, and this trend was more remarkable with vegetable intake. CONCLUSION: F&V intake is associated with low risk for suicidal ideation.

Association of tibolone and dementia risk: a cohort study using Korean claims data.

OBJECTIVE: Few studies have examined whether tibolone (TIB), a type of hormone replacement therapy widely used in Asia and Europe, affects dementia risk in postmenopausal women. Our study aims to investigate the association of TIB and dementia risk in Korean women aged 50-80 years. METHODS: A population-based longitudinal study was conducted using the Korean National Health Insurance Service claims database merged with national health examination data from 2002 to 2015. Among 13,110 participants, exposure to TIB was determined using the standardized defined daily dose (DDD) system from 2003 to 2007. Starting from 2007, participants were followed up for overall dementia, Alzheimer's disease (AD) and vascular dementia (VD) until 2015. Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) of dementia according to TIB use. RESULTS: TIB use was not significantly associated with the risk of total dementia (aHR = 1.040; 95% CI = 0.734-1.472; p = .827), AD (aHR = 0.949; 95% CI = 0.652-1.381; p = .785) and VD (aHR = 1.245; 95% CI = 0.631-2.457; p = .528). CONCLUSIONS: Our results suggest that TIB use does not have a significant association with dementia risk. Further randomized controlled trials are necessary to elucidate the role of exogenous hormones in the development of dementia.

Changes in exercise frequency and cardiovascular outcomes in older adults.

AIMS: Little is known about the association of changes in moderate to vigorous physical activity (MVPA) level with cardiovascular disease (CVD), especially in older adults whose ability to engage in frequent MVPA naturally wanes as they age. We aimed to examine the association of changes in MVPA and CVD in older adults. METHODS AND RESULTS: In a nationwide cohort study of older adults aged 60 years or older, we identified more than 1.1 million subjects without previous history of CVD at baseline who underwent two consecutive national health screening from 2009 to 2012. We prospectively assessed the risk of CVD occurred between 2013 and 2016 according to changes in frequency of MVPA by initial MVPA status. Compared to those who were continuously physically inactive, those who increased their frequency of MVPA from physically inactive to 1-2 times per week [0.7/1000 person-years (PY) decrease in incidence rate (IR); adjusted hazard ratio (aHR) 0.95; 95% confidence interval (CI) 0.92-0.99], 3-4 times per week (1.5/1000 PY decrease in IR; aHR 0.89; 95% CI 0.84-0.94), ≥5 times per week (0.4/1000 PY decrease in IR; aHR 0.91; 95% CI 0.85-0.97) had a significantly reduced risk for total CVD (P for trend <0.001). Older adults who became physically inactive from engaging in more than 1-2 times of MVPA per week had a higher CVD risk compared to those who maintained their frequency of MVPA. CONCLUSION: Among older adults, engaging in higher frequency of MVPA or maintaining MVPA level was associated with reduced risk of CVD.

Association of early-onset diabetes, prediabetes and early glycaemic recovery with the risk of all-cause and cardiovascular mortality.

AIMS/HYPOTHESIS: The increasing incidence of diabetes among young adults is a disease burden; however, the effects of early-onset diabetes, prediabetes and glycaemic recovery on CVD or mortality remain unclear. We aimed to investigate the association of these factors with 10 year all-cause mortality, CVD mortality and CVD incidence in Korean young adults. METHODS: This large and longitudinal cohort study included data from the Korean National Health Insurance Service-National Health Information Database; 2,502,375 young adults aged 20-39 years without diabetes mellitus and CVD at baseline were included. Glycaemic status was measured twice, first in 2002-2003 and second in 2004-2005. Changes in fasting glucose levels were evaluated according to fasting glucose status: normal fasting glucose (NFG; <5.5 mmol/l), impaired fasting glucose (IFG; 5.5-6.9 mmol/l), and diabetic fasting glucose (DFG; ≥7.0 mmol/l). Primary outcomes were all-cause and CVD mortality risk. The secondary outcome was incidence of CVD, including acute myocardial infarction and stroke. All outcomes arose from the 10 year follow-up period 1 Jan 2006 to 31 December 2015. RESULTS: Individuals with NFG at baseline, who were subsequently newly diagnosed with diabetes and prediabetes (IFG), had increased all-cause mortality (HR [95% CI] 1.60 [1.44, 1.78] and 1.13 [1.09, 1.18], respectively) and CVD incidence (1.13 [1.05, 1.23] and 1.04 [1.01, 1.07], respectively). In those with DFG at baseline, early recovery to NFG and IFG was associated with decreased all-cause mortality (0.57 [0.46, 0.70] and 0.65 [0.53, 0.81], respectively) and CVD incidence (0.70 [0.60, 0.81] and 0.78 [0.66, 0.91], respectively). Among patients with IFG at baseline, early recovery to NFG was associated with decreased CVD mortality (0.74 [0.59, 0.93]). CONCLUSIONS/INTERPRETATION: Early-onset diabetes or prediabetes increased CVD risks and all-cause mortality after the 10 year follow-up. Furthermore, recovery of hyperglycaemia could reduce the subsequent 10 year risk for CVD incidence and all-cause mortality. Graphical abstract.

The Association of 5α-Reductase Inhibitor With Suicidality.

