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Background: This study aimed to examine the association between coffee or green tea consumption and ferritin or hemoglobin levels in premenopausal women.Methods: We used the fifth Korea National Health and Nutrition Examination Survey (2010–2012), and a total of 4,322 individuals were surveyed. In women of reproductive age, average ferritin and hemoglobin levels were calculated according to coffee or green tea consumption. Covariates included in the analysis were demographic variables, such as age, body mass index, education, drinking, smoking, history of hypertension, history of diabetes diagnosis, physical activity, total energy intake, and daily iron intake.Results: In 4,322 participants, the average hemoglobin level was 12.90±0.02 g/dL, and the average level of ferritin was 31.95±0.67 ng/mL. As a result of testing, correlation between ferritin and coffee intake and difference in ferritin levels according to coffee consumption was significant (P2 cups of coffee significantly affect ferritin levels in Korean premenopausal women.

High photoluminescent InP/ZnS QDs synthesis by in situ H2S interface engineering.

Background Little is known about the risk of ischemic heart disease (IHD) in tuberculosis (TB) survivors. Methods We performed a population-based retrospective cohort study using the Korean National Health Insurance Service database. TB survivors (n = 60 602) and their 1:1 age- and sex-matched controls (n = 60 602) were enrolled. Eligible participants were followed up from 1 year after their TB diagnosis to the date of an IHD event, date of death, or the end of the study period (31 December 2018), whichever came first. The risk of IHD was estimated using a Cox proportional hazards regression, and stratified analyses were performed for related factors. Among IHD events, we additionally analyzed for myocardial infarction (MI). Results During a median of 3.9 years of follow-up, 2.7% of TB survivors (1633/60 602) and 2.0% of the matched controls (1228/60 602) developed IHD, and 0.6% of TB patients (341/60 602) and 0.4% of the matched controls (223/60 602) developed MI. The overall risk of developing IHD and MI was higher in TB patients (adjusted hazard ratio [aHR] 1.21, 95% confidence interval [CI]: 1.12–1.32 for IHD and aHR 1.48, 95% CI: 1.23–1.78 for MI) than in the matched controls. Stratified analyses showed that TB survivors have an increased risk of IHD and MI regardless of income, place of residence, smoking status, alcohol consumption, physical activity, body mass index, and Charlson comorbidity index. Conclusions TB survivors have a higher risk of IHD than matched controls. Strategies are needed to reduce the burden of IHD in TB survivors.

Background Although the morbidity and mortality of cardiovascular diseases (CVD) are rising in young women, the risk factors of CVD among Korean pre-menopausal women have not been intensively investigated. Aims To determine how age at menarche and other female reproductive factors are associated with the risk of CVD in pre-menopausal women. Methods and results A total of 1 088 992 pre-menopausal women who participated in health screening in 2009 were included. The study outcomes were myocardial infarction (MI) and ischaemic stroke. Cox proportional hazards regression analysis was conducted with adjustment of traditional CVD risk factors and reproductive factors. Results Mean age was 43.8 ± 5.3 years (98.9%, < 55 years), 3.5% were current smokers, and 1.2% were heavy drinkers. During a mean follow-up of 8.3years [9 032 685.9 person-years (PY)], there were 10 876 CVD events (1.0 per 1000 PY).With later menarche, the risk of CVD increased; ≤12 years [adjusted hazard ratio (HR) 1.04, 95% confidence interval 0.93–1.16], 13 years (reference), 14 years (1.06, 0.98–1.14), 15 years (1.15, 1.07–1.24), 16 years (1.23, 1.14–1.34), and ≥17 years (1.33, 1.24–1.44). Compared with non-users, oral contraceptives (OC) users (≥1 year) had an increased risk of CVD (1.11, 1.01–1.22) (P for trend = 0.007). Conclusions Later menarche than the mean age at menarche (13 years old) and the use of OC (≥1 year) were associated with a higher risk of CVD, after adjusting for traditional cardiovascular risk factors. This study suggests that female reproductive factors could be unique risk factors for CVD in pre-menopausal women.

