Fatty Liver & Diabetes Statistics in Korea: Nationwide Data 2009 to 2017

BACKGROUND

This study investigated the changes of fatty liver disease prevalence in general Korean population.

METHODS

This study analyzed data from the Korean National Health Insurance Service from 2009 to 2017 that included individuals aged 20 years or older who had undergone a medical health examination. Fatty liver disease was assessed using the fatty liver index (FLI). The disease severity was defined by FLI cutoff, ≥30 as moderate, and ≥60 as severe fatty liver disease.

RESULTS

The prevalence of Korean adults aged 20 years or over with fatty liver disease (FLI ≥60) increased from 13.3% in 2009 to 15.5% in 2017 (P for trend <0.001). The increase in fatty liver disease prevalence was prominent in men (from 20.5% to 24.2%) and the young age (20 to 39 years) group (from 12.8% to 16.4%) (P for interaction <0.001). The prevalence of fatty liver disease was the highest in type 2 diabetes mellitus (T2DM, 29.6%) population compared to that of prediabetes or normoglycemia (10.0% and 21.8%) in 2017. The prevalence of fatty liver disease had statistically increased in individuals with T2DM and prediabetes (P for trend <0.001). Its prevalence increased more steeply in the young-aged population with T2DM, from 42.2% in 2009 to 60.1% in 2017. When applying a lower FLI cutoff (≥30) similar results were observed.

CONCLUSION

The prevalence of fatty liver disease in the Korean population has increased. Individuals who are young, male, and have T2DM are vulnerable to fatty liver disease.

Association between glycemic status and age-related macular degeneration: A nationwide population-based cohort study

AIM

The risk of dry and wet age-related macular degeneration (AMD) based on fasting glucose levels and disease duration of type 2 diabetes was investigated.

METHODS

Using a health insurance claims database and the results of health examinations in South Korea, we conducted a retrospective, population-based cohort study of 2,103,604 adults ≥ 45 years of age who were AMD-free based on health checkups in 2009 and observed from January 1, 2011, to December 31, 2018. Glycemic status was classified into five groups: normal, impaired fasting glucose, new-onset diabetes (fasting glucose level ≥ 126 mg/dl but no diabetes diagnosis or diabetes medication), diabetes diagnosis < 5 years, and diabetes ≥ 5 years. According to the presence and absence of choroidal neovascularization, AMD was classified as wet AMD and dry AMD, respectively. Adjusted hazard ratios (HRs) of AMD occurrence were estimated in each category.

RESULTS

For dry AMD (n = 36,271, 1.72%), the HR was 1.192 (1.141-1.245) among subjects with diabetes < 5 years and 1.294 (1.242-1.349) among subjects with diabetes ≥ 5 years compared with subjects with normal glycemic status after adjusting for age, sex, body mass index, lifestyle, and medical history. For wet AMD (n = 12,912, 0.61%), the HR was 1.103 (1.011-1.203) among subjects with new-onset diabetes, 1.252 (1.167-1.344) among subjects with diabetes < 5 years, and 1.506 (1.413-1.605) among subjects with diabetes ≥ 5 years. The HR of AMD was significantly increased among participants ≤ 65 years old and those who did not have hypertension.

CONCLUSIONS

The incidence of dry and wet AMD increased among diabetes patients compared to the normal glycemic status group. These risks increased when the duration of diabetes was 5 years or more. The risk of wet AMD was increased among new-onset diabetes patients. These results suggest that high blood glucose levels without treatment might induce the vision-threatening condition of wet AMD, emphasizing the importance of early blood glucose management.

Insulin Fact Sheet in Type 1 and 2 Diabetes Mellitus and Trends of Antidiabetic Medication Use in Insulin Users with Type 2 Diabetes Mellitus: 2002 to 2019

BACKGROUND

This study investigated the trends of insulin use among Korean patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Changes in prescription of antidiabetic medications in T2DM patients taking insulin therapy were evaluated.

METHODS

We analyzed data from the National Health Insurance Service database in Korea to evaluate the prevalence of insulin users and trends of insulin use in T1DM and T2DM patients from January 2002 to December 2019. We also investigated numbers and types of antidiabetic medications in insulin users with T2DM.

RESULTS

The overall total number of insulin users increased from 2002 to 2019, reaching 348,254 for T2DM and 20,287 for T1DM in 2019 compared with 109,974 for T2DM and 34,972 for T1DM in 2002. The proportion of patients using basal analogs and short acting analogs have increased and those using human insulin, premixed insulin, or biphasic human insulin have decreased (rapid acting analogs: 71.85% and 24.12% in T1DM and T2DM, respectively, in 2019; basal analogs: 76.75% and 75.09% in T1DM and T2DM, respectively, in 2019). The use of other antidiabetic medication in addition to insulin increased for T2DM, especially in dual therapy, reaching up to 52.35% in 2019 compared with 16.72% in 2002.

CONCLUSION

The proportion of the patients using basal or rapid acting analogs increased among all insulin users in both T1DM and T2DM patients. Among patients with T2DM, the proportion of patients using antidiabetic medications in addition to insulin was significantly increased compared to those who used insulin alone.

Increased risk of incident atrial fibrillation in young adults with mental disorders: A nationwide population-based study

BACKGROUND

Mental disorders and cardiovascular diseases are closely related. However, a paucity of information on the risk of incident atrial fibrillation (AF) in patients with mental disorders exists.

OBJECTIVE

We aimed to assess the association between mental disorders and the risk of AF, particularly in young adults.

METHODS

Using the Korean National Health Insurance Database between 2009 and 2012, we identified adults aged 20-39 years without a history of AF and who have been diagnosed with mental disorders. Mental disorders were defined as having one of the following diagnoses: depression, insomnia, anxiety disorder, bipolar disorder, or schizophrenia. The primary outcome was new-onset AF during follow-up.

RESULTS

A total of 6,576,582 subjects (mean age 30.9 ± 5.0 years; 3,919,339 [59.6%] men) were included. Among the total population, 10% had mental disorders. During the follow-up period, 8932 incident AF events occurred. Patients with mental disorders showed a higher AF incidence than did those without (25.4 per 100,000 person-years vs 17.7 per 100,000 person-years). After multivariable adjustment, mental disorders were associated with a significantly higher risk of AF (adjusted hazard ratio 1.526; 95% confidence interval 1.436-1.621). Patients with bipolar disorder or schizophrenia had a 2-fold higher risk of AF and those with depression, insomnia, and anxiety disorder had a 1.5- to 1.7-fold higher risk of AF than did those without mental disorders.

CONCLUSION

Young adults diagnosed with mental disorders have a higher risk of incident AF. Awareness for AF in high-risk populations should thus be considered.

Risk of fracture in neuromyelitis optica spectrum disorder and multiple sclerosis: a nationwide cohort study in South Korea

PURPOSE

Interest in fractures in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) has considerably increased in the last decade. However, few studies have compared the incidence of fractures between patients with MS and NMOSD using a nationwide database. This study aimed to evaluate the differences in the risk of fracture between patients with NMOSD and MS compared to that in healthy controls using cohort data from a Korean nationwide database.

METHODS

In this retrospective cohort study, data from the National Health Insurance Service (NHIS) database from January 2010 to December 2017 were analyzed. A total of 1,217/1,329 patients with MS/NMOSD free of fractures at the index date were included. Matched controls were selected based on age, sex, and the presence of hypertension, diabetes mellitus, and dyslipidemia. The mean follow-up durations after the index date were 4.40/4.08 years for patients with MS/NMOSD and 4.73/4.28 for their matched controls.

RESULTS

The adjusted hazard ratios (aHRs) with 95% confidence intervals of any, hip, and vertebral fractures were 1.81 (1.43-2.28), 3.36 (1.81-6.24), and 2.01 (1.42-2.99) times higher for patients with MS than for controls, respectively, and they were 1.85 (1.47-2.34), 3.82 (2.05-7.11), and 2.84 (1.92-4.21) times higher for patients with NMOSD than for controls, respectively. No significant differences were observed in the incidence of fractures between the MS and NMOSD groups. Patients with MS/NMOSD had a 1.8-fold higher risk of fracture than matched controls, and the risk of hip fracture was especially high (3- to 4-fold higher).

CONCLUSIONS

Clinicians need to regularly assess patients with MS/NMOSD for the risk of fractures and take preventative measures to reduce it.

Association between low-density lipoprotein cholesterol and sudden cardiac arrest in people with diabetes mellitus

BACKGROUND

Dyslipidemia measured as low-density lipoprotein (LDL)-cholesterol is an established risk factor of cardiovascular disease, which is more pronounced in diabetes population. Less is known about the association of LDL-cholesterol level and sudden cardiac arrest (SCA) risk in diabetes mellitus patients. This study investigated the association of LDL-cholesterol level and SCA risk in diabetes population.

METHODS

This study was based on Korean National Health Insurance Service database. Patients who received general examination from 2009 to 2012 and diagnosed as type 2 diabetes mellitus were analyzed. Primary outcome was defined as SCA event identified with International Classification of Disease code.

RESULTS

A total of 2,602,577 patients were included, with total follow-up duration of 17,851,797 person * year. Mean follow-up duration was 6.86 years, and 26,341 SCA cases were identified. Overall incidence of SCA was highest in the lowest LDL-cholesterol group (< 70 mg/dL) and decreased in a linear manner as LDL-cholesterol rises, till 160 mg/dL. Adjustment of covariates resulted in U-shape association, with highest risk of SCA in the highest LDL-cholesterol group (≥ 160 mg/dL) followed by lowest LDL-cholesterol group (< 70 mg/dL). In subgroup analysis, U-shape association between SCA risk and LDL-cholesterol was more pronounced in male, non-obese people, and those who did not use statins.

CONCLUSIONS

In people with diabetes, the association between SCA and LDL-cholesterol level was U-shaped with highest and lowest LDL-cholesterol group having higher risk of SCA than others. Low LDL-cholesterol level can be a surrogate marker for increased risk of SCA in people with diabetes mellitus and this paradoxical association should be recognized and extended to clinical preventive measures.

Rheumatoid arthritis and the risk of end-stage renal disease: A nationwide, population-based study

Introduction

Despite the risk of incident chronic kidney disease among the patients with rheumatoid arthritis (RA), the association of RA and the risk of end-stage renal disease (ESRD) has not been clearly elucidated. We aimed to investigate the association of RA and the risk of ESRD.

Materials and methods

A total of 929,982 subjects with (n = 154,997) or without (n = 774,985) RA from the National Health Insurance Service (NHIS) database in Koreas (corresponding to the period between 2009 and 2017) were retrospectively analyzed. RA was defined by the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM), codes plus any dispensing of disease-modifying anti-rheumatic drugs. The primary outcome was incident ESRD, identified by a combination of the ICD-10-CM codes and a special code assigned to patients receiving maintenance dialysis for ≥ 3 months or those with a transplant kidney.

