Abdominal visceral adiposity influences CD4+ T cell cytokine production in pregnancy

Women with pre-gravid obesity are at risk for pregnancy complications. While the macrophage response of obese pregnant women categorized by body mass index (BMI) has been documented, the relationship between the peripheral CD4⁺ T cell cytokine profile and body fat compartments during pregnancy is unknown. In this study, third trimester peripheral CD4⁺ T cell cytokine profiles were measured in healthy pregnant women [n = 35; pre-pregnancy BMI: 18.5–40]. CD4⁺ T cells were isolated from peripheral blood mononuclear cells and stimulated to examine their capacity to generate cytokines. Between 1 and 3 weeks postpartum, total body fat was determined by dual-energy X-ray absorptiometry and abdominal subcutaneous and visceral fat masses were determined by magnetic resonance imaging. Pearson’s correlation was performed to assess relationships between cytokines and fat mass. Results showed that greater abdominal visceral fat mass was associated with a decrease in stimulated CD4⁺ T cell cytokine expression. IFN-gamma, TNF-alpha, IL-12p70, IL-10 and IL-17A were inversely related to visceral fat mass. Chemokines CCL3 and IL-8 and growth factors G-CSF and FLT-3L were also inversely correlated. Additionally, total body fat mass was inversely correlated with FGF-2 while abdominal subcutaneous fat mass and BMI were unrelated to any CD4⁺ T cell cytokine. In conclusion, lower responsiveness of CD4⁺ T cell cytokines associated with abdominal visceral fat mass is a novel finding late in gestation.     

Central visfatin potentiates glucose-stimulated insulin secretion and β-cell mass without increasing serum visfatin levels in diabetic rats

IntroductionOur previous study revealed that plasma visfatin levels were lower in pregnant women with gestational diabetes (GDM) than non-GDM independent of prepreganacy BMI. We examined whether central visfatin modulates energy and glucose homeostasis via altering insulin resistance, insulin secretion or islet morphometry in diabetic rats.MethodsPartial pancreatectomized, type 2 diabetic, rats were interacerbroventricularly infused with visfatin (100 ng/rat/day, Px-VIS), visfatin + visfatin antagonist, CHS-828 (100 μg/rat/day, Px-VIS-ANT), or saline (control, Px-Saline) via osmotic pump, respectively, for 4 weeks.ResultsCentral visfatin improved insulin signaling (pAkt → pFOXO-1) but not pSTAT3 in the hypothalamus. Central visfatin did not alter serum visfatin levels in diabetic rats whereas the levels were higher in non-diabetic rats than diabetic rats. Body weight at the 2nd week was lowered in the Px-VIS group due to decreased food intake in the first two weeks compared to the Px-Saline group and energy expenditure was not significantly different among the treatment groups of diabetic rats. Visfatin antagonist treatment nullified the central visfatin effect. Px-VIS increased whole body glucose disposal rates in euglycemic hyperinsulinemic clamp compared to Px-Saline and lowered hepatic glucose output, whereas Px-VIS-ANT blocked the visfatin effect on insulin resistance (P < 0.05). In hyperglycemic clamp study, the area under the curve of insulin in first and second phase were significantly higher in the Px-VIS group than the Px-Saline group without modifying insulin sensitivity at the hyperglycemic state, whereas the increase in serum insulin levels was blocked in the Px-VIS-ANT group. Central visfatin also increased β-cell mass by increasing β-cell proliferation.ConclusionsCentral visfatin improved glucose homeostasis by increasing insulin secretion and insulin sensitivity at euglycemia through the hypothalamus in diabetic rats. Therefore, visfatin is a positive modulator of glucose homeostasis by delivering the hypothalamic signals into the peripheries.     

