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Kyung Mook Choi

Publications and source records attributed to Kyung Mook Choi.

11 recordsLinked to original sources
PubMed2025

Impact of Muscle Quality on Muscle Strength and Physical Performance Beyond Muscle Mass or Diabetes Status.

BACKGROUND: Muscle quality, represented by myosteatosis, is recognized as an important factor in sarcopenia. In this study, we aimed to determine the associations between myosteatosis, muscle strength and physical performance among the elderly South Korean population. METHODS: We included 1440 participants (mean age 62.7&#x2009;&#xb1;&#x2009;6.2&#x2009;years) from the Korean Genome and Epidemiology Study (KoGES). Based on the computed tomography attenuation of mid-thigh imaging, the total muscle area (TMA), normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA) and inter-intramuscular adipose tissue (IMAT) and its indices were used to evaluate myosteatosis. Muscle strength was evaluated using hand grip strength, whereas physical performance was evaluated through 4-m gait speed, a 30-s sit-to-stand test and 2-min walking test. RESULTS: Of the 1440 patients, 51.5% were women, and 37.2% had diabetes. With aging, the LAMA index gradually increased, and the NAMA index gradually decreased in both men and women (p for trend <&#x2009;0.001). The NAMA index was positively associated, whereas the LAMA and IMAT indices were negatively associated with muscle strength and physical performance after adjusting for age and sex. Higher tertiles of the NAMA index were consistently associated with improved physical performance across all appendicular skeletal muscle tertiles. The relationship between the NAMA index or LAMA index and muscle strength and physical performance did not differ according to diabetic status. Regular exercise was associated with a higher NAMA index and a lower LAMA index in the non-diabetic group; however, no significant difference in muscle quality was observed in the diabetic group in relation to exercise. CONCLUSIONS: Reduced myosteatosis was positively associated with greater muscle strength and better physical performance in both men and women, regardless of muscle mass or diabetes status; improving myosteatosis may be a therapeutic target for the prevention of sarcopenia.

Humans↗
PubMed2006

Prevalence of prehypertension and hypertension in a Korean population: Korean National Health and Nutrition Survey 2001.

OBJECTIVE: The present study aimed to determine the prevalence of prehypertension and hypertension, and their association with the risk factors in a Korean population. DESIGN: The Korean Nation Health and Nutrition Survey 2001, a cross-sectional survey, was a nationally representative survey in which a stratified multistage sampling design was used. METHODS: Data from a comprehensive questionnaire, together with a physical examination and blood sample, were obtained from 6074 Korean adults (2620 men and 3454 women) aged > or = 20 years, and analysed. RESULTS: The estimated age-adjusted prevalence of hypertension and prehypertension was 22.9% (26.9% in men, 20.5% in women) and 31.6% (41.9% in men, 25.9% in women), respectively, in the Korean population according to Joint National Committee 7 criteria. Multivariate analysis revealed that age, gender, body mass index, fasting plasma glucose, total-cholesterol and alcohol consumption were significantly associated with hypertension. Overall, only 30.2% of the hypertensive individuals had been previously diagnosed. Furthermore, 22.9% of the hypertensive individuals were being treated with antihypertensive medication, but only 10.7% had their blood pressure adequately controlled. The rates of awareness, treatment and control were higher for the women than for the men, and these rates increased with age. CONCLUSION: Hypertension and prehypertension are common in Korea, and more than one-half of the hypertensive patients have not been diagnosed. These results place great emphasis on the urgent need for a public health program to improve the detection, prevention and treatment of hypertension and prehypertension.

Adult↗
PubMed2006

Effect of rosiglitazone on plasma adiponectin levels and arterial stiffness in subjects with prediabetes or non-diabetic metabolic syndrome.

