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.

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 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.

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.

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.

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.

The effect of change in fasting glucose on the risk of myocardial infarction, stroke, and all-cause mortality: a nationwide cohort study.

BACKGROUND: The effect of change in blood glucose levels on the risk of cardiovascular disease among individuals without diabetes is currently unclear. We aimed to examine the association of change in fasting serum glucose with incident cardiovascular disease and all-cause mortality among representative large population. METHODS: We analyzed the data from retrospective cohort of Korean National Health Insurance Service. In total, 260,487 Korean adults aged over 40 years, without diabetes mellitus and cardiovascular disease at baseline measured change in fasting serum glucose according to the criteria of impaired and diabetic fasting glucose status: normal fasting glucose (NFG, fasting glucose: < 100 mg/dL), impaired fasting glucose (IFG, fasting glucose: 100.0-125.9 mg/dL), and diabetic fasting glucose (DFG, fasting glucose: ≥ 126.0 mg/dL). Compared to the persistently unchanged group (i.e. NFG to NFG or IFG to IFG), Cox proportional hazards regression analyses were performed in the changed group to obtain the hazards ratio (HR) with 95% confidence interval (CI) for the subsequent median 8-year myocardial infarction, stroke, and all-cause mortality. RESULTS: Compared to individuals with persistent NFG (i.e., NFG to NFG), individuals who shifted from NFG to DFG had an increased risk of stroke (HR [95% CI]: 1.19 [1.02-1.38]) and individuals who shifted from NFG to IFG or DFG had increased risks of all-cause mortality (HR [95% CI]: 1.08 [1.02-1.14] for NFG to IFG and 1.56 [1.39-1.75] for NFG to DFG). Compared to individuals with persistent IFG, individuals who shifted from IFG to DFG had an increased risk of MI and all-cause mortality (HR [95% CI]: 1.65 [1.20-2.27] and 1.16 [1.02-1.33], respectively). CONCLUSIONS: Increasing fasting glucose in non-diabetic population is associated with risks of the MI, stroke, and all-cause mortality, which is more rapid, more severe.

Association of Blood Pressure Classification in Korean Young Adults According to the 2017 American College of Cardiology/American Heart Association Guidelines With Subsequent Cardiovascular Disease Events.

Importance: Among young adults, the association of the 2017 American College of Cardiology/American Heart Association (ACC/AHA) High Blood Pressure Clinical Practice Guidelines with risk of cardiovascular disease (CVD) later in life is uncertain. Objective: To determine the association of blood pressure categories before age 40 years with risk of CVD later in life. Design, Setting, and Participants: This population-based cohort study from the Korean National Health Insurance Service consisted of 2 488 101 adults aged 20 through 39 years with blood pressure measurements taken twice from 2002 through 2005. Starting from January 1, 2006, participants were followed up until the date of CVD diagnosis, death, or December 31, 2015. Exposures: Participants were categorized by blood pressure readings: normal (systolic, <120 mm Hg; diastolic, <80 mm Hg), elevated (sytolic, 120-129 mm Hg; diastolic, <80 mm Hg), stage 1 hypertension (systolic, 130-139 mm Hg; diastolic, 80-89 mm Hg), and stage 2 hypertension (systolic, ≥140 mm Hg; diastolic, ≥90 mm Hg). Main Outcomes and Measures: The primary outcome was CVD defined as 2 or more days of hospitalization due to CVD or death due to CVD. The secondary outcomes were coronary heart disease (CHD) and stroke. Results: The study population consisted of 2 488 101 participants (median age, 31 years [interquartile range, 27-36 years], 789 870 women [31.7%]). A total of 44 813 CVD events were observed during a median follow-up duration of 10 years. Men with baseline stage 1 hypertension compared with those with normal blood pressure had higher risk of CVD (incidence, 215 vs 164 per 100 000 person-years; difference, 51 per 100 000 person-years [95% CI, 48-55]; adjusted hazard ratio [HR], 1.25 [95% CI, 1.21-1.28]), CHD (incidence, 134 vs 103 per 100 000 person-years; difference, 31 per 100 000 person-years [95% CI, 28-33]; adjusted HR, 1.23 [95% CI, 1.19-1.27]), and stroke (incidence, 90 vs 67 per 100 000 person-years; difference, 23 per 100 000 person-years [95% CI, 21-26]; adjusted HR, 1.30 [95% CI, 1.25-1.36]). Women with baseline stage 1 hypertension compared with those with normal blood pressure had increased risk of CVD (incidence, 131 vs 91 per 100 000 person-years; difference, 40 per 100 000 person-years [95% CI, 35-45]; adjusted HR, 1.27 [95% CI, 1.21-1.34]), CHD (incidence, 56 vs 42 per 100 000 person-years; difference, 14 per 100 000 person-years [95% CI, 11-18]; adjusted HR, 1.16 [95% CI, 1.08-1.25]), and stroke (incidence, 79 vs 51 per 100 000 person-years; difference, 28 per 100 000 person-years [95% CI, 24-32]; adjusted HR [1.37, 95% CI, 1.29-1.46]). Results for state 2 hypertension were consistent. Conclusions and Relevance: Among Korean young adults, stage 1 and stage 2 hypertension, compared with normal blood pressure, were associated with increased risk of subsequent cardiovascular disease events. Young adults with hypertension, defined by the 2017 ACC/AHA criteria, may be at increased risk of cardiovascular disease.

