How do Different Indices of Obesity Correlate with Cardiometabolic Disease Risk Factors in Multiethnic Youths?

ObjectiveTo investigate the relationship between cardiometabolic disease risk factors (CDRFs) among ethnic minorities and anthropometric factors including body mass index z score, waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHTR) in Hispanic and non-Hispanic black youths originating primarily from Central America, South America, and the Caribbean.MethodsClinical data of 167 young persons 2 to 19 years of age encountered in an outpatient pediatric endocrinology clinic were analyzed. The CDRFs included fasting insulin and glucose, homeostasis model assessment of insulin resistance (HOMA-IR), systolic blood pressure (SBP) and diastolic blood pressure (DBP), high-density lipoprotein cholesterol, triglycerides, cardiac C-reactive protein (CRP), and apolipoproteins.ResultsFor both the non-Hispanic black and the Hispanic youths, WC was significantly correlated with SBP (r = 0.63; P < .001 and r = 0.50; P < .001, respectively), DBP (r = 0.61; P < .001 and r = 0.47; P < .001, respectively), and cardiac CRP (r = 0.76; P < .001 and r = 0.26; P = .026, respectively). Similarly, WHTR was significantly correlated with SBP, DBP, and cardiac CRP for the non-Hispanic black study subjects, whereas SBP (r = 0.22; P = .01), DBP ( r = 0.34; P < .001), fasting insulin ( r = 0.43; P < .001), HOMA-IR (r = 0.38; P < .001), apolipoprotein A-I (r = 0.30; P = .01), and CRP (r = 0.44; P < .001) were significantly correlated for the Hispanic group. For both groups, body mass index z score was not consistently correlated with CDRFs, and waist-to-hip ratio was not significantly correlated with any CDRFs, except for apolipoprotein B in non-Hispanic black youths.ConclusionOur study shows that WC and WHTR may be useful anthropometric factors for better identification of ethnic minority youths at risk for adult-onset cardiometabolic disease. (Endocr Pract. 2009;15:403-409)     

Effects of dietary conjugated linoleic acid on metabolic status,BW and expression of genes related to lipid metabolism in adipose tissue of dairy cows during peripartum

Conjugated linoleic acid (CLA) dietary supplementation reduces milk fat content and yield, but its effects on lipid metabolism and energy status remain controversial. The objective of this study was to investigate the effects of dietary CLA on adipose tissue (AT) mRNA abundance of genes related to lipid metabolism, plasma indicators of metabolic status, body condition score (BCS) and BW changes in dairy cows. Sixteen multiparous Holstein cows (3.2 ± 1.4 lactations, 615 ± 15 kg BW) were randomly assigned to treatments: 1) CLA; rumen-protected CLA (75 g/d) or 2) Control; equivalent amount of rumen inert fatty acid (FA) as the previous diet (78 g/d), from − 20.2 ± 3.2 (mean ± SEM) to 21 d relative to calving (d 0). Subcutaneous AT was biopsied from the tail-head region at d 21 to determine the mRNA abundance of genes related to lipid metabolism. Blood samples were collected at − 20.2 ± 3.2, 0, 7, 14 and 21 d relative to calving to determine plasma non-esterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), insulin and glucose. Conjugated linoleic acid decreased milk fat yield and milk fat content by 15 and 16%, respectively. Cows fed CLA had lower plasma NEFA and BHBA and greater glucose and insulin concentrations (P < 0.05). Mean BCS at 21 d postpartum was greater (P < 0.01; 2.89 vs 2.25), and BCS loss from the day of enrollment to 21 d postpartum was reduced (P < 0.01; − 0.13 vs − 0.64) in the CLA group. The expression of acylcoenzyme A oxidase, carnitine palmitoyltransferase 1A, hormone-sensitive lipase, β2 adrenergic receptor and acetyl-CoA carboxylase was downregulated by CLA supplementation, whereas the expression of sterol regulatory element binding protein, lipoprotein lipase and peroxisome proliferator-activated receptor gamma was upregulated (P < 0.01). In summary, CLA-supplemented cows showed signs of better metabolic status and less severe fat mobilization. Moreover, CLA increased mRNA abundance of genes related to lipogenesis and decreased mRNA abundance of genes related to FA oxidation and lipolysis in the AT of dairy cows during early lactation.     

