Metabolism-related Parameters Research Articles

The Effects of a Hypocaloric Diet on Diet-Induced Thermogenesis and Blood Hormone Response in Healthy Male Adults: A Pilot Study.

Calorie restriction is a common strategy for weight loss and management. Consumption of food and nutrients stimulates diet-induced thermogenesis (DIT), as well as pancreatic and gastrointestinal hormone secretion that may regulate energy metabolism. Yet, little is known about the impact of hypocaloric diets on energy metabolism-related parameters. In this study, we assessed the effects of hypocaloric diets on hormonal variance in relation to DIT in healthy adults. Ten healthy male adults were enrolled in a randomized crossover study comprising three meal trials. Each subject was given a meal of 200 (extremely hypocaloric), 400 (moderately hypocaloric), or 800 kcal (normocaloric). Postprandial blood variables and energy expenditure were measured for 4 h (after the 200- and 400-kcal meals) or 6 h (after the 800-kcal meal). DIT and postprandial changes in blood pancreatic peptide and ghrelin were significantly smaller after the extremely or moderately hypocaloric diet than after the normocaloric diet but were similar between the hypocaloric diets. Postprandial blood insulin, amylin, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide type-1 (GLP-1) increased in a calorie-dependent manner. Thermogenic efficiency (DIT per energy intake) was negatively correlated with the maximum blood level (Cmax) (p=0.01) and incremental area under the curve (p=0.01) of the blood GIP response. Calorie restriction thus leads to hormonal responses and lower DIT in healthy adults. Extreme calorie restriction, however, led to greater thermogenic efficiency compared with moderate calorie restriction. The postprandial GIP response may be a good predictor of postprandial thermogenic efficiency.

Establishment of reference intervals of clinical chemistry analytes for the adult population in Saudi Arabia: a study conducted as a part of the IFCC global study on reference values.

This study is a part of the IFCC-global study to derive reference intervals (RIs) for 28 chemistry analytes in Saudis. Healthy individuals (n=826) aged ≥18 years were recruited using the global study protocol. All specimens were measured using an Architect analyzer. RIs were derived by both parametric and non-parametric methods for comparative purpose. The need for secondary exclusion of reference values based on latent abnormal values exclusion (LAVE) method was examined. The magnitude of variation attributable to gender, ages and regions was calculated by the standard deviation ratio (SDR). Sources of variations: age, BMI, physical exercise and smoking levels were investigated by using the multiple regression analysis. SDRs for gender, age and regional differences were significant for 14, 8 and 2 analytes, respectively. BMI-related changes in test results were noted conspicuously for CRP. For some metabolic related parameters the ranges of RIs by non-parametric method were wider than by the parametric method and RIs derived using the LAVE method were significantly different than those without it. RIs were derived with and without gender partition (BMI, drugs and supplements were considered). RIs applicable to Saudis were established for the majority of chemistry analytes, whereas gender, regional and age RI partitioning was required for some analytes. The elevated upper limits of metabolic analytes reflects the existence of high prevalence of metabolic syndrome in Saudi population.

Lipopolysaccharide significantly influences the hepatic triglyceride metabolism in growing pigs.