To examine the association between comorbid mental disorders and cardiovascular disease (CVD) risk among patients with type 2 diabetes.This retrospective cohort study was conducted using the claims data of 2,227,394 South Korean patients with type 2 diabetes. We analyzed the occurrence of CVD including myocardial infarction (MI) and ischemic stroke, CVD-specific mortality, and all-cause mortality according to comorbid mental disorders including depressive disorders, bipolar and related disorders, schizophrenia spectrum disorders, insomnia, and anxiety disorders.Among the patients, 9.1% had a comorbid mental disorder. The adjusted hazard ratios (aHR) for MI, ischemic stroke, CVD-specific mortality, and all-cause mortality in patients with any mental disorder were 1.20 (95% CI, 1.17-1.24), 1.13 (95% CI, 1.11-1.16), 1.16 (95% CI, 1.12-1.20), and 1.21 (95% CI, 1.19-1.23), respectively. Each mental disorder increased the risk of all outcomes, particularly bipolar and related disorders and schizophrenia spectrum disorders.Comorbid mental disorders increased the CVD risk in patients with type 2 diabetes, with significantly increased risks associated with schizophrenia spectrum disorders (aHR: 1.27 for MI and 1.50 for ischemic stroke) and bipolar and related disorders (aHR: 1.27 for MI and 1.45 for ischemic stroke).

Hair loss is a common status found among people of all ages. Since the role of hair is much more related to culture and individual identity, hair loss can have a great influence on well-being and quality of life. It is a disorder that is observed in only scalp patients with androgenetic alopecia (AGA) or alopecia areata caused by stress or immune response abnormalities. Food and Drug Administration (FDA)-approved therapeutic medicines such as finasteride, and minoxidil improve hair loss temporarily, but when they stop, they have a limitation in that hair loss occurs again. As an alternative strategy for improving hair growth, many studies reported that there is a relationship between the expression levels of prostaglandins (PGs) and hair growth. Four major PGs such as prostaglandin D2 (PGD

Background: Metabolic syndrome (MetS) is believed to increase the risk of esophageal cancer. However, most studies have been conducted in Western countries, focusing on esophageal adenocarcinoma (EAC). We aimed to investigate the association between MetS and risk of esophageal cancer in nationally representative large dataset in Korea, where esophageal squamous cell carcinoma (ESCC) is predominant. Methods: We analyzed the health examinations and claims data from the Korean National Health Insurance Service (NHIS). A total of 6,795,738 subjects who received an NHIS provided health examination in 2009 (index year) were included. Cox proportional hazards models were used to estimate multivariable adjusted HRs (aHR) and 95% confidence intervals (CI) for the association of MetS and its components (elevated waist circumference, blood pressure, triglycerides, fasting blood glucose, reduced high-density lipoprotein cholesterol) with the risk of esophageal cancer. Results: During a mean (± SD) follow-up of 8.2 (± 1.1) years, 6,414 cases of esophageal cancer occurred. MetS was associated with an increased risk of esophageal cancer (aHR, 1.11; 95% CI, 1.05–1.18). Among the components of MetS, elevated waist circumference (aHR, 1.24; 95% CI, 1.16–1.33), high blood pressure (aHR, 1.29; 95% CI, 1.22–1.37), and fasting blood glucose (aHR, 1.16; 95% CI, 1.11–1.22) were associated with increased risk of esophageal cancer. Conclusions: MetS was associated with an increased risk of esophageal cancer. Impact: Our findings suggest that individuals with MetS may be at increased risk for esophageal cancer, specifically ESCC. Further studies are needed to establish the relationship between MetS and esophageal cancer.

