Risk of depression in amyotrophic lateral sclerosis: A nationwide cohort study in South Korea.

Depression is frequently reported in amyotrophic lateral sclerosis (ALS) due to the disastrous prognosis of progressive motor impairment, but the risk of depression in ALS is still unclear. Therefore, we investigated the risk of depression in ALS and analyzed the effect of ALS-related physical disability on the risk of developing depression using the Korean National Health Insurance Service (KNHIS) database. A total of 2241 ALS patients, as defined by the International Classification Diseases (ICD, G12.21) and Rare Intractable Disease codes (V123), and 1:10 sex- and age-matched controls were selected from the KNHIS. After applying exclusion criteria (non-participation in national health screening, history of depression, or having missing data), 595 ALS patients and 9896 non-ALS individuals were finally selected. Primary outcome is newly diagnosed depression during follow-up duration defined by ICD code (F32 or F33). A Cox regression model was used to examine the hazard ratios (HRs) after adjustment for potential confounders. During the follow-up period, 283 cases of depression in the ALS group and 1547 in the controls were recorded. The adjusted HR for depression in ALS was 9.1 (95% confidence interval [CI] 7.87-10.60). The risk of depression was slightly higher in the disabled ALS group (aHR 10.1, 95% CI 7.98-12.67) than in the non-disabled ALS group (aHR 8.78, 95% CI 7.42-10.39). The relative risk of depression was higher in younger patients than in older patients, and in obese patients than in non-obese patients. Our study showed that ALS patients have an increased risk of depression compared to non-ALS individuals.

Assessment of current practices and perceived effectiveness of injectable polynucleotide for enlarged facial pores among cosmetic physicians: A survey-based evaluation.

BACKGROUND: Polynucleotides stimulate collagen formation and are used clinically to enhance elasticity. In this study, we investigated current practices and perceived effectiveness of polynucleotide injection treatment for enlarged facial pores among cosmetic physicians. MATERIALS AND METHODS: A survey was developed to investigate clinicians' use and effectiveness of polynucleotides in the treatment of enlarged facial pores. This survey was distributed to clinicians at the Korean Aesthetic Surgery & Laser Society Autumn Symposium. RESULTS: A total of 407 physicians who used polynucleotides for enlarged facial pores were enrolled in the survey. Polynucleotides were used by 75.7%, 87.7%, and 72.2% of physicians for enlarged facial pores caused by excessive sebum production, reduced elasticity, and acne, respectively. Among those users, 81.4%, 83.8%, and 76.8% in those same categories, respectively, responded that polynucleotides were "very effective" or "effective." Furthermore, most clinicians combined polynucleotides with microneedle radiofrequency as energy-based devices and with botulinum toxin as injection therapy. CONCLUSION: This study highlights the widespread use and perceived efficacy of polynucleotide injection among cosmetic physicians in the Republic of Korea for enlarged facial pores due to excessive sebum production, reduced elasticity, and acne. Positive feedback from practitioners supports the benefits of using polynucleotides in enlarged facial pore treatment.

Weight Change After Cancer Diagnosis and Risk of Diabetes Mellitus: A Population-Based Nationwide Study.

Purpose: Cancer survivors are at increased risk of diabetes mellitus (DM). Additionally, the prevalence of obesity, which is also a risk factor for DM, is increasing in cancer survivors. We investigated the associations between weight change after cancer diagnosis and DM risk. Materials and Methods: This retrospective cohort study used data from the Korean National Health Insurance Service. Participants who were newly diagnosed with cancer from 2010 to 2016 and received national health screening before and after diagnosis were included and followed until 2019. Weight change status after cancer diagnosis was categorized into four groups: sustained normal weight, obese to normal weight, normal weight to obese, or sustained obese. Cox proportional hazard analyses were performed to examine associations between weight change and DM. Results: The study population comprised 264,250 cancer survivors. DM risk was highest in sustained obese (adjusted hazard ratios, 95% confidence interval: 2.17, 2.08-2.26), followed by normal weight to obese (1.66, 1.54-1.79), obese to normal weight (1.29, 1.21-1.39), and then sustained normal weight group (reference). In subgroup analyses according to cancer type, most cancers showed the highest risks in sustained obese group. Conclusion: Obesity at any time point was related to increased DM risk, presenting the highest risk in cancer survivors with sustained obesity. Survivors who changed from obese to normal weight had lower risk than survivors with sustained obesity. Survivors who changed from normal weight to obese showed increased risk compared to those who sustained normal weight. Our finding supports the significance of weight management among cancer survivors.

