Leptin and adiponectin in relation to body fat percentage, waist to hip ratio and the apoB/apoA1 ratio in Asian Indian and Caucasian men and women

Effects of male paratroopers' initial body composition on changes in physical performance and recovery during a 20-day winter military field training

Changes in physiological markers and physical performance in relation to paratroopers' initial body composition were investigated during a 20-day winter military field training (MFT) and the subsequent 10-day recovery period. Body composition, serum hormone concentrations and enzymatic biomarkers, and physical performance of 58 soldiers were measured before, during, and after MFT. Comparisons were done according to soldiers' body fat percentage before MFT between low-fat (<12% body fat) and high-fat (>12% body fat) groups. Correlations between body fat percentage preceding MFT and changes in muscle mass, physical performance, and serum hormone concentrations and enzymatic biomarkers were investigated. It was hypothesized that soldiers with a higher fat percentage would have smaller decrements in muscle mass, physical performance, and serum testosterone concentration. The change in muscle and fat mass was different between groups (p < 0.001) as the low-fat group lost 0.8 kg of muscle mass and 2.0 kg of fat mass, while there was no change in muscle mass and a loss of 3.7 kg of fat mass in the high-fat group during MFT. Fat percentage before MFT correlated with the changes in muscle mass (R2 = 0.26, p < 0.001), serum testosterone concentration (R2 = 0.22, p < 0.001), and evacuation test time (R2 = 0.10, p < 0.05) during MFT. The change in muscle mass was correlated with the changes in evacuation test time (R2 = 0.11, p < 0.05) and countermovement jump test results (R2 = 0.13, p < 0.01) during MFT. Soldiers with a higher initial fat percentage lost less muscle mass, and had smaller decrements in some aspects of physical performance, as well as in serum testosterone concentration during MFT.

Modeling tissue co-regulation estimates tissue-specific contributions to disease

Integrative analyses of genome-wide association studies and gene expression data have implicated many disease-critical tissues. However, co-regulation of genetic effects on gene expression across tissues impedes distinguishing biologically causal tissues from tagging tissues. In the present study, we introduce tissue co-regulation score regression (TCSC), which disentangles causal tissues from tagging tissues by regressing gene-disease association statistics (from transcriptome-wide association studies) on tissue co-regulation scores, reflecting correlations of predicted gene expression across genes and tissues. We applied TCSC to 78 diseases/traits (average n = 302,000) and gene expression prediction models for 48 GTEx tissues. TCSC identified 21 causal tissue-trait pairs at a 5% false discovery rate (FDR), including well-established findings, biologically plausible new findings (for example, aorta artery and glaucoma) and increased specificity of known tissue-trait associations (for example, subcutaneous adipose, but not visceral adipose, and high-density lipoprotein). TCSC also identified 17 causal tissue-trait covariance pairs at 5% FDR. In conclusion, TCSC is a precise method for distinguishing causal tissues from tagging tissues.

Growth differentiation factor-15/adiponectin ratio as a potential biomarker for metabolic syndrome in Han Chinese

Aims

Growth differentiation factor-15 (GDF-15) and adiponectin are adipokines that regulate metabolism. This study aimed to evaluate the roles of GDF-15, adiponectin, and GDF-15/adiponectin ratio (G/A ratio) as biomarkers for detecting metabolic syndrome (MS).

Materials and methods

This cross-sectional study included 676 participants aged 20-70 years in Jurong, China. The participants were divided into four groups based on sex and age (<40 and ≥40 years). MS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III criteria. Receiver operating characteristic curves were used to evaluate the performance of GDF-15, adiponectin, and the G/A ratio in predicting MS.

Results

The prevalence of MS was 22.0% (149/676). Logistic regression analysis indicated that the G/A ratio and adiponectin levels, but not GDF-15 levels, were correlated with MS [odds ratio; 95% CI 1.010 (1.006-1.013) and 0.798 (0.735-0.865), respectively] after adjusting for confounding factors. The G/A ratio displayed a significant relationship with MS in each subgroup and with each MS component in both men and women; however, adiponectin concentrations were significantly associated with MS and all its components only in men (all P <0.05). The area under the curve (AUC) of the G/A ratio and the adiponectin level for MS was 0.758 and 0.748, respectively. The highest AUC was 0.757 for the adiponectin level in men and 0.724 for the G/A ratio in women.

Conclusions

This study suggests that the G/A ratio and adiponectin are potential biomarkers for detecting MS in women and men, respectively.

Aerobic Versus Resistance Training: Leptin and Metabolic Parameters Improvement in Type 2 Diabetes Obese Men

Purpose: The purpose of the research was to determine the changes in metabolic parameters, leptin, and irisin levels after aerobic and resistance training in type-2 diabetes obese men. Methods: Forty-five participants in the age range of 17-25 years were randomized into three groups: aerobic training (AT), resistance training (RT), and control (CO). All training sessions were fulfilled 4 days per week for two months. The aerobic training began with intensity of 65% of the maximum aerobic power and finished with 90%. The resistance program started with 50% of one-repetition maximum and reached 70% in the 8th week. Results: Factorial analysis of variance and Bonferroni post-hoc test revealed significant decreases in leptin (p = .043), fasting blood sugar (FBS) (p = .023), insulin (p = .001), homeostasis model assessment for insulin resistance (HOMA-IR) (p = .022) in AT compared with CO and insulin (p = .006) in AT compared with RT. The change of percent body fat (PBF) was positively correlated only with change of HOMA-IR in AT group (p = .032) at p < .05. Conclusion: The result suggests that, compared to resistance training, aerobic training can control metabolic situations such as insulin resistance through the leptin hormone function, and not irisin in type-2 diabetes obese men.

Between-day reliability of cytokines and adipokines for application in research and practice

Purpose: This study assessed the biological reliability of peripheral human cytokines and adipokines, and the influence of participant characteristics on total error. This has essential application to interventional cytokine measurement to ensure that reported results are interpreted with confidence.

Methods: Participants (49% female, 18–85 years, n = 84) completed two consecutive-day testing sessions. Participants provided a venous blood sample at the same time of day across two consecutive days, under standardized participant presentation, including 24-h rested and 12-h fasted conditions. Multiplex immunoassay was used to assess inflammatory analytes from samples (predominantly plasma). Repeat measurements were conducted between-day for total precision quantification, and technical (technique) error was negated from the total to provide an estimate of biological (attributed to participant presentation) error.

Results: Whilst there was no evidence of statistically significant biological error, a small amount of biological error was consistently present across most analytes (∼3.3%/0.07 pg/ml), which was largest for measurement of leptin (7.3%/210 pg/ml). There was also an influence of sex on reliability of leptin and adiponectin (total model explained 6–7% of error variation), where females demonstrated the greatest error.

Conclusion: Biological error reported in this study should be applied to any future study or individual with a repeated measurement of cytokine concentrations over time that maintain best practice procedures (12-h fasted, 24-h rested). In most cases, raw error should be used, with exceptions for women for measurement of leptin and adiponectin. This approach will ensure that results are reported with certainty for improved reporting of intervention efficacy.

Nonobese Male Patients with Alzheimer's Disease Are Vulnerable to Decrease in Plasma Leptin

BACKGROUND

Metabolic dysfunction links to cognitive deficits in Alzheimer's disease (AD). Leptin is an anti-obesity hormone that modulates energy homeostasis and memory function. Although leptin deregulation is implicated in mouse models of AD-like brain pathology, clinical studies have shown inconsistent results regarding an association of leptin with the development of this neurodegenerative disorder.

OBJECTIVE

We investigated the changes of plasma leptin and the correlation of sex-stratified circulating leptin with cognitive performance, AD-related biological markers, and metabolic status in patients with AD and cognitively unimpaired (CU) counterparts.

METHODS

We used nonobese AD patients and CU controls in a University of Kansas Medical Center (KUMC) cohort. Plasma leptin levels, circulating AD-related molecules and metabolic profiles were examined and analyzed.

RESULTS

In contrast to unchanged circulating leptin in females, male patients exhibited decreased plasma leptin levels compared with male CU counterparts. Moreover, plasma leptin showed no correlation with cognitive performance and AD blood biomarkers in patients with either sex. Of note, females but not males demonstrated an association of plasma leptin with body mass index, high density lipoprotein-cholesterol and its ratio with total cholesterol and triglycerides.