Comparative Effect of Glucose-Lowering Drugs for Type 2 Diabetes Mellitus on Stroke Prevention: A Systematic Review and Network Meta-Analysis.

BACKGRUOUND: There is still a lack of research on which diabetic drugs are more effective in preventing stroke. Our network metaanalysis aimed to compare cerebrovascular benefits among glucose-lowering treatments. METHODS: We searched MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and the ClinicalTrials.gov registry for clinical trials from inception through May 25, 2021. We included both prespecified cerebrovascular outcomes and cerebrovascular events reported as severe adverse events. Subgroup analyses were conducted by stroke subtype, publication type, age of patients, baseline glycosylated hemoglobin (HbA1c), duration of type 2 diabetes mellitus, and cardiovascular risks. RESULTS: Of 2,861 reports and 1,779 trials screened, 79 randomized controlled trials comprising 206,387 patients fulfilled the inclusion criteria. In the pairwise meta-analysis, the use of glucagon-like peptide-1 (GLP-1) agonist was associated with a lower risk of total stroke compared with placebo (relative risk [RR], -0.17; 95% confidence interval [CI], -0.27 to -0.07). In the network meta- analysis, only the use of sodium-glucose cotransporter-2 (SGLT-2) inhibitor was associated with a reduction of total stroke, compared with placebo (RR, 0.81; 95% CI, 0.67 to 0.98). In the subgroup analyses, the use of SGLT-2 inhibitor and GLP-1 agonist was associated with a lower risk of stroke in those with high HbA1c (≥8.0) and low-risk of cardiovascular disease, respectively. CONCLUSION: SGLT-2 inhibitors and GLP-1 agonists were shown to be beneficial for stroke prevention in patients with type 2 diabetes mellitus.

Association of changes in predicted body composition with subsequent risk of dementia.