Functional Activities and Mechanisms of Aronia melanocarpa in Our Health.

Aronia melanocarpa, known as black chokeberry, is rich in polyphenols, comprising flavonoids, such as anthocyanins, flavanols, and flavonols, and phenolic acids, such as chlorogenic acid. These polyphenols endow Aronia melanocarpa with preventive and therapeutic properties against various human diseases. Aronia melanocarpa has beneficial effects against diseases such as diabetes, inflammation, and hypertension. Considering the diverse functional components of Aronia melanocarpa, its efficacy in disease prevention and treatment can operate through multiple pathways, offering a more robust approach to disease control. This review covers the latest research results on the functional components of Aronia melanocarpa and their effects on human diseases.

Disparities in Overall Survival Rates for Cancers across Income Levels in the Republic of Korea.

BACKGROUND: The overall survival rates among cancer patients have been improving. However, the increase in survival is not uniform across socioeconomic status. Thus, we investigated income disparities in the 5-year survival rate (5YSR) in cancer patients and the temporal trends. METHODS: This study used a national cancer cohort from 2002 to 2018 that was established by linking the Korea Central Cancer Registry and the National Health Insurance Service (NHIS) claim database to calculate the cancer survival rate by income level in the Republic of Korea. Survival data were available from 2002 onward, and the analysis was based on the actuarial method. We compared the survival of the earliest available 5-year period of 2002-2006 and the latest available 5-year period of 2014-2018, observing until 31 December 2021. Income level was classified into six categories: Medical Aid beneficiaries and five NHIS subtypes according to insurance premium. The slope index of inequality (SII) and relative index of inequality were used to measure absolute and relative differences in 5YSR by income, respectively. RESULTS: The 5YSR between the 2002-2006 and 2014-2018 periods for all cancers improved. A significant improvement in 5-year survival rates (5YSR) over the study period was observed in lung, liver, and stomach cancer. The SII of survival rates for lung (17.5, 95% confidence interval (CI) 7.0-28.1), liver (15.1, 95% CI 10.9-19.2), stomach (13.9, 95% CI 3.2-24.7), colorectal (11.4, 95% CI 0.9-22.0), and prostate (10.7, 95% CI 2.5-18.8) cancer was significantly higher, implying higher survival rates as income levels increased. The SII for lung, liver, and stomach cancer increased, while that of thyroid, breast, cervical, prostate, and colorectal cancer decreased over the study period. CONCLUSIONS: Although substantial improvement in the 5YSR was observed across cancer types and income levels from 2002 to 2018, this increase was not uniformly distributed across income levels. Our study revealed persistent income disparities in the survival of cancer patients, particularly for lung and liver cancer.

Low household income increases risks for chronic obstructive pulmonary disease in young population: a nationwide retrospective cohort study in South Korea.

BACKGROUND: Low socioeconomic status is a risk factor for chronic obstructive pulmonary disease (COPD); however, the association between low household income and COPD in young populations remains unclear. METHODS: We screened individuals aged 20-39 years who underwent the national health examination between 2009 and 2012 using the Korean National Health Information Database, which was searched until December 2019. We identified 5 965 366 eligible individuals, and 13 296 had newly developed COPD based on health insurance claims. We evaluated household income levels based on the health insurance premiums, categorised them into quartiles and 'Medical aid' (the lowest 3% income group), and assessed the annual income status from the preceding 4 years. Multivariate Cox proportional hazard models were used to estimate the adjusted HR (aHR) of risk factors for COPD. RESULTS: In the Medical aid group, the incidence rate for developing COPD was 0.56/1000 person-years, with an aHR of 2.45 (95% CI 1.91 to 3.13) compared with that of the highest income quartile group. This association was prominent in consecutive recipients of Medical aid (aHR 2.37, 95% CI 1.80 to 3.11) compared with those who had never been Medical aid beneficiaries. Those who experienced a decline in household income between the previous (preceding 4 years) and baseline time points had an increased risk of developing COPD, regardless of previous income status. CONCLUSION: Low household income was associated with an increased risk of developing COPD in the young population. This risk was augmented by sustained low income and declining income status.