The roles of aerobic exercise training and suppression IL-6 gene expression by RNA interference in the development of insulin resistance

ObjectiveTo demonstrate the hypothesis that aerobic exercise training inhibits the development of insulin resistance through IL-6 and probe into the possible molecular mechanism about it.MethodsRats were raised with high-fat diets for 8 weeks to develop insulin resistance, and glucose infusion rates (GIRs) were determined by hyperinsulinemic–euglycemic clamping to confirm the development of insulin resistance. Aerobic exercise training (the speed and duration time in the first week were respectively 16 m/min and 50 min, and speed increased 1 m/min and duration time increased 5 min every week following it) and/or IL-6shRNA plasmid injection (rats received IL-6shRNA injection via the tail vein every two weeks) were adopted during the development of insulin resistance. The serum IL-6, leptin, adiponectin, fasting blood glucose, fasting serum insulin, GIR, IL-6 gene expression levels, p-p38 in various tissues and p-STAT3/t-STAT3 ratio in the liver were measured.ResultsRats fed with high-fat diets for 8 weeks were developed insulin resistance and the IL-6mRNA levels of IL-6shRNA injection groups in various tissues were significantly lower than those of control group (P < 0.05), respectively. The development of insulin resistance in exercise rats significantly decreased, however, compared with that, the GIR of exercise rats injected by IL-6shRNA was lower (P < 0.05). The IL-6mRNA levels were highest in the fat tissue and lowest in the skeletal muscles in all the rats. The serum adiponectin levels decreased (P < 0.05) following the development of insulin resistance, and it increased (P < 0.05) when the rats were intervened by aerobic exercise training for 8 weeks at the same time. However, there were not significant differences when serum leptin concentrations were compared (P > 0.05). The p-p38 significantly increased in the rats fed with high-fat diets, however, p-p38 of the exercise high-fat diets rats in the liver and fat tissues significantly decreased than that (P < 0.05). The changes of p-p38 in exercise rats injected by IL-6shRNA were irregular. The activation of STAT3 in the liver significantly increased (P < 0.05) following the development of insulin resistance, and it decreased (P < 0.05) when the rats were intervened by aerobic exercise training for 8 weeks at the same time, and the gene silencing of IL-6 did not have effects on the activation of STAT3 in the liver (P > 0.05).ConclusionsIn conclusion, aerobic exercise training prevented the development of insulin resistance through IL-6 to a certain degree. The gene expression and secretion of IL-6 could inhibit the development of insulin resistance. The mechanism of the effects were possibly related with elevating the levels of serum adiponectin, and/or inhibiting the activation of STAT3 in the liver and p38MAPK in the skeletal muscles, liver and fat tissues.     

Plasma levels of trace elements and exercise induced stress hormones in well-trained athletes

This study analyzed the variation and relationship of several trace elements, metabolic substrates and stress hormones activated by exercise during incremental exercise. Seventeen well-trained endurance athletes performed a cycle ergometer test: after a warm-up of 10 min at 2.0 W kg⁻¹, the workload was increased by 0.5 W kg⁻¹ every 10 min until exhaustion. Prior diet, activity patterns, and levels of exercise training were controlled, and tests timed to minimize variations due to the circadian rhythm. Oxygen uptake, blood lactate concentration, plasma ions (Zn, Se, Mn and Co), serum glucose, non-esterified fatty acids (NEFAs) and several hormones were measured at rest, at the end of each stage and 3, 5 and 7 min post-exercise. Urine specific gravity was measured before and after the test, and participants drank water ad libitum.Significant differences were found in plasma Zn and Se levels as a function of exercise intensity. Zn was significantly correlated with epinephrine, norepinephrine and cortisol (r = 0.884, P < 0.01; r = 0.871, P < 0.01; and r = 0.808, P = 0.05); and Se showed significant positive correlations whit epinephrine and cortisol (r = 0.743, P < 0.05; and r = 0.776, P < 0.05). Neither Zn nor Se levels were associated with insulin or glucagon, and neither Mn nor Co levels were associated with any of the hormones or substrate metabolites studied. Further, while Zn levels were found to be associated only with lactate, plasma Se was significantly correlated with lactate and glucose (respectively for Zn: r = 0.891, P < 0.01; and for Se: r = 0.743, P < 0.05; r = 0.831, P < 0.05).In conclusion, our data suggest that there is a positive correlation between the increases in plasma Zn or Se and stress hormones variations induced by exercise along different submaximal intensities in well-hydrated well-trained endurance athletes.     