CONCLUSION

Our findings suggest that leptin deficiency is associated with nonobese male AD patients, supporting systemic dysmetabolism in the development of this neurodegenerative disorder in certain populations. Although plasma leptin may have limited capacity to reflect disease severity or progression, future mechanistic studies on the regulation of leptin in nonobese patients with AD would deepen our understanding of the sex-related disparity of AD etiopathogenesis.

The associations of leptin and adiponectin with the metabolic syndrome in an Indonesian and a Dutch population

BACKGROUND AND AIMS

At the same BMI, Asian populations develop cardiometabolic complications earlier than Western populations. We hypothesized that a different secretion of the adipocyte-derived hormones leptin and adiponectin plays a role and investigated the associations of the two hormones with the metabolic syndrome (MetS) in an Indonesian and a Dutch population.

METHODS AND RESULTS

We performed cross-sectional analyses of the Netherlands Epidemiology of Obesity Study (n = 6602) and the SUGAR Scientific Programme Indonesia-Netherlands Study (n = 1461). We examined sex-stratified associations of leptin and adiponectin with MetS, using multivariate logistic regression including adjustment for total body fat. The mean (SD) leptin (mcg/L) were 4.7 (6.0) in Indonesian men, 18.6 (12.0) in Indonesian women, 9.1 (7.7) in Dutch men, and 23.4 (17.4) in Dutch women. The mean (SD) adiponectin (mg/L) were 5.7 (5.4), 7.5 (7.1), 6.6 (3.3), and 11.3 (4.9), respectively. Within the same BMI category, leptin concentrations were similar in the two populations, whereas adiponectin was lower in the Indonesian population. Per SD of leptin, adjusted prevalence odds ratios (ORs, 95%CI) of MetS were 0.9 (0.6-1.2) in Indonesian men, 1.1 (0.9-1.4) in Indonesian women, 2.2 (1.6-2.8) in Dutch men, and 1.2 (1.0-1.5) in Dutch women. Per SD of adiponectin, the ORs were 0.9 (0.7-1.2), 0.8 (0.7-1.0), 0.6 (0.6-0.8), and 0.4 (0.4-0.5), respectively.

CONCLUSIONS

Despite lower adiponectin levels, adiponectin was not related to the MetS in the Indonesian population and can not explain their increased cardiometabolic risk at the same BMI.

D4F prophylaxis enables redox and energy homeostasis while preventing inflammation during hypoxia exposure

Apo-A1 is correlated with conditions like hyperlipidemia, cardiovascular diseases, high altitude pulmonary edema and etc. where hypoxia constitutes an important facet.Hypoxia causes oxidative stress, vaso-destructive and inflammatory outcomes.Apo-A1 is reported to have vasoprotective, anti-oxidative, anti-apoptotic, and anti-inflammatory effects. However, effects of Apo-A1 augmentation during hypoxia exposure are unknown.In this study, we investigated the effects of exogenously supplementing Apo-A1-mimetic peptide on SD rats during hypoxia exposure. For easing the processes of delivery, absorption and bio-availability, Apo-A1 mimetic peptide D4F was used. The rats were given 10 mg/kg BW dose (i.p.) of D4F for 7 days and then exposed to hypoxia. D4F was observed to attenuate both oxidative stress and inflammation during hypoxic exposure. D4F improved energy homeostasis during hypoxic exposure. D4F did not affect HIF-1a levels during hypoxia but increased MnSOD levels while decreasing CRP and Apo-B levels. D4F showed promise as a prophylactic against hypoxia exposure.

Association of Serum Omentin-1, Chemerin, and Leptin with Acute Myocardial Infarction and its Risk Factors

Objective:

To determine the association of serum omentin-1, chemerin, and leptin with acute myocardial infarction (AMI) and its risk factors among individuals admitted with AMI to the coronary care unit (CCU).

Methods:

The current case-control study was conducted at the CCU of King Abdulaziz University Hospital (KAUH), Jeddah, Kingdom of Saudi Arabia (KSA), in 2016-2018. A total of 122 AMI patients admitted to CCU, and 52 BMI and age-matched healthy subjects, between 30 and 65 years of age, were included.

Results:

Chemerin and omentin-1 are independent predictors of the incidence of MI. Furthermore, serum omentin-1 was significantly lowered while chemerin and hsCRP levels were found to be significantly raised among the individuals with AMI compared to the healthy subjects, and no notable change was found in the serum leptin level. Serum omentin-1, chemerin, and leptin were significantly correlated with weight, BMI, waist circumference in patients, and control subjects. Binary logistic regression analysis displayed that the occurrence of MI is positively correlated with fasting plasma glucose (FPG), TC, TG, LDL-C, hsCRP, and chemerin and in a negative manner with HDL-C, and omentin. The chemerin and omentin-1 were also linked with the MI in multiple logistic regression analysis.

Conclusions:

The present results indicated that the serum omentin levels were significantly lowered while chemerin and hsCRP levels were found to be markedly raised among patients. No change was found in serum leptin levels. Serum chemerin and omentin-1 levels were independently associated with the MI. It appears that these parameters may be used to assess the risk spectrum of CAD.

The effect of educational and encouragement interventions on anthropometric characteristics, obestatin and adiponectin levels

BACKGROUND

Lifestyle modification is the most important strategy for control of obesity and overweight. Obestatin and adiponectin are the biomarkers of obesity. Thus, this study was performed to examine the effect of educational and encouragement interventions and lifestyle modifications on obesity anthropometric as well as obestatin and adiponectin levels.

METHODS

This semi-experimental study was conducted on a subsample of TABASSOM study. Participants were 41 overweight and obese children and adolescents aged 6-18 years old and 45 overweight and obese adults aged 19-65 years old. Anthropometric characteristics including height, weight, waist and hip circumferences, and body fat percentage (BFP) were measured at the first and after one year at the end of study. We implemented some educational and encouragement interventions regarding dietary modification and physical activity during the study. Obestatin and adiponectin levels were measured at the first and end of study by enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

The study did not show significant effect on anthropometric characteristics such as body mass index (BMI) and waist circumference (WC). BFP decreased significantly in boys, total children and adolescent group, and waist-to-hip ratio (WHR) decreased significantly only in adolescent boys after 1 year (P < 0.050).

CONCLUSION

Educational and encouraging interventions and lifestyle modifications could lead to decrease of body WHR and BFP in adolescent boys. This is helpful in controlling the increasing rate of obesity.

Metabolic, inflammatory, and oxidative stress markers in women exposed to secondhand smoke

Background

Secondhand smoke (SHS) exposure has adverse effects on the cardiovascular system. This study aimed to determine the effects of SHS on the cardiovascular disease biomarkers, namely the metabolic, inflammatory, and oxidative stress markers in healthy adult women.

Methods

This comparative cross-sectional study was conducted among healthy women. The cases included those women exposed to SHS, and the controls included those women not exposed to SHS. SHS exposure was defined as being exposed to SHS for at least 15 min for 2 days per week. Venous blood was taken to measure the metabolic markers (high molecular weight adiponectin, insulin level, insulin resistance, and nonesterified fatty acids), oxidative stress markers (oxidized low density lipoprotein cholesterol and 8-isoprostane), and inflammatory markers (high-sensitivity C-reactive protein and interleukin-6). A hair nicotine analysis was also performed. An analysis of covariance and a simple linear regression analysis were conducted.

Results

There were 101 women in the SHS exposure group and 91 women in the non-SHS exposure group. The mean (with standard deviation) of the hair nicotine levels was significantly higher in the SHS exposure group when compared to the non-SHS exposure group [0.22 (0.62) vs. 0.04 (0.11) ng/mg; P = 0.009]. No significant differences were observed in the high molecular weight adiponectin, insulin and insulin resistance, nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, interleukin-6, and high-sensitivity C-reactive protein between the two groups. The serum high molecular weight adiponectin was negatively associated with the insulin level and insulin resistance in the women exposed to SHS. However, no significant relationships were seen between the high molecular weight adiponectin and nonesterified fatty acids, 8-isoprostane, oxidized low density lipoprotein cholesterol, high-sensitivity C-reactive protein in the SHS group.