BackgroundIn the practical commercial pig farms, inflammation is a perennial problem, yet most of studies on inflammation are focused on immune response. Actually, inflammation can induce body metabolism disorder which will finally influence animals’ growth. In this study, we investigated the effect of acute inflammation on the triglyceride (TG) metabolism in the liver of growing pigs and the possible underlying mechanisms.MethodsTwelve male growing pigs were randomly divided into two groups, a control group (received saline) and a LPS group (intramuscular injected with 15 μg/kg LPS). Six hours after LPS injection, the pigs were euthanized and sampled. Biochemical indexes, inflammation factors, lipid metabolism related parameters and mitochondrial function were evaluated. The relationship between glucocorticoid receptor (GR) and the key enzymes of de novo lipogenesis were also investigated by chromatin immunoprecipitation assay (ChIP).ResultsLPS induced a serious inflammation in the liver of growing pigs proved by liver morphologic changes, the up-regulated plasma cortisol, tumor necrosis factor-α (TNF-α) content and gene expression of inflammation related genes in liver. For de novo lipogenesis, LPS significantly decreased the gene expression of fatty acid synthase (FAS), Acetyl-CoA carboxylase-1 (ACC-1) and Stearoyl-CoA desaturase-1 (SCD-1), and the protein expression of ACC-1 and SCD-1. For lipolysis, only the gene expression of adipose triglyceride lipase (ATGL) was decreased. LPS did nothing to the gene expression of hormone-sensitive lipase (HSL) and the lipolytic enzymes activities. For β-oxidation, LPS significantly increased the protein expression of CPT-1α, but the gene expression of mitochondrial DNA-encoded genes and the activities of mitochondrial complex IV and V demonstrated no obviously changes. Furthermore, ChIP results showed that LPS significantly decreased the level of GR binding to ACC-1 promoter.ConclusionLPS infection has a profound impact on hepatic TG metabolism. This impact is mainly demonstrated by the significantly deceased de novo lipogenesis, and GR may involve in its regulation.

Effect of creatine monohydrate supplementation on carcass traits, meat quality and postmortem energy metabolism of finishing pigs

The objective of this study was to evaluate the effects of creatine monohydrate (CMH) supplementation on meat quality and postmortem energy metabolism of finishing pigs. In total, 48 healthy Duroc–Large White cross castrated male pigs were randomly allocated into two treatments, and fed either a CHM-free basal diet or a basal diet with CMH supplementation (0.8%) for 14 days. At the end of the experiment, six pigs from each treatment were weighed individually and slaughtered. The muscle from longissimus dorsi was collected to evaluate the meat quality and energy metabolism-related parameters. The results showed that CMH supplementation did not affect the loin eye area, back fat depth or dressing percentage (P > 0.05). The muscle pH45 min was higher, whereas drip loss and cooking loss were lower in the CMH supplementation group (P < 0.05). CMH supplementation increased the concentrations of creatine (P < 0.05), adenosine triphosphate (P < 0.05), adenosine diphosphate (P < 0.01) and creatine kinase activity (P < 0.05), and decreased the concentration of lactic acid (P < 0.05), and the activities of lactate dehydrogenase (P < 0.05) and pyruvate kinase (P < 0.05) in muscle postmortem. However, no differences were observed between groups for chemical composition, textural characteristics and glycolytic potential of longissimus dorsi muscle (P > 0.05). These findings suggest that dietary supplementation with CMH during the finishing period in pigs could delay early pH decline and decrease the rate of glycolysis in postmortem longissimus dorsi muscle resulting in a decreased drip loss.

Association of arteriosclerosis index and oxidative stress markers in school children.

Recent years have seen increased numbers of children with conditions that contribute strongly to atherosclerotic disease, such as passive smoking, obesity, and dyslipidemia. In the present study, we evaluated the utility of non-invasive urinary markers in preventing lifestyle-related diseases by comparing lipid metabolism-related parameters with oxidative stress markers in school children. Subjects were 85 first-grade students. The variables examined included the smoking in subjects' household; exercise habits; height and weight; blood pressure; and plasma total cholesterol, high-density lipoprotein cholesterol, triglyceride, leptin, blood sugar, urinary cotinine, 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostaglandin F2α (IsoP). Of the subjects, 10.6% were obese (% overweight ≥ 20%), 3.5% had a high-risk arteriosclerosis index (AI; 3 ≤ AI < 5), and 29.4% were passive smokers. No significant differences were seen between boys and girls for any of the measurement parameters. Both urinary 8-OHdG (6.8-24.5 ng/mg creatinine) and IsoP (0.9-7.4 ng/mg creatinine) were detected in all subjects, and a significant positive correlation was seen between the two markers. On multiple regression analysis using AI as an objective variable and all non-invasive markers as explanatory variables, urinary IsoP correlated most strongly with AI (P ≤ 0.01). Risk factors for atherosclerosis in adults, such as obesity and hypercholesterolemia, are associated with oxidative stress and inflammation. The present findings of the strongest correlation between urinary IsoP and AI suggest that urinary IsoP may serve as a non-invasive and effective early marker in predicting risk in children of developing lifestyle-related diseases.