The relationship between interleukin-6 in saliva,venous and capillary plasma,at rest and in response to exercise

IL-6 plays a mechanistic role in conditions such as metabolic syndrome, chronic fatigue syndrome and clinical depression and also plays a major role in inflammatory and immune responses to exercise. The purpose of this study was to investigate the levels of resting and post exercise IL-6 when measured in venous plasma, saliva and capillary plasma. Five male and five females completed 2 separate exercise trials, both of which involved standardized exercise sessions on a cycle ergometer. Venous blood and saliva samples were taken immediately before and after Trial A, venous and capillary blood samples were taken immediately before and after Trial B. IL-6 values were obtained using a high-sensitivity enzyme-linked immunosorbent assay (ELISA). In Trial A venous plasma IL-6 increased significantly from 0.4 ± 0.14 pg/ml to 0.99 ± 0.29 pg/ml (P < 0.01) while there was no increase in salivary IL-6. Venous plasma and salivary IL-6 responses were not correlated at rest, post exercise or when expressed as an exercise induced change. In Trial B venous and capillary plasma IL-6 increased significantly (venous: 0.22 ± 0.18 to 0.74 ± 0.28 pg/ml (P ⩽ 0.01); capillary: 0.37 ± 0.22 to 1.08 ± 0.30 pg/ml (P < 0.01). Venous and capillary plasma responses did not correlate at rest (r = 0.59, P = 0.07) but did correlate post exercise (r = 0.79, P ⩾ 0.001) and when expressed as an exercise induced change (r = 0.71, P = 0.02). Saliva does not appear to reflect systemic IL-6 responses, either at rest or in response to exercise. Conversely, capillary plasma responses are reflective of systemic IL-6 responses to exercise.     

Association between selenium nutritional status and metabolic risk factors in men with visceral obesity

Background and aimPrevious evidence has suggested an association between selenium and cardiovascular disease, which is main outcome of metabolic syndrome. The aim of this study was to examine possible correlation between selenium nutritional status and metabolic risk factors in men with visceral obesity.MethodsPlasma samples were collected from 123 Indonesian men with visceral obesity. Their metabolic risk factors and selenium nutritional status were analyzed. The eligible subjects (n = 78) were stratified according to the International Diabetes Federation: obese, obese plus one component, and obese plus two components or more. Obese plus two components or more were diagnostic criteria of metabolic syndrome. Pearson's correlation was performed to examine the correlation in each group.ResultsIn the obese group, selenium positively correlated with high-density lipoprotein (HDL) cholesterol (r = 0.390, P < 0.05) and with fatty acid binding protein-4 (FABP4) (r = 0.474, P < 0.05); glutathione peroxidase-3 (GPx3) activity was inversely correlated with FABP4 (r = ?467, P < 0.05). In the obese plus one component group, GPx3 activity positively correlated with HDL cholesterol (r = 0.413, P < 0.05). In the metabolic syndrome group, selenium negatively correlated with monocytes chemoattractant protein (MCP)-1 (r = ?0.429, P < 0.05).ConclusionsThese results show that the association between selenium nutritional status and metabolic risk factors is limited to particular group of obese men with or without metabolic syndrome.     

Effects of Successful Parathyroidectomy on Metabolic Cardiovascular Risk Factors In Patients With Severe Primary Hyperparathyroidism

ObjectiveTo evaluate the effect of parathyroidectomy on metabolic abnormalities associated with cardiovascular disease in patients with primary hyperparathyroidism (PHPT).MethodsThirty-four patients with PHPT (aged 51.0 ± 11.8 years, mean ± standard deviation) underwent assessment before and 1 year after successful parathyroidectomy. A control group of 42 normocalcemic healthy subjects, matched for age and body mass index, was also examined at baseline. We measured serum lipids, glucose, insulin, uric acid, calcium, parathyroid hormone, C-reactive protein, and bone density. Insulin resistance index was evaluated by homeostasis model assessment, and the presence of metabolic syndrome was determined. Because of multiple tests, the level of statistical significance was set at .01.ResultsAfter parathyroidectomy, there was a decrease in diastolic blood pressure (P < .02) and in serum concentrations of uric acid (P < .04) and insulin (P < .009). No difference was observed in rates of metabolic syndrome in patients before and 1 year after parathyroidectomy (23.5% versus 17.6%; P > .46). Insulin resistance index values were also unchanged from before to after parathyroidectomy (1.3 ± 0.9 and 1.1 ± 0.9, respectively; P > .68). A substantial increase in spine bone density (5%; P < .05) was notedpostoperatively. Multivariate logistic regression analysis, after adjustment for age and body mass index, revealed that parathyroidectomy did not lead to a significant decrease in likelihood of cardiovascular risk—odds ratio (OR), 1.82; 95% confidence interval (CI), 0.53 to 6.21 (P > .34) for the metabolic syndrome and OR, 0.82; 95% CI, 0.17 to 3.88 (P > .8) for the insulin resistance index.ConclusionIn this study, surgical treatment had no beneficial effect on cardiovascular risk, as assessed by the metabolic syndrome and insulin resistance markers in patients with PHPT 1 year after parathyroidectomy.(Endocr Pract. 2011;17:584-590)     

