2014 clinical practice guidelines for overweight and obesity in Korea

Association between weight perception and perceived stress among Korean adults from the Korea National Health and Nutrition Examination Survey

Although several studies showed a correlation between weight perception and depression, the association between weight perception and perceived stress is unclear. This study explored this association using the Korea National Health and Nutrition Examination Survey with 37,022 participants. Participants were grouped based on how they perceived their body versus real body mass index (BMI) and waist circumference: accurate, underperception, or overperception. Stress was assessed through a questionnaire. The logistic regression analysis was performed, and odds ratio (OR) with 95% confidence intervals (CIs) was presented. The results showed a correlation between overperception and higher perceived stress. This correlation was especially apparent in women with significant OR and 95% CIs of 1.15 (1.07-1.23) for BMI and 1.15 (1.07-1.23) for waist circumference. In the subgroup analysis according to the real obese status, all misperceptions were associated with higher perceived stress in normal participants. In comparison, underperception showed a correlation with lower perceived stress in obese participants. The results suggest weight perception as a potential marker for many stress-related diseases and an important factor in treating mental disorders. Further research is needed to understand the relationship between stress and weight perception.

Dynamic Changes in Metabolic Status Are Associated With Risk of Ocular Motor Cranial Nerve Palsies

BACKGROUND

To investigate whether recovery from or development of metabolic syndrome (MetS) in a population is associated with an altered risk for ocular motor cranial nerve palsy (CNP).

METHODS

This cohort study included 4,233,273 adults without a history of ocular motor cranial nerve palsy (ocular motor CNP) who underwent 2 consecutive biennial health screenings provided by the Korean National Health Insurance System between 2009 and 2011. They were followed up until December 31, 2018. Participants were categorized into a MetS-free, MetS-developed, MetS-recovered, or MetS-chronic group. A multivariable Cox proportional hazard regression model was used. Model 3 was adjusted for age, sex, smoking status, alcohol consumption, and physical activity.

RESULTS

Compared with the MetS-free group, the MetS-chronic group had the highest risk of ocular motor CNP (hazard ratio [HR]: 1.424; 95% confidential interval [CI]: 1.294-1.567, Model 3), followed by the MetS-developed group (HR: 1.198, 95% CI: 1.069-1.343), and the MetS-recovered group (HR: 1.168, 95% CI: 1.026-1.311) after adjusting for potential confounders. The hazard ratio of ocular motor CNP in men with chronic MetS was 1.566 (95% CI, 1.394-1.761) while that of women with chronic MetS was 1.191 (95% CI, 1.005-1.411). Among age groups, those in their 30s and 40s showed the highest association between dynamic MetS status and ocular motor CNP.

CONCLUSIONS

In our study, recovering from MetS was associated with a reduced risk of ocular motor CNP compared with chronic MetS, suggesting that ocular motor CNP risk could be managed by changing MetS status.

Tuberculosis survivors and the risk of cardiovascular disease: analysis using a nationwide survey in Korea

Background

Although the association between tuberculosis (TB) and cardiovascular disease (CVD) has been reported in several studies and is explained by mechanisms related to chronic inflammation, few studies have comprehensively evaluated the association between TB and CVD in Korea.

Methods

Using the Korea National Health and Nutrition Survey, we classified individuals according to the presence or absence of previous pulmonary TB was defined as the formal reading of a chest radiograph or a previous diagnosis of pulmonary TB by a physician. Using multivariable logistic regression analyses, we evaluated the association between the 10-year atherosclerotic cardiovascular disorder (ASCVD) risk and TB exposure, as well as the 10-year ASCVD risk according to epidemiological characteristics.

Results

Among the 69,331 participants, 4% (n = 3,101) had post-TB survivor group. Comparing the 10-year ASCVD risk between the post-TB survivor and control groups, the post-TB survivor group had an increased 10-year ASCVD risk in the high-risk group (40.46% vs. 24.00%, P < 0.001). Compared to the control group, the intermediate- and high-risk groups had also significantly increased 10-year ASCVD risks (odds ratio [OR] 1.14, 95% confidence interval [CI] 1.04-1.23 and OR 1.69, 95% CI 1.59-1.78, respectively) in the post-TB survivor group. In the association of CVD among post-TB survivors according to epidemiologic characteristics, age [adjusted OR (aOR) 1.10, 95% CI 1.07-1.12], current smoking (aOR 2.63, 95% CI 1.34-5.14), a high family income (aOR 2.48, 95% CI 1.33-4.62), diabetes mellitus (aOR 1.97, 95% CI 1.23-3.14), and depression (aOR 2.06, 95% CI 1.03-4.10) were associated with CVD in the post-TB survivor group.

Conclusions

Our study findings suggest a higher 10-year ASCVD risk among TB survivors than healthy participants. This warrants long-term cardiovascular monitoring and management of the post-TB population.

Glycemic Control and Oral Health Outcomes in Patients With Diabetes: Insights From a Nationwide Korean Survey

BACKGROUND

Diabetes is recognized as a risk factor for various inflammatory conditions, including periodontitis. There exists a bidirectional relationship between glycemic control and oral health in individuals with diabetes. This study aimed to analyze the link between glycemic control and oral health status among Korean patients with diabetes.

METHODS

Using data from a population-based nationwide survey conducted between 2007 and 2019, we identified 70,554 adults with diabetes-related information. The study population included 9,090 individuals diagnosed with diabetes and 61,164 healthy controls. The association between glycemic control, defined by mean glycated hemoglobin (HbA1c) values, and various oral health measures, such as tooth brushing frequency, periodontitis, denture wearing, Decayed, Missing, and Filled Teeth (DMFT) index, number of remaining teeth, and past-year dental clinic visits, was evaluated using multivariate logistic regression analyses.

RESULTS

Compared to the control group, patients with diabetes exhibited a higher prevalence of periodontitis (88.6% vs. 73.3%), complete dentures (5.0% vs. 1.5%), and elevated DMFT index (33.2% vs. 26.7%) (all P < 0.001). Multivariate analyses revealed significant associations between diabetes and several oral health factors: denture status (No denture: adjusted odds ratio [aOR], 0.784; 95% confidence interval [CI], 0.627-0.979), and having fewer permanent teeth (0-19) (aOR, 1.474; 95% CI, 1.085-2.003). Additionally, a positive correlation was found between higher HbA1c levels and the risk of having fewer remaining teeth (0-19) (HbA1c < 6.5%: aOR, 1.129; 95% CI, 0.766-1.663; 6.5% ≤ HbA1c < 8.0%: aOR, 1.590; 95% CI, 1.117-2.262; HbA1c ≥ 8%: aOR, 1.910; 95% CI, 1.145-3.186) (P for trends = 0.041).

CONCLUSION

We found a positive association between diabetes and poor oral health, as well as a noteworthy relationship between reduced permanent teeth (≤ 19) and glycemic control. These insights emphasize the critical role of oral health management in diabetic care and underscore the importance of maintaining effective glycemic control strategies for overall health and well-being in patients with diabetes.

Proteinuria and risk of ocular motor cranial nerve palsy: a nationwide population-based study

Understanding the association between dipstick-detected proteinuria and oculomotor cranial nerve palsy (CNP) could have significant implications for understanding the mechanism of CNP development and for developing preventive strategies against CNP development in patients with proteinuria. This study aimed to determine the relationship between dipstick-determined proteinuria and ocular motor CNP using National Sample Cohort (NSC) database from Korea's National Health Insurance Service (NHIS). A nationwide population-based cohort study was conducted using data from the NSC database of Korea's NHIS. These data were collected from 2009 to 2018. A one-year time lag was established to prevent a situation in which the causal link was inverted. Participants aged 20 years or more who were diagnosed with proteinuria in 2009 were included. Individuals with specific pre-existing CNP, missing data, and those who were newly diagnosed with CNP or who died within one year of being tested were excluded. The study population was classified into six groups according to the degree of proteinuria (negative, trace, or between 1 + and 4 +) based on the urine dipstick test. A Cox proportional hazard regression analysis was performed to determine the linkage between the degree of proteinuria and ocular motor CNP. A total of 5,807 (0.14% of subjects) with ocular motor CNP were assigned to the ocular motor CNP group and 4,047,205 subjects were assigned to the control group. After full adjustment of comorbidities, hazard ratios (HRs) for 1 + , 2 + , 3 + and 4 + proteinuria groups were 1.449 (95% confidence interval [CI] 1.244-1.687), 2.081 (1.707-2.538), 1.96 (1.322-2.904), and 3.011 (1.507-6.014), respectively, for developing ocular motor CNP compared to the proteinuria-negative group. In subgroup analysis, the HR of patients with proteinuria for the development of ocular motor CNP was higher in the younger age group (less than 40 years) (P = 0.0242) and the group with DM (P = 0.04). Our population-based cohort study demonstrated a significant association between proteinuria and the incidence of CNP, suggesting that urine protein level could be a new clinical marker for predicting the development of CNP.

Risk of Depression according to Cumulative Exposure to a Low-Household Income Status in Individuals with Type 2 Diabetes Mellitus: A Nationwide Population- Based Study

BACKGRUOUND

We aimed to identify the risk of incident depression according to cumulative exposure to a low-household income status in individuals with type 2 diabetes mellitus (T2DM).

METHODS

For this retrospective longitudinal population-based cohort study, we used Korean National Health Insurance Service data from 2002 to 2018. Risk of depression was assessed according to cumulative exposure to low-household income status (defined as Medical Aid registration) during the previous 5 years among adults (aged ≥20 years) with T2DM and without baseline depression who underwent health examinations from 2009 to 2012 (n=2,027,317).