Results

Compared to the subjects without RA, the subjects with RA resulted in an increased incidence of ESRD (incidence rates of 0.374 versus 0.810 cases per 1,000 person-years). Accordingly, compared to the subjects without RA, the risk of ESRD was significantly increased among the subjects with RA (adjusted hazard ratio 2.095, 95% confidence interval 1.902-2.308). Subgroup analyses revealed that the risk of ESRD imposed by RA is relatively higher in relatively young and healthy individuals.

Conclusion

Rheumatoid arthritis (RA) increase the risk of ESRD. As the risk of ESRD imposed by RA is relatively higher in relatively young and healthy individuals, kidney-protective treatment, such as biologic agents, should be preferentially considered among these patients with RA.

Early Rhythm Control in Patients With Incident Atrial Fibrillation Who Had a Prior Stroke

BACKGROUND

There are limited data regarding the benefit of early rhythm control therapy for secondary prevention for stroke in patients with atrial fibrillation (AF).

OBJECTIVES

This study aimed to compare the risk of recurrent stroke between early rhythm control therapy and usual care in patients with new-onset AF and a history of prior stroke.

METHODS

Using the Korean nationwide claims database, the investigators identified patients who were newly diagnosed with AF and had a history of prior stroke. Patients who received rhythm control therapy, including antiarrhythmic drug, direct current cardioversion, or AF catheter ablation, within 1 year after incident AF were defined as the early rhythm control group, and the others were the usual care group. The propensity score weighting method was used to balance baseline characteristics between the 2 groups. Incident stroke was evaluated as a primary outcome.

RESULTS

A total of 53,509 patients were included (12,455 in the early rhythm control group and 41,054 in the usual care group). All patients were prescribed oral anticoagulants. During a median 2.6 years of follow-up, 4,382 patients had an incident stroke (incidence rate: 2.6 per 100 person-years). Early rhythm control was associated with a lower risk of recurrent stroke compared to the risk associated with usual care (weighted HR: 0.720; 95% CI: 0.666-0.779; P < 0.001).

CONCLUSIONS

Early rhythm control within 1 year after AF diagnosis might be beneficial to prevent recurrent stroke in patients with incident AF and a history of stroke. Integrated care, including optimal rhythm control with appropriate anticoagulation, should be considered in this population.

The beneficial effects of an adenotonsillectomy upon upper respiratory tract infections, asthma and rhinitis in children: a national database study in Korea

BACKGROUND

Adenotonsillectomy is the most commonly performed surgery in children.

AIMS

To evaluate the effects of pediatric adenotonsillectomy on health care utilization.

METHODS

From 2006 to 2017, age/sex-matched adenotonsillectomy participants (n = 243.396) and controls (n = 730.188) were selected (62% of male and 38% of female. 47% age≦ 6, 16% 7-9years, 8% 10-12years, 29% 13-18years). The changes in outpatient visits, hospitalization days, and drug prescriptions due to a URI, asthma, and rhinitis before and after the surgery date (from 13 months to 1 month) were compared.

RESULTS

Outpatient visits decreased more in the surgery group than the control group (mean change, 3.24 ± 8.61 d and 1.16 ± 6.57 d for URI, 2.07 ± 8.63 d and 0.51 ± 6.47 d for rhinitis, and 0.72 ± 4.81 d and 0.42 ± 3.91 d for asthma, p < .001 for all). Hospitalizations also showed greater decreases in the surgery group (mean change, 0.31 ± 2.96 d and 0.04 ± 1.70 d for URI, 0.13 ± 2.40 d and 0.02 ± 1.48 d for rhinitis, 0.11 ± 2.32 d and 0.04 ± 1.83 d for asthma, p < .001 for all). The prescription of antihistamines, leukotriene modulators, oral antibiotics, oral steroids, and expectorants, cough suppressants and oral bronchodilators was also decreased after surgery.

CONCLUSIONS

The adenotonsillectomy group showed a greater decrease in post-operative outpatients visits, hospital days and drug prescriptions associated with URI, rhinitis and asthma than the control group.

Remnant Cholesterol Is an Independent Predictor of Type 2 Diabetes: A Nationwide Population-Based Cohort Study

OBJECTIVE

Although the atherogenic effect of remnant cholesterol (remnant-C) has been widely recognized, the relationship between remnant-C and glucose metabolism remains unclear. This retrospective, longitudinal study investigated the relationship between remnant-C and incident type 2 diabetes (T2D) in a nationwide cohort of Korean adults.

RESEARCH DESIGN AND METHODS

A total of 8,485,539 Korean adults without diabetes participated in the national health screening in 2009 and were followed up until 2019. The relationship between remnant-C quartiles and incident T2D was examined by Cox regression models. The risk of incident T2D over the continuum of remnant-C was examined with cubic spline analysis.

RESULTS

During the median follow-up period of 9.28 years, 584,649 individuals (6.8%) developed T2D. In multivariable-adjusted analyses, participants in the upper quartile of remnant-C had a higher risk of T2D, with hazard ratios of 1.25 (95% CI 1.24-1.27) in the second quartile, 1.51 (95% CI 1.50-1.53) in the third quartile, and 1.95 (95% CI 1.93-1.97) in the fourth quartile, compared with the lowest quartile. The increase in the risk of T2D owing to high remnant-C concentration was more profound in individuals with fewer traditional T2D risks, such as women, and absence of metabolic abnormalities, including impaired fasting glucose, hypertension, and atherogenic dyslipidemia. Moreover, the magnitude of the increased risk for incident T2D in individuals with higher remnant-C quartiles was higher in younger participants than older participants.

CONCLUSIONS

These findings indicate that remnant-C profiles provide additional information in predicting future progression of T2D, independent of the conventional lipid parameters.

Being Underweight Is Associated with Increased Risk of Sudden Cardiac Death in People with Diabetes Mellitus

BACKGROUND

Diabetes mellitus (DM) can cause various atherosclerotic cardiovascular disease including sudden cardiac death (SCD). The impact of being underweight on the risk of SCD in people with DM remains to be revealed. We aimed to evaluate the risk of SCD according to body-mass index (BMI; kg/m²) level in DM population.

METHODS

We used a nationwide healthcare insurance database to conduct this study. We identified people with DM among those who underwent nationwide health screening during 2009 to 2012. Medical follow-up data was available until December 2018.

RESULTS

A total of 2,602,577 people with DM with a 17,851,797 person*year follow-up were analyzed. The underweight group (BMI < 18.5) showed 2.4-fold increased risk of SCD during follow-up (adjusted-hazard ratio [HR] = 2.40; 95% confidence interval [CI] = 2.26-2.56; p < 0.001). When normal-BMI group (18.5 ≤ BMI < 23) was set as a reference, underweight group (adjusted-HR = 2.01; 95% CI = 1.88-2.14) showed even higher risk of SCD compared with the obesity group (BMI ≥ 30; adjusted-HR = 0.89; 95% CI = 0.84-0.94). When BMI was stratified by one unit, BMI and SCD risk showed a U-curve association with the highest risk observed at low BMI levels. The lowest risk was observed in 27 ≤ BMI < 28 group. The association between being underweight and increased SCD risk in DM people was maintained throughout various subgroups.

CONCLUSIONS

Being underweight is significantly associated with an increased risk of SCD in the DM population. A steep rise in the risk of SCD was observed as the BMI level decreased below 23. The lowest risk of SCD was observed in 27 ≤ BMI < 28 group.

Hormone Replacement Therapy and the Incidence of Nonarteritic Anterior Ischemic Optic Neuropathy: a Nationwide Population-Based Study (2009-2018)

PURPOSE

This study aimed to assess the association between hormone replacement therapy (HRT) and the prevalence of nonarteritic anterior ischemic optic neuropathy (NAION) in menopausal women using national data from the entire Korean population.

METHODS

The health screening data of 1,381,605 women between 40 and 90 years of age collected by the National Health Insurance Service (NHIS) of Korea between January 1, 2009, and December 31, 2018, were retrospectively reviewed. Before data analysis, the potential cofounders were adjusted for among all participants. Based on HRT use and its duration (classified into four groups), the hazard ratio (HR) and 95% confidence interval (CI) of NAION development were calculated via a Cox proportional hazards regression analysis using the nonuser group as a reference.

RESULTS

Overall, 7824 NAION diagnoses were made during the mean follow-up of 8.22 years (standard deviation: 1.09 years) in 1,381,605 post-menopausal women. NAION was more common in the HRT group than in the non-HRT group (HR [95% CI]: 1.268 [1.197-1.344]). Furthermore, the risk of NAION increased along with increased HRT duration (p < 0.0001). In the multivariate analysis, the adjusted HRs of the < 2-year HRT group, the 2-5-year HRT group, and the ≥ 5-year HRT group were 1.19 (95% CI: 1.10-1.28), 1.3 (95% CI: 1.17-1.45), and 1.473 (95% CI: 1.31-1.65), respectively. Compared to women younger than 65 years, the HR of HRT for NAION was significantly higher than that of women older than 65 years (p < 0.0001).

CONCLUSION

Our population-based cohort study found that HRT was significantly associated with increased incidence of NAION. The incidence of NAION also increased with the duration of HRT.

Blood pressure status affects atrial fibrillation in diabetic end-stage renal disease

INTRODUCTION

The prevalence of atrial fibrillation (AF) is increasing as the elderly population continues to increase. Chronic kidney disease, diabetes, and hypertension are known risk factors for AF. Since multimorbidity exists in chronic kidney disease, it is difficult to determine the impact of hypertension alone. Furthermore, little is known about the impact of hypertension on predicting AF in diabetic end-stage renal disease (ESRD). Here, we evaluated the effect of differential blood pressure control on AF prevalence among the diabetic ESRD population.

METHODS

From the Korean National Health Insurance Service database, 2 717 072 individuals with diabetes underwent health examinations during 2005-2019. Exactly 13 859 individuals with diabetic ESRD without a prior history of AF were selected and included in the analysis. Based on blood pressure level and previous hypertension medication history, we subdivided them into five groups: normal (normotensive), pre-hypertension, new onset hypertension, controlled hypertension, and uncontrolled hypertension. AF risk according to the blood pressure groups was estimated using Cox proportional-hazards models.

RESULTS

Among the five groups, the new onset hypertension, controlled hypertension, and uncontrolled hypertension groups showed a higher AF risk. In patients on antihypertensives, diastolic blood pressure ≥100 mmHg was significantly associated with AF risk. High pulse pressure showed a significant risk for AF in patients on antihypertensives.

CONCLUSION

In patients with diabetic ESRD, overt hypertension and a history of hypertension impacts AF. AF risk was higher in the ESRD population with diastolic blood pressure ≥100 mmHg and pulse pressure >60 mmHg.

