3-Hydroxytanshinone Inhibits the Activity of Hypoxia-Inducible Factor 1-α by Interfering with the Function of α-Enolase in the Glycolytic Pathway.

Tumor cells in hypoxic conditions control cancer metabolism and angiogenesis by expressing HIF-1α. Tanshinone is a traditional Chinese medicine that has been shown to possess antitumor properties and exerts a therapeutic impact on angiogenesis. However, the precise molecular mechanism responsible for the antitumor activity of 3-Hydroxytanshinone (3-HT), a type of tanshinone, has not been fully understood. Therefore, our study aimed to investigate the mechanism by which 3-HT regulates the expression of HIF-1α. Our findings demonstrate that 3-HT inhibits HIF-1α activity and expression under hypoxic conditions. Additionally, 3-HT inhibits hypoxia-induced angiogenesis by suppressing the expression of VEGF. Moreover, 3-HT was found to directly bind to α-enolase, an enzyme associated with glycolysis, resulting in the suppression of its activity. This inhibition of α-enolase activity by 3-HT leads to the blockade of the glycolytic pathway and a decrease in glycolysis products, ultimately altering HIF1-α expression. Furthermore, 3-HT negatively regulates the expression of HIF-1α by altering the phosphorylation of AMP-activated protein kinase (AMPK). Our study's findings elucidate the mechanism by which 3-HT regulates HIF-1α through the inhibition of the glycolytic enzyme α-enolase and the phosphorylation of AMPK. These results suggest that 3-HT holds promise as a potential therapeutic agent for hypoxia-related angiogenesis and tumorigenesis.

Somatodendritic organization of pacemaker activity in midbrain dopamine neurons.

The slow and regular pacemaking activity of midbrain dopamine (DA) neurons requires proper spatial organization of the excitable elements between the soma and dendritic compartments, but the somatodendritic organization is not clear. Here, we show that the dynamic interaction between the soma and multiple proximal dendritic compartments (PDCs) generates the slow pacemaking activity in DA neurons. In multipolar DA neurons, spontaneous action potentials (sAPs) consistently originate from the axon-bearing dendrite. However, when the axon initial segment was disabled, sAPs emerge randomly from various primary PDCs, indicating that multiple PDCs drive pacemaking. Ca2+ measurements and local stimulation/perturbation experiments suggest that the soma serves as a stably-oscillating inertial compartment, while multiple PDCs exhibit stochastic fluctuations and high excitability. Despite the stochastic and excitable nature of PDCs, their activities are balanced by the large centrally-connected inertial soma, resulting in the slow synchronized pacemaking rhythm. Furthermore, our electrophysiological experiments indicate that the soma and PDCs, with distinct characteristics, play different roles in glutamate- induced burst-pause firing patterns. Excitable PDCs mediate excitatory burst responses to glutamate, while the large inertial soma determines inhibitory pause responses to glutamate. Therefore, we could conclude that this somatodendritic organization serves as a common foundation for both pacemaker activity and evoked firing patterns in midbrain DA neurons.

Perilla frutescens Leaf Extract Attenuates Vascular Dementia-Associated Memory Deficits, Neuronal Damages, and Microglial Activation.

Vascular dementia (VaD) is characterized by a time-dependent memory deficit and essentially combined with evidence of neuroinflammation. Thus, polyphenol-rich natural plants, which possess anti-inflammatory properties, have received much scientific attention. This study investigated whether Perilla frutescens leaf extract (PFL) exerts therapeutic efficacy against VaD. Sprague Dawley rats were divided into five groups: SO, sham-operated and vehicle treatment; OP, operated and vehicle treatment; PFL-L, operated and low-dose (30 mg/kg) PFL treatment; PFL-M, operated and medium-dose (60 mg/kg) PFL treatment; and PFL-H, operated and high-dose (90 mg/kg) PFL treatment. Two-vessel occlusion and hypovolemia (2VO/H) were employed as a surgical model of VaD, and PFL was given orally perioperatively for 23 days. The rats underwent the Y-maze, Barnes maze, and passive avoidance tests and their brains were subjected to histologic studies. The OP group showed VaD-associated memory deficits, hippocampal neuronal death, and microglial activation; however, the PFL-treated groups showed significant attenuations in all of the above parameters. Using lipopolysaccharide (LPS)-stimulated BV-2 cells, a murine microglial cell line, we measured PFL-mediated changes on the production of nitric oxide (NO), TNF-α, and IL-6, and the activities of their upstream MAP kinases (MAPKs)/NFκB/inducible NO synthase (iNOS). The LPS-induced upregulations of NO, TNF-α, and IL-6 production and MAPKs/NFκB/iNOS activities were globally and significantly reversed by 12-h pretreatment of PFL. This suggests that PFL can counteract VaD-associated structural and functional deterioration through the attenuation of neuroinflammation.