OBJECTIVE: Thiazolidinediones have favorable influences on surrogate markers of atherosclerosis such as adiponectin, and arterial stiffness in diabetic patients. However, it is not well known whether these beneficial effects occur in subjects without diabetes, such as prediabetes or the non-diabetic metabolic syndrome (MetS). The present study was therefore designed to evaluate the effectiveness of the insulin-sensitizing agent rosiglitazone on circulating adipocytokine levels and brachial-ankle pulse wave velocity (baPWV) in non-diabetics. DESIGN AND METHODS: Ninety-nine subjects with prediabetes or non-diabetic MetS were randomly assigned to either rosiglitazone or an untreated control group (50 and 49 subjects respectively). The rosiglitazone group was treated daily for 12 weeks with 4 mg rosiglitazone. All subjects received a 75 g oral glucose test (OGTT) before and after treatment. In addition, baPWV, together with the levels of adiponectin, resistin, and high sensitivity C-reactive protein (hsCRP) were determined. RESULTS: Rosiglitazone treatment significantly increased circulating adiponectin levels (P < 0.001) relative to the control group (P = 0.21). Plasma resistin levels were unchanged in both the rosiglitazone-treated and -untreated groups, but baPWV and hsCRP were significantly decreased (P < 0.001 and P = 0.003 respectively) in the rosiglitazone group only. Multiple linear regression analysis showed that changes in plasma adiponectin and baPWV were significantly affected by rosiglitazone treatment. CONCLUSIONS: These data suggest that rosiglitazone may have an anti-atherogenic effect in subjects with prediabetes or non-diabetic MetS.

Adiponectin↗
PubMed2006

Delayed puberty due to pituitary stalk dysgenesis and ectopic neurohypophysis.

Hypopituitarism is not a common cause of delayed puberty. A 22 year old man was referred to our clinic because of the absence of the development of secondary sexual characteristics. The patient had no complaints of physical discomfort. Random serum testosterone and luteinizing hormone level were obtained and found to be low. The combined pituitary function stimulation test revealed a partial hypopituitarism. A pituitary magnetic resonance imaging (MRI) was obtained and showed decreased pituitary stalk enhancement and ectopic neurohypophysis. Therefore, we conclude that the delayed puberty was a result of hypopituitarism due to pituitary stalk dysgenesis and ectopic neurohypophysis. The patient was started on hormone replacement therapy and gradually developed secondary sexual characteristics.

Adult↗
PubMed2005

The influence of illusory motion on line bisection performance in normal subjects.

The present study examines whether illusory movement (IM) of a horizontal line, induced by a moving background (MB), influences line-bisection performance in normal subjects. The first experiment attempted to identify the speeds of MB that induce IM. We found that when speed is increased from 1.53 degrees to 13.3 degrees/sec, IM increases, but that with further speed increases, IM decreases. Leftward MB induces rightward IM, and vice versa. In the second experiment, we had subjects bisect lines at MB speeds that had been shown to induce IM in the first experiment. We found that leftward MB induced a rightward bias, and vice versa. We also found that there was a relationship between the magnitude of IM and the degree of bias. In the third experiment, by making the target line larger than the MB, we made the conditions where IM was presumably absent. Unlike the results of bisection performed with IM, subjects showed a bias in the direction of the MB. Overall, these experiments demonstrated that the perception of motion induces subjects to attend in the direction of movement.

Adult↗
PubMed2005

Relation between elevated serum alanine aminotransferase and metabolic syndrome in Korean adolescents.