Discussion

There were no significant differences in the metabolic, oxidative stress, and inflammatory markers between the SHS exposure and non-SHS exposure healthy women. A low serum level of high molecular weight adiponectin was associated with an increased insulin level and resistance in the women exposed to SHS.

A study of ghrelin and leptin levels and their relationship to metabolic profiles in obese and lean Saudi women with polycystic ovary syndrome (PCOS)

BACKGROUND

Polycystic ovary syndrome (PCOS) is considered as one of the most frequently encountered hormonal pathologies in women during their reproductive years. Leptin and ghrelin, peptide hormones with adipostatic and orexigenic effect, respectively, seem to be involved in the metabolic changes that occur in PCOS. The aim of this study was to determine serum ghrelin and leptin levels in obese and lean Saudi women with PCOS and to investigate their relationship to the metabolic profiles in these women.

METHODS

This study was conducted as a prospective, observational, cross-sectional, case-control study, at the Department of Obstetrics and Gynecology, Al-Noor Hospital, Makkah, Kingdom of Saudi Arabia. The study population included 252 women [130 women with PCOS (diagnosed according to the Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus, 2003) and 122 normo-ovulatory women as matched controls] attending the outpatient Gynecology Clinic. Demographic details were recorded, blood was extracted following overnight fast and serum was used for the determination of serum ghrelin and leptin levels and other hormonal and biochemical parameters including total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, glucose, and insulin. Insulin resistance and sensitivity were calculated as HOMA-IR and HOMA-S.

RESULTS

No significant differences in ghrelin (P = 0.1830) and leptin (P = 0.8329) levels were detected between the PCOS and control groups. However, ghrelin levels were significantly lower; and leptin levels were significantly higher in obese PCOS patients in comparison with lean patients (P = 0.0001 for both). In the PCOS group, there were significant correlations between ghrelin and leptin levels with Body Mass Index (BMI), waist-hip ratio, total cholesterol, triglycerides, HDL, LDL and insulin levels. Multiple regression analysis demonstrated that insulin was the main determinant for ghrelin (R2 = 0.316) and leptin (R2 = 0.352) levels (P = 0.0001 for both).

CONCLUSIONS

Although serum ghrelin and leptin levels were found to be normal in women with PCOS; yet, there is a relationship, possibly linked to obesity, hyperinsulinemia and insulin resistance between these levels and metabolic profile of Saudi PCOS.

Association of sleep duration with apolipoproteins and the apolipoprotein B/A1 ratio: the China health and nutrition survey

Background

Short sleep duration has been related to established cardiovascular risk factors, likely obesity, diabetes, hypertension and dyslipidaemia. However, to the best of our knowledge, the associations between sleep duration and apolipoprotein concentrations and their ratios have not been investigated to date. This study aimed to explore the independent relationship of sleep duration with apolipoprotein (apo) A1, apoB and the apoB/apoA1 ratio in a Chinese adult population.

Methods

Data from 7381 participants, aged 18 to 75 years, from the National Health and Nutrition Survey 2009 were analysed in this cross-sectional study. Participants were divided into 3 categories according to sleep duration: ≤6, 7-8, and ≥9 h. Logistic regression analysis with odds ratios was employed to assess the association between sleep duration and apo profile.

Results

Using 7-8 h of sleep as a reference, short sleep duration was associated with significantly increased odds of elevated apoB (OR =1.75, 95% CI 1.12-2.72), whereas long sleep duration was correlated with a decreased (but not statistically significant) risk for elevated apoB (OR =0.86, 95% CI 0.54-1.38) among females after controlling for covariates. Among males, long sleep duration was only marginally related to decreased odds ratios for elevated apoB/apoA1 ratio after adjustment for covariates (OR =0.78, 95% CI 0.6-0.99).

Conclusions

These results indicate that short sleep duration is strongly associated with an increased risk of elevated apoB levels in women and that long sleep duration is correlated with decreased apoB/apoA1 levels in men. Sleep hygiene management could serve to treat and prevent cardiovascular diseases by altering unfavourable apo profile.

Enteric parasites can disturb leptin and adiponectin levels in children

INTRODUCTION

Infection by intestinal parasites in childhood may be the main cause of many health-related problems in developed countries such as anemia, anorexia, loss of appetite, retarded growth and development. The aim of the present study was to assess the effect of different intestinal parasites on white adipose tissue hormones.

MATERIAL AND METHODS

Eighty-one children infected by different parasites and 35 apparently healthy children were enrolled in this study. All patients and controls were subjected to clinical examination, measurement of body mass index (BMI) and laboratory examination.

RESULTS

For BMI percentiles, there was a significant increase in serum leptin level (p = 0.042) and a significant decrease in serum adiponectin level (p = 0.039) in uninfected children, whereas there were no significant changes in the infected group (p = 0.068 and 0.082 respectively). A significant increase in leptin and decrease in adiponectin levels were observed for E. histolytica, Strongyloides and E. histolytica and Giardia infections compared to the control group (p = 0.047, 0.035 and 0.019 for leptin, and p = 0.025, 0.038 and 0.041 for adiponectin, respectively).

CONCLUSIONS

The infection by some intestinal parasites may deregulate the secretion of leptin and adiponectin and also affect the absorption of some nutrients which can disturb the BMI and cause anorexia.

Adipocytokines and anthropometric measures in type 2 diabetics

AIM

Type 2 diabetes mellitus has assumed pandemic proportions worldwide. Aggressive management of hyperglycemia in diabetics is a primary goal of treatment. We have previously reported favorable effects of oral hypoglycemic agents on adipocytokines. Aim of the present study was to investigate the relationship of adipocytokines with anthropometric measures and biochemical parameters in type 2 diabetics.

METHODS

Clinically diagnosed type 2 diabetics and age, gender matched healthy volunteers were recruited for study. Anthropometric measurements like height, weight, waist-circumference, hip-circumference were recorded and BMI, waist-hip ratio were calculated. Fasting blood samples were collected from participants and sera were analyzed for glucose, glycated haemoglobin, total cholesterol, SGOT, SGPT, insulin, adiponectin and leptin. Correlation of adipocytokines with anthropometric and biochemical parameters was assessed in healthy and diabetic individuals.

RESULTS

BMI and WHR in diabetics were significantly higher than healthy population. BMI did not show significant association with adipocytokines. Diabetic males with WHR≥0.9 showed negative association with adiponectin and positive association with leptin. WC did not show significant association with adipocytokines in males. Irrespective of WC, healthy females exhibited positive association with leptin. Diabetic females with WC≥88cm showed leptin to be positively associated with WC. Such association of adipocytokines with WHR was not detected in females.

CONCLUSIONS

Body fat distribution can be considered as a parameter in assessing adipokine imbalance. Central adiposity is a better measure of adipokine imbalance than BMI. Abdominal obesity in diabetics correlates with altered levels of adipocytokines indicating its importance in diabetic individuals.

Breast-feeding, Leptin:Adiponectin Ratio, and Metabolic Dysfunction in Adolescents with Obesity

OBJECTIVES

Increased adiposity increases leptin and decreases adiponectin concentrations, resulting in an increased leptin:adiponectin ratio (LAR). In adults, components of the metabolic syndrome and other cardiometabolic risk factors, what we classify here as "metabolic dysfunction," are associated with both a high LAR and a history of being breast-fed. The relation among breast-feeding, LAR, and degree of metabolic dysfunction in obese youth is unknown. The purpose of our pilot study was to explore this relation and estimate the effect size of the relations to determine the sample size needed to power future prospective studies.

METHODS

We obtained fasting levels of leptin, adiponectin, lipids, insulin, and glucose from obese youth (aged 8-17 years). Weight, height, waist circumference, blood pressure, and breast-feeding history also were assessed.

RESULTS

Of 96 participants, 78 were breast-fed as infants, 54% of whom were breast-fed for >6 months. Wide variation was observed in LARs among children who were and were not breast-fed (>100% coefficient of variation). Overall, prevalence of metabolic dysfunction in the cohort was 94% and was not proven to be associated with higher LAR.

