Association Between Various Types or Statuses of Smoking and Subjective Cognitive Decline Based on a Community Health Survey of Korean Adults.

Objectives: The relationship between smoking and subjective cognitive decline (SCD), which is defined as the subjective perception of cognitive decline, is not well known. This study aimed to investigate the relationship of various types of smoking, including E-cigarette smoking and the use of E-liquid, with the incidence of SCD among Korean adults. Methods: We evaluated the 2018 Korean Community Health Survey data collected from community-dwelling people in Korea. A total of 104,453 non-smokers, 38,607 past smokers, and 26,776 current smokers with eligible data were included in the study. SCD was assessed using the Behavioral Risk Factor Surveillance System. The past or current smoking pack-years throughout each participant's entire life were calculated. Multiple regression analyses were carried out to estimate the adjusted odds ratios (ORs) as measures of the association between each type of smoking and SCD after adjustment for potential confounders. Results: Compared to no exposure, passive smoking was associated with higher odds of SCD. Compared to non-smokers, past smokers had a higher OR for SCD; however, current smokers did not. There were no significant associations between passive smoking and SCD in the non-smoker and past smoker groups, but there was a significant relationship between them in the current smoker group. While the cumulative dose of smoking was correlated with an increased OR of SCD in each group of current smokers and past smokers, E-cigarette smoking and the use of E-liquid were not associated with higher ORs in the current smoker group. Conclusion: Our findings support that passive smoking and past smoking are significantly associated with SCD and that more cumulative exposure to smoking is correlated with a higher OR of SCD.

The Association of Pre-existing Diagnoses of Alzheimer's Disease and Parkinson's Disease and Coronavirus Disease 2019 Infection, Severity and Mortality: Results From the Korean National Health Insurance Database.

Objectives: Despite the numerous studies on coronavirus disease 2019 (COVID-19), data regarding the impact of pre-existing diagnoses of Alzheimer's disease (AD) and Parkinson's disease (PD) on the susceptibility to and outcome of COVID-19 are limited. We aimed to determine whether patients with AD/PD had a higher likelihood of contracting COVID-19 and experiencing worse outcomes. Methods: Data from patients with confirmed diagnoses of COVID-19 (n = 8,070) from January to June 2020 and control participants (n = 121,050) who were randomly selected to match the patients on the basis of age and sex were extracted from the Korean National Health Insurance Database. Pre-existing diagnoses of AD and PD were identified based on medical claim codes. The associations of pre-existing AD or PD with contracting COVID-19, developing severe COVID-19 and dying due to COVID-19 were examined using a logistic regression model. The participants' age, sex, income, comorbidity score, and history of hypertension/diabetes were assessed as covariates. Results: COVID-19 cases were more likely to have a pre-existing AD diagnosis (adjusted odds ratio [aOR] = 2.11, 95% confidence interval [CI] = 1.79-2.50, P-value < 0.001) than controls. COVID-19 cases were more likely to have a pre-existing PD diagnosis than controls, although this estimate did not quite reach statistical significance (aOR = 1.41, 95% CI = 1.00-2.00, P-value = 0.054). Pre-existing AD was related to severe disease and mortality from COVID-19 (aOR = 2.21, 95% CI = 1.64-2.98; aOR = 2.21, 95% CI = 1.00-2.00). Pre-existing PD was not associated with mortality (aOR = 1.54, 95% CI = 0.75-3.16) but was associated with severe disease (aOR = 2.89, 95% CI = 1.56-5.35). Conclusion: We found that COVID-19 infection was significantly associated with a pre-existing diagnosis of AD but not with a pre-existing diagnosis of PD. Patients with pre-existing AD had higher odds of developing severe COVID-19 and dying. Pre-existing PD was only associated with a higher odds of developing severe COVID-19.

Physical Activity Is Associated with a Lower Risk of Osteoporotic Fractures in Osteoporosis: A Longitudinal Study.