OBJECTIVE: The effect of body composition change on the risk of dementia is not clear. This study analyzed the associations of changes in predicted lean body mass index (pLBMI), predicted appendicular skeletal muscle mass index (pASMI), and predicted body fat mass index (pBFMI) with the risk of dementia. METHODS: In this nationwide cohort study, data were obtained from the Korean National Health Insurance Service database. The exposure was defined as changes in pLBMI, pASMI, and pBFMI derived from validated prediction equations. The outcome was dementia, defined based on the dementia diagnosis with prescription of anti-dementia medication. Cox proportional hazards regression analyses were performed to obtain the hazard ratio with a 95% confidence interval for risk of dementia according to changes in predicted body composition. RESULTS: A total of 13,215,208 individuals with no prior record of dementia who underwent health screenings twice between 2009-2010 and 2011-2012 were included. A 1-kg/m2 increase in pLBMI and pASMI had an association with reduced risk of dementia (aHR: 0.85, 95% CI 0.84-0.87; aHR: 0.70, 95% CI 0.69-0.72, respectively for men, and aHR: 0.69, 95% CI 0.67-0.71; aHR: 0.59, 95% CI 0.57-0.61, respectively for women). A 1-kg/m2 increase in pBFMI had an association with a raised risk of dementia (aHR: 1.19, 95% CI 1.17-1.21 for men and aHR: 1.53, 95% CI 1.48-1.57 for women). These results remained consistent regardless of sex or weight change. INTERPRETATION: Increase in pLBMI or pASMI, or reduction in pBFMI was linked to lower risk of dementia.

Cardiovascular Benefit of Statin Use Against Air Pollutant Exposure in Older Adults.

BACKGROUND AND AIMS: Little is known about the cardiovascular benefit of statin use against ambient air pollution among older adults who are at higher risk of cardiovascular disease (CVD) potentially owing to age-related declines in cardiovascular functions along with other risk factors. METHODS AND RESULTS: This retrospective, population-based cohort study consisted of adults aged 60 years and older free of CVD at baseline identified from the National Health Insurance Service (NHIS) database linked to the National Ambient Air Monitoring Information System (NAMIS) for average daily exposure to PM10 and PM2.5 in 2015 in the major metropolitan areas in the Republic of Korea. Follow-up period began on January 1, 2016 and lasted until December 31, 2021. Cox proportional hazards model was used to evaluate association of cardiovascular benefit with statin use against different levels of air pollutant exposure. Of 1,229,444 participants aged 60 years and older (mean age, 67.4; 37.7% male), 377,076 (30.7%) were identified as statin-users. During 11,963,322 person-years (PY) of follow-up, a total of 86,018 incident stroke events occurred (719.0 events per 100,000 PYs). Compared to statin non-user exposed to high level of PM10 (>50 µg/m3) and PM2.5 (>25 µg/m3), statin users had 20% (adjusted hazard ratio [HR], 0.80; 95% confidence intervals [CI], 0.75 to 0.85) and 17% (adjusted HR, 0.80; 95% CI, 0.80 to 0.86) lower adjusted risk of incident stroke for PM10 and PM2.5, respectively. Similar risk reduction for incident CVD was also found among statin-users exposed to low or moderate level of PM10 (≤50 µg/m3) and PM2.5 (≤25 µg/m3) exposure. CONCLUSION: Among adults aged 60 years and older with high and low or moderate levels of exposure to PM10 and PM2.5, statin use was associated with a significantly lower risk of stroke.

In a retrospective cohort study of older adults exposed to high and low or moderate levels of PM10 and PM2.5, statin use was associated with a significantly lower risk of incident stroke.

Antibiotic exposure and depression incidence: A cohort study of the Korean population.

Recent research highlights the crucial role of the gut-brain axis in understanding depression etiologies. While burgeoning studies suggest an association between disruptions in gut microbiota and the development of depression, limited longitudinal studies have investigated this link. To address this gap, we conducted a retrospective cohort study using National Health Insurance Service-Health Screening Cohort (NHIS-HEALS) data in South Korea, involving 199,144 individuals aged 40-79. We examined the impact of cumulative antibiotic exposure (2004-2008) on subsequent depression incidence (2009-2013) by conducting Cox proportional hazards regressions. Our findings show an increasing depression risk with extended antibiotic exposure after adjusting for comorbidities and behavioral covariates. A broader antibiotic spectrum was associated with a higher depression risk. These trends persisted after adjusting for the original antibiotic indications. In conclusion, our study highlights the duration-dependent association between antibiotic exposure and increased depression risk, offering insights into depression etiologies and relevant novel therapeutic tools, and advocating for heightened antibiotic stewardship considering their impact on mental health.