The Quételet index revisited in children and adults

BackgroundThe body mass index (BMI) is based on the original concept that body weight increases as a function of height squared. As an indicator of obesity the modern BMI assumption postulates that adiposity also increases as a function of height in states of positive energy balance.ObjectiveTo evaluate the BMI concept across different adiposity magnitudes, in both children and adults.MethodsWe studied 975 individuals who underwent anthropometric evaluation: 474 children and 501 adults. Tetrapolar bioimpedance analysis was used to assess body fat and lean mass.ResultsBMI significantly correlated with percentage of body fat (%BF; children: r = 0.893; adults: r = 0.878) and with total fat mass (children: r = 0.967; adults: r = 0.953). In children, body weight, fat mass, %BF and waist circumference progressively increased as a function of height squared. In adults body weight increased as a function of height squared, but %BF actually decreased with increasing height both in men (r = −0.406; p < 0.001) and women (r = −0.413; p < 0.001). Most of the BMI variance in adults was explained by a positive correlation of total lean mass with height squared (r² = 0.709), and by a negative correlation of BMI with total fat mass (r = −0.193).ConclusionsBody weight increases as a function of height squared. However, adiposity progressively increases as a function of height only in children. BMI is not an ideal indicator of obesity in adults since it is significantly influenced by the lean mass, even in obese individuals.     

Anthropometric and body composition characteristics during pregnancy: A study from West Bengal,India

The present cross-sectional study was aimed at investigating changes in anthropometric, body composition and blood pressure characteristics during pregnancy. A total of 406 healthy, pregnant women aged between 16 and 33 years participated in the study. Pregnant women were recruited from the outpatient department of the two-referral hospital in Bolpur subdivision of Birbhum district, West Bengal, India. Anthropometric measures such as height, weight, three circumferences and skinfold thickness at four sites (biceps, triceps, subscapular and suprailaic) were obtained using standard techniques. Percentages of body fat (%BF), intra abdominal visceral fat (IVF), basal metabolic rate (BMR) and body mass index (BMI) were measured using an Omron body fat analyser. Two forenoon blood pressure measurements were also taken and averaged for analysis. Subjects were categorized into three trimester groups: Group I, n = 30; Group II, n = 163; and Group III, n = 213. ANOVA with Scheffe's post-hoc test revealed that Group I had significantly lower mean than both Group II and Group III for systolic blood pressure and IVF, whereas Group I had significantly lower mean than Group III for BMI, BMR, %BF, diastolic blood pressure and skinfolds. The mean change in maternal weight from the first to the third trimester was merely 3 kg. Mean waist circumference varied from the first to the third trimester but not from the first to the second trimester. Furthermore, significantly increased systolic and diastolic blood pressure was observed across the trimesters. However, longitudinal studies involving interaction of body fat topography and pregnancy-induced hormones are required to further our understanding of gestation mechanism.     

High leptin/adiponectin ratio and serum triglycerides are associated with an "at-risk" phenotype in young severely obese patients

"At-risk" severely obese subjects are characterized by insulin resistance, and higher visceral fat and plasma lipid levels compared with metabolically healthy obese (MHO) subjects, although both groups have a high BMI and fat mass. The aim of this study was to measure several serum adipokines and gastrointestinal hormones in a young severely obese population from Southern Italy to identify biochemical markers of the "at-risk" insulin-resistant obese profile. We studied 160 unrelated white young adults (mean age = 25.2 years, mean BMI = 44.9 kg/m(2), 65% women) affected by obesity for at least 5 years. Serum concentrations of glucagon, ghrelin, gastric inhibitory peptide, glucagon like peptide-1, interleukin-6, tumor necrosis factor α, leptin, adiponectin, adipsin, and visfatin were measured. The leptin/adiponectin (L/A) ratio and fatty liver index (FLI) were calculated. We found a prevalence of 21.3% of MHO patients in our young severely obese patients. At univariate analysis, the "at-risk" group had higher mean levels of BMI (P < 0.0001), leptin (P = 0.039, men) and the L/A ratio (P = 0.003), and lower mean levels of visfatin (P = 0.026) than the MHO group. The L/A ratio, serum triglycerides, and male sex were significantly associated with "at-risk" obesity and accounted for 19.5% of insulin resistance at multivariate analysis. In conclusion, we demonstrate that a high serum L/A ratio and high levels of serum triglycerides may be markers of "at-risk" obesity, independent of waist circumference (WC) and BMI, in young severely obese population.     