Cardiovascular Outcomes according to Comorbidities and Low-Density Lipoprotein Cholesterol in Korean People with Type 2 Diabetes Mellitus

BACKGROUND

There are no clear data to support the cardiovascular (CV) risk categories and low-density lipoprotein cholesterol (LDL-C) treatment goals in Korean people with type 2 diabetes mellitus (T2DM). We evaluated the incidence of cardiovascular disease (CVD) according to comorbidities and suggested LDL-C treatment goals in Korean people with T2DM in nationwide cohort data.

METHODS

Using the Korean National Health Insurance Service database, 248,002 people aged 30 to 90 years with T2DM who underwent routine health check-ups during 2009 were included. Subjects with previous CVD were excluded from the study. The primary outcome was incident CVD, defined as a composite of myocardial infarction and ischemic stroke during the follow-up period from 2009 to 2018.

RESULTS

The mean age of the study participants was 59.6±10.9 years, and median follow-up period was 9.3 years. CVD incidence increased in the order of DM duration of 5 years or more (12.04/1,000 person-years), hypertension (HT) (12.27/1,000 personyears), three or more CV risk factors (14.10/1,000 person-years), and chronic kidney disease (18.28/1,000 person-years). The risk of incident CVD increased linearly from an LDL-C level of ≥70 mg/dL in most patients with T2DM. In T2DM patients without HT or with a DM duration of less than 5 years, the CVD incidence increased from LDL-C level of ≥100 mg/dL.

CONCLUSION

For primary prevention of CVD in Korean adults with T2DM, it can be helpful to lower LDL-C targets when there are chronic kidney disease, HT, a long duration of diabetes mellitus, or three or more CV risk factors.

Acute Pancreatitis and the Risk of Dementia in Diabetes: A Nationwide Cohort Study Using Korean Healthcare Claims Database

BACKGROUND

Diabetes is a major risk factor for the development of dementia, which has been proven to be associated with systemic inflammation. Acute pancreatitis, also a local and systemic inflammatory disease, is the most common gastrointestinal disease requiring acute hospitalization.

OBJECTIVE

The effect of acute pancreatitis on dementia was investigated in type 2 diabetic patients.

METHODS

Data was collected from the Korean National Health Insurance Service. The study sample included type 2 diabetes patients who received general health examination from 2009 to 2012. Cox proportional hazard regression analysis was used to evaluate the association between acute pancreatitis and dementia with adjustment of confounders. Stratified subgroup analysis by age, sex, smoking, alcohol consumption, hypertension, dyslipidemia, and body mass index was conducted.

RESULTS

Among the 2,328,671 participants in total, 4,463 patients had a history of acute pancreatitis before the health examination. During a median follow-up of 8.1 (IQR, 6.7-9.0) years, 194,023 participants (8.3%) developed all-cause dementia. Previous history of acute pancreatitis was a significant risk factor for dementia after adjustment of confounding variables (HR 1.39 [95% CI 1.26-1.53]). In the subgroup analysis, patient characteristics such as age under 65 years, male, current smoker, and alcohol consumption were significant risk factors for dementia in patients with a history of acute pancreatitis.

CONCLUSION

The history of acute pancreatitis was associated with the development of dementia in patients with diabetes. Because the risk of dementia increases with alcohol consumption and smoking in diabetic patients with history of acute pancreatitis, abstinence from alcohol and smoking should be recommended.

Clinical benefits of concomitant surgical ablation for atrial fibrillation in patients undergoing mitral valve surgery

BACKGROUND

The maze procedure is the dominant concomitant surgery performed with mitral valve (MV) surgery in patients with atrial fibrillation (AF). Most clinical recommendations regarding the maze procedure depend on the individual maze expert centers.

OBJECTIVE

The purpose of this study was to evaluate the clinical benefits of the maze procedure during MV surgery in a national cohort.

METHODS

Using the national health claims database established by the National Health Insurance Service of South Korea, data on subjects with AF who had undergone MV surgery from 2009 to 2017 were reviewed. The outcomes of interest were mortality; occurrence of ischemic or hemorrhagic stroke; hospitalization for bleeding events; and the composite of death, cerebrovascular accident, and major bleeding. Propensity score (PS) matching was performed for baseline adjustment.

RESULTS

Among 9501 subjects, the maze procedure was performed in 5508 (58.0%). In the PS-matched cohort (3376 pairs), the risk of the composite event was significantly lower in the maze group (hazard ratio [HR] 0.799; 95% confidence interval [CI] 0.731-0.873) than in the nonmaze group. The superiority of the maze procedure was similar for individual clinical events, including death (HR 0.795; 95% CI 0.711-0.889); ischemic stroke (HR 0.788; 95% CI 0.67-0.926); and major bleeding (HR 0.749; 95% CI 0.627-0.895), but not for hemorrhagic stroke (HR 0.984; 95% CI 0.768-1.262). In subgroup analyses of the composite events, these benefits were consistent among subjects aged ≥70 years or <70 years, surgery type (replacement vs repair), MV pathologies, and subjects with CHA₂DS₂-VASc score ≥4 or <4.

CONCLUSION

The addition of the maze procedure during MV surgery provided protective effects in the composite outcome of interest.

Association between Low-Density Lipoprotein Cholesterol Level and Cardiovascular Outcomes in Korean Adults: A Nationwide Cohort Study

BACKGROUND

To validate the treatment target of low-density lipoprotein cholesterol (LDL-C) level according to the cardiovascular disease (CVD) risk which was recommended by Korean dyslipidemia guideline.

METHODS

We used the Korean National Health Insurance Service database which included 3,958,048 people aged 20 to 89 years who underwent regular health screening. The primary outcome was incident CVD, defined as a composite of myocardial infarction and stroke during the follow-up period from 2009 to 2018.

RESULTS

The risk of CVD increased from LDL-C level of 70 mg/dL in very high-risk and high-risk groups and from 130 mg/dL in moderate-risk and low-risk groups. Adjusted hazard ratios (HRs) of LDL-C ranges 70-99, 100-129, 130-159, 160-189, and ≥190 mg/dL were 1.20 (95% confidence interval [CI], 1.08-1.33), 1.27 (1.15-1.42), 1.39 (1.23-1.56), 1.69 (1.45-1.96), and 1.84 (1.49- 2.27) in very high-risk group, and 1.07 (1.02-1.13), 1.16 (1.10-1.21), 1.29 (1.22-1.36), 1.45 (1.36-1.55), and 1.73 (1.58-1.90) in high-risk group. Adjusted HRs (95% CI) of LDL-C ranges 130-159, 160-189, and ≥190 mg/dL were 1.15 (1.11-1.20), 1.28 (1.22- 1.34), and 1.45 (1.36-1.54) in moderate-risk group and 1.07 (1.02-1.13), 1.20 (1.13-1.26), and 1.47 (1.37-1.57) in low-risk group.

CONCLUSION

We confirmed the incidence of CVD was increased in higher LDL-C range. The risk of CVD increased from ≥70 mg/dL of LDL-C in very high-risk and high-risk groups, and from ≥130 mg/dL of LDL-C in moderate-risk and low-risk groups in Korean adults.

Diabetes screening in South Korea: a new estimate of the number needed to screen to detect diabetes

BACKGROUND/AIMS

The Korean Diabetes Association (KDA) guidelines recommend adults aged ≥ 40 years and adults aged ≥ 30 years with diabetes risk factors for diabetes screening. This study aimed to determine the age threshold for diabetes screening in Korean adults.

METHODS

This study was based on the analyses of Korean adults aged ≥ 20 years using the Korea National Health and Nutrition Examination Survey (KNHANES) and the National Health Insurance Service-National Sample Cohort (NHIS-NSC). To evaluate screening effectiveness, we calculated the number needed to screen (NNS).

RESULTS

NNS to detect diabetes decreased from 63 to 34 in the KNHANES and from 71 to 42 in the NHIS-NSC between the ages of 30-34 and 35-39. When universal screening was applied to adults aged ≥ 35, the NNS was similar to that of adults aged ≥ 40. Compared to the KDA guidelines, the rate of missed screening positive in adults aged ≥ 20 decreased from 4.0% to 0.2% when the newly suggested screening criteria were applied.

CONCLUSION

Universal screening for adults aged ≥ 35 and selective screening for adults aged 20 to 34, considering diabetes risk factors, may be appropriate for detecting prediabetes and diabetes in South Korea.

Evaluation of the Paradoxical Association Between Lipid Levels and Incident Atrial Fibrillation According to Statin Usage: A Nationwide Cohort Study

Objective

Higher levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) are associated with a lower risk of atrial fibrillation (AF). Statin use might exert confounding effects on the paradoxical associations; however, the relationships that distinguish statin users from non-users have not been thoroughly evaluated.

Methods

From the Korean National Health Insurance Database, we included 9,778,014 adults who underwent a health examination in 2009. The levels of TC and LDL-C at the health examination were categorized into quartile values of the total study population. We grouped the study population into statin users and non-users and investigated the associations between TC, LDL-C, and the risk of incident AF.

Results

Of the total population, 867,336 (8.9%) were taking statins. During a mean follow-up of 8.2 years, inverse associations of TC - AF and LDL-C - AF were observed; higher levels of TC and LDL-C were associated with the lower risk of AF in the total population. Overall, statin users showed higher AF incidence rate than non-users, but the inverse associations of TC - AF and LDL-C - AF were consistently observed irrespective of statin usage; adjusted hazard ratio with 95% confidence interval was 0.81 (0.79-0.84) for statin users and 0.81 (0.80-0.83) for non-users in the highest TC quartile, and 0.84 (0.82-0.87) for statin users and 0.85 (0.84-0.86) for non-users in the highest LDL-C quartile (all p<0.001).

Conclusion

The paradoxical relationship between lipid levels (TC and LDL-C) and the risk of AF remains consistent in both statin users and non-users.

Renal outcomes of rivaroxaban compared with warfarin in Asian patients with nonvalvular atrial fibrillation: A nationwide population-based cohort study

Background

Further studies are needed to expand the evidence for the association of rivaroxaban with a lower risk of adverse renal outcomes in patients with atrial fibrillation (AF) as compared with warfarin, especially in Asians.

Objectives

To determine whether there are differences in adverse renal outcomes between rivaroxaban and warfarin-treated AF patients.

Methods

Using the Korean nationwide claims database partly linked to laboratory results, patients with AF who initiated warfarin or rivaroxaban from 1 January 2014 to 31 December 2017 were identified. Inverse probability of treatment weighting (IPTW) was used to balance the baseline characteristics of the two groups. The primary outcome (kidney failure) was defined as the need for maintenance dialysis or having kidney transplantation. For the exploratory analysis in a subset of patients with baseline and follow-up laboratory results, the composite of renal outcomes, including estimated glomerular filtration rate (eGFR) lower than 15 ml/min/1.73 m² at follow-up measurement, starting dialysis, or having kidney transplantation, ≥ 30% decline in eGFR, doubling of serum creatinine level, and acute kidney injury (AKI) were evaluated. The two groups were compared using Cox proportional hazards regression in the weighted population.