Background: The effect of serial change in alcohol consumption on stroke risk has been limitedly evaluated. We investigated the association of change in alcohol consumption with risk of stroke. Methods: This study is a population-based retrospective cohort study from National Health Insurance Service database of all Koreans. Four lakh five hundred thirteen thousand seven hundred forty-six participants aged ≥40 years who underwent 2 subsequent national health examinations in both 2009 and 2011. Alcohol consumption was assessed by average alcohol intake (g/day) based on self-questionnaires and categorized into non-, mild, moderate, and heavy drinking. Change in alcohol consumption was defined by shift of category from baseline. Cox proportional hazards model was used with adjustment for age, sex, smoking status, regular exercise, socioeconomic information, and comorbidities, Charlson Comorbidity Index, systolic blood pressure, and laboratory results. Subgroup analysis among those with the third examination was conducted to reflect further change in alcohol consumption. Results: During 28 424 497 person-years of follow-up, 74 923 ischemic stroke events were identified. Sustained mild drinking was associated with a decreased risk of ischemic stroke (adjusted hazard ratio, 0.88 [95% CI, 0.86–0.90]) compared with sustained nondrinking, whereas sustained heavy drinking was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.06 [95% CI, 1.02–1.10]). Increasing alcohol consumption was associated with an increased risk of ischemic stroke (adjusted hazard ratio, 1.11 [95% CI, 1.06–1.17] from mild to moderate; adjusted hazard ratio, 1.28 [95% CI, 1.19–1.38] from mild to heavy) compared with sustained mild drinkers. Reduction of alcohol consumption from heavy to mild level was associated with 17% decreased risk of ischemic stroke through 3× of examinations. Conclusions: Light-to-moderate alcohol consumption is associated with a decreased risk of ischemic stroke, although it might be not causal and could be impacted by sick people abstaining from drinking. Reduction of alcohol consumption from heavy drinking is associated with a decreased risk of ischemic stroke.

Background:Metabolic syndrome (MetS) is believed to increase the risk of esophageal cancer. However, most studies have been conducted in Western countries, focusing on esophageal adenocarcinoma (EAC). We aimed to investigate the association between MetS and risk of esophageal cancer in nationally representative large dataset in Korea, where esophageal squamous cell carcinoma (ESCC) is predominant.Methods:We analyzed the health examinations and claims data from the Korean National Health Insurance Service (NHIS). A total of 6,795,738 subjects who received an NHIS provided health examination in 2009 (index year) were included. Cox proportional hazards models were used to estimate multivariable adjusted HRs (aHR) and 95% confidence intervals (CI) for the association of MetS and its components (elevated waist circumference, blood pressure, triglycerides, fasting blood glucose, reduced high-density lipoprotein cholesterol) with the risk of esophageal cancer.Results:During a mean (± SD) follow-up of 8.2 (± 1.1) years, 6,414 cases of esophageal cancer occurred. MetS was associated with an increased risk of esophageal cancer (aHR, 1.11; 95% CI, 1.05–1.18). Among the components of MetS, elevated waist circumference (aHR, 1.24; 95% CI, 1.16–1.33), high blood pressure (aHR, 1.29; 95% CI, 1.22–1.37), and fasting blood glucose (aHR, 1.16; 95% CI, 1.11–1.22) were associated with increased risk of esophageal cancer.Conclusions:MetS was associated with an increased risk of esophageal cancer.Impact:Our findings suggest that individuals with MetS may be at increased risk for esophageal cancer, specifically ESCC. Further studies are needed to establish the relationship between MetS and esophageal cancer.

Previous studies on the association between metabolic syndrome and risk of esophageal cancer

Baseline characteristics of the non-smoker/ non-drinker group

Background and purposeThe 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.MethodsData 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.ResultsAmong 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 FLIversus 1.06 and 1.05–1.08, respectively).ConclusionsA 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.

Background Age‐related macular degeneration (AMD) is the leading cause of visual disability. AMD shares some risk factors with the pathogenesis of cardiovascular disease (CVD). However, previous studies examining the association between AMD and the risk of CVD provide conflicting results. Hence, we investigated the association between AMD, visual disability, and the risk of CVD. Methods and Results This is a nationwide cohort study using data from the Korean National Health Insurance System database (2009–2019) on subjects who underwent a national health screening program in 2009. A total of 3 789 963 subjects were categorized by the presence of AMD and visual disability. Visual disability was defined as a best‐corrected visual acuity of ≤20/100 by validated documentation from a specialist physician. Cox regression hazard model was used to examine the hazard ratios (HRs) of CVD, including myocardial infarction and ischemic stroke, after adjusting for potential confounders. During a mean 9.77 years of follow‐up, AMD was associated with a 5% higher risk of myocardial infarction (adjusted HR [aHR], 1.05 [95% CI, 1.01–1.10]) but not associated with increased risk of overall CVD (aHR, 1.02 [95% CI, 1.00–1.05]) or ischemic stroke (aHR, 1.02 [95% CI, 0.98–1.06]). However, when AMD was accompanied by visual disability, there was increased risk of CVD (aHR, 1.17 [95% CI, 1.06–1.29]), myocardial infarction (aHR, 1.18 [95% CI, 1.01–1.37]), and ischemic stroke (aHR, 1.20 [95% CI, 1.06–1.35]). These trends were more evident in women and subjects with cardiometabolic comorbidities. Conclusions AMD with visual disability, but not all AMD, was associated with an increased risk of CVD. Patients with AMD who have visual disability should be targeted for CVD prevention.