Serum Uric Acid Levels and Risk of Metabolic Syndrome in Healthy Adults

ObjectiveTo investigate the relationship between hyperuricemia and metabolic syndrome in a population of healthy subjects.MethodsWe studied 1,573 healthy adults (25 to 64 years old) in the population laboratory of the Tehran University of Medical Sciences. The study was designed according to the World Health Organization MONICA (Multinational Monitoring of Trends and Determinants in Cardiovascular Disease) project with use of the National Cholesterol Education Program Adult Treatment Panel III criteria for metabolic syndrome.ResultsThe crude prevalence of the metabolic syndrome was 29.9% (age-adjusted, 27.5%). The rate of metabolic syndrome significantly increased in higher quartiles of serum uric acid in both sexes but especially in women (P < .0001 versus P = .026). The bivariate correlation was significant between uric acid levels and age, total serum cholesterol, high-density lipoprotein cholesterol, triglycerides, body mass index, waist and hip circumferences, waist-to-hip ratio, and systolic and diastolic blood pressures; however, there was not a significant correlation between serum uric acid concentrations and fasting plasma glucose.ConclusionThese data indicate that an independent relationship exists between hyperuricemia and the metabolic syndrome. Moreover, hyperuricemia is significantly correlated with hypertriglyceridemia, hypertension, and visceral obesity. Early detection of hyperuricemia seems to be essential for prevention of the metabolic syndrome. (Endocr Pract. 2008;14:298-304)     

Visfatin levels in prepubertal children born small or large for gestational age

Children born small (SGA) or large (LGA) for gestational age are prone to develop insulin resistance (IR) during childhood. Visfatin, a hormone with insulin-mimetic actions, has been associated with IR. This study was designed to examine whether serum level of visfatin is correlated with metabolic indices of IR, in prepuberty in association with the intrauterine growth pattern. The following parameters were evaluated at a mean age of 6.5±1.2 years in 155 prepubertal children born appropriate for the gestational age (AGA) (n=63), or SGA (n=42), or LGA (n=50): serum levels of visfatin, adiponectin, leptin, fasting glucose (G(F)) and insulin (I(F)), the homeostasis model assessment IR index (HOMA-IR), plasma lipids, anthropometric indices at birth and the time of evaluation, and obesity indices [waist circumference (WC), body mass index (BMI) and skinfold thickness]. The mean serum level of visfatin was lower in the SGA than in the AGA and the LGA children (9±5.2 vs. 11.8±5.1 and 12.7±5.6?ng/ml, respectively, p<0.01). Girls had lower visfatin levels than boys (10.4±4.3?ng/ml vs. 12.5±6.7?ng/ml, p<0.05). Visfatin was not correlated with IR indices. In multiple regression analysis visfatin level was positively correlated with birth weight z-score (t=2.56, beta=0.24, p<0.01) and crown to heel z-score (t=2.46, beta=0.22, p=0.014), independent of age, gender, maternal weight before pregnancy, maternal weight gain during pregnancy, BMI z-score, WC z-score, serum leptin and adiponectin, and HOMA-IR. In conclusion serum visfatin level was lower in prepubertal SGA children but not correlated with IR indices. Low birth weight was an independent predictor of visfatin level.     

High frequency body mass measurement,feedback, and health behaviors

We analyze weight and fat percentage measurements of respondents in an online general population panel in the Netherlands, collected using wireless scales, with an average frequency of 1.6 measurements per week. First, we document the existence of a weekly cycle; body mass is lowest on Fridays and highest on Mondays, showing significant (p < 0.01) differences of, on average, 0.2 kilogram in weight, 0.06 in BMI value, and 0.03 in fat percentage. Second, we find that in the general population fat-based measures of obesity point at a three times larger prevalence of obesity (53%) than BMI-based measures (17%). Third, we find that feedback that includes a recommended weight range increases the temporal variation in individual body mass by almost ten percent (sd for weight increases from 1.13 to 1.22; sd for BMI increases from 0.37 to 0.41; sd for fat percentage increases from 0.55 to 0.61.     

