Interim Estimates of 2023–2024Seasonal Influenza Vaccine Effectiveness Among Adults in Korea

In the 2023–2024 season, the influenza epidemic in South Korea peaked earlier than in recent years. In this study, we aimed to estimate the interim vaccine effectiveness (VE) of the influenza vaccination to prevent influenza during the early season. From November 1, 2023, to December 31, 2023, we enrolled 2,632 subjects with influenza-like illness from eight hospitals participating in hospital-based influenza morbidity and mortality surveillance. A retrospective test-negative case-control study was conducted to estimate the VE. The results showed an adjusted VE of 22.5% (95% confidence interval [CI], 6.6 to 35.8) for the total population. The adjusted VE was 22.3% (95% CI, 6.1 to 35.7) for influenza A and 9.4% (95% CI, −51.3 to 45.7) for influenza A/H1N1. Full results of the analysis will be reported.

Effectiveness of Bivalent mRNA Booster Vaccine Against COVID-19 in Korea

Background@#Bivalent booster mRNA vaccines containing the omicron-variant strains have been introduced worldwide in the autumn of 2022. Nevertheless, the omicron subvariants evoked another large coronavirus disease 2019 (COVID-19) pandemic wave in late 2022 and early 2023. @*Methods@#A retrospective, test-negative, case-control study was conducted to estimate the vaccine effectiveness (VE) of bivalent COVID-19 vaccines in 8 university hospitals between January and February 2023. The case and control groups were divided based on nasopharyngeal COVID-19 real-time polymerase chain reaction results and matched based on age, sex, hospital, and date (week) of the test performed. The VE of the BA.1- or BA.4/BA.5-based mRNA vaccines were estimated. VE was calculated using the 1−adjusted odds ratio from multivariable logistic regression. @*Results@#In total, 949 patients and 947 controls were enrolled in this study. VE for the BA.4/ BA.5-based bivalent mRNA vaccine was 43% (95% confidence interval [CI], 17, 61%). In subgroup analysis based on age and underlying medical conditions, BA.4/BA.5-based bivalent mRNA vaccine was effective against old adults aged ≥ 65-years (VE, 55%; 95% CI, 23, 73%) and individuals with comorbidities (VE, 54%; 95% CI, 23, 73%). In comparison, the BA.1-based bivalent mRNA vaccine did not demonstrate statistically significant effectiveness (VE, 25%; 95% CI, −8, 49%). @*Conclusion@#The BA.4/BA.5-based bivalent mRNA booster vaccine provided significant protection against COVID-19 in the Korean adults, especially in the older adults aged ≥ 65 years and in individuals with underlying medical conditions.

Association between Sleep and Loneliness in the Elderly Living Alone / 정신신체의학

Objectives@#：Loneliness and poor sleep quality are common phenomena in old age and are associated with negative physical and mental health. However, little is known regarding the relation between loneliness and sleep quality. The aim of this study was to examine the association of loneliness and sleep quality among the elderly living alone. @*Methods@#：This is a cross-sectional study that enrolled 1,090 subjects who are the community-residing elderly living alone. Sociodemographic status, medical condition, cognition, mood disorder, sleep quality and levels of loneliness were collected using a self-administered questionnaire and a specific semi-structured interview con-ducted by trained nurses. Descriptive statistics were used to analyze data regarding sociodemographic variable and loneliness. Univariate and Multivariate regression analyses were applied to examine the association between loneliness and sleep quality after adjustment for multiple confounding variables. @*Results@#：The Pittsburgh Sleep Quality Index (PSQI) mean score of “lonely group” (9.2±4.2) was signifi-cantly higher than that of “not lonely group” (7.3±3.7) (student-t test, p<0.001). Loneliness was significantly as-sociated with PSQI (standardized β= 0.065, p=0.025), sleep disturbance (standardized β=0.086, p=0.005), use of sleep medication (standardized β= 0.065, p=0.034) after adjustment for possible confounding variables including sex and mood disorder. @*Conclusions@#：Loneliness was associated with sleep disturbance and this finding implied negative impact of loneliness on sleep quality of older adults. Public health promotion efforts to reduce loneliness may improve sleep quality and mental health in the elderly living alone.