Results

We identified 30,933 warfarin users and 17,013 rivaroxaban users (51% of low dose rivaroxaban). After IPTW, the mean age was 70 years, and the mean CHA₂DS₂-VASc score was 3.9 in both groups. During a median follow-up of 0.93 (interquartile ranges 0.23-2.10) years, weighted incidence rates of kidney failure for warfarin and rivaroxaban were 0.83 and 0.32 per 100 person-years, respectively. Compared with the warfarin group, the rivaroxaban group was associated with a lower risk of kidney failure (hazard ratio [HR] 0.389, 95% confidence interval [CI] 0.300-0.499, p < 0.001). In patients with preexisting chronic kidney disease or eGFR ≤ 60 ml/min/1.73 m², rivaroxaban was more beneficial than warfarin in reducing the risk of kidney failure. For the composite of five renal outcomes in the exploratory analysis, the rivaroxaban group showed a lower risk than warfarin (HR 0.798, 95% CI 0.713-0.892, p < 0.001).

Conclusion

Rivaroxaban was associated with lower risks of renal adverse outcomes than warfarin in Korean patients with AF.

Weight change and risk of depression in patients with diabetic kidney disease: a nationwide population-based study

BACKGROUND

Several studies have reported that depression is prevalent in patients with diabetes or chronic kidney disease. However, the relationship between weight changes and the risk of depression has not been elucidated in patients with diabetic kidney disease (DKD).

METHODS

From the Korean National Health Insurance Service database, we selected 67,866 patients with DKD and body weight data from two consecutive health examinations with a 2-year interval between 2009 and 2012. Weight change over 2 years was categorized into five groups: ≥-10%, &lt;-10% to ≥-5%, &lt;-5% to &lt;5%, ≥5% to &lt;10%, and ≥10%. The occurrence of depression was monitored via the codes of International Statistical Classification of Diseases, 10th revision through the end of 2018.

RESULTS

During the 5.24-year follow-up, 17,023 patients with DKD developed depression. Weight change and the risk of depression had a U-shaped relationship: patients with ≥-10% weight change (hazard ratio [HR], 1.12) and those with ≥10% weight change (HR, 1.11) showed higher HRs for depression than those with &lt;-5% to &lt;5% weight change, even after adjusting for several confounding factors. In the subgroup analyses, the risk of depression tended to increase as weight gain or weight loss increased in all subgroups.

CONCLUSION

Both weight loss and weight gain increased the risk of depression in patients with DKD.

The association between changes in hepatic steatosis and hepatic fibrosis with cardiovascular outcomes and mortality in patients with New-Onset type 2 Diabetes: A nationwide cohort study

AIM

Non-alcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) have a synergistic effect on cardiovascular disease (CVD). We investigated the association of changes in hepatic steatosis and advanced hepatic fibrosis with risk of CVD and mortality in new-onset T2DM.

METHODS

Using the Korean National Health Insurance dataset, we included 120,256 patients with new-onset T2DM. Hepatic steatosis and advanced hepatic fibrosis were determined using the fatty liver index (FLI) and BARD score. According to the changes of the two scores over two years, patients were divided into four groups and analyzed for development of myocardial infarction (MI), stroke, heart failure (HF), and mortality.

RESULTS

Incident hepatic steatosis was associated with increased development of stroke, HF, and mortality compared with non-NAFLD (all p < 0.05). Regression and persistent hepatic steatosis were associated with increased risk of MI, stroke, HF, and mortality compared with non-NAFLD (all p < 0.05). Persistent advanced hepatic fibrosis was associated with increased risk of stroke, HF, and mortality (all p < 0.05).) Compared with persistent hepatic fibrosis, regression of hepatic fibrosis was associated with decreased risk of stroke, HF, and mortality (all p < 0.05).

CONCLUSIONS

Changes in FLI or BARD score were associated with CVD and mortality in new-onset T2DM.

Impact of mental disorders on the risk of atrial fibrillation in patients with diabetes mellitus: a nationwide population-based study

BACKGROUND

It is unclear whether mental disorders are an independent risk factor for atrial fibrillation (AF) in patients with diabetes. We aimed to investigate whether patients with diabetes who have mental disorders have an increased risk for AF.

METHODS

Using the Korea National Health Insurance Service database, we enrolled 2,512,690 patients diagnosed with diabetes without AF between 2009 and 2012. We assessed five mental disorders: depression, insomnia, anxiety, bipolar disorder, and schizophrenia. Newly diagnosed AF was identified during the follow-up period, and multivariate Cox regression analysis was performed.

RESULTS

Among the 2,512,690 patients (mean age 57.2 ± 12.3 years; 60.1% men), 828,929 (33.0%) had mental disorders. Among the five mental disorders, anxiety (68.1%) was the most common, followed by insomnia (40.0%). During a median follow-up duration of 7.1 years, new-onset AF was diagnosed in 79,525 patients (4.66 per 1,000 person-years). Patients with diabetes who had mental disorders showed a higher risk for AF (adjusted hazard ratio [HR] 1.19; 95% confidence interval [CI] 1.17-1.21; p-value < 0.001). Depression, insomnia, and anxiety were significantly associated with higher risk for AF (adjusted HR [95% CI]: 1.15 [1.12-1.17], 1.15 [1.13-1.18], and 1.19 [1.67-1.21], respectively; all p-values < 0.001), whereas bipolar disorder and schizophrenia were not.

CONCLUSIONS

Mental disorders, especially depression, insomnia, and anxiety, were associated with an increased risk for AF in patients with diabetes. Greater awareness with a prompt diagnosis of AF should be considered for patients with both DM and mental disorders.

The impact of socioeconomic deprivation on the risk of atrial fibrillation in patients with diabetes mellitus: A nationwide population-based study

Objective

To evaluate the relationship between socioeconomic status and the risk of atrial fibrillation (AF) in patients with diabetes mellitus (DM).

Research design and methods

From the National Health Insurance Service (NHIS) database, we identified 2,429,610 diabetic patients who underwent national health check-ups between 2009 and 2012. Tracing back the subjects for 5 years from the date of health check-up, we determined the subjects’ income and whether they received medical aid (MA) during the past 5 years. Subjects were divided into six groups according to the number of years of receiving (MA groups 0 through 5) and into four groups according to socioeconomic status change during the past 5 years. We estimated the risk of AF for each group using the Cox proportional-hazards model.

Results

During a median follow-up of 7.2 ± 1.7 years, 80,257 were newly identified as AF. The MA groups showed a higher risk of AF than the non-MA group with the hazard ratios (HRs) and 95% confidence interval (CI) 1.32 (1.2–1.44), 1.33 (1.22–1.45), 1.23 (1.13–1.34), 1.28 (1.16–1.4), and 1.50 (1.39–1.63) for MA groups 1 through 5, respectively. Dividing subjects according to socioeconomic condition change, those who experienced worsening socioeconomic status (non-MA to MA) showed higher risk compared to the persistent non-MA group (HR 1.54; 95% CI 1.38–1.73).

Conclusion

Low socioeconomic status was associated with the risk of AF in patients with diabetes. More attention should be directed at alleviating health inequalities, targeting individuals with socioeconomic deprivation to provide timely management for AF.

Risk of cardiovascular disease and mortality in patients with diabetes and acute pancreatitis history: a nationwide cohort study

Patients with acute pancreatitis (AP) may have an increased risk of cardiovascular disease (CVD). Few studies have dealt with the association between AP and the risk of CVD in diabetic patients. This study aimed to investigate the risk of CVD and mortality in patients with diabetes and AP history by analyzing a large-scale national claims database in Korea. Data from the Korean National Health Insurance Service database was analyzed. A total of 2,746,988 participants with type 2 diabetes mellitus that underwent a general health examination between 2009 and 2012 were enrolled. The participants were divided into two groups according to AP history (yes or no) prior to the examination date, and follow-up data until 2018 was analyzed. The primary endpoint was the occurrence of stroke, myocardial infarction (MI), or death. The Cox proportional hazards regression analysis was used to evaluate the association between AP history and the risk of stroke, MI, and mortality. After exclusion, the included number of participants with and without AP history were 3,810 and 2,258,910, respectively. The presence of AP history showed a significantly higher incidence of stroke, MI, and mortality. The adjusted hazard ratios (95% confidence interval) for the risk of stroke, MI, and mortality were 1.534 (1.342-1.753), 1.998 (1.733-2.303), and 2.353 (2.200-2.515), respectively. Age < 65, male sex, current smoking, and drinking significantly increased the risk of death in the subgroup analyses. The risk of stroke, MI, and mortality was significantly higher in diabetic participants with AP history than those without AP history at 9-year follow-up. This suggests that active management of cardiovascular risk factors is necessary in diabetic patients with AP history.

Association between early rhythm control and the risk of dementia in patients with atrial fibrillation and prior history of stroke: a nationwide population-based study

Background

Patients with atrial fibrillation (AF) who experienced stroke before are at high risk for dementia. Although early rhythm control in patients with AF reduces the risk of stroke, there is a lack of evidence on whether early rhythm control reduces the risk of developing dementia in patients with new-onset AF and a history of prior stroke.

Purpose

To compare the risk of dementia between early rhythm control therapy and usual care in patients with new-onset AF and a history of prior stroke

Methods

Using the Korean nationwide claims database, we identified patients who were newly diagnosed as AF and had a history of prior stroke. Patients with prevalent dementia were excluded. Patients who received rhythm control therapy, including antiarrhythmic drug, direct current cardioversion, or AF catheter ablation, within 1 year after incident AF were defined as the early rhythm control group, otherwise as the usual care group. The inverse probability of treatment weighting method was used to balance baseline characteristics between the two groups. The incidence of all dementia, Alzheimer dementia, and vascular dementia were evaluated during follow-up.

Results

A total of 41,370 patients were included (mean age, 70±11 years; mean CHA2DS2-VASc score 5.3±1.6; 43% female); 10,213 were in the early rhythm control group and 31,157 in the usual care group. All patients received oral anticoagulants. During a median 2.7 years of follow-up, 6414 patients developed incident dementia (incidence rate, 4.9 per 100 person-years). Compared to usual care, early rhythm control was associated with lower risks of all dementia, Alzheimer dementia, and vascular dementia (weighted hazard ratio [95% confidence interval], 0.825 [0.776–0.876], 0.831 [0.774–0.893], and 0.800 [0.702–0.913], respectively, all p&lt;0.001) (Figure 1). The beneficial effect of early rhythm control on the risk of dementia were consistent regardless of the characteristics of prior stroke, for example, recent stroke within 6-month from their enrollment, disabling stroke that required continuous rehabilitation therapy, and severe stroke causing intensive care unit admission.