CONCLUSIONS

In this cohort of obese youth, we found a high prevalence of breast-feeding, metabolic dysfunction, and wide variation in the LARs. Based on the effect size estimated, future studies would need to enroll >1500 patients or identify, stratify, and selectively enroll obese patients without metabolic dysfunction to accurately determine whether breast-feeding in infancy influences LARs or metabolic dysfunction among obese youth.

Leptin as an important link between obesity and cardiovascular risk factors in men with acute myocardial infarction

OBJECTIVE

The levels of leptin, a major regulator of lipid metabolism, may increase in obesity, and contribute to the development of metabolic syndrome. Leptin is produced by adipose tissue and is a peptide hormone, which has strong association with obesity, elevated cardiovascular risk, and morbidity. The present study was designed to evaluate the relationships between leptin levels, obesity, and cardiovascular risk factors in men with acute myocardial infarction.

METHODS AND RESULTS

Twenty-four obese and twenty-three nonobese male patients, who had experienced their first myocardial infarction, were included in the study. Their leptin levels, biochemical parameters, and anthropometric measures were obtained. Mean leptin levels were significantly higher in the obese group compared to the nonobese group (2.53ng/mL versus 1.23ng/mL; p<0.01). Leptin levels correlated positively with anthropometric measurements, triglyceride, fasting glucose, C-reactive protein, and uric acid levels, and negatively with high-density lipoprotein cholesterol levels.

CONCLUSION

Findings indicate high leptin levels to be positively correlated with obesity and diastolic blood pressure in male patients with myocardial infarction.

Maternal Plane of Nutrition During Late-Gestation and Weaning Age Alter Steer Calf Longissimus Muscle Adipogenic MicroRNA and Target Gene Expression

The main objective was to evaluate if different planes of maternal nutrition during late gestation and weaning age alter microRNA (miRNA) and target gene expression in offspring longissimus muscle (LM). Early (EW) and normal weaned (NW) Angus × Simmental calves (n = 30) born to cows that were grazing endophyte-infected tall fescue and red clover pastures with no supplement [low plane of nutrition (LPN)], or supplemented with 2.3 and 9.1 kg of dried distiller's grains with solubles and soy hulls [medium and high plane of nutrition (MPN, HPN), respectively] during the last 105 ± 11 days of gestation were used. Biopsies of LM were harvested at 78 (early weaning), 187 (normal weaning) and 354 days of age. Results indicate a role of pro-adipogenic miRNA in the control of adipogenesis in LM of NW-MPN steers between 78 and 187 days of age through upregulation of (1) miR-103 which inhibits CAV1, a protein that destabilizes INSR and leads to insulin resistance; (2) miR-143 which inhibits DLK1, a protein that inhibits adipocyte differentiation; and (3) miR-21 which impairs TGFBR2-induced inhibition of adipocyte differentiation. Among the studied anti-adipogenic miRNA, cow plane of nutrition resulted in downregulation of miR-34a expression in MPN steers compared with HPN and LPN at 78 days of age. Data for miR-34a provided a potential sign of epigenetic regulation of LM in beef offspring due to the cow plane of nutrition during late gestation.

Insights into the Genetic Susceptibility to Type 2 Diabetes from Genome-Wide Association Studies of Obesity-Related Traits

Obesity and type 2 diabetes (T2D) are common and complex metabolic diseases, which are caused by an interchange between environmental and genetic factors. Recently, a number of large-scale genome-wide association studies (GWAS) have improved our knowledge of the genetic architecture and biological mechanisms of these diseases. Currently, more than ~250 genetic loci have been found for monogenic, syndromic, or common forms of T2D and/or obesity-related traits. In this review, we discuss the implications of these GWAS for obesity and T2D, and investigate the overlap of loci for obesity-related traits and T2D, highlighting potential mechanisms that affect T2D susceptibility.

Fat-free mass and its predictors in Huntington's disease

The causes of weight loss in Huntington's disease (HD) are not entirely clear. The aim was to identify risk factors that are associated with a loss of metabolically active tissues, i.e. fat-free mass. A consecutive cohort of non-diabetic HD participants (manifest HD, n = 43; CAG: mean 43.6.0 ± 3.6; preHD, n = 10; CAG: mean 41.4 ± 1.4) and 36 healthy controls was recruited. Twenty-five HD participants were early-stage HD (UHDRS Total Functional Capacity [TFC] stages I and II), 12 mid-stage HD (TFC stage III), and 6 participants were in late-stage HD (TFC stages IV and V). Food intake, basic metabolic rate and glucose homeostasis were assessed. In addition, fat-free mass was determined using bioelectric impedance analysis, and leptin, insulin and ghrelin as key metabolic regulators. Sex ratio and age were similar in HD participants (71 % women; age 50.6 ± 10.9) and controls (66 % women; age 46.4 ± 14.5). Body mass index (BMI) was lower in HD participants than controls (median 24.1 vs. 25.9, p = 0.04). However, fat-free mass and basic metabolic rate were not statistically different between groups and showed no association with disease burden. In controls and HD participants, leptin was the most important predictor of fat-free mass. While BMI was lower in HD participants, fat-free mass was similar to controls with leptin as its most important predictor. Leptin levels and fat-free mass measurements using bioelectric impedance analysis may be good screening tools to identify HD patients at risk for weight loss.

High adiponectin levels in lean Arab women compared to Asian women

Adiponectin has been recognized as a potent regulator of metabolism possessing anti-inflammatory and anti-atherogenic functions and inversely associated with increasing incidents of type 2 diabetes and obesity. In this study, we investigated the changes in adiponectin level of 193 Arab and 132 Asian women were compared. Overall, Arab women had statistically significant higher levels of adiponectin 17.84 (1.047) μg/mL than Asians 12.87 (1.049) μg/mL. In conclusion, our data demonstrates that Arab women poses high adiponectin level compared to Asians and the protective role of adiponectin in Arab women against metabolic disorders requires further attention.

Adipokines and biochemical changes in Egyptian obese subjects: possible variation with sex and degree of obesity

The purpose of this study was firstly to evaluate the adipokines and biochemical changes in obese subjects in relation to different grades of obesity and in relation to gender difference (males versus females) and secondly to evaluate the role of TNF-α in obesity. From January 2013 to February 2014, a total number of 120 non-diabetic subjects of both sexes were recruited and randomly selected from Dr. Abd-Elhamid Elsheikh center for physiotherapy and weight control, El-menofia-Egypt. Those subjects were classified according to their sex into two main groups; the female group and the male group. The female group (60 women) was distributed according to BMI into group 1 (15 lean women), group 2 (15 class I obese women), group 3 (15 class II obese women), and group 4 (15 class III obese women). The male group (60 men) was also distributed according to the BMI into group 1 (15 lean men), group 2 (15 class I obese men), group 3 (15 class II obese men), and group 4 (15 class III obese men). All individuals enrolled in the study were submitted to weight and height measurements with subsequent calculation of body mass index. Fasting blood samples were collected from all participants for quantitative determination of blood glucose, serum lipid, TNF-α, leptin, and adiponectin levels. One-way analysis of variance followed by LSD post hoc test was used for comparison of variables. In obese subjects of both sexes, it was found that circulating leptin and TNF-α levels were significantly high (P<0.05) and positively correlated to BMI. In contrast to leptin, adiponectin concentrations were significantly low (P<0.05) and inversely correlated to BMI. Regarding gender difference, although serum leptin and adiponectin levels were higher in women than men, men showed higher atherogenic parameters. We conclude that leptin, TNF-α, and adiponectin were related to both BMI and grades of obesity. Furthermore, TNF-α may play a role in obesity.

Incretin response in Asian type 2 diabetes: Are Indians different?

Incretin-based therapy has clearly emerged as one of the most sought out strategy in managing type 2 diabetes, primarily because they generally do not causes hypoglycemia and possess weight-neutral or weight losing properties. Efficacy-wise too, these agents, are more or less similar to commonly used drugs metformin and sulfonylureas. Interestingly, some studies recently suggested that glycemic response to these incretin-based therapies could also differ ethnicity-wise. Subsequently, meta-analysis from these studies also suggested that Asians may have better response to these incretin-based therapies. This review will be an attempt to critically analyze those studies available in literature and to address as to why East-Asians and South-Asians may have different incretin response compared to non-Asians.