BACKGROUND: Concern is growing about nonalcoholic fatty liver disease, not only because it is a common liver disorder but also because it is one of the leading causes of chronic liver disease. Unexplained elevations in aminotransferase concentrations have been strongly associated with adiposity and thus may represent nonalcoholic fatty liver disease. OBJECTIVE: We investigated the relation between nonviral or nonalcoholic elevations in alanine aminotransferase (ALT) and the metabolic syndrome in Korean adolescents. DESIGN: Data were obtained from 1594 subjects aged 10-19 y from the Korean National Health and Nutrition Examination Survey 1998, a cross-sectional health survey of a nationally representative sample of noninstitutionalized civilian South Koreans. Body mass index, waist circumference, blood pressure, fasting glucose, lipid profiles, and serum ALT were measured. RESULTS: The prevalence of elevated ALT (> 40 U/L) was 3.6% in boys and 2.8% in girls. The prevalence of metabolic syndrome was 3.3% in both boys and girls. The components of the metabolic syndrome were significantly worse in the group with elevated ALT concentrations than in the group with normal ALT concentrations. The odds ratios (95% CIs) for elevated ALT were 6.6 (3.7, 11.8), 2.3 (1.2, 4.6), and 3.0 (1.6, 5.8) in the adolescents with abdominal obesity, high triacylglycerol concentrations, and low HDL-cholesterol concentrations, respectively. The odds ratios for elevated ALT were 1.5 (0.7, 3.1), 2.6 (1.1, 6.2), and 6.2 (2.3, 16.8) in the adolescents with 1, 2, and > or = 3 risk factors (metabolic syndrome), respectively. CONCLUSION: The metabolic syndrome was strongly associated with elevated ALT concentrations in Korean adolescents, and this association existed in a graded fashion across the number of metabolic components.

Abdominal Fat↗
PubMed2005

Vascular endothelial growth factor (VEGF) and soluble VEGF receptor FLT-1 in diabetic nephropathy.

BACKGROUND: Vascular endothelial growth factor (VEGF) and its receptors have been implicated in the pathogenesis of diabetic nephropathy. The objective of this study was to determine whether alterations of the plasma and urinary VEGF and sFLT-1 levels were related to the stages and risk factors of diabetic nephropathy. In addition, we also examined the regulation of the VEGF/sFLT-1 expression by various stimuli in cultured human proximal tubule cells (HPTC). METHODS: A total of 107 type 2 diabetic patients and 47 healthy control subjects were studied. The expression and protein levels of VEGF and sFLT-1 were measured by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). RESULTS: The urinary VEGF and sFLT-1 excretions were significantly increased in the microalbuminuric and proteinuric diabetic patients. The urinary VEGF levels were positively correlated with the urinary albumin to creatinine ratio (ACR), urinary sFLT-1 levels, and negatively correlated with creatinine clearance. The urinary sFLT-1 levels also showed a positive relationship with the urinary ACR. In cultured HPTC, high glucose stimuli rapidly up-regulated VEGF synthesis without having any effect on sFLT-1 synthesis. Interestingly, angiotensin II (Ang II) induced a dose-dependent increase in the synthesis of both VEGF and sFLT-1, which was significantly blocked by losartan. CONCLUSION: The urinary excretion of VEGF and sFLT-1 increased at a relatively early stage in diabetic nephropathy associated with urinary albumin excretion. A marked increase in both VEGF/sFLT-1 synthesis in response to Ang II was observed in HPTC, which was different from the response to glucose stimuli. These findings may imply that VEGF and sFLT-1 can actively take part in the pathogenesis of diabetic nephropathy.

Adult↗
PubMed2005

The prevalence of metabolic syndrome in patients with gout: a multicenter study.

It has been suggested that hyperuricemia and possibly gout are associated with the metabolic syndrome, but there have been no direct studies. This study was undertaken to obtain the prevalence of the metabolic syndrome in patients with gout and to compare it with those from the general population studies. This was a 4-institutional case-historical control study composed of 168 patients with gout. We assessed the prevalence of metabolic syndrome according to the ATP III criteria and compared the prevalence with that of the historical controls. To elucidate the factors in gout that were associated with metabolic syndrome, a multivariate analysis was done. The age-adjusted prevalence of metabolic syndrome in gout patients was 43.6%, which was significantly higher than that of the Korean control population (5.2%) from the previous studies. Patients with gout had more components of metabolic syndrome than did the controls. Body mass index (BMI, OR = 1.357 (95%CI 1.111-1.657)) and high density lipoprotein (HDL, OR = 0.774 (95%CI 0.705-0.850)) were the variables most significantly associated with the occurrence of metabolic syndrome in gout, but alcohol consumption did not show such associations. Gout is associated with the metabolic syndrome, and furthermore, obesity and dyslipidemia were the factors most associated with the syndrome in these patients.