The purpose of our study was to examine the occurrence of osteoporotic fractures (fxs) according to the level of physical activity (PA) among osteoporosis using the Korean National Health Insurance Service (NHIS) customized database. From NHIS data from 2009 to 2017, osteoporosis was selected as requested. PA was classified into 'high PA' (n = 58,620), 'moderate PA' (n = 58,620), and 'low PA' (n = 58,620) and were matched in a 1:1:1 ratio by gender, age, income within the household unit, and region of residence. A stratified Cox proportional hazard model was used to calculate hazard ratios (HRs) for each type of fx comparing PA groups. The 'low PA' group was the reference group. For vertebral fx, the adjusted HR (95% confidence intervals (CIs)) was 0.27 (0.26-0.28) for the 'high PA' group and 0.43 (0.42-0.44) for the 'moderate PA' group. For hip fx, the adjusted HR (95% CIs) was 0.37 (0.34-0.40) for the 'high PA' group and 0.51 (0.47-0.55) for the 'moderate PA' group. For distal radius fx, the adjusted HR (95% CIs) was 0.32 (0.30-0.33) for the 'high PA' group and 0.46 (0.45-0.48) for the 'moderate PA' group. The results of this study suggest that a higher intensity of PA is associated with a lower risk of osteoporotic fxs, including vertebral fx, hip fx, and distal radius fx.

The Association Between Thyroid Diseases and Alzheimer's Disease in a National Health Screening Cohort in Korea.

Objectives: Thyroid dysfunction is linked to an increased risk of cognitive impairment. However, studies on the relationships between thyroid diseases and Alzheimer's disease (AD) have reported conflicting results. We investigated the associations between several thyroid diseases and AD in a nested case-control study. Methods: A total of 1,977 participants with AD were identified by claims data from 2002-2015 among a random sample of half a million people in the Korean National Health Insurance database. We recruited 16,473 age- and sex-matched (1:4 ratio) control participants and applied conditional logistic regression to estimate the relationships between thyroid diseases and AD, with adjustments for potential confounders, such as basic demographics, lifestyle factors, and various medical conditions or comorbidities. Results: The prevalence rates of hypothyroidism (odds ratio [OR]=1.14, 95% confidence interval [CI]=1.00-1.30), thyroiditis (OR=1.22, 95% CI=1.05-1.40), and hyperthyroidism (OR=1.13, 95% CI=1.01-1.28) were significantly higher in participants with AD than in control participants after adjustment for confounders. Conclusion: In this large national sample, we found significant relationships between several thyroid diseases and AD. Despite of the need for further investigation, these findings could better support to appreciate the pathophysiology of AD.

The Effects of Previous Thyroid Disease on the Susceptibility to, Morbidity of, and Mortality Due to COVID-19: A Nationwide Cohort Study in South Korea.

This study aimed to investigate the associations of the susceptibility to, morbidity of, and mortality due to coronavirus disease 2019 (COVID-19) with thyroid diseases. Korea National Health Insurance Database Coronavirus disease 2019 (NHID-COVID-19) medical claim code data from 2015 to 2020 were analyzed. A total of 8070 COVID-19 patients and 32,280 matched control participants were evaluated for histories of hypothyroidism, hyperthyroidism, Graves' disease, thyroiditis, and autoimmune thyroiditis. The relationships of susceptibility to, morbidity of, and mortality due to COVID-19 with hypothyroidism, hyperthyroidism, Graves' disease, thyroiditis, and autoimmune thyroiditis were analyzed using a conditional logistic regression. Hypothyroidism, hyperthyroidism, Graves' disease, thyroiditis, and autoimmune thyroiditis were not associated with susceptibility to, morbidity of, or mortality due to COVID-19. Graves' disease was related to higher odds of mortality due to COVID-19 in the adjusted model but the confidence interval (CI) was wide, probably due to the small number of deaths among patients with Graves' disease (aOR = 11.43, 95% CI = 1.29-101.22, p = 0.029). Previous histories of hypothyroidism, hyperthyroidism, Graves' disease, thyroiditis, and autoimmune thyroiditis were not related to susceptibility to COVID-19. In addition, prior histories of thyroid diseases were not related to increased risks of COVID-19-related morbidity and mortality.

Analyses of the association between cervical cancer and osteoporosis/osteoporotic fracture: a cross-sectional study using KoGES HEXA data.

BACKGROUND: This study aimed to evaluate the association between cervical cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES). METHODS: In this national cohort study using KoGES health examination (HEXA) data, we extracted data for patients with cervical cancer (n = 493) and control participants (n = 77,571); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs). RESULTS: The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.49 (95% CI 1.15-1.92, p = 0.03) and 1.06 (95% CI 0.82-1.38, p = 0.634), respectively, in the cervical cancer group. The ORs (95% CIs) for osteoporosis were 2.12 (95% CI 1.14-3.95, p = 0.018) in the ≤ 51-year-old group and 1.43 (95% CI 1.08-1.89, p = 0.011) in the ≥ 52-year-old group of cervical cancer patients. CONCLUSION: We concluded that Korean women with cervical cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture.