Chronic variable stress improves glucose tolerance in rats with sucrose-induced prediabetes

The incidence of type-2 diabetes (T2D) and the burden it places on individuals, as well as society as a whole, compels research into the causes, factors and progression of this disease. Epidemiological studies suggest that chronic stress exposure may contribute to the development and progression of T2D in human patients. To address the interaction between chronic stress and the progression of T2D, we developed a dietary model of the prediabetic state in rats utilizing unlimited access to 30% sucrose solution (in addition to unlimited access to normal chow and water), which led to impaired glucose tolerance despite elevated insulin levels. We then investigated the effects of a chronic variable stress paradigm (CVS; twice daily exposure to an unpredictable stressor for 2 weeks) on metabolic outcomes in this prediabetic model. Chronic stress improved glucose tolerance in prediabetic rats following a glucose challenge. Importantly, pair-fed control groups revealed that the beneficial effect of chronic stress did not result from the decreased food intake or body weight gain that occurred during chronic stress. The present work suggests that chronic stress in rodents can ameliorate the progression of diet-induced prediabetic disease independent of chronic stress-induced decreases in food intake and body weight.

Cardiovascular risk among South Asians living in Canada: a systematic review and meta-analysis

BACKGROUND

South Asians represent about 3% of the Canadian population and have a higher burden of certain cardiovascular risk factors and cardiovascular disease (CVD) compared with white people. The objective of this study was to review the literature to compare cardiovascular risk factors and disease management practices among adult South Asian and white Canadians.

METHODS

We searched MEDLINE, Embase, Cochrane and Cumulative Index to Nursing and Allied Health Literature databases from their inception through Feb. 17, 2014 and the reference lists of the selected articles. English-language studies of interventions and observational studies of biological mechanisms underlying CVD risk in South Asians conducted in Canada were eligible for inclusion. Where appropriate, we used random-effects meta-analyses to integrate results comparing the CVD risk profiles of South Asian and white Canadians.

RESULTS

We included 50 articles (n = 5 805 313 individuals) in this review. Compared with white Canadians, South Asian Canadians had a higher prevalence and incidence of CVD, an increased prevalence of diabetes (odds ratio [OR] 2.25, 95% confidence interval [CI] 1.81 to 2.80, p < 0.001) and hypertension (OR 1.11, 95% CI 1.02 to 1.22, p = 0.02), lower high-density lipoprotein cholesterol levels (mean difference -0.19 mmol/L, 95% CI -0.25 to -0.13 mmol/L, p < 0.001) and a higher percentage of body fat (men: absolute mean difference 3.23%, 95% CI 0.83% to 5.62%, p = 0.008; women: absolute mean difference 4.09%, 95% CI 3.46% to 4.72%, p < 0.001). South Asian people are also more sedentary, consume higher levels of carbohydrates and are less likely to smoke tobacco (OR 0.38, 95% CI 0.24 to 0.60, p < 0.001]) than white Canadians. No differences in access to diagnostic tests, outcomes following cardiovascular surgery or use of cardiac rehabilitation programs were apparent.

INTERPRETATION

Compared with white people, South Asian people living in Canada have a higher prevalence and incidence of CVD and possess a unique cardiovascular risk profile.

The relationship between regional abdominal fat distribution and both insulin resistance and subclinical chronic inflammation in non-diabetic adults

OBJECTIVE

Obesity is associated with a high risk of insulin resistance (IR) and its metabolic complications. It is still debated that distributions of adipose tissue relate to an excess risk of IR and chronic inflammation in different race. This study was designed to examine the relation between insulin sensitivity, chronic inflammation and central fat distribution in non-diabetic volunteers in Taiwanese.

METHODS

There were 328 volunteers without family history of diabetes mellitus and with normal oral glucose tolerance test enrolled. Total body fat and abdominal fat were measured. Abdominal fat was categorized into intraperitoneal (IP), retroperitoneal (RP) and subcutaneous (SC) fat. The IR index was estimated by homeostatic model assessment. Five inflammatory markers: adiponectin, leptin, tumor necrosing factor-α (TNF-α), resistin and high sensitive CRP (hs-CRP) were measured.

RESULTS

IR was related to IP fat (r = 0.23, p < 0.001), but not RP fat, SC fat or total body fat. After correcting for age and sex, IP fat was the only significant predictor of IR (r2 = 58%, p = 0.001). Leptin showed the strongest relationship with all fat compartments (IP fat: r = 0.44, p = 0.001; RP fat: r = 0.36, p = 0.005, SC fat: r = 0.54, p < 0.001; total body fat: r = 0.61, p < 0.001). The hs-CRP and adiponectin were closely related both to IP (r = 0.29, p = 0.004; r = -0.20, p = 0.046, respectively) and total body fat (r = 0.29, p = 0.004; r = -0.29, p = 0.005, respectively), but not RP, or SC fat. TNF-α and resistin were not correlated to any fat compartment. After correcting for age and sex, leptin variance was mostly explained by SC fat (41.3%), followed by IP fat (33.6%) and RP fat (25.3%). The hs-CRP and adiponectin variance were mostly explained by IP fat (40% and 49% respectively).

CONCLUSIONS

IP fat is better predictors of IR and subclinical chronic inflammation in Taiwanese adults. A disproportionate accumulation of abdominal fat is associated with increased risk of cardiovascular diseases.

Obesity and dyslipidemia in South Asians. Nutrients. 2013;5:2708-2733. [PMID: 23863826 PMCID: PMC3738996 DOI: 10.3390/nu5072708]

Obesity and dyslipidemia are emerging as major public health challenges in South Asian countries. The prevalence of obesity is more in urban areas than rural, and women are more affected than men. Further, obesity in childhood and adolescents is rising rapidly. Obesity in South Asians has characteristic features: high prevalence of abdominal obesity, with more intra-abdominal and truncal subcutaneous adiposity than white Caucasians. In addition, there is greater accumulation of fat at “ectopic” sites, namely the liver and skeletal muscles. All these features lead to higher magnitude of insulin resistance, and its concomitant metabolic disorders (the metabolic syndrome) including atherogenic dyslipidemia. Because of the occurrence of type 2 diabetes, dyslipidemia and other cardiovascular morbidities at a lower range of body mass index (BMI) and waist circumference (WC), it is proposed that cut-offs for both measures of obesity should be lower (BMI 23–24.9 kg/m² for overweight and ≥25 kg/m² for obesity, WC ≥80 cm for women and ≥90 cm for men for abdominal obesity) for South Asians, and a consensus guideline for these revised measures has been developed for Asian Indians. Increasing obesity and dyslipidemia in South Asians is primarily driven by nutrition, lifestyle and demographic transitions, increasingly faulty diets and physical inactivity, in the background of genetic predisposition. Dietary guidelines for prevention of obesity and diabetes, and physical activity guidelines for Asian Indians are now available. Intervention programs with emphasis on improving knowledge, attitude and practices regarding healthy nutrition, physical activity and stress management need to be implemented. Evidence for successful intervention program for prevention of childhood obesity and for prevention of diabetes is available for Asian Indians, and could be applied to all South Asian countries with similar cultural and lifestyle profiles. Finally, more research on pathophysiology, guidelines for cut-offs, and culturally-specific lifestyle management of obesity, dyslipidemia and the metabolic syndrome are needed for South Asians.

Portal vein and systemic adiponectin concentrations are closely linked with hepatic glucose and lipoprotein kinetics in extremely obese subjects

Low systemic plasma adiponectin concentrations are associated with abnormalities in hepatic glucose and lipoprotein metabolism in obese people. However, the relationship between the delivery of adiponectin to the liver via the portal vein and hepatic glucose and lipoprotein metabolism is not known. We examined the relationship between hepatic substrate metabolism (glucose rate of appearance into plasma and hepatic very low-density lipoprotein [VLDL]-triglyceride [TG] and VLDL-apolipoprotein B-100 [apoB-100] secretion rates, determined by using stable isotope-labeled tracer techniques) and portal vein adiponectin concentration, in 8 insulin-resistant, extremely obese subjects (body mass index, 65 ± 7 kg/m(2)). Portal vein adiponectin concentration was inversely associated with basal glucose rate of appearance (r = -0.820, P = .013) and VLDL-TG (r = -0.823, P = .012) and VLDL-apoB-100 (r = -0.787, P = .020) secretion rates. Very similar correlations were obtained for radial artery adiponectin as a result of a mirroring relationship between portal and arterial adiponectin concentrations (r = 0.899, P = .002) and the absence of significant arteriovenous concentration differences (P = .570). Insulin resistance, assessed with the homeostasis model assessment score, was also strongly associated with hepatic glucose and lipid metabolic parameters, as well as with adiponectin concentrations in the portal vein and radial artery. These results suggest that adiponectin delivery to the liver, whether via the portal or the systemic circulation, may be an important regulator of basal hepatic glucose, VLDL-TG, and VLDL-apoB-100 production rates in obese people, possibly through direct effects on the liver or changes in hepatic insulin sensitivity. However, portal vein adiponectin does not appear to be superior to arterial adiponectin as a marker of hepatic metabolic dysregulation. Additional studies are needed to elucidate the mechanism(s) responsible for the strong association we observed between adiponectin and hepatic substrate metabolism.