Discriminatory performance of insulin-like growth factor 1 and insulin-like growth factor binding protein-3 by correlating values to chronological age, bone age, and pubertal status for diagnosis of isolated growth hormone deficiency

Purpose@#The discriminatory performance of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated by correlating their values with chronological age (CA), bone age (BA), and pubertal status (PS) for diagnosis of isolated growth hormone deficiency (IGHD). @*Methods@#We evaluated IGF-1 and IGFBP-3 levels in 310 short-stature subjects subdivided into 2 groups: IGHD (n=31) and non-IGHD (n=279). IGF-1 and IGFBP-3 were assayed using immune-radiometric assay and transformed into standard deviation score (SDS) according to CA, BA, and PS. @*Results@#The highest sensitivity was found in IGF-1-SDS for CA and IGFBP-3-SDS for CA (22.6% and 30.0%, respectively). The highest specificity was found in IGF-1-SDS for PS and IGFBP-3-SDS for PS (98.2% and 94.4%, respectively). Groups with the highest positive predictive values were IGF-1-SDS for BA and IGFBP-3-SDS for BA (10.9% and 5.1%, respectively). Highest negative predictive values were seen in IGF-1-SDS for CA and IGFBP-3-SDS for CA (98.4% and 98.4%, respectively). @*Conclusion@#IGF-1-SDS for CA, instead of IGF-1-SDS for BA or PS, could be used as a standard variable for IGHD screening. The sufficiently high specificity of IGF-1-SDS for PS suggests that this value is a useful tool for identification of IGHD.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

Purpose@#Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and ‘fixed cutoff point’ (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS). @*Methods@#Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010–2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP. @*Results@#Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweightormal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR. @*Conclusion@#The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Association between Sleep and Loneliness in the Elderly Living Alone / 정신신체의학

Objectives@#：Loneliness and poor sleep quality are common phenomena in old age and are associated with negative physical and mental health. However, little is known regarding the relation between loneliness and sleep quality. The aim of this study was to examine the association of loneliness and sleep quality among the elderly living alone. @*Methods@#：This is a cross-sectional study that enrolled 1,090 subjects who are the community-residing elderly living alone. Sociodemographic status, medical condition, cognition, mood disorder, sleep quality and levels of loneliness were collected using a self-administered questionnaire and a specific semi-structured interview con-ducted by trained nurses. Descriptive statistics were used to analyze data regarding sociodemographic variable and loneliness. Univariate and Multivariate regression analyses were applied to examine the association between loneliness and sleep quality after adjustment for multiple confounding variables. @*Results@#：The Pittsburgh Sleep Quality Index (PSQI) mean score of “lonely group” (9.2±4.2) was signifi-cantly higher than that of “not lonely group” (7.3±3.7) (student-t test, p<0.001). Loneliness was significantly as-sociated with PSQI (standardized β= 0.065, p=0.025), sleep disturbance (standardized β=0.086, p=0.005), use of sleep medication (standardized β= 0.065, p=0.034) after adjustment for possible confounding variables including sex and mood disorder. @*Conclusions@#：Loneliness was associated with sleep disturbance and this finding implied negative impact of loneliness on sleep quality of older adults. Public health promotion efforts to reduce loneliness may improve sleep quality and mental health in the elderly living alone.

Discriminatory performance of insulin-like growth factor 1 and insulin-like growth factor binding protein-3 by correlating values to chronological age, bone age, and pubertal status for diagnosis of isolated growth hormone deficiency

Purpose@#The discriminatory performance of insulin-like growth factor 1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) was investigated by correlating their values with chronological age (CA), bone age (BA), and pubertal status (PS) for diagnosis of isolated growth hormone deficiency (IGHD). @*Methods@#We evaluated IGF-1 and IGFBP-3 levels in 310 short-stature subjects subdivided into 2 groups: IGHD (n=31) and non-IGHD (n=279). IGF-1 and IGFBP-3 were assayed using immune-radiometric assay and transformed into standard deviation score (SDS) according to CA, BA, and PS. @*Results@#The highest sensitivity was found in IGF-1-SDS for CA and IGFBP-3-SDS for CA (22.6% and 30.0%, respectively). The highest specificity was found in IGF-1-SDS for PS and IGFBP-3-SDS for PS (98.2% and 94.4%, respectively). Groups with the highest positive predictive values were IGF-1-SDS for BA and IGFBP-3-SDS for BA (10.9% and 5.1%, respectively). Highest negative predictive values were seen in IGF-1-SDS for CA and IGFBP-3-SDS for CA (98.4% and 98.4%, respectively). @*Conclusion@#IGF-1-SDS for CA, instead of IGF-1-SDS for BA or PS, could be used as a standard variable for IGHD screening. The sufficiently high specificity of IGF-1-SDS for PS suggests that this value is a useful tool for identification of IGHD.