The Association between Anemia and Parkinson's Disease: A Nested Case-Control Study Using a National Health Screening Cohort.

(1) Background: Controversy exists regarding the relationship between anemia and Parkinson's disease (PD). This study aimed to evaluate the risk of PD related to anemia in the Korean population. (2) Methods: The Korean National Health Insurance Service-National Sample Cohort, which includes adults over 40 years of age, was assessed from 2002 to 2015. A total of 5844 PD patients were matched by age, sex, income, and region of residence with 23,376 control participants at a ratio of 1:4. The analyzed covariates included age, sex, blood pressure, fasting blood glucose, obesity, smoking status, and alcohol consumption. A multiple logistic regression analysis was conducted for case-control analyses. (3) Results: The adjusted odds ratio (OR) for the risk of PD associated with anemia was 1.09 after adjusting for potential confounders (95% confidence interval (CI) 1.01-1.18, p = 0.030). Among men younger than 70 years, the adjusted OR of PD was 1.34 (95% CI 1.13-1.60, p = 0.001). (4) Conclusions: Our findings suggest that anemia may increase the risk of PD, particularly in men younger than 70 years. Further research is required to elucidate the causal relationship between these two diseases.

Analyses of the association between breast cancer and osteoporosis/fracture history: a cross-sectional study using KoGES HEXA data.

We performed a nationwide, population-based cohort study to evaluate the risk of osteoporosis and osteoporotic fracture in patients with breast cancer using the data from Korean Genome and Epidemiology Study (KoGES) and concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, regardless of age. PURPOSE: This study aimed to evaluate the association between breast cancer and the occurrence of osteoporosis and osteoporotic fracture using data from the Korean Genome and Epidemiology Study (KoGES). METHODS: Using the national KoGES health examinee (HEXA) data consisting of data from urban resident participants ≥ 40 years old, we extracted data for patients with breast cancer (n = 1080) and for control participants (n = 106,993); we then analyzed the occurrence of osteoporosis and osteoporotic fracture at baseline from 2004 to 2013 and during follow-up from 2012 to 2016. A logistic regression model was used to analyze the odds ratios (ORs) and the 95% confidence intervals (CIs). Subgroup analysis was performed based on age (younger group aged ≤ 51 years old; older group aged ≥ 52 years old). RESULTS: The ORs (95% CIs) for osteoporosis and osteoporotic fracture were 1.54 (95% CI = 1.28-1.84, P < 0.001) and 1.01 (95% CI = 0.82-1.23, P = 0.949), respectively, in the breast cancer group. In the subgroup analysis based on age, the ORs (95% CIs) for osteoporosis were 2.41 (95% CI = 1.70-3.43, P < 0.001) in the younger group and 1.33 (95% CI = 1.08-1.64, P = 0.007) in the older group of breast cancer patients. The ORs (95% CIs) for osteoporotic fracture were 1.15 (95% CI = 0.81-1.63, P = 0.441) in the younger group and 0.95 (95% CI = 0.74-1.21, P = 0.661) in the older group of breast cancer patients. CONCLUSION: We concluded that Korean women with breast cancer had a higher risk of osteoporosis than healthy women, but the same finding was not observed for osteoporotic fracture, regardless of age.

Association between sleep quality and subjective cognitive decline: evidence from a community health survey.

