Effect of lifestyle modification on adipokine levels in obese subjects with insulin resistance

Associations of physical activity with inflammatory factors, adipocytokines, and metabolic syndrome in middle-aged and older chinese people

BACKGROUND

Inflammatory factors, adipocytokines, and the metabolic syndrome are important determinants of cardiometabolic disease. It remains unclear how physical activity is related to these risk factors. Our objective was to investigate single and joint associations of physical activity with inflammatory factors, adipocytokines, and the metabolic syndrome among middle-aged and older Chinese people.

METHODS AND RESULTS

A total of 3289 individuals (1458 men, 1831 women) 50 to 70 years of age participated in a population-based cross-sectional survey in Beijing and Shanghai, China. Levels of total physical activity were assessed with the International Physical Activity Questionnaire. High-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-alpha receptor 2, adiponectin, and retinol-binding protein 4 were measured. The metabolic syndrome was defined using the updated National Cholesterol Education Program/Adult Treatment Panel III criteria for Asian Americans. Plasma concentrations of high-sensitivity C-reactive protein were 1.58, 1.74, and 1.27 mg/L (P=0.0138) and of adiponectin were 16.12, 16.20, and 17.21 mg/L (P=0.0078) among individuals with low, medium, and high levels of total physical activity, respectively, with adjustment for potential confounders. In the multivariable-adjusted logistic regression analyses, participants with higher levels of total physical activity had a lower risk of having the metabolic syndrome (odds ratio, 0.68; 95% confidence interval, 0.54 to 0.85; P for trend=0.001) compared with those with lower levels.

CONCLUSIONS

Being physically active is associated with a better profile of inflammatory factors and adipocytokines and a reduced risk of having the metabolic syndrome among Chinese people.

Update on therapeutic strategies to increase adiponectin function and secretion in metabolic syndrome

Changes in diagnostic criteria have impacted on the definition of the metabolic syndrome. The central aetiological importance of insulin resistance has lessened, while the role of other cardiovascular risk factors has progressively increased. Inflammatory mediators have also been identified as crucial targets for more selective therapies in metabolic syndrome. Among several pro-inflammatory factors, adiponectin has been shown to be associated with reduced cardiovascular risk in metabolic syndrome patients. Here, we review new therapeutic approaches, which could potentially increase adiponectin levels in metabolic syndrome.

The STEDMAN project: biophysical, biochemical and metabolic effects of a behavioral weight loss intervention during weight loss, maintenance, and regain

The Study of the Effects of Diet on Metabolism and Nutrition (STEDMAN) Project uses comprehensive metabolic profiling to probe biochemical mechanisms of weight loss in humans. Measurements at baseline, 2 and 4 weeks, 6 and 12 months included diet, body composition, metabolic rate, hormones, and 80 intermediary metabolites measured by mass spectrometry. In 27 obese adults in a behavioral weight loss intervention, median weight decreased 13.9 lb over the first 6 months, then reverted towards baseline by 12 months. Insulin resistance (HOMA) was partially ameliorated in the first 6 months and showed sustained improvement at 12 months despite weight regain. Ghrelin increased with weight loss and reverted to baseline, whereas leptin and PYY fell at 6 months and remained persistently low. NPY levels did not change. Factors possibly contributing to sustained improvement in insulin sensitivity despite weight regain include adiponectin (increased by 12 months), IGF-1 (increased during weight loss and continued to increase during weight regain), and visceral fat (fell at 6 months but did not change thereafter). We observed a persistent reduction in free fatty acids, branched chain amino acids, and related metabolites that may contribute to improved insulin action. These findings provide evidence for sustained benefits of weight loss in obese humans and insights into mechanisms.

The association between adherence to the Mediterranean diet and adiponectin levels among healthy adults: the ATTICA study

Adiponectin is thought to exert anti-inflammatory actions. The aim of the present work was to evaluate the association of long-term adherence to the Mediterranean diet with adiponectin levels, in a sample of cardiovascular disease-free adults. In a random sub-sample of "ATTICA" study, 532 men and women, serum adiponectin was measured. Among several sociodemographic, clinical and biological factors, adherence to the Mediterranean diet was assessed by a special diet score (MedDietSCore) that incorporated the inherent characteristics of this traditional diet. Unadjusted analysis revealed that participants who were in the highest tertile of the diet score had an average 41% higher adiponectin levels, as compared to those who were in the lowest tertile (P<.001). Multiadjusted data analysis showed that compared to the highest tertile of diet score, participants in the middle or the lowest one had an average 0.99+/-0.22 (P=.001) and 1.05+/-0.27 microg/ml (P=.001) lower adiponectin levels after adjusting for age, sex and various bioclinical factors. Adherence to the Mediterranean diet was associated with an increase on adiponectin levels. This finding may partially explain beneficial effects of this traditional healthy diet on the cardiovascular system.

Influence of G308A promoter variant of tumor necrosis factor-alpha gene on insulin resistance and weight loss secondary to two hypocaloric diets: a randomized clinical trial

BACKGROUND AND AIMS

The aim of our study was to investigate the influence of G-308A promoter variant in the TNF-alpha gene on insulin resistance and weight loss secondary to two hypocaloric diets.

METHODS

Two hundred and three obese, nondiabetic patients were analyzed. Before and after 2 months of two hypocaloric diets, a nutritional evaluation and a blood analysis were performed. Statistical analysis was performed for the combined G308A and A-308A as mutant group and type G-308G as wild-type (WT) group.

RESULTS

Two hundred and three patients were enrolled; 154 patients (75.5%) had the genotype G-308G and 49 patients (24.5%) had the genotype G-308A. With diet Type I and in the WT group, body mass index (BMI), weight, fat mass (FM), systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, insulin, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) concentrations decreased. In the mutant group, BMI, weight and FM decreased. In the WT group with Type II diet, BMI, weight, FM, SBP, TC, and insulin concentrations decreased. In the mutant group, BMI, weight and FM decreased. Only leptin concentrations showed a significant decrease in the WT group with both diets (diet I: 15.6%, p <0.05 and diet II: 28.3%, p <0.05).

CONCLUSIONS

Carriers of G-308G promoter variant of TNF-alpha gene have a better metabolic response than A-308 obese patients with both diets.