Association of serum amyloid A levels with adipocyte size and serum levels of adipokines: Differences between men and women

The aim of this study was to characterize the association between adipocyte enlargement and circulating levels of serum amyloid A (SAA). Furthermore, we wanted to search for possible associations with measures of glycemic control and levels of circulating adipokines and/or inflammatory markers in men and women with a large range in body mass index. The study cohort consisted of 167 subjects, 114 non-diabetic and 53 with Type 2 diabetes. Adipocyte diameter as well as circulating levels of SAA, C-reactive protein (CRP), adiponectin, leptin, interleukin-6, tumor necrosis factor alpha, glucose and insulin were measured. Women had higher serum levels of SAA than men (p = 0.044). SAA levels were weakly but positively correlated with BMI (p = 0.043) and % body fat (p = 0.027) in all subjects as well as subcutaneous adipocyte diameter (p = 0.034) in women. Furthermore, in all subjects we found correlations between SAA levels and levels of CRP (p < 0.001), interleukin-6 (p < 0.001), leptin (p = 0.003), insulin (p = 0.006), HbA1c (p = 0.02) and HOMA-IR (p = 0.002). A majority of the correlations were strongest in women. In conclusion, serum levels of SAA are strongly correlated with serum levels of inflammatory markers as well as measures of glycemic control. There seems to be large sex differences in these associations suggesting that sex-specific factors need to be considered when analyzing SAA levels in relation to metabolic disease.     

Evaluation of Para- and Perirenal Fat Thickness and its Association with Metabolic Disorders in Polycystic Ovary Syndrome

Objective: The aim of this study was to compare para- and perirenal fat (PFT) and subcutaneous abdominal fat (SFT) measurements between patients with polycystic ovary syndrome (PCOS) and control subjects and to assess the possible relation with metabolic disorders.Methods: This study included 68 patients with PCOS and 40 age- and body mass index (BMI)-matched healthy controls. We evaluated anthropometric, hormonal, and metabolic parameters, and abdominal ultrasonography was performed to measure PFT and SFT.Results: The mean PFT values were 6.1 ± 2.9 mm in patients with PCOS and 4.3 ± 2.3 mm in healthy controls (P = .002). SFT values were also higher in the patient group (9.6 ± 5 mm) compared to healthy subjects (3.5 ± 0.5 mm) (P = .017). A significant positive correlation was found between PFT and BMI (r = 0.368), waist circumference (WC) (r = 0.441), Ferriman-Gallwey (FG) score (r = 0.313), blood pressure (systolic, SBP, r = 0.213; diastolic, DBP, r = 0.215), plasma glucose (r = 0.195), homeostasis model assessment-insulin resistance (HOMA-IR, r = 0.273), SFT (r = 0.555). Conversely, negative correlations were found between PFT and estradiol (r = -0.218) and sex hormone-binding globulin (SHBG, r = -0.304). Nonobese PCOS patients (6.1 ± 3.07 mm) had higher PFT values than nonobese controls (3.47 ± 1.5 mm); however, SFT measurements did not differ (P = .086). In multiple linear regression analysis, SFT (P = .006) was a significant and independent predictor for PFT, along with WC (P = .023). In a stepwise model, SFT was the predictor of PFT (P = .001).Conclusion: PFT values were higher particularly in nonobese PCOS patients compared to nonobese control subjects. There was a significant interaction between PCOS and obesity on PFT.Abbreviations: BMI = body mass index; CT = computed tomography; DBP = diastolic blood pressure; FPG = fasting plasma glucose;; HDL-cholesterol = high-density lipoprotein cholesterol; HOMA-IR = homeostasis model assessment-insulin resistance; hsCRP = high-sensitivity C-reactive protein; LDL-cholesterol = low-density lipoprotein cholesterol; LH = luteinizing hormone; NCAH = nonclassic congenital adrenal hyperplasia; 17-OHP = 17-hydroxyprogesterone; PCOS = polycystic ovary syndrome; PFT = para- and perirenal fat; SAT = subcutaneous abdominal adipose tissue; SBP = systolic blood pressure; SFT = abdominal subcutaneous fat thickness; TG = triglyceride; US = ultrasound; VAT = visceral abdominal adipose tissue; WC = waist circumference     

