ABSTRACT
Like other substrates, plasma glucose is in a dynamic state of constant turnover (i.e., rates of glucose appearance [Ra glucose] into and disappearance [Rd glucose] from the plasma) while staying within a narrow range of normal concentrations, a physiological priority. Persistent imbalance of glucose turnover leads to elevations (i.e., hyperglycemia, Ra>Rd) or falls (i.e., hypoglycemia, Ra
ABSTRACT
Like other substrates, plasma glucose is in a dynamic state of constant turnover (i.e., rates of glucose appearance [Ra glucose] into and disappearance [Rd glucose] from the plasma) while staying within a narrow range of normal concentrations, a physiological priority. Persistent imbalance of glucose turnover leads to elevations (i.e., hyperglycemia, Ra>Rd) or falls (i.e., hypoglycemia, Ra
ABSTRACT
The human body is in a constant state of turnover, that is, being synthesized, broken down and/or converted to different compounds. The dynamic nature of in vivo kinetics of human metabolism at rest and in stressed conditions such as exercise and pathophysiological conditions such as diabetes and cancer can be quantitatively assessed with stable, nonradioactive isotope tracers in conjunction with gas or liquid chromatography mass spectrometry and modeling. Although measurements of metabolite concentrations have been useful as general indicators of one's health status, critical information on in vivo kinetics of metabolites such as rates of production, appearance or disappearance of metabolites are not provided. Over the past decades, stable, nonradioactive isotope tracers have been used to provide information on dynamics of specific metabolites. Stable isotope tracers can be used in conjunction with molecular and cellular biology tools, thereby providing an in-depth dynamic assessment of metabolic changes, as well as simultaneous investigation of the molecular basis for the observed kinetic responses. In this review, we will introduce basic principles of stable isotope methodology for tracing in vivo kinetics of human or animal metabolism with examples of quantifying certain aspects of in vivo kinetics of carbohydrate, lipid and protein metabolism.
Subject(s)
Animals , Humans , Chromatography, Liquid , Human Body , Kinetics , Mass Spectrometry , MetabolismABSTRACT
The dramatic increase in the prevalence of obesity and its accompanying comorbidities are major health concerns in Korea. Obesity is defined as a body mass index > or =25 kg/m2 in Korea. Current estimates are that 32.8% of adults are obese: 36.1% of men and 29.7% of women. The prevalence of being overweight and obese in national surveys is increasing steadily. Early detection and the proper management of obesity are urgently needed. Weight loss of 5% to 10% is the standard goal. In obese patients, control of cardiovascular risk factors deserves the same emphasis as weight-loss therapy. Since obesity is multifactorial, proper care of obesity requires a coordinated multidisciplinary treatment team, as a single intervention is unlikely to modify the incidence or natural history of obesity.
Subject(s)
Adult , Female , Humans , Male , Body Mass Index , Comorbidity , Incidence , Korea , Natural History , Obesity , Overweight , Prevalence , Risk Factors , Weight LossABSTRACT
The prevailing model of osteology is that bones constantly undergo a remodeling process, and that the differentiation and functions of osteoblasts are partially regulated by leptin through different central hypothalamic pathways. The finding that bone remodeling is regulated by leptin suggested possible endocrinal effects of bones on energy metabolism. Recently, a reciprocal relationship between bones and energy metabolism was determined whereby leptin influences osteoblast functions and, in turn, the osteoblast-derived protein osteocalcin influences energy metabolism. The metabolic effects of bones are caused by the release of osteocalcin into the circulation in an uncarboxylated form due to incomplete gamma-carboxylation. In this regard, the Esp gene encoding osteotesticular protein tyrosine phosphatase is particularly interesting because it may regulate gamma-carboxylation of osteocalcin. Novel metabolic roles of osteocalcin have been identified, including increased insulin secretion and sensitivity, increased energy expenditure, fat mass reduction, and mitochondrial proliferation and functional enhancement. To date, only a positive correlation between osteocalcin and energy metabolism in humans has been detected, leaving causal effects unresolved. Further research topics include: identification of the osteocalcin receptor; the nature of osteocalcin regulation in other pathways regulating metabolism; crosstalk between nutrition, osteocalcin, and energy metabolism; and potential applications in the treatment of metabolic diseases.