RESULTS

During an average 6.23 years of follow-up, 401,175 incident depression cases occurred. Advance in cumulative number of years registered for medical aid during the previous 5 years from baseline was associated with an increased risk of depression in a dose-dependent manner (hazard ratio [HR], 1.44 [95% confidence interval (CI), 1.38 to 1.50]; HR, 1.40 [95% CI, 1.35 to 1.46]; HR, 1.42, [95% CI, 1.37 to 1.48]; HR, 1.46, [95% CI, 1.40 to 1.53]; HR, 1.69, [95% CI, 1.63 to 1.74] in groups with 1 to 5 exposed years, respectively). Insulin users exposed for 5 years to a low-household income state had the highest risk of depression among groups categorized by insulin use and duration of low-household income status.

CONCLUSION

Cumulative duration of low-household income status, defined as medical aid registration, was associated with an increased risk of depression in a dose-response manner in individuals with T2DM.

Association of weight changes with SARS-CoV-2 infection and severe COVID-19 outcomes: A nationwide retrospective cohort study

BACKGROUND

Obesity is a risk factor for COVID-19. However, it is unknown whether weight changes can alter this risk. We investigated the association of weight changes with SARS-CoV-2 infection and acute severe COVID-19 outcomes occurring within two months of the infection.

METHODS

We used 6.3 million nationwide cohort. The body weight was classified as follows: (1) underweight, body mass index (BMI) < 18.5 kg/m2; (2) normal, BMI 18.5-22.9 kg/m2; (3) overweight, BMI 23-24.9 kg/m2; (4) obese, BMI≥ 25 kg/m2. Weight changes were defined by comparing the classification of body weight during the health screening period I and II. The outcomes were SARS-CoV-2 infection and severe COVID-19 outcomes within two months after the infection. The association was evaluated using multivariable-adjusted logistic regression. The following covariates were adjusted: age, sex, household income, cigarette smoking, alcohol consumption, physical activity, hypertension, diabetes mellitus, dyslipidemia, Charlson comorbidity index score, and dose of all COVID-19 vaccinations prior to SARS-CoV-2 infection.

RESULTS

Of the 2119,460 study participants, 184,204 were infected with SARS-CoV-2. Weight gain showed a higher risk of SARS-CoV-2 infection in underweight to normal and normal to overweight groups. Conversely, weight loss showed a lower risk of SARS-CoV-2 infection in normal to underweight, overweight to underweight, overweight to normal, obese to normal, and obese to overweight groups. In addition, weight gain revealed a higher risk of severe COVID-19 outcomes, whereas weight loss showed a lower risk of severe COVID-19 outcomes.

CONCLUSION

This study found that weight loss and gain are associated with a lower and higher risk of both SARS-CoV-2 infection and severe COVID-19 outcomes, respectively. Healthy weight management may be beneficial against the risk of COVID-19.

Clinical implications of changes in metabolic syndrome status after kidney transplantation: a nationwide prospective cohort study

BACKGROUND

Metabolic syndrome (MetS) is prevalent in patients with end-stage kidney disease, and kidney transplantation is expected to modify the metabolic status. However, whether changes in metabolic status at the time of transplantation affect recipient outcomes remains unclear.

METHODS

We analyzed 4187 recipients registered in a nationwide prospective cohort from 2014 to 2020. MetS was defined as the presence of three or more components of the metabolic syndrome. Patients were classified based on the pre- and post-transplant MetS status: MetS-free, MetS-developed, MetS-recovered and MetS-persistent. Study outcomes were occurrence of death-censored graft loss and a composite of cardiovascular events and death.

RESULTS

Among recipients without pre-transplant MetS, 19.6% (419/2135) developed post-transplant MetS, and MetS disappeared in 38.7% (794/2052) of the recipients with pre-transplant MetS. Among the four groups, the MetS-developed group showed the worst graft survival rate, and the MetS-persistent group had a poorer composite event-free survival rate. Compared with the MetS-free group, the MetS-developed group was associated with an increased risk of graft loss [adjusted hazard ratio (aHR) 2.35; 95% confidence interval (CI) 1.17-4.98] and the risk of graft loss increased with increasing numbers of dysfunctional MetS components. MetS-persistent was associated with increased risks of cardiovascular events and death (aHR 2.46; 95% CI 1.12-5.63), but changes in the number of dysfunctional MetS components was not.

CONCLUSION

Kidney transplantation significantly alters the metabolic status. Newly developed MetS after transplantation was associated with an increased risk of graft loss, whereas persistent MetS exposure before and after transplantation was associated with increased risks cardiovascular events and patient survival.

Sex difference in the age-related decline of global longitudinal strain of left ventricle

Global longitudinal strain (GLS) is a valuable indicator of subclinical myocardial dysfunction. Whether the effect of aging on subclinical left ventricular dysfunction is sex-specific is not well documented. This study aimed to identify age-related changes in GLS according to sex in patients with a normal left ventricular ejection fraction (LVEF). In this cross-sectional, single-center cohort study in Korea, participants who underwent GLS measurement using 2D speckle-tracking echocardiography were retrospectively reviewed, and participants with normal LVEF (≥ 55%) without documented cardiovascular disease were included. Reduced GLS was defined as absolute values below 18%. Of 682 study participants (mean age, 58; female, 51.5%), 209 (30.6%) had reduced GLS. Females with reduced GLS were older than those with normal GLS (68 vs. 58 years, P < 0.001); with no difference of age in males (55 vs. 57 years; P = 0.265). Univariate analysis showed age to correlate significantly with reduced GLS only in female (r =  - 0.364; P < 0.001). In multivariable analysis, female > 66 years old had significantly higher risk of reduced GLS (Odds ratio 2.66; 95% CI 1.22-5.76; P = 0.014). In participants with normal LVEF, GLS decreased with age in females but not in males. Particularly, females aged 66 years and older had a significantly higher risk of reduced GLS. These findings suggest that GLS could be a valuable parameter for assessing subclinical cardiac dysfunction, especially in older females.

Mediators of the Effect of Obesity on Stroke and Heart Disease Risk: Decomposing Direct and Indirect Effects

BACKGROUND

The prevalence of overweight and obesity are well known risk factors of atherosclerotic cardiovascular disease (ASCVD). We aimed to examine the association between body mass index (BMI) and ASCVD over a 23-year follow-up in young adults. We also qualified how much of the effects of obesity on ASCVD were mediated through blood pressure, cholesterol, and glucose.

METHODS

Data are from the Korean Life Course Health Study, a cohort study of 226,955 Korean young adults aged 20-39. At baseline, the participants undertook routine health assessments where their BMI was measured in 1992-1994; and the metabolic mediators including systolic blood pressure (SBP), fasting serum glucose (FSG), and total cholesterol (TC) were re-measured in 2002-2004. The main outcomes of the study include incident events of ischemic heart disease (IHD), stroke, and ASCVD between 2005 and 2015. Cox proportional model was used to calculate adjusted hazard ratios (HRs) for ASCVD.

RESULTS

In both men and women, the direct effect of BMI on ASCVD was greater than the indirect effect. The percentage of excess HR of BMI mediated by all of the metabolic mediators, including SBP, FSG, and TC, was 45.7% for stroke and 18.7% for IHD in men and 27.5% for stroke and 17.6% for IHD in women.

CONCLUSION

High BMI in young adults increases the risk of metabolic mediators in their middle age, and metabolic mediators explain the adverse effects of high BMI on stroke risk than IHD risk.

Factors associated with the combination of general and abdominal obesity in middle-aged and older Korean women: a cross-sectional study

BACKGROUND

To identify factors associated with general and abdominal obesity in middle-aged and older Korean women based on the biopsychosocial model.

METHODS

Data from 4,076 women aged ≥45 years who participated in the Korea National Health and Nutrition Examination Survey from 2015 to 2020 were analyzed. Complex sampling analysis was performed using IBM SPSS ver. 26.0.

RESULTS

The combination of general and abdominal obesity was positively associated with age ≥65 years, postmenopausal status, and without breastfeeding experience among biomedical factors; depressive symptoms and prolonged (≥8 hours a day) sedentary behavior among psychosocial factors; and an educational level lower than middle or high school graduation and the first and second income quantiles among biosocial factors.

CONCLUSION

Healthcare providers in communities and public societies should screen for risk factors for the combination of general and abdominal obesity while considering non-modifiable biomedical (e.g., age) and biosocial factors (e.g., educational level). In addition, intervention strategies should be developed by considering modifiable psychosocial factors such as sedentary behavior.

The insufficiency of a simple stress question in assessing stress for chronic daily headache in clinical practice

BACKGROUND

In managing chronic daily headaches (CDH), a comprehensive approach is necessary to evaluate stress, a closely linked factor. However, limited time and costs often lead to the use of a simple stress question in clinical settings. This study aims to assess the validity of using a simple stress question for CDH patients and explore its implications for clinical practice.

METHODS

We recruited 103 patients with CDH who completed structured self-administered questionnaires, including a simple stress question ("Have you had any stress or concerns in the last 4 weeks?") and validated Korean versions of questionnaires for depression, anxiety, insomnia, and the Brief Encounter Psychosocial Instrument (BEPSI). A headache specialist conducted clinical interviews. The stress group consisted of patients who acknowledged overt stress (answering "yes" to the simple question) and covert stress (initially answering "no" but later admitting during the interview). Results showed no statistical difference between the subgroups, so they were combined as the "acknowledged stress" group.

RESULTS

Out of 103 patients, 54.4% had chronic migraine, 45.6% had chronic tension-type headache, and 66 patients (64.1%) acknowledged experiencing stress. No significant differences were found in demographic and clinical characteristics, BEPSI stress assessment, or depression, anxiety, and insomnia profiles between patients with overt stress (n = 51) and covert stress (n = 15). The average BEPSI score was 2.3 ± 0.9, with 45.6% of patients exceeding the criteria (>2.4). Two (5.4%) patients in denial of stress had scores above the BEPSI criteria. Among patients below the criteria of BEPSI, 21 acknowledged stress, while 35 denied stress, with no significant differences observed.