Xanthohumol lowers body weight and fasting plasma glucose in obese male Zucker fa/fa rats

Obesity contributes to increased risk for several chronic diseases including cardiovascular disease and type 2 diabetes. Xanthohumol, a prenylated flavonoid from hops (Humulus lupulus), was tested for efficacy on biomarkers of metabolic syndrome in 4 week old Zucker fa/fa rats, a rodent model of obesity. Rats received daily oral doses of xanthohumol at 0, 1.86, 5.64, and 16.9 mg/kg BW for 6 weeks. All rats were maintained on a high fat (60% kcal) AIN-93G diet for 3 weeks to induce severe obesity followed by a normal AIN-93G (15% kcal fat) diet for the last 3 weeks of the study. Weekly food intake and body weight were recorded. Plasma cholesterol, glucose, insulin, triglyceride, and monocyte chemoattractant protein-1 (MCP-1) levels were assessed using commercial assay kits. Plasma and liver tissue levels of XN and its metabolites were determined by liquid–chromatography tandem mass spectrometry. Plasma and liver tissue levels of xanthohumol were similar between low and medium dose groups and significantly (p < 0.05) elevated in the highest dose group. There was a dose-dependent effect on body weight and plasma glucose levels. The highest dose group (n = 6) had significantly lower plasma glucose levels compared to the control group (n = 6) in male but not female rats. There was also a significant decrease in body weight for male rats in the highest dose group (16.9 mg/kg BW) compared to rats that received no xanthohumol, which was also not seen for female rats. Plasma cholesterol, insulin, triglycerides, and MCP-1 as well as food intake were not affected by treatment. The findings suggest that xanthohumol has beneficial effects on markers of metabolic syndrome.     

Plasma visfatin,associated with a genetic polymorphism −1535C > T,is correlated with C-reactive protein in Chinese Han patients with traumatic brain injury

Visfatin is a newly identified pro-inflammatory adipokine and a genetic polymorphism −1535 C > T located in the visfatin gene promoter has been suggested to be associated with the regulation of visfatin expression in some inflammatory illness. However, there were some conflicting results regarding whether this variant is functional or not. This study aimed to examine the relations of the −1535 C > T single nucleotide polymorphism (SNP) of visfatin gene to the plasma visfatin and C-reactive protein concentrations in traumatic brain injury (TBI). 318 Chinese Han patients with TBI were recruited in this study. Plasma visfatin and C-reactive protein levels were significantly different between the genotypes in the SNP-1535 C > T even after adjustment for age, sex and body mass index. The genotype C–C had the highest plasma visfatin and C-reactive protein concentrations. The plasma visfatin and C-reactive protein concentrations between the variant genotypes C–T and T–T did not differ significantly. Plasma visfatin level was significantly associated with plasma C-reactive protein level using multivariate linear regression. Thus, the SNP-1535 C > T of visfatin gene seemed to be potentially involved in the inflammatory component of TBI through a decreased production of visfatin.     

Traditional Anthropometric Parameters Still Predict Metabolic Disorders in Women With Severe Obesity

It is well established that fat distribution rather than the total quantity of fat is the major determinant of cardiovascular risk in overweight subjects. However, it is not known whether the concept of fat distribution still makes sense in severely obese subjects. Particularly, the role of visceral fat accumulation and/or of adipocyte hypertrophy in insulin resistance (IR) has not been studied in this population. Therefore, the aim of this study was to clarify the determinants of metabolic disorders in severely obese women. We performed a cross‐sectional study in 237 severely obese women (BMI >35 kg/m²). We assessed total body fat mass and fat distribution by anthropometric measurements (BMI and waist‐to‐hip ratio (WHR)) and by dual‐energy X‐ray absorptiometry (DXA). In 22 women, we measured subcutaneous and visceral adipocyte size on surgical biopsies. Mean BMI was 44 ± 7 kg/m² (range 35–77), mean age 37 ± 11 years (range 18–61). Lipid parameters (triglycerides, high‐density lipoprotein cholesterol) and IR markers (fasting insulin and homeostasis model assessment (HOMA) index) correlated with fat distribution, whereas inflammatory parameters (C‐reactive protein, fibrinogen) correlated only with total fat mass. An association was observed between android fat distribution and adipocyte hypertrophy. Visceral adipocyte hypertrophy was associated with both IR and hypertension, whereas subcutaneous fat‐cell size was linked only to hypertension. Our results obtained in a large cohort of women showed that fat distribution still predicts metabolic abnormalities in severe obesity. Furthermore, we found a cluster of associations among fat distribution, metabolic syndrome (MS), and adipocyte hypertrophy.     