Hair Growth Promoting Effects of 15-Hydroxyprostaglandin Dehydrogenase Inhibitor in Human Follicle Dermal Papilla Cells.

Prostaglandin E2 (PGE2) is known to be effective in regenerating tissues, and bimatoprost, an analog of PGF2α, has been approved by the FDA as an eyelash growth promoter and has been proven effective in human hair follicles. Thus, to enhance PGE2 levels while improving hair loss, we found dihydroisoquinolinone piperidinylcarboxy pyrazolopyridine (DPP), an inhibitor of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), using DeepZema®, an AI-based drug development program. Here, we investigated whether DPP improved hair loss in human follicle dermal papilla cells (HFDPCs) damaged by dihydrotestosterone (DHT), which causes hair loss. We found that DPP enhanced wound healing and the expression level of alkaline phosphatase in DHT-damaged HFDPCs. We observed that DPP significantly down-regulated the generation of reactive oxygen species caused by DHT. DPP recovered the mitochondrial membrane potential in DHT-damaged HFDPCs. We demonstrated that DPP significantly increased the phosphorylation levels of the AKT/ERK and activated Wnt signaling pathways in DHT-damaged HFDPCs. We also revealed that DPP significantly enhanced the size of the three-dimensional spheroid in DHT-damaged HFDPCs and increased hair growth in ex vivo human hair follicle organ culture. These data suggest that DPP exhibits beneficial effects on DHT-damaged HFDPCs and can be utilized as a promising agent for improving hair loss.

Increased cardiovascular disease risk among adolescents and young adults with gastric cancer.

BACKGROUND: Previous studies have investigated cardiovascular disease (CVD) risks in cancer patients, but there is limited knowledge concerning the CVD risk in adult and young adolescent (AYA) survivors of gastric cancer. OBJECTIVES: This study aims to investigate the incidence of CVD in AYA gastric cancer survivors, analyzing it by treatment type and identifying associated risk factors. METHODS: We conducted a retrospective cohort study using Korean National Health Insurance Service data collected from 2006 to 2019. Propensity score matching (1:3, caliper < 0.1) was performed using the variables age, sex, income, residential area, and presence of comorbidities, and we classified participants into gastric cancer (n = 6562) and non-cancer control (n = 19,678) groups. Cox regression models were used to calculate hazard ratios (HRs) for CVD incidence. The study assessed CVD incidence by cancer treatment and identified risk factors through multivariable Cox regression. RESULTS: During a median 6.5-year follow-up, AYA gastric cancer survivors consistently exhibited greater CVD incidence. Their risk of CVD was significantly elevated compared to that of controls (HR, 1.18; 95% confidence interval [CI] 1.05-1.33). In particular, deep vein thrombosis (HR, 3.93; 95% CI 3.06-14.67) and pulmonary embolism (HR, 6.58; 95% CI 3.06-14.67) risks were notably increased. Chemotherapy was associated with an increased risk of stroke, heart failure, atrial fibrillation, deep vein thrombosis, and pulmonary embolism. Hypertension (HR, 1.58; 95% CI 1.10-2.26) and dyslipidemia (HR, 1.46; 95% CI 1.06-2.20) emerged as risk factors for CVD development. CONCLUSION: This study reports elevated risks of CVD in AYA gastric cancer survivors and emphasizes the need for vigilant monitoring of CVD in this population.

Modifiable risk factors for weight loss after cancer treatment in Korean gastric cancer survivors.