Subject(s)
Humans , Bone Remodeling/physiology , Bone and Bones/metabolism , Energy Metabolism , Leptin/metabolism , Osteocalcin/geneticsABSTRACT
BACKGROUND: The purpose of the current study was to investigate the association of obesity level, physical fitness level, hemoglobin A1c (HbA1c) level and metabolic syndrome (MetS) risk factors among Korean adults. METHODS: A total of 557 adults (272 males and 285 females) who underwent medical check-up at local hospital were recruited. In addition to regular health check-up, cardiopulmonary fitness, muscular endurance were measured and their association were analyzed. RESULTS: The prevalence of MetS was 31.7% for males and 23.7% for females. Females with the higher muscular endurance had lower waist circumference, triglyceride level, and HbA1c level than those with the lower muscular endurance. Males with the higher level of cardiopulmonary fitness had lower diastolic blood pressure, lower high-sensitivity C-reactive protein level and higher high density lipoprotein cholesterol level than males with the lower level of cardiopulmonary fitness. Females with the higher level of cardiopulmonary fitness had lower body weight, body mass index, systolic blood pressure, and fasting blood glucose level than females with the lower level of cardiopulmonary fitness. Participants with the higher level of adiposity and the lower level of physical fitness were 5.26 times (95% confidence interval [CI], 2.19 to 12.62), 5.71 times (95% CI, 2.23 to 14.60) more likely to have MetS, respectively, in male and female compared to participants who were neither obese nor have the lower level of fitness. CONCLUSION: This study suggests that maintaining a healthy body weight as well as a certain level of fitness is important for the prevention of MetS.
Subject(s)
Adult , Female , Humans , Male , Adiposity , Blood Glucose , Blood Pressure , Body Mass Index , Body Weight , C-Reactive Protein , Cholesterol , Cholesterol, HDL , Fasting , Hemoglobins , Hypotension , Lipoproteins , Obesity , Physical Fitness , Prevalence , Risk Factors , Waist CircumferenceABSTRACT
BACKGROUND AND OBJECTIVES: Obesity is a chronic disease that requires good eating habits and an active life style. Obesity may start in childhood and continue until adulthood. Severely obese children have complications such as diabetes, hypercholesterolemia, hypertension and atherosclerosis. The goal of this study was to determine the effects of exercise programs on anthropometric, metabolic, and cardiovascular parameters in obese children. SUBJECTS AND METHODS: Fifty four obese children were included. Anthropometric data such as blood pressures, body mass index (BMI) and obesity index (OI) were measured. Blood glucose, total cholesterol, triglycerides, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), aspartate aminotransferase (AST), alanine aminotransferase (ALT), high sensitive-CRP (hs-CRP), brachial-ankle pulse wave velocity (BaPWV) and ankle brachial index (ABI) were measured. Physical fitness measurements were done. Obese children were divided into three groups: an aerobic exercise group (n=16), a combined exercise group (n=20), and a control group (n=18). Obese children exercised in each program for 10 weeks while those in the control group maintained their former lifestyle. After 10 weeks, anthropometric data and cardiovascular parameters were compared with the data obtained before the exercise program. RESULTS: LDL-C, waist circumference, and systolic blood pressure decreased significantly in the aerobic exercise group compared to the control group (p<0.05). Waist circumference and systolic blood pressure decreased significantly in the combined exercise group compared to controls (p<0.05). Physical fitness level increased significantly after the exercise programs (p<0.05 vs. control). PWV did not show a significant change after exercise. CONCLUSION: A short-term exercise program can play an important role in decreasing BMI, blood pressure, waist circumference, LDL-C and in improving physical fitness. Future investigations are now necessary to clarify the effectiveness of exercise on various parameters.
Subject(s)
Child , Humans , Alanine Transaminase , Ankle Brachial Index , Aspartate Aminotransferases , Atherosclerosis , Blood Glucose , Blood Pressure , Body Mass Index , Cardiovascular Diseases , Cholesterol , Chronic Disease , Eating , Exercise , Hypercholesterolemia , Hypertension , Life Style , Obesity , Physical Fitness , Pulse Wave Analysis , Triglycerides , Waist CircumferenceABSTRACT
No abstract available.