Human Immunodeficiency Virus-Associated Lipodystrophy: An Objective Definition Based on Dual-Energy X-RAY Absorptiometry-Derived Regional Fat Ratios In A South Asian Population

ObjectiveTo develop an objective definition of human immunodeficiency virus (HIV)-associated lipodystrophy by using regional fat mass ratios and to assess the utility of anthropometric and skinfold measurements in the initial screening for lipodystrophy.MethodsMale patients between 25 and 50 years old with proven HIV infection (highly active antiretroviral therapy [HAART]-naïve subjects and those receiving successful HAART) were studied and compared with body mass index (BMI)-matched HIV-negative control subjects. Anthropometric variables, body composition, dual-energy x-ray absorptiometry findings, and metabolic variables were compared among the 3 study groups and between those patients with and those without lipodystrophy.ResultsTrunk fat/lower limb fat mass ratio > 2.28 identified 54.3% of patients with HIV receiving HAART as having lipodystrophy and had the highest odds ratio for predicting metabolic syndrome. The “clinical diagnosis of many false-positive and false-negative results. Triceps skinfold thickness (SFT)/BMI ratio ≤ 0.49 and abdominal SFT/triceps SFT ratio > 1.385 have good sensitivity but poor specificity in identifying lipodystrophy. In comparison with HAART-naïve patients with HIV, those receiving HAART had significantly higher insulin resistance, and a significantly greater proportion had impaired glucose tolerance and dyslipidemia. Among patients receiving HAART, those with lipodystrophy had a greater degree of insulin resistance, higher triglyceride levels, and lower levels of high-density lipoprotein cholesterol.ConclusionThe trunk fat/lower limb fat mass ratio in BMI-matched normal subjects can be used to derive cutoff values to define lipodystrophy objectively in HIV-infected patients. Defining lipodystrophy in this way is better than other methods of identifying those patients with increased cardiovascular risk. Triceps SFT/BMI and abdominal SFT/ triceps SFT ratios may be useful as screening tools in resource-poor settings. (Endocr Pract. 2012;18:158-169)     

Particular characteristics of the metabolic syndrome in patients with morbid obesity

BackgroundCriteria for the diagnosis of the metabolic syndrome are currently being reconsidered, as their usefulness is not the same for all phenotypes in relation to the risk of cardiovascular disease.AimWe analyzed the changes in metabolic parameters after a fat overload in different groups of patients.Materials and methodsThe study included 20 healthy persons, 30 metabolic syndrome patients without morbid obesity, 80 metabolic syndrome patients with morbid obesity and 16 patients with morbid obesity without the metabolic syndrome. All the participants received a fat overload of 60 g. Measurements were made before the overload and 3 h afterwards of triglycerides, free fatty acids, insulin and uric acid.ResultsMetabolic syndrome patients with morbid obesity had a lower waist-to-hip ratio, and lower plasma free fatty acid and triglycerides levels at baseline and after the overload than patients without morbid obesity. Plasma uric acid levels rose after the fat overload in the metabolic syndrome patients who had morbid obesity but not in the patients without morbid obesity. A positive relation was found between plasma triglycerides and free fatty acid levels in all the patients but not in the controls after the fat overload. A positive relation was also found between uric acid and insulin levels in the metabolic syndrome patients with morbid obesity.ConclusionsMetabolic syndrome patients with and without morbid obesity presented different metabolic characteristics. This suggests that there are 2 different clinical phenotypes, both grouped under the metabolic syndrome umbrella.     