PURPOSE: Weight loss is a critical problem in gastric cancer survivor (GCS) associated with worse prognosis and quality of life. Nevertheless, modifiable factors related to weight loss of GCS seem limited. We investigated the factors with significant weight loss including dietary pattern change in GCS. METHODS: In this cross-sectional study, Korean cancer survivors were recruited from two university-affiliated hospitals from 2014 to 2017. Overall, 591 GCSs were analyzed by preoperative body mass index levels. Significant and severe weight loss was defined as a weight reduction of more than 5% and 10%, respectively. RESULTS: Around 68.7% and 35.0% of GCS reported significant and severe weight loss, respectively. Age and surgery type were the important factors related to significant weight loss in total. In preoperative overweight or obese subjects, sex and surgery type were the risk factors for weight loss. Total food intake reduction was the only modifiable factor of significant weight loss (adjusted odds ratio (aOR) 1.78, 95% confidence interval (CI) 1.19-2.64), particularly in preoperative normal or underweight GCS (aOR 2.62, 95% CI 1.44-4.78). Increasing vegetable and salt reduction was found to be related to a lower risk of significant weight loss. The impact of reducing processed meat on weight loss differed by degree of weight loss and preoperative BMI level. CONCLUSIONS: Changing food consumption was the important modifiable factor related to significant weight loss which was more evident in preoperative underweight or normal GCS. Thus, further specific dietary recommendation is necessary for them to prevent significant weight loss. IMPLICATIONS FOR CANCER SURVIVORS: In order to prevent significant weight loss, dietary modification should be provided to GCS to ensure that total food intake does not decrease.

Disparities in the diagnosis and treatment of colorectal cancer among patients with disabilities.

BACKGROUND: Little is known about disparities in diagnosis and treatment among colorectal cancer (CRC) patients with and without disabilities. AIM: To investigate the patterns of diagnosis, treatment, and survival for people with and without disabilities who had CRC. METHODS: We performed a retrospective analysis using the Korean National Health Insurance Service database, disability registration data, and Korean Central Cancer Registry data. The analysis included 21449 patients with disabilities who were diagnosed with CRC and 86492 control patients diagnosed with CRC. RESULTS: The overall distribution of CRC stage was not affected by disability status. Subjects with disabilities were less likely than those without disabilities to undergo surgery [adjusted odds ratio (aOR): 0.85; 95% confidence interval (95%CI): 0.82-0.88], chemotherapy (aOR: 0.84; 95%CI: 0.81-0.87), or radiotherapy (aOR: 0.90; 95%CI: 0.84-0.95). The rate of no treatment was higher in patients with disabilities than in those without disabilities (aOR: 1.48; 95%CI: 1.41-1.55). The overall mortality rate was higher in patients with disabilities [adjusted hazard ratio (aHR): 1.24; 95%CI: 1.22-1.28], particularly severe disabilities (aHR: 1.57; 95%CI: 1.51-1.63), than in those without disabilities. CONCLUSION: Patients with severe disabilities tended to have a late or unknown diagnosis. Patients with CRC and disabilities had lower rates of treatment with almost all modalities compared with those without disabilities. During the follow-up period, the mortality rate was higher in patients with disabilities than in those without disabilities. The diagnosis and treatment of CRC need improvement in patients with disabilities.

Increased Risk of Fracture after Traumatic Amputation: A Nationwide Retrospective Cohort Study.

The physiological changes and alterations in gait following amputation may increase the risk of fractures. However, there is insufficient research on fracture risk in amputees. Therefore, this study intended to analyze whether the risk of new fractures increases after traumatic amputations. This population-based, retrospective cohort study used data from the Korean National Health Insurance System database. The study included 19,586 participants who had undergone an amputation and 76,645 matched controls. The incidence of any fracture and site-specific fractures (vertebral, hip, and others) according to amputation site(s) and severity of disability due to amputation were evaluated using Cox proportional hazard regression analysis. During the mean follow-up of 4.2 years, amputees had a higher incidence rate (IR) of any fracture (adjusted HR [aHR] 1.47, 95% CI 1.36-1.60), vertebral fracture (aHR 1.63, 95% CI 1.44-1.85), hip fracture (aHR 1.85, 95% CI 1.39-2.46), and other fracture (aHR 1.34, 95% CI 1.20-1.49) compared to that of controls. In the presence of disability, the risks were further increased and were highest among amputees with severe disabilities. All fracture risks were higher in amputees than they were in controls, regardless of lower limb or upper limb amputation. This cohort study demonstrated that traumatic amputees experienced higher incidence of all fractures than did individuals without amputations, and this risk increases with severity of disability. This finding underscores the importance of early screening and lifestyle interventions to address fracture risk in traumatic amputees.