CONCLUSIONS

This study suggests the limitations of relying solely on a simple stress question for assessing stress in patients with CDH in clinical practice. It is possible to encounter covert stress, include individuals who do not exhibit noticeable stress, and misclassify stress levels. To overcome these limitations, it is necessary to foster a supportive environment for open communication on stress and implement a comprehensive assessment strategy when needed.

Low Household Income Status and Death from Pneumonia in People with Type 2 Diabetes Mellitus: A Nationwide Study

BACKGRUOUND

We explored the risk of death from pneumonia according to cumulative duration in low household income state (LHIS) among adults with type 2 diabetes mellitus (T2DM).

METHODS

Using Korean National Health Insurance Service data (2002 to 2018), the hazards of mortality from pneumonia were analyzed according to duration in LHIS (being registered to Medical Aid) during the 5 years before baseline (0, 1-4, and 5 years) among adults with T2DM who underwent health examinations between 2009 and 2012 (n=2,503,581). Hazards of outcomes were also compared in six groups categorized by insulin use and duration in LHIS.

RESULTS

During a median 7.18 years, 12,245 deaths from pneumonia occurred. Individuals who had been exposed to LHIS had higher hazards of death from pneumonia in a dose-response manner (hazard ratio [HR], 1.726; 95% confidence interval [CI], 1.568 to 1.899 and HR, 4.686; 95% CI, 3.948 to 5.562 in those exposed for 1-4 and 5 years, respectively) compared to the non-exposed reference. Insulin users exposed for 5 years to LHIS exhibited the highest outcome hazard among six groups categorized by insulin use and duration in LHIS.

CONCLUSION

Among adults with T2DM, cumulative duration in LHIS may predict increased risks of mortality from pneumonia in a graded dose-response manner. Insulin users with the longest duration in LHIS might be the group most vulnerable to death from pneumonia among adults with T2DM.

Metabolic dysfunction-associated fatty liver disease and the risk of hepatocellular carcinoma

Background & Aims

The metabolic dysfunction-associated fatty liver disease (MAFLD) is a new inclusive term proposed to replace non-alcoholic fatty liver disease (NAFLD). We analysed whether hepatocellular carcinoma (HCC) risk differs by MAFLD or NAFLD status in a large sample of asymptomatic adults.

Methods

A cohort comprising 73,691 adults were followed up for the development of HCC. NAFLD was diagnosed among participants without other liver diseases (n = 65,992).

Results

Participants with MAFLD showed higher incidence of HCC than those without MAFLD (0.37 and 0.24 per 1,000 person-years, respectively; p = 0.006). However, MAFLD was not an independent factor associated with HCC in multivariable adjusted analysis (hazard ratio [HR] 1.21; 95% CI 0.92-1.60). When stratified according to presence of other liver diseases, MAFLD was not associated with HCC in participants with other liver diseases. In participants without other liver diseases, both MAFLD (adjusted HR 1.84; 95% CI 1.09-3.11) and NAFLD (adjusted HR 1.71; 95% CI 1.01-2.90) were independent factors associated with HCC. When stratified according to NAFLD and MAFLD status, there was no HCC development among participants with NAFLD only during 8,936 person-years of follow-up, but this NAFLD-only group comprised 3.4%, and the majority of participants with hepatic steatosis fulfilled both NAFLD and MAFLD criteria.

Conclusions

In patients with other chronic liver diseases, the presence of MAFLD is not independently associated with an increased risk of HCC. For those without other chronic liver diseases, MAFLD largely overlaps with NAFLD and is associated with an increased risk of HCC.

Impact and Implications

This study investigated the usefulness of newly proposed nomenclature, metabolic dysfunction-associated fatty liver disease (MAFLD), over non-alcoholic fatty liver disease (NAFLD), in terms of predicting hepatocellular carcinoma. In patients with other chronic liver diseases, the presence of MAFLD is not independently associated with an increased risk of HCC. However, for those without chronic liver disease, MAFLD largely overlaps with NAFLD and is associated with an increased risk of HCC.

Association Between Oral Health and Airflow Limitation: Analysis Using a Nationwide Survey in Korea

BACKGROUND

Although poor oral health is a common comorbidity in individuals with airflow limitation (AFL), few studies have comprehensively evaluated this association. Furthermore, the association between oral health and the severity of AFL has not been well elucidated.

METHODS

Using a population-based nationwide survey, we classified individuals according to the presence or absence of AFL defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity < 0.7. Using multivariable logistic regression analyses, we evaluated the association between AFL severity and the number of remaining teeth; the presence of periodontitis; the Decayed, Missing, and Filled Teeth (DMFT) index; and denture wearing.

RESULTS

Among the 31,839 participants, 14% had AFL. Compared with the control group, the AFL group had a higher proportion of periodontitis (88.8% vs. 79.4%), complete denture (6.2% vs. 1.6%), and high DMFT index (37.3% vs. 27.8%) (P < 0.001 for all). In multivariable analyses, denture status: removable partial denture (adjusted odds ratio [aOR], 1.12; 95% confidence interval [95% CI], 1.04-1.20) and complete denture (aOR, 1.52; 95% CI, 1.01-2.05), high DMFT index (aOR, 1.13; 95% CI, 1.02-1.24), and fewer permanent teeth (0-19; aOR, 1.32; 95% CI, 1.12-1.52) were significantly associated with AFL. Furthermore, those with severe to very severe AFL had a significantly higher proportion of complete denture (aOR, 2.41; 95% CI, 1.11-3.71) and fewer remaining teeth (0-19; aOR, 2.29; 95% CI, 1.57-3.01).

CONCLUSION

Denture wearing, high DMFT index, and fewer permanent teeth are significantly associated with AFL. Furthermore, a reduced number of permanent teeth (0-19) was significantly related to the severity of AFL. Therefore, physicians should pay attention to oral health in managing patients with AFL, such as chronic obstructive pulmonary disease.

Cholecystectomy increases the risk of metabolic syndrome in the Korean population: a longitudinal cohort study

Background

Cholecystectomy is a common surgical procedure to treat symptomatic gallstones; however, the long-term outcomes after cholecystectomy are unknown. Therefore, we aimed to investigate whether incident metabolic syndrome (MetS) is associated with cholecystectomy through a large, population-based, longitudinal study.

Methods

Subjects aged ≥20 years who underwent cholecystectomy from 2010 to 2014 (n=76,485) and controls (n=76,485), matched for age and sex, were identified from the Korean National Health Insurance Corporation. Cox proportional hazards analyses were performed to evaluate the association between cases and incident MetS, and hazard ratios and 95% confidence intervals (CIs) were calculated.

Results

A total of 152,970 patients were included. Mean age was 52.47±12.76 years, and 50.65% of participants were male. During the follow-up period, there were 38,979 (25.48%) newly diagnosed MetS cases in the study participants. The risk of MetS in the cholecystectomy group was approximately 20% higher than that in the control group [adjusted odds ratio (OR), 1.20; 95% CI: 1.17-1.23]. In the fully adjusted models, the corresponding ORs for new-onset high waist circumference (WC), low high-density lipoprotein cholesterol (HDL-C) levels, high triglycerides (TG) levels, high blood pressure (BP), and high blood glucose levels were 1.16 (1.13-1.19), 1.19 (1.16-1.22), 1.25 (1.22-1.28), 1.27 (1.23-1.31), and 1.21 (1.18-1.24), respectively. Cholecystectomy was an independent risk factor of incident MetS, after adjusting for potential confounding factors. In the subgroup analyses, the cholecystectomy group had a higher risk of MetS than the control group in subjects without hypertension or dyslipidemia, respectively.

Conclusions

In this large, population-based study, cholecystectomy was associated with an increased risk of developing MetS, independent of other confounding factors. Therefore, careful monitoring of metabolic variables and long-term follow-up are required to evaluate MetS risk after cholecystectomy.

Regression of nonalcoholic fatty liver disease is associated with reduced risk of incident diabetes: A longitudinal cohort study

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) is potentially reversible. However, whether improvement of NAFLD leads to clinical benefits remains uncertain. We investigated the association between regression of NAFLD and the risk of incident diabetes in a longitudinal way.

METHODS

A cohort of 11,260 adults who had NAFLD at in an initial exam, had the second evaluation for NAFLD status at 1~2 years from an initial exam were followed up for incident diabetes from 2001 and 2016. NAFLD was diagnosed with abdominal ultrasound.

RESULTS

At baseline, NAFLD was regressed in 2,559 participants (22.7%). During 51,388 person-years of follow-up (median 4 years), 1,768 participants developed diabetes. The fully adjusted hazard ratio (HR) for incident diabetes in participants with regressed NAFLD compared to those with persistent NAFLD was 0.81 [95% confidence interval (CI) 0.72-0.92]. When assessed by NAFLD severity, among participants with a low NAFLD fibrosis score (NFS) (< -1.455), participants with regressed NAFLD had a lower risk of incident diabetes than those with persistent NAFLD (HR 0.77, 95% CI 0.68-0.88). However, in participants with an intermediate to high NFS (≥ -1.455), the risk of incident diabetes was not different between NAFLD regression and persistence groups (HR 1.12, 95% CI 0.82-1.51).

CONCLUSIONS

Regression of NAFLD was associated with decreased risk of incident diabetes compared to persistent NAFLD. However, the benefit was evident only for NAFLD patients with low NFS. This suggests that early intervention for NAFLD, before advanced fibrosis is present, may maximize the metabolic benefit from NAFLD regression.

Alcohol consumption and the risk of new-onset uterine leiomyomas: a nationwide population-based study in 2.5 million Korean women aged 20 to 39 years

BACKGROUND

Uterine leiomyomas are the most common benign tumors in women of childbearing age. Although there are several studies reporting the positive association of drinking alcohol with the incidence of uterine leiomyomas, studies targeting Korean women are lacking.