In urban South Africa, 16 year old adolescents experience greater health equality than children

Despite the strongly established link between socio-economic status (SES) and health across most stages of the life-course, the evidence for a socio-economic gradient in adolescent health outcomes is less consistent. This paper examines associations between household, school, and neighbourhood SES measures with body composition outcomes in 16 year old South African Black urban adolescents from the 1990 born Birth to Twenty (Bt20) cohort. Multivariable regression analyses were applied to data from a sub-sample of the Bt20 cohort (n = 346, 53% male) with measures taken at birth and 16 years of age to establish socio-economic, biological, and demographic predictors of fat mass, lean mass, and body mass index (BMI). Results were compared with earlier published evidence of health inequality at ages 9–10 years in Bt20. Consistent predictors of higher fat mass and BMI in fully adjusted models were being female, born post term, having a mother with post secondary school education, and having an obese mother. Most measures of SES were only weakly associated with body composition, with an inconsistent direction of association. This is in contrast to earlier findings with Bt20 9–10 year olds where SES inequalities in body composition were observed. Findings suggest targeting obesity interventions at females in households where a mother has a high BMI.     

The ghrelin activating enzyme ghrelin-O-acyltransferase (GOAT) is present in human plasma and expressed dependent on body mass index

Ghrelin is the only known peripherally produced and centrally acting peptide hormone stimulating food intake. The acylation of ghrelin is essential for binding to its receptor. Recently, the ghrelin activating enzyme ghrelin-O-acyltransferase (GOAT) was identified in mice, rats and humans. In addition to gastric mucosal expression, GOAT was also detected in the circulation of rodents and its expression was dependent on metabolic status. We investigated whether GOAT is also present in human plasma and whether expression levels are affected under different conditions of body weight. Normal weight, anorexic and obese subjects with body mass index (BMI) 30–40, 40–50 and >50 were recruited (n = 9/group). In overnight fasted subjects GOAT protein expression was assessed by Western blot and ghrelin measured by ELISA. GOAT protein was detectable in human plasma. Anorexic patients showed reduced GOAT protein levels (−42%, p < 0.01) whereas obese patients with BMI > 50 had increased concentrations (+34%) compared to normal weight controls. Ghrelin levels were higher in anorexic patients compared to all other groups (+62–78%, p < 0.001). Plasma GOAT protein expression showed a positive correlation with BMI (r = 0.71, p < 0.001) and a negative correlation with ghrelin (r = −0.60, p < 0.001). Summarized, GOAT is also present in human plasma and GOAT protein levels depend on the metabolic environment with decreased levels in anorexic and increased levels in morbidly obese patients. These data may indicate that GOAT counteracts the adaptive changes of ghrelin observed under these conditions and ultimately contributes to the development or maintenance of anorexia and obesity as it is the only enzyme acylating ghrelin.     

Fasting suppresses T cell-mediated immunity in female Mongolian gerbils (Meriones unguiculatus)

Immune defense is important for organisms' survival and fitness. Small mammals in temperate zone often face seasonal food shortages. Generally fasting can suppress immune function in laboratory rodents and little information is available for wild rodents. The present study tested the hypothesis that Mongolian gerbils (Meriones unguiculatus) could inhibit T cell-mediated immunity to adapt to acute fasting. Forty-two females were divided into the fed and fasted groups, in which the latter was deprived of food for 3 days. After 66 h fasting, half of the gerbils in each group were injected with phosphate buffered saline or phytohaemagglutinin (PHA) solution. T cell-mediated immunity assessed by PHA response was suppressed in the fasted gerbils compared with the fed gerbils. The fasted gerbils had lower body fat mass, wet and dry thymus mass, dry spleen mass, white blood cells, serum leptin and blood glucose concentrations, but higher corticosterone concentrations than those of the controls. Moreover, PHA response was positively correlated with body fat mass and serum leptin levels in the immunochallenged groups. Taken together, acute fasting leads to immunosuppression, which might be caused by low body fat mass and low serum leptin concentrations in female Mongolian gerbils.     

Efecto metabólico del ejercicio físico regular en la población sana

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