Plasma adiponectin concentrations are associated with body composition and plant-based dietary factors in female twins

Circulating adiponectin is emerging as an important link between obesity, type 2 diabetes, and cardiovascular disease (CVD). However, the spectrum of lifestyle factors that modulate the adiponectin concentration remains to be elucidated, particularly among women. We conducted a cross-sectional study of 877 female twin pairs from the TwinsUK adult twin registry. Using a co-twin design, we examined dietary and body composition influences on adiponectin by conducting matched, within-pair analyses to eliminate confounding. Following multivariable adjustment within-twin pairs, significant influences on adiponectin (log-transformed, percent change per SD of the dietary/body composition variable) were observed for nonstarch polysaccharides (3.25%; 95% CI: 0.06, 6.54; P < 0.05) and magnesium intake (3.80%; 95%CI: 0.17, 7.57; P < 0.05), with a trend toward an association for fruit and vegetable (F&V) intakes (2.55%; 95% CI: -0.26, 5.45; P = 0.08). These modest positive associations cannot be explained by confounding through other lifestyle factors shared by the twins. A significant relationship between adiponectin and 3 derived dietary patterns (F&V, dieting, traditional English), carbohydrate, protein, trans fat, and alcohol intake was also observed. Strong inverse associations with adiponectin were observed for BMI (-10.72%; 95% CI: -13.78, -7.55), total (-6.89%: 95% CI: -10.34, -3.30; P < 0.05), and central fat mass (-12.50%; 95% CI: -15.82, -9.05; P < 0.05); these relationships were significant both when twins were analyzed as individuals and when characteristics were contrasted within-twin pairs, suggesting a direct effect. We observed modest associations between dietary factors and adiponectin in female twins, independent of adiposity, and report strong inverse associations with body composition. These data reinforce the importance of weight maintenance and increasing consumption of diets rich in plant-based foods to prevent CVD and type 2 diabetes.

Role of visceral adipose tissue in aging

BACKGROUND

Visceral fat (VF) accretion is a hallmark of aging in humans. Epidemiologic studies have implicated abdominal obesity as a major risk factor for insulin resistance, type 2 diabetes, cardiovascular disease, metabolic syndrome and death.

METHODS

Studies utilizing novel rodent models of visceral obesity and surgical strategies in humans have been undertaken to determine if subcutaneous (SC) abdominal or VF are causally linked to age-related diseases.

RESULTS

Specific depletion or expansion of the VF depot using genetic or surgical tools in rodents has been shown to have direct effects on disease risk. In contrast, surgically removing large quantities of SC fat does not consistently improve metabolic parameters in humans or rodents, while benefits were observed with SC fat expansion in mice, suggesting that SC fat accrual is not an important contributor to metabolic decline. There is also compelling evidence in humans that abdominal obesity is a stronger risk factor for mortality risk than general obesity. Likewise, we have shown that surgical removal of VF improves mean and maximum lifespan in rats, providing the first causal evidence that VF depletion may be an important underlying cause of improved lifespan with caloric restriction.

GENERAL SIGNIFICANCE

This review provides both corollary and causal evidence for the importance of accounting for body fat distribution, and specifically VF, when assessing disease and mortality risk. Given the hazards of VF accumulation on health, treatment strategies aimed at selectively depleting VF should be considered as a viable tool to effectively reduce disease risk in humans.

Effect of diet on the low-grade and chronic inflammation associated with obesity and metabolic syndrome

Adipose tissue is an active endocrine and paracrine organ that releases a large number of cytokines and biomarkers, which are involved in the development of chronic diseases. These effects have been attributed to direct or indirect mechanisms acting on insulin resistance, inflammation and endothelial dysfunction. In addition, the expression and secretion of these biomarkers in various tissues can be influenced by dietary patterns, with an effect on inflammatory status. In this context, following an energy-balanced diet, moderate in carbohydrates, high in oleic and omega-3 fatty acids, and low in saturated and trans fatty acids, with high intake of fruits and legumes and moderate alcohol consumption, appears to have beneficial effects on the inflammatory state associated with obesity and the manifestations of metabolic syndrome. However, the long-term impact of habitual intake and the mechanisms involved in distinct physiological and pathological conditions remain unclear.

Metabolic syndrome

Hirsutism is a finding that can lead to subsequent metabolic diagnoses such as the metabolic syndrome. Metabolic syndrome describes a cluster of cardiometabolic risk factors associated with overweight and obesity. Although it has been the subject of some controversy, perhaps due to the many definitions proposed by different health organizations, metabolic syndrome is clinically relevant in that it is a predictor of vascular risk, even independent of any associated type 2 diabetes. While various definitions may differ in precise cut-off points, they uniformly emphasize key pathophysiologic processes: visceral obesity, dyslipidemia, insulin resistance, and hypertension. Management of metabolic syndrome focuses on methods of reducing the component risk factors, and therapies thus target the above processes as well as controlling inflammation and the prothrombotic state. Treatments can include not only pharmacologic approaches but behavior modification as well.

Inverse association between serum resistin and insulin resistance in humans

AIM

To determine how serum concentrations of resistin are distributed in humans in relation to insulin resistance, type 2 diabetes, and obesity.

METHODS

Cross-sectional, descriptive study carried out in a random sample (n=713, 43% men, 18-75 years) of general population of inhabitants of the Canary Islands (Spain). Serum resistin concentration, HOMA2-IR, anthropometric parameters, drug consumption and physical activity were recorded.

RESULTS

There were no differences in resistin concentration between participants with and without diabetes (3.1+/-0.2 vs. 3.2+/-0.1ng/mL; p=0.566), or between obese and non-obese participants (3.1+/-0.1 vs. 3.2+/-0.1ng/mL; p=0.803). Individuals with abdominal obesity (waist-hip ratio [WHR] >or=1 in men or >or=0.9 in women) had lower concentrations of resistin (3.0+/-0.13 vs. 3.4+/-0.1ng/mL; p<0.001). The correlations between resistin and HOMA2-IR (r=-0.231; p<0.001) and between resistin and WHR (r=-0.202; p<0.001) were inverse. Multivariate analysis corroborated the inverse association of this cytokine with HOMA2-IR, WHR and, in women, also retained in the model the direct association between resistin and physical activity and the inverse association between resistin and antihypertensive agents.

CONCLUSIONS

In this population resistin is inversely associated with insulin resistance and abdominal obesity.

Adherence to healthy eating patterns is associated with higher circulating total and high-molecular-weight adiponectin and lower resistin concentrations in women from the Nurses' Health Study

BACKGROUND

Adherence to a healthy dietary pattern, such as the Alternate Healthy Eating Index (AHEI), is associated with a lower risk of diabetes and atherosclerosis.

OBJECTIVE

We aimed to determine whether adherence to the AHEI is associated with higher plasma total and high-molecular-weight (HMW) adiponectin concentrations and lower concentrations of resistin, as well as biomarkers of inflammation, endothelial dysfunction, and insulin resistance.

DESIGN

The study evaluated 1922 women from the Nurses' Health Study (62% of whom were overweight) who had no history of diabetes or cardiovascular disease. Their plasma biomarker concentrations were measured in 1990, and data on dietary intake from semiquantitative food-frequency questionnaires administered in 1984, 1986, and 1990 were averaged to account for long-term dietary exposure and to reduce within-subject variability.

RESULTS

After adjustment for age and energy intake, women with the highest adherence to the AHEI had 24% higher median total adiponectin and 32% higher median HMW adiponectin concentrations, as well as 16% lower resistin, 41% lower CRP, 19% lower sE-selectin, and 24% lower ferritin concentrations (P < 0.01 for all) than did women with the lowest adherence to the AHEI. These associations remained significant after adjustment for potential confounders. Inverse associations between the AHEI and soluble tumor necrosis factor-alpha receptor II, interleukin-6, soluble intercellular adhesion molecule 1, soluble vascular cell adhesion molecule 1, C-peptide, insulin, and glycated hemoglobin were evident, but they were not significant after adjustment for body mass index.