OBJECTIVE

This study aimed to investigate the association between alcohol consumption and the risk of new-onset uterine leiomyomas in Korean women of early reproductive-age.

STUDY DESIGN

This was a retrospective nationwide population-based cohort study using the Korean National Health Insurance Service database. Participants comprised 2,512,384 asymptomatic Korean women aged 20 to 39 years who underwent a national health examination from 2009 to 2012. The follow-up period was from the date of the first national health examination to the date of diagnosis of new-onset uterine leiomyomas or December 2018 if no uterine leiomyomas were detected. The diagnosis of uterine leiomyomas required 2 outpatient records within a year or 1 inpatient record of International Classification of Diseases, Tenth Revision (ICD-10) codes of uterine leiomyomas (D25) in the Korean National Health Insurance Service. Exclusion criteria were previously diagnosed uterine leiomyomas during the screening period (January 2002 to the date of first health examination) or uterine leiomyoma diagnosis within 1 year of baseline examination. The associations of alcohol consumption, amount drunk per drinking session, and sustained drinking over time with the risk of new-onset uterine leiomyomas were investigated.

RESULTS

Approximately 6.1% of women aged 20 to 39 years were diagnosed with uterine leiomyomas after an average of 4.3 years. Alcohol consumption was associated with an increased incidence of new-onset uterine leiomyomas of 12% to 16% (hazard ratio, 1.12; 95% confidence interval, 1.11-1.14 for mild-to-moderate drinkers; hazard ratio, 1.16; 95% confidence interval, 1.12-1.20 for heavy drinkers). Drinking ≥1 days per week was associated with increased risk of uterine leiomyomas (hazard ratio, 1.11; 95% confidence interval, 1.10-1.12 for drinking 1 day per week; hazard ratio, 1.15; 95% confidence interval, 1.12-1.17 for drinking ≥3 days per week), and the association increased proportionately to the amount of alcohol consumed per drinking session (hazard ratio, 1.17; 95% confidence interval, 1.15-1.19 for ≥7 glasses per drinking session). Women who also reported alcohol consumption in the questionnaire administered 2 years later (sustained drinkers) exhibited a 20% increased risk of new-onset uterine leiomyomas (hazard ratio, 1.20; 95% confidence interval, 1.17-1.22) compared with women who answered that they did not drink alcohol at both times (sustained nondrinkers). In women who discontinued drinking, the risk was 3% (hazard ratio, 1.03; 95% confidence interval, 1.01-1.06), whereas in women who became drinkers, the risk was 14% (hazard ratio, 1.14; 95% confidence interval, 1.11-1.16).

CONCLUSION

Having an alcohol drinking habit, the amount of alcohol consumed per drinking session, and sustained drinking over 2 years were significantly associated with the risk of new-onset uterine leiomyomas. Avoiding or discontinuing drinking could lower the risk of new-onset uterine leiomyomas in early reproductive-age women.

Does Maintained Medical Aid Coverage Affect Healthy Lifestyle Factors, Metabolic Syndrome-Related Health Status, and Individuals' Use of Healthcare Services?

Concerns about the moral hazards and usage of universal health insurance require examination. This study aimed to analyze changes in lifestyle, metabolic syndrome-related health status, and individuals' tendency to use healthcare services according to changes in the eligibility status of medical aid recipients. This paper reports a retrospective cohort study that involved analyzing data from 2366 medical aid recipients aged 40 years or older who underwent national health screenings in 2012 and 2014. Of the recipients, 1606 participants continued to be eligible for medical aid (the "maintained" group) and 760 changed from being medical aid recipients to National Health Insurance (NHI) enrollees (the "changed" group). Compared to the "changed" group, the "maintained" group was less likely to quit smoking, more likely to begin smoking, less likely to reduce binge drinking to moderate drinking, and had a significant increase in blood glucose and waist circumference. Annual total medical expenses also increased significantly in the "maintained" group. Since the mere strengthening of healthcare coverage may lead to moral hazards and the failure to link individuals' tendency to use healthcare services and outcomes, establishing mechanisms is necessary to educate people about the health-related outcomes of maintaining a healthy lifestyle and ensure the appropriate use of healthcare services.

The risk of colorectal cancer according to obesity status at four-year intervals: a nationwide population-based cohort study

Obesity is a risk factor for colorectal cancer. However, the effect of body weight change on colorectal cancer is uncertain. This study aimed to investigate the relationship between difference in body mass index and the risk of colorectal cancer. In this nationwide population-based cohort study, participants of the national cancer screening program in 2005 and 2009 were enrolled. Difference of body mass index was calculated from screening data from 2005 and 2009. Participants were divided into four groups according to direction of obesity status: non-obese/non-obese, non-obese/obese, obese/non-obese, and obese/obese. The effect of differences in body mass index on colorectal cancer was analyzed. Among 3,858,228 participants, 47,894 (1.24%) participants were newly diagnosed with colorectal cancer during the 9.2 years of follow-up. The incidence of colorectal cancer was higher in the obese/obese group than the non-obese/non-obese group (hazard ratio = 1.08 [1.06-1.11], P trend < 0.001). The men in the obese/obese group had a higher risk of colon cancer than women (hazard ratio = 1.13 [1.10-1.17] in men, and hazard ratio = 1.04 [1.01-1.18] in women, P = 0.001). Persistent obesity was associated with a higher risk of incidence of colorectal cancer.

Association between the fatty liver index and the risk of fracture among individuals over the age of 50 years: a nationwide population-based study

Background and purpose

The association between fatty liver and fracture risk has not been firmly established. In this study, we investigated the relationship between the fatty liver index (FLI) and the incidence of fractures among individuals ≥50 years of age, using a nationwide population-based cohort.

Methods

Data from the Korean National Health Insurance System between January 2009 and December 2019 were analyzed using the Cox proportional hazards model. Fatty liver status was defined using FLI. Newly diagnosed fractures were identified based on insurance claim data.

Results

Among the 3,384,457 individuals who met our inclusion criteria over the study period, 444,203 cases of incident fractures were identified over a median follow-up of 10.3 years. On multivariate analysis, the risk of fracture was significantly higher among individuals with a higher FLI score compared to those with an FLI<30, with adjusted hazard ratio [aHR] and 95% confidence interval [CI] as follows: FLI 30-59 group, aHR 1.04 and 95% CI 1.03-1.05; and FLI ≥60 group, aHR 1.12 and 95% CI 1.10-1.13. A higher FLI was associated with a greater risk of hip (aHR 1.23 and 1.52 for the FLI 30-59 and FLI ≥60 group, respectively) and vertebral fracture (aHR 1.08 and 1.16 for the FLI 30-59 and FLI≥60 group, respectively). The association between the risk for fracture and FLI ≥60 was prominent for non-obese than obese individuals (aHR 1.25 and 95% CI, 1.22-1.27 versus 1.06 and 1.05-1.08, respectively).

Conclusions

A high FLI is associated with an increased risk of hip and vertebral fractures among individuals ≥50 years of age, suggestive of an association between a higher FLI and osteoporotic fractures.

Relationship between a Low-Carbohydrate, High-Fat Diet and Risk of Metabolic Syndrome in Korean Women

Background

Prevalence of metabolic syndrome with aging is higher in women than in men, and it increases after menopause. Interventions to reduce the risk of metabolic syndrome in women are important. A low-carbohydrate, high-fat diet is effective in weight loss and improvement cardiovascular risk factors including abdominal circumference, blood pressure, and blood lipid profile. We aimed to determine the relationship between a low-carbohydrate, high-fat diet and the risk of metabolic syndrome in Korean women.

Methods

This cross-sectional study was conducted using secondary data from the 2014-2018 Korean National Health and Nutrition Examination Survey. Overall, 8,222 women aged >19 yr were included. The effect of a low-carbohydrate, high-fat diet on the risk of metabolic syndrome was analyzed by multiple logistic regression analysis using a complex sampling procedure.

Results

The diet significantly reduced the likelihood of metabolic syndrome development (P=0.044). In addition, regardless of the fat type, the diet significantly reduced the likelihood of low high-density lipoprotein cholesterolemia (low-carbohydrate, high-total fat, P=0.013; low-carbohydrate, high-unsaturated fat, P=0.006; low-carbohydrate, high-saturated fat, P=0.006).

Conclusion

A low-carbohydrate, high-fat diet is an important intervention that can reduce the risk of metabolic syndrome, and the reduced consumption of carbohydrates can decrease the risk of low high-density lipoprotein cholesterolemia regardless of fat type. Therefore, it is necessary to actively explore the potential of this diet, targeting Asians, including Koreans.

Histological subtypes of hepatocellular carcinoma: Their clinical and prognostic significance

Assigning a hepatocellular carcinoma (HCC) to an appropriate subtype is important because this guarantees the diagnosis and treatment and allows decisions regarding the prognosis of the patient. HCC subtyping is usually based on the World Health Organization (WHO) classification and the 2019 fifth edition is the latest version. However, the WHO classification system is still in evolution and has limited clinical relevance. We aimed to evaluate the clinical relevance of HCC subtyping and to reappraise some of the major subtypes of HCC. Our archived cases (n = 589) were reclassified according to the 2019 WHO system. The percentage of each subtype was mostly similar to that in the WHO classification. However, on the contrary to the 2019 WHO system, clear cell type HCC was associated with more frequent recurrence or metastasis. Meanwhile, macrotrabecular massive HCC was related to poor prognosis as demonstrated in the 2019 WHO system and should be described in the pathology report. For steatohepatitic HCC, there is a debate on whether it is a true subtype because the steatohepatitis morphology may or may not be present in the background liver. In our study, 44 % of steatohepatitic HCCs (n = 19/43) presented underlying steatohepatitis. Additionally, the background cirrhosis did not influence survival in the HCC patients, although the 2019 WHO system indicates the presence of cirrhosis as a poor prognostic factor. In conclusion, although it is not perfect yet, HCC subtyping based on the 2019 WHO system provides valuable information to manage patients with HCC.

