Longitudinal trends in direct costs and healthcare utilization ascribable to inflammatory bowel disease in the biologic era: a nationwide, population-based study.

BACKGROUND AND AIM: Biologic-era data regarding the direct cost and healthcare utilization of inflammatory bowel disease at the population level are limited, especially in Asia. Thus, we aimed to investigate the nationwide prevalence, direct cost, and healthcare utilization of inflammatory bowel disease in Korea in a recent 10-year period. METHODS: Using the Korean National Health Insurance claim data from 2008 to 2017, we investigated all prescription medications and their associated direct costs, hospitalizations, and outpatient visits. We also estimated the nationwide prevalence of inflammatory bowel disease using population census data. RESULTS: The estimated inflammatory bowel disease prevalence significantly increased from 108.8/100 000 in 2008 to 140.4/100 000 in 2017. The overall annual costs for inflammatory bowel disease and the healthcare cost per capita increased from $24.5 million (in US dollars) to $105.1 million and from $458.4 to $1456.6 million, respectively (both P < 0.001). Whereas the ratio of outpatient costs increased from 35.3% to 69.4%, that of outpatient days remained steady. The total annual medication cost and proportion rose from $13.3 million to $76.8 million and from 54.2% to 73.3%, respectively, mainly due to the increasing antitumor necrosis factor cost, from $1.5 million to $49.3 million (from 11.1% to 64.1% of the total annual drug cost and from 6.3% to 46.9% of the total annual cost). CONCLUSIONS: We observed increasing trends in the prevalence, direct costs, and healthcare utilization of inflammatory bowel disease in Korea in recent years. The attributable cost was mainly driven by rising expenditures on antitumor necrosis factor medications.

Expression and prognostic significance of Niemann-Pick C1-Like 1 in colorectal cancer: a retrospective cohort study.

BACKGROUND: Colorectal cancer (CRC) is a malignancy of the large intestine, whose development and prognosis have been demonstrated to be associated with altered lipid metabolism. High cholesterol intake is associated with an increased risk of CRC, and elevated serum cholesterol levels are known to be correlated with risk of developing CRC. Niemann-Pick C1-Like 1 (NPC1L1), a target of ezetimibe, plays an essential role in the absorption of intestinal cholesterol. However, whether the altered expression of NPC1L1 affects CRC development and prognosis is currently unknown. METHODS: Data corresponding to patients with CRC were obtained from The Cancer Genome Atlas (TCAG). Datasets from the Genome Data Analysis Center (GDAC) platform were analyzed to compare the expression of NPC1L1 in normal and CRC tissues using the Mann-Whitney U test and chi-square test. Further, the datasets from the Gene Expression Omnibus (GEO) database were analyzed. The log-rank test and multivariate Cox proportional hazard regression analysis were performed to determine whether NPC1L1 significantly affects the prognosis of CRC. RESULTS: The expression of NPC1L1 was found to be upregulated in CRC and was significantly associated with the N and pathological stages but not with the histological type, age, and sex. Increased NPC1L1 expression in CRC was related to poor patient survival, as evidenced by the Kaplan-Meier and multivariate regression analyses. CONCLUSIONS: As high expression of NPC1L1 was associated with CRC development, pathological stage, and prognosis, NPC1L1 can serve as an independent prognostic marker for CRC.

Uncovering multiloci-ordering by algebraic property of Laplacian matrix and its Fiedler vector.

MOTIVATION: The loci-ordering, based on two-point recombination fractions for a pair of loci, is the most important step in constructing a reliable and fine genetic map. RESULTS: Using the concept from complex graph theory, here we propose a Laplacian ordering approach which uncovers the loci-ordering of multiloci simultaneously. The algebraic property for a Fiedler vector of a Laplacian matrix, constructed from the recombination fraction of the loci-ordering for 26 loci of barley chromosome IV, 846 loci of Arabidopsis thaliana and 1903 loci of Malus domestica, together with the variable threshold uncovers their loci-orders. It offers an alternative yet robust approach for ordering multiloci. AVAILABILITY AND IMPLEMENTATION: Source code program with data set is available as supplementary data and also in a software category of the website (http://biophysics.dgist.ac.kr) CONTACT: crkim@pusan.ac.kr or iksoochang@dgist.ac.kr SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Effect of sensor location on regional cerebral oxygen saturation measured by INVOS 5100 in on-pump cardiac surgery.