CONCLUSION

The preventive effects of healthier dietary patterns on risk for diabetes and atherosclerosis may be mediated by improvements in plasma concentrations of adipokines or other biomarkers of risk for diabetes and cardiovascular disease.

Endogenous adipose-derived factors diminish coronary endothelial function via inhibition of nitric oxide synthase

Adipocytokines may be the molecular link between obesity and vascular disease. However, the effects of these factors on coronary vascular function have not been discerned. Accordingly, the goal of this investigation was to delineate the mechanisms by which endogenous adipose-derived factors affect coronary vascular endothelial function. Both isolated canine coronary arteries and coronary blood flow in anesthetized dogs were studied with and without exposure to adipose tissue. Infusion of adipose-conditioned buffer directly into the coronary circulation did not change baseline hemodynamics; however, endothelial-dependent vasodilation to bradykinin was impaired both in vitro and in vivo. Coronary vasodilation to sodium nitroprusside was unaltered by adipose tissue. Oxygen radical formation did not cause the impairment because quantified dihydroethidium staining was decreased by adipose tissue and neither a superoxide dismutase mimetic nor catalase improved endothelial function. Inhibition of nitric oxide (NO) synthase with L-NAME diminished bradykinin-mediated relaxations and eliminated the subsequent vascular effects of adipose tissue. In vitro measurement of NO demonstrated that adipose tissue exposure quickly lowered baseline NO and abolished bradykinin-induced NO production. The results indicate that adipose tissue releases factor(s) that selectively impair endothelial-dependent dilation via inhibition of NO synthase-mediated NO production.

The Why WAIT program: improving clinical outcomes through weight management in type 2 diabetes

Targeting body weight, as an alternative model to targeting hemoglobin A(1c), is emerging as a viable and potentially cost-effective approach to diabetes management in clinical practice. Why WAIT (Weight Achievement and Intensive Treatment) is a 12-week multidisciplinary program for weight control and intensive diabetes management specifically designed for application in routine diabetes practice. The program, which is generally covered by insurance, is followed by continuous support aimed at long-term maintenance of weight loss and diabetes control. This model was effective in improving key metabolic abnormalities observed in diabetic patients. Eighty-two percent of participants achieved the target hemoglobin A(1c) of less than 7% on less diabetes medications. The achieved weight reduction after 12 weeks of intervention was maintained for an additional year. Future dissemination of this intervention model in routine clinical practice may require wider endorsement by third-party payers and support of governmental health care agencies to halt the progression of the epidemic of obesity and diabetes in the United States.

Influence of Ala54Thr polymorphism of fatty acid-binding protein 2 on weight loss and insulin levels secondary to two hypocaloric diets: a randomized clinical trial

OBJECTIVE

A transition G to A at codon 54 of FABP2 was associated with high insulin resistance and different dietary response. The aim of our study was to investigate the influence of this polymorphism on weight loss and metabolic changes secondary to two hypocaloric diets.

SUBJECTS AND METHODS

A sample of 204 obesity patients was analyzed. Before and after 2 months of hypocaloric diet, a nutritional evaluation was performed. Patients were randomly allocated to diet I (low-fat diet) or II (low carbohydrate diet).

RESULTS

With diet Type I and in the wild group (Ala54/Ala54), BMI, weight, fat mass, waist circumference, waist to hip ratio, systolic and diastolic blood pressures, total cholesterol, triglyceride and insulin levels decreased. In the mutant group (Ala54/Thr54 and Thr54/Thr54), BMI, weight, waist circumference and fat mass decreased. In the wild group with diet Type II, the same parameters that group I decreased and glucose levels, too. In the mutant group, BMI, weight, waist circumference and fat mass decreased. Only leptin levels have a significant decrease in the wild group with both diets (diet I: 30.7%; p<0.05 and diet II: 15.85%; p<0.05).

CONCLUSION

Similar weight loss is associated with different changes, depending on the FABP genotype with both diets. Weight loss is associated with a more deep decrease in serum leptin concentration with low-fat diet.

Adipokines and the prediction of the accumulation of cardiovascular risk factors or the presence of metabolic syndrome in elementary school children

BACKGROUND

Information is limited about how adipokines predict the accumulation of cardiovascular (CV) risk factors or the presence of metabolic syndrome (MS) in children.

METHODS AND RESULTS

The subjects were 321 children (200 boys and 121 girls; 109 normal and 212 obese) aged 6-12 years. Obesity was defined as a body mass index of >or= the 95(th) percentile for age and sex. MS was defined by using the newly established Task Force criteria. The levels of the adipokines--adiponectin, leptin, ghrelin, high sensitive C-reactive protein (CRP) and resistin--were measured. Regression analyses revealed that high leptin levels were predictive of the accumulation of CV risk factors in normal weight, obese, and entire (normal weight and obese) group of subjects. High CRP in the normal weight group and low adiponectin in the obese and the entire groups were also independently predictive of the accumulation of risk factors. A high leptin level was solely predictive of the presence of MS in obese and entire groups.

CONCLUSIONS

Leptin was the most sensitive marker for predicting the accumulation of CV risk factors and the presence of MS in elementary school children. Primary prevention is important because both leptin and adiponectin levels abruptly worsened when children obtained any 1 risk factor.

The usefulness of circulating adipokine levels for the assessment of obesity-related health problems

Because the prevalence of obesity has increased dramatically in recent years, one of the key targets of public health is obesity and its associated pathological conditions. Obesity occurs as a result of white adipose tissue enlargement, caused by adipocyte hyperplasia and/or hypertrophy. Recently, endocrine aspects of adipose tissue have become an active research area and these adipose tissue-derived factors are referred to as adipokines. These adipokines interact with a range of processes in many different organ systems and influence a various systemic phenomena. Therefore, dysregulated production of adipokines has been found to participate in the development of metabolic and vascular diseases related to obesity. The obese state is also known to be associated with increased local and systemic inflammation. Adipokines influence not only systemic insulin resistance and have pathophysiological roles in the metabolic syndrome and cardiovascular disease, but also contribute toward an increase in local and systemic inflammation. Thus, circulating levels of adipokines can be used as high-throughput biomarkers to assess the obesity-related health problems, including low grade inflammation. This review focuses on the usefulness of measuring circulating adipokine levels for the assessment of obesity-related health problems.

Influence of Lys656Asn polymorphism of leptin receptor gene on leptin response secondary to two hypocaloric diets: a randomized clinical trial

BACKGROUND

Human obesity is characterized by high levels of leptin, and it has been suggested that obese patients may be leptin-resistant.