The changes of serum glypican4 in obese patients with different glucose metabolism status.

Glypican 4 (Gpc4) was identified as a novel adipokine capable of intensifying insulin signaling and regulating adipocyte differentiation. This study was performed to investigate the changes of serum Gpc4 levels in obese patients with different glucose metabolism status and its association with metabolic-related parameters. A total of 170 obese patients with different glucose metabolism status and 38 normal controls were recruited, and obese patients were divided into 4 groups: OB1, obese patients with normal glucose tolerance (NGT) and normal insulin levels; OB2, obese patients with normal glucose tolerance and hyperinsulinemia; OB3, obese patients with impaired glucose tolerance; and OB4, obese patients with type 2 diabetes mellitus. Serum Gpc4 was determined by commercially available ELISA kits. Serum Gpc4 levels in the OB2, -3, and -4 groups were significantly increased in comparison with that in the OB1 group (3.5 [2.0-5.3] ng/mL, 3.0 [1.5-6.1] ng/mL, and 3.4 [1.8-5.4] ng/mL vs 1.9 [1.3-4.3] ng/mL, P < .05). The levels were positively correlated with body mass index (BMI), systolic blood pressure (SBP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting insulin (FINS), and homeostasis model assessment of insulin resistance (HOMA-IR) in all subjects. Multiple linear regression showed that SBP, AST, HOMA-IR, and FINS were independent contributors to circulating Gpc4 levels after adjusting for age, gender, and BMI in all subjects (P < .05). Additionally, serum Gpc4 levels in males of the normal group and the OB3 group were higher than those in females (2.9 [2.1-4.9] ng/mL vs 1.6 [1.2-3.1] ng/mL; 4.8 [2.5-6.3] ng/mL vs 2.7 [1.1-4.4] ng/mL, P < .05). Serum Gpc4 levels were significantly elevated in obese patients with insulin resistance and positively correlated with BMI, SBP, ALT, AST, FINS, and HOMA-IR, suggesting Gpc4 is a novel adipokine associated with obesity and insulin resistance-related metabolic disorders.

Serum Myostatin Levels are Elevated in Overweight Patients

Objective: Myostatin has recently been proposed as an important factor that not only regulates skeletal muscle mass, but also body fat mass. The aim of our study is to explore serum myostatin levels in overweight patients and its association with metabolic-related characteristics. Methods: 40 overweight patients and 40 normal weight controls were recruited, and serum myostatin were measured by ELISA methods and the relationships between myostatin and metabolic-related parameters were investigated. Results: Serum myostatin concentrations were significantly increased in overweight patients compared with normal weight controls (10.99±1.99 vs. 9.75±0.96 ng/ml, P=0.001) and positively correlated with body weight (r = 0.272, P=0.015), BMI (r = 0.263, P=0.018), waist circumference (r = 0.291, P=0.009), hip circumference (r = 0.336, P=0.002) and TNF-α (r = 0.611, P&lt;0.001) in all subjects. Contrarily, serum adiponectin levels were negatively associated with body weight (r = -0.270, P=0.018), waist-to-hip ratio (WHR) (r = -0.253, P=0.027), TG (r = -0.235, P=0.040), ALT (r = -0.268, P=0.019), uric acid (UA) (r = -0.262, P=0.021) and positively correlated with HDL (r = 0.454, P&lt;0.001). Conclusion: Serum myostatin levels in overweight patients are notably increased and positively correlated with BMI, body weight, waist and hip circumference, TNF-α, suggesting myostatin is a metabolic regulatory factor.

Association between hepatitis B virus infection and metabolic syndrome: a retrospective cohort study in Shanghai, China.

