Although the biological mechanisms underlying the beneficial effects of vitamin B₆ on cardiovascular disease (CVD) have been reported on, epidemiological studies have yielded controversial results, and data on the Korean population are limited. This study examined the association between dietary vitamin B₆ intake and CVD incidence in Koreans. A total of 9142 participants of the Korean Genome and Epidemiology Study, aged 40–69 years, who did not have CVD or cancer at the baseline were included in the analysis. Dietary data were assessed using a validated semi-quantitative food frequency questionnaire. CVD incidence was assessed using biennial questionnaires and confirmed through repeated personal interviews. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazard regression models. After multivariate adjustment, a higher vitamin B₆ intake was significantly associated with a decreased CVD risk in men (HR: 0.44; 95% CI: 0.25–0.78); no such association was observed in women. Dose-response analysis confirmed the presence of inverse linearity between vitamin B₆ intake and CVD incidence in men (p for nonlinearity = 0.3). A higher dietary intake level of vitamin B₆ was associated with a reduced CVD risk in Korean men. These observations require further verification in other populations.

Objective: To evaluate whether patients with epilepsy were more susceptible to coronavirus disease 2019 (COVID-19) infection and at greater risk of severe complications when infected with COVID-19 when compared with patients without epilepsy. Methods: We included participants who underwent at least one SARS-CoV-2 real-time reverse transcription polymerase chain reaction test between Jan 1 and June 4, 2020 from the Korean nationwide COVID-19 dataset. Epilepsy was defined according to the presence of diagnostic code in health claims data prior to the COVID-19 diagnosis. To investigate the association between epilepsy and the susceptibility or severe complications of COVID-19, a 1:6 ratio propensity score matching (PSM) and logistic regression analysis were performed. Severe complications with COVID-19 infection were defined as a composite of the incidence of mechanical ventilation, intensive care unit admission, and death within two months after COVID-19 diagnosis. Results: Among 212,678 study participants who underwent COVID-19 test, 3,919 (1.8%) had a history of epilepsy. After PSM, there was no significant difference in COVID-19 PCR positivity according to epilepsy history [odds ratio (OR): 0.86, 95% confidence interval (CI) 0.67–1.11]. Of the 7,713 individuals with confirmed COVID-19 infection, 72 (0.9%) had a history of epilepsy. Among the COVID-19 patients, the severe complications occurred in 444 (5.8%) individuals. After PSM, the presence of epilepsy was associated with occurrence of severe complications after COVID-19 infection [OR: 2.05, 95% CI: 1.04–4.04]. Mortality following COVID-19 infection did not differ according to the presence of epilepsy history [OR: 1.55, 95% CI: 0.65–3.70]. Conclusions: The presence of epilepsy was not associated with increased susceptibility to COVID-19 infection or mortality related to the infection. However, there was an increased risk of severe complications with COVID-19 in patients with epilepsy; therefore, careful management and monitoring may be necessary.

The effect of calcium consumption in the prevention of type 2 diabetes mellitus (T2DM) remains controversial, and depends on food calcium sources. This prospective study aimed to evaluate the association between calcium-rich food consumption and T2DM incidence among Korean adults. We analyzed the data of 8574 adults aged 40–69 years, without a history of T2DM, cardiovascular disease, and cancer at the baseline from the Korean Genome and Epidemiology Study. The consumption of calcium-rich foods was assessed using a validated semi-quantitative food frequency questionnaire. T2DM-related data were collected using biennial questionnaires, health examinations, and clinical tests. Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using Cox proportional hazards regression models. In the multivariate-adjusted model, yogurt intake was inversely associated with T2DM risk (HR: 0.73; 95% CI: 0.61–0.88 in the fourth quartile as compared to the first quartile). However, the intakes of other calcium-rich foods, including milk and anchovies, were not significantly associated with T2DM risk. Yogurt may provide protective effects against T2DM in Korean adults, owing to the beneficial effects of probiotics. Further prospective large-scale cohort studies should be conducted to validate these findings.

Oral diseases, such as periodontitis and dental caries, can cause systemic inflammation as well as local effects, which is an important contributing factor for obesity. We aimed to investigate the change in body mass index (BMI) according to the presence of periodontitis and oral hygiene indicators. This study enrolled 110,068 participants from the national health screening cohort in Korea from 2009–2010 who underwent an oral health checkup. As oral hygiene indicators, the presence of periodontitis, dental caries, tooth loss, and tooth brushing were assessed. We constructed a linear mixed model for BMI. BMI was repeatedly measured in the health examination until 2015. In the multivariate linear mixed model for BMI, the presence of periodontitis (β = 0.0687, standard error (SE) = 0.0225, p = 0.002), dental caries (β = 0.0735, SE = 0.0152, p < 0.001), and tooth loss (β = 0.1328, SE = 0.0175, p < 0.001) were positively associated with BMI. In contrast, frequent tooth brushing (≥3 times/day) was negatively associated with BMI (β = −0.2610, SE = 0.0306, p < 0.001). The presence of periodontitis, dental caries, and tooth loss may be associated with higher BMI, whereas frequent tooth brushing may be related to lower BMI. Better oral hygiene might be associated with lower BMI. Further study is needed to determine the effect of oral health behavior and dental disease on obesity.

Infection is associated with the occurrence, recurrence, and progression of atrial fibrillation (AF), and is also closely related to poor prognosis. However, studies of the relationship between infectivity and severe complications of coronavirus infectious disease‐19 (COVID‐19) with a history of AF are limited. To estimate infectivity and severity of complications in COVID‐19 patients with a history of AF, this study was done. From the Korean nationwide COVID‐19 dataset, 212 678 participants with at least one severe acute respiratory syndrome coronavirus 2 (COVID‐19) test were included between January 1 and June 4, 2020. AF was defined according to at least two outpatient hospital visits or one admission with an ICD‐10 code of “I48” before the COVID‐19 test. To investigate the association of AF with infectivity and severe complications of COVID‐19, 1:4 ratio propensity score matching (PSM) was performed. Severe complications of COVID‐19 were defined as a composite outcome of mechanical ventilation, intensive care unit admission, and death within 2 months after COVID‐19 diagnosis. Among 212 678 participants who underwent the COVID‐19 test, there were 7713 COVID‐19 positive patients. After PSM, COVID‐19 PCR positivity did not show a significant difference according to the presence of AF (odds ratio [OR]: 0.79, 95% confidence interval [CI]: [0.60–1.04]). Of 7713 COVID‐19 patients, 62 (0.8%) had a history of AF and severe complications occurred in 444 (5.7%) patients. After PSM, AF was associated with the development of severe complications (OR: 2.04, 95% CI: [1.10–3.79]) and mortality (OR: 2.09, 95% CI: [1.01–4.31]) of COVID‐19. We found that AF was associated with an increased risk of severe complications in COVID‐19 infected patients.