OBJECTIVE

The aim of our study was to investigate the influence of Lys656Asn polymorphism in the LEPR gene on leptin response secondary to a low fat versus a low carbohydrate diet in obese patients.

DESIGN

A population of 78 obesity patients was enrolled. Before and after 2 months of two diets, a nutritional evaluation was performed.

RESULTS

52 patients had genotype Lys656/Lys656 (wild group) and 26 patients Lys656/Asn656 or Asn656/Asn656 (mutant group). In the low fat and wild groups, BMI, weight, fat mass, glucose, total cholesterol, triglyceride, insulin, and blood pressure decreased. In mutant type (MT), BMI, weight and fat mass decreased. In wild type (WT) with low carbohydrate diet, BMI, weight, fat mass, waist circumference, waist-to-hip ratio, total cholesterol, and blood pressures decreased. In MT, BMI, weight and fat mass decreased. Only leptin concentrations have a significant decrease in WT with both diets (diet I: 30.3%; p < 0.05) and (diet II: 15.5%; p < 0.05).

CONCLUSION

In WT patients, the changes in serum leptin concentration due to 2 months' intervention with low fat are higher than with a low carbohydrate diet.

How cytokines can influence the brain: a role for chemokines?

Following inflammation or infection, cytokines are released in the blood. Besides their effect on the immune system, cytokines can also act in the brain to modulate our behaviors, inducing for example anorexia when produced in large amount. This review focuses on our current knowledge on how cytokines can influence the brain and the behaviors through several possible pathways: modulating peripheral neurons which project to the brain through the vagus nerve, modulating the levels of hormones such as leptin which can act to the brain through the humoral pathway and possibly acting directly in the brain, through the local production of cytokines and chemokines such as SDF-1alpha/CXCL12.

Prospective randomized study for optimal insulin therapy in type 2 diabetic patients with secondary failure

Background

The large clinical trials proved that Basal-Bolus (BB) insulin therapy was effective in the prevention of diabetic complications and their progression. However, BB therapy needs multiple insulin injections per a day. In this regard, a biphasic insulin analogue needs only twice-daily injections, and is able to correct postprandial hyperglycemia. Therefore it may achieve the blood glucose control as same as that of BB therapy and prevent the diabetic complications including macroangiopathy.

Methods

In PROBE (Prospective, Randomized, Open, Blinded-Endpoint) design, forty-two type 2 diabetic patients (male: 73.8%, median(inter quartile range) age: 64.5(56.8~71.0)years) with secondary failure of sulfonylurea (SU) were randomly assigned to BB therapy with a thrice-daily insulin aspart and once-daily basal insulin (BB group) or to conventional therapy with a twice-daily biphasic insulin analogue (30 Mix group), and were followed up for 6 months to compare changes in HbA1c, daily glycemic profile, intima-media thickness (IMT) of carotid artery, adiponectin levels, amounts of insulin used, and QOL between the two groups.

Results

After 6 months, HbA1c was significantly reduced in both groups compared to baseline (30 Mix; 9.3(8.1~11.3) → 7.4(6.9~8.7)%, p < 0.01, vs BB;8.9(7.7~10.0) → 6.9(6.2~7.3)%, p < 0.01), with no significant difference between the groups in percentage change in HbA1c (30 Mix; -14.7(-32.5~-7.5)% vs BB -17.8(-30.1~-11.1)%, p = 0.32). There was a significant decrease in daily glycemic profile at all points except dinner time in both groups compared to baseline. There was a significant increase in the amount of insulin used in the 30 Mix group after treatment compared to baseline (30 Mix;0.30(0.17~0.44) → 0.39(0.31~0.42) IU/kg, p = 0.01). There was no significant difference in IMT, BMI, QOL or adiponectin levels in either group compared to baseline.

Conclusion

Both BB and 30 mix group produced comparable reductions in HbA1c in type 2 diabetic patients with secondary failure. There was no significant change in IMT as an indicator of early atherosclerotic changes between the two groups. The basal-bolus insulin therapy may not be necessarily needed if the type 2 diabetic patients have become secondary failure.

Trial registration

Current Controlled Trials number, NCT00348231

Significance of soluble CD40 ligand, adiponectin and reactive oxygen metabolites in aging

We analyzed the association between platelet activation, adiponectin, insulin resistance and oxidative stress in aging. In addition, we included American football (AB) players to investigate whether this association is modulated by exercise. Eighty-six old age patients (> or = 65 years old) hospitalized at the nursing institution and 62 AB players were recruited as study subjects. Reactive oxygen metabolites (ROM), soluble CD40 ligand (sCD40L) and adiponectin were estimated with these patients. In comparison to old age, plasma adiponectin levels in AB players were significantly low. In addition, the adiponectin values of elder group (> 80 years) in old age were significantly increased higher than those for younger group (< or = 80 years). There were no differences of sCD40L in two groups. Levels of ROM in AB players were also significantly lower than that in old age. However, the ROM values of younger group in old age were significantly increased higher than those for elder group. The sCD40L also exhibited the same results. There were no significant differences in ROM and adiponectin levels between the high homeostasis model assessment-insulin resistance (HOMA-IR) (> 2.0) and the low HOMA-IR (< or = 2.0). In contrast, in the old age, the sCD40L and ROM levels in the high HOMA-IR group were significantly higher than those in the low HOMA-IR group. In addition, the adiponectin level in the high HOMA-IR group was significantly lower than that in the low HOMA-IR group. Our results suggest that platelet activation, adiponectin and oxidative stress are the very important factors for aging, and the maintenance of exercise could prevent the occurrence of metabolic syndrome or insulin resistance.

Inflammation, obesity, and fatty acid metabolism: influence of n-3 polyunsaturated fatty acids on factors contributing to metabolic syndrome

Metabolic syndrome (MetS) comprises an array of metabolic risk factors including abdominal obesity, dyslipidemia, hypertension, and glucose intolerance. Individuals with MetS are at elevated risk for diabetes and cardiovascular disease. Central to the etiology of MetS is an interrelated triad comprising inflammation, abdominal obesity, and aberrations in fatty acid metabolism, coupled with the more recently recognized changes in metabolism during the postprandial period. We review herein preliminary evidence regarding the role of dietary n-3 polyunsaturated fatty acids in modulating each of the components of the triad of adiposity, inflammation, and fatty acid metabolism, with particular attention to the role of the postprandial period as a contributor to the pathophysiology of MetS.

The anti-inflammatory effects of exercise training in patients with type 2 diabetes mellitus

BACKGROUND

Diabetes mellitus (DM) and chronic inflammation are strongly related to increased cardiovascular risk. The purpose of this study was to evaluate whether an aerobic training programme would ameliorate inflammatory and anti-inflammatory markers in patients with type 2 DM.

DESIGN

Interventional study.