ImportanceAlthough it has been postulated that chronic inflammation caused by rheumatoid arthritis (RA) contributes to the development of Parkinson disease (PD), the association between these 2 conditions has yet to be determined.ObjectiveTo evaluate the association between RA and subsequent PD risk.Design, Setting, and ParticipantsThis retrospective cohort study used the Korean National Health Insurance Service database to collect population-based, nationally representative data on patients with RA enrolled from 2010 to 2017 and followed up until 2019 (median follow-up, 4.3 [IQR, 2.6-6.4] years after a 1-year lag). A total of 119 788 patients who were first diagnosed with RA (83 064 with seropositive RA [SPRA], 36 724 with seronegative RA [SNRA]) were identified during the study period and included those who underwent a national health checkup within 2 years before the RA diagnosis date (64 457 patients). After applying exclusion criteria (eg, age ExposuresRheumatoid arthritis as defined using International Classification of Diseases, Tenth Revision codes M05 for SPRA and M06 (except M06.1 and M06.4) for SNRA; prescription of any disease-modifying antirheumatic drug; and enrollment in the Korean Rare and Intractable Diseases program.Main Outcomes and MeasuresThe main outcome was newly diagnosed PD. Data were analyzed from May 10 through August 1, 2022, using Cox proportional hazards regression analyses.ResultsFrom the 328 080 individuals analyzed (mean [SD] age, 58.6 [10.1] years; 74.9% female and 25.1% male), 1093 developed PD (803 controls and 290 with RA). Participants with RA had a 1.74-fold higher risk of PD vs controls (95% CI, 1.52-1.99). An increased risk of PD was found in patients with SPRA (adjusted hazard ratio [aHR], 1.95; 95% CI, 1.68-2.26) but not in patients with SNRA (aHR, 1.20; 95% CI, 0.91-1.57). Compared with the SNRA group, those with SPRA had a higher risk of PD (aHR, 1.61; 95% CI, 1.20-2.16). There was no significant interaction between covariates on risk of PD.Conclusions and RelevanceIn this study, RA was associated with an increased risk of PD, and seropositivity of RA conferred an augmented risk of PD. The findings suggest that physicians should be aware of the elevated risk of PD in patients with RA and promptly refer patients to a neurologist at onset of early motor symptoms of PD without synovitis.

PurposeWhile renal impairment is one of the first clinical manifestations of multiple myeloma (MM), declined renal function may conversely be a risk factor for cancers including MM. In this study, we investigated the relationship between chronic kidney disease and MM at a population level. Materials and MethodsA total of 9,809,376 adults who participated in a nationwide health screening program and had no MM, cancer or end-stage renal disease at baseline were investigated for incidence of MM. The impact of estimated glomerular filtration rate (eGFR) and random urine dipstick proteinuria, and interactive associations of the two factors on the MM incidence were evaluated. ResultsThe general incidence of MM was 4.8 per 100,000 person-years (mean follow-up of 8.3 years). Participants with eGFR < 60 mL/min/1.73 m2 (5.8% of participants) had higher MM incidence than those with eGFR ≥ 60 mL/min/1.73 m2 (adjusted hazard ratio, 1.29; 95% confidence interval, 1.17 to 1.43). When eGFR was graded into five levels, there was a significant inverse dose-response relationship between eGFR level and MM incidence at the lower eGFR levels (reference: eGFR 60-89 mL/min/1.73 m2). A dose-response relationship was also found with degree of dipstick proteinuria and incidence of MM.ConclusionAdults with decreased renal function indicated either by decreased eGFR or presence of proteinuria are at a higher risk of developing MM compared to those without, and there is a dose-response relationship between the severity of renal impairment and MM incidence.

