Impact of Polyethylene-Glycol-Induced Water Potential on Methane Yield and Microbial Consortium Dynamics in the Anaerobic Degradation of Glucose.

This study investigated the relationship between water potential (Ψ) and the cation-induced inhibition of methane production in anaerobic digesters. The Ψ around methanogens was manipulated using polyethylene glycol (PEG) in a batch anaerobic reactor, ranging from -0.92 to -5.10 MPa. The ultimate methane potential (Bu) decreased significantly from 0.293 to 0.002 Nm3 kg-1-VSadded as Ψ decreased. When Ψ lowered from -0.92 MPa to -1.48 MPa, the community distribution of acetoclastic Methanosarcina decreased from 59.62% to 40.44%, while those of hydrogenotrophic Methanoculleus and Methanobacterium increased from 17.70% and 1.30% to 36.30% and 18.07%, respectively. These results mirrored changes observed in methanogenic communities affected by cation inhibition with KCl. Our findings strongly indicate that the inhibitory effect of cations on methane production may stem more from the water stress induced by cations than from their direct toxic effects. This study highlights the importance of considering Ψ dynamics in understanding cation-mediated inhibition in anaerobic digesters, providing insights into optimizing microbial processes for enhanced methane production from organic substrates.

Stressful life events and serum triglyceride levels: the Cardiovascular and Metabolic Diseases Etiology Research Center cohort in Korea.

OBJECTIVES: Elevated serum triglyceride levels are a risk factor for developing cardiovascular disease. A number of studies have demonstrated a positive association between psychological stress and serum triglyceride levels. However, there is limited evidence regarding the impact of stressful life events (SLEs) on serum triglyceride levels in the healthy population. Therefore, we evaluated the independent association between SLEs and serum triglyceride levels in a middle-aged Korean population. METHODS: We analyzed a sample of 2,963 people (aged 30-64 years; 36% men) using baseline data from the Cardiovascular and Metabolic Diseases Etiology Research Center (CMERC) cohort study. The Korean version of the Life Experience Survey questionnaire was used to measure the presence and positive/negative impact of SLEs. Hypertriglyceridemia was defined as a fasting serum triglyceride level of ≥ 150 mg/dL. RESULTS: Of the 2,963 participants, 33.1% reported at least 1 SLE over the past 6 months and 24.8% had hypertriglyceridemia. Even after adjusting for potential confounders, the serum triglyceride level was significantly associated with the total number of SLEs in men (3.333 mg/dL per event; p= 0.001), but not in women (0.451 mg/dL per event, p= 0.338). Hypertriglyceridemia was also associated with having 4 or more SLEs with positive effects (odds ratio [OR], 2.57; 95% CI, 1.02 to 6.46) and 4 or more SLEs with negative effects (OR, 1.99; 95% CI, 1.16 to 3.41) in men. CONCLUSIONS: Our findings suggest that SLEs may increase the risk of hypertriglyceridemia in middle-aged men.

Annual incidence and prevalence of obesity in childhood and young adulthood based on a 30-year longitudinal population-based cohort study in Korea: the Kangwha study.

PURPOSE: Childhood obesity is a major global issue that causes a variety of health problems and high social costs. Many previous studies have investigated childhood obesity using cross-sectional data, but few longitudinal cohort studies have been performed, especially in the Korean population. METHODS: We analyzed the incidence and prevalence of obesity and overweight in a Korean prospective cohort study of children that were followed-up from age 7 to age 36. The study eventually recruited a total of 1216 participants, with 16 follow-up surveys over 30 years (1986-2017). RESULTS: The annual incidence of obesity showed a small peak (2.1%) at age 13 when the cohort entered middle school, but a rapid increase (6.4%) when participants reached the age of 20. The prevalence of obesity and overweight at age 8 was 0.8% and 0.9%, respectively, and increased rapidly from age 12 (obesity 2.2%, overweight 4.6%), reaching 9.5% and 15.9%, respectively, at age 20. The prevalence of obesity and overweight was consistently higher in girls than in boys during the childhood period, but this trend reversed in adulthood. CONCLUSIONS: Incidence and prevalence of obesity and overweight increased markedly after the final grades of elementary school in females, but after adolescence in males.

Effect of Smartphone-Based Lifestyle Coaching App on Community-Dwelling Population With Moderate Metabolic Abnormalities: Randomized Controlled Trial.