Evolutionary changes in metabolic dysfunction-associated steatotic liver disease and risk of hepatocellular carcinoma: A nationwide cohort study.

BACKGROUND/AIMS: To determine the association between evolutionary changes in metabolic dysfunction-associated steatotic liver disease (MASLD) status and the risk of hepatocellular carcinoma (HCC) in a nationwide population-based cohort. METHODS: Information on study participants was derived from the Korea National Health Insurance Service database. The study population consisted of 5,080,410 participants who underwent two consecutive biennial health screenings between 2009 and 2012. All participants were followed up until HCC, death, or 31 December 2020. The association of evolutionary changes in MASLD status, as assessed by the fatty liver index and cardiometabolic risk factors, including persistent non-MASLD, resolved MASLD, incident MASLD, and persistent MASLD, with HCC risk was evaluated using multivariable-adjusted Cox proportional hazards regression. RESULTS: Among the 5,080,410 participants with 39,910,331 person-years of follow-up, 4,801 participants developed HCC. The incidence of HCC in participants with resolved, incident, and persistent MASLD was approximately 2.2-, 2.3-, and 4.7-fold higher, respectively, than that in those with persistent non-MASLD among the Korean adult population. When stratifying the participants according to the evolutionary change in MASLD status, persistent (adjusted hazard ratio [aHR], 2.94; 95% confidence interval [CI], 2.68-3.21; P<0.001), incident (aHR, 1.85; 95% CI, 1.63-2.10; P<0.001), and resolved MASLD (aHR, 1.33; 95% CI, 1.18-1.50; P<0.001) had an increased risk of HCC compared to persistent non-MASLD. CONCLUSION: The evolutionary changes in MASLD were associated with the differential risk of HCC independent of metabolic risk factors and concomitant medications, providing additional information on the risk of HCC stratification in patients with MASLD.

Association of hemoglobin variability with the risk of cardiovascular disease: a nationally representative retrospective cohort study from South Korea.

Hemoglobin variability is known to increase cardiovascular mortality in chronic kidney disease, but the association of hemoglobin variability with the risk of cardiovascular disease (CVD) in the general population is yet unclear. This retrospective cohort study based on 'the South Korean National Health Insurance Service database' consisted of 198,347 adults who went through all three health examinations. Hemoglobin variability is defined as the average successive variability of three separate hemoglobin values from each health screening period. Participants were followed up for 6 years to determine the risk of coronary heart disease and stroke. We used multivariate Cox proportional hazards regression to examine the adjusted hazard ratios for CVD according to hemoglobin variability. Per 1 unit increase of hemoglobin variability, the risk for CVD (aHR 1.06, 95% CI 1.02-1.09) and stroke (aHR 1.08, 95% CI 1.03-1.13) increased significantly. The risk-increasing trend was preserved in the low-to-moderate risk group of CVDs (aHR 1.07, 95% CI 1.02-1.11). This result suggests that subjects with high hemoglobin variability who would otherwise be categorized as having low-to-moderate CVD risk may have higher risk of CVD than those with low hemoglobin variability.

Association of Thyroid Hormone Medication Adherence With Risk of Dementia.

