OBJECTIVE: Although some reproductive and metabolic characteristics of polycystic ovary syndrome (PCOS) are known risk factors for breast cancer, the evidence regarding a potential association between PCOS and breast cancer is scarce. In this population-based cohort study including all 1,719,452 women born in Denmark between 1940 and 1993, we investigated the association between PCOS and breast cancer.
METHODS: PCOS diagnoses, cancer diagnoses, covariates, migrations, and vital status were all obtained from national population and health registers. Hazard ratios (HR) and 95% confidence intervals (CI) for breast cancer overall and for histological subtypes separately were calculated based on adjusted cox proportional hazards models.
RESULTS: During a median follow-up of 26 years, 63,078 women were diagnosed with breast cancer. We found an increased risk of breast cancer overall among women with PCOS compared with women without PCOS (HR: 1.21, 95% CI 1.02-1.44). In analyses stratified for menopausal status, the increased risk was restricted to postmenopausal women (HR: 1.63, 95% CI 1.23-2.15). The results for ductal and lobular histological subtypes analyses separately resembled those observed for breast cancer overall.
CONCLUSIONS: This is the first study to report an increased risk of breast cancer among women with a history of PCOS. The increased risk was seemingly confined to postmenopausal women. Our results therefore contribute to an increased knowledge of the etiology of breast cancer, but our findings should be further confirmed in other large cohort studies with an appropriately long follow-up period.

This retrospective study investigated the incidence, medication use, and outcomes in pediatric autosomal-dominant polycystic kidney disease (ADPKD) using Taiwan\'s National Health Insurance Research Database (NHIRD). A 1:4 matched control group of individuals included in the NHIRD during the same period was used for comparative analyses. A total of 621 pediatric patients were identified from 2009 to 2019 (mean age, 9.51 ± 6.43 years), and ADPKD incidence ranged from 2.32 to 4.45 per 100,000 individuals (cumulative incidence, 1.26-1.57%). The incidence of newly developed hypertension, anti-hypertensive agent use, nephrolithiasis, and proteinuria were significantly higher in the ADPKD group than the non-ADPKD group (0.7 vs. 0.04, 2.26 vs. 0.30, 0.4 vs. 0.02, and 0.73 vs. 0.05 per 100 person-years, respectively). The adjusted hazard ratios for developing hypertension, proteinuria, nephrolithiasis and anti-hypertensive agent use in cases of newly-diagnosed pediatric ADPKD were 12.36 (95% CI 4.92-31.0), 13.49 (95% CI 5.23-34.79), 13.17 (95% CI 2.48-69.98), and 6.38 (95% CI 4.12-9.89), respectively. The incidence of congenital cardiac defects, hematuria, urinary tract infections, gastrointestinal diverticulosis, dyslipidemia, and hyperuricemia were also higher in the ADPKD group. Our study offers valuable insights into the epidemiology of pediatric ADPKD in Taiwan and could help in formulating guidelines for its appropriate management.

OBJECTIVE: Epistaxis is a common condition that affects about 60% of the population in their lifetime, with 6% needing medical attention. Little is known about the epidemiology and risk factors of epistaxis outside the health care system. This study aimed to investigate the prevalence and risk factors of epistaxis in a rural Danish population using data from the Lolland-Falster Health Study (LOFUS).
METHODS: We conducted a cross-sectional survey based on data from LOFUS, a household-based, prospective cohort study in the rural provincial area of Lolland-Falster, Denmark. We enrolled 10,065 participants (≥ 50 years) and collected data on demographics, comorbidities, medication, lifestyle factors, and laboratory parameters. Logistic regressions were used to test for correlations between epistaxis and different risk factors.
RESULTS: In total 5.3% of the participants had experienced epistaxis within the past 30 days, and 7.9% had sought medical attention for epistaxis at some point in their lives. We identified several factors that were significantly correlated with increased odds of epistaxis, such as male gender, age group 50-59 years, high BMI (> 25), allergy, diabetes, hypertension, atherosclerosis, angina, and anticoagulant treatment. Excellent or good self-reported health was correlated to significantly lower odds of epistaxis.
CONCLUSIONS: This study provides a comprehensive overview of the prevalence and risk factors of epistaxis outside the health care system. Our study suggests that preventive measures targeting these risk factors may reduce the incidence and severity of epistaxis in this population.