Chronic physical exercise alleviates stress-associated amygdala metabolic activity in obese women: A prospective serial 18F-FDG PET/CT study

Background

Psychological stress is considered as a major risk factor for cardiovascular disease (CVD). Chronic exercise is known to reduce CVD risk partly through attenuating psychological stress. Obesity has been linked with increased levels of psychological stress. We aimed to prospectively evaluate whether physical exercise could alleviate stress-associated amygdala metabolic activity, assessed by 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in women with obesity.

Material and methods

A total of 43 participants were enrolled in this study. Twenty-three obese women were participated in a physical exercise program 5 days per week for 3 months. The exercise program consisted of aerobic exercise and resistance training. Serial 18F-FDG PET/CT was taken before the start of physical exercise program (baseline) and after finishing the program (post-exercise). A total of 20 participants who underwent 18F-FDG PET/CT for general health check-up were enrolled as non-obese control group. Brain amygdala activity (AmygA) was calculated as maximum standardized uptake value (SUVmax) of amygdala normalized to mean SUV of temporal lobe.

Results

Chronic physical exercise significantly reduced AmygA and improved body adiposity and systemic inflammation. AmygA was highest in baseline, intermediate in post-exercise, and lowest in non-obese control group (0.76 ± 0.17, 0.61 ± 0.1, 0.52 ± 0.09, p < 0.001). Furthermore, physical exercise also abrogated the association of AmygA with systemic inflammation.

Conclusions

Chronic physical exercise reduced stress-associated amygdala metabolic activity and broke its association with systemic inflammation in obese women. This study could explain the putative mechanism underlying the health beneficial effect of exercise on CVD via attenuation of stress neurobiology.

Association between non-cystic fibrosis bronchiectasis and the risk of incident dementia: A nationwide cohort study

BACKGROUND

Chronic lung diseases, such as chronic obstructive pulmonary disease or asthma, are associated with an increased risk of dementia. However, few data are available regarding the risk of dementia in individuals with bronchiectasis.

OBJECTIVES

To explore the association between bronchiectasis and the risk of incident dementia using a longitudinal population-based cohort.

METHODS

A total of 4,068,560 adults older than 50 years without previous dementia were enrolled from the Korean National Health Insurance Service database in 2009. They were followed up until the date of the diagnosis of dementia or December 31, 2020. The study exposure was the diagnosis of bronchiectasis, and the primary outcome was incident dementia comprising Alzheimer's disease and vascular dementia.

RESULTS

During the median follow-up duration of 9.3 years, the incidence of all-cause dementia was 1.6-fold higher in individuals with bronchiectasis than in those without bronchiectasis (15.0 vs. 9.3/1000 person-years, p < .001). In the multivariable Cox regression analysis, the risk of all dementia was significantly higher in individuals with bronchiectasis than in those without bronchiectasis (adjusted hazard ratio [aHR] 1.09, 95% confidence interval [CI] 1.04-1.14). In a subgroup analysis by dementia type, individuals with bronchiectasis had an increased risk of Alzheimer's disease compared to those without bronchiectasis (aHR 1.07, 95% CI 1.01-1.12); the risk of vascular dementia did not significantly differ between the two groups (aHR 1.05, 95% CI 0.90-1.21).

CONCLUSION

Bronchiectasis was associated with an increased risk of dementia, especially Alzheimer's disease.

Self-perceived Weight and Mortality in Korean Adults Based on the Korea National Health and Nutrition Examination Survey Data Linked to Cause of Death Statistics

Background

This study aimed to determine the associations between self-perceived weight, weight perception, and mortality risk among Korean adults.

Methods

Data from the 2007 to 2015 Korea National Health and Nutrition Examination Survey and the 2007 to 2019 Cause of Death Statistics were linked for this cohort study. A complex samples Cox regression analysis involving 42,453 participants (17,056 male; 25,397 female) was performed after excluding those who died within 1 year of the follow-up period, those with a history of cancer, those with cardiovascular diseases, those without body mass index (BMI) data, and those without self-perceived weight data.

Results

During 7.85 years of follow-up, the overall mortality rate was 3.8% (4.5% for male and 3.1% for female). Self-perceived thin weight status was associated with a 43% to 68% higher risk of all-cause mortality and a 2.48-times higher risk of cardiovascular mortality compared to self-perceived just right weight status after controlling for sociodemographic characteristics, health-related behaviors, underlying health status, BMI, and metabolic syndrome. After adjusting for the confounding factors, those who underestimated their weight had a 27% reduced risk of all-cause mortality than those who correctly estimated their weight. The risks of all-cause mortality and cardiovascular mortality were 2.14-times higher and 2.32-times higher, respectively, in the underweight group with an accurate weight estimation than in the normal weight group with an accurate weight estimation. However, all-cause mortality was 47% lower among participants with obesity who overestimated their weight.

Conclusion

Self-perceived thinness and accurately perceived underweight status were associated with increased risks of all-cause mortality and cardiovascular mortality among Korean adults.

Differences of Regional Fat Distribution Measured by Magnetic Resonance Imaging According to Obese Phenotype in Koreans

Background: Obesity is commonly associated with a high risk of metabolic disorders, and obesity-related metabolic abnormalities are affected by some specific obesity phenotypes, regional fat distribution, and body mass index. However, few studies have investigated the relationship between obesity phenotypes and regional fat distribution in Korean subjects. This study aimed to assess regional fat distribution by gender using magnetic resonance imaging (MRI), and to identify a link between fat distribution and metabolic disorders in Korean subjects. Methods: This study included 35 Korean subjects (20 women, 15 men) who were classified into two groups by gender, and further divided into two groups based on their obesity phenotype: a metabolically abnormal obesity (MAO) and metabolically healthy obesity (MHO) group. Fat distribution was measured using MRI. The blood parameters were measured using a commercially available kit. Results: Women in the MAO group had more risk factors for metabolic abnormalities than those in the MHO group. Serum glucose, triglyceride, and high-density lipoprotein cholesterol (HDL-C) levels were also significantly higher in women with MAO than in those with MHO. The intermuscular adipose tissue (IMAT) of women with MAO was significantly higher than that of women with MHO. Serum HDL-C level was negatively correlated with IMAT, whereas leptin showed a positive correlation with IMAT in all subjects. Conclusions: Metabolic abnormalities according to obesity phenotype posed a higher risk in women than that in men. These findings suggest that an understanding of gender differences in relation to the association between obesity and metabolic risk would be helpful to reduce the prevalence of obesity.

Weight Control Registry Using Korean Medicine: A Protocol for a Prospective Registry Study

Lifestyle and physical characteristics affect body weight, and understanding these factors improves the precision of weight loss treatment. Many obese patients in Korea are receiving Korean medicine (KM) treatment, including herbal medicine and acupuncture, for weight loss. However, the real-world data (RWD) are insufficient in terms of being longitudinal and diverse. Weight Control Registry using KM is a prospective registry study that enrolls patients receiving KM treatment for weight loss and collects RWD from multiple clinics. The patients who are eligible for this study are aged 19-65 years, receive KM weight loss treatment, understand the study objectives, and consent voluntarily. Clinical data of patient characteristics and KM treatment patterns will be regularly collected until 2026. The longitudinal accumulation of various RWD will establish a high-quality study database for KM weight loss treatment. With this study, we expect to contribute to understanding the current trend of weight loss treatment with KM and solve further questions regarding this treatment.

Association between exercise and risk of cardiovascular diseases in patients with non-cystic fibrosis bronchiectasis

BACKGROUND

Although cardiovascular comorbidities negatively impact survival in patients with bronchiectasis, there is limited evidence to recommend exercise in this population. We aimed to evaluate whether exercise habit changes are related to reduced cardiovascular disease risk and explore an optimal exercise amount.

METHODS

This study identified 165,842 patients with newly diagnosed bronchiectasis during 2010-2016 who underwent two health examinations and were followed up until December 2020. The exposure was the change in weekly habits of moderate- or vigorous-intensity physical activity between the two examinations, classified into non-exercisers and exercisers (further classified into new exercisers, exercise dropouts, and exercise maintainers). The amount of exercise was measured using metabolic equivalents of task (MET). The outcome was the incidence of myocardial infarction (MI) or stroke.

RESULTS

During a mean of 6.2 ± 2.1 follow-up years, 4,233 (2.6%) and 3,745 (2.3%) of patients with bronchiectasis had MI or stroke, respectively. Compared to non-exercisers, exercisers had a significantly lower risk of MI or stroke by 9-28% (p < 0.001 for both). Among exercisers, exercise maintainers showed the lowest risk of MI (adjusted hazard ratio [aHR], 0.72; 95% confidence interval [CI], 0.64-0.81) and stroke (aHR, 0.72; 95% CI, 0.64-0.82) compared to non-exercisers. Regarding exercise amount, a significant risk reduction was observed only in patients with bronchiectasis who exercised for ≥ 500 MET-min/wk.

CONCLUSION

Exercise was associated with a reduced risk of cardiovascular diseases in patients with bronchiectasis. In particular, the risk was lowest in exercise maintainers, and cardiovascular risk reduction was significant when exercising more than 500 MET-min/wk.

Dynapenic-abdominal obesity as an independent risk factor for chronic kidney disease in postmenopausal women: a population-based cohort study

OBJECTIVE

Low muscle strength and obesity lead to a higher risk of chronic kidney disease (CKD). Perimenopause is associated with a natural decline in muscle strength and an increase in visceral adiposity. Dynapenic obesity, which is the coexistence of low muscle strength and obesity, is expected to synergistically increase the prevalence of CKD in postmenopausal women. The aim of this study was to determine combined associations of dynapenia and obesity with CKD in postmenopausal women.

