Woong Hwan Choi

Vitamin D Insufficiency in Korea—A Greater Threat to Younger Generation: The Korea National Health and Nutrition Examination Survey (KNHANES) 2008

CONTEXT Vitamin D status in the Korean population has not been adequately determined. OBJECTIVE To investigate the vitamin D status and the prevalence of vitamin D insufficiency in the Korean population, and also identify the predictors for vitamin D insufficiency in Korea. DESIGN AND SETTING The Fourth Korea National Health and Nutrition Examination Surveys (KNHANES IV) in the Korean population conducted in 2008. PARTICIPANTS 3,047 males and 3,878 females aged 10 years and older selected in all the 16 administrative districts of South Korea. MAIN OUTCOME MEASURES Serum 25-hydroxyvitamin D [25(OH)D] levels and the prevalence of vitamin D insufficiency defined as serum 25(OH)D level of less than 20 ng/ml. RESULTS Vitamin D insufficiency was found in 47.3% of males and 64.5% of females, whereas only 13.2% of male and 6.7% of female population had a serum 25(OH)D level of greater than 30 ng/ml. Vitamin D insufficiency was most prevalent in the age of 20-29, with a rate of 65.0% in males and 79.9% in females, and least prevalent in the age of 60-69 in males and 50-59 in females. Those who work usually indoors were more predisposed to vitamin D insufficiency. In the adult population, predictors for vitamin D insufficiency included young age groups, spring and winter seasons, living in an urban area, and indoor occupations. CONCLUSIONS Vitamin D insufficiency is very common, and it is now a greater threat to the younger generation in Korea. Current recommendations for vitamin D intakes for Koreans are inadequate, especially for the youth.

Effects of seaweed supplementation on blood glucose concentration, lipid profile, and antioxidant enzyme activities in patients with type 2 diabetes mellitus

The present study was carried out to evaluate the physiological effects of seaweed supplementation on blood glucose levels, lipid profile, and antioxidant enzyme activities in subjects with type 2 diabetes mellitus. Subjects were randomized into either a control group or a seaweed supplementation group. Pills with equal parts of dry powdered sea tangle and sea mustard were provided to the seaweed supplementation group three times a day for 4 weeks. Total daily consumption of seaweed was 48 g. We found that total dietary fiber intake was 2.5 times higher in subjects receiving seaweed supplementation than in the control group. Accordingly, fasting blood glucose levels (p<0.01) and 2-hour postprandial blood glucose measurements (p<0.05) were decreased significantly in those ingesting seaweed. Furthermore, the serum concentrations of triglycerides were decreased and high-density lipoprotein cholesterol was increased significantly in seaweed supplement group (p<0.05). However, the concentrations of total cholesterol and low-density lipoprotein cholesterol were not affected by seaweed supplementation. The level of thiobarbituric acid reactive substances in erythrocytes was significantly lower with seaweed supplementation compared to controls (p<0.05). Catalase and glutathione peroxidase activities with seaweed supplementation were higher than the controls (p<0.05), but superoxide dismutase activity was not affected. We, therefore, conclude that ingestion of seaweed influences glycemic control, lowers blood lipids, and increases antioxidant enzyme activities.

Comparative study of robotic versus endoscopic thyroidectomy by a gasless unilateral axillo‐breast or axillary approach

Robotic thyroidectomy and conventional endoscopic thyroidectomy have not been thoroughly compared. In this study, we compared the potential advantages of robotic versus endoscopic thyroidectomy.

Visceral adipose tissue as a predictor for metabolic risk factors in the Korean population.

Aims  Visceral adipose tissue (VAT) accumulation is closely associated with an increased risk of cardiovascular disease. We have investigated the appropriate VAT cut‐off values for predicting metabolic risk factors in the Korean population.

Scaling of adult body weight to height across sex and race/ethnic groups: relevance to BMI

BACKGROUND Body mass index (BMI) is formulated on the assumption that body weight (BW) scales to height with a power of 2 (BW∝height(2)), independent of sex and race-ethnicity. Powers differing from 2 are observed in studies of selected samples, thus raising the question if BMI is a generalizable metric that makes BW independent of height across populations. OBJECTIVES The objectives were to test the hypothesis that adult BW scales to height with a power of 2 independent of sex and race-ethnicity and to advance an understanding of BMI as a measure of shape by extending allometric analyses to waist circumference (WC). DESIGN We conducted cross-sectional subject evaluations, including body composition, from the NHANES and the Korean NHANES (KNHANES). Variations of the allometric model (Y = αX(β)) were used to establish height scaling powers (β ± SE) across non-Hispanic white and black, Mexican American, and Korean men and women. RESULTS Exploratory analyses in population samples established age and adiposity as important independent determinants of height scaling powers (i.e., β). After age and adiposity in the next series of analyses were controlled for, BW scaling powers were nonsignificantly different between race/ethnic groups within each sex group; WC findings were similar in women, whereas small but significant between-race differences were observed in the men. Sex differences in β values were nonsignificant except for BW in non-Hispanic blacks and WC in Koreans (P < 0.05). Nationally representative powers for BW were (NHANES/KNHANES) 2.12 ± 0.05/2.11 ± 0.06 for men and 2.02 ± 0.04/1.99 ± 0.06 for women and for WC were 0.66 ± 0.03/0.67 ± 0.05 for men and 0.61 ± 0.04/0.56 ± 0.05 for women. CONCLUSIONS Adult BW scales to height with a power of ∼2 across the 8 sex and race/ethnic groups, an observation that makes BMI a generalizable height-independent measure of shape across most populations. WC also follows generalizable scaling rules, a finding that has implications for defining body shape in populations who differ in stature.

