The effect of endurance and endurance-strength training on body composition and cardiometabolic markers in abdominally obese women: a randomised trial

Studies comparing the effect of endurance and endurance-strength training on cardiometabolic markers provided inconsistent results. Therefore, the study aimed to compare the effect of endurance and endurance-strength training on body composition and cardiometabolic parameters in abdominally obese women. In this randomised trial, 101 subjects were included and divided into endurance (n = 52) and endurance-strength (n = 49) training. During the 12-week intervention, participants performed supervised one-hour training three times a week. Body composition, blood pressure (BP), markers of glucose and lipid homeostasis, and myoglobin levels were measured before and after the intervention. In total, 85 subjects completed the trial. Both interventions decreased fat mass and visceral adipose tissue and increased free fat mass, appendicular lean mass index and lean mass index. Neither endurance training nor endurance-strength training affected glucose and lipid metabolism. However, only endurance training significantly decreased paraoxonase and myoglobin levels. Both training programmes significantly decreased BP, with a more reduction of diastolic BP noted in the endurance group. In conclusion, both training programmes had a favourable effect on body composition but did not improve glucose and lipid homeostasis. Besides, endurance training decreased paraoxonase activity and myoglobin levels and was more effective in reducing BP.The study was registered with the German Clinical Trials Register (DRKS) within the number: DRKS00019832 (retrospective registration), date of registration: 26/02/2020.

The effect of 580 nm-based-LED mixed light on growth, adipose deposition, skeletal development, and body temperature of chickens

Though previous study indicated that the 580 nm-yellow-LED-light showed an stimulating effect on growth of chickens, the low luminous efficiency of the yellow LED light cannot reflect the advantage of energy saving. In present study, the cool white LED chips and yellow LED chips have been combined to fabricate the white × yellow mixed LED light, with an enhanced luminous efficiency. A total 300 newly hatched chickens were reared under various mixed LED light. The results indicated that the white × yellow mixed LED light had "double-edged sword" effects on bird's body weight, bone development, adipose deposition, and body temperature, depending on variations in ratios of yellow component. Low yellow ratio of mixed LED light (Low group) inhibited body weight, whereas medium and high yellow ratio of mixed LED light (Medium and High groups) promoted body weight, compared with white LED light (White group). A progressive change in yellow component gave rise to consistent changes in body weight over the entire experiment. Moreover, a positive relationship was observed between yellow component and feed conversion ratio. High group-treated birds had greater relative abdominal adipose weight than Medium group-treated birds (P = 0.048), whereas Medium group-treated birds had greater relative abdominal adipose weight than Low group-treated birds (P = 0.044). We found that mixed light improved body weight by enhancing skeletal development (R² = 0.5023, P = 0.0001) and adipose deposition (R² = 0.6012, P = 0.0001). Birds in the Medium, High and Yellow groups attained significantly higher surface temperatures compared with the White group (P = 0.010). The results suggest that the application of the mixed light with high level of yellow component can be used successfully to improve growth and productive performance in broilers.

Effect of small-sided team sport training and protein intake on muscle mass, physical function and markers of health in older untrained adults: A randomized trial

The effect of small-sided team sport training and protein intake on muscle mass, physical function, and adaptations important for health in untrained older adults was examined. Forty-eight untrained older (72±6 (±standard deviation, SD) years men and women were divided into either a team sport group ingesting a drink high in protein (18 g) immediately and 3 h after each training session (TS-HP, n = 13), a team sport group ingesting an isocaloric drink with low protein content (3 g; TS-LP, n = 18), or a control group continuing their normal activities (CON, n = 17). The team sport training was performed as ~20 min of small-sided ball games twice a week over 12 weeks. After the intervention period, leg muscle mass was 0.6 kg higher (P = 0.047) in TS-HP, with no effect in TS-LP. In TS-HP, number of sit-to-stand repetitions increased (1.2±0.6, P = 0.054), time to perform 2.45 m up-and-go was lower (0.7±0.3 s, P = 0.03) and number of arm curl repetitions increased (3.5±1.2, P = 0.01), whereas in TS-LP only number of repetitions in sit-to-stand was higher (1.6±0.6, P = 0.01). In TS-LP, reductions were observed in total and abdominal fat mass (1.2±0.5 and 0.4±0.2 kg, P = 0.03 and P = 0.02, respectively), heart rate at rest (9±3 bpm, P = 0.002) and plasma C-reactive protein (1.8±0.8 mmol/L, P = 0.03), with no effects in TS-HP. Thus, team sport training improves functional capacity of untrained older adults and increases leg muscle mass only when ingesting proteins after training. Furthermore, team sport training followed by intake of drink with low protein content does lower fat mass, heart rate at rest and level of systemic inflammation.

Trial Registration: clinicaltrials.gov NCT03120143

Effects of cryolipolysis on abdominal adiposity of women

　　BACKGROUND: The cryolipolysis is on the spotlight as a non-invasive method which reduces fat layer thickness with no damage to surrounding tissues.

OBJECTIVE

This study aims to verify the effectiveness of cryolipolysis in the reduction of localized adiposity in women.

MATERIALS AND METHODS

This is an experimental study, without a control group, with pre- and post- treatment evaluation through a single application on the lower abdominal area.

SETTING

Research conducted in the period from July to December 2015 at the University Potiguar.

PARTICIPANTS

A group of 15 women, age between 25-50 years. The cryolipolysis was used in the following parameters: temperature (-7 degree C); suction power (30 kPa), and application time (60 min).

MEASUREMENTS

After the cryolipolysis was performed, a follow-up of 2 months was conducted to verify the changes related to weight, body circumference, fat layer thickness, which were evaluated by ultrasonography and photogrammetry.