Conclusion

Early rhythm control within 1 year after AF diagnosis might be beneficial to prevent dementia in patients with incident AF and a history of stroke. To prevent progression of further cognitive dysfunction, early rhythm control should be considered in these patients.

Funding Acknowledgement

Type of funding sources: None.

A synergistic impact of early rhythm control and lifestyle modification on the risk of stroke in patients with new-onset atrial fibrillation: a Korean nationwide population-based cohort study

Background

Early rhythm control therapy and lifestyle modification have both been associated with a lower risk of stroke in patients with atrial fibrillation (AF). Although guidelines have emphasized integrated care for patients with AF to improve clinical outcomes, the synergistic impact of early rhythm control therapy and lifestyle modification on the risk of stroke is unclear.

Purpose

To evaluate the impact of the combination of early rhythm control therapy and lifestyle modification on the risk of stroke

Methods

Based on data from the Korean National Health Insurance Service database, we included patients with new-onset AF between January 2009 and December 2016. Based on questionnaires from health checks, patients with ≥2 healthy lifestyle behaviors among quitting smoking, abstaining from alcohol, and performing regular exercise were defined as “healthy lifestyle” group. Patients who received rhythm control therapy within 2-year after new-onset AF were defined as the early rhythm control group. With a two-by-two factorial design, patients were categorized into 4 groups as follows: (i) those without early rhythm control and healthy lifestyle (group 1); (ii) those with a healthy lifestyle but without early rhythm control (group 2); (iii) those with early rhythm control but without healthy lifestyle (group 3); and (iv) those with both early rhythm control and healthy lifestyle (group 4). The primary outcome was stroke.

Results

Among a total of 208,662 patients, 46,972, 110,479, 15,133, and 36,078 patients were included in group 1, 2, 3, and 4, respectively. For the early rhythm control group, the mean duration from AF diagnosis to rhythm control therapy was 27±76 days. During a median follow-up of 4.2 years, 9905 patients had an incident stroke (incidence rate, 10.6 per 100 person-years). After multivariable adjustment, compared to group 1, group 2 (healthy lifestyle only) and group 3 (early rhythm control only) were associated with a lower risk of stroke (HR and 95% CI: 0.769, 0.728–0.881, and 0.774, 0.703–0.852, respectively) (Figure 1). Group 4 with early rhythm control and a healthy lifestyle had the lowest risk of stroke among all groups (HR 0.575, 95% CI 0.536–0.617 compared to group 1) (Figure 1). After propensity score (PS) weighting for group 2 and 4, additional early rhythm control based on healthy lifestyle was associated with a lowered risk of stroke by 22% (Figure 2). After PS weighting between groups 3 and 4, additional lifestyle modification based on early rhythm control was associated with a lowered risk of stroke by 27% (Figure 2).

Conclusion

In this large-scale observational cohort study, early rhythm control therapy and healthy lifestyle behavior might reduce the risk of stroke in patients with new-onset AF, consistent with the results from recent randomized clinical trials. Furthermore, implementing both early rhythm control therapy and a healthy lifestyle could synergize stroke prevention in these populations.

Funding Acknowledgement

Type of funding sources: None.

Increased risk of atrial fibrillation in patients with uterine fibroids: a nationwide population-based study

Background

Uterine fibroid, the most common benign neoplasm of the uterus, is associated with an elevated risk of cardiovascular disease. The link between incident atrial fibrillation (AF) and the uterine fibroid is unclear because earlier studies focused primarily on the development of atherosclerosis and hypertension. We aimed to investigate the risk of AF in patients with uterine fibroid.

Methods

This is a retrospective cohort study using the Korean National Health Insurance Service database (NHIS). From 2009 to 2012, a total of 2,574,349 women (20 to 40 years old) who underwent general health examinations were included. Diagnosis of uterine fibroids and surgical treatment status was defined by the international classification of diseases, 10th revision codes, and procedural codes from the Korean NHIS. The primary outcome was newly diagnosed AF. The risk of AF according to the uterine fibroids and their surgical treatment status was evaluated using Cox proportional-hazard models.

Results

Of the total population, the mean age was 29.76±4.27 years, and 20,682 (0.8%) were identified to have uterine fibroid. Incident AF was identified in 3,868 patients (61 in the fibroid group, 3,807 in the control group) during a mean follow-up of 7.3±1.1 years. Patients of the uterine fibroid group showed a higher incidence of AF compared to the control group (0.41 and 0.20 per 1000 person-years, respectively, Figure 1). Multivariate Cox-regression analysis presented that uterine fibroid was an independent risk factor of AF: hazard ratio (HR) 1.50, 95% confidence interval (CI) 1.16–1.93, p=0.002. Compared to the control group, uterine fibroid patients who underwent surgical treatment tend to show a lower risk for AF (HR 1.22, 95% CI 0.79–1.90) than patients without surgical treatment (HR 1.69, 95% CI 1.24–2.30), though statistical significance was indeterminate (Figure 2). After propensity score matching, patients of the uterine fibroid group showed higher risk of AF when compared to the control group (HR 1.77, 95% CI 1.32–2.63, p&lt;0.001), which was in line with our main results. The presence of uterine fibroid was consistently associated with higher risk of AF among all subgroups except for the stroke subgroup.

Conclusion

Patients with uterine fibroids are predisposed to an increased risk of AF compared to the control group. Careful monitoring of arrhythmia development would be warranted in patients of uterine fibroid and surgical treatment as it is associated with a modest risk decrement of incident AF.

Funding Acknowledgement

Type of funding sources: None.

Paradoxical association between lipid levels and incident atrial fibrillation according to statin usage

Background

In epidemiology studies, a higher level of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) is associated with a lower risk of atrial fibrillation (AF). Statin use might exert possible confounding effects in the paradoxical relationship; however, the inverse link between AF and cholesterol level that distinguishes statin users from non-users has not been evaluated.

Objective

We investigated the epidemiological relationships of TC–AF and LDL-C–AF in statin users and non-users, respectively.

Methods

From the Korean National Health Insurance Service database, we included 9,778,014 adults who underwent a health examination in 2009 and had no prior AF history. The levels of TC and LCL-C at the health exam were categorized in quartile (Q) and decile (D) values of the total study population. The study population was grouped into statin users and non-users, and TC–AF and LDL-C–AF relationships were evaluated.

Results

867,336 (8.9%) were on statin use among the total population. Statin users showed higher TC level (208.4±55.6 vs. 194.1±39.5 mg/dL, p&lt;0.001) and LDL-C level (123.0±102.2 vs. 121.3±226.3, p&lt;0.001) compared to non-users. Inverse associations of TC–AF and LCL-C–AF were observed; higher levels of TC and LDL-C were associated with a lower risk of AF. The hazard ratios (HR) and 95% confidence intervals (CI) were 0.797 (0.786–0.809) for the highest quartile of TC (Q4, TC ≥218) and 0.832 (0.82–0.843) for the highest quartile of LDL-C (Q4, LDL-C ≥135) when adjusted by age, sex, lifestyle behaviors, comorbidities, and low-income status. Statin users exhibited higher AF incidence rate than non-statin users, but the association in statin users generally tracked that seen among non-statin users demonstrating similar HR in Q4 of TC [0.812 (0.790–0.835) for statin users and 0.812 (0.798–0.826) for non-statin users] and LDL-C [0.842 (0.819–0.865) for statin users and 0.849 (0.835–0.863) for non-statin users].

Conclusion

The paradoxical relationship between lipid levels (TC and LDL-C) and incident AF remained consistent both in statin users and non-users. Further research is required to investigate an underlying mechanism for the cholesterol paradox of AF which still seems evident despite the pleiotropic effects of statin.

Funding Acknowledgement

Type of funding sources: None.

Augmented risk of ischemic stroke in hypertrophic cardiomyopathy patients without documented atrial fibrillation

Background

Ischemic stroke is a common complication in patients with hypertrophic cardiomyopathy (HCM) (1). Although atrial fibrillation (AF) is a well-established risk factor for ischemic stroke in HCM, the risk of ischemic stroke in patients with HCM without documented AF is less recognized (1, 2). This study aimed to determine the risk of ischemic stroke and identify its risk factors in patients with HCM without documented AF.

Methods

This nationwide population-based cohort study used the Korean National Health Insurance database. After excluding patients with a prior history of AF, thromboembolic events, cancer, or the use of anticoagulants, we identified 8,328 HCM patients without documented AF and 1:2 propensity score-matched 16,656 non-HCM controls. The clinical outcome was an incident ischemic stroke.

Results

During a mean follow-up of approximately 6 years, ischemic stroke occurred in 328/8,328 (3.9%) patients with HCM and 443/16,656 (2.7%) controls. Among individuals who developed ischemic stroke, the proportion of AF concomitantly detected accounted for 26.5% (87/328) and 5.8% (26/443) in the HCM and control groups, respectively. The overall incidence of ischemic stroke was 0.716/100 person-years in the HCM group, which was significantly higher than that in the control group (0.44/100 person-years) (HR 1.643; 95% CI, 1.424–1.895; P&lt;0.001, Figure 1). The subgroup analysis according to age, sex, and comorbidities (chronic heart failure, hypertension, dyslipidemia, and vascular disease) consistently demonstrated a higher risk of ischemic stroke in the HCM group (P for interaction &gt;0.05). In the HCM group, age ≥65 years (adjusted hazard ratio [HR] 2.741; 95% confidence interval [CI], 2.156–3.486; P&lt;0.001) and chronic heart failure (adjusted HR 1.748; 95% CI, 1.101–2.745; P=0.018) were independent risk factors for ischemic stroke. Overall incidence was 1.360/100 in patients with HCM aged ≥65 and 2.315/100 person-years years in those with chronic heart failure, respectively. Also, compared to controls aged &lt;65 years and without CHF, adjusted HR for ischemic stroke was 4.756 (95% CI 3.807–5.867) in patients with HCM aged ≥65 years and 2.539 (95% CI 1.638–3.936) in those with CHF, respectively (Figure 2).

Conclusions

Patients with HCM without documented AF are at a higher risk of ischemic stroke than the propensity score-matched general population. Age ≥65 years and chronic heart failure are two strong independent risk factors for ischemic stroke in this population.

Funding Acknowledgement

Type of funding sources: None.

Impact of metabolic syndrome on the risk of ischemic stroke in non-anticoagulated atrial fibrillation patients having low CHA2DS2-VASc scores

Background

Metabolic syndrome (MetS) predisposes to a thromboembolic state. However, conflicting results have been reported on whether MetS confers an increased risk of ischemic stroke in atrial fibrillation (AF), especially in patients with low CHA2DS2-VASc score who are not indicated for oral anticoagulant therapy.