METHODS

This study used data from the Korean National Health and Nutrition Examination Survey, 2016 to 2019. The study included 4,525 postmenopausal women aged 42 to 80 years that were classified into four groups based on waist circumference (≥85 cm) and hand grip strength (<18 kg): normal, dynapenic, obese, or dynapenic-obese. According to the Kidney Disease: Improving Global Outcomes, we defined CKD as an estimated glomerular filtration rate <60 mL/min per 1.73 m2. Complex sample logistic regression models were conducted to determine the relationships among coexistence of dynapenia, abdominal obesity, and the risk of CKD.

RESULTS

Dynapenic-abdominal obese group displayed lower estimated glomerular filtration rate levels than other groups (P < 0.05 for all data). The prevalence rates of CKD were 15.5%, 7.8%, 6.2%, and 2.4% in the dynapenic-abdominal obese, dynapenic, abdominal obese, and normal groups, respectively (P < 0.001). Complex sample logistic regression analyses, after adjusting for age, height, health behaviors, and comorbidities, showed that the odds ratio for CKD with respect to dynapenic-abdominal obesity was 1.82 (95% confidence interval, 1.19-2.79) and to abdominal obesity was 1.54 (95% confidence interval, 1.07-2.22) than in the normal group.

CONCLUSIONS

This study demonstrated that dynapenic-abdominal obesity, as determined by low handgrip strength and high waist circumference values, was associated with increased risk of CKD in postmenopausal women.

Myocardial Infarction, Stroke, and All-Cause Mortality according to Low-Density Lipoprotein Cholesterol Level in the Elderly, a Nationwide Study

BACKGROUND

We assessed the myocardial infarction (MI), stroke, and all-cause death risks during follow-up according to the low-density lipoprotein cholesterol (LDL-C) levels among older adults.

METHODS

The Korean National Health Insurance Service datasets (2002 to 2020) were used for this population-based cohort study. The hazards of MI, stroke, and all-cause mortality during follow-up were analyzed according to LDL-C level in individuals aged ≥65 years without baseline cardiovascular diseases (n=1,391,616).

RESULTS

During a mean 7.55 years, 52,753 MIs developed; 84,224 strokes occurred over a mean 7.47 years. After a mean 8.50 years, 233,963 died. A decrease in LDL-C was associated with lower hazards of MI and stroke. The decreased hazard of stroke in lower LDL-C was more pronounced in statin users, and individuals with diabetes or obesity. The hazard of all-cause death during follow-up showed an inverted J-shaped pattern according to the LDL-C levels. However, the paradoxically increased hazard of mortality during follow-up in lower LDL-C was attenuated in statin users and individuals with diabetes, hypertension, or obesity. In statin users, lower LDL-C was associated with a decreased hazard of mortality during follow-up.

CONCLUSION

Among the elderly, lower LDL-C was associated with decreased risks of MI and stroke. Lower LDL-C achieved by statins in the elderly was associated with a decreased risk of all-cause death during follow-up, suggesting that LDL-C paradox for the premature death risk in the elderly should not be applied to statin users. Intensive statin therapy should not be hesitated for older adults with cardiovascular risk factors including diabetes.

Long-term efficacy of varicocele repair in middle-aged men with erectile dysfunction (ED) and low testosterone: Five cases with follow-up from 16 to 60 months

We report five cases of middle-aged men with low testosterone levels and erectile dysfunction (ED) who were successfully treated with varicocelectomy with long-term follow-up. All five patients presented to our clinic with ED. Upon initial physical examination, each patient had varicoceles on his scrotum, and two consecutive morning samplings showed testosterone levels below 400 ng/mL. Age at varicocelectomy was from 40 to 53 years. Four patients underwent microscopic subinguinal varicocelectomy, whereas one patient underwent inguinal varicocelectomy. After surgery, testosterone increased in all cases, and the normal testosterone level was maintained during follow-up (16–60 months). In addition, all cases reported improvement of ED after surgery. In our clinical cases, microscopic varicocelectomy increased serum testosterone levels and improved erectile function, and this increase and improvement continued up to a follow-up of 60 months. Varicocelectomy would be a good option to treat testosterone deficiency in men with varicocele.

Risk for Behçet's disease gauged via high-density lipoprotein cholesterol: a nationwide population-based study in Korea

Behçet’s disease (BD) is a chronic inflammatory disease. Low levels of plasma high-density lipoprotein cholesterol (HDL-C) are associated with Crohn’s disease, another chronic inflammatory disease. However, the effects of low HDL-C levels on BD are unclear. We investigated the effects of HDL-C levels, and variability therein, on the risk for BD. We used the Korean National Health Insurance System database to identify 5,587,754 adults without a history of BD who underwent ≥ 3 medical examinations between 2010 and 2013. Mean HDL-C levels at each visit were used to calculate variability independent of the mean (VIM) and the coefficient of variation (CV). There were 676 new cases of BD (0.012%). The risk for BD was increased in participants with highly variable and low mean HDL-C levels. In a multivariate-adjusted model, the hazard ratios (95% confidence intervals) for BD incidence were 1.335 (1.058–1.684) in a high mean/high VIM group, 1.527 (1.211–1.925) in a low mean/low VIM group, and 2.096 (1.67–2.63) in a low mean/high VIM group compared to a high mean/low VIM group. Low mean HDL-C levels, and high variability therein, are independent risk factors for BD.

Higher Levels of Serum Uric Acid Have a Significant Association with Lower Incidence of Lower Urinary Tract Symptoms in Healthy Korean Men

Gout has been correlated with the risk of incident benign prostatic hyperplasia. In line with increasing prevalence of hyperuricemia, the aim of this study was to investigate the relationship between serum uric acid (SUA) level and the incidence of lower urinary tract symptoms (LUTS) among clinically healthy middle-aged men. We performed a cohort study in 101,091 Korean men without LUTS at baseline who completed health checkups between 2011 and 2016. LUTS were evaluated using the International Prostate Symptom Score, where a score ≥ 8 was defined as significant LUTS. Men were divided into six groups according to their SUA levels in mg/dL (<5.5, 5.5−6.4, 6.5−7.4, 7.5−8.4, 8.5−9.4, and ≥9.5). Throughout the follow-up—encompassing a total of 358,982.6 person years—13,424 people had significant LUTS (37.3 per 1000 person years for incidence rate). The multivariable models demonstrated that the highest level of SUA (≥9.5 mg/dL) was related to the lowest risk of significant LUTS compared with the reference category (<5.5 mg/dL) (0.77 (95% CI 0.59−0.99) for adjusted HR). In this large cohort composed of middle-aged men, higher SUA levels were related to a reduced risk of LUTS. This result suggests another potential role of SUA in restraining LUTS. Additional studies are needed to explain the underlying biological mechanisms of this phenomenological relationship.

Risk Factors of Incident Lung Cancer in Patients with Non-Cystic Fibrosis Bronchiectasis: A Korean Population-Based Study

BACKGROUND

Patients with non-cystic fibrosis bronchiectasis have an increased risk of lung cancer, followed by higher mortality in this population. Because the risk factors of lung cancer have not been well identified, this study aimed to investigate the risk factors of lung cancer in individuals with newly diagnosed bronchiectasis.

METHODS

This cohort study using the Korean National Health Insurance Service database identified 7425 individuals with incident bronchiectasis among those who participated in the health screening exam in 2009. The cohort was followed from baseline to the date of incident: lung cancer, death, or until the end of the study period. We investigated the risk factors of lung cancer in participants with bronchiectasis using the Cox-proportional hazard models.

RESULTS

During median 8.3 years of follow-up duration, 1.9% (138/7425) developed lung cancer. In multivariable analyses, significant factors associated with increased risk of incident lung cancer included: males (adjusted hazard ratio [HR] = 3.54, 95% confidence interval [CI] = 2.17-5.79) than females, the overweight (adjusted HR = 1.55, 95% CI = 1.03-2.35) than the normal weight, current smokers (adjusted HR = 3.10, 95% CI = 2.00-4.79) than never smokers, participants living in the rural area (adjusted HR = 2.54, 95% CI = 1.68-3.85) than those living in the metropolitan area. Among comorbidities, chronic obstructive pulmonary disease was associated with an increased risk of lung cancer (adjusted HR = 1.46, 95% CI = 1.01-2.13) in participants with bronchiectasis. In contrast, mild alcohol consumption was associated with reduced risk of lung cancer (adjusted HR = 0.47, 95% CI = 0.29-0.74) in those with bronchiectasis.

CONCLUSION

This Korean population-based study showed that males, current smoking, overweight, living in rural areas, and comorbid chronic obstructive pulmonary disease are associated with increased risk of lung cancer in individuals with bronchiectasis.

The Importance of Metabolic Syndrome Status for the Risk of Non-Viral Hepatocellular Carcinoma: A Nationwide Population-Based Study

The positive association between metabolic syndrome (MetS) and hepatocellular carcinoma (HCC) has been suggested. However, no studies have yet looked at how the risk of developing HCC varies with changes in MetS status. Therefore, we aimed to investigate the association between changes in MetS and subsequent HCC development. Data were obtained from the Korean National Health Insurance Service. In this study, 5,975,308 individuals who participated in health screenings both in 2009-2010 and 2011-2012 were included. Individuals with preexisting viral hepatitis, liver cirrhosis, or cancer diagnoses were excluded. Subjects were divided into four groups according to change in MetS status during the 2-year interval screening (from 2009 to 2011): sustained non-MetS, transition to MetS, transition to non-MetS, and sustained MetS. Cox regression analysis was used to examine the hazard ratios of HCC. The subjects were followed through December 31, 2018. During a median of 7.3 years of follow-up, 25,880 incident HCCs were identified. Compared to the sustained non-MetS group, age, sex, smoking, alcohol, regular exercise, and body mass index-adjusted hazard ratios (95% confidence interval) for HCC development were 1.01 (0.97-1.05) for the transition to MetS group, 1.05 (1.003-1.09) for the transition to non-MetS group, and 1.07 (1.03-1.10) for the sustained MetS group. Stratified analyses according to age, sex, smoking, alcohol intake, exercise, diabetes mellitus, hypertension, dyslipidemia, and chronic kidney disease showed similar results. A significantly increased HCC risk was observed in the sustained MetS and transition to non-MetS groups. The baseline status of MetS was associated with the risk of HCC development. Strategies to improve MetS, especially targeting insulin resistance, might prevent HCC development.