PURPOSE: Near-infrared spectroscopy sensors often cannot be attached at the commercially recommended locations because combined use of neurological monitoring systems is common during on-pump cardiac surgery. The primary purpose of this study was to compare the incidence of regional cerebral oxygen desaturation and regional cerebral oxygen saturation values detected using near-infrared spectroscopy between the upper and lower forehead during on-pump cardiac surgery. METHODS: A prospective observational study was conducted with 25 adult patients scheduled for elective on-pump cardiac surgery. Regional cerebral oxygen saturations at the left upper and lower forehead and other clinical measurements were monitored intraoperatively. McNemar's test was used to analyze differences in the incidence of cerebral regional oxygen desaturation between the left upper and lower forehead. Two-way repeated measures ANOVA with post hoc Bonferroni correction was used to compare the regional cerebral oxygen saturation at each time point. RESULTS: There was a significantly higher incidence of regional cerebral oxygen desaturation at the upper than lower forehead only at 1 h after initiation of aortic cross-clamping. There were significant differences between the left upper and lower regional cerebral oxygen saturation values throughout the observation period. CONCLUSION: Regional cerebral oxygen saturation was significantly lower at the upper than lower forehead during on-pump cardiac surgery. However, disagreements in detection of cerebral regional oxygen desaturation were only significant at 1 h after initiation of aortic cross-clamping. TRIAL REGISTRATION: WHO-ICTRP, Clinical Research Information Service (CRiS). ID: KCT0000971. URL: https://cris.nih.go.kr/cris/search/search_result_st01_en.jsp?seq=3678&type=my .

Vitamin D receptor gene polymorphisms and type 1 diabetes mellitus in a Korean population.

BACKGROUND: Vitamin D receptor (VDR) has been suggested to play a role in the pathogenesis of type 1 diabetes mellitus (T1DM). There has been no case-control study examining the association between VDR polymorphisms and T1DM among Korean subjects with a low incidence of T1DM. METHODS: Eighty-one T1DM patients and 113 unrelated healthy controls with no history of DM or other autoimmune diseases were investigated at either Pusan National University Children's Hospital or Korea University Anam Hospital between March 2009 and September 2013. Polymerase chain reaction-restriction fragment length polymorphism was utilized to genotype single nucleotide substitutions at TaqI, BsmI, and ApaI alleles. RESULTS: All frequencies in T1DM and control subjects were in Hardy-Weinberg equilibrium, although ApaI in controls and TaqI in T1DM showed relatively weak equilibrium. TaqI and BsmI differences were significant (P = 0.045 and P = 0.012, respectively) after applying Bonferroni correction. The TT genotype carrier frequency among controls was higher than among the T1DM patients (P = 0.015; OR, 2.98; 95%CI: 1.19-7.42). T allele frequency was higher among controls than T1DM patients (P = 0.019; OR, 2.78; 95%CI: 1.15-6.72). The frequency of bb genotype carriers among controls was higher than among T1DM patients (P = 0.004; OR, 4.13; 95%CI: 1.4-12.10). The frequency of the b allele among controls was higher than that among T1DM patients (P = 0.016; OR, 3.20; 95%CI: 1.19-8.60). CONCLUSIONS: T and b TaqI and BsmI alleles are protective against T1DM in Korean subjects.

The effects of anesthetics on chronic pain after breast cancer surgery.