RESULTS

From data analysis, the reductions observed on perimeter (p=0.03) and ultrasonography (p=0.03) showed significant results, considering p <0.05. As of body weight results (p=0.57), the average value varied during the study; however, at the end of the research, no significant weight increase or decrease was reported, as it is known that this method does not interfere with this variable. Additionally, quantitative data were satisfactory. The photogrammetry analysis showed that cryolipolysis positively affected subjects' results.

CONCLUSION

A change in body contouring, especially in individuals with lower body mass, reinforces the idea that the parameters must be suitable for individual needs.

Obesity, Muscular Strength, Muscle Composition and Physical Performance in an Elderly Population

OBJECTIVE

To evaluate the association between BMI levels, muscular strength, muscle composition and physical performance in the elderly.

DESIGN

Italians subjects from the Progetto Veneto Anziani (ProVA) study were analyzed.

SETTING

The ProVa was a population study focused on chronic diseases and functional limitations in Italian subjects aged ≥65 years living in two Northeast Italian cities.

PARTICIPANTS

The ProVa study included 3099 subjects. ProVa participants with unknown information on BMI or disability status were excluded. The final sample was thus represented by 1.188 men, and 1.723 women.

MEASUREMENTS

Physical performance was measured with the Short Physical Performance Battery (SPPB) and leg muscular strength with dynamometry. Fat distribution and skeletal muscle composition were measured in an abdominal single-scan magnetic resonance (MRI) in a randomly selected sample of 348 subjects. Study population was stratified by BMI classes.

RESULTS

An association between BMI levels and SPPB was observed. Normal weight subjects showed the best SPPB scores (8.29±0.03), with significant differences compared to underweight (7.50±0.15; p<0.001), overweight (8.12±0.02; p<0.001), class I (7.72±0.04; p<0.001), class II (6.67±0.09; p<0.001) and class III obesity (5.88±0.24; p<0.001). This pattern was not modified by adjustment for possible confounders. Compared to normal weight subjects (22.9±0.1 kg), leg muscular strength was higher in overweight (23.8±0.1; p<0.001) and in class I obesity (24.5±0.1; p<0.001), but it was reduced in class II (21.4±0.3; p<0.001) and class III (19.8±0.9; p<0.001). The association between BMI and impaired physical performance was not affected by adjustment for muscular strength. An inverse association between SPPB scores and fat infiltration in skeletal muscle was observed in patients with abdominal MRI.

CONCLUSION

A poor physical performance was observed in overweight and obese elderly subjects. Leg strength was reduced only in subjects with severe obesity. Physical performance was negatively influenced by the degree of fat infiltration in skeletal muscle.

The α' subunit of β-conglycinin and the A1-5 subunits of glycinin are not essential for many hypolipidemic actions of dietary soy proteins in rats

PURPOSE

This study examined the effects of dietary soy protein (SP) lacking different storage protein subunits and isoflavones (ISF) on the abdominal fat, blood lipids, thyroid hormones, and enzymatic activities in rats.

METHODS

Weanling Sprague-Dawley rats (8 males and 8 females/group) were fed diets containing either 20 % casein without or with supplemental isoflavones or alcohol-washed SP isolate or SP concentrates (SPC) prepared from 6 different soy bean lines for 8 weeks.

RESULTS

Feeding of diets containing SPC regardless of their subunit compositions significantly lowered relative liver weights, blood total, free, and LDL cholesterol in both genders (P < 0.05) and also reduced serum free fatty acids (FFA) and abdominal fat in females (P < 0.05) compared to the casein or casein + ISF diets. Dietary SPC significantly elevated the plasma free triiodothyronine (T3) in both genders and total T3 in females compared to the casein diet (P < 0.05). The SPC lacking β-conglycinin α' and either the glycinin A1-3 or A1-5 subunits increased total T3 in males and reduced plasma enzymatic activities of creatine kinase and lactate dehydrogenase compared to casein or casein + ISF diet (P < 0.05).

CONCLUSIONS

Soy isoflavones were mainly responsible for the hypocholesterolemic effects and increased plasma free T3, whereas reduction in FFA, abdominal fat, liver weight and increased plasma total T3 were the effects of the soy proteins. Neither the α' subunit of β-conglycinin nor the A1-5 subunits of glycinin are essential for the hypolipidemic properties of soy proteins.

Central body fat changes in men affected by post-surgical hypogonadotropic hypogonadism undergoing testosterone replacement therapy are modulated by androgen receptor CAG polymorphism

BACKGROUND AND AIMS

Little is known about the effect of androgen receptor (AR) gene CAG repeat polymorphism in conditioning body composition changes after testosterone replacement therapy (TRT). In this study, we aimed to clarify this aspect by focussing our attention on male post-surgical hypogonadotropic hypogonadism, a condition often associated with partial or total hypopituitarism.

METHODS AND RESULTS

Fourteen men affected by post-surgical hypogonadotropic hypogonadism and undergoing several replacement hormone therapies were evaluated before and after TRT. Dual-energy X-ray absorptiometry (DEXA)-derived body composition measurements, pituitary-dependent hormones and AR gene CAG repeat polymorphism were considered. While testosterone and insulin-like growth factor-1 (IGF-1) levels increased after TRT, cortisol concentration decreased. No anthropometric or body composition parameters varied significantly, except for abdominal fat decrease. The number of CAG triplets was positively and significantly correlated with this abdominal fat decrease, while the opposite occurred between the latter and Δ-testosterone. No correlation of IGF-1 or cortisol variation (Δ-) with Δ-abdominal fat was found. At multiple linear regression, after correction for Δ-testosterone, the positive association between CAG triplet number and abdominal fat change was confirmed.