BackgroundMetabolic syndrome (MS) and hepatitis B (HBV) infection are two major public health problems in China. There are few studies about their association, and the results of these studies are contradictory. We conducted a retrospective cohort study to assess the association between MS and HBV in a Shanghai community-based cohort.MethodsNine hundred seventy-six Shanghai residents were recruited from the Putuo community. 480 HBV infections were in exposed group and 496 non-infections in unexposed group. All metabolic-related parameters and hepatitis B serology were tested with routine biochemical or immunological methods. “Exposed” was defined by HBV infection represented by hepatitis B surface antigen (HBsAg) and without anti-virus treatment. “Unexposed” were subjects who didn’t infect with HBV (Represented by HBsAg) and no MS when they entered the cohort. MS was defined based on the updated National Cholesterol Education Program Adult Treatment Panel III criteria. The Cox proportional hazards model was used to estimate the hazard ratios (HR) and related 95% confidence intervals (95% CI) for the association between HBV infection and MS over a 20-year follow-up period.ResultsOf 976 subjects recruited, 480 had latent HBV infection (exposed subjects). After adjusting for age, the crude HR was 2.46 (95% CI: 1.77, 3.41). After adjusting for potential risk factors of MS (age, gender, smoking, passive smoking, alcohol consumption, physical activity, and diet), the HR was 2.27 (95% CI: 1.52, 3.38).ConclusionsThis 20-year follow-up retrospective cohort study in Shanghai showed a positive association between HBV infection and MS.

Serum Levels of the Adipokine Zinc-α2-glycoprotein Are Decreased in Patients with Hypertension

Objective. Zinc-α2-glycoprotein (ZAG) has recently been proposed as a new adipokine involved in body weight regulation. The purpose of this study is to investigate serum levels of ZAG in patients with hypertension and its association with related characteristics. Methods. 32 hypertension patients and 42 normal controls were recruited and the relationship between serum ZAG, total and high molecular weight (HMW) adiponectin, and tumor necrosis factor-α (TNFα) determined by enzyme-linked immunosorbent assay (ELISA) and metabolic-related parameters was investigated. Results. Serum ZAG concentrations were significantly lowered in patients with hypertension compared with healthy controls (61.4 ± 32 versus 78.3 ± 42 μg/mL, P < 0.05). The further statistical analysis demonstrated that serum ZAG levels were negatively correlated with waist-to-hip ratio (WHR) (r = −0.241, P < 0.05) and alanine aminotransferase (ALT) (r = −0.243, P < 0.05). Additionally, serum HMW adiponectin significantly decreased, while TNFα greatly increased in hypertension patients as compared with healthy controls (2.32 ± 0.41 versus 5.24 ± 1.02 μg/mL, 3.30 ± 1.56 versus 2.34 ± 0.99 pg/mL, P < 0.05). Conclusions. Serum ZAG levels are significantly lowered in hypertension patients and negatively correlated with obesity-related item WHR, suggesting ZAG is a factor associated with hypertension.

Short-term handling stress affects the humoral immune responses of juvenile Atlantic cod, Gadus morhua

Juveniles of Atlantic cod, Gadus morhua L., weighing 30–50 g were subjected to short-term handling stress by exposing them to air for 3 min and immediately placing in the rearing tank for recovery. Indices for the primary stress response as well as selected immune- and metabolism-related parameters were measured in the plasma before the application of the stressor and at 1-h, 24-h and 7-day post-stress. Plasma cortisol significantly increased at 1-h post-stress then returned to the prestress levels at 24-h post-exposure. Plasma glucose and total antioxidant capacity had two peaks at 1 h and 7 days after handling stress. Alkaline phosphatase significantly increased at 24-h post-exposure, while no significant changes in myeloperoxidase activity was observed. Lysozyme and antiprotease activities were significantly downregulated at 1- and 24-h post-exposure, respectively. These findings showed that short-term handling stress in Atlantic cod juveniles resulted in temporal elevation of the primary stress response and metabolism with a corresponding decrease in its defense against bacterial pathogens.