Adult↗
PubMed2005

Clinical study of adrenal incidentaloma in Korea.

BACKGROUND: This study was designed to evaluate the clinical, endocrinological and histological characteristics of adrenal incidentalomas. METHODS: Eighty patients (41, males; 38, females; age range 17-80 years) who were diagnosed with adrenal incidentaloma at Korea University Hospital from 1992 to 2003 were studied retrospectively. RESULTS: Endocrinological investigation revealed 16 pheochromocytomas (20%), nine Cushing's syndromes (11%), eight primary aldosteronism (10%) and 46 non-functioning tumors (58%). Forty-four patients received operations, and biopsies were performed on two patients. Pathologic examination revealed 16 adrenocortical adenomas (20%), five carcinomas (6%), 13 pheochromocytomas (16%), three metastatic cancers (4%), and other tumors (10%). The diameter of the carcinomas (mean: 10.8 cm, range: 5-19 cm) were significantly larger than the diameter of benign adenomas (mean: 2.84 cm, range: 1-6 cm) (p=0.002). According to the receiver operating charactenstic (ROC) curve analysis, the cut-off value of tumor size for discriminate malignant tumor was 4.75 cm (sensitivity 90%, specificity 58%). Twenty-four patients with non-functioning tumors were followed up for a period of 3 to 72 months. During the follow up period, two patients showed an increase in tumor size of more than 1 cm, and one patient developed Cushing's syndrome. Changes in mass size and function were observed only between 10 and 26 months after the initial diagnosis. CONCLUSIONS: These data show that an endocrine evaluation should be performed in all adrenal incidentalomas, and an adrenalectomy is recommended for tumors 5 cm or greater or tumors with adrenocortical hyperfunction. In addition, these tumors should be monitored for changes in mass size and function for a follow up period of approximately 26 months.

Adolescent↗
PubMed2004

Reduced expression of peroxisome proliferator-activated receptor-alpha may have an important role in the development of non-alcoholic fatty liver disease.

BACKGROUND: Although the pathogenesis of non-alcoholic fatty liver disease (NAFLD) remains poorly understood, metabolic syndrome associated with insulin resistance is the most reproducible factor in the development of NAFLD. Fat accumulation in hepatocytes results from an imbalance in the input, output and oxidation of fatty acid. Peroxisomes contain a battery of fatty acid oxidizing enzymes, the first of which, acyl-CoA oxidase (AOX), initiates the beta-oxidation spiral. One of the mammalian peroxisome proliferator-activated receptors (PPAR), PPAR-alpha, regulates the transcriptional expression of the enzymes involved in fatty acid beta-oxidation. The aim of the present study was to define the role of PPAR-alpha and AOX in the development of NAFLD using the Otsuka Long-Evans Tokushima fatty (OLETF) rat model. METHODS: Liver tissue from OLETF (n = 12) and control (n = 10) rats 12, 28, and 40 weeks old were processed for histopathological and western blot analysis. The messenger RNA of PPAR-alpha and AOX were quantified by real-time RT-PCR. RESULTS: At 40 weeks old, the histological analysis of the OLETF rat liver had steatosis (approximately 66%) and mild inflammation, which were comparable to those in NAFLD. Histological changes were unremarkable in 12 week and 28 week rats. In 12 week OLETF rats, the mRNA of AOX was 63% of the control. Expression of PPAR-alpha mRNA was also reduced to 3% that of the control. Along with the changes of mRNA, the protein expression of PPAR-alpha was also significantly reduced to 17% that of the control. In 28 week and 40 week animals, PPAR-alpha protein expression gradually increased to 75% and 78% that of the control. Expression of PPAR-alpha mRNA was also increased by up to 26% and 110% of the control. AOX, regulated by PPAR-alpha, also increased to 149% and 120% of the control. CONCLUSION: Reduced expression of PPAR-alpha and AOX was observed even before definite steatosis had developed. The alteration of peroxisomal fatty acid metabolism may have an important role in the development of NAFLD.

Acyl-CoA Oxidase↗