CONCLUSIONS

In male post-surgical hypogonadotropic hypogonadism, shorter length of AR CAG repeat tract is independently associated with a more marked decrease of abdominal fat after TRT.

The relationship of morphology and motor abilities to specific table tennis tasks in youngsters

The aim of this research was to establish the relationship of certain basic motor abilities and morphological characteristics and efficacy in specific table tennis tasks. The research sample consisted of cadet category table tennis players (N = 101; aged 10.52 +/- 0.78 years, training experience 2.8 +/- 0.93 years). The participants were measured as they performed 24 motor tasks, along with 15 anthropometric measures and 3 specific table tennis tests. Indicators of the relationship between morphological characteristics and motor abilities, coupled with the results of the specific table tennis tests indicate that: a) subcutaneous fatty tissue on the lower extremities significantly limits the test results where movements involving fast changes in direction are required; b) subcutaneous abdominal adipose tissues have a positive influence on tasks demanding controlled and precise alternate bouncing of the ball; c) in general, a positive influence can be seen in the results of specific tests concerning the following motor abilities: arm coordination, agility, explosive arm power, movement frequency speed and repetitive leg power. The test used for a coordination assessment of the whole body revealed a negative influence on the success of performing specific tasks.

Antiobesity effect of Gynostemma pentaphyllum extract (actiponin): a randomized, double-blind, placebo-controlled trial

OBJECTIVE

The effects of actiponin was investigated, a heat-processed Gynostemma pentaphyllum extract, on body weight, fat loss, and metabolic markers of Korean participants in a 12-week, randomized, double-blind, placebo-controlled clinical trial.

DESIGN AND METHODS

Obese participants (BMI ≥ 25 kg m(-2) and WHR ≥ 0.90 for male or WHR ≥ 0.85 for female) who had not been diagnosed with any disease and met the inclusion criteria were recruited for this study. The 80 subjects were randomly divided into actiponin (n = 40, 450 mg day(-1) ) and placebo (n = 40) groups. Outcomes included measurement of efficacy (abdominal fat distribution, anthropometric parameters, and blood lipid profiles) and safety (adverse events, laboratory test results, electrocardiogram data, and vital signs).

RESULTS

During 12-week of actiponin supplementation, total abdominal fat area, body weight, body fat mass, percent body fat, and BMI were significantly decreased (P = 0.044, P < 0.05, P < 0.0001, P < 0.0001, and P < 0.05, respectively) in the actiponin group compared to the placebo group. No clinically significant changes in any safety parameter were observed.

CONCLUSION

Our study revealed that actiponin is a potent antiobesity reagent that does not produce any significant adverse effects. These results suggest that actiponin supplementation may be effective for treating obese individuals.

Imaging and estimation of human abdominal fat by electrical impedance tomography using multiple voltage measurement patterns

A measuring device for human abdominal fat from the conductivity image derived by electrical impedance tomography (EIT) is rarely found. This study was aimed to reconstruct precise conductivity images from multiple voltage measurements in different patterns of the combination of current and voltage electrodes. We examined two voltage measuring patterns using electrodes located at upper and lower levels around the abdomen of a subject. In the experiment, after 1024 voltage data were taken from one specified voltage measurement pattern, another 1024 data were also taken continuously using another pattern. The reconstruction of conductivity image was made using entire data. As a result, the tomography image was improved compared with the image obtained from single voltage measurement pattern. We then obtained the histogram of the conductivities and estimated the area of abdominal fat. The present method using multiple voltage measurement patterns would be effective, if the measuring time can be much reduced through future modification of the tomography device.

Abdominal fat is associated with a greater brain reward response to high-calorie food cues in Hispanic women

OBJECTIVE

Exposure to high-calorie foods may promote overeating by stimulating brain reward pathways and appetite. Abdominal fat has particularly adverse metabolic consequences and may alter brain pathways that regulate feeding behavior. Functional magnetic resonance imaging (fMRI) was used to test the hypothesis that high-calorie food cues activate brain reward regions and increase appetite, and to examine the relationship between abdominal fat and brain reward responsiveness in Hispanic women.

DESIGN AND METHODS

fMRI was performed while 13 volunteers viewed 12 blocks of pictures of food and non-food items. Participants rated hunger and food desire after each block of pictures. Brain activation to high-calorie foods was determined by calculating a contrast of high-calorie food minus non-food images. Pearson's correlations were used to test the relationship between brain reward activation and waist circumference.

RESULTS

High-calorie food images activated brain reward regions (Z > 2.3, P < 0.05 corrected for multiple comparisons) and increased hunger (P = 0.001), desire for sweet (P = 0.012) and savory (P = 0.009) foods. The striatal response to high-calorie foods positively correlated with waist circumference, independent of BMI (r = 0.621, P = 0.031).

CONCLUSIONS

Exposure to high-calorie food images activates brain reward pathways and increases appetitive drive in Hispanic females. Abdominal fat, independent of BMI, parallels striatal responsiveness to high-calorie food images.