CONTEXT: Recent studies suggest that hypothyroidism is a risk factor for dementia. Based on existing literature, it is unclear if treatment or compliance to treatment is associated with decreased dementia risk in hypothyroidism patients. OBJECTIVE: To determine the association between thyroid hormone medication adherence and risk of dementia. METHODS: A population-based cohort study following patients with newly diagnosed hypothyroidism until incidence of dementia, death, or December 31, 2020, whichever came earliest. The study comprised 41 554 older adults age 50 and above with newly diagnosed hypothyroidism between 2004 and 2008 who underwent health screening. Risk of dementia was evaluated using multivariable-adjusted Cox proportional hazards regression. RESULTS: Among 5188 men (12.5%) and 36 366 (87.5%) women, 2120 cases of incident dementia were identified. After stratification of the participants according to the interquartile range of the medication possession ratio (MPR), the fourth quartile (highest adherence) showed a 14% lower risk of overall dementia compared with the first quartile (lowest adherence) (adjusted hazard ratio 0.86; 95% CI 0.76-0.97). No consistent association was observed between thyroid hormone medication adherence and vascular dementia. After a dichotomous stratification of the MPR, higher MPR (≥0.8) showed a lower risk of Alzheimer disease (adjusted hazard ratio 0.91; 95% CI 0.84-0.99) than lower MPR (<0.8). CONCLUSION: Better adherence to thyroid hormone medication may be beneficial in preventing incident dementia, especially Alzheimer disease, in older adults with newly diagnosed hypothyroidism. Along with the resolution of hypothyroid symptoms and the reduction of cardiovascular risk factors, the reduction of dementia risk may be another potential benefit of thyroid hormone medication.

Changes in total cholesterol level and cardiovascular disease risk among type 2 diabetes patients.

Despite many diabetic patients having hypercholesterolemia, the association of total cholesterol (TC) levels with CVD risk in type 2 diabetes (T2D) patients is unclear. Diagnosis of type 2 diabetes often leads to changes in total cholesterol (TC) levels. Thus, we examined whether changes in TC levels from pre- to post-diagnosis of T2D were associated with CVD risk. From the National Health Insurance Service Cohort, 23,821 individuals diagnosed with T2D from 2003 to 2012 were followed-up for non-fatal CVD incidence through 2015. Two measurements of TC, 2 years before and after T2D diagnosis, were classified into 3 levels (low, middle, high) to define changes in cholesterol levels. Cox proportional hazards regression was performed to estimate adjusted hazards ratios (aHRs) and 95% confidence intervals (CIs) for the associations between changes in cholesterol levels and CVD risk. Subgroup analyses were performed by use of lipid-lowering drugs. Compared with low-low, aHR of CVD was 1.31 [1.10-1.56] for low-middle and 1.80 [1.15-2.83] for low-high. Compared with middle-middle, aHR of CVD was 1.10 [0.92-1.31] for middle-high but 0.83 [0.73-0.94] for middle-low. Compared with high-high, aHR of CVD was 0.68 [0.56-0.83] for high-middle and 0.65 [0.49-0.86] for high-low. The associations were observed regardless of use of lipid-lowering drugs. For diabetic patients, management of TC levels may be important to lower CVD risk.

Association of the amount of alcohol consumption with change in skeletal muscle and fat mass among Korean adults.

The association between changes in alcohol consumption and body composition remains unclear. We investigated the association between changes in drinking habits and muscle mass and fat mass in adults. From the Health Examinees in Korea, the study population (N = 62 094) was categorized according to alcohol consumption (g of ethanol/day) and the changes in drinking habits between the baseline and follow-up periods were determined. Predicted muscle mass index (pMM), lean mass index, and fat mass index (pFM) were also calculated using age, sex, weight, height, and waist circumference. The ß coefficient and adjusted means were then calculated using multiple linear regression analysis after adjusting for covariates, including follow-up duration, calorie intake, and protein intake. Compared to the almost-unchanged drinking group (reference; adjusted mean: -0.030 [95% confidence intervals: -0.048, -0.011]), there was no statistical difference or tendency of change in the pMMs of the most-decreased (-0.024 [-0.048, 0.000]) and the most-increased (-0.027 [-0.059, -0.013]) alcohol-consumed groups. The pFM decreased at those with less alcohol consumption (0.053 [-0.011, 0.119]) and increased with increased alcohol consumption (0.125 [0.063, 0.187]), compared to the no-change group (reference; 0.088 [0.036, 0.140]). Thus, changes in alcohol consumption were not significantly associated with changes in muscle mass. Increased alcohol consumption was associated with increased fat mass. Reducing the amount of alcohol consumption may improve body composition in terms of fat mass.