The modulation of catecholamines on immune response of scallop Chlamys farreri under heat stress

Catecholamines (CAs) play key roles in mediating the physiological responses to various stresses. In the present study, the expression of CA-related genes were examined in the hemocytes of scallop Chlamys farreri under heat stress, and several immune or metabolism-related parameters were investigated after heat stress and adrenoceptor antagonist stimulation. After the scallops were cultured at 28°C, the mRNA expression level of dopa decarboxylase (CfDDC) and α-adrenoceptor (CfαAR) increased significantly (P<0.01), whereas that of monoamine oxidase (CfMAO) was down-regulated in the first 6h (P<0.05), and then up-regulated to the maximum level at 24h (P<0.01). In the hemocytes of scallops injected with adrenoceptor antagonist, the expression levels of peptidoglycan-recognition protein (CfPGRP-S1) and C-type lectin (CfLec-1) began to increase significantly at 2 and 3h post propranolol and high temperature treatment, respectively (P<0.01). While the up-regulation of heat shock protein 70 (CfHSP70) post heat stress was significantly inhibited by prazosin injection (P<0.01), and that of hexokinase (CfHK) was inhibited by both prazosin and propranolol injection (P<0.01). Moreover, the remarkable increase of relative specific activity of SOD in the hemolymph post heat stress (P<0.01) was further up-regulated early after prazosin or propranolol injection (P<0.01), while that of the relative anti-bacterial ability was down-regulated by prazosin or propranolol treatment (P<0.01). These results collectively indicated that the catecholaminergic neuroendocrine system in scallop could be activated by heat stress to release CAs, which subsequently modulated the immune response and energy metabolism via α- and β-adrenoceptors.

Intact Parathyroid Hormone is Associated with Cardiac Hypertrophy Independent of Serum Calcium and Inorganic Phosphate

Deranged calcium-phosphate homeostasis is known to be associated with increased cardiac events. We have examined the relationship between calcium-phosphate metabolism-related parameters and cardiac hypertrophy.

Association between Circulating Fibroblast Growth Factor 23, α-Klotho, and the Left Ventricular Ejection Fraction and Left Ventricular Mass in Cardiology Inpatients

BackgroundFibroblast growth factor 23 (FGF23), with its co-receptor Klotho, plays a crucial role in phosphate metabolism. Several recent studies suggested that circulating FGF23 and α-Klotho concentrations might be related to cardiovascular abnormalities in patients with advanced renal failure.PurposeUsing data from 100 cardiology inpatients who were not undergoing chronic hemodialysis, the association of circulating levels of FGF23, α-Klotho, and other calcium-phosphate metabolism-related parameters with the left ventricular ejection fraction (LVEF) and left ventricular mass (LVM) was analyzed.Methods and ResultsLVEF was measured using the modified Simpson method for apical 4-chamber LV images and the LVM index (LVMI) was calculated by dividing the LVM by body surface area. Univariate analysis showed that log transformed FGF23, but not that of α-Klotho, was significantly associated with LVEF and LVMI with a standardized beta of −0.35 (P<0.001) and 0.26 (P<0.05), respectively. After adjusting for age, sex, estimated glomerular filtration rate, and serum concentrations of intact parathyroid hormone, and 25-hydroxyvitamin D as covariates into the statistical model, log-transformed FGF23 was found to be a statistically positive predictor for decreased left ventricular function and left ventricular hypertrophy.ConclusionsIn cardiology department inpatients, circulating FGF23 concentrations were found to be associated with the left ventricular mass and LVEF independent of renal function and other calcium-phosphate metabolism-related parameters. Whether modulation of circulating FGF23 levels would improve cardiac outcome in such a high risk population awaits further investigation.

Nickel-induced changes in carbon metabolism in wheat shoots

In this study, we analyzed the toxic effect of Ni during the development of wheat shoots. Typical developmental alterations in carbon metabolism-related parameters reflecting changes associated with the transition of the seedlings from heterotrophic to autotrophic metabolism were observed in the control shoots between the 1st and the 4th days. Adverse effects of 50 and 100μM Ni became evident starting from the 4th day of growth on the metal-containing media. We found that Ni-induced stimulation of phosphoenolpyruvate carboxylase (PEPC) activity coincided with decrease in the ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) level and with declines in net photosynthetic rate (PN) and stomatal conductance (gs). Application of Ni resulted in increased activities of several dehydrogenases: glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), isocitrate dehydrogenase (NADP-ICDH) and malate dehydrogenase (NADH-MDH). In contrast, the activities of malic enzymes (NADP-ME and NAD-ME) decreased due to Ni stress. Treatment with Ni led to accumulation of glucose and declined concentration of sucrose as well as considerable increases in concentrations of malic and citric acids. Our results indicate that Ni stress redirects the carbon metabolism of developing wheat shoots to provide carbon skeletons for synthesis of amino acids and organic acids as well as to supply reducing power to sustain normal metabolic processes and to support defense mechanisms against oxidative stress.