Non-Cystic Fibrosis Bronchiectasis Increases the Risk of Lung Cancer Independent of Smoking Status

Rationale

It remains unclear whether non-cystic fibrosis bronchiectasis increases the risk of lung cancer, because smoking history was not considered in previous studies.

Objectives

To evaluate whether participants with bronchiectasis have a higher risk of incident lung cancer than those without bronchiectasis with information on smoking status.

Methods

This was a population-based cohort study of 3,858,422 individuals who participated in the 2009 National Health Screening Program. We evaluated the incidence of lung cancer in participants with bronchiectasis (n = 65,305) and those without bronchiectasis (n = 3,793,117). We followed the cohort up until the date of lung cancer diagnosis, date of death, or December 2018. Cox proportional hazard regression models were used to evaluate the relative risk of lung cancer between participants with bronchiectasis and those without bronchiectasis.

Results

The incidence of lung cancer in participants with bronchiectasis was significantly higher than in those without bronchiectasis (2.1 vs. 0.7 per 1,000 person-years; P < 0.001), with an adjusted hazard ratio (aHR) of 1.22 (95% confidence interval [CI], 1.14–1.30) in the model adjusting for potential confounders and accounting for the competing risk of mortality. Regardless of smoking status, the risk of lung cancer was significantly higher in participants with bronchiectasis than in those without bronchiectasis (aHR, 1.28 [95% CI, 1.17–1.41] for never-smokers; aHR, 1.26 [95% CI, 1.10–1.44] for ever-smokers). Although bronchiectasis did not increase the risk of lung cancer among participants with chronic obstructive pulmonary disease (COPD), it significantly increased the risk of lung cancer in participants without COPD (aHR, 1.19 [95% CI, 1.09–1.31]).

Conclusions

The presence of bronchiectasis was associated with a higher risk of lung cancer after considering the smoking status.

Association between Smoking Status and Incident Non-Cystic Fibrosis Bronchiectasis in Young Adults: A Nationwide Population-Based Study

Smoking traditionally has not been considered as a cause of bronchiectasis. However, few studies have evaluated the association between smoking and bronchiectasis. This study aimed to investigate the association between smoking status and bronchiectasis development in young adults. This study included 6,861,282 adults aged 20−39 years from the Korean National Health Insurance Service database 2009−2012 who were followed-up until the date of development of bronchiectasis, death, or 31 December 2018. We evaluated the incidence of bronchiectasis according to smoking status. During a mean of 7.4 years of follow-up, 23,609 (0.3%) participants developed bronchiectasis. In multivariable Cox regression analysis, ex-smokers (adjusted hazard ratio (aHR) = 1.07, 95% confidence interval (CI) = 1.03−1.13) and current-smokers (aHR = 1.06, 95% CI = 1.02−1.10) were associated with incident bronchiectasis, with the highest HR in ≥ 10 pack-years current smokers (aHR = 1.12, 95% CI = 1.06−1.16). The association of smoking with bronchiectasis was more profound in females than in males (p for interaction < 0.001), in younger than in older participants (p for interaction = 0.036), and in the overweight and obese than in the normal weight or underweight (p for interaction = 0.023). In conclusion, our study shows that smoking is associated with incident bronchiectasis in young adults. The association of smoking with bronchiectasis development was stronger in females, 20−29 year-olds, and the overweight and obese than in males, 30−40-year-olds, and the normal weight or underweight, respectively.

Modest alcohol intake and mortality in individuals with elevated alanine aminotransferase levels: a nationwide cohort study

BACKGROUND

Alanine aminotransferase (ALT) levels are widely used to screen liver disease, and many asymptomatic individuals show elevated ALT levels. As elevated ALT level indicates liver injury, even a small amount of alcohol intake may be harmful in subjects with elevated ALT levels, but there is limited evidence of the effect of light to moderate amount of alcohol intake in this subgroup.

METHODS

A cohort of 367,612 men and women without established liver diseases (including chronic viral hepatitis, alcohol-associated liver disease, cirrhosis, liver transplantation, or rare forms of liver disease) who underwent at least 1 health screening exam between 2009 and 2015 were assessed for liver-related and all-cause mortality. Elevated ALT levels were defined as ≥ 34 U/L for men and 25 U/L for women.

RESULTS

In participants with normal ALT levels, the fully-adjusted hazard ratios (95% CI) for liver-related mortality comparing light and moderate drinkers to non-drinkers were 0.73 (0.51-1.05), and 1.06 (0.73-1.52), respectively. In participants with elevated ALT levels, the corresponding hazard ratios were 1.57 (1.08-2.28), and 2.09 (CI 1.46-2.99), respectively (p value for alcohol intake by ALT interaction < 0.01). For all-cause mortality, the fully-adjusted hazard ratios comparing light and moderate drinkers to non-drinkers in participants with normal ALT levels were 0.72 (0.66-0.77), and 0.89 (0.82-0.97), respectively. In participants with elevated ALT levels, the corresponding hazard ratios were 0.93 (0.81-1.08), and 1.31 (1.14-1.50), respectively (p value for alcohol intake by ALT interaction < 0.01).

CONCLUSIONS

Small amounts of alcohol intake were associated with increased liver-related and all-cause mortality among individuals with elevated ALT levels. Subjects with elevated ALT levels should be advised complete abstinence from alcohol.

Age- and Sex-Specific Differences in Distribution of Cardiometabolic Diseases and Associations of Hand-Grip Strength Indices with Type 2 Diabetes in Korean Adults

Background: To evaluate age- and sex-specific differences in the distribution of cardiometabolic diseases and associations of hand-grip strength (HGS) indices with type 2 diabetes (T2D). Methods: This cross-sectional observational study enrolled participants from the Korea National Health and Nutrition Examination Survey (n = 16,126, age ≥19 years). Information on cardiometabolic diseases was obtained through surveys or proper criteria applied for undiagnosed participants. Absolute and body size-adjusted HGS indices were evaluated. Clinical manifestations were compared, and associations of HGS indices with T2D were estimated by using odd ratio (OR). Results: Prevalence of T2D in all, younger, and older groups were 13.1%, 4.2%, and 21.4%, respectively. Proportions of cardiometabolic diseases were all higher in those with than without T2D in sex-stratified age groups, whereas obesity (OB) and nonalcoholic fatty liver disease (NAFLD) were higher in younger T2D, and hypertension (HTN) was higher in older T2D in both sexes. Adjusted HGS significantly correlated with cardiometabolic parameters, and thus, high ORs for T2D in low tertiles of adjusted HGS were shown in all groups, whereas high ORs for T2D in low tertiles of absolute HGS were observed only in older men. Conclusions: Among highly prevalent cardiometabolic diseases associated with T2D, OB and NAFLD were more prevalent in younger T2D, but HTN was more prevalent in older T2D in both sexes. Low adjusted HGS was associated with higher T2D risk in all groups, whereas low absolute HGS was associated with higher T2D risk in older men. Thus, adjusted HGS might be useful in screening especially younger or obese T2D.

Risk of Osteoporotic Fractures Among Obese Women Based on Body Mass Index and Waist Circumference: A Nationwide Cohort in South Korea

We evaluated the association between obesity status by body mass index (BMI) or waist circumference (WC) and osteoporotic fracture risk. We collected data of 143,673 women with a mean age of 58.5 years without history of osteoporotic fracture from the Korean National Health Insurance Service Cohort. Participants were divided into four groups according to obesity by BMI and WC, normal BMI/WC (BMI 18.5–24.9 kg/m² and WC < 85 cm, reference), obese BMI/normal WC (BMI ≥ 25 kg/m² and WC < 85 cm), normal BMI/obese WC (BMI < 25 kg/m² and WC ≥ 85 cm), and obese BMI/WC (BMI ≥ 25 kg/m² and WC < 85cm). Cox proportional hazards regression analyses were performed to obtain hazard ratios (HRs) with 95% confidence intervals (CIs) for the subsequent median 6.0 years, which were adjusted for age, socioeconomic status, lifestyle, morbidity index, and osteoporosis medication. Compared with the normal group, normal BMI/obese WC was associated with a higher osteoporotic fracture risk after multivariable adjustment (HRs [95% CI], 1.13 [1.05–1.21]), and obese BMI/normal WC was associated with a lower osteoporotic fracture risk (0.89 [0.84–0.94]). Obese BMI/normal WC was associated with a lower risk for hip fractures (0.75 [0.57–0.99]). Obese BMI/normal WC was associated with decreased risk of osteoporotic fracture, whereas normal BMI/obese WC was associated with increased risk of osteoporotic fracture compared with the normal group among East Asian women in their late 40s or more.

Microcalcifications, mammographic breast density, and risk of breast cancer: a cohort study

BACKGROUND

Breast density and microcalcifications are strongly associated with the risk of breast cancer. However, few studies have evaluated the combined association between these two factors and breast cancer risk. We investigated the association between breast density, microcalcifications, and risk of breast cancer.