Adiponectin expression in subcutaneous adipose tissue is reduced in women with cellulite

BACKGROUND

Cellulite, which appears as orange peel-type or cottage cheese-like dimpling of the skin on the thighs and buttocks, is a complex, multifactorial, cosmetic disorder of the subcutaneous fat layer and the overlying superficial skin. Adiponectin is an adipocyte-derived hormone mainly produced by subcutaneous fat that shows important protective anti-inflammatory and vasodilatory effects. We hypothesized that adiponectin expressed in the subcutaneous adipose tissue (SAT) might play a role in the pathogenesis of cellulite. We reasoned that a reduction in the expression of adiponectin - a humoral vasodilator - in the SAT of cellulite areas might contribute to the altered microcirculation frequently found in these regions.

METHODS

A total of 15 lean (body mass index [BMI] < 25 kg/m(2) ) women with cellulite and 15 age- and BMI-matched women without cellulite participated in this study. Real-time reverse transcription polymerase chain reaction (RT-PCR) was used to assess adiponectin gene expression. Plasma adiponectin levels were measured using a commercial enzyme immunoassay kit.

RESULTS

Adiponectin mRNA expression in the SAT of the gluteal region was significantly lower in areas with cellulite compared with those without (12.6 ± 3.1 AU versus 16.6 ± 4.1 AU; P=0.006). However, plasma adiponectin levels did not differ between women with (20.3 ± 7.3 μg/ml) and without (19.3 ± 6.1 μg/ml) cellulite (P=0.69).

CONCLUSIONS

Adiponectin expression is significantly reduced in the SAT in areas affected by cellulite. Our findings provide novel insights into the nature of cellulite and may give clues to the treatment of this cosmetic issue.

High-intensity endurance training improves adiponectin mRNA and plasma concentrations

Adiponectin is an anti-inflammatory protein that reduced in obesity. Exercise training may reduce the adipose tissue (AT), although it is not well known whether exercise-induced change in AT, increases the adiponectin mRNA expression and plasma concentrations or not; therefore, the purpose of this study was to investigate the adiponectin mRNA and plasma concentrations in middle-aged men after 12 weeks high-intensity exercise training and after a week detraining. Sixteen sedentary overweight and obese middle-aged men (age 41.18 ± 6.1 years; ± SD) volunteered to participate in this study. The subjects were randomly assigned to training group (n = 8) or control group (n = 8). The training group performed endurance training 4 days a week for 12 weeks at an intensity corresponding to 75-80% individual maximum oxygen consumption for 45 min. After 12 weeks of training, subjects underwent a week of detraining. The results showed that the BMI as well as central and peripheral AT volume were decreased in the training group compared to the control group (P < 0.05). After 12 weeks, the training group resulted in a significant increase (P < 0.05) in the adiponectin gene expression in abdominal and gluteal subcutaneous AT when compared with the control group. The results showed that plasma adiponectin concentrations increased and insulin resistance decreased after training compared to the control group (P < 0.05). After a week of detraining, the variables were not changed significantly in the training group. In conclusion, high-intensity endurance training caused an increase adiponectin mRNA in obese middle-aged men.

Ethnicity modifies the relationships of insulin resistance, inflammation, and adiponectin with obesity in a multiethnic Asian population

OBJECTIVE

The development of obesity-related metabolic disorders varies with ethnicity. We examined whether ethnicity modifies the relationship between BMI and three metabolic pathways (insulin resistance, inflammation, and adiponectin) that are involved in the pathogenesis of diabetes and cardiovascular disease (CVD).

RESEARCH DESIGN AND METHODS

We analyzed data from 4,804 Chinese, Malay, and Asian-Indian residents of Singapore with complete data on insulin resistance (IR), C-reactive protein (CRP), and total adiponectin levels. Linear regression models with an interaction term ethnicity*BMI were used to evaluate whether ethnicity modifies the association between BMI and IR, CRP, and adiponectin.

RESULTS

In both uni- and multivariate analyses, BMI was directly associated with IR and CRP and inversely with adiponectin across all ethnic groups. When compared with Chinese and Malays, Asian-Indians had higher IR and CRP and lower adiponectin levels. The associations between BMI and its metabolic pathways were significantly stronger in Chinese than in other ethnic groups. The increase in IR and CRP and the decrease in adiponectin for each unit increase in BMI were greater in Chinese than in other ethnic groups. The findings were similar when waist circumference was used in the analyses instead of BMI.

CONCLUSIONS

The impact of BMI on IR, CRP, and adiponectin appears greater in Chinese as compared with other major Asian ethnic groups. This may partly explain the rapid increase in the prevalence of diabetes and CVD in Chinese populations and highlights the importance of weight management in Asian ethnic groups despite the apparently low levels of obesity.

Obesity-related non-communicable diseases: South Asians vs White Caucasians

South Asians are at higher risk than White Caucasians for the development of obesity and obesity-related non-communicable diseases (OR-NCDs), including insulin resistance, the metabolic syndrome, type 2 diabetes mellitus (T2DM) and coronary heart disease (CHD). Rapid nutrition and lifestyle transitions have contributed to acceleration of OR-NCDs in South Asians. Differences in determinants and associated factors for OR-NCDs between South Asians and White Caucasians include body phenotype (high body fat, high truncal, subcutaneous and intra-abdominal fat, and low muscle mass), biochemical parameters (hyperinsulinemia, hyperglycemia, dyslipidemia, hyperleptinemia, low levels of adiponectin and high levels of C-reactive protein), procoagulant state and endothelial dysfunction. Higher prevalence, earlier onset and increased complications of T2DM and CHD are often seen at lower levels of body mass index (BMI) and waist circumference (WC) in South Asians than White Caucasians. In view of these data, lower cut-offs for obesity and abdominal obesity have been advocated for Asian Indians (BMI; overweight >23 to 24.9 kg m(-2) and obesity ≥ 25 kg m(-2); and WC; men ≥ 90 cm and women ≥ 80 cm, respectively). Imbalanced nutrition, physical inactivity, perinatal adverse events and genetic differences are also important contributory factors. Other differences between South Asians and White Caucasians include lower disease awareness and health-seeking behavior, delayed diagnosis due to atypical presentation and language barriers, and religious and sociocultural factors. All these factors result in poorer prevention, less aggressive therapy, poorer response to medical and surgical interventions, and higher morbidity and mortality in the former. Finally, differences in response to pharmacological agents may exist between South Asians and White Caucasians, although these have been inadequately studied. In view of these data, prevention and management strategies should be more aggressive for South Asians for more positive health outcomes. Finally, lower cut-offs of obesity and abdominal obesity for South Asians are expected to help physicians in better and more effective prevention of OR-NCDs.