OBJECTIVES: Little is known concerning whether subjective cognitive decline (SCD) is associated with sleep quality. This study aimed to identify the association between self-reported quality of sleep and SCD in a large population of middle-aged and older adults in Korea. METHODS: We conducted this study based on data collected from the 2018 Korean Community Health Survey. Individuals aged 40 years and older who responded to the Behavioral Risk Factor Surveillance System (BRFSS) and Pittsburgh Sleep Quality Index (PSQI) assessments and did not lack data about multiple covariates were included. A total of 37,712 respondents with SCD and 135,119 those without SCD were included. Sleep quality was estimated using the PSQI, which includes seven self-reported components for sleep health assessment. SCD was assessed using the BRFSS. Logistic regression models adjusted for confounders were used to examine whether each component of the sleep quality index was related to SCD. Additional analysis of the correlation between quantified scores for each component and SCD-related functional limitations as ordinal variables was performed. RESULTS: The mean age was 62.7 years in the SCD group and 56.4 years in the control group. In total, 13,777 (28.9%) respondents were male in the SCD group and 62,439 (50.7%) in the control group. The adjusted odds ratios of SCD were 1.25 for very bad sleep quality, 1.26 for long sleep latency, 1.16 for <5 h of sleep duration, 1.08 for <65% habitual sleep efficiency, 2.29 for high sleep disturbance, 1.26 for use of sleep medication ≥3 times a week, and 2.47 for high daytime dysfunction due to sleep problems compared to good sleep conditions. Furthermore, a higher score for each component of the sleep quality index correlated with greater SCD-related functional limitations. CONCLUSIONS: Our study provides evidence that poor sleep quality is closely related to both SCD and SCD-related functional limitations.

Association between Previous Statin Use and Alzheimer's Disease: A Nested Case-Control Study Using a National Health Screening Cohort.

A number of studies report the incidence of Alzheimer's disease (AD) in patients taking statins, but the results are inconsistent. (1) Background: The present study investigated the cross-sectional association between previous statin use and the risk of AD development in Korean residents. (2) Methods: We used the Korean National Health Insurance Service-National Sample Cohort; 17,172 AD patients were matched by age, gender, income, and region of residence with 68,688 control participants at a ratio of 1:4. We used a multiple conditional logistic regression model to analyse the association between the number of days of statin use and AD occurrence. Further analyses were performed to identify whether this association is maintained for different ages, genders, socioeconomic status groups, and covariates. (3) Results: The odds ratio, which was adjusted for potential confounders, for the days of statin use per year in the AD group compared to the control group was 0.95 (95% confidence interval = 0.92-0.98; p = 0.003). The number of days of statin use in the AD group was significantly smaller in the subgroups of non-smokers and individuals with normal weight, alcohol consumption less than once a week, total cholesterol level below 200 mg/dL, systolic blood pressure below 140, diastolic blood pressure below 90, and fasting blood glucose below 100 mg/dL. (4) Conclusions: Our results suggest that statin use prevents the occurrence of AD. The effects of statin use in preventing AD may be greater in individuals at relatively low risk.

Associations between Physical Activity, Sunshine Duration and Osteoporosis According to Obesity and Other Lifestyle Factors: A Nested Case-Control Study.

(1) Background: The purpose of the study was to evaluate the associations between physical activity (PA), sunshine duration (SD) and the occurrence of osteoporosis according to lifestyle status. (2) Methods: Data from the Korean National Health Insurance Service-National Sample Cohort (NHIS-NSC) collected from 2009 to 2015 were used. Osteoporosis (n = 19,351) and control (n = 38,702) participants were matched in a 1:2 ratio according to age, sex, income, and region of residence. PA was classified as moderate- to high-intensity PA (MHPA) or low-intensity PA (LPA) based on the International Physical Activity Questionnaire (IPAQ). SD was classified as short (≤6 h) or long (>6 h). Conditional logistic regression was used to calculate the odds ratios (ORs) with 95% confidence intervals (CIs) of MHPA and long SD for the occurrence of osteoporosis. Subgroup analyses were performed according to SD (or PA), obesity, smoking, and alcohol consumption. (3) The adjusted OR of MHPA for osteoporosis was 0.90 (95% CI = 0.87-0.94). The results were consistent in the age/sex, SD, obesity, smoking, and alcohol consumption subgroups, but not the <60-year-old male and underweight subgroups. The adjusted OR of long SD for osteoporosis was 0.96 (95% CI = 0.93-1.00). The findings were consistent in the <60-year-old female, obese, nonsmoker, and <1 time a week alcohol consumption subgroups. (4) Conclusions: We suggest that both higher intensity of PA and long SD could decrease the risk of osteoporosis. Specifically, PA could decrease the risk of osteoporosis in individuals with most characteristics except male sex or underweight. Long SD could decrease the risk of osteoporosis in young females, obese individuals, nonsmokers, and individuals with lower alcohol consumption.

Association between Chronic Obstructive Pulmonary Disease and Ménière's Disease: A Nested Case-Control Study Using a National Health Screening Cohort.