Fat mass, and not diet, has a large effect on postprandial leptin but not on adiponectin concentrations in cats

Leptin and adiponectin play important roles in carbohydrate and lipid metabolism in different species. Information is limited on the effects of diet, weight gain, and fat mass on their concentrations in cats. This study compared fasting and postprandial blood leptin and total adiponectin concentrations before and after 8 wk of ad libitum feeding to promote weight gain in adult cats (n = 32) fed either a low-carbohydrate, high-protein (23% and 47% ME) or a high-carbohydrate, low-protein (51% and 21% ME) diet. There were significant effects of total, abdominal, and nonabdominal fat mass, but not diet or body weight, on mean 24-h and peak leptin (P < 0.01); observed increases in mean and peak leptin were greatest for abdominal fat mass (50% and 56% increase for every extra 100 g, respectively). After weight gain, postprandial leptin concentration increased markedly relative to when cats were lean, and the duration of the increase was longer after a mean weight gain of 37% with the low-carbohydrate, high-protein diet group compared with 17% with the high-carbohydrate, low-protein group (P ≤ 0.01). Adiponectin was lower than fasting at some time points during the postprandial period in both groups (P ≤ 0.05). For both fasting and mean 24-h adiponectin, there was no significant diet effect (P ≥ 0.19) or changes in weight gain relative to when cats were lean (P ≥ 0.29). In conclusion, fat mass, and not diet, has a large effect on postprandial leptin but not adiponectin concentrations in cats.

Abdominal fat is associated with lower bone formation and inferior bone quality in healthy premenopausal women: a transiliac bone biopsy study

CONTEXT

The conventional view that obesity is beneficial for bone strength has recently been challenged by studies that link obesity, particularly visceral obesity, to low bone mass and fractures. It is controversial whether effects of obesity on bone are mediated by increased bone resorption or decreased bone formation.

OBJECTIVE

The objective of the study was to evaluate bone microarchitecture and remodeling in healthy premenopausal women of varying weights.

DESIGN

We measured bone density and trunk fat by dual-energy x-ray absorptiometry in 40 women and by computed tomography in a subset. Bone microarchitecture, stiffness, remodeling, and marrow fat were assessed in labeled transiliac bone biopsies.

RESULTS

Body mass index (BMI) ranged from 20.1 to 39.2 kg/m(2). Dual-energy x-ray absorptiometry-trunk fat was directly associated with BMI (r = 0.78, P < .001) and visceral fat by computed tomography (r = 0.79, P < .001). Compared with women in the lowest tertile of trunk fat, those in the highest tertile had inferior bone quality: lower trabecular bone volume (20.4 ± 5.8 vs 29.1 ± 6.1%; P = .001) and stiffness (433 ± 264 vs 782 ± 349 MPa; P = .01) and higher cortical porosity (8.8 ± 3.5 vs 6.3 ± 2.4%; P = .049). Bone formation rate (0.004 ± 0.002 vs 0.011 ± 0.008 mm(2)/mm · year; P = .006) was 64% lower in the highest tertile. Trunk fat was inversely associated with trabecular bone volume (r = -0.50; P < .01) and bone formation rate (r = -0.50; P < .001). The relationship between trunk fat and bone volume remained significant after controlling for age and BMI.

CONCLUSIONS

At the tissue level, premenopausal women with more central adiposity had inferior bone quality and stiffness and markedly lower bone formation. Given the rising levels of obesity, these observations require further investigation.

Ethnic and sex differences in visceral, subcutaneous, and total body fat in children and adolescents

OBJECTIVE

This study investigated ethnic and sex differences in the distribution of fat during childhood and adolescence.

DESIGN AND METHODS

A cross-sectional sample (n = 382), aged 5-18 years, included African American males (n = 84), White males (n = 96), African American females (n = 118), and White females (n = 84). Measures for total body fat (TBF) mass and abdominal adipose tissue (total volume and L4-L5 cross-sectional area) for both subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) depots were assessed by dual-energy X-ray absorptiometry and magnetic resonance image, respectively. Analyses of covariance (ANCOVAs) were used to determine ethnic and sex differences in TBF (adjusted for age) and ethnic and sex differences in SAT and VAT (adjusted for both age and TBF).

RESULTS

Age-adjusted TBF was greater in African Americans (P = 0.017) and females (P < 0.0001) compared with Whites and males, respectively. In age- and TBF-adjusted ANCOVAs, no differences were found in the SAT. The VAT volume was, however, greater in Whites (P < 0.0001) and males (P < 0.0001) compared with African Americans and females, respectively. Similar patterns were observed in SAT and VAT area at L4-L5.

CONCLUSIONS

The demonstrated ethnic and sex differences are important confounders in the prevalence of obesity and in the assignment of disease risk in children and adolescents.

Lower limbs composition and radiographic knee osteoarthritis (RKOA) in Chingford sample--a longitudinal study

Our aim in this longitudinal study was to evaluate to what extent fat and lean tissue mass variations are associated and can predict RKOA in a large sample of British women followed-up over 10 years. Kellgren/Lawrence (K/L), joint space narrowing (JSN) and osteophyte (OSP) grades were scored from radiographs of both knees in 909 middle-aged women from the Chingford registry. Body composition components were assessed using the dual energy X-ray absorptiometry (DXA) method. In cross-sectional analysis, combined effect of age, BMI and leg tissue composition was required for best fitting model explaining variations of K/L scoring and osteophytes at lateral compartment. To explain medial osteophytes, age and BMI were sufficient to generate the best fitting model. In prediction analysis, leg lean mass was the more powerful predictor of K/L, medial osteophytes than BMI. In conclusion, BMI appears to influence the development of knee OA through both fat and/or lean mass, depending on RKOA phenotype.

Ethinyl estradiol-cyproterone acetate versus low-dose pioglitazone-flutamide-metformin for adolescent girls with androgen excess: divergent effects on CD163, TWEAK receptor, ANGPTL4, and LEPTIN expression in subcutaneous adipose tissue

OBJECTIVE

The aim was to compare the effects of a traditional therapy (an oral estroprogestagen) to those of a novel treatment (a low-dose combination of generics) in adolescent girls with androgen excess.