APOA1/A5 variants and haplotypes as a risk factor for obesity and better lipid profiles in a Brazilian Elderly Cohort

Genetic variations in the APOA1/C3/A4/A5 gene cluster have been studied and proposed to be the leading key for susceptibility to cardiovascular diseases and age-associated disorders. We aimed to investigate the associations of rs12721026 (APOA1) and rs1729408 (APOA5) polymorphisms and their haplotypes with some age-related diseases, as well as with lipids and proteins serum levels in a cohort from a Brazilian Elderly Longitudinal Study (EPIDOSO). Genotyping was performed by polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). Statistical analyses were carried out using logistic regression analysis, Student's t-test, and linkage disequilibrium (LD) analysis. Polymorphic allele frequencies were 0.095 and 0.449 for rs12721026 and rs1729408, respectively. The C-allele of rs1729408 was associated with higher high-density lipoprotein (HDL) (P = 0.022) and glycated hemoglobin levels (P = 0.020). We also showed that rs12721026 and rs1729408 were in LD. The GC haplotype, which is composed of the G-allele of rs12721026 and the C-allele of rs1729408, was significantly associated with obesity (P = 0.028), with higher glycated hemoglobin (P = 0.006), and fasting glucose (P = 0.0003) compared to the TT haplotype, which includes the wild-type alleles of both polymorphisms. Moreover, we found an association between the TC haplotype and higher HDL levels (P = 0.0039). This is the first time that haplotypes involving these polymorphisms were evaluated. Our results showed that these polymorphisms were involved in the development of obesity and in alterations of lipids and proteins serum levels in a Brazilian population. The present findings might also clarify the role of these polymorphisms and their haplotypes in lipids and proteins metabolism.

Adiponectin is independently associated with apolipoprotein B to A-1 ratio in Koreans

Apolipoprotein B to A-1 (apo B/A-1) ratio is reportedly a better predictor of atherosclerotic vascular disease than low-density lipoprotein cholesterol (LDL-C). The aim of this study was to assess the association of serum apo B/A-1 ratio with insulin resistance and adiponectin in patients with different grades of glucose intolerance. Patients were divided according to glucose tolerance into 3 groups: normal glucose tolerance without metabolic syndrome (n = 229), impaired fasting glucose (subjects with fasting plasma glucose level between 100 and 125 mg/dL, n = 658), and type 2 diabetes mellitus (n = 381). Serum concentrations of apo B, apo A-1, glucose, total cholesterol (TC), triglycerides, and high-density lipoprotein cholesterol (HDL-C) and adiponectin were measured. Insulin resistance was estimated by the homeostasis model assessment of insulin resistance index (HOMA-IR). There were significant differences in metabolic parameters among the groups, including waist circumference, insulin, HOMA-IR, and apo B/A-1 ratio, which increased sequentially with glucose intolerance, whereas adiponectin level decreased with increasing severity of glucose intolerance. The apo B/A-1 ratio was significantly correlated with TC, triglycerides, LDL-C, HDL-C, adiponectin, and HOMA-IR in normal glucose tolerance, impaired fasting glucose, and type 2 diabetes mellitus. Multiple regression analysis showed that apo B/A-1 ratio was significantly associated with TC, LDL-C, HDL-C, and adiponectin. In conclusion, apo B/A-1 ratio was significantly associated with insulin resistance according to glucose intolerance; and serum adiponectin was an important independent factor associated with apo B/A-1 ratio in Koreans.

Serum RANKL, osteoprotegerin (OPG), and RANKL/OPG ratio in nephrotic children

Receptor activator of NF-kB ligand (RANKL) and osteoprotegerin (OPG) play key roles in the pathogenesis of glucocorticoid-induced osteoporosis (GIO). The aim of our study was to determine whether the cumulative glucocorticoid dose (CGCS) in children with idiopathic nephrotic syndrome (INS) has any effect on the concentration of serum RANKL and OPG and the RANKL/OPG ratio. The study population consisted of 90 children with INS, aged 3-20 years, who were treated with GCS. These children were divided into two groups according to the CGCS: low (L)<1 g/kg body weight (BW) and high (H)>or=1 g/kg BW, respectively. The control group (C) consisted of 70 healthy children. RANKL concentration was observed to be significantly higher and OPG significantly lower in INS children than in the reference group: 0.21 (range 0.01-1.36) versus 0.15 (0-1.42) pmol/l (p<0.05), respectively, and 3.76 (1.01-7.25) versus 3.92 (2.39-10.23) pmol/l (p<0.05), respectively. The RANKL/OPG ratio was significantly higher in INS children (p<0.01). The concentration of RANKL, similar to the RANKL/OPG ratio, was significantly higher in Group H children than in Group L children: 0.46 (0.02-1.36 ) versus 0.19 (0.01-1.25) (p<0.01) and 0.14 (0.01-0.71) versus 0.05 (0.002-0.37) (p<0.01), respectively. The concentration of OPG was similar in both groups. There was a positive correlation between CGCS and the concentration of sRANKL as well as the RANKL/OPG ratio (in both cases r=0.33, p<0.05). Based on these results, we suggest that long-term exposure to GCS results in a dose-dependent increase in serum RANKL concentration and the RANKL/OPG ratio, but not in the level of serum OPG.

Racial difference in Acylation Stimulating Protein (ASP) correlates to triglyceride in non-obese and obese African American and Caucasian women

Background

Acylation Stimulating Protein (ASP) has been shown to influence adipose tissue triglyceride (TG) storage. The aim was to examine ethnic differences in ASP and leptin levels in relation to lipid profiles and postprandial changes amongst African American (AA) and Caucasian American (CA) women matched for BMI.

Methods

129 women were recruited in total (age 21 – 73 y): 24 non-obese (BMI < 30 kg/m²) CA, 27 obese (BMI ≥ 30 kg/m²) CA, 13 obese diabetic CA, 25 non-obese AA, 25 obese AA, and 15 obese diabetic AA. Cholesterol, HDL-C, LDL-C, apoB, glucose and insulin were measured at baseline. TG, non-esterified fatty acids, leptin, and ASP were measured at baseline and postprandially following a fat meal.

Results

ASP, leptin, insulin and TG were significantly increased in obese subjects within each race. However, AA women had significantly lower ASP and TG than CA women at all BMI. Obese and diabetic AA women had significantly lower apoB levels than CA women when compared to their respective counterparts. For AA women, fasting ASP was positively correlated with BMI, cholesterol, apoB, LDL-C and glucose. For CA women, fasting ASP was positively correlated with BMI, leptin, glucose and insulin. However, for any given BMI, ASP was significantly reduced in AA vs CA (p = 0.0004). Similarly, for any given leptin level or TG levels, ASP was significantly lower in AA women (p = 0.041 and p = 0.003, respectively).

Conclusion

CA women have higher baseline TG levels and an earlier TG peak that is accompanied with higher ASP levels suggesting increased ASP resistance, while AA women have lower baseline TG levels and a later TG peak at lower ASP levels suggesting increased ASP sensitivity. This may explain why AA women may have fewer metabolic complications, such as diabetes and CVD, when compared to their Caucasian counterparts at the same level of obesity.

Obesity and diabetes: lipids, ‘nowhere to run to’. Clin Sci (Lond). 2009;116:113-123. [PMID: 19076064 DOI: 10.1042/cs20080050]

Although specific pathogenic entities contributing to diabetic risk, such as central adiposity, ectopic fat accumulation, hyperlipidaemia and inflammation, are well-characterized, the response of cellular systems to such insults are less well understood. This short review highlights the effect of increasing fat mass on ectopic fat accumulation, the role of triacylglycerols (triglycerides) in Type 2 diabetes mellitus and cardiovascular disease pathogenesis, and selected current therapeutic strategies used to ameliorate these risk factors.

Leptin and coronary heart disease: prospective study and systematic review

OBJECTIVES

This study sought to better determine the link between leptin and coronary heart disease (CHD).

BACKGROUND

Circulating leptin is considered a risk factor for CHD but larger studies are needed.

METHODS

Leptin levels were measured in 550 men with fatal CHD or nonfatal myocardial infarction and in 1,184 controls nested within a prospective study of 5,661 British men and set in context with a meta-analysis.

RESULTS

Baseline leptin correlated with body mass index (BMI), blood pressure, total cholesterol, triglyceride, and inflammatory markers; correlations persisted after BMI adjustment. The within-person consistency of leptin values over 4 years (correlation coefficient: 0.79; 95% confidence interval [CI]: 0.73 to 0.83) was higher than those of some established cardiovascular risk factors. In a comparison of individuals in the top third with those in the bottom third of baseline leptin, the age- and town-adjusted odds ratio for CHD was 1.25 (95% CI: 0.96 to 1.62), decreasing to 0.98 (95% CI: 0.72 to 1.34) after adjustment for BMI. A systematic review identified 7 prospective reports with heterogeneous findings (I(2) = 60%, 13% to 82%). The combined adjusted risk ratio across all studies was 1.44 (95% CI: 0.95 to 2.16) in a comparison of extreme thirds of leptin levels. The inconsistency between studies was partially explained by sample size, with combined estimates from studies involving >100 CHD cases (1.28, 95% CI: 0.80 to 2.04) being somewhat weaker than those from smaller studies (1.81, 95% CI: 0.76 to 4.31).