This study explored the relation between Ménière's disease and chronic obstructive pulmonary disease (COPD). The ≥40-year-old population of the Korean National Health Insurance Service-Health Screening Cohort was included. In total, 7734 Ménière's disease patients and 30,936 control participants were enrolled. Control participants were matched for age, sex, income, and region of residence with Ménière's disease participants. The odds of having Ménière's disease given a history of COPD were analyzed using conditional logistic regression. Subgroup analyses were conducted according to age, sex, income, and region of residence. The odds of having Ménière's disease were found to be 1.18-fold higher with a history of COPD than with no history of COPD (95% confidence intervals (CI) = 1.06-1.32, E-value (CI) = 1.64 (1.31)). The ≥60 years old, male, low-income, and rural subgroups showed increased odds of developing Ménière's disease when a history of COPD was reported. A history of COPD was associated with an increased risk of Ménière's disease in the adult population.

Association Between Thyroid Diseases and Parkinson's Disease: A Nested Case-Control Study Using a National Health Screening Cohort.

BACKGROUND: Although the dopaminergic system is interconnected with the hypothalamic-pituitary-thyroid axis, few studies have explained the causal relationship between thyroid disease and Parkinson's disease (PD). OBJECTIVE: The goal of this study was to investigate the association between thyroid diseases and PD in Korean residents. METHODS: The Korean National Health Insurance Service-National Sample Cohort, which includes individuals aged ≥40 years, was assessed from 2002 to 2015. A total of 5,586 PD patients were matched by age, sex, income, and the region of residence with 22,344 control participants at a ratio of 1:4. In the PD and control groups, previous histories of levothyroxine treatment, goiter, hypothyroidism, thyroiditis, and hyperthyroidism were investigated. RESULTS: The rates of levothyroxine treatment for more than 3 months, hypothyroidism, and hyperthyroidism were higher in the PD group than the control group (3.2%, 3.8%, and 2.8% vs. 2.5%, 2.9%, and 1.9%, respectively, p < 0.05). The adjusted odds ratios (ORs) in model 2, which was adjusted for all potential confounders, for hypothyroidism and hyperthyroidism in the PD group were 1.25 (95% confidence interval (CI) 1.01-1.55, p = 0.044) and 1.37 (95% CI 1.13-1.67, p = 0.002), respectively. In subgroup analyses, the association between hypothyroidism and PD was maintained in men older than 70 years and the association between hyperthyroidism and PD was maintained in women younger than 70 years. CONCLUSION: Both hyperthyroidism and hypothyroidism were associated with higher risk of PD, particularly for women younger than 70 years and men older than 70 years, respectively.

Increased risk of osteoporosis in patients with peptic ulcer: a follow-up study using a national sample cohort.

We performed a nationwide, population-based cohort study to investigate the risk of osteoporosis in patients with peptic ulcer disease in South Korea and concluded that peptic ulcer disease is associated with an increased risk of osteoporosis. PURPOSE: This study aimed to evaluate the association between peptic ulcer disease (PUD) and the occurrence of osteoporosis using a national sample cohort from South Korea. METHODS: Using the national cohort study from the Korean National Health Insurance Service, we extracted data for patients with PUD (n = 50,002) and for 1:1 matched control participants (n = 50,002); we then analyzed the occurrence of osteoporosis from 2002 to 2013. The patients were matched according to age, sex, income, region of residence, and past medical history. A stratified Cox proportional hazards model was used to analyze the hazard ratios (HRs) and the 95% confidence intervals (CIs). Subgroup analyses were performed based on age and sex. RESULTS: The adjusted HR for osteoporosis was 1.36 (95% CI = 1.33-1.40, P < 0.001) in the PUD group. In the subgroup analysis based on age and sex, the respective adjusted HRs of PUD for osteoporosis were 1.33 (95% CI = 1.21-1.47) in the < 65-year-old group of men and 1.42 (95% CI = 1.30-1.56) in the ≥ 65-year-old group of men (each P < 0.001). The respective adjusted HRs of PUD for osteoporosis were 1.34 (95% CI = 1.29-1.39) in the < 65-year-old group of women and 1.38 (95% CI = 1.33-1.47) in the ≥ 65-year-old group of women (each P < 0.001). CONCLUSION: In the current nationwide cohort study, we found that PUD is associated with an increased risk of osteoporosis regardless of sex.