Water Extract of Mixed Mushroom Mycelia Grown on a Solid Barley Medium Is Protective against Experimental Focal Cerebral Ischemia.

Although the individual consumption of medicinal mushrooms, including Phellinus linteus (PL), Ganoderma lucidum (GL), and Inonotus obliquus (IO), is known to be neuroprotective, the associated mechanisms underlying their therapeutic synergism on focal cerebral ischemia (fCI) have yet to be elucidated. This study aimed to demonstrate the neuroprotective effects of mixed mushroom mycelia (MMM) against experimental fCI. The water-fractions, ethanolic-fractions, and ethyl acetate-fractions of the MMM (PL, GL, and IO) grown in a barley medium using solid-state fermentation techniques were prepared and their protective effects against glutamate-induced excitotoxicity were compared in PC-12 cells. After the identification of the water extracts of MMM (wMMM) as the most suitable form, which possessed the lowest toxicity and highest efficacy, further analyses for evaluating the anti-apoptotic effects of wMMM, including Hoechst 33258-based nuclear staining, fluorescence-activated cell sorting, and reactive oxygen species (ROS) detection assays, were performed. Rats were subjected to a 90 min middle cerebral artery occlusion and reperfusion, after which a wMMM treatment resulted in significant dose-dependent improvements across a number of parameters. Furthermore, measurements of intracellular ROS and levels of antioxidant enzymes revealed a wMMM-mediated ROS attenuation and antioxidant enzyme upregulation. We suggest that wMMM is neuroprotective against fCI through its anti-apoptotic and anti-oxidative effects.

T2 relaxation time shortening in the cochlea of patients with sudden sensory neuronal hearing loss: a retrospective study using quantitative synthetic magnetic resonance imaging.

OBJECTIVES: High cochlear signal intensity on three-dimensional (3D) T2 fluid-attenuated inversion recovery (FLAIR) sequences in patients with sudden sensorineural hearing loss (SSNHL) has been reported. Here, we evaluated the cochlear T2 relaxation time differences in patients with idiopathic SSNHL using quantitative synthetic MRI (SyMRI). METHODS: Twenty-four patients with unilateral SSNHL who underwent precontrast conventional 3D FLAIR and SyMRI were retrospectively included. T1 and T2 relaxation times and the proton density (PD) of the bilateral ears were measured by manually drawn regions of interest. Wilcoxon signed-rank tests and intra- and interobserver correlation analyses were performed. Qualitative analysis was also performed to determine the presence and laterality of the asymmetric high signal intensity on synthetic FLAIR (SyFLAIR) images. RESULTS: The T2 relaxation time was significantly lower in the affected (basal and apico-middle turns) than in the unaffected cochlea (basal turn: 519 ± 181.3 vs. 608.8 ± 203.6, p = 0.042; apico-middle turn: 410.8 ± 163.8 vs. 514.5 ± 186.3, p = 0.037). There were no significant differences in the T1 relaxation time and PD between the affected and unaffected ears (p > 0.05). Additionally, three patients without asymmetric signal intensity on conventional MRI showed asymmetric increased signal intensity in the affected ear on SyFLAIR. CONCLUSIONS: The T2 relaxation time was significantly shorter in the affected than in the unaffected cochlea of patients with idiopathic SSNHL. The SyMRI-derived T2 relaxation time may be a promising imaging marker, suggesting that the changes in inner ear fluid composition are implicated in the idiopathic SSNHL development. KEY POINTS: • T2 relaxation time was significantly lower in the affected than in the unaffected cochlea. • SyFLAIR showed increased lesion conspicuity compared to conventional 3D-FLAIR in detecting asymmetric high signal intensity of the affected side. • SyMRI-derived T2 relaxation time may be a promising imaging marker of the affected ear in patients with idiopathic SSNHL.

