Skeletal muscle is the largest organ of the body in non-obese individuals and is now considered to be an endocrine organ. Hormones (myokines) secreted by skeletal muscle mediate communications between muscle and liver, adipose tissue, brain, and other organs. Myokines affect muscle mass and myofiber switching, and have profound effects on glucose and lipid metabolism and inflammation, thus contributing to energy homeostasis and the pathogenesis of obesity, diabetes, and other diseases. In this review, we summarize recent findings on the biology of myokines and provide an assessment of their potential as therapeutic targets.
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Subclinical hypothyroidism (SCH) is a common disorder that is characterized by elevated thyroid-stimulating hormone levels in conjunction with free thyroxine concentrations within the normal reference range. Thyroid hormones are known to affect the heart and vasculature and, as a result, the impact of SCH on the cardiovascular (CV) system has recently become an important topic of research. Strong evidence points to a link between SCH and CV risk factors such as alterations in blood pressure, lipid levels, and atherosclerosis. Additionally, accumulating evidence indicates that SCH is associated with metabolic syndrome and heart failure. The present review proposes that SCH may be a potentially modifiable risk factor of CV disease and mortality. However, large-scale clinical trials with appropriate power investigating the risks and benefits of SCH treatment are required to determine whether these benefits can be achieved with levothyroxine therapy.
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Recent advances in molecular diagnostics have led to significant insights into the genetic basis of thyroid tumorigenesis. Among the mutations commonly seen in thyroid cancers, the vast majority are associated with the mitogen-activated protein kinase pathway. B-Raf proto-oncogene (
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The prevalence of diabetes is increasing globally, particularly in Asia. According to the 2013 Diabetes Atlas, an estimated 366 million people are affected by diabetes worldwide; 36% of those affected live in the Western Pacific region, with a significant proportion in East Asia. The reasons for this marked increase in the prevalence of diabetes can be extrapolated from several distinct features of the Asian region. First, the two most populated countries, China and India, are located in Asia. Second, Asians have experienced extremely rapid economic growth, including rapid changes in dietary patterns, during the past decades. As a result, Asians tend to have more visceral fat within the same body mass index range compared with Westerners. In addition, increased insulin resistance relative to reduced insulin secretory function is another important feature of Asian individuals with diabetes. Young age of disease onset is also a distinctive characteristic of these patients. Moreover, changing dietary patterns, such as increased consumption of white rice and processed red meat, contributes to the deteriorated lifestyle of this region. Recent studies suggest a distinctive responsiveness to novel anti-diabetic agents in Asia; however, further research and efforts to reverse the increasing prevalence of diabetes are needed worldwide.
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SGLT2 Inhibitors as Add-On Therapy to Metformin for People with Type 2 Diabetes: A Review of Placebo-Controlled Trials in Asian versus Non-Asian Patients
The present study evaluated the efficacy of a combination of ibandronate and cholecalciferol on the restoration of the levels of 25-hydroxyvitamin D (25[OH]D) and various bone markers in postmenopausal women with osteoporosis.
This was a randomized, double-blind, active-controlled, prospective 16-week clinical trial conducted in 20 different hospitals. A total of 201 postmenopausal women with osteoporosis were assigned randomly to one of two groups: the IBN group, which received a once-monthly pill containing 150 mg ibandronate (
After 16 weeks of treatment, the mean serum levels of 25(OH)D significantly increased from 21.0 to 25.3 ng/mL in the IBN+ group but significantly decreased from 20.6 to 17.4 ng/mL in the IBN group. Additionally, both groups exhibited significant increases in mean serum levels of PTH but significant decreases in serum levels of bone-specific alkaline phosphatase and C-telopeptide of type 1 collagen (CTX) at 16 weeks; no significant differences were observed between the groups. However, in subjects with a vitamin D deficiency, IBN+ treatment resulted in a significant decrease in serum CTX levels compared with IBN treatment.
The present findings demonstrate that a once-monthly pill containing ibandronate and cholecalciferol may be useful for the amelioration of vitamin D deficiency in patients with postmenopausal osteoporosis. Moreover, this treatment combination effectively decreased serum levels of resorption markers, especially in subjects with a vitamin D deficiency, over the 16-week treatment period.