STUDY DESIGN AND METHODS

In an open-label trial over 1 yr, 34 adolescents (age, 16 yr; body mass index, 23 kg/m2) with hyperinsulinemic androgen excess and without pregnancy risk were randomized to receive daily ethinyl estradiol-cyproterone acetate (EE-CA; Diane 35 Diario) or a low-dose combination of pioglitazone 7.5 mg/d, flutamide 62.5 mg/d, and metformin 850 mg/d (PioFluMet). Markers of androgen excess, C-reactive protein, high molecular weight adiponectin, lipids, carotid intima media thickness, body composition (absorptiometry), abdominal fat partitioning (magnetic resonance imaging), and gene expression in longitudinal biopsies of sc adipose tissue at the abdominal level (RT-PCR) were assessed at baseline and after 1 yr.

RESULTS

EE-CA and low-dose PioFluMet reduced androgen excess comparably, but had divergent effects on C-reactive protein, high molecular weight adiponectin, lipids, carotid intima media thickness, lean mass, abdominal and visceral fat, and on the expression of CD163, leptin, TNF-like weak inducer of apoptosis receptor, and angiopoietin-like protein 4, respectively, related to macrophage activation, fat accretion, inflammation, and lipoprotein metabolism in adipose tissue. All these divergences pointed to a healthier condition on low-dose PioFluMet.

CONCLUSION

EE-CA and PioFluMet are similarly effective in reversing androgen excess over 1 yr, but low-dose PioFluMet is superior in reversing inflammatory, metabolic, and cardiovascular anomalies that are often associated with androgen excess.

Relative bioavailability to laying hens of indicator polychlorobiphenyls present in soil

Transfer of indicator polychlorobiphenyls (PCBs) from soil into hen eggs may occur in hens reared outdoor, which ingest significant amounts of soil. This transfer depends on the bioavailability of the ingested compounds. The impact of soil on the bioavailability of indicator PCBs was assessed by means by a relative bioavailability (RBA) trial, in which their deposition in egg yolk and in abdominal fat, in response to their ingestion through contaminated-soil and through spiked-oil were compared. A sandy soil (709 μg indicator PCBs kg(-1) dry matter) was collected in the vicinity of a former fire involving treated wood. Twenty-eight laying hens were individually housed and fed one of the seven experimental diets during 14 d. The seven experimental diets were an uncontaminated control diet, three diets in which contaminated soil was introduced at levels of 3%, 6% and 9% and three diets in which spiked oil was introduced to achieve similar levels and profile of contaminants. Yolk, abdominal fat and liver were collected at the end of exposure. Indicator PCBs were extracted by ASE (Accelerated Solvent Extraction) and analyzed by GC-HMRS. Within each ingested matrix, the concentration of indicator PCBs in yolk and in abdominal fat linearly increased with the amount of indicator PCB ingested (P<0.001). Except for PCB 28, the slopes of the responses to soil and to oil could not be differentiated (P>0.1). RBA estimates did not differ from 1 for all indicator PCBs except for PCB 28, for which it was 0.58-0.59. Measurements performed on liver confirm these conclusions.

Glucose ingestion acutely lowers pulsatile LH and basal testosterone secretion in men

Chronic hyperglycemia inhibits the male gonadal axis. The present analyses test the hypothesis that acute glucose ingestion also suppresses LH and testosterone (T) secretion and blunts the LH-T dose-response function. The design comprised a prospectively randomized crossover comparison of LH and T secretion after glucose vs. water ingestion in a Clinical Translational Research Center. The participants were healthy men (n = 57) aged 19-78 yr with body mass index (BMI) of 20-39 kg/m(2). The main outcome measurements were deconvolution and LH-T dose-response analyses of 10-min data. LH-T responses were regressed on glucose, insulin, leptin, adiponectin, age, BMI, and CT-estimated abdominal visceral fat. During the first 120 min after glucose ingestion, for each unit decrease in LH concentrations, T concentrations decreased by 86 (27-144) ng/dl (r = 0.853, P < 0.001). Based upon deconvolution analysis, glucose compared with water ingestion reduced 1) basal (nonpulsatile; P < 0.001) and total (P < 0.001) T secretion without affecting pulsatile T output and 2) pulsatile (P = 0.043) but not basal LH secretion. By multivariate analysis, pulsatile LH secretion positively predicted basal T secretion after glucose ingestion (r = 0.374, P = 0.0042). In addition, the glucose-induced fall in pulsatile LH secretion was exacerbated by higher fasting insulin concentrations (P = 0.054) and attenuated by higher adiponectin levels (P = 0.0037). There were no detectable changes in the analytically estimated LH-T dose-response curves (P > 0.30). In conclusion, glucose ingestion suppresses pulsatile LH and basal T secretion acutely in healthy men. Suppression is influenced by age, glucose, adiponectin, and insulin concentrations.

Relationship between abdominal fat and bone mineral density in white and African American adults

Several studies have documented relationships between adipose tissue and bone mineral density (BMD); however, the degree to which there are racial differences in this relationship is not known. The purpose of this study was to examine the relationships between abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) and BMD among white and African American adults. The sample included 330 white women, 328 African American women, 307 white men, and 116 African American men 18-74 years of age. Dual-energy X-ray absorptiometry scans were used to measure BMD and computed tomography scans were used to measure abdominal VAT and SAT. Linear regression was used to assess the relationships between abdominal adiposity and BMD and to explore possible sex and race differences in the associations. In the total sample as well as in all sex-by-race groups, VAT and SAT were negatively related to BMD, after adjustment for lean body mass (LBM) and several covariates. The VAT model (including covariates) explained 33.3% of the variance in BMD and the SAT model (including covariates) explained 32.7% of the variance in BMD. Being African American, being male, and having high LBM were all associated with higher BMD. Race and sex interactions were not significant, indicating that the relationships were similar across race and sex groups. In conclusion, BMD was inversely related to abdominal VAT and SAT in white and African American adults after adjustment for LBM.