BACKGROUND: The incidence and predictive factors for chronic pain after breast cancer surgery have been widely studied. Because it negatively affects patients' daily lives, methods to prevent and reduce chronic pain and its severity should be developed. Our previous study showed that propofol anesthesia has an antihyperalgesic effect under remifentanil-induced hyperalgesia and reduced acute pain compared with sevoflurane anesthesia. In this study, we investigated the hypothesis that propofol would prevent the development and severity of chronic pain after breast cancer surgery, as in acute pain. METHODS: A retrospective study was conducted with 175 women (n = 86 in the propofol group and n = 89 in the sevoflurane group) aged 20 to 65 years who underwent breast cancer surgery between March 2007 and December 2008. Patients were followed up by telephone in July 2011. Analysis included incidence, severity, and duration of chronic pain between propofol and sevoflurane groups. Severity was categorized into mild, moderate, and severe pain. Duration of chronic pain was also divided into 3 categories by 1-year time interval. Risk factors associated with the incidence and severity of chronic pain after breast cancer surgery were also identified. RESULTS: Chronic pain after breast cancer surgery was more likely to occur in the sevoflurane group compared with the propofol group (95% confidence interval [CI] 1.146-1.809, P = 0.007). Among patients with chronic pain, neither the severity (95% CI 0.516-7.419) nor duration (95% CI 0.106-1.007) differed between patients receiving sevoflurane and propofol. Younger age (95% CI 0.907-0.992, P = 0.021), axillary lymph node dissection (95% CI 1.204-1.898, P = 0.003), 24-hour postoperative morphine consumption (95% CI 1.004-1.116, P = 0.036), and sevoflurane (95% CI 1.146-1.809, P = 0.007) were predictive factors for the development of chronic pain. Higher 24-hour postoperative morphine consumption (95% CI 1.001-1.379, P = 0.049) increased the severity of chronic pain. CONCLUSIONS: This study showed that propofol anesthesia was associated with a lower incidence of chronic pain after breast cancer surgery than sevoflurane anesthesia. However, propofol did not have a significant effect on severity and duration of chronic pain. Further prospective studies are needed to confirm the validity of these provocative findings.

Predictive Power of the Albumin-Bilirubin Score for Hepatotoxicity in Stereotactic Ablative Radiation Therapy for Hepatocellular Carcinoma.

Assessment of liver function is crucial in predicting treatment outcomes for hepatocellular carcinoma (HCC). This study aimed to evaluate the prognostic performance of the albumin-bilirubin (ALBI) score for predicting hepatotoxicity following stereotactic body radiation therapy (SBRT) in HCC patients. A retrospective analysis was conducted on 123 HCC cases treated between 2018 and 2020. ALBI and Child-Turcotte-Pugh (CTP) scores were calculated, and hepatotoxicity was defined as a post-SBRT CTP score increase ≥2. Receiver operating characteristic (ROC) curves were used for comparison. The optimal cutoff value of the ALBI score was determined. Among the 121 patients analyzed, hepatotoxicity occurred in 5%. The ALBI score showed better predictive accuracy (area under the ROC curve: 0.77) than the CTP score. The optimal cutoff value of the ALBI score was -2.47, with a sensitivity of 85.7% and a specificity of 71.1%. Multivariable analysis revealed that ALBI score and PTV were significant factors for hepatotoxicity. In conclusion, the ALBI score demonstrated prognostic value for hepatotoxicity prediction after SBRT in HCC patients. Considering the ALBI score and PTV provides valuable insights for assessing hepatotoxicity risk during SBRT treatment for HCC.

Incidence of hypothyroidism after treatment for breast cancer: A Korean population-based study.

This Korean population-based study aimed to describe the patterns of hypothyroidism after adjuvant radiation therapy (RT) in patients with breast cancer. The Korean Health Insurance Review and Assessment Service database was searched for patients with invasive breast carcinomas. We calculated the cumulative incidence and incidence rates per 1,000 person-years of subsequent hypothyroidism and compared them using the log-rank test and the Cox proportional hazards model. Between 2007 and 2018, 117,135 women diagnosed with breast cancer with a median follow-up time of 4.6 years were identified. The 8-year incidence of hypothyroidism was 9.3% in patients treated with radiation and 8.6% in those treated without radiation (p = 0.002). The incidence rates per 1,000 person-years in the corresponding treatment groups were 6.2 and 5.7 cases, respectively. The hazard ratio (HR) in patients receiving RT was 1.081 (95% confidence interval [CI], 1.013-1.134; p = 0.002). After mastectomy, RT showed a trend toward a higher risk of hypothyroidism (HR = 1.248; 95% CI, 0.977-1.595; p = 0.076). Our study provides one of the largest population-based data analyses regarding the risk of hypothyroidism among Korean patients with breast cancer. The adjusted risk for patients treated with RT exceeded that for patients with breast cancer treated without RT. The effect was evident immediately after treatment and lasted up to approximately 9 years.