Serum Liver Fatty Acid Binding Protein Levels Correlate Positively with Obesity and Insulin Resistance in Chinese Young Adults

BackgroundLiver fatty acid–binding protein (FABP1) plays an inconclusive role in adiposity. We investigated the association of serum FABP1 levels with obesity and insulin resistance in Chinese young people under 30 years old.Methodology and Principal FindingsCross-sectional analysis including 200 obese and 172 normal-weight subjects matched for age and sex, anthropometric measurements were performed and serum FABP1 and biochemical characteristics were measured. Insulin resistance was determined by homeostasis model assessment of insulin resistance (HOMA-IR) and by the insulin sensitivity index (Si) derived from Bergman’s minimal model. FABP1 levels in obese subjects were significantly higher than those in normal-weight subjects (p<0.001) and the significance remained after adjustment for age, gender, alanine and aspartate aminotransferases (p<0.001). Serum FABP1 levels were significantly correlated with many metabolic-related parameters, with BMI and triglycerides as the independent determinants. FABP1 levels remained an independent risk factor of insulin resistance assessed by binary Si (OR = 1.868 per SD unit, 95% CI [1.035–3.373], p = 0.038) after adjustment for age, sex, BMI, waist circumference, systolic blood pressure, serum triacylglycerol, total cholesterol, HDL- and LDL-cholesterol,. FABP1 levels were also elevated with an increasing number of components of the metabolic syndrome (p for trend <0.001). Multiple regression modeling for the MetS and its components demonstrated that hypertriglyceridemia and low HDL-cholesterol were significantly correlated to serum FABP1 levels.Conclusions and SignificanceSerum FABP1 correlates positively with obesity and insulin resistance in Chinese young adults. Our data supports the fact that FABP1 might be an important mediator participating in fatty acid metabolism and energy balance.

NAFLD and associated changes in serum Pro-hepcidin, Iron, Ferritin R levels and total iron binding capacity in weaning Rattus norvegicus

Background/aim: Excessive iron deposition in body is hazardous to life. Among many reasons of iron overload, NAFLD is under surveillance now a day. The purpose of the present experimental study was to analyse the impact of fat induced NAFLD and fat reducing agents on iron metabolism. Methodology: Four groups (n=10) of weaning Rattus norvegicus (30g) were designated as Control (Con), I, II, and III. Con group was fed on normal rat chow, I, II and III were provided with diet ''A'' (33% carbohydrate + 33% fat + 34% rat chow). The diets of group II and III were provided with 5% Nigella sativa and 5% Plantago ovata as supplements respectively. After keeping the animals under experimental conditions for 16 weeks, serum samples were taken to analyse iron metabolism related parameters. Results: In comparison with Con group serum concentration of pro-hepcidin was significantly increased in group I (P<0.01) and III (P<0.05) but significantly decreased in II (P<0.05). The inter group comparison revealed that pro-hepcidin concentration was significantly low in group II (P<0.001) as compared to group I and III. There were significantly higher values of Ferritin R in group I as compared to Con (P<0.01), II (P<0.001) and III (0.01). The serum concentration of iron was significantly higher in group I in comparison with Con (P<0.01), II (P<0.01) and III (P<0.05). Total iron binding capacity was lower in group II when compared with group I and III (P<0.05). Conclusion: Conclusively, we can say that pro-hepcidin, iron and ferritin R concentrations as well as total iron binding capacity are associated with NAFLD. N. sativa and P. ovata have impact on iron regulation in diet induced NAFLD.

