| Nam-Seok Joo | 8 Articles |
Background
Serum thyroid-stimulating hormone (TSH) levels change during body weight reduction. However, the changes that occur during short-term body weight control interventions remain controversial. Thus, this study aimed to evaluate the changes in TSH levels according to body fat reduction. Methods We performed a 3-month intervention study involving partial meal replacement. Forty-nine participants completed the study. Correlations between changes in TSH levels and other body composition parameters were determined. The subjects were divided into two groups according to their body fat reduction (>1 kg, n=20; <1 kg, n=29). The changes in metabolic parameters, including TSH levels, were compared. For significant values, a multivariate analysis was performed after adjustment to evaluate the relationship between TSH changes and body fat reduction. Results The 3-month intervention caused favorable changes in body proportions and metabolic parameters. TSH levels changed significantly only after changes in total body fat, showing a partial correlation. Changes in TSH levels were significantly different between groups (P=0.014). Moreover, the change in TSH levels was significantly different after adjustment (P=0.012). Conclusion A body fat reduction, especially >1 kg, can reduce serum TSH concentrations in subjects with metabolic syndrome after short-term body weight intervention.
Identifying and preventing modifiable risk factors for cardiovascular disease is very important. Vascular calcification has been studied clinically as an asymptomatic preclinical marker of atherosclerosis and a risk factor for cardio-cerebrovascular disease. It is known that higher homocysteine levels are associated with calcified plaques and the higher the homocysteine level, the higher the prevalence and progression of vascular calcification. Homocysteine is a byproduct of methionine metabolism and is generally maintained at a physiological level. Moreover, it may increase if the patient has a genetic deficiency of metabolic enzymes, nutritional deficiencies of related cofactors (vitamins), chronic diseases, or a poor lifestyle. Homocysteine is an oxidative stress factor that can lead to calcified plaques and trigger vascular inflammation. Hyperhomocysteinemia causes endothelial dysfunction, transdifferentiation of vascular smooth muscle cells, and the induction of apoptosis. As a result of transdifferentiation and cell apoptosis, hydroxyapatite accumulates in the walls of blood vessels. Several studies have reported on the mechanisms of multiple cellular signaling pathways that cause inflammation and calcification in blood vessels. Therefore, in this review, we take a closer look at understanding the clinical consequences of hyperhomocysteinemia and apply clinical approaches to reduce its prevalence.
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Background
Metabolic syndrome (MS) is a well-known risk factor of cardiovascular diseases that is focused on central obesity. Recent studies have reported the association between pericardial adipose tissue (PAT) volume and MS. However, no studies have demonstrated the cutoff PAT volume that represents the best association with MS. Methods The data of 374 subjects were analyzed cross-sectionally to compare PAT, measured on coronary multidetector computed tomography, and various metabolic parameters according to MS. After PAT volumes were divided into tertiles, various metabolic parameters were compared among tertiles; furthermore, the odds ratio for developing MS was calculated. Finally, we demonstrated the cutoff PAT volume that represented the best association with MS by using the receiver-operating characteristic curve. Results We found that 27.5% of the subjects had MS, and the mean PAT volume was 123.9 cm3 . PAT showed a significant positive correlation with body mass index, waist circumference, and levels of glucose, triglyceride, high-sensitivity C-reactive protein, uric acid, and homocysteine, but a negative correlation with high-density lipoprotein cholesterol. Furthermore, after dividing into tertiles, PAT volume was also significantly associated with various metabolic parameters. The odds ratio for having MS was 4.19 (95% confidence interval, 2.27–7.74) in the top tertile of PAT volumes after adjusting for age, sex, and smoking. The cutoff PAT volume that represented the best association with MS was 142.2 cm3 . Conclusion PAT was significantly associated with MS and various metabolic parameters. The cutoff PAT volume of 142.2 cm3 showed the best association with MS.
Abnormal serum gamma-glutamyltransferase (γ-GT) may be an early and sensitive marker for oxidative stress. This study was performed to evaluate the association between serum heavy metals and γ-GT concentration. This study is a cross-sectional analysis based on data from Korean National Health and Nutrition Examination Survey (V-1, 2, 2010, 2011) regarding serum heavy metal concentrations (lead, mercury, and cadmium) as well as serum γ-GT. Serum heavy metals were categorized into tertiles, and serum γ-GT concentration was compared using an analysis of covariance test after relevant variable adjustments. In addition, we evaluated the odds ratio (OR) of having the highest tertile of serum γ-GT in each heavy metal tertile using logistic regression. The mean serum lead, mercury, and cadmium concentrations were 2.67, 5.08, and 1.02 µg/dL in men and 1.95, 3.60, and 1.21 µg/dL in women, respectively. Partial correlation showed a significant positive relation between each heavy metal and serum γ-GT concentration. Comparing serum γ-GT concentration by the tertile of each heavy metal, serum γ-GT concentration showed a significant increase as the tertiles of serum mercury and cadmium in men and that of serum mercury in women increased, but not with lead. The OR of having the highest tertile of serum γ-GT was significant for cadmium in men (OR, 4.02; 95% confidence interval [CI], 2.54 to 6.35) and mercury in women (OR, 2.00; 95% CI, 1.29 to 3.10) in the top tertile of each heavy metal. Higher serum heavy metal concentration may be related with higher serum γ-GT concentration. In particular, serum cadmium in men and mercury in women showed significant correlation with serum γ-GT concentration. Citations Citations to this article as recorded by