Purpose

We investigated the risk of ischemic stroke according to the presence of MetS, the number of MetS components (metabolic burden), and the individual metabolic components in non-anticoagulated AF patients with low CHA2DS2-VASc score.

Methods

A total of 76,015 oral anticoagulant-naïve AF patients with low CHA2DS2-VASc score (0,1 in male and 1 in female) were included from the Korean National Health Insurance Service database. The status of MetS and individual metabolic components were evaluated based on health examination data within two years of AF diagnosis. We estimated the risk of ischemic stroke according to MetS, metabolic burden, and an individual component of MetS using Cox proportional-hazards models.

Results

The mean age was 49.8±11.1 years and 52,388 (68.9%) were male. The average CHA2DS2-VASc score was 0.7±0.5 and MetS was prevalent among 21,570 (28.4%) of the study population. During a mean follow-up of 5.1 years, ischemic stroke was developed in 1,395 (1.84%) patients. MetS was associated with a higher risk of ischemic stroke after adjustment for age, sex, lifestyle behaviors, low income, and cardiovascular comorbidities: adjusted hazard ratio (aHR) 1.19, 95% confidence interval (CI) 1.06–1.33, p=0.002. A positive linear correlation was observed between metabolic burden and ischemic stroke risk. Patients with five MetS components showed the highest aHR of 1.55 (95% CI 1.14–2.11, Figure 1 and Figure 2), whereas those with a single MetS component had a marginal risk of ischemic stroke (aHR 1.18, 95% CI 0.99–1.41). Among individual metabolic components, elevated blood pressure and increased waist circumference was significantly associated with an increased risk of ischemic stroke: aHR (95% CI), 1.45 (1.30–1.62), p&lt;0.001, and 1.15 (1.03–1.30), p=0.016, respectively.

Conclusions

Among AF patients initially with CHA2DS2-VASc score 0 and 1 with no anticoagulation, the presence of MetS is associated with an increased risk of ischemic stroke. Given the linear incremental correlation between metabolic burden and ischemic stroke, special attention to the care of metabolic derangements is required in AF patients who are not indicated for anticoagulation.

Funding Acknowledgement

Type of funding sources: None.

Association among Current Smoking, Alcohol Consumption, Regular Exercise, and Lower Extremity Amputation in Patients with Diabetic Foot: Nationwide Population-Based Study

BACKGRUOUND

The present study investigates whether modifiable behavioral factors of current cigarette smoking, heavy alcohol consumption, and regular exercise are associated with risk of lower extremity amputation (LEA) in diabetic patients.

METHODS

A total of 2,644,440 diabetic patients (aged ≥20 years) was analyzed using the database of the Korean National Health Insurance Service. Cox proportional hazard regression was used to assess adjusted hazard ratios (HRs) for the behavioral factors with risk of LEA under adjustment for potential confounders.

RESULTS

The risk of LEA was significantly increased by current cigarette smoking and heavy alcohol consumption (HR, 1.436; 95% confidence interval [CI], 1.367 to 1.508 and HR, 1.082; 95% CI, 1.011 to 1.158) but significantly decreased with regular exercise (HR, 0.745; 95% CI, 0.706 to 0.786) after adjusting for age, sex, smoking, alcohol consumption, exercise, low income, hypertension, dyslipidemia, body mass index, using insulin or oral antidiabetic drugs, and diabetic duration. A synergistically increased risk of LEA was observed with larger number of risky behaviors.

CONCLUSION

Modification of behaviors of current smoking, heavy alcohol intake, and exercise prevents LEA and can improve physical, emotional, and social quality of life in diabetic patients.

Underweight Is Associated with a Higher Risk of Acute Pancreatitis in Type 2 Diabetes: A Nationwide Cohort Study

Type 2 diabetes is known as a risk factor for acute pancreatitis, but the risk of acute pancreatitis according to glycemic status and body mass index (BMI) has remained unknown. Therefore, we aim to investigate the risk of acute pancreatitis according to BMI and glycemic status. We included 3,912,496 subjects from the Korean National Health Insurance System cohort who underwent the National Health Screening program in 2009. Each subject’s clinical course was examined through follow-ups until December 2018. BMI and glycemic status were each categorized into five groups. Hazard ratios (HRs) of acute pancreatitis according to BMI and glycemic status were calculated. The adjusted HRs of acute pancreatitis were the highest in the underweight group (BMI < 18.5) in all five glycemic status categories. The HR of acute pancreatitis in the underweight group increased as the glycemic status worsened, excluding the category of diabetes for more than five years (HR 1.381 for normal fasting glucose; 1.805 for impaired fasting glucose; 2.332 for new-onset diabetes; 4.51 for diabetes duration <5 years; 4.135 for diabetes duration ≥5 years). We found that the risk of acute pancreatitis was further increased in the underweight group, depending on the status and duration of type 2 diabetes.

Relationship between Chronic Rhinosinusitis and the Incidence of Head and Neck Cancer: A National Population-Based Study

We analyzed the relationship between chronic rhinosinusitis (CRS) and the incidence of head and neck cancers (HNCs) in a Korean adult population. This retrospective cohort study included data from the Korean National Health Insurance Service database. Adjustments were made to minimize risk variables for sex, age, diabetes, hypertension, dyslipidemia, and rhinitis between the two groups. The primary endpoint was newly diagnosed HNC between January 2009 and December 2018. Among 1,337,120 subjects in the Korean National Health Insurance Service database, data from 324,774 diagnosed with CRS (CRS group) and 649,548 control subjects (control group) were selected. Patients with CRS exhibited a statistically significant greater risk for nasal cavity/paranasal sinus cancer, hypopharynx/larynx cancer, and thyroid cancer compared with the control group. In the CRS group, the adjusted hazard ratios for nasal cavity/paranasal sinus cancer were 1.809 (95% confidence interval (CI) 1.085–3.016), 1.343 (95% CI 1.031–1.748) for hypopharynx and larynx cancer, and 1.116 (95% CI 1.063–1.173) for thyroid cancer. CRS was associated with a higher incidence of HNCs. Therefore, physicians should carefully consider the possibility of HNC progression and implement therapeutic strategies to minimize the impact of these diseases.

Habitual Alcohol Intake and Risk of Atrial Fibrillation in Young Adults in Korea

IMPORTANCE

Guidelines recommend that all risk factors for early-onset atrial fibrillation, including lifestyle factors, be proactively managed, considering the poor prognosis of the disease. Not much is known about the association of cumulative alcohol intake with the risk of atrial fibrillation in young adults aged 20 to 39 years, especially among heavy drinkers.

OBJECTIVE

To explore the association of alcohol consumption with the risk of incident atrial fibrillation in young adults.

DESIGN, SETTING, AND PARTICIPANTS

Using the National Health Insurance Service database, a nationwide population-based cohort study of adults aged 20 to 39 years without prior atrial fibrillation who underwent 4 serial annual health examinations between 2009 and 2012 was conducted. The cumulative alcohol consumption burden over 4 years was calculated by assigning 1 point to more than moderate drinking (≥105 g of alcohol per week) each year. Additionally, a semiquantitative cumulative burden was calculated by assigning 0, 1, 2, and 3 points to non, mild (<105 g per week), moderate (105-210 g per week), and heavy (≥210 g per week) drinking, respectively. Data were analyzed from May to June 2021.

EXPOSURE

Amount of alcohol intake in 4 years.

MAIN OUTCOMES AND MEASURES

The primary outcome was incident atrial fibrillation during the follow-up period.

RESULTS

A total of 1 537 836 participants (mean [SD] age 29.5 [4.1] years, 1 100 099 [71.5%] male) were included in the final analysis. According to the 4-year cumulative burden of alcohol consumption stratified by moderate to heavy drinking, 889 382 participants (57.8%) were in the burden 0 group, 203 374 participants (13.2%) in the burden 1 group, 148 087 participants (9.6%) in the burden 2 group, 144 023 participants (9.4%) in the burden 3 group, and 152 970 participants (9.9%) in the burden 4 group. During a median (IQR) follow-up of 6.13 (4.59-6.48) years, atrial fibrillation was newly diagnosed in 3066 participants (0.36 per 1000 person-years). Participants with a cumulative burden of 4 points who continued more than moderate drinking for 4 years showed a 25% higher risk of atrial fibrillation compared with 0-point participants who kept non-to-mild drinking over 4 years (adjusted HR, 1.25; 95% CI, 1.12-1.40). In a semiquantitative analysis, participants who sustained heavy drinking for 4 consecutive years were associated with a 47% higher atrial fibrillation risk than those who remained nondrinkers over 4 years (aHR, 1.47, CI 1.18-1.83).

CONCLUSIONS AND RELEVANCE

Persistent moderate to heavy drinking and higher cumulative alcohol consumption burden might increase the risk of atrial fibrillation even in young adults aged 20 to 39 years.

Net clinical benefit of antithrombotic therapy for atrial fibrillation patients with stable coronary artery disease

Objectives

To compare the net clinical benefit of oral anticoagulant (OAC) monotherapy to OAC plus single antiplatelet therapy (SAPT) in patients with atrial fibrillation (AF) and stable coronary artery disease (CAD) at 1- and 3-year after percutaneous coronary intervention (PCI).

Background

It has not been studied whether the net clinical benefit of the antithrombotic treatment options differs depending on the elapsed time from the index PCI.

Methods

Using the Korean nationwide claims database, we included AF patients who underwent PCI from 2009 to 2019 and constructed two cohorts: 1- and 3-year after PCI. In each cohort, the baseline characteristics of two groups were balanced using propensity score weighting. Ischemic stroke, myocardial infarction, major bleeding, and composite clinical outcomes were analyzed.

Results

Among patients with 1-year after PCI, OAC monotherapy (n = 678), and OAC plus SAPT (n = 3,159) showed comparable results for all clinical outcomes. In patients with 3-year after PCI, OAC monotherapy (n = 1,038) and OAC plus SAPT (n = 2,128) showed comparable results for ischemic stroke and myocardial infarction, but OAC monotherapy was associated with a lower risk of composite clinical outcomes (HR 0.762, 95% CI 0.607–0.950), mainly driven by the reduction of major bleeding risk (HR 0.498, 95% CI 0.345–0.701).

Conclusion

Oral anticoagulant monotherapy may be a comparable choice for patients with AF and stable CAD compared to OAC plus SAPT. In patients with stable CAD more than 3-year after index PCI, OAC monotherapy would be a better choice, being associated with less major bleeding and a positive net clinical benefit.