This population-based cohort study evaluated the association between current use of oral contraceptives (OC) among women under 50 years (n=306,541), and hormone therapy (HT) among women aged 50 or older (n=323,203), and COVID-19 infection and hospitalization. Current OC/HT use was recorded monthly using prescription dispensing data. COVID-19 infections were identified March 2020-February 2021. COVID-19 infection and hospitalization were identified through diagnosis codes and laboratory tests. Weighted generalized estimating equations models estimated multivariable-adjusted odds ratios (aORs) for COVID-19 infection associated with time-varying OC/HT use. Among women with COVID-19, logistic regression models evaluated OC/HT use and COVID-19 hospitalization. Over 12 months, 11,727 (3.8%) women <50 years and 8,661 (2.7%) women ≥50 years experienced COVID-19 infections. There was no evidence of an association between OC use and infection (aOR=1.05; 95%CI: 0.97, 1.12). There was a modest association between HT use and infection (aOR=1.19; 95%CI: 1.03, 1.38). Women using OC had a 39% lower risk of hospitalization (aOR=0.61; 95%CI: 0.38, 1.00), but there was no association of HT use with hospitalization (aOR=0.89; 95%CI: 0.51, 1.53). These findings do not suggest a meaningfully greater risk of COVID-19 infection associated with OC or HT use. OC use may be associated with lower COVID-19 hospitalization risk.

Although the effectiveness and safety of ticagrelor versus clopidogrel may differ in patients with chronic liver disease, there is a scarcity of evidence comparing ticagrelor and clopidogrel in patients with chronic liver disease. We aimed to evaluate the risk of major adverse cardiovascular events (MACE) and major bleeding associated with ticagrelor versus clopidogrel in patients undergoing percutaneous coronary intervention (PCI) due to acute coronary syndrome by chronic liver disease status.
Using the Korean healthcare claim database, we included adult patients who underwent PCI and initiated ticagrelor or clopidogrel treatment within 7 days of an acute coronary syndrome diagnosis. Patients were classified into 2 mutually exclusive groups: patients with chronic liver disease and patients without chronic liver disease. Within each group, the hazard ratios (HRs) with 95% confidence intervals (CIs) of MACE and major bleeding associated with ticagrelor versus clopidogrel were calculated using a Cox proportional hazards model within a 1:1 propensity score (PS) matched cohort.
The final cohort included 14,261 and 148,535 patients with and without chronic liver disease, respectively. After PS matching, the risk of MACE (with chronic liver disease, HR: 1.01, 95% CI: 0.91-1.13; without chronic liver disease, HR: 1.02, 95% CI: 0.98-1.05; P for homogeneity: 0.865) and major bleeding (with chronic liver disease, HR: 1.07, 95% CI: 0.71-1.61; without chronic liver disease, HR: 1.32, 95% CI: 1.15-1.53; P for homogeneity: 0.342) for ticagrelor versus clopidogrel do not vary with chronic liver disease status.
Among acute coronary syndrome patients undergoing PCI, the use of ticagrelor versus clopidogrel was associated with a similar risk of MACE and an increased risk of major bleeding, but these risks did not vary with chronic liver disease status.

BACKGROUND: Evidence exists that lowering high blood pressure reduces the risk of dementia. However, the generalizability of this evidence to old patients from the general population remains uncertain.
OBJECTIVE: This study sought to evaluate the effect of antihypertensive drug treatment on the risk of dementia in a heterogeneous group of new users of antihypertensive drugs.
METHODS: A nested case-control study was carried out by including the cohort of 215,547 patients from Lombardy, Italy, aged ≥65 years, who started taking antihypertensive drugs between 2009 and 2012. Cases were the 13,812 patients (age 77.5 ± 6.6 years; 40% men) who developed dementia or Alzheimer\'s disease during follow-up (up to 2019). For each case, 5 control subjects were selected to be matched for sex, age, and clinical status. Exposure to drug therapy was measured by the proportion of the follow-up covered by antihypertensive drugs. Conditional logistic regression was used to model the outcome risk associated with exposure to antihypertensive drugs.
RESULTS: Exposure to treatment was inversely associated with the risk of dementia. Compared with patients with very low exposure, those with low, intermediate, and high exposure exhibited a 2% (95% CI: -4% to 7%), 12% (95% CI: 6%-17%), and 24% (95% CI: 19%-28%) risk reduction, respectively. This was also the case for very old (aged ≥85 years) and frail patients (ie, those characterized by a high mortality risk at 1 year).
CONCLUSIONS: In the old fraction of the general population, antihypertensive drug treatment is associated with a lower risk of dementia. This was also the case in very old and frail patients.