BACKGROUND: Metabolic disorders are established precursors to cardiovascular diseases, yet they can be readily prevented with sustained lifestyle modifications. OBJECTIVE: We assessed the effectiveness of a smartphone-based weight management app on metabolic parameters in adults at high-risk, yet without physician diagnosis nor pharmacological treatment for metabolic syndrome, in a community setting. METHODS: In this 3-arm parallel-group, single-blind, randomized controlled trial, we recruited participants aged 30 to 59 years with at least 2 conditions defined by the Third Report of the National Cholesterol Education Program expert panel (abdominal obesity, high blood pressure, high triglycerides, low high-density lipoprotein cholesterol, and high fasting glucose level). Participants were randomly assigned (1:1:1) by block randomization to either the nonuser group (control), the app-based diet and exercise self-logging group (app only), or the app-based self-logging and personalized coaching from professional dieticians and exercise coordinators group (app with personalized coaching). Assessments were performed at baseline, week 6, week 12, and week 24. The primary outcome was change in systolic blood pressure (between baseline and follow-up assessments). Secondary outcomes were changes in diastolic blood pressure, body weight, body fat mass, waist circumference, homeostatic model of assessment of insulin resistance, triglyceride level, and high-density lipoprotein cholesterol level between baseline and follow-up assessments. Analysis was performed using intention-to-treat. RESULTS: Between October 28, 2017 and May 28, 2018, 160 participants participated in the baseline screening examination. Participants (129/160, 80.6%) who satisfied the eligibility criteria were assigned to control (n=41), app only (n=45), or app with personalized coaching (n=43) group. In each group, systolic blood pressure showed decreasing trends from baseline (control: mean -10.95, SD 2.09 mmHg; app only: mean -7.29, SD 1.83 mmHg; app with personalized coaching: mean -7.19, SD 1.66 mmHg), yet without significant difference among the groups (app only: P=.19; app with personalized coaching: P=.16). Instead, those in the app with personalized coaching group had greater body weight reductions (control: mean -0.12, SD 0.30 kg; app only: mean -0.35, SD 0.36 kg, P=.67; app with personalized coaching: mean -0.96, SD 0.37 kg; P=.08), specifically by body fat mass reduction (control: mean -0.13, SD 0.34 kg; app only: mean -0.64, SD 0.38 kg, P=.22; app with personalized coaching: mean -0.79, SD 0.38 kg; P=.08). CONCLUSIONS: Simultaneous diet and exercise self-logging and persistent lifestyle modification coaching were ineffective in lowering systolic blood pressure but effective in losing weight and reducing body fat mass. These results warrant future implementation studies of similar models of care on a broader scale in the context of primary prevention. TRIAL REGISTRATION: ClinicalTrials.gov NCT03300271; http://clinicaltrials.gov/ct2/show/NCT03300271.

Factors Associated with Awareness, Treatment, and Control Rate of Hypertension among Korean Young Adults Aged 30-49 Years.

BACKGROUND AND OBJECTIVES: Hypertension awareness, treatment, and control have been substantially improved in the last decades worldwide, but hypertension management in younger adults is still challenged. We analyzed a nationally representative sample of Korea to investigate factors affecting hypertension management among the young Korean population. METHODS: Among 8,024 young adults aged 30-49 years from the 2014-2018 Korea National Health and Nutrition Examination Survey, 1,103 participants with hypertension were analyzed to identify factors associated with hypertension management status. Multiple logistic regression models were conducted separately by sex. RESULTS: Young adults with hypertension showed a low rate of awareness (35.8%), treatment (30.9%), and control (23.0%). The older age (40-49 years), obese (body mass index ≥25.0 kg/m²), having diabetes mellitus (DM), and having past-history of cardiovascular disease were positively associated with awareness, and taking health examination in the past 2 years were positively associated with both treatment and control of hypertension among male. Young females who were older (40-49 years), rural residents, unemployed, not taking sodium over the recommended amount, having dyslipidemia, and having DM showed a higher likelihood of awareness. Young females who have not experienced unmet medical needs in the past year were more likely to be treated or controlled with hypertension. CONCLUSIONS: The factors associated with hypertension awareness, treatment, and control were different by sex and age group. Enhancing attention on hypertension among young hypertension and encouraging them to visit clinics would be key strategies to improve hypertension management among the young hypertensive population.

Comparison of Computed Tomography-based Abdominal Adiposity Indexes as Predictors of Non-alcoholic Fatty Liver Disease Among Middle-aged Korean Men and Women.