Dietary supplement use in Korean children and adolescents, KNHANES 2015-2017.

OBJECTIVE: To date, there have been few studies on dietary supplement (DS) use in Korean children and adolescents, using nationally representative data. This study aimed to investigate the current status of DS use and its related factors, among Korean children and adolescents from the Korean National Health and Nutrition Examination Survey (KNHANES) data. DESIGN: A cross-sectional study. SETTING: Data from the KNHANES 2015-2017. Participants completed 24-h dietary recall interviews, including DS products that the subjects consumed. PARTICIPANTS: The study population was 4380 children and adolescents aged 1-18 years. RESULTS: Approximately 20.3 % of children and adolescents were using DS; the highest use was among children aged 1­3 years old, and the lowest use was among adolescents aged 16­18 years. The most frequently used DS was prebiotics/probiotics, followed by multivitamin/mineral supplements. Factors that were associated with DS use were lower birth weight in children aged <4 years; younger age, higher household income, regular breakfast intake and lower BMI in children aged 4-9 years; and regular breakfast intake and use of nutrition facts label in adolescents aged 10-18 years. Feeding patterns in infancy and having chronic diseases were not associated with DS use. CONCLUSIONS: We report that over 20 % of children and adolescents use DS. Nutritional education for parents and children about proper DS consumption is needed.

Growth in Exclusively Breastfed and Non-exclusively Breastfed Children: Comparisons with WHO Child Growth Standards and Korean National Growth Charts.

BACKGROUND: This study examined the relationship of infant feeding with anthropometric indices of children during their first six years of life relative to the Korean National Growth Charts (KNGC) and the World Health Organization Child Growth Standards (WHO-CGS). METHODS: The study population consisted of 547,669 Korean infants and children who were 6 months-old to 6 years-old (born in 2008-2009) and participated in the National Health Screening Program for Infants and Children. Data on height, weight, and type of feeding during the first 6 months (exclusively breastfed [BF] vs. mixed- or formula-fed [FF]) were analyzed. RESULTS: BF boys and girls were significantly shorter and lighter than FF counterparts from the age of 6 months to 4 years, but these differences were not significant after the age of 4 years. BF boys and girls only had significantly lower body mass index at the age of 2 years. Under the age of 2 years 6 months, and especially under the age of 1 year, BF boys and girls were significantly taller and heavier than the 50th percentile values of the 50th percentile value of the WHO-CGS. CONCLUSION: In this study using large-scaled national data, Korean breastfed children are shorter and lighter by 3 years 6 months-4 years 6 months, but afterward, there is no significant difference from those who had mixed- or formula-feeding. Substantial disparities in the anthropometric indices of Korean infants under the age of 1 compared to KNCG and WHO-CGS were found, regardless of their infantile feeding types. Our results emphasize the importance of constructing a nationwide reference chart based on actual measurements of BF Korean infants.

Two new secondary metabolites isolated from Avena sativa L. (Oat) seedlings and their effects on osteoblast differentiation.

Seedlings of natural crops are valuable sources of pharmacologically active phytochemicals. In this study, we aimed to identify new active secondary metabolites in Avena sativa L. (oat) seedlings. Two new compounds, avenafuranol (1) and diosgenoside (2), along with eight known compounds (3-10) were isolated from the A. sativa L. seedlings. Their chemical structures were elucidated via 1D and 2D NMR spectroscopy, high-resolution ESIMS, IR spectroscopy, optical rotation analysis, and comparisons with the reported literature. The effect of each isolated compound on alkaline phosphatase (ALP) activity for osteoblast differentiation induced by bone morphogenetic protein-2 (BMP-2) was investigated using the C2C12 immortal mouse myoblast cell line. Compounds 1, 4, 6, 8, and 9 induced dose-dependent increases in ALP expression relative to ALP expression in cells treated with only BMP-2, and no cytotoxicity was observed. These results suggest that A. sativa L. seedlings are a natural source of compounds that may be useful for preventing bone disorders.

Trend of Menarcheal Age among Korean Girls.