Background When assessing long-term tuberculosis (TB) mortality, few studies addressed the impact of behavior habits and socioeconomic status. Therefore, we aimed to evaluate long-term TB mortality and risk factors while accounting for potential confounders. Methods This cohort study included TB survivors (n = 82 098) aged ≥20 years between 2010 and 2017, and 1:1 age- and sex-matched controls (n = 82 098). The participants were followed up for death 1 year after study enrollment until December 2018. Long-term mortality was adjusted for behavior habits (smoking, alcohol consumption, or exercise), income level, body mass index (BMI), and comorbidities. Results During a median of 3.7 years of follow-up, the incidence rate of mortality was significantly higher in TB survivors than those in the matched controls (18.2 vs. 8.8 per 1000 person-years, P < .001). Even after adjusting for potential confounders, the mortality risk was 1.62-fold (95% confidence interval [CI], 1.54–1.70) higher in TB survivors than those in the matched controls. In addition, the hazard of mortality in TB survivors relative to matched controls significantly increased in participants aged ≥30 years, with the highest risk in those in their 40s. Male sex (adjusted hazard ratio [HR]: 2.31; 95% CI, 2.16–2.47), smoking pack-years (HR: 1.005; 95% CI, 1.004–1.006), heavy alcohol consumption (HR: 1.12; 95% CI, 1.01–1.23), and lowest income (HR: 1.27; 95% CI, 1.18–1.37) were positively associated with increased hazards for mortality, whereas higher BMI (HR: 0.91; 95% CI, .90–.92) and regular exercise (HR: 0.82; 95% CI, .76–.88) reduced the hazards of long-term mortality in TB survivors. Conclusions The long-term mortality risk was significantly higher in TB survivors than those in the matched controls, even after adjusting for potential confounders.

Background: Hyperthyroidism is associated with an increased glomerular filtration rate (GFR) in the hyperdynamic state, which is reversible after restoring euthyroidism. However, long-term follow-up of renal dysfunction in patients with hyperthyroidism has not been performed.Methods: This was a retrospective cohort study using the Korean National Health Insurance database and biannual health checkup data. We included 41,778 Graves’ disease (GD) patients and 41,778 healthy controls, matched by age and sex. The incidences of end-stage renal disease (ESRD) were calculated in GD patients and controls. The cumulative dose and duration of antithyroid drugs (ATDs) were calculated for each patient and categorized into the highest, middle, and lowest tertiles.Results: Among 41,778 GD patients, 55 ESRD cases occurred during 268,552 person-years of follow-up. Relative to the controls, regardless of smoking, drinking, or comorbidities, including chronic kidney disease, GD patients had a 47% lower risk of developing ESRD (hazard ratio [HR], 0.53; 95% confidence interval [CI], 0.37 to 0.76). In particular, GD patients with a higher baseline GFR (≥90 mL/min/1.73 m2; HR, 0.33; 95% CI, 0.11 to 0.99), longer treatment duration (>33 months; HR, 0.31; 95% CI, 0.17 to 0.58) or higher cumulative dose (>16,463 mg; HR, 0.29; 95% CI, 0.15 to 0.57) of ATDs had a significantly reduced risk of ESRD.Conclusion: This was the first epidemiological study on the effect of GD on ESRD, and we demonstrated that GD population had a reduced risk for developing ESRD.

The association between smoking, alcohol consumption, and thyroid cancer has been evaluated in observational studies, yet the results remain controversial. In the present investigation, we analyzed a longitudinal cohort study with representative data to determine the association between smoking, alcohol consumption, and thyroid cancer risk, allowing for risk modification due to age and sex.From the Korean National Health Insurance database, .subjects aged ≥20 who participated in health screening program in 2009 were identified and followed-up till 2017. The adjusted hazard ratio (aHR) for the risk of thyroid cancer was estimated by Cox proportional hazard model Results: During a mean follow-up period of 8.33 ± 0.57 years, out of 9,699,104 participants, 89,527 (0.9%) were diagnosed with thyroid cancer. In comparison with those who never smoked, current smokers [aHR: 0.74, 95% confidence interval (CI): 0.72-0.76)] had a decreased risk of thyroid cancer even though ex-smokers (aHR: 0.98, 95% CI: 0.96-1.01) did not. There was no dose-response relationship when the participants were examined with regard to the daily amount of smoking, duration of smoking, and pack-years. A decrease in the risk of thyroid cancer was observed according to both the number of drinking episodes per week and the number of glasses per once drinking (HR: 0.81, 95% CI: 0.74-0.88 for drinks consumed 7 times/week and HR: 0.87, 95% CI: 0.82-0.92 for ≥ 15 glasses once drinking vs. nondrinkers). A certain degree of alcohol consumption seemed to provoke a decreased risk of thyroid cancer as compared to those who did not drink (HR: 0.85, 95% CI: 0.81-0.89 for ≥ 40 g/week). The interaction of smoking and alcohol consumption was found to be significant (p-interaction0.0001), and sub-multiplicative.We found that the risk of thyroid cancer incidence was inversely associated with smoking and alcohol consumption. A sub-multiplicative interaction between smoking and alcohol intake on the risk of thyroid cancer was found. Further studies are needed to elucidate exactly how smoking and alcohol are related to the pathogenesis and the modification their effects may have on thyroid cancer development.