Chromium Effects on Glucose Tolerance and Insulin Sensitivity in Persons at Risk for Diabetes Mellitus

ObjectiveTo investigate the effects of daily chromium picolinate supplementation on serum measures of glucose tolerance and insulin sensitivity in patients at high risk for type 2 diabetes mellitus.MethodsWe conducted a randomized, double-blind, placebo-controlled, modified cross-over clinical trial with 6-month sequences of intervention and placebo followed by a 6-month postintervention assessment. Adult patients with impaired fasting glucose, impaired glucose tolerance, or metabolic syndrome were enrolled. Participants received 6-month sequences of chromium picolinate or placebo at 1 of 2 dosages (500 or 1000 mcg daily). Primary outcome measures were change in fasting plasma glucose, 2-hour plasma glucose during oral glucose tolerance testing, fasting and 2-hour insulin, and homeostasis model assessment of insulin resistance (HOMA-IR). Secondary outcomes included anthropometric measures, blood pressure, endothelial function, hemoglobin A_1c, lipids, and urinary microalbumin.ResultsFifty-nine participants were enrolled. No changes were seen in glucose level, insulin level, or HOMA-IR (all P > .05) after 6 months of chromium at either dosage level (500 mcg or 1000 mcg daily) when compared with placebo. None of the secondary outcomes improved with either chromium dosage compared with placebo (P > .05).ConclusionsChromium supplementation does not appear to ameliorate insulin resistance or impaired glucose metabolism in patients at risk for type 2 diabetes and thus is unlikely to attenuate diabetes risk. (Endocr Pract. 2011;17:16-25)     

Serum chemerin levels during normal human pregnancy

During gestation there are important changes in maternal metabolism and an increase in insulin resistance, coinciding with an increase in adiposity. Chemerin is an adipocytokine which is expressed and secreted in various tissues, including placenta, and may play an important role in metabolic regulation during pregnancy. The aim of this study was to determine serum levels of chemerin during gestation and compare them to other indicators of insulin resistance. A cross-sectional study was carried out analyzing serum chemerin levels of 20 pregnant women during three gestational periods, early, middle, and late (between the 10th and 14th, the 23rd and 26th, and the 34th and 37th week) and 20 non-pregnant women were used as a control group. An analysis of chemerin levels during the menstrual cycle was performed in an eumenorrheic group (n = 16) in the early follicular (cycle day 4 ± 1) and the midluteal phase (cycle day 22 ± 1), demonstrating that serum chemerin levels did not fluctuate significantly. Serum levels of chemerin were significantly elevated during late gestation when compared to early (P < 0.001) and middle (P = 0.001) gestation and a negative correlation between serum chemerin and adiponectin levels (r = −0.1643) became more significant when the non-pregnant group was included in the calculations (r = −0.2471). There was no significant association of triglycerides, total cholesterol, LDL, HDL, insulin, and HOMA levels with chemerin. Although chemerin rose significantly and is negatively associated with adiponectin levels, it is not correlated with other markers of insulin sensitivity, suggesting that more study is needed to determine whether chemerin is useful in predicting insulin resistance during gestation.     

Markedly Delayed Insulin Secretion and a High Rate of Undetected Overt Diabetes Characterize Glucose Metabolism in Adult Patients with Cystic Fibrosis After Lung Transplantation