Association of Meibomian Gland Dysfunction with Oral Statin Use

This retrospective cross-sectional study aimed to determine the association of oral statin use, dry eye disease (DED), and meibomian gland dysfunction (MGD). A total of 93 subjects were included and divided into two groups: statin users (n = 45) and nonstatin users (n = 47). Significant differences were observed in the total cholesterol (p = 0.013), low-density lipoprotein (LDL) (p = 0.005), and meiboscore (p = 0.000) levels between the two groups. For stratified analysis, the statin group was divided into subgroups according to the type or dose of statin and total duration of statin use. However, there were no differences in clinical features between the subgroups. In multiple regression analysis, meiboscore was significantly associated with age (slope = 0.05, p = 0.00) and statin use (slope = −1.19, p = 0.00), with an R² of 0.44. Thus, older adults and participants who do not use statin appeared to have higher scores. In conclusion, although the mechanism is unclear, statins may exert a protective effect on the meibomian gland. Further lipidomic studies are required to determine the pharmacological effects of statins on the meibomian gland and other meibum components.

Associations between obesity parameters and the risk of incident atrial fibrillation and ischaemic stroke in the different age groups

Objective

Obesity and aging are important predisposing factors to atrial fibrillation (AF) and ischaemic stroke (IS). However, limited data comprehensively evaluated the relationships between obesity measurements and AF and IS in different ages.

Methods

A total of 9,432,332 adults from the Korean National Health Insurance Service Database were included. The study population was categorized into the six age subgroups by an increase every decade from the twenties. We evaluated AF and IS risk according to body mass index (BMI) and waist circumference (WC) in the different age groups.

Results

During a mean follow-up of 8.2 ± 1.0 years, BMI-AF presented a J-shaped association across ages. The highest hazard ratio (HR) of the BMI ≥ 30 kg/m² group was observed in subjects aged 30–39 years [HR 1.80, 95% CI 1.63–1.98, p < 0.001]. Underweight adults over 60 years also presented an increased AF risk. Incident IS risk increased in those with BMI over the normal range in early and midlife, but the association became obscured in adults aged > 60 years. Among the BMI ≥ 30 kg/m² groups, subjects aged 20–29 years presented the highest risk of IS [HR 3.00, 95% CI (2.34–3.84), p < 0.001]. Overall, WC-AF and WC-IS showed positive linear correlations, but the WC-IS association was weak in subjects aged ≥ 40 years.

Conclusion

The higher risks of AF and IS according to an increment of BMI and WC were most apparent among the young ages. The association between obesity measurements and IS was not significantly above the midlife. Weight management in the young and integrated risk factor management in the elderly are warranted.

Effects of Blood Pressure According to Age on End-Stage Renal Disease Development in Patients With Diabetes: A Nationwide Population-Based Cohort Study

Background:

Recent hypertension guidelines have recommended lower blood pressure (BP) targets in high-risk patients. However, there are no specific guidelines based on age or systolic and diastolic blood pressure (SBP and DBP, respectively). We aimed to assess the effects of age-related BP on development of end-stage renal disease (ESRD) in patients with diabetes.

Methods:

A total of 2 563 870 patients with diabetes aged >20 years were selected from the Korean National Health Screening Program from 2009 to 2012 and followed up until the end of 2019. Participants were categorized into age and BP groups, and the hazard ratios for ESRD were calculated.

Results:

During a median follow-up of 7.15 years, the incidence rates of ESRD increased with increasing SBP and DBP. The hazard ratio for ESRD was the highest in patients younger than 40 years of age with DBP≥100 mm Hg. The effect of SBP and DBP on ESRD development was attenuated with age (interaction P was <0.0001 for age and SBP, and 0.0022 for age and DBP). The subgroup analysis for sex, antihypertension medication, and history of chronic kidney disease showed higher hazard ratios for ESRD among males, younger than 40 years, not taking antihypertension medications and chronic kidney disease compared to those among females, older than 40 years, antihypertension medication, and nonchronic kidney disease groups.

Conclusions:

Higher SBP and DBP increase the risk of developing ESRD in patients with diabetes, and in particular, younger individuals face greater risk. Therefore, intensive BP management is warranted in younger patients to prevent ESRD.

Weight change and fracture risk in patients with diabetic kidney disease: A nationwide population-based study

Background

The increased risk of fracture has been associated with weight loss in patients with diabetes or chronic kidney disease. However, the relationship between weight changes over time and fracture risk in patients with diabetic kidney disease is still unknown.

Methods

A total number of 78,922 patients with diabetic kidney disease, aged ≥ 40 years, were selected using the Korean National Health Insurance Service database, between 2009 and 2012. They were followed up until the end of 2018. Weight change was defined as the difference in body weight from the index year to 2 years later. Weight changes were then divided into five categories, ranging from weight loss of ≥10% to weight gain of ≥10%.

Results

Fractures were identified in 9,847 patients with diabetic kidney disease, over a median follow-up of 5.2 years. The risk of composite fracture of the vertebral, hip, or other sites increased as the weight change increased. Specifically, patients with ≥10% weight loss (hazard ratio [HR], 1.286; 95% confidence interval [CI], 1.184–1.398) and ≥10% weight gain (HR, 1.198; 95% CI, 1.080–1.330) showed a higher HR compared to those with ≤ 5% weight change after adjusting for several confounding factors. Higher HR of vertebral and hip fractures was also seen with increased weight loss or gain. In particular, patients with ≥10% weight loss showed the highest HR for hip fractures (HR, 1.738; 95% CI, 1.489–2.028).

Conclusions

Both weight loss and weight gain increase the risk of fracture in patients with diabetic kidney disease. Therefore, patients with diabetic kidney disease who experience weight changes should be made aware of the risk of fracture.

Clustering of Unhealthy Lifestyle and the Risk of Adverse Events in Patients With Atrial Fibrillation

Background

Little is known regarding the risk of clinical outcomes depending on the clustering of lifestyle behaviors after atrial fibrillation (AF) diagnosis. This study evaluated the association between a cluster of healthy lifestyle behaviors and the risk of adverse outcomes in patients with AF.

Methods

Using the Korean National Insurance Service database, patients who were newly diagnosed with AF between 2009 and 2016 were included. A healthy lifestyle behavior score (HLS) was calculated by assigning 1 point each for non-current smoking, for non-drinking, and for performing regular exercise from the self-reported questionnaire in health examinations. The primary outcome was defined as major adverse cardiovascular event (MACE), including ischemic stroke, myocardial infarction, and hospitalization for heart failure.

Results

A total of 208,662 patients were included; 7.1% in HLS 0, 22.7% in HLS 1, 58.6% in HLS 2, and 11.6% in HLS 3 groups. Patients with HLS 1, 2, and 3 were associated with a lower risk of MACE than those with HLS 0 (adjusted hazard ratio [95% confidence interval (CI)]: 0.788 [0.762–0.855], 0.654 [0.604–0.708], and 0.579 [0.527–0.636], respectively). After propensity score weighting, consistent results were observed. The risk reduction of healthy lifestyle combinations was consistently observed in various subgroups, regardless of the CHA₂DS₂-VASc score and oral anticoagulant use.

Conclusion

Increased number of healthy lifestyle behaviors was significantly associated with lower MACE risk in patients with new-onset AF. These findings support the promotion of a healthy lifestyle to reduce the risk of adverse events in patients with AF.

Metabolic Syndrome as a Risk Factor of Endometrial Cancer: A Nationwide Population-Based Cohort Study of 2.8 Million Women in South Korea

Background

A positive relationship was reported between metabolic syndrome and the risk of endometrial cancer. Studies on the relationship between metabolic syndrome and endometrial cancer have been mainly conducted in post-menopausal women. We aimed to investigate the risk of endometrial cancer according to metabolic syndrome and menopausal status using the Korean nationwide population-based cohort.

Methods

We enrolled 2,824,107 adults (endometrial cancer group; N = 5,604 and control group; N= 2,818,503) from the Korean National Health Insurance Service checkup database from January 1 to December 31, 2009. The median follow-up duration was 8.37 years. Metabolic syndrome was diagnosed as having at least three of the following five components: abdominal obesity, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol, raised blood pressure, and hyperglycemia. Multivariate Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) to estimate endometrial cancer risk.

Results

The endometrial cancer risk was higher in the metabolic syndrome group than that in the non-metabolic syndrome group (HR, 1.362; 95% CI, 1.281–1.449). The association between metabolic syndrome and endometrial cancer risk was significant in the premenopausal subgroup (HR, 1.543; 95% CI, 1.39–1.713) and postmenopausal subgroup (HR, 1.306; 95% CI, 1.213–1.407). The incidence of endometrial cancer was more closely related to metabolic syndrome components in the pre-menopausal subgroup than those in the post-menopausal subgroup (for waist circumference, blood pressure, triglycerides and high-density lipoprotein cholesterol, all p for interaction <0.0001 respectively, and for fasting blood glucose, p for interaction 0.0188). The incidence of endometrial cancer positively correlated with the number of metabolic syndrome components (log-rank p <0.0001).

Conclusion

Our large population-based cohort study in Korean women suggests that metabolic syndrome and its accumulated components may be risk factors for endometrial cancer, particularly in the pre-menopausal women.

Risk of Dementia After Smoking Cessation in Patients With Newly Diagnosed Atrial Fibrillation

IMPORTANCE

Incident atrial fibrillation (AF) is associated with an increased risk of dementia. However, data on the association between smoking cessation after AF diagnosis and dementia risk are limited.

OBJECTIVE

To evaluate the association between changes in smoking status after AF diagnosis and dementia risk.

DESIGN, SETTING, AND PARTICIPANTS

This nationwide cohort study with 126 252 patients used data from the Korean National Health Insurance Service database, including patients who had a national health checkup examination within 2 years before and after AF diagnosis between January 1, 2010, and December 31, 2016. Based on their smoking status, participants were classified as never smokers, ex-smokers, quit smokers, and current smokers. Ex-smokers were defined as those who had quit smoking before the first examination and remained quit until the second examination. Patients who were current smokers at the first health examination but had quit smoking before the second examination were classed as quit smokers. The index date was the second health examination. Patients were followed up until dementia, death, or the study period ended (December 31, 2017), whichever occurred first. Data were analyzed from January 13, 2020, to March 29, 2022.

EXPOSURES

Smoking cessation after newly diagnosed AF.

MAIN OUTCOMES AND MEASURES

Dementia, including Alzheimer disease and vascular dementia, was the primary outcome. Cox proportional hazards regression model was used to estimate hazard ratios.

RESULTS

A total of 126 252 patients (mean [SD] age, 62.6 [12.0] years; 61.9% men) were included in the analysis. The mean (SD) CHA2DS2-VASc score, which measures the risk of ischemic stroke, was 2.7 (1.7). Smoking status of the total study population was as follows: 65 579 never smokers (51.9%), 34 670 ex-smokers (27.5%), 8919 quit smokers (7.1%), and 17 084 current smokers (13.5%). During a median of 3 years of follow-up, dementia occurred in 5925 patients (1.11 per 1000 person-years). After multivariable adjustment, the risk of quit smokers was significantly lower than that of current smokers (hazard ratio, 0.83 [95% CI, 0.72-0.95]).