OBJECTIVE: Using a large nationwide cohort, this study aimed to determine the risk of suicide after the use of a 5α-reductase inhibitor, an antiandrogenic medication commonly used in the treatment of lower urinary tract symptoms. METHODS: A retrospective population-based cohort study was performed using the Korean National Health Insurance Service database. The study consisted of 51,466 men 60 years or older who underwent health examinations between 2005 and 2006. Individuals using a 5α-reductase inhibitor were compared with nonusers based on drug exposure between 2003 and 2006. Individuals using a 5α-reductase inhibitor were additionally divided into tertiles based on cumulative 5α-reductase inhibitor exposure. The incidence of completed suicide was documented during 7 years of follow-up, starting January 1, 2007. RESULTS: No significant risk of suicide was observed among 5α-reductase inhibitor users compared with 5α-reductase inhibitor nonusers (hazard ratio = 1.02, 95% confidence interval = 0.70-1.48). Cumulative 5α-reductase inhibitor exposure was also not associated with increased risk of suicide (p for trend = .543). CONCLUSIONS: 5α-Reductase inhibitor use was not associated with an elevated risk of suicide during a long-term follow-up period. A limitation of this study is that possible drug exposure after the index date was not accounted for. Although 5α-reductase inhibitor may increase the risk of depressive symptoms, the present data indicate that the drug is safe in terms of long-term suicide risk.

Association of air pollution with osteoporotic fracture risk among women over 50 years of age.

INTRODUCTION: Air particulate matter (PM) is an environmental exposure associated with oxidation and inflammation. Whether particulate matter is associated with risk of osteoporotic bone fracture is unclear. We investigated the association between exposure to PM and risk of bone fractures. MATERIALS AND METHODS: We collected data of 44,602 participants living in three metropolitan cities in Republic of Korea from National Health Insurance Service database. We examined the association of 2 year averaged concentrations of PM and osteoporotic fracture over 4 years. Exposure to 2-year averaged air pollution [PM2.5 (< 2.5 µm in aerodynamic diameter), PM10 [< 10 µm in aerodynamic diameter], PM coarse (PM ranging from 2.5 µm to 10 µm)] concentrations were estimated from 2008 to 2009 in Air Korea data. The adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for osteoporotic fractures were calculated using the multivariate Cox proportional hazards model. RESULTS: After adjusting for age, household income, and Charlson Comorbidity Index, PM 2.5 in one pollutant model increased the risk of osteoporotic fractures, compared to the first quartile group (4th quartile group aHR = 1.13, 95% CI 1.02-1.24). Also, PM 2.5 increased the risk of spine and non-spine fractures compared to the first quartile group (4th quartile group aHR = 1.17, 95% CI 1.00-1.38, aHR = 1.16, 95% CI 1.01-1.33). We found no association between PM10/PM coarse and osteoporotic fractures. CONCLUSION: We found that PM2.5 is a risk factor for osteoporotic bone fractures.

Association between social trust and the risk of cardiovascular disease in older adults in Korea: a nationwide retrospective cohort study.

BACKGROUND: Although social capital has been shown to be one of the important social determinants of health, the association between social trust and the risk of cardiovascular disease (CVD) is not clear yet. We aimed to investigate the association of social trust with CVD risk using a large Korean population based data. METHODS: The data of this study was derived from the Korean National Health Insurance Service database. Community-level social trust was determined from the Korean Community Health Survey. The study population consisted of 2,156,829 participants. According to social trust index measured in the area of residence during 2011, participants were followed-up from 1 January 2012 to 31 December 2016. Multivariate Cox proportional hazards regression was used to determine the adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for CVD risk according to quintiles of social trust. RESULTS: Compared to participants with the lowest quintile of social trust, those within the highest quintile had lower risk for CVD (aHR 0.91, 95% CI = 0.89 to 0.93), CHD (aHR 0.92, 95% CI = 0.89 to 0.95), and stroke (aHR 0.90, 95% CI = 0.87 to 0.93). The risk-reducing association of high social trust on CVD risk was preserved after additional adjustments for lifestyle behaviors including smoking, alcohol consumption, and physical activity. CONCLUSION: Higher social trust was associated with reduced risk of CVD even after considering lifestyle behaviors. Social trust in a community level is an important determinant of CVD and enhancing social trust may lead to reduced risk of CVD.

Exposure to ambient fine particulate matter is associated with changes in fasting glucose and lipid profiles: a nationwide cohort study.

BACKGROUND: Ambient fine particulate matter is a rising concern for global public health. It was recently suggested that exposure to fine particulate matter may contribute to the development of diabetes and dyslipidaemia. This study aims to examine the potential associations of ambient particulate matter exposure with changes in fasting glucose and lipid profiles in Koreans. METHOD: We used the data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC), a nationwide database representative of the Korean population. A total of 85,869 individuals aged ≥20 years were included. Multiple regression analyses were conducted to assess the associations between exposure to particulate matter and changes in fasting glucose and lipid profiles at 2-year intervals after adjusting for confounders. RESULTS: Significant associations were observed between an increase in interquartile range for particulate matter < 2.5 µm in diameter (PM2.5) and elevated levels of fasting glucose and low-density lipoprotein cholesterol (p for trend = 0.015 and 0.010, respectively), while no association for particulate matter sized 2.5-10 µm in diameter (PM10-2.5) was noted after adjusting for the other covariates. Sub-group analyses showed stronger associations in individuals who were older (≥60 years) or physically inactive. CONCLUSIONS: Fine particulate matter exposure affects worsening fasting glucose and low-density lipoprotein cholesterol levels, with no evidence of an association for coarse particulate matter.