Objective: Cystic fibrosis–related diabetes (CFRD) is associated with adverse clinical outcomes and should be screened for by an annual oral glucose tolerance test (OGTT). Since pathophysiologic studies have mainly been performed in a pediatric/adolescent, nontransplanted collective, we aimed to assess parameters of insulin secretion and sensitivity in adult cystic fibrosis (CF) patients after lung transplantation (LT).Methods: Twelve adult CF patients after LT without known diabetes (33.3 ± 11.5 years; body mass index &lsqb;BMI] 21.5 ± 3.3 kg/m²) and 8 control subjects matched by age (36.0 ± 6.6 years; P>.05), BMI (22.3 ± 1.5 kg/m²; P>.05), and gender (CON group) underwent a 3-hour OGTT with glucose, insulin, and C-peptide measurements. Parameters of insulin secretion and sensitivity as well as lipid profiles were assessed.Results: In the CF group, 4 patients were diagnosed with overt diabetes (CFRD) compared to CF patients without diabetes (CF-noDM), of whom 6 had indeterminate glycemia with 1-h glucose values >200 mg/dL. The insulin peak after glucose load occurred after 30 minutes in CON, after 90 minutes in CF-noDM, and was missing in CFRD. Insulin sensitivity was comparable between the groups. Beta-cell glucose sensitivity was markedly reduced in CFRD (10.7 ± 5.8 pmol/min*m²*mM), higher in CF-noDM (39.9 ± 23.4 pmol/min*m²*mM), but still significantly lower compared to CON (108.3 ± 53.9 pmol/min*m²*mM; P = .0008). CFRD patients exhibited increased triglyceride levels and decreased high-density lipoprotein levels.Conclusion: Adult CF patients after LT have profound disturbances in glucose metabolism, with a high rate of undetected diabetes and markedly delayed insulin secretion. Curbed beta-cell glucose sensitivity rather than insulin resistance explains postprandial hyperglycemia and is accompanied by abnormalities in lipid metabolism.Abbreviations: AUC = area under the curve; BMI = body mass index; CF = cystic fibrosis; CFRD = cystic fibrosis–related diabetes; CFTR = cystic fibrosis transmembrane-conductance regulator; CF-TX = cystic fibrosis patients who underwent lung transplantation; CGM = continuous glucose monitoring; HbA1c = glycated hemoglobin; HDL = high-density lipoprotein; INDET = indeterminate glycemia; LDL = low-density lipoprotein; LT = lung transplantation; OGIS = oral glucose sensitivity index; OGTT = oral glucose tolerance test; QUICKI = quantitative insulin sensitivity check index     

Serum zinc is associated with plasma leptin and Cu–Zn SOD in elite male basketball athletes

This paper investigates the relationship between plasma trace element and plasma leptin, as well as percent fat mass, in 16 male basketball athletes. Blood samples were obtained before intensive training and 24 h after intensive training to measure plasma zinc (Zn), copper (Cu), calcium (Ca), magnesium (Mg), iron (Fe), and leptin levels. High-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), triglyceride (TG), total and cholesterol (TC) levels were determined using commercially available kits for humans. Subjects presented similar values in terms of age (21.1 ± 2.2 years old), body mass index (23.9 ± 2.00 kg/m²), percent body fat (14.40 ± 1.52%), plasma hemoglobin (150.1 ± 9.4 g/L), plasma Zn (17.47 ± 1.28 μmol/l), plasma Cu (13.42 ± 1.40 μmol/L), plasma Ca (2.41 ± 0.14 mmol/L), and plasma Mg (0.96 ± 0.02 mmol/L). The correlation analysis between degree of plasma leptin and plasma element contents was performed using the SPSS 16.0 software. Plasma Zn correlated positively with plasma leptin (r = 0.746, P < 0.01), Cu–Zn SOD (r = 0.827, P < 0.01), and negatively with percent fat mass (r = –0.598, P < 0.05) under no-training conditions. Meanwhile, plasma Cu, Ca, Mg, and Fe did not correlate with plasma leptin or percent fat mass (P > 0.05). In conclusion, plasma Zn may be involved in the regulation of plasma leptin and may serve as a lipid-mobilizing factor in Chinese men's basketball athletes.     

Serum vaspin levels in women with and without gestational diabetes mellitus during pregnancy and postpartum

Although vaspin is regarded an insulin-sensitizing adipokine, its role in gestational diabetes mellitus (GDM) is currently unknown. We aimed to evaluate serum vaspin levels and their correlation with insulin resistance in women with and without GDM. Forty-four women with GDM [GDM Group ? 20 managed with diet only (GDM-diet) and 24 with diet plus insulin (GDM-insulin)] and 44 age-matched pregnant women with normal glucose tolerance (Control Group) were studied. Serum glucose, lipids, uric acid, insulin and vaspin were measured at the 2nd and 3rd trimester of pregnancy and postpartum. The quantitative insulin sensitivity check index (QUICKI) and homeostasis model of assessment–insulin resistance (HOMA-IR) were calculated. Circulating vaspin levels decreased significantly postpartum in all groups (p < 0.001), but did not differ between GDM or GDM Subgroups and Control Group in any time point. At the 3rd trimester of pregnancy vaspin was positively correlated to insulin (p = 0.022), HOMA-IR (p = 0.016) and triglycerides (p = 0.033) and negatively correlated to QUICKI (p = 0.016) in the GDM women, but not in the Controls. These correlations were not observed at the 2nd trimester or postpartum. Vaspin, in contrast to HOMA-IR, could not independently predict GDM in binary logistic regression. In patients with GDM, insulin treatment did not affect vaspin levels. In conclusion, our data suggest that vaspin levels gradually decrease from the 2nd trimester to postpartum; however, decreases are similar between women with or without GDM. Serum vaspin cannot independently predict GDM and it is not affected by the degree of glucose metabolism deregulation or the exogenous administration of insulin.     