BACKGROUND: Menarcheal age has been decreasing worldwide. However, few recent studies have observed trends in menarcheal age in larger populations, and the cutoff age for early menarche remains unclear. Therefore, we aimed to analyze recent trends of menarcheal age and to determine the cutoff age of early menarche based on nationally representative data. METHODS: We conducted a cross-sectional study of 351,006 Korean girls aged 12-18 years who were born in 1988-2003 based on the data of the 2006-2015 Korea Youth Risk Behavior Survey. We identified the distribution of age at menarche using the complex sample Cox regression model. Trends in the prevalence of early menarche were determined using the complex sample linear model. RESULTS: Ninety-five percent of all the participants reported they had experienced menarche. The mean menarcheal age was 13.0 years (95% confidence intervals [CIs], 12.92-13.04) for girls born in 1988 and decreased to 12.6 years (95% CI, 12.54-12.61) for girls born in 2003. The cutoff age (the 3rd percentile value) for early menarche was 10.5 years during the study period. The prevalence of early menarche significantly increased from 1.8% in 2006 to 3.2% in 2015 (P-for-trend < 0.001). Downward trends of menarcheal age were noted across all body mass index groups, and this trend was most prominent in the obese group. CONCLUSION: We reported an ongoing downward trend in menarcheal age in Korean girls born in 1988-2003, decreasing by 0.4 years over the 15 years.

Biofunctional soyasaponin Bb in peanut (Arachis hypogaea L.) sprouts enhances bone morphogenetic protein-2-dependent osteogenic differentiation via activation of runt-related transcription factor 2 in C2C12 cells.

Improvement of bone formation is necessary for successful treatment of the bone defects associated with osteoporosis. In this study, we sought to elucidate the osteogenic activity of peanut sprouts and their bioactive components. We found that peanut sprout water extract (PSWE) enhanced bone morphogenetic protein-2-mediated osteoblast differentiation in a dose-dependent manner by stimulating expression of runt-related transcription factor 2 (Runx2) via activation of AKT/MAP kinases. We identified a major component of PSWE, soyasaponin Bb, as the bioactive compound responsible for improvement of anabolic activity. Soyasaponin Bb from PSWE enhanced expression of the osteogenic transcription factor Runx2 and alkaline phosphatase. The soyasaponin Bb content depended on sprouting time of peanut, and the anabolic action of PSWE was dependent on soyasaponin Bb content. Thus, PSWE and soyasaponin Bb have the potential to protect against bone disorders, including osteoporosis.

The Dual Role of Oat Bran Water Extract in Bone Homeostasis Through the Regulation of Osteoclastogenesis and Osteoblast Differentiation.

The number of patients with bone metabolic disorders including osteoporosis is increasing worldwide. These disorders often facilitate bone fractures, which seriously impact the patient's quality of life and could lead to further health complications. Bone homeostasis is tightly regulated to balance bone resorption and formation. However, many anti-osteoporotic agents are broadly categorized as either bone forming or anti-resorptive, and their therapeutic use is often limited due to unwanted side effects. Therefore, safe and effective therapeutic agents are needed for osteoporosis. This study aims to clarify the bone protecting effects of oat bran water extract (OBWE) and its mode of action. OBWE inhibited RANKL (receptor activator of nuclear factor-κB ligand)-induced osteoclast differentiation by blocking c-Fos/NFATc1 through the alteration of I-κB. Furthermore, we found that OBWE enhanced BMP-2-stimulated osteoblast differentiation by the induction of Runx2 via Smad signaling molecules. In addition, the anti-osteoporotic activity of OBWE was also evaluated using an in vivo model. OBWE significantly restored ovariectomy-induced bone loss. These in vitro and in vivo results showed that OBWE has the potential to prevent and treat bone metabolic disorders including osteoporosis.

A Trend in Sudden Sensorineural Hearing Loss: Data from a Population-Based Study.

This is the first study reporting on the incidence and clinical aspects of sudden sensorineural hearing loss (SSNHL) in South Korea. Using Health Insurance Review and Assessment Service data from 2011 to 2015, the monthly incidence of unilateral SSNHL and incidence according to patients' sex, age, and month of diagnosis were investigated. The monthly incidence of unilateral SSNHL increased over the 5-year study period, with a mean annual incidence of 17.76 cases/ 100,000 of the population. The incidence increased with age, with most patients presenting in their 60s. There was a slight female preponderance, with a male-to-female ratio of 1: 1.35. Most new patients were diagnosed in October, and the fewest in January. In conclusion, this large-scale study indicates that unilateral SSNHL has a higher incidence among the elderly, women, and in autumn (i.e., along with colder weather).