CONCLUSIONS AND RELEVANCE

The findings of this cohort study suggest that all types of smoking were associated with a significantly higher risk of dementia in patients with new-onset AF. Smoking cessation after AF diagnosis was associated with a lower risk of dementia than among current smokers. These findings may support promoting smoking cessation to reduce dementia risk in patients with new-onset AF.

Type and Severity of Migraine Determines Risk of Atrial Fibrillation in Women

Objective

To evaluate sex differences in the risk of atrial fibrillation (AF) according to the type and severity of migraine.

Methods

We analyzed the nationwide health screening recipients in 2009 without previous AF diagnosis from the Korean National Health Insurance Service data. The diagnosis, type, and severity of migraine were determined using claims data. Newly developed AF was identified during a 10-year follow-up. Sex-difference in the effect of migraine on AF was evaluated.

Results

A total of 4,020,488 subjects were enrolled from January 1, to December 31, 2009 and followed-up through December 31, 2018; 4,986 subjects had migraine with aura (age 50.6 ± 14.0 years, men 29.3%); and 105,029 had migraine without aura (age 51.6 ± 14.3 years, men 30.9%). Risk of AF in a mild degree of migraine was similar to that in the control group, regardless of sex or the presence of aura. Severe migraine without aura modestly but significantly increased the risk of AF in both men and women compared to controls, with increase in AF risk being most prominent in women who had severe migraine with aura [incidence rate (IR) = 3.39, hazard ratio (HR)_adjust = 1.48, 95% confidence intervals (CI) = 1.18–1.85]. No significant association according to aura was observed in men with severe migraines (p for interaction 0.011).

Conclusion

Severe migraine with aura significantly increased the risk of incident AF in women, but not in men. Surveillance for incident AF and prompt lifestyle modification may be beneficial, particularly for young women suffering from severe migraine with aura.

Sex Differences in the Prevalence of Head and Neck Cancers: A 10-Year Follow-Up Study of 10 Million Healthy People

Background: Descriptive epidemiologists have repeatedly reported that males are more susceptible to head and neck cancers. However, most published data are those of cross-sectional studies, and no population-based cohort study has yet been published. The aim of this study was to compare the prevalence of head and neck cancers in healthy males with females. Methods: A retrospective cohort study using the Korean National Health Insurance Service database on 9,598,085 individuals who underwent regular health checkups from 1 January to 31 December 2009. We sought head and neck cancers developed during the 10-year follow-up. Results: A total of 10,732 (incidence rate (IR) per 1000 person-years 0.25) individuals were newly diagnosed with head and neck cancer among the 9,598,085 individuals during the 10-year follow-up. The IR was 0.19 in males (8500 affected) and 0.06 in females (2232 affected). Notably, the male−female ratio increased with age below 70 years but decreased thereafter. The male−female difference was most apparent for laryngeal cancer; the male IR was 11-fold higher in the 40 s and 20-fold higher in the 60 s, followed by hypopharyngeal cancer (6.8- and 24.2-fold). Males smoked more and drank more alcohol than females (p < 0.0001 *, p < 0.0001 *). When never-smokers/-drinkers (only) were compared, males remained at a 2.9-fold higher risk of head and neck cancer than females. The hazard ratios for head and neck cancers in males tended to increase in the lower part of the upper aerodigestive tract: larynx (13.9) > hypopharynx (10.9) > oropharynx (4.4) > nasopharynx (2.9) > sinonasal region (1.8) > oral (1.6). Only the salivary gland cancer incidence did not differ between the sexes; the gland is not in the upper aerodigestive tract. Conclusion: Males are much more susceptible to head and neck cancers than females regardless of whether they drink alcohol or smoke tobacco. Sex differences in the incidence of head and neck cancer are most evident in the 60 s in the lower part of the upper aerodigestive tract, such as the larynx and hypopharynx.

Age-dependent associations of body mass index with myocardial infarction, heart failure, and mortality in over 9 million Koreans

BACKGROUND

While obesity is a well-known cardiovascular risk factor, little is known whether age has a modifying effect.

AIM

To determine the age-dependent associations of BMI with cardiovascular outcomes.

METHODS

A population-based cohort of 9,278,433 Koreans without prior cardiovascular disease were followed up for the incidence of myocardial infarction (MI), heart failure (HF), and all-cause death. The effect of BMI with optimal normal weight (18.5-22.9 kg/m2) as reference was analyzed according to age groups [young (20-39 years), middle-aged (40-64 years), and elderly (≥65 years)] and age decades.

RESULTS

During 8.2 years, MI, HF, and all-cause death occurred in 65,607 (0.71%), 131,903 (1.42%), and 306,065 (3.30%), respectively. Associations between BMI and all outcomes were significantly modified by age (p-for-interaction < 0.001). There was a proportional increase in incident MI according to BMI in young subjects; this relationship became U-shaped in middle-aged subjects, and inversely proportional/plateauing in elderly subjects. A U-shaped relationship between BMI and incident HF was observed, but the impact of obesity was stronger in young subjects while the impact of underweight was stronger in middle-aged and elderly subjects. Meanwhile, lower BMI was associated with higher all-cause mortality in all ages, although this association was attenuated at young age, and pre-obesity was associated with the greatest survival benefit. These associations were independent of sex, smoking, physical activity, and comorbidities.

CONCLUSIONS

The impact of BMI on cardiovascular risk differs according to age. Weight loss may be recommended for younger overweight subjects, while being mildly overweight may be beneficial at old age.

Low waist circumference prior to percutaneous coronary intervention predict the risk for end-stage renal disease: a nationwide Korean population based-cohort study

BACKGROUND/AIMS

The obesity paradox has been known in end-stage renal disease (ESRD). However, the effect of body mass index (BMI) or waist circumference (WC) prior to percutaneous coronary intervention (PCI) on the development of ESRD is not clear.

METHODS

Using nationally representative data from the Korean National Health Insurance System, we enrolled 140,164 subjects without ESRD at enrolment who underwent PCI between 2010 and 2015, and were followed-up until 2017. Patients were stratified into five levels based on their baseline BMI and six levels based on their WC with 5-cm increments. BMI and WC were measured at least 2 years prior to PCI. The primary outcome was the development of ESRD.

RESULTS

During a median follow-up of 5.4 years, 2,082 (1.49%) participants developed ESRD. The underweight group (hazard ratio [HR], 1.331; 95% confidence interval [CI], 0.955 to 1.856) and low WC (< 80/< 75) (HR, 1.589; 95% CI, 1.379 to 1.831) showed the highest ESRD risk and the BMI 25 to 30 group showed the lowest ESRD risk (HR, 0.604; 95% CI, 0542 to 0.673) in all participants after adjusting for all covariates. In the subgroup analysis for diabetes mellitus (DM) duration, WC < 85/80 cm (men/women) increased ESRD risk in only the DM group (DM < 5 years and DM ≥ 5 years) compared to the reference group (85-90/80-85 of WC), but not the normal or impaired fasting glucose group.

CONCLUSION

Low WC prior to PCI showed an increased ESRD risk in patients with DM undergoing PCI as compared to those without DM.

U-Shaped Associations Between Body Weight Changes and Major Cardiovascular Events in Type 2 Diabetes Mellitus: A Longitudinal Follow-up Study of a Nationwide Cohort of Over 1.5 Million

OBJECTIVE

Despite the benefits of weight loss on metabolic profiles in patients with type 2 diabetes mellitus (T2DM), its association with myocardial infarction (MI), ischemic stroke (IS), atrial fibrillation (AF), heart failure (HF), and all-cause death remains elusive.

RESEARCH DESIGN AND METHODS

Using the National Health Insurance Service Database, we screened subjects who underwent general health checkups twice in a 2-year interval between 2009 and 2012. After identifying 1,522,241 patients with T2DM without a previous history of MI, IS, AF, and HF, we followed them until December 2018. Patients were stratified according to the magnitude of weight changes between two general health checkups: ≤ -10%, -10 to ≤ -5%, -5 to ≤5%, 5 to ≤10%, and >10%.

RESULTS

During the follow-up (median 7.0 years), 32,106 cases of MI, 44,406 cases of IS, 34,953 cases of AF, 68,745 cases of HF, and 84,635 all-cause deaths occurred. Patients with weight changes of -5 to ≤5% showed the lowest risk of each cardiovascular event. Both directions of weight change were associated with an increased cardiovascular risk. Stepwise increases in the risks of MI, IS, AF, HF, and all-cause death were noted with progressive weight gain (all P < 0.0001). Similarly, the more weight loss occurred, the higher the cardiovascular risks observed (all P < 0.0001). The U-shaped associations were consistently observed in both univariate and multivariate analyses. Explorative subgroup analyses also consistently showed a U-shaped association.

CONCLUSIONS

Both weight loss and gain >5% within a 2-year interval were associated with an increased risk of major cardiovascular events in patients with T2DM.

Diabetes Fact Sheet in Korea 2021

BACKGROUND

This study aimed to investigate the prevalence and management of diabetes mellitus, risk-factor control, and comorbidities among Korean adults.

METHODS

We conducted a cross-sectional analysis of data from the Korea National Health and Nutrition Examination Survey to assess the prevalence, treatment, risk factors, comorbidities, and self-management behaviors of diabetes mellitus from 2019 to 2020. We also analyzed data from the Korean National Health Insurance Service to evaluate the use of antidiabetic medications in people with diabetes mellitus from 2002 through 2018.

RESULTS

Among Korean adults aged 30 years or older, the estimated prevalence of diabetes mellitus was 16.7% in 2020. From 2019 through 2020, 65.8% of adults with diabetes mellitus were aware of the disease and treated with antidiabetic medications. The percentage of adults with diabetes mellitus who achieved glycosylated hemoglobin (HbA1c) <6.5% was 24.5% despite the increased use of new antidiabetic medications. We found that adults with diabetes mellitus who achieved all three goals of HbA1c <6.5%, blood pressure (BP) <140/85 mm Hg, and low-density lipoprotein cholesterol <100 mg/dL were 9.7%. The percentage of self-management behaviors was lower in men than women. Excess energy intake was observed in 16.7% of adults with diabetes mellitus.

CONCLUSION

The prevalence of diabetes mellitus among Korean adults remained high. Only 9.7% of adults with diabetes mellitus achieved all glycemic, BP, and lipid controls from 2019 to 2020. Continuous evaluation of national diabetes statistics and a national effort to increase awareness of diabetes mellitus and improve comprehensive diabetes care are needed.