Efecto metabólico del ejercicio físico regular en la población sana

AimTo assess the effect of moderate regular aerobic physical activity not associated to body weight changes on insulin resistance and the associated metabolic changes in general population.Sujects and methodsA cross-sectional, observational study in an adult population (n=101 sujects aged 30-70 years) with no personal history of disease and with stable weight in the three months prior to the study. The group with regular exercise performed 30-60 minutes of moderate regular physical exercise 5 days per week (7.5-15 hours MET per week), while a control group performed no regular physical excersice and had a sedentary lifestyle. Subjects were age- and sex-matched. Lipids, lipoproteins, and HOMA index were measured using standard methods.ResultsThe group with regular physical activity consisted of 48 subjects (21 male/27 female), while the group with no regular physical activity included 53 subjects (31 male/22 female). No significant differences were found between the groups in age, sex, BMI, waist circunference, and blood presure. Significant differences were found between the groups in fasting serum triglyceride, HDL-C, and apoB levels. Fasting plasma insulin levels (12.1 ± 4.13 vs 14.9 ± 4.8 mU/L, P= .004) and HOMA index (2.8 ± 1.1 vs 3.5±4.1, P= .001) were significantly lower in the group with regular physical activity as compared to the sedentary group. Prevalence rates of metabolic syndrome were 20.7% and 45.8% (P=.01) in the regular physical activity and sedentary groups respectively.ConclusionModerate regular physical activity is associated to higher insulin sensitivity, an improved lipid profile, and a decrease in components of metabolic syndrome with no change in weight or BMI.     

FOXO 1a and FOXO 3a gene polymorphisms in association with metabolic syndrome

The prevalence and magnitude of childhood and adult obesity and diabetes are increasing dramatically. FOXO 1a and FOXO 3a will be evaluated in this study, in an effort to identify genetic polymorphisms in potential candidate genes that may be associated with body mass index (BMI), and metabolic syndrome (MS). Also to assess whether there is a relation between insulin sensitivity, and genotype, we will test the relation between fasting insulin, glucose, insulin resistance, insulin secretion and genotype.A total number of 248 presenting normal, overweight and obese individuals were recruited; 100 children and 148 adults of both sexes. They were divided by body mass index as follows, normal, overweight and obese. Lipid profile, fasting glucose and insulin HOMA-IR and HOMA-β index and RT-PCR for FOXO 1a and FOXO 3a were performed.An association was found among the studied group (children and adults) as regards foxo3a gene polymorphism and HOMA IR, HOMA B index and T-cholesterol (P = 0.022, 0.011 and 0.028, respectively), while there was only an association between LDL-C and foxo1a gene polymorphism among the studied group of children and adults (P = 0.023).In this study we demonstrated that FOXO3a mutant is correlated with HOMA-IR (marker of insulin resistance), HOMA-B index (marker of insulin secretion) and total cholesterol while as regards FOXO1a there was only an association between LDL cholesterol and mutant type of FOXO1a.     

Plasma trace elements levels are not altered by submaximal exercise intensities in well-trained endurance euhydrated athletes