METHODS

A total of 60 overweight individuals with type 2 DM, but without vascular complications, were randomly assigned to either a 6-month aerobic exercise training programme (four times/week, 45-60 min/session), designated as exercise group, or to the control group. All participants were on an oral antidiabetic regimen and none was receiving lipid-lowering medications. Anthropometric parameters, cardiorespiratory fitness, glycaemic and lipid profiles, high sensitivity C-reactive protein (hs CRP), adiponectin, interleukin (IL)-10, IL-18, tumour necrosis factor (TNF)-alpha, insulin, reciprocal index of homoeostasis model assessment (HOMA-IR), body fat and blood pressure (BP) were measured at baseline and at the end of the study.

RESULTS

In comparison with baseline and control group, exercise-treated patients improved glucose control, lipid profile, exercise capacity (VO2 peak) and exhibited decreased insulin resistance and systolic BP considerably (P<0.05). Plasma adiponectin, TNF-alpha and body weight changed slightly across treatment (P>0.05), whereas diastolic BP and fat mass tended to decrease (P=0.071 and 0.061, respectively). Exercise training reduced hs CRP (from 0.48+/-0.16 to 0.29+/-0.2 mg/dl; P=0.04) and IL-18 (from 315.19+/-122.76 to 203.77+/-96.02 pg/ml; P=0.02). Moreover, exercise provided anti-inflammatory protection through IL-10 increment (P=0.039) and IL-18/IL-10 ratio downregulation (P=0.014). In multiple regression analysis, alteration in IL-18 was independently correlated with hs CRP and VO2 peak changes (P<0.05).

CONCLUSION

Aerobic exercise training without significant weight loss improves metabolic profile and exerts anti-inflammatory effects in patients with type 2 DM.

Effects of weight loss from a very-low-carbohydrate diet on endothelial function and markers of cardiovascular disease risk in subjects with abdominal obesity

BACKGROUND

The effects of a very-low-carbohydrate, high-saturated-fat weight-loss diet (LC) on brachial artery flow-mediated dilatation (FMD) and markers of endothelial function are unknown.

OBJECTIVE

The effect of an LC on markers of endothelial function and cardiovascular disease (CVD) risk was compared with that of an isocaloric high-carbohydrate, low-saturated-fat diet (HC).

DESIGN

FMD and markers of endothelial function (n = 70) and CVD risk were measured before and after 8 wk of weight loss. Ninety-nine subjects aged 50.0 +/- 8.3 y with a body mass index (in kg/m2) of 33.7 +/- 4.1 completed the study.

RESULTS

Mean (+/-SD) FMD did not change significantly (P = 0.55) with either diet. Pulse wave velocity improved with both diets (P < 0.01). Endothelial markers, E- and P selectin, intracellular and cellular-adhesion molecule-1, tissue-type plasminogen activator, and plasminogen activator inhibitor-1 decreased (P < 0.001), with no diet effect. Adiponectin did not change significantly. More weight (P = 0.05 for diet x time interaction) and more abdominal fat mass (P = 0.05 for diet x time interaction) were lost with the LC than with the HC. LDL cholesterol decreased more with the HC than with the LC (P < 0.05, time x diet), and C-reactive protein decreased more with the HC than with the LC (P < 0.05 for diet x time interaction). Homocysteine increased more with the LC (P < 0.01 for diet x time interaction). Folate decreased with the LC and increased with the HC (P < 0.05, time; P < 0.001 for diet x time interaction).

CONCLUSION

An LC does not impair FMD. We observed beneficial effects of both diets on most of the CVD risk factors measured. This trial was registered with the Australian Clinical Trials Registry as ACTR N0 12606000203550.

[Analysis on the association of physical activity with metabolic syndrome in a population-based study of Japanese-Brazilians]

Sedentary behavior-related diseases can be prevented by lifestyle changes. Part of the cardiovascular benefits of physical activity (PA) may be due to low-grade inflammation. This study describes the PA of a population of Japanese and analyses its association with metabolic syndrome (MS) adjusted a number of variables. This was based on a database previously created following a population-based study of Japanese-Brazilians. 1,330 subjects aged > or = 30 years, of both sexes, living in Bauru, were included and they were submitted to interviews, being obtained sociodemographic, health, physical activity and dietary data, as well as clinical and laboratory data. Physical activity assessment focused on activities during work and leisure times. Diagnosis of MS was based on an adaptation of NCEP criteria for Asians. Non-conditional logistic regression had MS as the dependent variable. Men (46.1%) and women showed similar mean ages (57.0 +/- 12.8 and 56.9 +/- 12.2 years, respectively). A slight preponderance of females was observed. Men had a higher level of education and more frequently were smokers (p< 0.001); their mean values of BMI, waist and blood pressure (p< 0.001) were higher than the womens. For both sexes, the majority referred light and moderate activities (81.2% of men and 86.6% of women). As far as work time is concerned, 87.8% of men classified their effort as light or moderate versus 96.1% of women. Distribution by PA levels showed that women were always less active than men (p= 0.01). Stratifying by the presence of MS, men and women with MS were significantly older and showed greater anthropometric values. Considering the walking duration for work, there was a tendency of shorter periods among those with MS (p< 0.078). As expected, subjects with MS showed significantly higher levels of blood pressure, plasma glucose, lipids and HOMA-IR when compared to those without MS. HDL levels were lower in the MS group, being significant for the female sex. The mean values of CRP were higher in subjects with MS. In logistic regression, age, BMI, HOMA-IR and CRP were shown to be independently associated with MS, but not parameters used to measure physical activity. Our findings do not allow to state that physical inactivity is associated with MS in a Japanese-Brazilian population. High frequencies of physical inactivity should have contributed to the negative findings concerning protective effects of physical activity. The association of MS and serum CRP favors the hypothesis that a low-grade inflammatory state may participate in this syndrome.

Gender-based dimorphic pattern for interleukin-1 receptor antagonist in type 2 diabetes mellitus

Adipose tissue secretes a variety of cytokines, some of which are increased in the serum of obese patients. The anti-inflammatory interleukin-1 receptor antagonist (IL-1Ra) is the most highly elevated known cytokine in human obesity, and its serum levels are strongly associated with the degree of insulin resistance in non-diabetic patients.

AIM

The present study examined serum levels of IL-1Ra in type 2 diabetic patients (T2DM) and their relationships with three other adipokines (leptin, interleukin-6 [IL-6], adiponectin). Their correlation with anthropometric and biochemical variables was examined, as well as their intraindividual fluctuations.

METHODS

Fifty T2DM patients, aged 58+/-13 years, were consecutively recruited among those electively hospitalized for a one-week intensive training course with our Diabetes Education Service. Anthropometric measurements and blood samples were taken after an overnight fast on admission (baseline) and after four days.

RESULTS

Mean serum levels of IL-1Ra and leptin, but not of IL-6 and adiponectin, were significantly higher in women than in men (P<0.0006), and this difference persisted after correction for body mass index (BMI) (P<0.0004). In addition, IL-1Ra and leptin were strongly correlated with the BMI (P<0.0004). By contrast, no significant correlations were observed between IL-1Ra and glucose-control parameters. Finally, all four adipokines exhibited wide interindividual variability, but with limited intraindividual fluctuations over the short time period.