METHODS

This cohort study included 3,910,815 women aged 40-74 years who were screened for breast cancer between 2009 and 2010 and followed up until 2020. The National Health Insurance Service database includes national health-screening results from the national breast cancer screening program, which is an organized screening program provided every 2 years for all women aged 40 years or older. Breast density was assessed based on the Breast Imaging Reporting and Data System (BI-RADS) 4^th edition, mostly through visual assessment by radiologists. The presence or absence of microcalcifications was obtained from the mammographic results. Cox proportional hazard regression for breast cancer risk was used to estimate hazard ratios (aHRs) adjusted for breast cancer risk factors.

RESULTS

A total of 58,315 women developed breast cancer during a median follow-up of 10.8 years. Women with breast cancer had a higher proportion of microcalcifications than women without breast cancer (0.9% vs. 0.3%). After adjusting for breast density, women with microcalcification had a 3.07-fold (95% confidence interval [CI] 2.82-3.35) increased risk of breast cancer compared to women without microcalcification. The combined association between microcalcification and breast density dramatically increased the risk of breast cancer, corresponding to a higher level of breast density. Among postmenopausal women, the highest risk group was women with BI-RADS 4 and microcalcification. These women had more than a sevenfold higher risk than women with BI-RADS 1 and non-microcalcification (aHR, 7.26; 95% CI 5.01-10.53).

CONCLUSION

Microcalcification is an independent risk factor for breast cancer, and its risk is elevated when combined with breast density.

The Change in Metabolic Syndrome Status and the Risk of Nonviral Liver Cirrhosis

Background: Nonalcoholic fatty liver disease is considered to be the hepatic component of metabolic syndrome (MetS). However, the association between changes in MetS status and the risk of liver cirrhosis (LC) has not been investigated to date. This study assessed the association between changes in MetS and subsequent nonviral LC development. Methods: Data were obtained from the Korean National Health Insurance Service. Individuals who participated in health screenings from both 2009 to 2010 and 2011 to 2012 were included. The primary outcome was LC development according to the static and dynamic MetS status. Subjects were stratified into four groups according to the change in MetS status observed from the two-year interval screening (2009–2011). Cox regression analysis was used to examine the hazard ratios of LC. Results: During a median of 7.3 years of follow-up, 24,923 incident LC cases developed among 5,975,308 individuals. After adjusting for age, sex, smoking, alcohol, regular exercise, and body mass index, the adjusted hazard ratios (95% confidence intervals) for LC development were 1.39 (1.33–1.44) for the MetS-Developed group, 1.32 (1.26–1.37) for the MetS-Recovered group, and 1.51 (1.45–1.56) for the MetS-Sustained group, relative to the MetS-Free group. Stratified analyses according to age, sex, smoking, alcohol intake, exercise, diabetes mellitus, hypertension, dyslipidemia, and chronic kidney disease showed similar results. Conclusions: Both static and dynamic MetS status are independent risk factors for LC development. The risk of LC was the highest in people with sustained MetS and was lower in the MetS-Recovered group than in the MetS-Sustained group. These results suggest that improving a person’s MetS status may be helpful in preventing LC.

Comparison of fracture risk between type 1 and type 2 diabetes: a comprehensive real-world data

Population-based cohort study of 6,548,784 Korean subjects demonstrates that the risk of fracture was higher in patients with diabetes than in nondiabetic subjects. Furthermore, patients with type 1 diabetes were associated with a higher risk of fracture than patients with type 2 diabetes for all measurement sites.

INTRODUCTION

Diabetes mellitus is associated with increased fracture risk. Although the pathophysiologic effect on bone metabolism differs according to the type of diabetes, a higher risk of fracture in patients with diabetes than in nondiabetic patients has been consistently demonstrated. Considering the ever-increasing number of patients with diabetes, we aimed to provide updated information on whether this phenomenon remains valid in real-world settings by using large-scale population datasets.

METHODS

We conducted a retrospective longitudinal study using data from the Korean National Health Insurance Service dataset of preventive health check-ups between January 2009 and December 2016. The hazard ratios were calculated for any fracture, vertebral fracture, and hip fracture and were analyzed according to the presence and type of diabetes. Among 10,585,818 subjects, 6,548,784 were eligible for the analysis (2418 patients with type 1 diabetes mellitus [T1DM] and 506,208 patients with type 2 diabetes mellitus [T2DM]).

RESULTS

The mean follow-up duration (in years) was 7.0 ± 1.3 for subjects without diabetes, 6.4 ± 2.0 for those with T1DM, and 6.7 ± 1.7 for T2DM. Patients with T1DM had a higher incidence rate for all types of fractures per 1000 person-years. The fully adjusted hazard ratios (HRs) for any fracture, vertebral fracture, and hip fracture were higher in T1DM than in T2DM (1.37 [95% confidence interval (CI): 1.23-1.52] for any fracture, 1.33 [95% CI: 1.09-1.63] for vertebral fracture, and 1.99 [95% CI: 1.56-2.53] for hip fracture).

CONCLUSIONS

In this large-scale population analysis, diabetes was associated with a higher risk of all types of fractures. Patients with T1DM had a higher risk of fracture than those with T2DM for all measurement sites, and hip fractures had the highest risk. Therefore, fracture prevention training for patients with diabetes is advisable.

Weight change and resolution of fatty liver in normal weight individuals with nonalcoholic fatty liver disease

OBJECTIVES

Obesity is a well-known risk factor for nonalcoholic fatty liver disease (NAFLD), and weight reduction is primarily recommended for managing the disease. However, some NAFLD patients have a normal weight (lean NAFLD), and whether weight reduction is also recommendable for lean NAFLD patients remains unclear.

METHODS

We conducted a longitudinal study of 16 738 adults (average age, 50.5 years; lean NAFLD, 2383 participants) with NAFLD at baseline who underwent repeated health check-up examinations, including bodyweight measurements and abdominal ultrasonography from January 2003 through December 2013.

RESULTS

During 68 389 person-years of follow-up (median follow-up of 3.00 years), 5819 patients had a fatty liver resolution. Compared with participants who had no weight reduction or increased weight, the fully adjusted hazard ratios for fatty liver resolution in participants with 0-4.9, 5-9.9 and 10% or more weight reduction were 1.67 [95% confidence interval (CI), 1.57-1.77], 3.36 (95% CI, 3.09-3.65) and 5.50 (95% CI, 4.83-6.27), respectively. The association between weight reduction and the fatty liver resolution was stronger in overweight/obese NAFLD participants but was also evident in lean NAFLD participants in a dose-dependent manner. In spline regression models, the association between weight change and the fatty liver resolution was linear among participants with normal weight.

CONCLUSION

There was a dose-dependent association between weight reduction and fatty liver resolution in both lean and overweight/obese NAFLD patients. This finding suggests weight reduction as a primary recommendation for lean NAFLD patients as in overweight/obese NAFLD patients.

Association between metabolic syndrome and incidence of ocular motor nerve palsy

To assess the association between metabolic syndrome (MetS) and the development of third, fourth, and sixth cranial nerve palsy (CNP). Health checkup data of 4,067,842 individuals aged between 20 and 90 years provided by the National Health Insurance Service (NHIS) of South Korea between January 1, 2009, and December 31, 2009, were analyzed. Participants were followed up to December 31, 2017. Hazard ratio (HR) and 95% confidence interval (CI) of CNP were estimated using Cox proportional hazards regression analysis after adjusting for potential confounders. Model 1 included only incident CNP as a time-varying covariate. Model 2 included model 1 and individual’s age and sex. Model 3 included model 2, smoking status, alcohol consumption, and physical activity of individuals. We identified 5,835 incident CNP cases during the follow-up period (8.22 ± 0.94 years). Individuals with MetS (n = 851,004) showed an increased risk of CNP compared to individuals without MetS (n = 3,216,838) after adjustment (model 3: HR = 1.35, 95% CI 1.273–1.434). CNP incidence was positively correlated with the number of MetS components (log-rank p < 0.0001). The HR of CNP for males with MetS compared to males without MetS was higher than that of females with MetS compared to females without MetS (HR: 1.407, 95% CI 1.31–1.51 in men and HR: 1.259, 95% CI 1.13–1.40 in women, p for interaction = 0.0017). Our population-based large-scale cohort study suggests that MetS and its components might be risk factors for CNP development.

Fatty Liver Index for Predicting Nonalcoholic Fatty Liver Disease in an Asymptomatic Korean Population

Nonalcoholic fatty liver disease (NAFLD) is increasing worldwide, highlighting the importance of early and accurate detection and the appropriate management of NAFLD. However, ultrasonography (US) is not included in many mass screening programs, and people have limited access to it. The aim of this study is to validate the fatty liver index (FLI) and investigate the optimal cutoff value for predicting NAFLD in an asymptomatic population. We conducted a retrospective cohort study in Korea. All subjects who underwent health checkup exams, including abdominal US, controlled attenuation parameter (CAP) and blood testing, were enrolled. Analyses of the area under the receiver operating characteristic curve (AUROC) were used to evaluate the diagnostic accuracy and to calculate the optimal FLI cutoff for US-NAFLD. Among the 4009 subjects (mean age 54.9 years, 83.5% male), the prevalence of US-diagnosed NAFLD and CAP-defined hepatic steatosis was 61.4% and 55.4%. The previously used cutoff of FLI = 60 showed poor performance in predicting US-diagnosed NAFLD, with an AUROC of 0.63 (0.62–0.64), and CAP-defined NAFLD, with an AUROC 0.63 (0.62–0.64). The optimal FLI cutoff values to discriminate fatty liver detected by US were 29 for the entire population, with an AUROC of 0.82 (0.81–0.84). The sex-specific values were 31 for males and 18 for females (sensitivity 72.8% and 73.4%; specificity 74.2% and 85.0%, respectively). The FLI cutoff for US-diagnosed NAFLD can be set as 29 for the entire Korean population. Considering the sex dimorphism in NAFLD, different cutoff values are suggested to predict US-diagnosed NAFLD. These results may be helpful in the accurate non-invasive diagnosis of NAFLD.