The purpose of this study was to assess the effect of relative exercise intensity on various plasma trace elements in euhydrated endurance athletes.Twenty-seven well-trained endurance athletes performed a cycloergometer test: after a warm-up of 10 min at 2.0 W kg⁻¹, workload increased by 0.5 W kg⁻¹ every 10 min until exhaustion. Oxygen uptake, blood lactate concentration ([La⁻]_b), and plasma ions (Zn, Se, Mn and Co) were measured at rest, at the end of each stage, and 3, 5 and 7 min post-exercise. Urine specific gravity (U_SG) was measured before and after the test, and subjects drank water ad libitum. Fat oxidation (FAT_OXR), carbohydrate oxidation (CHO_OXR), energy expenditure from fat (EE_FAT), from carbohydrates (EE_CHO) and total EE (EE_T) were estimated using stoichiometric equations. A repeated measure (ANOVA) was used to compare plasma ion levels at each exercise intensity level. The significance level was set at P < 0.05.No significant differences were found in U_SG between, before, and after the test (1.014 ± 0.004 vs. 1.014 ± 0.004 g cm⁻³) or in any plasma ion level as a function of intensity. There were weak significant correlations of Zn (r = 0.332, P < 0.001) and Se (r = 0.242, P < 0.01) with [La⁻]_b, but no relationships were established between [La⁻]_b, VO₂, FAT_OXR, CHO_OXR, EE_FAT, EE_CHO, or EE_T and plasma ion levels.Acute exercise at different submaximal intensities in euhydrated well-trained endurance athletes does not provoke a change in plasma trace element levels, suggesting that plasma volume plays an important role in the homeostasis of these elements during exercise.     

Dpp4 Inhibitor Sitagliptin As A Potential Treatment Option In Metformin-Intolerant Obese Women With Polycystic Ovary Syndrome: A Pilot Randomized Study

Objective: Metformin has an established role in the management of polycystic ovary syndrome (PCOS). Some patients cannot tolerate it due to associated gastrointestinal adverse events. The present study evaluated the dipeptidyl peptidase 4 inhibitor sitagliptin as a potential treatment option in metformin-intolerant PCOS.Methods: We conducted a 12-week, prospective, randomized, open-label study with 30 obese metformin-intolerant women with PCOS (age 35.0 ± 7.2 years; body mass index, 36.9 ± 5.5 kg/m²). After metformin withdrawal, they were randomized to lifestyle intervention and sitagliptin 100 mg daily (SITA) or lifestyle intervention alone as controls (CON). All participants underwent anthropometric and endocrine measurements and oral glucose tolerance testing. Model-derived indexes of insulin resistance and beta-cell function were calculated.Results: SITA improved beta-cell function as assessed by the homeostasis model assessment for beta-cell function index (HOMA-B) of 45.9 ± 35.8 (P = .001), modified beta-cell function index (MBCI) of 7.9 ± 7 (P = .002), and quantitative insulin-sensitivity check index (QUICKI) of -0.03 ± 0.03 (P = .002). By contrast, beta-cell function decreased in CON. The between-group differences were significant for HOMA-B (P = 0.001), MBCI (P = .010), and QUICKI (P = .025). The conversion rate to impaired glucose homeostasis was prevented in SITA: 3 of 15 subjects had impaired glucose tolerance (IGT) before and after the study. In CON, none had type 2 diabetes (T2D), and 4 had IGT at the beginning. After 12 weeks, IGT was observed in 2 and T2D in 3 subjects.Conclusion: SITA improved beta-cell function and prevented a conversion to IGT and T2D in metformin-intolerant obese PCOS patients.Abbreviations: BMI = body mass index; DPP-4 = dipeptidyl peptidase-4; DXA = dual energy X-ray absorptiometry; GIP = glucose-dependent insulinotropic peptide; GLP-1 = glucagon-like peptide-1; HOMA-B = homeostasis model assessment for beta-cell function; HOMA-IR = homeostasis model assessment of insulin resistance; IAI = insulin action index; IGT = impaired glucose tolerance; IR = insulin resistance; MBCI = modified beta-cell function index; OGTT = oral glucose tolerance test; QUICKI = quantitative insulin sensitivity check index; PCOS = polycystic ovary syndrome; SHBG = sex hormone–binding globulin; T2D = type 2 diabetes     

Zinc transporter gene expression and glycemic control in post-menopausal women with Type 2 diabetes mellitus

Type 2 diabetes mellitus (DM) is associated often with underlying zinc deficiency and nutritional supplements such as zinc may be of therapeutic benefit in the disease. In a randomized, double-blind, placebo-controlled, 12-week trial in postmenopausal women (n = 48) with Type 2 DM we investigated the effects of supplementation with zinc (40 mg/d) and flaxseed oil (FSO; 2 g/d) on the gene expression of zinc transporters (ZnT1, ZnT5, ZnT6, ZnT7, ZnT8, Zip1, Zip3, Zip7, and Zip10) and metallothionein (MT-1A, and MT-2A), and markers of glycemic control (glucose, insulin, glycosylated hemoglobin [HbA1c]). The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. No significant effects of zinc or FSO supplementation were observed on glycemic marker concentrations, HOMA-IR or fold change over 12 weeks in zinc transporter and metallothionein gene expression. In multivariate analysis, the change over 12 weeks in serum glucose concentrations (P = 0.001) and HOMA-IR (P = 0.001) predicted the fold change in Zip10. In secondary analysis, marginal statistical significance was observed with the change in both serum glucose concentrations (P = 0.003) and HOMA-IR (P = 0.007) being predictive of the fold change in ZnT6. ZnT8 mRNA expression was variable; HbA1c levels were higher (P = 0.006) in participants who exhibited ZnT8 expression compared to those who did not. The significant predictive relationships between Zip10, ZnT6, serum glucose and HOMA-IR are preliminary, as is the relationship between HbA1c and ZnT8; nevertheless the observations support an association between Type 2 DM and zinc homeostasis that requires further exploration.     