CONCLUSION

IL-1Ra, leptin and adiponectin serum levels exhibit marked interindividual variation with high intraindividual consistency. A gender-based dimorphic pattern for IL-1Ra, independent of the degree of adiposity and glucose control, was also found.

Effects of exercise on adipokines and the metabolic syndrome

Adipokines, or adipose tissue-derived cytokines/proteins, may be important factors linking excess adipose tissue to individual metabolic risk factors, and the overall metabolic syndrome. Current evidence supports that aerobic exercise, alone or combined with hypocaloric diet, improves symptoms of the metabolic syndrome, possibly by altering systemic levels of inflammatory adipokines. A number of studies show that increased physical activity leads to lower circulating levels of proinflammatory cytokines and higher levels of adiponectin. However, limited data show that exercise training does not influence adipose tissue adipokine expression or release. Conversely, exercise training may influence cytokine production by circulating mononuclear cells, another important source of elevated inflammation. Future studies are needed to investigate the cellular mechanisms by which exercise training affects inflammation and whether alterations in inflammation are one mechanism by which exercise improves components of the metabolic syndrome in at-risk individuals.

Lifestyle intervention and adipokine levels in subjects at high risk for type 2 diabetes: the Study on Lifestyle intervention and Impaired glucose tolerance Maastricht (SLIM)

OBJECTIVE

We investigated whether circulating adipokine concentrations can be altered by lifestyle intervention according to general recommendations in subjects at risk for diabetes as well as the potential of leptin, adiponectin, and resistin as biomarkers for lifestyle-induced improvements in glucose metabolism and insulin resistance.

RESEARCH DESIGN AND METHODS

In the Study on Lifestyle intervention and Impaired glucose tolerance Maastricht, 147 men and women with impaired glucose tolerance (IGT) were randomized to either a combined diet-and-exercise intervention or a control program. At baseline and after 1 year, an oral glucose tolerance test, an exercise test, and anthropometric measurements were performed. After 1 year, complete data of 103 subjects (50 intervention and 53 control subjects) were obtained.

RESULTS

Lifestyle intervention reduced plasma leptin concentrations (-14.2%) in IGT subjects but did not alter plasma adiponectin (-0.3%) or resistin (-6.5%) concentrations despite marked improvements in glucose tolerance and insulin resistance.

CONCLUSIONS

Changes in leptin concentration were related to improvements in insulin sensitivity independent of changes in body composition.

The effects of physiological and pharmacological weight loss on adiponectin and leptin mRNA levels in the rat epididymal adipose tissue

In subjects with obesity, diabetes and coronary artery disease, circulating levels of leptin increased while that of adiponectin is decreased. In this study we have investigated effects of physiological and pharmacological weight reduction on leptin and adiponectin mRNA expression. Wistar rats were fed either standard laboratory chow for 16 weeks (chow-fed) or given a fat-enriched, glucose-enriched diet (diet-fed) for 8 weeks. After 8 weeks, diet-fed group was subdivided into three subgroups, namely, an untreated obese, or were returned to chow diet, or treated with fenofibrate for further 8 week. After 16 weeks, compared with chow-fed group, diet-fed rats had significantly higher body weight, epididymal fat pad mass, and plasma levels of insulin, leptin, adiponectin, non-esterified fatty acids and triglycerides (P<0.001, for all). Moreover, untreated obese rats had significantly (P<0.01, for both) raised levels of Ob mRNA but reduced adiponectin mRNA levels in epididymal fat pads compared with chow-fed group. These changes were corrected by chronic removal of the high-energy diet and fenofibrate treatment. These findings indicate that physiological or pharmacological lowering of body weight together with circulating plasma lipids play a significant role in leptin and adiponectin synthesis and metabolism.

Effects of long-term exercise and diet intervention on plasma adipokine concentrations

BACKGROUND

In a randomized, controlled, 2 x 2 factorial trial on the effect of long-term changes in diet and exercise, a significant reduction in body weight and fat mass was observed. Alterations in leptin and plasminogen activator inhibitor-1 concentrations were previously reported from this study.

OBJECTIVE

We examined the separate and combined effects of a 1-y exercise and diet intervention on several adipokines; adiponectin, interleukin-6 and -8, tumor necrosis factor-alpha, monocyte chemoattractant protein-1, hepatocyte growth factor, nerve growth factor, C-reactive protein, and resistin.

DESIGN

One hundred eighty-eight men with several risk factors for diabetes and cardiovascular disease were randomly allocated to 4 groups: diet, exercise, combined diet and exercise, and control.

RESULTS

Plasma adiponectin concentrations remained unchanged, whereas body mass index and fat mass decreased after dietary changes and an increase in physical activity. In the control group, adiponectin concentrations were reduced. Analyzed according to the factorial design, only diet intervention had a significant (P = 0.03) positive effect on plasma adiponectin relative to control, and this effect was largely explained by changes in fat mass. After adjustment for change in percentage body fat, there were significant positive effects on tumor necrosis factor-alpha in all 3 intervention groups (P = 0.01 for the diet group, 0.03 for the exercise group, and 0.05 for the combined diet and exercise group). Minor changes were observed for the other adipokines. Neither baseline concentrations of nor changes in adiponectin and plasminogen activator inhibitor-1 were significantly correlated to the other adipokines, whereas concentrations of and changes in the other adipokines were significantly correlated.

CONCLUSION

Diet intervention had a significant positive effect on adiponectin concentrations, which is largely explained by a reduction in fat mass.

Circulating adiponectin and adiponectin receptor expression in skeletal muscle: effects of exercise

Excess visceral fat can regulate insulin sensitivity and energy metabolism by releasing adipokines into the circulation which then bind with their cognate receptors in various tissues and alter glucose and lipid metabolism. Circulating levels of adiponectin, which promotes glucose uptake into skeletal muscle and increases fat oxidation rates, are decreased in obesity. Strategies to enhance the insulin-like and insulin-sensitizing actions of adiponectin have been shown to be effective in improving metabolic abnormalities associated with obesity and diabetes. Interestingly, the insulin-sensitizing effects of exercise have similar metabolic effects as adiponectin in that exercise also promotes glucose uptake into muscle and increases rates of fatty acid oxidation. Recent studies have begun to examine the potential role of adiponectin in mediating the insulin-sensitizing action of exercise by investigating changes in plasma adiponectin levels and tissue-specific adiponectin receptor (AdipoR) expression. In this review, we have summarized the key findings to date which suggest that changes in expression of AdipoR isoforms in skeletal muscle, rather than circulating total adiponectin levels, may be of physiological importance.