A simple and exact Laplacian clustering of complex networking phenomena: application to gene expression profiles.

Unraveling of the unified networking characteristics of complex networking phenomena is of great interest yet a formidable task. There is currently no simple strategy with a rigorous framework. Using an analogy to the exact algebraic property for a transition matrix of a master equation in statistical physics, we propose a method based on a Laplacian matrix for the discovery and prediction of new classes in the unsupervised complex networking phenomena where the class of each sample is completely unknown. Using this proposed Laplacian approach, we can simultaneously discover different classes and determine the identity of each class. Through an illustrative test of the Laplacian approach applied to real datasets of gene expression profiles, leukemia data [Golub TR, et al. (1999) Science 286:531-537], and lymphoma data [Alizadeh AA, et al. (2000) Nature 403:503-511], we demonstrate that this approach is accurate and robust with a mathematical and physical realization. It offers a general framework for characterizing any kind of complex networking phenomenon in broad areas irrespective of whether they are supervised or unsupervised.

A prospective cohort study on emergence of permanent teeth and caries experience in Korean children.

OBJECTIVES: The objectives of this study were to investigate permanent tooth emergence during a 9-year longitudinal study and to assess the effect of dental caries in primary teeth on the emergence of permanent teeth. METHODS: Data on caries occurrence in primary teeth were obtained at the baseline by a trained dentist. Permanent tooth emergence data of 539 students from 16 elementary schools in Yeoncheon were examined annually from 1995 to 2003 using dental casts. The median age at emergence of the teeth was calculated using a linear logistic regression model. A multiple linear regression model was used to evaluate the effect of caries on the emergence of permanent teeth. RESULTS: The age of permanent tooth emergence was different between boys and girls, but the difference was not statistically significant at the 5% level. Having 'decayed teeth' hastened the emergence of most second premolars and second molars, whereas the regression coefficients ranged from -1.23 to -0.82. The number of 'filled teeth' showed a correlation with maxillary second premolars and mandibular first premolar, and the regression coefficients ranged from -1.92 to -3.25. CONCLUSIONS: Having dental caries in primary teeth can be a strong predictor of earlier emergence of permanent teeth.

Impact of COVID-19 on Emergency Medical Services for Patients with Acute Stroke Presentation in Busan, South Korea.

The purpose of this retrospective observational study was to identify the impact of COVID-19 on emergency medical services (EMS) processing times and transfers to the emergency department (ED) among patients with acute stroke symptoms before and during the COVID-19 pandemic in Busan, South Korea. The total number of patients using EMS for acute stroke symptoms decreased by 8.2% from 1570 in the pre-COVID-19 period to 1441 during the COVID-19 period. The median (interquartile range) EMS processing time was 29.0 (23-37) min in the pre-COVID-19 period and 33.0 (25-41) minutes in the COVID-19 period (p < 0.001). There was a significant decrease in the number of patients transferred to an ED with a comprehensive stroke center (CSC) (6.37%, p < 0.001) and an increase in the number of patients transferred to two EDs nearby (2.77%, p = 0.018; 3.22%, p < 0.001). During the COVID-19 pandemic, EMS processing time increased. The number of patients transferred to ED with CSC was significantly reduced and dispersed. COVID-19 appears to have affected the stroke chain of survival by hindering entry into EDs with stroke centers, the gateway for acute stroke patients.

A longitudinal study of changes of congenital auricular deformity regarding self-correction.