[Metabolic syndrome prevalence and clinical features in blood donors]

BACKGROUND

Metabolic syndrome (MS) including obesity, diabetes mellitus, hypertension, dyslipidemia, etc.. is a major cause of morbidity and mortality worldwide. It was reported that 15.9% of blood donors showed changes in fasting plasma glucose.

OBJECTIVE

To determine the prevalence of MS in a population of healthy donors in a secondary hospital.

MATERIAL AND METHODS

A cross-sectional study, included 726 healthy donors who attended the blood bank HGZ36. The SM was identified with at least 3 of 5 criteria of the NCEP ATPIII, we applied a structured questionnaire. We determined HDL cholesterol, triglycerides, glucose Abnormal Fasting (GAA), hypertension (SAH), body mass index (BMI), waist circumference (WC), hip circumference (NCC). Plan Analysis: prevalence, t student, Chi2.

RESULTS

Of the 726 donors, 85.1% were male, according to the ATPIII criteria, 54.8% (398) had a GAA, 63.2% (458) had hypertriglyceridemia, almost 17% (121) presented HDL hypocholesterolemia, 44.1% (320) were overweight by BMI, the prevalence of metabolic syndrome was 54.4%, in comparison by gender, men had a statistically significant difference compared to women, showing an OR = 2.27 (p = 0.0001, 95% CI 1.44-3.60).

CONCLUSIONS

MS is highly prevalent in this population, which involves implementing preventive measures, changes in lifestyles and identify risk factors to be free from diseases like diabetes, hypertension, obesity and MS itself.

MicroRNA expression in abdominal and gluteal adipose tissue is associated with mRNA expression levels and partly genetically driven

To understand how miRNAs contribute to the molecular phenotype of adipose tissues and related traits, we performed global miRNA expression profiling in subcutaneous abdominal and gluteal adipose tissue of 70 human subjects and characterised which miRNAs were differentially expressed between these tissues. We found that 12% of the miRNAs were significantly differentially expressed between abdominal and gluteal adipose tissue (FDR adjusted p<0.05) in the primary study, of which 59 replicated in a follow-up study of 40 additional subjects. Further, 14 miRNAs were found to be associated with metabolic syndrome case-control status in abdominal tissue and three of these replicated (primary study: FDR adjusted p<0.05, replication: p<0.05 and directionally consistent effect). Genome-wide genotyping was performed in the 70 subjects to enable miRNA expression quantitative trait loci (eQTL) analysis. Candidate miRNA eQTLs were followed-up in the additional 40 subjects and six significant, independent cis-located miRNA eQTLs (primary study: p<0.001; replication: p<0.05 and directionally consistent effect) were identified. Finally, global mRNA expression profiling was performed in both tissues to enable association analysis between miRNA and target mRNA expression levels. We find 22% miRNAs in abdominal and 9% miRNAs in gluteal adipose tissue with expression levels significantly associated with the expression of corresponding target mRNAs (FDR adjusted p<0.05). Taken together, our results indicate a clear difference in the miRNA molecular phenotypic profile of abdominal and gluteal adipose tissue, that the expressions of some miRNAs are influenced by cis-located genetic variants and that miRNAs are associated with expression levels of their predicted mRNA targets.

Lower extremity fat mass is associated with insulin resistance in overweight and obese individuals: the CARDIA study

Lower extremity fat mass (LEFM) has been shown to be favorably associated with glucose metabolism. However, it is not clear whether this relationship is similar across varying levels of obesity. We hypothesized that lower amounts of LEFM is associated with higher insulin resistance (IR) and this association may vary according to weight status. Participants with available measures were examined from the Coronary Artery Risk Development in Young Adults study (CARDIA), a multi-center longitudinal study of the etiology of atherosclerosis in black and white men and women aged 38-50 years old in 2005-2006 (n = 1,579). The homeostasis model assessment of IR (HOMA(IR)) was calculated to estimate IR, regional adiposity was measured using dual energy X-ray absorptiometry (DXA), and weight status was defined according to BMI categories. Obese and overweight participants exhibited higher IR, total fat mass (FM), trunk FM (TFM), and LEFM compared to normal weight participants. After controlling for age, height, race, study center, education, smoking, and cardiorespiratory fitness (CRF), greater LEFM was significantly associated with higher IR only in normal weight men and women. Further adjustment for TFM revealed that lower LEFM was significantly associated with higher IR in overweight and obese men and women and the positive association in normal weight individuals was attenuated. These results suggest that excess adiposity in the lower extremities may attenuate the metabolic risk observed at a given level of abdominal adiposity in overweight and obese individuals. Weight status presents additional complexity since the metabolic influence of adipose tissue may not be homogenous across anatomic regions or level of obesity.

Ethnic bias in anthropometric estimates of DXA abdominal fat: the TIGER study

BACKGROUND/INTRODUCTION

The purpose of this study was to examine the race/ethnicity bias of using waist circumference (WC) to estimate abdominal fat.

METHODS

A total of 771 females and 484 males (17-35 yr) were tested one to three times during a prescribed 30-wk aerobic exercise program. The race/ethnicity distribution for women was non-Hispanic white, 29%; Hispanic, 25%; African American (AA), 35%; Asian Indian, 3%; and Asian, 8%. The distribution for men was non-Hispanic white, 37%; Hispanic, 26%; AA, 22%; Asian Indian, 5%; and Asian, 10%. Abdominal fat (L1-L5) was estimated from whole-body scanning using dual-energy x-ray absorptiometry (DXA Abd-Fat).