Health screening is an important component of health promotion programs, and countries have promoted general health screening targeting the prevention and early management of common chronic diseases. In Korea, a General Health Screening Program (GHSP) began with workers in the 1950s and continuously expanded its target population, and currently includes the adult population. The main target diseases are cerebroand cardiovascular diseases, including hypertension, diabetes mellitus, dyslipidemia, obesity, and related health behaviors. Other target conditions include other diseases (e.g., anemia, liver disease, visual/auditory impairment), mental health (e.g., depression), and geriatric disease and function (osteoporosis, dementia, risk of fall, etc.). The National Health Information Database, including GHSP information, is now extensively used in clinical and public health research. The participation rate is currently 70% to 80%, but varies according to age, disability, and the socioeconomic status. There is a need for a more systematic evaluation of the screening items, reducing disparity gaps in participation, and linking GHSP to actual health promotion.

The objective of this study was to investigate the effects of reduction, cessation, and resumption of smoking on cancer development.The authors identified 893,582 participants who currently smoked, had undergone a health screening in 2009, and had a follow-up screening in 2011. Among them, 682,996 participated in a third screening in 2013. Participants were categorized as quitters, reducers I (≥50% reduction), reducers II (50% reduction), sustainers (referent), or increasers (≥20% increase). Outcome data were obtained through December 31, 2018.Reducers I exhibited a decreased risk of all cancers (adjusted hazard ratio [aHR], 0.96; 95% confidence interval [CI], 0.93-0.99), smoking-related cancers (aHR, 0.95; 95% CI, 0.92-0.99), and lung cancer (aHR, 0.83; 95% CI, 0.77-0.88). Quitters had the lowest risk of all cancers (aHR, 0.94; 95% CI, 0.92-0.96), smoking-related cancers (aHR, 0.91; 95% CI, 0.89-0.93), and lung cancer (aHR, 0.79; 95% CI, 0.76-0.83). In further analysis with 3 consecutive screenings, additional smoking reduction (from reducers II to reducers I) lowered the risk of lung cancer (aHR, 0.74; 95% CI, 0.58-0.94) in comparison with sustainers. Quitting among reducers I further decreased the risk of all cancers (aHR, 0.90; 95% CI, 0.80-1.00), smoking-related cancers (aHR, 0.81; 95% CI, 0.81-0.92), and lung cancer (aHR, 0.66; 95% CI, 0.52-0.84) in comparison with sustainers. Smoking resumption after quitting, even at a lower level, increased the risk of smoking-related cancers (aHR, 1.19; 95% CI, 1.06-1.33) and lung cancer (aHR, 1.48; 95% CI, 1.21-1.80) in comparison with sustained quitting.Smoking cessation and, to a lesser extent, smoking reduction decreased the risks of cancer. Smoking resumption increased cancer risks in comparison with sustained quitting.Worldwide, tobacco use is the single leading preventable risk factor for cancer and cancer death. This study examined the effects of reduction, cessation, and resumption of smoking on cancer development by measuring smoking behavior repetitively. Although smoking reduction has a substantial cancer prevention benefit for those who cannot quit, cessation should be encouraged whenever possible. Quitters should be monitored to ensure that they do not resume smoking.