OBJECTIVES: We compared the associations of 3 computed tomography (CT)-based abdominal adiposity indexes with non-alcoholic fatty liver disease (NAFLD) among middle-aged Korean men and women. METHODS: The participants were 1366 men and 2480 women community-dwellers aged 30-64 years. Three abdominal adiposity indexes-visceral fat area (VFA), subcutaneous fat area (SFA), and visceral-to-subcutaneous fat ratio (VSR)-were calculated from abdominal CT scans. NAFLD was determined by calculating the Liver Fat Score from comorbidities and blood tests. An NAFLD prediction model that included waist circumference (WC) as a measure of abdominal adiposity was designated as the base model, to which VFA, SFA, and VSR were added in turn. The area under the receiver operating characteristic curve (AUC), integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were calculated to quantify the additional predictive value of VFA, SFA, and VSR relative to WC. RESULTS: VFA and VSR were positively associated with NAFLD in both genders. SFA was not significantly associated with NAFLD in men, but it was negatively associated in women. When VFA, SFA, and VSR were added to the WC-based NAFLD prediction model, the AUC improved by 0.013 (p<0.001), 0.001 (p=0.434), and 0.009 (p=0.007) in men and by 0.044 (p<0.001), 0.017 (p<0.001), and 0.046 (p<0.001) in women, respectively. The IDI and NRI were increased the most by VFA in men and VSR in women. CONCLUSIONS: Using CT-based abdominal adiposity indexes in addition to WC may improve the detection of NAFLD. The best predictive indicators were VFA in men and VSR in women.

Protection of Healthcare Workers Against COVID-19 at a Large Teaching Hospital in Seoul, Korea.

Thirteen patients with coronavirus disease 2019 (COVID-19) visited a university hospital in Seoul before recognizing their disease infections, causing contact with 184 hospital workers. We classified the patients into four risk levels and provided corresponding management measures. At 31 days after the last event, all screening laboratory results were negative, and no symptoms/signs were reported.

Cost-effectiveness of para-aortic lymphadenectomy before chemoradiotherapy in locally advanced cervical cancer.

OBJECTIVE: To evaluate the cost-effectiveness of nodal staging surgery before chemoradiotherapy (CRT) for locally advanced cervical cancer in the era of positron emission tomography/computed tomography (PET/CT). METHODS: A modified Markov model was constructed to evaluate the cost-effectiveness of para-aortic staging surgery before definite CRT when no uptake is recorded in the para-aortic lymph nodes (PALN) on PET/CT. Survival and complication rates were estimated based on the published literature. Cost data were obtained from the Korean Health Insurance Review and Assessment Service. Strategies were compared using an incremental cost-effectiveness ratio (ICER). Sensitivity analyses were performed, including estimates for the performance of PET/CT, postoperative complication rate, and varying survival rates according to the radiation field. RESULTS: We compared two strategies: strategy 1, pelvic CRT for all patients; and strategy 2, nodal staging surgery followed by extended-field CRT when PALN metastasis was found and pelvic CRT otherwise. The ICER for strategy 2 compared to strategy 1 was $19,505 per quality-adjusted life year (QALY). Under deterministic sensitivity analyses, the model was relatively sensitive to survival reduction in patients who undergo pelvic CRT alone despite having occult PALN metastasis. A probabilistic sensitivity analysis demonstrated the robustness of the case results, with a 91% probability of cost-effectiveness at the willingness-to-pay thresholds of $60,000/QALY. CONCLUSION: Nodal staging surgery before definite CRT may be cost-effective when PET/CT imaging shows no evidence of PALN metastasis. Prospective trials are warranted to transfer these results to guidelines.

The cost-effectiveness of selective lymphadenectomy based on a preoperative prediction model in patients with endometrial cancer: insights from the US and Korean healthcare systems.

OBJECTIVE: The aim of this study was to determine the cost-effectiveness of selective lymphadenectomy using a preoperative prediction model compared to routine lymphadenectomy for patients undergoing surgery for endometrial cancer in the US and Korea. METHODS: We used a modified Markov model to estimate clinical and economic outcomes for newly diagnosed, apparent early-stage endometrial cancer patients under two different strategies: (1) selective lymphadenectomy, where patients classified as low risk based on the preoperative prediction model did not undergo complete surgical staging, and (2) routine lymphadenectomy, where all patients underwent complete surgical staging. Published data were used to estimate the rates of adjuvant therapy and survival. Costs were calculated from the perspective of US or Korean payers. Cost-effectiveness ratios were analyzed separately using data from each country. RESULTS: Base-case analysis indicated that selective lymphadenectomy was less costly ($6454 vs. $7079 in Korea; $23,995 vs. $26,318 in the US) and more effective (6.91 quality-adjusted life years (QALYs) vs. 6.85 QALYs in Korea; 6.87 QALYs vs. 6.81 QALYs in the US) than routine lymphadenectomy in both countries. This result was robust in a deterministic sensitivity analysis, with the exception of when the utility scores for patients with lymphedema were varied. So long as a modest preference for avoiding lymphedema (disutility of 0.04) was obtained, selective lymphadenectomy remained the dominant strategy. CONCLUSIONS: A selective lymphadenectomy strategy based on a preoperative prediction model was shown to be more cost-effective than routine lymphadenectomy for endometrial cancer patients in the US and Korea.