Creatine monohydrate and conjugated linoleic acid improve strength and body composition following resistance exercise in older adults

Aging is associated with lower muscle mass and an increase in body fat. We examined whether creatine monohydrate (CrM) and conjugated linoleic acid (CLA) could enhance strength gains and improve body composition (i.e., increase fat-free mass (FFM); decrease body fat) following resistance exercise training in older adults (>65 y). Men (N = 19) and women (N = 20) completed six months of resistance exercise training with CrM (5g/d)+CLA (6g/d) or placebo with randomized, double blind, allocation. Outcomes included: strength and muscular endurance, functional tasks, body composition (DEXA scan), blood tests (lipids, liver function, CK, glucose, systemic inflammation markers (IL-6, C-reactive protein)), urinary markers of compliance (creatine/creatinine), oxidative stress (8-OH-2dG, 8-isoP) and bone resorption (Ν-telopeptides). Exercise training improved all measurements of functional capacity (P<0.05) and strength (P<0.001), with greater improvement for the CrM+CLA group in most measurements of muscular endurance, isokinetic knee extension strength, FFM, and lower fat mass (P<0.05). Plasma creatinine (P<0.05), but not creatinine clearance, increased for CrM+CLA, with no changes in serum CK activity or liver function tests. Together, this data confirms that supervised resistance exercise training is safe and effective for increasing strength in older adults and that a combination of CrM and CLA can enhance some of the beneficial effects of training over a six-month period. Trial Registration. ClinicalTrials.gov NCT00473902

Efeitos do exercício físico sobre o estado redox cerebral

A atividade física é conhecida por promover saúde e bem-estar. O exercício também é responsável por aumentar a produção de Espécies Reativas de Oxigênio (ERO) pelo acréscimo do consumo de oxigênio mitocondrial nos tecidos. O desequilíbrio entre a produção de EROs e as defesas oxidantes dos tecidos pode provocar danos oxidativos a proteínas, lipídios e DNA. O dano oxidativo cerebral é um mecanismo etiopatológico comum da apoptose e da neurodegeneração. O fator de crescimento cérebro-derivado desempenha um importante papel neste contexto. Nesta revisão, apresentamos os resultados de diferentes modelos de exercício físico no metabolismo oxidativo e neurotrófico do Sistema Nervoso Central (SNC). Também revisamos estudos que utilizaram suplementação antioxidante para prevenir danos oxidativos exercício-induzido ao SNC. Os modelos de exercício físico mais comuns foram as rodas de correr, a natação e a esteira com configurações de treinamento muito diferentes como a duração e a intensidade. Os resultados do treinamento físico no tecido cerebral são muito controversos, mas geralmente demonstram ganhos na plasticidade sináptica e na função cognitiva com exercícios de intensidade moderada e baixa.

The potential anti-inflammatory benefits of improving physical fitness in hypertension

Hypertension is associated with an increased risk of stroke and atherosclerosis. In addition to elevated blood pressure, hypertension is characterized by neuroendocrine and immune activation, including elevated levels of C-reactive protein, inflammatory cytokines, and soluble adhesion molecules, which are predictive of morbidity and mortality outcomes. Pharmacological treatment for hypertension reduces blood pressure, but has limited effectiveness in reducing the accompanying inflammation and its associated morbidity and mortality. Exercise and diet interventions regularly show reductions in blood pressure in hypertensive individuals. Similar interventions in other populations show reductions in many inflammatory markers, but these effects have not been routinely examined in hypertensive individuals. The mechanisms through which exercise might exert an anti-inflammatory action include the sympathetic nervous system, the hypothalamic-pituitary-adrenal axis, as well as direct effects of blood pressure. Here, exercise is promoted as a potentially effective treatment for both the elevated blood pressure and chronic inflammation found in hypertension.

Leptin Induces C-Reactive Protein Expression in Vascular Endothelial Cells

OBJECTIVE

There is increasing evidence of an association between leptin and increased cardiovascular risk. Higher leptin levels are associated with increased levels of C-reactive protein (CRP), which itself elicits proatherogenic effects in the vascular endothelium. We tested the hypothesis that leptin induces CRP expression in human coronary artery endothelial cells (HCAECs).

METHODS AND RESULTS

We confirmed the presence of both long and short isoforms of the leptin receptor in cultured HCAECs. Leptin but not IFNalphaA/D nor tumor necrosis factor (TNF) alpha, induced expression of CRP. A dose dependent increase of CRP mRNA and protein was observed with increasing concentration of leptin (0 to 400 ng/mL). This increased CRP expression was attenuated in the presence of anti-leptin receptor antibodies and also by inhibition of ERK1/2 by PD98059 (20 to 40 micromol/L). Time (0 to 60 minutes) and leptin concentration (0 to 200 ng/mL)-dependence of ERK1/2 phosphorylation were evident in response to leptin treatment. Leptin also elicited ROS generation. Inhibition of ROS by catalase (200 microg/mL) prevented ERK1/2 phosphorylation and CRP mRNA transcription.

CONCLUSION

Leptin induces CRP expression in HCAECs via activation of the leptin receptor, increased ROS production, and phosphorylation of ERK1/2. These studies suggest a mechanism for the proatherogenic effects of leptin.

Rosiglitazone decreases serum bone-specific alkaline phosphatase activity in postmenopausal diabetic women

OBJECTIVES

Our objectives were to evaluate the effect of rosiglitazone on bone metabolism and to assess the association between changes in bone turnover parameters and plasma cytokine levels in postmenopausal diabetic women.

DESIGN

This was a 12-wk open-label randomized-controlled trial.

PATIENTS OR OTHER PARTICIPANTS

A total of 56 obese postmenopausal women with newly diagnosed diabetes and 26 nondiabetic healthy controls matched for age and body mass index were included in the study.

INTERVENTIONS

The subjects were instructed to follow a weight-maintenance diet. Half were randomly assigned to receive rosiglitazone 4 mg/d, and the other half remained on diet alone.

MAIN OUTCOME MEASURES

Before and after the interventions, metabolic bone markers and serum cytokine levels were assessed.

RESULTS

Serum total alkaline phosphatase (ALP) and bone-specific ALP levels were statistically significantly lower 12 wk after initiation of rosiglitazone treatment. There were no statistically significant changes in osteocalcin levels among the three groups or in deoxypyridinoline levels in the rosiglitazone group. At the end of 12 wk, all patients had statistically significantly decreased IL-1beta and TNF-alpha levels compared with baseline. Changes in bone-specific ALP levels showed a moderate negative correlation with the changes in the TNF-alpha levels after rosiglitazone treatment and after diet in the diabetic control group.

CONCLUSIONS

Rosiglitazone use is associated with reduced bone formation at earlier stages in postmenopausal diabetic women. The cytokine-lowering effects of rosiglitazone and lifestyle changes could reverse the early inhibitory effect of rosiglitazone therapy on bone formation. Further studies will clarify the long-term effects of rosiglitazone therapy on bone loss and fracture.