Background Body weight variability (BWV) negatively affects the incidence and outcomes of various diseases, but the nature of the association between BWV and depression remains unclear. In this study, we aimed to test the hypothesis that BWV is associated with the risk of new-onset depression. Methods Data from a nationwide population-based cohort in the Korean National Health Insurance Service database were analyzed for 6 598 570 adults with no history of depression and reports of at least three health examinations. BWV was estimated using variability independent of the mean indices and divided into quartiles (Q1 lowest, Q4 highest BWV). Cox proportional hazard models were applied to assess the risk of depression according to the quartile of BWV. Results The incident rate for depression from Q1 to Q4 of BWV was 20.7, 20.3, 20.8, and 22.2 per 1000 person-years, respectively. BWV, especially high BWV, was associated with an increased risk of depression after adjusting for age, sex, smoking, alcohol consumption, physical activity, income, diabetes mellitus, hypertension, and dyslipidemia. The hazard ratio (HR) of new-onset depression was highest in Q4 relative to Q1 in the total population (HR 1.12, p < 0.0001) and was higher in women than in men (HR 1.72 v. 1.16, p < 0.0001). In stratified analyses, regardless of obesity or weight change status at baseline, the risk of depression was increased when bodyweight fluctuated highly during follow-up. Conclusions High BWV was associated with an increased risk of depression. Further studies need to evaluate the role of high BWV with respect to the onset of depression.

PURPOSE To evaluate the association between high-density lipoprotein (HDL) cholesterol levels and the future risk of retinal artery occlusion (RAO). DESIGN Population-based cohort study. METHODS This study used data provided by the Korean National Health Insurance Service. A total of 9,316,212 individuals over 40 years of age who participated in the Korean National Health Screening Program in 2013 or 2014 were included. Data on risk factors, including age, sex, income level, systemic comorbidities, behavioral factors, and baseline lipid profiles, were collected from health screening results and claims data. Patients were followed up until December 2018, and incident cases of RAO were identified using registered diagnostic codes from claims data. A prospective association between HDL cholesterol level and incident RAO was investigated using the multivariable-adjusted Cox proportional hazard model. RESULTS During an average follow-up period of 4.93 years, 9,878 patients were newly diagnosed with RAO. Compared to those with low HDL cholesterol levels (< 40 mg/dL), patients with high HDL cholesterol levels (≥ 60 mg/dL) had a lower risk of future RAO development with a hazard ratio (95% confidence intervals) of 0.78 (0.73-0.83) in the age and sex-adjusted model and 0.88 (0.83-0.95) in the full-adjusted model. The younger subgroup (< 60 years) had an HR of 0.81 in the high HDL cholesterol group compared to the low HDL cholesterol group, while the older subgroup (≥ 60 years) had an HR of 0.93 (p for interaction = 0.012). CONCLUSION Low HDL cholesterol level is an independent risk factor for the development of RAO.

To report 20-year trends in incidence and survival of vulvar cancer in Korea.Using data from the Korean Central Cancer Registry, age-standardized incidence rates (ASRs) and annual percentage changes (APCs) were calculated. Net survival (NS) was estimated by the Pohar-Perme method, and conditional net survival (CNS) was calculated.A total of 2221 patients was diagnosed with vulvar cancer during the 1999-2018 period, with an ASR of 0.32 per 100,000 person-years. Among the cases, 51.4% were squamous cell carcinoma (SqCC), 21.3% were Paget disease, and 8.6% were basal cell carcinoma (BCC). There was an increase in incidence for all vulvar cancer (APC 2.4%, 95% CI 1.8-3.0). However, although BCC (APC 7.0%, 95% CI 3.3-10.8) and Paget disease (APC 5.9%, 95% CI 4.2-7.6) increased, SqCC did not (APC 0.2%, 95% CI -0.8-1.2). There was an increase in incidence in all age groups. The 5Y NS was 74.0% overall, and it did not improve significantly during the study period. The 5Y CNS of vulvar cancer increased continuously with time survived: from 74.0% (71.4-76.4) at baseline to 98.1% (95% CI, 85.4-99.8) at 5 years after diagnosis.The incidence of vulvar cancer in Korea showed a different pattern from those in the US and Europe: SqCC incidence was relatively low and remained stable, but the incidence of BCC and Paget's disease increased. Survival did not improve in the past two decades. Patients can be considered cured after surviving for 5 years.