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In this cross-sectional study, 84
The mean age of participants was 54±10 years, and 44% were men. Mean HpSAg levels and PGI/PGII ratio were 0.24±0.23 µg/mL and 9.9±9.0, respectively. Higher HpSAg as well as lower PGI/PGII was correlated with higher anthropometric measures and LAP. A significant negative correlation between PGI/PGII ratio and blood pressure (
Higher
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The incidence and prevalence of overt hypothyroidism have been reported to be 2 to 4/1,000 population/year and 8 to 13/1,000 population, respectively, in foreign countries. As there has been no nationwide survey to obtain data in Korea, the present study investigated the incidence and prevalence of overt hypothyroidism in Korea using claims data provided by the Health Insurance Review and Assessment Service. The proportions of causative diseases for hypothyroidism were also analyzed.
This study was retrospectively performed with 541,969 Korean patients (92,832 men and 449,137 women), with overt hypothyroidism, treated with thyroid hormone between 2008 and 2012.
The incidence of overt hypothyroidism in Korea was 2.26/1,000 population/year (0.78 in men and 3.72 in women), and the prevalence was 14.28/1,000 population (4.40 in men and 24.03 in women). When patients with thyroid cancer were excluded, the incidence was 1.56/1,000 population/year (0.54 in men and 2.57 in women). The incidence increased with age, with peaks in and after the late 60s in men and in the early 50s in women. The prevalence peaked in the early 70s in men and in the late 50s in women.
This is a report of the first nationwide investigation of the incidence and prevalence of overt hypothyroidism in Korea, although it is limited to patients treated with thyroid hormone.
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Measurement of the plasma adrenocorticotropic hormone (ACTH) level has been recommended as the first diagnostic test for differentiating between ACTH-independent Cushing syndrome (CS) and ACTH-dependent CS. When plasma ACTH values are inconclusive, a differential diagnosis of CS can be made based upon measurement of the serum dehydroepiandrosterone sulfate (DHEA-S) level and results of the high-dose dexamethasone suppression test (HDST). The aim of this study was to assess the utility of plasma ACTH to differentiate adrenal CS from Cushing' disease (CD) and compare it with that of the HDST results and serum DHEA-S level.
We performed a retrospective, multicenter study from January 2000 to May 2012 involving 92 patients with endogenous CS. The levels of plasma ACTH, serum cortisol, 24-hour urine free cortisol (UFC) after the HDST, and serum DHEA-S were measured.
Fifty-seven patients had adrenal CS and 35 patients had CD. The area under the curve of plasma ACTH, serum DHEA-S, percentage suppression of serum cortisol, and UFC after HDST were 0.954, 0.841, 0.950, and 0.997, respectively (all
Significant overlap in plasma ACTH levels was seen between patients with adrenal CS and those with CD. The HDST may be useful in differentiating between these forms of the disease, especially when the plasma ACTH level alone is not conclusive.
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Obesity is associated with aggressive pathological features and poor clinical outcomes in breast and prostate cancers. In papillary thyroid carcinoma (PTC), these relationships remain still controversial. This study aimed to evaluate the associations between body mass index (BMI) and the clinical outcomes of patients with PTC.
This retrospective study included 1,189 patients who underwent total thyroidectomy for PTCs equal to or larger than 1 cm in size. Clinical outcomes were evaluated and compared based on the BMI quartiles.
There were no significant associations between BMI quartiles and primary tumor size, extrathyroidal invasion, cervical lymph node metastasis, or distant metastasis. However, an increase in mean age was associated with an increased BMI (
In the present study, BMI was not associated with the aggressive clinicopathological features or recurrence-free survivals in patients with PTC.
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This study investigated the association between the frequency of growth hormone receptor (GHR) exon 3 polymorphism (exon 3 deletion; d3-GHR) and metabolic factors in patients with acromegaly in Korea.
DNA was extracted from the peripheral blood of 30 unrelated patients with acromegaly. GHR genotypes were evaluated by polymerase chain reaction and correlated with demographic data and laboratory parameters.
No patient had the d3/d3 genotype, while four (13.3%) had the d3/fl genotype, and 26 (86.7%) had the fl/fl genotype. Body mass index (BMI) in patients with the d3/fl genotype was significantly higher than in those with the fl/fl genotype (
The d3-GHR polymorphism may be associated with high BMI but not with other demographic characteristics or laboratory parameters.
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Thyroid hormones can influence energy metabolism and insulin sensitivity via their interaction with adipocytokines and gut hormones. The aims of this study were to evaluate differences in serum ghrelin and leptin concentrations according to thyroid hormone levels, and to investigate the correlation of insulin resistance.