Thyroid hormone metabolism and environmental chemical exposure

BackgroundPolychlorinated dioxins and –furans (PCDD/Fs) and polychlorinated-biphenyls (PCBs) are environmental toxicants that have been proven to influence thyroid metabolism both in animal studies and in human beings. In recent years polybrominated diphenyl ethers (PBDEs) also have been found to have a negative influence on thyroid hormone metabolism. The lower brominated flame retardants are now banned in the EU, however higher brominated decabromo-diphenyl ether (DBDE) and the brominated flame retardant hexabromocyclododecane (HBCD) are not yet banned. They too can negatively influence thyroid hormone metabolism. An additional brominated flame retardant that is still in use is tetrabromobisphenol-A (TBBPA), which has also been shown to influence thyroid hormone metabolism.Influences of brominated flame retardants, PCDD/F’s and dioxin like-PCBs (dl-PCB’s) on thyroid hormone metabolism in adolescence in the Netherlands will be presented in this study and determined if there are reasons for concern to human health for these toxins. In the period 1987-1991, a cohort of mother-baby pairs was formed in order to detect abnormalities in relation to dioxin levels in the perinatal period. The study demonstrated that PCDD/Fs were found around the time of birth, suggesting a modulation of the setpoint of thyroid hormone metabolism with a higher 3,3’, 5,5’tetrathyroxine (T4) levels and an increased thyroid stimulating hormone (TSH). While the same serum thyroid hormone tests (- TSH and T4) were again normal by 2 years of age and were still normal at 8-12 years, adolescence is a period with extra stress on thyroid hormone metabolism. Therefore we measured serum levels of TSH, T4, 3,3’,5- triiodothyronine (T3), free T4 (FT4), antibodies and thyroxine-binding globulin (TBG) in our adolescent cohort.MethodsVena puncture was performed to obtain samples for the measurement of thyroid hormone metabolism related parameters and the current serum dioxin (PCDD/Fs), PCB and PBDE levels.ResultsThe current levels of T3 were positively correlated to BDE-99. A positive trend with FT4 and BDE-99 was also seen, while a positive correlation with T3 and dl-PCB was also seen. No correlation with TBG was seen for any of the contaminants. Neither the prenatal nor the current PCDD/F levels showed a relationship with the thyroid parameters in this relatively small group.ConclusionOnce again the thyroid hormone metabolism (an increase in T3) seems to have been influenced by current background levels of common environmental contaminants: dl-PCBs and BDE-99. T3 is a product of target organs and abnormalities might indicate effects on hormone transporters and could cause pathology. While the influence on T3 levels may have been compensated, because the adolescents functioned normal at the time of the study period, it is questionable if this compensation is enough for all organs depending on thyroid hormones.

Mechanism of nitrogen metabolism-related parameters and enzyme activities in the pathophysiology of autism

BackgroundThere is evidence that impaired metabolism play an important role in the etiology of many neuropsychiatric disorders. Although this has not been investigated to date, several recent studies proposed that nitrogen metabolism-related parameters may have a pathophysiological role in autism.MethodsThe study enrolled 20 Saudi boys with autism aged 4 to 12 years and 20 healthy controls matched for age and gender. Levels of creatine, urea, ammonia, gamma-aminobutyric acid (GABA), glutamate:glutamine (Glu:Gln) ratio, and enzymatic activities of glutamate dehydrogenase, 5'-nucleotidase, and adenosine deaminase (ADA) were determined in plasma samples from both groups.ResultsWe found a significant elevation of creatine, 5'-nucleotidase, GABA, and glutamic acid and a significant decrease in the enzymatic activity of ADA and glutamine level in patients with autism compared with healthy controls. The most significant variation between the two groups was found in the Glu:Gln ratio.ConclusionA raised Glu:Gln ratio together with positive correlations in creatine, GABA, and 5'-nucleotidase levels could contribute to the pathophysiology of autism, and might be useful diagnostic markers. The mechanism through which these parameters might be related to autism is discussed in detail.