Results from previous studies examining the association between fertility treatment and borderline ovarian tumors are inconsistent. The aim of this study was to investigate the association between fertility treatment and borderline ovarian tumors in a cohort of infertile women.
This cohort study was based on the Danish Infertility Cohort and included all infertile women aged 20-45 years living in Denmark between 1 January 1995 and 31 December 2017 (n = 146,891). Information on use of fertility drugs, borderline ovarian tumors and cancer diagnoses, covariates, emigration, and vital status was obtained by linkage to national registers. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) with adjustment for potential confounders for overall borderline ovarian tumors and for serous- and mucinous borderline ovarian tumors separately.
During a median 11.3 years of follow-up, 144 women developed a borderline ovarian tumor. No marked associations between ever use of clomiphene citrate, gonadotropins, gonadotropin-releasing hormone receptor modulators, human chorionic gonadotropin or progesterone and borderline ovarian tumors were observed, neither overall nor for serous and mucinous borderline ovarian tumors analysed separately. Further, no clear associations with borderline ovarian tumors were found according to cumulative dose, time since first use or parity status for any fertility drugs.
No marked associations between use of fertility drugs and borderline ovarian tumors were observed. However, the cohort\'s relatively young age at end of follow-up emphasizes the importance of extending the follow-up period for women who have used fertility drugs.

UNASSIGNED: Autism spectrum disorder (ASD) may be associated with increased mortality, but relevant findings have been inconsistent. The modifying effects of gender and intellectual disability on excess mortality in individuals with ASD are underexplored.
UNASSIGNED: Using Taiwan\'s National Health Insurance Research Database and the National Death Registry, this population-based cohort study selected the data of 75,946 patients with ASD (ASD cohort) and 75,946 age group-, gender-, and income-matched (1:1) patients without ASD (non-ASD cohort). Cox proportional hazards models were used to compare mortality rates between the cohorts, and stratified analyses were used to evaluate the influence of gender and intellectual disability on mortality risk.
UNASSIGNED: The ASD cohort had higher mortality rates for all causes of death than did the non-ASD cohort (adjusted hazard ratio 1.64, 95% confidence interval 1.54-1.75). Comorbid intellectual disability was associated with an increased risk of mortality, and this association was stronger in female patients than in male patients. Moreover, when focusing on deaths from natural causes, we found a significantly higher odds ratio for mortality in the ASD population with ID compared to those without ID.
UNASSIGNED: ASD is associated with increased mortality, especially among female individuals and those with intellectual disability.

Taiwan provided several COVID-19 vaccine platforms: mRNA (BNT162b2, mRNA-1273), adenoviral vector-based (AZD1222), and protein subunit (MVC-COV1901). After Taiwan shifted from its zero-COVID strategy in April 2022, population-based evaluation of vaccine effectiveness (VE) became possible. We conducted an observational cohort study of 21,416,151 persons to examine VE against SARS-CoV-2 infection, moderate and severe illness, and death during March 22, 2021-September 30, 2022. After adjusting for age and sex, we found that persons who completed 3 vaccine doses (2 primary, 1 booster) or received MVC-COV1901 as the primary series had the lowest hospitalization incidence (0.04-0.20 cases/100,000 person-days). We also found 95.8% VE against hospitalization for 3 doses of BNT162b2, 91.0% for MVC-COV1901, 81.8% for mRNA-1273, and 65.7% for AZD1222, which had the lowest overall VE. Our findings indicated that protein subunit vaccines provide similar protection against SARS-CoV-2---associated hospitalization as mRNA vaccines and can inform mix-and-match vaccine selection in other countries.

BACKGROUND: Little is known about the impact of physical activity (PA) and PPSV23 vaccination on pneumonia-related hospitalizations. This study examined the association between regular PA and pneumonia-related hospitalization according to PPSV23 vaccination status in older adults.
METHODS: This retrospective cohort study was conducted using health checkup data, medical care claims data, and vaccination records from two Japanese municipalities. Residents aged ≥65 years who had undergone a health checkup between April 2016 and March 2021 were categorized into a PPSV23 vaccinated or unvaccinated cohort. Each cohort was further divided into a PA group and no PA group. The hazard ratio (HR) of PA for pneumonia-related hospitalization was calculated for each cohort while adjusting for sex, age, comorbidities, and metabolic syndrome.
RESULTS: The vaccinated cohort comprised 16,295 participants (no PA: 5,139, PA: 11,156), and the unvaccinated cohort comprised 7,998 participants (no PA: 2,671, PA: 5,327). In the vaccinated cohort, the PA group had a significantly lower hazard for pneumonia-related hospitalization than the no PA group (adjusted HR: 0.58, P = 0.004). However, PA was not associated with pneumonia-related hospitalization in the unvaccinated cohort (adjusted HR: 0.70, P = 0.270).
CONCLUSIONS: PA can reduce the risk of pneumonia-related hospitalization in vaccinated persons. Interventions that increase both vaccination rates and PA habits may help to reduce these hospitalizations in older adults.