This study aimed to investigate the factors associated with congenital auricular deformities and evaluate the long-term frequency of their self-correction. Ninety newborns were enrolled in the study, and data were collected within 2 weeks after birth and at 1 year. The shape of the auricle was classified into seven categories using a digital image. At 2 weeks after birth, several birth-related factors were evaluated in the auricular deformity and normal groups. At 1 year after birth, the images of auricles were compared with the images at birth, and the changes in the auricle shape were investigated. Congenital auricular deformities were observed in 139 out of 180 ears, and the major type noted was helix rim deformity (47 ears), followed by normal ears (41 ears), and cup ears (33 ears). Male sex was found to have a statistically significant association with the occurrence of auricular deformity. In the longitudinal study, among 43 neonates (86 ears) followed-up 12 months later, the self-correction rate was approximately 50%. The normal auricle and prominent ear increased, helix rim deformity and cup ear decreased significantly. The prognosis of deformity varied depending on the type of deformity. Considering the low self-correction rate in the prominent and cup ears, newborns with these deformities might be recommended to undergo management such as auricle molding technique, as required.

Using lactate dehydrogenase to predict the severity of respiratory distress in term newborn infants with no perinatal asphyxia.

BACKGROUND: We aimed to establish whether knowledge of lactate dehydrogenase (LDH) levels on day 1, as well as the change in these levels in the first three days, could be of clinical benefit in the diagnosis and/or prediction of severity of respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN). METHODS: A retrospective study was conducted on 275 term infants (35 with RDS and 240 with TTN) admitted to the neonatal intensive care unit from January 2014 to June 2019. LDH levels were measured on admission and after three days. RESULTS: Both RDS and TTN groups had elevated LDH levels during admission. LDH levels were significantly higher in the RDS group than in the TTN group on both days. LDH levels in both groups significantly correlated with both the duration of respiratory support required, as well as the number of hospital days. We used these outcomes as a measure of severity of these conditions. CONCLUSIONS: In patients with respiratory distress, it may not be clinically useful to use LDH levels on day 1 to differentiate between RDS and TTN, despite the statistically significant differences, because of the overlapping values. However, LDH levels on day 1 and day 3 may predict the degree and duration of the required respiratory support for both RDS and TTN groups.

Predicting survival time of Korean hepatocellular carcinoma patients using the Cox proportional hazards model: a retrospective study based on big data analysis.

AIM: To predict survival time of Korean hepatocellular carcinoma (HCC) patients by analyzing big data using Cox proportional hazards model. METHODS: Big data of the patients who underwent treatment for HCC from 2008 to 2015, provided by Korea Central Cancer Registry, National Cancer Center, and Ministry of Health and Welfare, were analyzed. A total of 10 742 patients with HCC were divided into two groups, with Group I (3021 patients) confirmed on biopsy and Group II (5563 patients) diagnosed as HCC according to HCC diagnostic criteria as outlined in Korean Liver Cancer Association guidelines. Univariate and multivariate Cox regression analyses were performed to identify independent risk factors of recurrence after treatment and survival status. RESULTS: A total of 3021 patients in Group I and 5563 patients in Group II were included in the study and the difference in survival time between the two groups was statistically significant (P < 0.05). Recurrence was only included in intrahepatic cases, and the rates were 21.2 and 19.8% while the periods from the first treatment to recurrence were 15.57 and 14.19 months, respectively. Age, diabetes, BMI, platelet, alpha-fetoprotein, histologic tumor maximum size, imaging T stage, presence of recurrence, and duration of recurrence were included in multivariate analysis. CONCLUSION: By using nationwide, multicenter big data, it is possible to predict recurrence rate and survival time which can provide the basis for treatment response to develop a predictive program.

Comparison of breast volume change between oncoplastic breast-conserving surgery with radiation therapy and a simultaneous contralateral balancing procedure through the inverted-T scar technique.