A total of 154 patients (57 hyperthyroid patients, 61 euthyroid patients, and 36 hypothyroid patients; mean age, 47.9 years) were enrolled. Serum leptin, ghrelin, and insulin levels were measured and insulin resistance was calculated using the formula of the homeostasis model assessment of insulin resistance (HOMA-IR).
There were no differences in mean concentrations of ghrelin or leptin among the three groups. There were no significant differences in insulin levels between the groups (
The present study found that serum ghrelin, leptin, and insulin levels didn't differ according to thyroid function conditions. Further studies with larger numbers of patients are required to establish a direct relationship between plasma ghrelin, leptin, and thyroid hormone.
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The significance of adiponectin levels in elderly individuals with prediabetes has yet to be determined. Thus, the present study was performed to evaluate the relationships between adiponectin levels and anthropometric variables, body composition parameters, insulin sensitivity, and lipid profiles in elderly prediabetic patients.
The present study included 120 subjects with prediabetes who were >65 years of age and were selected from among 1,993 subjects enrolled in the Korea Rural Genomic Cohort Study. All subjects underwent a 75 g oral glucose tolerance test and tests for measurement of insulin sensitivity. All diagnoses of prediabetes satisfied the criteria of the American Diabetes Association.
Plasma adiponectin levels were lower in elderly prediabetic subjects than elderly subjects with normal glucose tolerance (
The present findings demonstrated that the major factors correlated with adiponectin levels in elderly prediabetic subjects were BMI, WC, waist-to-hip ratio, visceral fat, visceral fat ratio, and 2-hour insulin levels.
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Metabolic syndrome (MetS), a cluster of multiple metabolic abnormalities, is one of the major public health challenges worldwide. The current study was conducted to evaluate the association between sugar-sweetened beverage (SSB) consumption and MetS and its components in Iranian adults.
This cross-sectional study was conducted among 5,852 men and women, aged 19 to 70 years, who participated in the fourth phase (2009 to 2011) of the Tehran Lipid and Glucose Study. Demographics, anthropometrics, biochemical measurements, and blood pressure (BP) were assessed and MetS was defined by National Cholesterol Education Program Adult Treatment Panel III definition. Frequency and quantity of SSB intakes including carbonated drinks and synthetic fruit juices were collected using a validated semiquantitative food frequency questionnaire.
Mean age of participants (43%, men) was 40.6±12.9 years. Significant positive associations between SSBs and waist circumference, triglyceride level, systolic and diastolic BP in the third and fourth quartile of SSBs were observed, after adjustment for all potential confounding variables. The odds of MetS in the third and fourth quartiles compared to the first quartile category of SSBs was 1.21 (95% confidence interval [CI], 1.01 to 1.45) and 1.30 (95% CI, 1.06 to 1.58), respectively (
Higher intake of SSBs was associated with the higher odds of MetS in adults. It is suggested that reducing consumption of SSBs could be a practical approach to prevent metabolic abnormalities.
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There are limited data about whether patients who receive initial treatment for differentiated thyroid cancer (DTC) gain or lose weight during long-term follow-up under thyroid stimulating hormone (TSH) suppression. This study was aimed to evaluate whether DTC patients under TSH suppression experience long-term weight gain after initial treatment. We also examined the impact of the radioactive iodine ablation therapy (RAIT) preparation method on changes of weight, comparing thyroid hormone withdrawal (THW) and recombinant human TSH (rhTSH).
We retrospectively reviewed 700 DTC patients who underwent a total thyroidectomy followed by either RAIT and levothyroxine (T4) replacement or T4 replacement alone. The control group included 350 age-matched patients with benign thyroid nodules followed during same period. Anthropometric data were measured at baseline, 1 to 2 years, and 3 to 4 years after thyroidectomy. Comparisons were made between weight and body mass index (BMI) at baseline and follow-up.
Significant gains in weight and BMI were observed 3 to 4 years after initial treatment for female DTC but not in male patients. These gains among female DTC patients were also significant compared to age-matched control. Women in the THW group gained a significant amount of weight and BMI compared to baseline, while there was no increase in weight or BMI in the rhTSH group. There were no changes in weight and BMI in men according to RAIT preparation methods.
Female DTC patients showed significant gains in weight and BMI during long-term follow-up after initial treatment. These changes were seen only in patients who underwent THW for RAIT.
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