Outcome of Cochlear Implantation in Prelingually Deafened Children According to Molecular Genetic Etiology.

OBJECTIVES: About 60% of Korean pediatric cochlear implantees could be genetically diagnosed (GD) and we previously reported that a substantial portion of undiagnosed cases by deafness gene panel sequencing were predicted to have a nongenetic or complex etiology. We aimed to compare the outcomes of cochlear implantation (CI) in GD and genetically undiagnosed (GUD) patients and attempted to determine CI outcomes according to etiology. DESIGN: Ninety-three pediatric cochlear implantees underwent molecular genetic testing. Fifty-seven patients carried pathogenic variants and 36 patients remained GUD after panel sequencing of 204 known or potential deafness genes (TRS-204). Among them, 55 cochlear implantees with reliable speech evaluation results with a follow-up of longer than 24 months were recruited. Longitudinal changes in the audiologic performance were compared between the GD (n = 31) and GUD (n = 24) groups. The GD group was subdivided into cochlear implantee with SLC26A4 mutations (group 1) and cochlear implantee with other genetic etiology (group 2), and the GUD group was subdivided into groups 3 and 4, that is, patients with or without inner ear anomaly, respectively. RESULTS: Group 1 related to SLC26A4 mutations had the highest categories of auditory perception scores among all groups pre- and postoperatively. Group 4 with inner ear anomaly had the lowest categories of auditory perception scores. At 24 months post-CI, the group 2 with another genetic etiology had significantly better outcomes than molecularly undiagnosed group 3, which had with the same condition as group 2 except that the candidate gene was not detected. This finding was recapitulated when we limited cases to those that underwent CI before 24 months of age to minimize age-related bias at implantation. Furthermore, on extending the follow-up to 36 months postoperatively, this tendency became more prominent. Additionally, our preliminary clinical data suggest a narrower sensitive window period for good CI outcomes for implantees with OTOF mutation rather than the GJB2 and other genes. CONCLUSIONS: Current molecular genetic testing including deafness panel sequencing helps to predict the 2-year follow-up outcomes after CI in prelingually deafened children. GD cochlear implantees show better functional outcomes after CI than undiagnosed cochlear implantees as determined by deafness panel sequencing, suggesting a genotype-functional outcome correlation. The genetic testing may provide a customized optimal window period in terms of CI timing for favorable outcome according to genetic etiology.

Age at menarche in Korean adolescents: trends and influencing factors.

BACKGROUND: An increased incidence of central precocious puberty has been recently reported in South Korea, which suggests an ongoing downward trend in pubertal development in the Korean population. We aimed to verify the trend in age at menarche in young Korean women during the last decade and associated factors. METHODS: We analyzed a population-based sample of 3409 Korean girls, aged 10-18 years, using data from the Korean National Health and Nutrition Examination Surveys (KNHANES) II (2001), III (2005), IV (2007-2009), and V (2010 and 2011). Average age at menarche was studied using the Kaplan-Meier survival method and predictors were analyzed using Cox proportional hazards model. The percentage of subjects who had experienced menarche at each age level was compared by using the Cochran-Armitage test. RESULTS: Overall mean age at menarche was 12.7 years. The percentage of subjects who experienced menarche before the age of 12 years was 21.4 % in 2001 but increased to 34.6 % in 2010/2011 (p < 0.01). In addition, the percentage of girls who experienced menarche before the age of 14 years increased from 76 % in 2001 to 92 % in 2010/2011 (p < 0.005). Adolescents whose mothers who had experienced early menarche (HR 1.48, 95 % CI [1.22-1.80]), and adolescents who were overweight (HR 1.24, 95 % CI [1.04-1.49]) were more likely to have experienced menarche. Additionally, underweight adolescents (HR 0.27, 95 % CI [0.12-0.60]) and adolescents who had a mother having late menarche (HR 0.68, 95 % CI [0.59-0.79]) were expected to have late menarche. None of the socioeconomic factors assessed in our study showed an association with age at menarche. CONCLUSIONS: A downward trend in age at menarche was defined in Korean adolescents during the last decade. Furthermore, influences of genetic and nutritional parameters on individual variance in age at menarche were defined.