Glycaemic Status and Risk of Abdominal Aortic Aneurysm: A Nationwide Cohort Study of Four Million Adults using Korean National Health Screening Data.

OBJECTIVE: This retrospective cohort study aimed to confirm the previously reported inverse association between diabetes mellitus (DM) and abdominal aortic aneurysm (AAA) using large population based data. It also investigated the associations between AAA and impaired fasting glucose (IFG) and new onset DM (not yet treated). METHODS: A representative dataset was obtained from the Korean National Health Insurance Service. Participants who were aged ≥ 50 years and received a national health examination in 2009 were included and followed until 31 December 2019. Glycaemic status was defined based on fasting plasma glucose level and the relevant diagnostic codes. AAA was ascertained using medical facility use records with relevant diagnostic codes or aneurysm repair surgery. A Cox proportional hazards model was used to examine the association between glycaemic status and AAA, with adjustment for confounders. Additionally, the interactions between glycaemic status and subgroups based on baseline characteristics were examined. RESULTS: The study population comprised 4 162 640 participants. Participants with IFG or DM were significantly more likely to be male, older, and have comorbidities compared with normoglycaemic participants at baseline. The incidence of AAA was lower in participants with IFG or DM compared with normoglycaemic participants. The AAA risk was lower in patients with DM than in patients with IFG, and decreased linearly according to glycaemic status: the adjusted hazard ratio was 0.88 (95% confidence interval [CI] 0.85 - 0.91) for IFG, 0.72 (95% CI 0.67 - 0.78) for newly diagnosed DM, 0.65 (95% CI 0.61 - 0.69) for DM duration < 5 years, and 0.47 (95% CI 0.44 - 0.51) for DM duration ≥ 5 years compared with the normoglycaemia group. Both IFG and DM were related to reduced AAA risk in all subgroups, suggesting an independent association. CONCLUSION: Both IFG and DM, even when not treated with antihyperglycaemic medication, were associated with a lower incidence of AAA. The AAA risk decreased linearly according to DM duration.

Migraine Risk in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder: A Nationwide Cohort Study in South Korea.

INTRODUCTION: Although the relationship between migraine and multiple sclerosis (MS) has been reported, the risk of migraine in MS and neuromyelitis optica spectrum disorder (NMOSD) is unclear. Therefore, this study investigated the risk of migraine in the Korean MS and NMOSD populations. METHODS: This study analyzed claims data from 1,492 patients with MS and 1,551 patients with NMOSD based on diagnostic codes in the Korean National Health Insurance Service. Migraine risk was compared with a control group (matched 1:5 for age, sex, and comorbidities) using Cox proportional hazards analysis. Patients aged <20 years and with previous migraine were excluded. RESULTS: Migraine risk was higher in patients with MS (adjusted hazard ratio [aHR] 1.37; 95% confidence interval [CI]: 1.15-1.62) but did not differ significantly in patients with NMOSD (aHR 1.05; 95% CI: 0.87-1.27) compared to controls. No significant sex-based differences in migraine risk were observed. Patients with NMOSD showed decreasing risk with age (p for interaction = 0.040). Comorbidities like hypertension, diabetes, or dyslipidemia did not significantly alter migraine risk in either group. CONCLUSION: The study results revealed an increased risk of migraines in patients with MS but not in patients with NMSOD compared with matched controls.

Exploring age-standardized cancer incidence rates and regional disparities: A retrospective cohort study of 8 major cancers in South Korea.