BACKGROUND: Reduction mammoplasty or mastopexy is performed as an additional balancing procedure in patients with large or ptotic breasts who undergo breast-conserving surgery (BCS). Radiation therapy on breasts that have undergone surgery may result in changes in the volume. This study presents a comparative analysis of patients who received post-BCS balancing procedures to determine whether volume changes were larger in breasts that received radiation therapy than on the contralateral side. METHODS: Thirty-six participants were selected among patients who received BCS using the inverted-T scar technique between September 2012 and July 2017, were followed up for 2 or more years, and had pre-radiation therapy computed tomography images and post-radiation therapy images taken between 12 and 18 months after completion. The average age of the participants was 53.5 years, their average body mass index was 26.62 kg/m2. RESULTS: The pre- and post-radiation therapy volumes of the breasts receiving BCS were 666.08±147.48 mL and 649.33±130.35 mL, respectively. In the contralateral breasts, the volume before radiation therapy was 637.69±145.72 mL, which decreased to 628.14±166.41 mL after therapy. The volume ratio of the affected to the contralateral breasts was 1.05±0.10 before radiation therapy and 1.06±0.12 after radiation therapy. CONCLUSIONS: The ratio of the volume between the two breasts immediately after surgery and at roughly 18 months postoperatively was not significantly different (P=0.98). For these reasons, we recommend a simultaneous single-stage balancing procedure as a reasonable option for patients who require radiation therapy after BCS without concerns regarding volume change.

What predicts better prognosis in elderly breast cancer patients?

Purpose: As we enter an aging society, the number of elderly patients with breast cancer is increasing. We assessed the prognostic factors for breast cancer recurrence or metastasis in patients over the age of 65 years by analyzing tumor characteristics and long-term clinical outcomes. Methods: In this retrospective study, the data of 286 breast cancer patients aged 65 years and older, who underwent treatment at the Pusan National University Hospital and Pusan National University Yangsan Hospital from 2008 to 2014, were analyzed. The patients were divided into two groups: those with recurrence or metastasis and those without. Cox-regression model was used to analyze the risk factors for recurrence or metastasis. Kaplan-Meier method was used to analyze survival rates by the log-rank test. Results: Among the 286 patients with invasive breast cancer, 43 patients (15.0%) had recurrence or distant metastasis during a median follow-up period of 61 months. Advanced stages of breast cancer and patients who are not adapted to endocrine therapy were associated with poor prognosis. Conclusion: In this study, advanced stages of breast cancer and endocrine therapy were the prognostic factors for breast cancer recurrences or metastases. Early detection of elderly breast cancer generally increases the possibility of diagnosis at an earlier stage, which can lead to a better prognosis. Moreover, endocrine therapy should be administered to elderly patients who manifest favorable intrinsic subtypes of breast cancer.

Attachment distribution of pectoral muscle origins identified in dual-plane breast implant insertion.

BACKGROUND: Implant-based dual-plane augmentation mammoplasty requires accurate separation of the pectoralis major muscle (PMM) at its origins. The authors identified the PMM origins during breast reconstruction surgery with the goal of providing additional information on subpectoral implant insertion for reconstructive or aesthetic purposes. METHODS: This study was conducted on 67 patients who underwent breast reconstruction surgery at the breast center of our hospital between November 2016 and June 2018. In total, 34 left and 39 right hemithoraces were examined. The left and right hemithoraces were each divided into 15 zones to determine the percentage of PMM attachments in each zone. The distribution of PMM origins in each zone was examined to identify any statistically significant differences. RESULTS: There were no statistically significant differences in the origins of the PMM between the right and left hemithoraces. The percentage of attachments increased moving from the fourth to the sixth rib and from the lateral to the medial aspect. CONCLUSIONS: The anatomical findings of this study could be used as a reference for accurate dissection of the origins of the PMM for the preparation of the subpectoral pocket for subpectoral implant placement.

Effects of Intraoperative Low-Dose Ketamine on Persistent Postsurgical Pain after Breast Cancer Surgery: A Prospective, Randomized, Controlled, Double-Blind Study.