Identification of a novel truncation mutation of EYA4 in moderate degree hearing loss by targeted exome sequencing.

The EYA4 gene encodes a 640-amino-acid protein that serves as a transcription factor. This protein contains a highly conserved Eya domain (eya-HR) and a variable domain (eya-VR). Mutations of this gene are known to cause postlingual and progressive sensorineural hearing loss, either as non-syndromic (DFNA10) or syndromic hearing loss, depending on the location of truncation of the mutant protein. Since our previous report, we have recruited 14 families segregating autosomal dominant moderate SNHL. A thorough medical history and physical examination including evaluation of heart problems ruled out any syndromic features in these families. Screening of EYA4 was performed by targeted exome sequencing of 134 known deafness genes (TES-134) from the probands. After basic filtering of the variants, we identified one proband who carried a novel truncation mutation, c.1194delT (p.Met401TrpfsX3) of EYA4, making the frequency of DFNA10 to be 7.14 % (1/14) in Koreans. The variant co-segregated perfectly with a slightly down-sloping, moderate degree of SNHL in the family (SH117), and was not detected in any of the 592 normal control chromosomes. This variant is likely to generate protein products that are truncated just downstream of the eya-VR domain. None of the three affected family members showed any syndromic features, including cardiac problems, which was compatible with a previous genotype-phenotype correlation. The identification of a novel EYA4 truncation mutation associated with DFNA10, rather than syndromic hearing loss, supports a previously reported genotype-phenotype correlation in this gene. Considering its detection rate, EYA4 mutations should be suspected in hereditary moderate hearing loss with a corresponding audiologic configuration, and a cardiac examination should be included in the initial evaluation.

Balance between the proximal dendritic compartment and the soma determines spontaneous firing rate in midbrain dopamine neurons.

Midbrain dopamine (DA) neurons are slow intrinsic pacemakers that require the elaborate composition of many ion channels in the somatodendritic compartments. Understanding the major determinants of the spontaneous firing rate (SFR) of midbrain DA neurons is important because they determine the basal DA levels in target areas, including the striatum. As spontaneous firing occurs synchronously at the soma and dendrites, the electrical coupling between the soma and dendritic compartments has been regarded as a key determinant for the SFR. However, it is not known whether this somatodendritic coupling is served by the whole dendritic compartments or only parts of them. In the rat substantia nigra pars compacta (SNc) DA neurons, we demonstrate that the balance between the proximal dendritic compartment and the soma determines the SFR. Isolated SNc DA neurons showed a wide range of soma size and a variable number of primary dendrites but preserved a quite consistent SFR. The SFR was not correlated with soma size or with the number of primary dendrites, but it was strongly correlated with the area ratios of the proximal dendritic compartments to the somatic compartment. Tetrodotoxin puff and local Ca(2+) perturbation experiments, computer simulation, and local glutamate uncaging experiments suggest the importance of the proximal dendritic compartments in pacemaker activity. These data indicate that the proximal dendritic compartments, not the whole dendritic compartments, play a key role in the somatodendritic balance that determines the SFR in DA neurons.

Prevalence of 25-hydroxyvitamin D deficiency in Korean adolescents: association with age, season and parental vitamin D status.

OBJECTIVE: We aimed to assess the prevalence and associated factors of vitamin D deficiency in healthy adolescents and to determine parent-adolescent association in vitamin D status. DESIGN: A cross-sectional study. SETTING: Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2008-2009. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using 125I-labelled RIA kits. Vitamin D deficiency in adolescents was defined as 25(OH)D level <27·5 nmol/l, and 25(OH)D levels between 27·5 and <50 nmol/l were considered insufficient. For the parents, vitamin D deficiency was defined as 25(OH)D level <50 nmol/l. SUBJECTS: The study population consisted of 2062 adolescents (1095 boys, 967 girls; aged 10-18 years) and their parents (1005 fathers, 1341 mothers). RESULTS: Overall, 13·4% of adolescents (boys 11·7%, girls 15·4%) were 25(OH)D deficient, 54·7% were 25(OH)D insufficient. Prevalence of vitamin D deficiency increased with age (P < 0·0001). Parental vitamin D deficiency was more prevalent in vitamin D-deficient adolescents than in non-deficient adolescents (all P < 0·0001). In multivariate logistic regression analyses, predictors for vitamin D deficiency were senior high school students (OR = 3·45-4·33), winter/spring season (OR = 3·18-5·11/5·35-7·36) and parental vitamin D deficiency (OR = 1·78-4·88; all P < 0·05). CONCLUSIONS: Vitamin D insufficiency is prevalent among healthy Korean adolescents and the parent-offspring association warrants vitamin D screening for family members of deficient individuals.