BACKGROUND: We analyzed trends in cancer incidence and regional disparities of eight major types of cancer in Korea. METHODS: This retrospective cohort study used the data of 17 cities/provinces from the Korea Central Cancer Registry (1999-2020) in South Korea. Age-standardized incidence rates (per 100,000 person-years), between-group variance (per 100,000 person-years)2, and annual percentage changes ( %) were calculated for the eight most common malignancies. Joinpoint regression was utilized to identify the points at which significant changes occur in cancer incidence or regional disparity trends over time to characterize these trends. RESULTS: The incidence of stomach cancer decreased as regional disparity decreased and that of colorectal cancer initially increased but recently declined, showing fluctuations in regional disparity. The incidence and regional disparity in liver cancer decreased. The incidence of lung cancer remained stable, with reduced regional disparities. The incidence of breast cancer rose with increasing regional disparity, whereas the incidence of cervical cancer decreased, accompanied by decreased regional disparity. A significant increase in prostate cancer was found, with initially reduced regional disparities but later showed a resurgence. The incidence of thyroid cancer fluctuated alongside variations in regional disparities. CONCLUSION: This study revealed cancer incidence and regional variations in each cancer type in Korea. More studies are needed to understand the underlying factors and potential interventions for reducing cancer incidence and addressing regional disparity.

Long-term health outcomes by cancer diagnosed age among adolescent and young adult: multinational representative database.

BACKGROUND: The cancer experienced in adolescent and young adult (AYA) could disturb developmental changes and long-term life. The current AYA guidelines and research for survivorship were developed and reported according to the general age range of 15-39 years; however, expected life events vary by diagnosed age. We aimed to examine the social, psychological, and physical well-being of AYA cancer survivors by age at diagnosis using a multinational representative dataset focusing on age at diagnosis. METHODS: We conducted a cross-sectional study using the US and Korean National Health and Nutrition Examination Surveys from 2007 to 2018. Participants diagnosed with any cancer aged 15-39 years and were aged > 18 years at the survey year were defined as AYA cancer survivors. AYA were classified into three groups based on their diagnosed age: adolescent survivors (diagnosed between the ages of 15 and 19, n = 45), young adult survivors (diagnosed between the ages of 20 and 29, n = 238), and late young adult survivors (diagnosed between the ages of 30 and 39, n = 539). We also selected an age-, sex-, race-, and survey year-matched general population with 1:5 ratio among participants without cancer (N = 4110). RESULTS: The average age of the survey was 29.1, 43.7, and 48.7 years for AYA survivors diagnosed during adolescence, young adulthood, and late young adulthood, respectively. Adolescent survivors had more non-couple marital status (adjusted odds ratio (aOR), 1.34; 95% CI, 1.10-1.64) and unemployed (aOR, 1.30; 95% CI, 1.05-1.61) compared to late young adult survivors. Comparing with the matched general, adolescent survivors were more in poor general health (aOR, 4.65; 95% CI, 2.09-10.38) and unemployed (aOR, 2.17; 95% CI, 1.12-4.24) and late young adult survivors were more non-couple (aOR, 1.40; 95% CI, 1.05-1.86). CONCLUSION: This study provides evidence for future studies on long-term health, which may vary according to age at the time of diagnosis among AYA with cancer.

Risk of Heart Disease in Patients With Amputation: A Nationwide Cohort Study in South Korea.

BACKGROUND: Amputation confers disabilities upon patients and is linked to substantial morbidity and death attributed to heart disease. While some studies have focused on traumatic amputees in veterans, few studies have focused on traumatic amputees within the general population. Therefore, the present study aimed to assess the risk of heart disease in patients with traumatic amputation with disability within the general population using a large-scale nationwide population-based cohort. METHODS AND RESULTS: We used data from the Korean National Health Insurance System. A total of 22 950 participants with amputation were selected with 1:3 age, sex-matched controls between 2010 and 2018. We used Cox proportional hazard models to calculate the risk of myocardial infarction, heart failure, and atrial fibrillation among amputees. Participants with amputation had a higher risk of myocardial infarction (adjusted hazard ratio [aHR], 1.30 [95% CI, 1.14-1.47]), heart failure (aHR, 1.27 [95% CI, 1.17-1.38]), and atrial fibrillation (aHR, 1.17 [95% CI, 1.03-1.33]). The risks of myocardial infarction and heart failure were further increased by the presence of disability (aHR, 1.43 [95% CI, 1.04-1.95]; and aHR, 1.38 [95% CI, 1.13-1.67], respectively). CONCLUSIONS: We demonstrate an increased risk of myocardial infarction, heart failure, and atrial fibrillation among individuals with amputation, and the risk further increased in those with disabilities. Clinicians should pay attention to the increased risk for heart disease in patients with amputation.