The glomerular filtration rate (GFR) decreases with age, while parathyroid hormone (PTH) increases. There are a few reports only on the relationship between GFR and PTH under the category of serum 25-hydroxyvitamin D (25[OH]D) concentration. Using the Korea National Health and Nutrition Examination Survey (KNHANES) data, a cross-sectional study was conducted on the association between serum 25(OH)D concentration, GFR and PTH in Korean adults aged 50 years or older. Serum PTH concentration was compared to the tertiles of GFR after adjustment for relevant variables. In addition, the serum PTH concentration was compared with the GFR under the category of serum 25(OH) D concentration (<20, 20-30, >30 ng/mL). The mean estimated GFR (eGFR) was 74.8 mL/min in men and 73.1 mL/min in women. The mean PTH and 25(OH) D was 66.8 pg/mL, 20.5 ng/mL in men and 69.0 pg/mL, 18.2 ng/mL in women. The serum PTH concentration showed a significant negative correlation with the serum 25(OH) D and eGFR in both genders. The serum PTH concentration significantly increased at the lower tertile of eGFR in male adults In addition, a decrease of serum PTH concentration was marked in the vitamin D sufficient male adults (>30 ng/mL). This present study demonstrated that serum PTH concentration showed negative correlation with eGFR, however, serum PTH increase may be minimized by maintaining proper serum 25(OH)D concentrations under similar eGFR status in Korean adults aged 50 and above. Citations Citations to this article as recorded by
Vitamin D is an important factor in human health. Yet, vitamin D deficiency is very common. We aimed to confirm serum 25-hydroxyvitamin D (25OHD) concentration change after sunlight exposure and to elucidate the relationship between the amount of sunlight exposure and serum 25OHD level change by ambulatory lux meter and sunlight exposure questionnaire. Twenty healthy young women were enrolled. They were educated to obtain 20 minutes of sunlight exposure during weekdays from October to November, 2010, during which they were to wear an ambulatory lux meter on an arm. All subjects completed a one-week recall sunlight exposure questionnaire at the end of the study. Before and after sunlight exposure, serum 25OHD level was measured. Mean pre-exposure serum 25OHD concentration was 11.01 ng/mL. The mean change of pre- and post-exposure 25OHD level was -0.62 ng/mL, but it was not statistically significant. The mean personal sunlight exposure recorded by ambulatory lux meter, 292.6 lux/s, showed no significant relationship with average change of 25OHD and average weekly sunlight exposure score, 11.9, calculated by the sunlight exposure questionnaire. However, the mean change of serum 25OHD level and weekly sunlight exposure score showed significant negative correlation (r = -0.469, P = 0.037). Change of serum 25OHD concentration after four weeks of sunlight exposure was not statistically significant in women with vitamin D deficiency. However, serum 25OHD concentration change was significantly negatively correlated with the sunlight exposure score by the questionnaire. Citations Citations to this article as recorded by
Cigarette smoking causes cardiovascular disease and activates markers of endothelial dysfunction or injury. We investigated the nailfold capillary blood velocity (NCV) in cigarette smokers compared to non-smokers. Forty-eight men (eighteen non-smokers and thirty smokers) were recruited. We measured NCV using nailfold capillary microscopy and exhaled carbon monoxide (ECO) concentration three times (before smoking; NCV0min and ECO0min, and after smoking; NCV5min, ECO5min, NCV30min, and ECO30min), in a condition of fasting in the case of smokers. In non-smokers, the same measurements were taken without smoking. Additionally, personal cigarette smoking and alcohol drinking history were acquired by a self-administrated questionnaire. Mean age, waist circumference, ECO0min, ECO5min, and ECO30min was higher and NCV5min and NCV30min were significantly lower in smokers compared to non-smokers. Total smoking years were negatively correlated with NCV5min. Average pack of the daily smoking, total pack-years, as well as total smoking years were also negatively correlated with NCV30min by regression analysis. After adjustment of significantly different variables, NCV30min was significantly lower in smokers. In the subgroup analysis, the interleukin-6 level was significantly increased in subjects with a long period of cigarette smoking compared with non-smokers. Reduction of NCV in smokers is associated with personal smoking history, not with body composition or certain oxidative stress markers. Citations Citations to this article as recorded by
Whole body vibration (WBV) confers a continuous vibration stimuli to the body. While some reports have described the effects of WBV on bone mineral density, muscle mass, muscle power, study of WBV effects on body composition in postmenopausal women is rare. The aim of this pilot study was to examine the effect of WBV on the changes of body weight and body composition in postmenopausal women. Fifteen postmenopausal healthy and obese women who were on staff of one university hospital staff located in Suwon, Korea were voluntarily recruited. Inclusion criteria were age over 50 years, and body mass index (BMI) ≥25 kg/m2. WBV group training was performed in 10 minute sessions twice weekly for 8 weeks. Before and after training, anthropometric measurements and body composition analysis were performed. Weight (-1.18 ± 1.61 kg), BMI (-0.49 ± 0.66 kg/m2), waist circumference (-2.34 ± 2.48 cm) and muscle mass (-0.54 ± 0.59 kg) decreased significantly the 8 week intervention. Decrease of muscle mass was correlated with weight (r = 0.621, P = 0.013), BMI (r = 0.596, P = 0.019) and percent body fat (r = -0.518, P = 0.048). Linear regression analysis revealed that the changes of muscle mass had negative relationship with percent body fat change and a positive relationship with body weight changes. WBV might display a weak but positive effect on body weight and waist circumference reduction in healthy postmenopausal obese women. However, attention must be given to avoid a decrease of muscle mass. Citations Citations to this article as recorded by
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