Enhancement in liver SREBP-1c/PPAR-α ratio and steatosis in obese patients: Correlations with insulin resistance and n-3 long-chain polyunsaturated fatty acid depletion

Sterol receptor element-binding protein-1c (SREBP-1c) and peroxisome proliferator-activated receptor-α (PPAR-α) mRNA expression was assessed in liver as signaling mechanisms associated with steatosis in obese patients. Liver SREBP-1c and PPAR-α mRNA (RT-PCR), fatty acid synthase (FAS) and carnitine palmitoyltransferase-1a (CPT-1a) mRNA (real-time RT-PCR), and n-3 long-chain polyunsaturated fatty acid (LCPUFA)(GLC) contents, plasma adiponectin levels (RIA), and insulin resistance (IR) evolution (HOMA) were evaluated in 11 obese patients who underwent subtotal gastrectomy with gastro-jejunal anastomosis in Roux-en-Y and 8 non-obese subjects who underwent laparoscopic cholecystectomy (controls). Liver SREBP-1c and FAS mRNA levels were 33% and 70% higher than control values (P < 0.05), respectively, whereas those of PPAR-α and CPT-1a were 16% and 65% lower (P < 0.05), respectively, with a significant 62% enhancement in the SREBP-1c/PPAR-α ratio. Liver n-3 LCPUFA levels were 53% lower in obese patients who also showed IR and hipoadiponectinemia over controls (P < 0.05). IR negatively correlated with both the hepatic content of n-3 LCPUFA (r = ? 0.55; P < 0.01) and the plasma levels of adiponectin (r = ? 0.62; P < 0.005). Liver SREBP-1c/PPAR-α ratio and n-3 LCPUFA showed a negative correlation (r = ? 0.48; P < 0.02) and positive associations with either HOMA (r = 0.75; P < 0.0001) or serum insulin levels (r = 0.69; P < 0.001). In conclusion, liver up-regulation of SREBP-1c and down-regulation of PPAR-α occur in obese patients, with enhancement in the SREBP-1c/PPAR-α ratio associated with n-3 LCPUFA depletion and IR, a condition that may favor lipogenesis over FA oxidation thereby leading to steatosis.     

Zinc and glycemic control: A meta-analysis of randomised placebo controlled supplementation trials in humans

BackgroundImpaired zinc metabolism is prominent in chronic disorders including cardiovascular disease and diabetes. Zinc has the potential to affect glucose homeostasis in animals and humans and hence impact the risk of type 2 diabetes mellitus.MethodsA systematic review and meta-analysis of randomised placebo controlled trials was conducted to determine the effect of zinc supplementation on fasting blood glucose, HbA1c, serum insulin and serum zinc concentrations. Relevant studies for inclusion were identified from a literature search of electronic databases up to July 2011.ResultsFourteen reports (n = 3978 subjects) were included in the meta-analysis. In the overall analysis, a small but statistically significant reduction in fasting glucose concentrations was observed (?0.19 ± 0.08 mmol/L, P = 0.013) after zinc supplementation. HbA1c tended to decrease in zinc-supplemented individuals (?0.64 ± 0.36%, P = 0.072). No significant effect was observed for serum insulin concentrations. Plasma zinc concentrations increased significantly following supplementation (+4.03 ± 0.81 μmol/L, P = 0.001). In secondary analyses of participants with chronic metabolic disease (types 1 and 2 diabetes mellitus, metabolic syndrome and obesity), zinc supplementation produced a greater reduction in glucose concentrations (?0.49 ± 0.11 mmol/L, P = 0.001) compared to the effect that was observed in healthy participants.ConclusionThe significant albeit modest reduction in glucose concentrations and tendency for a decrease in HbA1c following zinc supplementation suggest that zinc may contribute to the management of hyperglycemia in individuals with chronic metabolic disease.