Association between physical activity changes and risk of incident ischemic stroke following cancer diagnosis: A nationwide retrospective cohort study.

BACKGROUND: Physical inactivity is prevalent after cancer treatment, which could increase ischemic stroke risk in cancer survivors. This study investigated the association between physical activity change from pre- to post-diagnosis and ischemic stroke risk among cancer survivors. METHODS: Using data from the Korean National Health Insurance Service database, 269,943 cancer survivors (mean [SD] age, 56.3 [12.1] years; 45.7% male) with no history of cardiovascular disease were evaluated based on changes in physical activity from pre- to post-diagnosis. Using the Fine-Gray model, subdistribution hazard ratios (sHRs) and 95% confidence intervals (CIs) for ischemic stroke risk were calculated, considering death as a competing risk. RESULTS: After cancer diagnosis, 62.0% remained inactive, 10.1% remained active, 16.6% became active, and 11.4% became inactive. During a mean (SD) follow-up of 4.1 (2.0) years, being active both pre- and post-diagnosis was associated with a 15% decreased risk of ischemic stroke (sHR, 0.85; 95% CI, 0.75-0.96), compared with those who remained inactive. Cancer survivors who became active and inactive post-diagnosis showed a 16% and 11% lower ischemic stroke risk (sHR, 0.84; 95% CI, 0.75-0.93; sHR, 0.89; 95% CI, 0.79-0.99), respectively, than those who remained inactive. Analysis by the primary cancer site did not substantially differ from the main findings. CONCLUSIONS: Physical activity is associated with reduced ischemic stroke risk among cancer survivors. The potential benefits of physical activity are not limited to individuals who were physically active before cancer diagnosis, thus preventive strategies against ischemic stroke should emphasize physical activity throughout the cancer journey.

A machine learning approach using conditional normalizing flow to address extreme class imbalance problems in personal health records.

BACKGROUND: Supervised machine learning models have been widely used to predict and get insight into diseases by classifying patients based on personal health records. However, a class imbalance is an obstacle that disrupts the training of the models. In this study, we aimed to address class imbalance with a conditional normalizing flow model, one of the deep-learning-based semi-supervised models for anomaly detection. It is the first introduction of the normalizing flow algorithm for tabular biomedical data. METHODS: We collected personal health records from South Korean citizens (n = 706), featuring genetic data obtained from direct-to-customer service (microarray chip), medical health check-ups, and lifestyle log data. Based on the health check-up data, six chronic diseases were labeled (obesity, diabetes, hypertriglyceridemia, dyslipidemia, liver dysfunction, and hypertension). After preprocessing, supervised classification models and semi-supervised anomaly detection models, including conditional normalizing flow, were evaluated for the classification of diabetes, which had extreme target imbalance (about 2%), based on AUROC and AUPRC. In addition, we evaluated their performance under the assumption of insufficient collection for patients with other chronic diseases by undersampling disease-affected samples. RESULTS: While LightGBM (the best-performing model among supervised classification models) showed AUPRC 0.16 and AUROC 0.82, conditional normalizing flow achieved AUPRC 0.34 and AUROC 0.83 during fifty evaluations of the classification of diabetes, whose base rate was very low, at 0.02. Moreover, conditional normalizing flow performed better than the supervised model under a few disease-affected data numbers for the other five chronic diseases - obesity, hypertriglyceridemia, dyslipidemia, liver dysfunction, and hypertension. For example, while LightGBM performed AUPRC 0.20 and AUROC 0.75, conditional normalizing flow showed AUPRC 0.30 and AUROC 0.74 when predicting obesity, while undersampling disease-affected samples (positive undersampling) lowered the base rate to 0.02. CONCLUSIONS: Our research suggests the utility of conditional normalizing flow, particularly when the available cases are limited, for predicting chronic diseases using personal health records. This approach offers an effective solution to deal with sparse data and extreme class imbalances commonly encountered in the biomedical context.