BACKGROUND: Compared to acute postsurgical pain, studies regarding the role of ketamine in persistent postsurgical pain (PPSP) are limited. OBJECTIVES: The aim of this clinical trial was to test if intraoperative low-dose ketamine without postoperative infusion would reduce PPSP development after breast cancer surgery. STUDY DESIGN: We used a randomized, double-blinded, placebo study design. SETTING: This study was conducted at Pusan National University Hospital, Republic of Korea, between December 2013 and August 2016. METHODS: A total of 184 patients scheduled for breast cancer surgery were randomly assigned to either the control or ketamine group. Before skin incision, a bolus (0.5 mg/kg of ketamine or placebo), followed by a continuous infusion (0.12 mg/kg/h of ketamine or placebo), was administered until the end of the surgery. The patients were interviewed via telephone 1, 3, and 6 months after surgery. The first question was whether the patient had surgery-related pain. If answered affirmatively, questions from the Numeric Rating Scale for pain at rest (NRSr) and for coughing (NRSd) were also asked. Our primary outcome was the incidence of PPSP at 3 months after surgery. RESULTS: For PPSP analysis, 168 patients were included. The number of patients who experienced pain was significantly lower in the ketamine group at 3 months (86.9% in the control group vs 69.0% in the ketamine group, P = .005) postoperatively. However, the NRSr and NRSd did not differ between the groups throughout the follow-up. LIMITATIONS: There were no postoperative low-dose ketamine infusion groups to compare due to hospital regulations. Dosage of ketamine was too low to reduce the severity of PPSP. And by using propofol and remifentanil for anesthesia, different results can be deduced with volatile anesthetics. Data from written questionnaires would have been more specific than telephone interviews for long-term assessment. CONCLUSIONS: Though intraoperative low-dose ketamine without postoperative infusion significantly reduced the incidence of PPSP up to 3 months after breast cancer surgery, it failed to reduce clinically significant PPSP and improve patients' quality of life. KEY WORDS: Analgesia, breast cancer, chronic pain, ketamine, mastectomy, morphine, pain, postoperative, propofol.

Association Between Weekend Catch-Up Sleep and Metabolic Syndrome with Sleep Restriction in Korean Adults: A Cross-Sectional Study Using KNHANES.

BACKGROUND: Many researchers have identified that adequate sleep duration is linked to the quality of life and metabolic diseases. Nowadays, it is hard to take enough sleep, so weekend catch-up sleep (CUS) may be an alternative option in modern society. To our knowledge, no previous studies reported the association between weekend CUS and metabolic syndrome, especially in the Korean population. OBJECTIVE: We investigated the association between weekend CUS and the prevalence of metabolic syndrome in Korean adults (≥20 years old) with less than 6 hours of average weekday sleep. PATIENTS AND METHODS: A total of 1,453 individuals were selected from the Korean National Health and Nutrition Examination Survey. Weekend CUS was divided into four categories: ≤0 hour, 0-1 hour, 1-2 hours, and ≥2 hours. Odds ratios (ORs) with 95% confidence intervals (CIs) were derived by univariate and multivariate logistic regression analyses. RESULTS: Participants with weekend CUS ≥1 hour had decreased risk of metabolic syndrome in univariate analysis (CUS 1-2 hours: OR: 0.413, 95% CI: 0.301-0.568; CUS ≥2 hours: OR: 0.382, 95% CI 0.296-0.493). Weekend CUS 1-2 hours reduced the risk of metabolic syndrome in multivariate logistic regression analysis (OR: 0.552, 95% CI: 0.369-0.823). Based on the age group analysis, weekend CUS ≥1 hour reduced the metabolic syndrome among those aged 20-39 and 40-65 (20-39: CUS 1-2 hours OR: 0.248, 95% CI: 0.078-0.783, CUS ≥2 hours OR: 0.374, 95% CI: 0.141-0.991; 40-65: CUS 1-2 hours OR: 0.507, 95% CI 0.309-0.832 CUS ≥2 hours OR: 0.638, 95% CI: 0.415-0.981). CONCLUSION: Weekend CUS was associated with a low risk of metabolic syndrome among Korean adults with sleep restriction.