RESULTS

DXA Abd-Fat varied by race/ethnicity after accounting for WC and height in both women and men. The increase in DXA Abd-Fat per increase in WC was lower in the Asian and Asian-Indian women than that in the other women. The increase in DXA Abd-Fat per increase in WC was higher in the AA men and lower in the Asian-Indian men than that in the other men. These differential race/ethnicity effects were most notable when WC exceeded ≍90 cm in the women and ≍100 cm in the men, values which are consistent with current definitions of abdominal obesity in the United States.

CONCLUSIONS

Prediction equations for abdominal fat using WC that do not account for race/ethnicity group provide biased estimates. These results may affect assessment of disease risk from abdominal obesity among racial/ethnic groups.

Positive correlation between tumor necrosis factor (TNF)-&#945; and cardiorespiratory fitness after six-months of regular aerobic exercise in Peruvian Amerindian women

BACKGROUND

Adipose tissue is a source of inflammatory cytokines which may influence insulin action.

AIM

To evaluate exercise effects on plasma (p)-levels of tumor necrosis factor (TNF)-α , and interleukin (IL)-6 in Peruvian Amerindian women.

MATERIAL AND METHODS

After five years of observation during which p-glucose deteriorated and weight increased, 44 Peruvian Amerindian women aged 20-59 years took part in a 6-month exercise program. Plasma TNF-α and IL-6 had been measured 5 years earlier, and were reassessed before and after exercise, using ELISA kits. Cardiorespiratory fitness was derived from the results of the twelve minutes' walk and expressed as maximum oxygen uptake (VO(2max)).

RESULTS

After the training program, estimated VO(2max) increased from 18.55 ± 3.79 to 20.91 ± 4.61 mL kg(-1) min(-1) (p < 0.01) and p-TNF-α increased from 3.2 ± 3.4 to 4.3 ± 6.6 pg/mL (p = 0.03). There were reductions in p-glucose from 5.19 ± 1.59 to 4.32 ± 1.62 mmol/L (p < 0.01) and in waist circumference (p=0.01). Weight, p-insulin, and IL-6 did not change. Levels of p-glucose and p-TNF-α observed after the training period were identical to values 5 years earlier. P-TNF-α was positively associated with estimated VO(2max), prior to (r = .414, p < 0.01) as well as after (r = .362, p < 0.05) exercise, independently of adiposity. P-IL-α was associated with waist circumference but not with estimated VO(2max).

CONCLUSIONS

P-TNF-a correlated with estimated VO(2max) independently of adiposity. Beneficial effects of exercise on p-glucose were observed in spite of an increase in p-TNF-α.

Exercise-induced myokines and their role in chronic diseases

Physical inactivity has recently been identified as a major and independent risk factor for the development of dementia and cognitive decline. In addition to the effect of exercise with regard to protection against neurodegenerative diseases, it is well-established that physical inactivity increases the risk of type 2 diabetes, cardiovascular diseases (CVD), colon cancer and postmenopausal breast cancer. These diseases constitute a network of related diseases, also called "the diseasome of physical inactivity". In this review, physical inactivity is given the central role as an independent and strong risk factor for accumulation of visceral fat and consequently the activation of a network of systemic inflammatory pathways, which promote development of neurodegeneration as well as insulin resistance, atherosclerosis, and tumour growth. The recent finding that muscles produce and release myokines provides a conceptual basis for understanding some of the molecular mechanisms underlying organ cross talk, including muscle-fat cross talk. Accumulating data suggest that contracting skeletal muscles release myokines, which may work in a hormone-like fashion, exerting specific endocrine effects on visceral fat or mediating direct anti-inflammatory effects. Other myokines work locally within the muscle via paracrine mechanisms, exerting their effects on signalling pathways involved in fat oxidation.

Influence of acute aerobic exercise on adiponectin oligomer concentrations in middle-aged abdominally obese men

Exercise intensity may induce changes in total adiponectin and adiponectin oligomer levels. However, the effects of acute aerobic exercise on total adiponectin and adiponectin oligomers in middle-aged abdominally obese men remain unknown. The purpose of this study was to investigate the influence of aerobic exercise intensity on changes in the concentrations of total adiponectin and adiponectin oligomers (high-molecular weight [HMW] and middle- plus low-molecular weight [MLMW] adiponectin), and the endocrine mechanisms involved in exercise-induced changes in adiponectin oligomer profiles in middle-aged abdominally obese men. Using a crossover design, 9 middle-aged abdominally obese men (age, 54.1 ± 2.4 years; body mass index, 27.9 ± 0.6 kg/m²) underwent 2 trials that consisted of 60 minutes of stationary cycle exercise at either moderate-intensity (ME) or high-intensity (HE) aerobic exercise (50% or 70% of peak oxygen uptake, respectively). Blood samples were collected to measure the concentrations of adiponectin oligomers, hormones (catecholamines, insulin, and growth hormone), metabolites (free fatty acid, glycerol, triglyceride, and glucose), and cytokines (interleukin-6 and tumor necrosis factor-α). After exercise, plasma catecholamine concentrations were higher during HE than during ME (P < .05). Total adiponectin concentration decreased at the end of HE (P < .05), but remained unchanged after ME. The HMW adiponectin concentration did not change at either intensity, whereas the MLMW concentration decreased at the end of HE (P < .05). The ratio of HMW to total adiponectin concentration increased significantly (P < .05), whereas the ratio of MLMW to total adiponectin concentration decreased significantly (P < .05), at the end of HE. The percentage changes in epinephrine concentration from baseline to the end of exercise were correlated with the percentage changes in total adiponectin concentration (r = -0.67, P < .05) and MLMW adiponectin concentration (r = -0.82, P < .05) from baseline to the end of HE. Our results indicate that the change in total adiponectin was mainly due to a change in MLMW adiponectin concentration during high-intensity exercise in middle-aged abdominally obese men. Epinephrine may partially regulate the decrease in total and MLMW adiponectin concentrations during high-intensity exercise.