In the absence of weight loss, exercise training does not improve adipokines or oxidative stress in overweight children

The aim of the present study was to examine the effect of exercise training on adipokines, inflammatory markers, and oxidative stress in overweight children. Nineteen overweight children were randomly assigned to an aerobic exercise training or sedentary control group for 8 weeks. Measurements included peak oxygen uptake (V o(2)max), body weight and composition, adipokines (C-reactive protein, interleukin 6, tumor necrosis factor alpha, adiponectin, leptin, and resistin), and oxidative stress (8-isoprostane). There were no differences between groups for change in body weight or composition over the 8 weeks. Exercise training improved V o(2)max (exercise group, 1.64 +/- 0.13 to 1.85 +/- 0.17L/min vs control group, 1.83 +/- 0.12 to 1.60 +/- 0.13 L/min, P < .05) but did not change any of the measured adipokines or the marker of systemic oxidative stress, 8-isoprostane. These data suggest that in the absence of weight loss, exercise training alone does not improve the adipokine profile or levels of oxidative stress in overweight children.

Effects of diet with or without exercise on leptin and anticoagulation proteins levels in obesity

Obesity is a risk factor for cardiovascular disease and thromboembolic events. We investigated the effects of weight reduction by a 12-week calorie-restricted diet with or without aerobic exercise (diet group and diet plus exercise group) on leptin and anticoagulation proteins levels. Forty-two obese nondiabetic individuals were evaluated for blood levels of leptin, protein C activity, free protein S antigen and for body fat area calculated on computerized tomography before and after intervention. Before intervention, serum levels of leptin and free protein S antigen correlated positively with several adiposity-related parameters. After the program, body weight and fat area were significantly decreased in both groups. Body mass index and leptin levels decreased in both groups, with a larger change in the diet plus exercise group than in the diet group. Although protein C activity levels did not change in both groups, free protein S antigen levels decreased significantly in the diet plus exercise group. In conclusion, the 12-week programs had significant effects on the initial weight reduction and body fat mass, decreasing lepin levels in obese nondiabetic individuals. To clarify whether aerobic exercise has additional or direct effects on the anticoagulation system, a study in a large number of individuals is needed.

Lifestyle plus Exercise Intervention Improves Metabolic Syndrome Markers without Change in Adiponectin in Obese Girls

BACKGROUND/AIMS

Little is known about whether lifestyle plus exercise intervention improves obesity, metabolic syndrome markers, and circulating adiponectin concentrations in obese girls. The goal of this study was to investigate the effects of a 12-week lifestyle plus exercise intervention on adiponectin and metabolic syndrome markers in Korean obese adolescents.

METHODS

A total of 44 obese adolescent girls (13-15 years old), who were recruited from a local middle school via a flyer or a school newsletter, were randomized to a lifestyle plus exercise intervention group (LIFE+EX, n = 22) or control (CON, n = 22). The LIFE+EX group participated in 12 weeks of lifestyle plus exercise intervention, while the CON group maintained their lifestyle as usual. Body composition, metabolic syndrome markers, and adiponectin were measured prior to and after the intervention program.

RESULTS

Following the 12-week lifestyle plus exercise intervention, group analyses showed significant time x group interactions in changed scores in several of the metabolic syndrome markers such that the LIFE+EX group had significantly greater improvements in body composition including body weight, body mass index, percent body fat, waist circumference, and waist-to-hip ratio than the CON group. Similarly, the LIFE+EX group had significantly greater reductions in SBP, TC, LDLC, TG, TC/HDLC, glucose, insulin, HOMA-IR, CRP, and leptin than the CON group, while there were no significant time x group or time or group differences in DBP, HDLC, HbA1c, and adiponectin.

CONCLUSION

The current findings suggest that lifestyle plus exercise intervention may be an effective means to improve several variables in the health hazards of obesity in Korean adolescent girls, with no change in circulating adiponectin.

Fasting serum insulin and the homeostasis model of insulin resistance (HOMA-IR) in the monitoring of lifestyle interventions in obese persons

OBJECTIVES

Lifestyle changes with increased physical activity and balanced energy intake are recognized as the principal interventions in obesity and insulin resistance. Only few prospective studies, however, have so far addressed the potential role of routine biochemical markers of insulin sensitivity in the monitoring of respective interventions.

DESIGN AND METHODS

Fasting insulin and glucose was measured in 33 obese individuals undergoing a lifestyle modification program (MOBILIS) at baseline and after 1 year. The HOMA-IR index (homeostasis model of insulin resistance) was calculated as [fasting serum glucose*fasting serum insulin/22.5], with lower values indicating a higher degree of insulin sensitivity.

RESULTS

While the median body mass index (BMI) and waist circumference decreased by 10% and 11%, respectively, the HOMA-IR index decreased in an over-proportional manner by 45% within 1 year (BMI baseline, median 35.7, interquartile range (IQR) 33.7-37.7; after 1 year, median 32.2, IQR 29.6-35.1. HOMA-IR baseline, median 2.9, IQR 1.5-4.6; after 1 year 1.6, IQR 0.9-2.7). In contrast to HOMA-IR and fasting serum insulin, no significant changes in fasting serum glucose were observed. Baseline and post-intervention HOMA-IR showed a high degree of inter-individual variation with eight individuals maintaining high HOMA-IR values despite weight loss after 1 year of intervention.

CONCLUSIONS

Individual changes in the carbohydrate metabolism achieved by a lifestyle intervention program were displayed by fasting serum insulin concentrations and the HOMA-IR but not by fasting glucose measurement alone. Therefore, assessment of the HOMA-IR may help to individualize lifestyle interventions in obesity and to objectify improvements in insulin sensitivity after therapeutic lifestyle changes.

Effects of weight loss on a low-carbohydrate diet on flow-mediated dilatation, adhesion molecules and adiponectin

Our aim was to determine whether short-term weight loss on a low-carbohydrate/low-saturated fat diet improved endothelial function compared with a conventional high-carbohydrate diet, as this diet is expected to lower both blood glucose and LDL-cholesterol. In a randomised parallel design of two energy-restricted diets in an outpatient setting, thirty-six subjects (BMI 33 (sem 4) kg/m2) were randomised to a low- or high-carbohydrate diet both low in saturated fat. Flow-mediated dilatation (FMD), fasting glucose, insulin, lipids, adiponectin and adhesion molecules were measured at baseline, during weight loss and at 52 weeks. FMD did not change with either diet (5.2 (sem 0.6) to 5.5 (sem 0.6) %) despite weight loss of 5 % and significant reductions in glucose and insulin and LDL-cholesterol and was not different after sustained weight loss of 5 % at 52 weeks. Adiponectin fell by 6 % at 12 weeks (P = 0.1) with weight loss but rose by 17 % at 12 months (P < 0.05) with 5 % weight loss. There were no effects of diet. In contradistinction, adhesion molecules fell at 12 weeks, vascular cell adhesion molecule-1 by 14 % and intracellular adhesion molecule-1 by 13 % (both P < 0.05). There were correlations between change in adiponectin at 12 months and change in HDL (r 0.778, P < 0.01) and glucose (r - 0.563, P = 0.057). In summary, weight loss does not improve FMD. Novel cardiovascular risk factors improved at 12 weeks but the improvement in adiponectin was delayed.