Resistance training changes LDL metabolism in normolipidemic subjects: A study with a nanoemulsion mimetic of LDL

ObjectiveTo evaluate the effects of resistance training (RT) on the metabolism of an LDL-like nanoemulsion and on lipid transfer to HDL, an important step of HDL metabolism. MethodsLDL-like nanoemulsion plasma kinetics was studied in 15 healthy men under regular RT for 1–4 years (age=25±5 years, VO2peak=50±6mL/kg/min) and in 15 healthy sedentary men (28±7 years, VO2peak=35±9mL/kg/min). LDL-like nanoemulsion labeled with 14C-cholesteryl-ester and 3H-free-cholesterol was injected intravenously, plasma samples were collected over 24-h to determine decay curves and fractional clearance rates (FCR). Lipid transfer to HDL was determined in vitro by incubating of plasma samples with nanoemulsions (lipid donors) labeled with radioactive free-cholesterol, cholesteryl-ester, triacylglycerols and phospholipids. HDL size, paraoxonase-1 activity and oxidized LDL levels were also determined. ResultsThe two groups showed similar LDL and HDL-cholesterol and triacylglycerols, but oxidized LDL was lower in RT (30±9 vs. 61±19U/L, p=0.0005). In RT, the nanoemulsion 14C-cholesteryl-ester was removed twice as fast than in sedentary individuals (FCR: 0.068±0.023 vs. 0.037±0.028, p=0.002), as well as 3H-free-cholesterol (0.041±0.025 vs. 0.022±0.023, p=0.04). While both nanoemulsion labels were removed at the same rate in sedentary individuals, RT 3H-free-cholesterol was removed slower than 14C-cholesteryl-ester (p=0.005). HDL size, paraoxonase 1 and the transfer rates to HDL of the four lipids were the same in both groups. ConclusionsRT accelerated the clearance of LDL-like nanoemulsion, which probably accounts for the oxidized LDL levels reduction in RT. RT also changed the balance of free and esterified cholesterol FCR's. However, RT had no effect on HDL metabolism related parameters.

Association between metabolic abnormalities and HBV related hepatocelluar carcinoma in Chinese: A cross-sectional study

BackgroundPrevious studies suggested that the abnormality of metabolism is a newly identified risk factor in HBV-related hepatocellular carcinoma (HCC). The association between metabolic factors and hepatocellular carcinoma (HCC) has not been clarified up to now. This study was conducted to investigate the prevalence of metabolic abnormalities in HCC and to probe the association between metabolic parameters and liver function as well, so as to evaluate the interactions between metabolism and the development of HBV-related HCC.MethodsTotally 179 cases of HBV-related HCC, who were surgically treated and pathologically confirmed were enrolled. HBV carriers (n = 100) and healthy controls (n = 150) were recruited from routine physical examination during the same period. Body mass index (BMI) was obtained from medical documentation. All the metabolic-related parameters and liver function tests were determined with routine biochemical or immunological analytic methods. Malondialdehyde (MDA) and total antioxidant capacity(TAOC)were detected by chemical analytic methods. A stratified analysis was conducted according to BMI, glycated albumin (GA), free fatty acids (FFA), and the relationships between the metabolic-related parameters and liver functions were analyzed in HCC and control subjects.ResultsHCC group showed significantly high levels of mean BMI, serum glucose, low serum lipids levels than controls (P < 0.05). Acquired by stratified analysis, the higher the BMI, the higher level of insulin and homeostasis model assessment for insulin resistance (HOMA-IR) (P < 0.01) were found in HCC patients. Elevated level of MDA and γ-glutamyltransferase (GGT) were revealed in those with high serum FFA level for the first time. Strong associations between metabolic factors and liver function were shown in HCC (P < 0.05). Higher GA level was strongly associated with increased risk of cancer compared to healthy controls (OR = 9.87, 95% confidence interval: 1.86~52.29). Serum triglycerides (TG) and low-density lipoprotein cholesterol (LDL-C) levels were negative contributory factors for HCC (OR = 0.05, 95% confidence interval: 0.01~0.27 and OR = 0.32, 95% confidence interval, 0.11~0.95: respectively).ConclusionsMetabolic abnormalities are closely associated with the occurrence and development of HBV-related HCC. Oxidative stress and/or lipid peroxidation might be involved in the pathogenesis and acceleration of liver function impairments in HCC.