Inadequate calcium intake is highly prevalent in Korean children and adolescents: the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2010.

OBJECTIVE: The present study aimed to assess the adequacy of Ca intake and major food sources of Ca in Korean children and adolescents. DESIGN: A cross-sectional study. SETTING: Data from the Korean National Health and Nutrition Examination Survey (KNHANES) 2007-2010. We analysed the daily Ca intake, major food sources of Ca and the prevalence of inadequate Ca intake in the study population. Ca intake was categorized as inadequate when the participant's daily Ca intake was less than the Estimated Average Requirement. Subject The study population consisted of 7233 children and adolescents (3973 boys, 3260 girls; aged 1-18 years). RESULTS: Mean Ca intake was 510·2 mg/d in boys and 431·7 mg/d in girls. Overall, 75·0 % of adolescents (boys 71·6 %, girls 79·1 %) had inadequate Ca intake. The prevalence of inadequate Ca intake increased significantly from toddlers (45-55 %) to adolescents (78-86 %) in both genders. The highest ranked food sources for Ca were dairy products (35·0 %), followed by vegetables (17·3 %), grains (11·3 %) and seafood (9·9 %). Ca intake from dairy products decreased significantly from 57 % in toddlers to 30 % in adolescents, while Ca intakes from other foods increased with age. CONCLUSIONS: Inadequate Ca intake is highly prevalent and increased with age in Korean children and adolescents. It should be emphasized to encourage children and adolescents to eat more Ca-rich products to meet their Ca needs.

Associations between serum perfluoroalkyl and polyfluoroalkyl concentrations and diabetes mellitus in the Korean general population: Insights from the Korean National Environmental Health Survey 2018-2020.

AIMS: Recent epidemiologic research has examined the relationship between perfluoroalkyl and polyfluoroalkyl substances (PFAS) and diabetes mellitus with inconclusive findings. In this cross-sectional study, we aimed to explore the association between serum PFAS concentrations and the prevalence of prediabetes and pre-diagnostic diabetes in the general Korean population as well as the combined effects of exposure to mixed PFAS compounds. METHODS: We analyzed data from participants aged ≥19 years enrolled in the Korean National Environmental Health Survey Cycle 4 (2018-2020). Individuals diagnosed with diabetes were excluded to minimize potential bias. We identified cases of pre-diagnostic diabetes based on the HbA1c level ≥6.5% and prediabetes as HbA1c levels of 5.7-6.49%. Serum concentrations of PFAS, including perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDeA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS), were quantified using high-performance liquid chromatography-tandem mass spectrometry. Survey-weighted logistic regression models were used to assess the relationships between PFAS levels and diabetes risk, adjusting for covariates. Additionally, Bayesian kernel machine regression (BKMR) was used to investigate the combined effects of exposure to mixed PFAS compounds. RESULTS: In the study population excluding participants with diagnosed diabetes (n = 2709), the prevalence of pre-diagnostic diabetes and prediabetes was 4.8% and 30.1%, respectively. Significant positive associations were found between serum PFHxS and PFOS quartiles and pre-diagnostic diabetes risk. Likewise, among those without diagnosed or pre-diagnostic diabetes (n = 2579), the highest quartiles of PFDeA, PFHxS, and PFOS and the overall PFAS level were associated with an increased risk of prediabetes compared with the lowest quartiles. BKMR analysis revealed a significant positive association between overall serum PFAS level and prediabetes risk, which was most marked for PFOS. CONCLUSIONS: These findings highlight the potential health implications of PFAS exposure and prediabetes risk. Further research is needed to validate these associations and identify potential mechanistic pathways.