Comparison of different criteria for the definition of insulin resistance and its relationship to metabolic risk in children and adolescents

Purpose@#Childhood obesity frequently persists into adulthood and is associated with insulin resistance (IR) and increased long-term morbidity and mortality. We compared IR criteria concerning 'age-specific cutoff point' (ACOP) and ‘fixed cutoff point’ (FCOP) for the identification of IR and investigated their correlation with metabolic syndrome (MS). @*Methods@#Data were acquired from the 5th Korea National Health and Nutrition Examination Survey (2010–2011). Participants ranged from 10 to 17 years of age and underwent fasting plasma glucose, insulin concentration, and lipid panel measurements. High fasting plasma insulin levels or increased homeostatic model assessment insulin resistance (HOMA-IR) were defined as IR. We analyzed MS and IR frequencies according to FCOP or ACOP. @*Results@#Among 719 participants, 165 (22.9%) were overweight or obese based on their body mass index. We found no prevalence of MS in underweightormal weight participants and 12.7% prevalence rate in overweight or obese participants. IR according to ACOP was more closely associated with MS than IR according to FCOP. No differences were found in predicting the frequency of MS using FCOP or ACOP in both fasting plasma insulin and HOMA-IR. @*Conclusion@#The frequency of MS in participants with IR defined using ACOP and FCOP was similar. However, IR using ACOP was more closely associated with MS than IR using FCOP.

Dilated cardiomyopathy with Graves disease in a young child

Graves disease (GD) can lead to complications such as cardiac arrhythmia and heart failure. Although dilated cardiomyopathy (DCMP) has been occasionally reported in adults with GD, it is rare in children. We present the case of a 32-month-old boy with DCMP due to GD. He presented with irritability, vomiting, and diarrhea. He also had a history of weight loss over the past few months. On physical examination, he had tachycardia without fever, a mild diffuse goiter, and hepatomegaly. The chest radiograph showed cardiomegaly with pulmonary edema, while the echocardiography revealed a dilated left ventricle with an ejection fraction (EF) of 28%. The thyroid function test (TFT) showed elevated serum T3 and decreased thyroid stimulating hormone (TSH) levels. The TSH receptor autoantibody titer was elevated. He was diagnosed with DCMP with GD; treatment with methylprednisolone, diuretics, inotropics, and methimazole was initiated. The EF improved after the TFT normalized. At follow-up several months later, although the TFT results again showed evidence of hyperthyroidism, his EF had not deteriorated. His cardiac function continues to remain normal 1.5 months after treatment was started, although he still has elevated T3 and high TSH receptor antibody titer levels due to poor compliance with drug therapy. To summarize, we report a young child with GD-induced DCMP who recovered completely with medical therapy and, even though the hyperthyroidism recurred several months later, there was no relapse of the DCMP.

Dilated cardiomyopathy with Graves disease in a young child

Graves disease (GD) can lead to complications such as cardiac arrhythmia and heart failure. Although dilated cardiomyopathy (DCMP) has been occasionally reported in adults with GD, it is rare in children. We present the case of a 32-month-old boy with DCMP due to GD. He presented with irritability, vomiting, and diarrhea. He also had a history of weight loss over the past few months. On physical examination, he had tachycardia without fever, a mild diffuse goiter, and hepatomegaly. The chest radiograph showed cardiomegaly with pulmonary edema, while the echocardiography revealed a dilated left ventricle with an ejection fraction (EF) of 28%. The thyroid function test (TFT) showed elevated serum T3 and decreased thyroid stimulating hormone (TSH) levels. The TSH receptor autoantibody titer was elevated. He was diagnosed with DCMP with GD; treatment with methylprednisolone, diuretics, inotropics, and methimazole was initiated. The EF improved after the TFT normalized. At follow-up several months later, although the TFT results again showed evidence of hyperthyroidism, his EF had not deteriorated. His cardiac function continues to remain normal 1.5 months after treatment was started, although he still has elevated T3 and high TSH receptor antibody titer levels due to poor compliance with drug therapy. To summarize, we report a young child with GD-induced DCMP who recovered completely with medical therapy and, even though the hyperthyroidism recurred several months later, there was no relapse of the DCMP.

Elemental analysis of the liver, kidney, and intestine tissues from a Hodgson's bat (Myotis formosus tsuensis)

Hodgson's bats are critically endangered in South Korea. This study analyzed the concentrations of elements in liver, kidney, and intestine tissues from a Hodgson's bat found dead in the wild. The concentrations of essential elements followed the order Fe > Zn > Cu >Mn > Se in the three tissues. Hg was detected at the highest concentrations among the non-essential elements analyzed in the liver and kidney tissues, while As was the most highly concentrated non-essential element in the intestine. To the best of our knowledge, this is the first study of tissue element concentrations in Hodgson's bats.