Optimal surgical extent of lateral and central neck dissection for papillary thyroid carcinoma located in one lobe with clinical lateral lymph node metastasis

BackgroundThe indications and extent of cervical lymph node dissection in papillary thyroid carcinoma (PTC) are still being debated. The aim of this study was to analyze the patterns of cervical lymph node metastasis in the lateral and central compartment and related factors and suggest the optimal extent of lateral and central neck dissection for PTC patients with clinical lateral lymph node metastasis.MethodsWe retrospectively analyzed 72 patients with unilateral PTC who underwent therapeutic lateral neck dissections with concomitant total thyroidectomy and central neck dissection between January 2001 and December 2009.ResultsThe 72 patients underwent 79 sides of therapeutic lateral neck dissection. The most frequent metastatic level in the ipsilateral lateral compartment was level IV (75.0%), followed by level III (69.4%), level II (56.9%) and level V (20.8%). Multiple level metastases were common (77.8%) and were correlated with tumor size (≥ 10 mm). The central compartment lymph node metastasis rate was 87.5%, including 26.4% of contralateral central compartment metastases.ConclusionIn PTC patients with clinical lateral lymph node metastasis, the optimal extent of lateral and central neck dissection should include levels II, III, IV and V as well as the bilateral central compartment.

Scaling of adult regional body mass and body composition as a whole to height: Relevance to body shape and body mass index

Adult body mass (MB) empirically scales as height (Ht) squared (MB ∝ Ht2), but does regional body mass and body composition as a whole also scale as Ht2? This question is relevant to a wide range of biological topics, including interpretation of body mass index (BMI).

Atrophy of brown adipocytes in the adult mouse causes transformation into white adipocyte-like cells

Adipose tissue is an important endocrine regulator of glucose metabolism and energy homeostasis. Researches have focused on this tissue not only as a target for pharmacotherapy of obesity and insulin resistance but also as an endocrine tissue with leptin secretion and high insulin sensitivity. Brown adipose tissue (BAT) additionally plays a unique role in thermoregulation through the mitochondrial uncoupling protein 1 (UCP1), which uncouples oxidative phosphorylation. As a genetic tissue ablation model of BAT, we made transgenic mice expressing herpes simplex virus thymidine kinase (HSV-TK) driven by the brown adipocyte- specific UCP1 minimal regulatory element. The HSV-TK transgene was expressed specifically in BAT and more than 35% increase of apoptosis was induced by ganciclovir (GCV) treatment. Nevertheless, the expression level was not high enough to induce BAT ablation in GCV-treated adult mice. Importantly, however, we found that brown adipocytes in the periphery of interscapular BAT were transformed into white adipocyte-like unilocular cells. These cells express white adipocyte-specific leptin protein but are different in the ultrastructure of mitochondria from classical white adipocytes. Our data indicates that atrophy of BAT causes transformation into white adipocyte-like cells in the adult mouse and also suggests that further molecular understanding of adipocyte plasticity using our transgenic mouse model might be beneficial for the development of anti-obesity/anti-diabetic therapies.

Variant angina in moyamoya disease - a correlative etiology and different presentation: a case report

IntroductionMoyamoya disease is characterized by progressive steno-occlusive changes of the distal internal carotid and developed collateral vasculature, so called ‘moyamoya’ vessels at the base of the brain. Variant angina is a rare occurrence in patients with moyamoya disease.Case presentationHere we report the case of a 41-year-old Korean woman who developed chest pain after indirect revascularization surgery of moyamoya disease. A treadmill test and an exercise stress echocardiograph showed positive results, but there was no significant major coronary arteries stenosis. Suspicious of vasospasm, we conducted an ergonovine spasm stimulation test, which demonstrated tight stenosis of her proximal left anterior descending artery. At the site of spasm, intravascular ultrasound virtual histology showed intraluminal fibrous plaque.ConclusionPhysicians who follow up patients with moyamoya disease would need to be aware of the possibility of cardiac ischemia as well as neurological manifestations.

Partial Androgen Insensitivity Syndrome Presenting with Gynecomastia

Gynecomastia is a benign enlargement of the male breast caused by the proliferation of glandular breast tissue. Determining the various causes of gynecomastia such as physiological causes, drugs, systemic diseases, and endocrine disorders is important. Androgen insensitivity syndrome (AIS) is a rare endocrine disorder presenting with gynecomastia and is a disorder of male sexual differentiation caused by mutations within the androgen receptor gene. All individuals with AIS have the 46 XY karyotype, although AIS phenotypes can be classified as mild, partial or complete and can differ among both males and females including ambiguous genitalia or infertility in males. We experienced a case of partial AIS presenting with gynecomastia and identified the androgen receptor gene mutation.