CONCLUSIONS

Previous studies appear to have overestimated associations of leptin and CHD risk. Our results suggest a moderate association that is largely dependent on BMI.

Relatively high levels of serum adiponectin in obese women, a potential indicator of anti-inflammatory dysfunction: relation to sex hormone-binding globulin

It is unclear whether serum adiponectin concentrations diminish linearly with increasing adiposity and, if not, which factors codetermine this association. These issues were investigated cross-sectionally in 1188 men and women, representative of middle-aged and elderly Turkish adults. Serum total adiponectin was assayed by ELISA. Serum adiponectin values in men, though declining significantly in transition from the bottom to the mid tertile of body mass index (BMI) and waist circumference (WC), were similar in the two respective upper tertiles. In women, serum adiponectin concentrations were not significantly different in any tertile of these indices, were significantly correlated with BMI or WC within the low tertiles and not within the two higher tertiles. In a linear regression analysis for WC (or BMI) in a subset of the sample in which serum sex hormone-binding globulin (SHBG) was available and which additionally comprised adiponectin, fasting insulin and other confounders, only insulin and, in women SHBG, were significantly associated, but not adiponectin. In linear regression analyses for covariates of adiponectin in two models comprising 12 variables, insulin and SHBG concentrations were significantly associated in both genders though not BMI. Whereas in men HDL-cholesterol and CRP were covariates of adiponectin (both p<0.01), SHBG and apolipoprotein B positively associated in women (p<0.001), independent of BMI and fasting insulin levels.

Conclusions: Relationship between excess adiposity and adiponectin levels is inconsistent in Turkish adults. Independently from obesity and hyperinsulinemia, serum adiponectin discloses significant relationship with inflammatory markers and HDL only in men, not in women in whom it is influenced by SHBG, with consequent attenuation of its anti-inflammatory activities.

Leptin G-2548A promoter polymorphism is associated with increased plasma leptin and BMI in Brazilian women

Variants in leptin gene (LEP) have been implicated in the pathogenesis of obesity. The relationship between LEP G-2548A polymorphism and obesity-related traits was evaluated in a sample of Brazilian women (n = 228) who were randomly selected from two clinical centers in Sao Paulo city. Blood samples were collected for DNA extraction, plasma leptin and serum lipids measurements. LEP G-2548A genotypes were identified by a PCR- RFLP strategy using the endonuclease Alw44I. LEP G-2548A was associated with obesity after adjustment for covariates (age, hypertension, coronary artery disease, smoking and physical activity). Women carrying G allele had a four times higher risk of obesity than the A allele carriers (OR: 4.11, CI95%: 1.06-15.90, p = 0.041). G allele was also related to increased plasma leptin (p = 0.024) and body mass index (p = 0.027). Hypertension, hyperglycemia, dyslipidemia and coronary artery disease were associated with obesity. However LEP G-2548A polymorphism was not related to these variables. All together these data suggest that LEP G-2548A polymorphism has an important role in regulating plasma leptin levels and body mass index in women.

Intra-individual variation of plasma adipokine levels and utility of single measurement of these biomarkers in population-based studies

Adipokines, soluble mediators produced by adipocytes, may link adipose tissue to the inflammatory, metabolic, and immune dysregulation that characterize many obesity-related diseases. The stability of plasma adipokine levels within individuals, their seasonal variability, intercorrelations, and relationships to well-established measures of adiposity are incompletely defined. We measured levels of 12 adipokines [interleukin 1beta (IL-1beta), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), plasminogen activator inhibitor-1 (PAI-1), high-sensitivity C-reactive protein (hsCRP), monocyte chemoattractant protein-1 (MCP-1), nerve growth factor (NGF), leptin, adiponectin, hepatocyte growth factor (HGF), and resistin] in four seasonal random plasma samples of 48 male participants of a population-based cohort study. The representativeness of single measurements was assessed by correlating the adipokine levels of a single, random sample with the mean levels from the remaining three samples using a bootstrap approach and using intra-class correlation coefficients (ICC). Spearman correlations between adipokine levels, age, body mass index (BMI), and waist-to-hip ratio (WHR) were estimated. Correlations between plasma adipokine levels from one random sample and the mean of the remaining three seasonal samples ranged from 0.57 to 0.89. Over the 1-year study period, the ICCs for adipokine levels ranged from 0.44 (PAI-1) to 0.83 (HGF). IL-8, MCP-1, and resistin levels were positively associated with age; HGF and PAI-1 levels were correlated with BMI and WHR. This study suggests that adipokine levels in a single blood sample may be useful biomarkers of inflammation in population-based studies of obesity-related disease.

Pathogenic potential of adipose tissue and metabolic consequences of adipocyte hypertrophy and increased visceral adiposity

When caloric intake exceeds caloric expenditure, the positive caloric balance and storage of energy in adipose tissue often causes adipocyte hypertrophy and visceral adipose tissue accumulation. These pathogenic anatomic abnormalities may incite metabolic and immune responses that promote Type 2 diabetes mellitus, hypertension and dyslipidemia. These are the most common metabolic diseases managed by clinicians and are all major cardiovascular disease risk factors. 'Disease' is traditionally characterized as anatomic and physiologic abnormalities of an organ or organ system that contributes to adverse health consequences. Using this definition, pathogenic adipose tissue is no less a disease than diseases of other body organs. This review describes the consequences of pathogenic fat cell hypertrophy and visceral adiposity, emphasizing the mechanistic contributions of genetic and environmental predispositions, adipogenesis, fat storage, free fatty acid metabolism, adipocyte factors and inflammation. Appreciating the full pathogenic potential of adipose tissue requires an integrated perspective, recognizing the importance of 'cross-talk' and interactions between adipose tissue and other body systems. Thus, the adverse metabolic consequences that accompany fat cell hypertrophy and visceral adiposity are best viewed as a pathologic partnership between the pathogenic potential adipose tissue and the inherited or acquired limitations and/or impairments of other body organs. A better understanding of the physiological and pathological interplay of pathogenic adipose tissue with other organs and organ systems may assist in developing better strategies in treating metabolic disease and reducing cardiovascular disease risk.

Adiponectin level and left ventricular hypertrophy in Japanese men

A recent study has demonstrated that adiponectin inhibited hypertrophic signaling in the myocardium of mice, implying that a decrease in the blood adiponectin level could cause cardiac muscle hypertrophy. We hypothesized that a relationship might exist between the serum adiponectin level and electrocardiographically diagnosed left ventricular hypertrophy (ECG-LVH), and we examined this hypothesis by epidemiological study of 2839 Japanese male workers who were not taking medications for hypertension. ECG-LVH was defined as meeting Sokolow-Lyon voltage criteria and/or Cornell voltage-duration product. The subjects were categorized by tertiles of serum adiponectin level, and a multivariate logistic regression analysis was conducted relating left ventricular hypertrophy to adiponectin tertiles adjusting for potential confounding factors. Prevalence of ECG-LVH in the studied sample was 16.7%. Adiponectin ranged from 1.0 to 5.0 microg/mL in the lowest category and from 7.4 to 30.6 microg/mL in the highest. Compared with subjects in the highest adiponectin category, those in the lowest one had a significantly higher prevalence of ECG-LVH independent of age, body mass index, and systolic blood pressure with an odds ratio of 1.50 and a 95% CI of 1.16 to 1.94. Further adjustment for high-density lipoprotein cholesterol, triglyceride, and insulin resistance did not change the association (odds ratio: 1.68; 95% CI: 1.28 to 2.21; P<0.001). Similar results were obtained when different criteria for ECG-LVH were used or when subjects were stratified by blood pressure or body mass index. Adiponectin concentration was inversely and independently associated with ECG-LVH in Japanese men.