Effects of diabetes family history and exercise training on the expression of adiponectin and leptin and their receptors

Daughters of diabetes patients have lower insulin sensitivity than women with no diabetes family history, but increase insulin sensitivity to a greater extent with exercise training. This study aimed to determine whether differences in circulating concentrations of adiponectin and leptin, and adipose tissue expression of their genes and receptors played a role. Women offspring of patients with type 2 diabetes mellitus (n = 34; age, 35.6 ± 7.0 years; body mass index, 28.1 ± 5.1 kg/m²) and matched controls with no diabetes family history (n = 36; age, 33.6 ± 6.1 years; body mass index, 27.3 ± 4.7 kg/m²) participated. Blood and abdominal subcutaneous adipose tissue samples were obtained at baseline and after a controlled 7-week endurance-type exercise intervention (sessions were performed at 65%-80% of maximum heart rate). At baseline, no significant differences were observed between groups in circulating leptin or adiponectin concentrations, or expression of their genes or receptors. In response to exercise, plasma leptin decreased more in offspring than controls (-32.2% vs -7.3%, P = .005 for interaction); and the long isoform of the leptin receptor messenger RNA (mRNA) increased significantly only in the offspring (+39.4%, P = .026 vs +7.7%, P = .892). Leptin mRNA decreased similarly in both groups (-24.7% vs -25.0%, P < .05 for both). Furthermore, changes in plasma leptin (r = -0.432, P < .001) and leptin mRNA (r = -0.298, P = .019) correlated significantly with changes in insulin sensitivity. Plasma adiponectin decreased similarly in both groups (-12.1% vs -15.2%, P < .01 for both), but no significant changes were observed in adiponectin-related gene expression. This work shows that exercise training has differing effects on leptin-related variables between women with and without a diabetes family history and suggests that these molecular differences may contribute to the differential effects of exercise training on insulin sensitivity between these 2 groups.

Do obese but metabolically normal women differ in intra-abdominal fat and physical activity levels from those with the expected metabolic abnormalities? A cross-sectional study

BACKGROUND

Obesity remains a major public health problem, associated with a cluster of metabolic abnormalities. However, individuals exist who are very obese but have normal metabolic parameters. The aim of this study was to determine to what extent differences in metabolic health in very obese women are explained by differences in body fat distribution, insulin resistance and level of physical activity.

METHODS

This was a cross-sectional pilot study of 39 obese women (age: 28-64 yrs, BMI: 31-67 kg/m2) recruited from community settings. Women were defined as 'metabolically normal' on the basis of blood glucose, lipids and blood pressure. Magnetic Resonance Imaging was used to determine body fat distribution. Detailed lifestyle and metabolic profiles of participants were obtained.

RESULTS

Women with a healthy metabolic profile had lower intra-abdominal fat volume (geometric mean 4.78 l [95% CIs 3.99-5.73] vs 6.96 l [5.82-8.32]) and less insulin resistance (HOMA 3.41 [2.62-4.44] vs 6.67 [5.02-8.86]) than those with an abnormality. The groups did not differ in abdominal subcutaneous fat volume (19.6 l [16.9-22.7] vs 20.6 [17.6-23.9]). A higher proportion of those with a healthy compared to a less healthy metabolic profile met current physical activity guidelines (70% [95% CIs 55.8-84.2] vs 25% [11.6-38.4]). Intra-abdominal fat, insulin resistance and physical activity make independent contributions to metabolic status in very obese women, but explain only around a third of the variance.

CONCLUSION

A sub-group of women exists who are metabolically normal despite being very obese. Differences in fat distribution, insulin resistance, and physical activity level are associated with metabolic differences in these women, but account only partially for these differences. Future work should focus on strategies to identify those obese individuals most at risk of the negative metabolic consequences of obesity and on identifying other factors that contribute to metabolic status in obese individuals.

Glucose metabolism and diet predict changes in adiposity and fat distribution in weight-reduced women

Among obesity-prone individuals, metabolic state may interact with diet in determining body composition. We tested the hypotheses that, among 103 weight-reduced women over 1 year, (i) insulin sensitivity would be positively associated with change in %fat; (ii) this association would be modulated by dietary glycemic load (GL); and (iii) changes in fat distribution would be related to indexes of glucose metabolism. Insulin sensitivity, glucose effectiveness, fasting and postchallenge insulin and glucose, and glucose tolerance were assessed during intravenous glucose tolerance test (IVGTT). Changes in %fat and fat distribution were examined using dual-energy X-ray absorptiometry and computed tomography. Dietary GL was assessed on 67 women using food records. On average, women showed a +5.3 +/- 3.0% change in %fat over 1 year, with the magnitude of this change being greater in relatively insulin sensitive women (+6.0 +/- 0.4%, mean +/- s.e.m.) than in relatively insulin resistant women (+4.4 +/- 0.4 kg; P < 0.05). Women who were relatively insulin sensitive and who consumed a higher GL diet showed a +6.8 +/- 0.7% change in %fat, which was greater than those who were less insulin sensitive, regardless of diet (P < 0.05), but did not differ from women who were relatively insulin sensitive and who consumed a lower GL diet (P = 0.105). Changes in intra-abdominal and deep subcutaneous abdominal fat were inversely associated with the postchallenge decline in serum glucose. In conclusion, greater insulin sensitivity may predispose to adiposity among weight reduced women, an effect that may be ameliorated by a lower GL diet. The potential association between indexes of glucose disposal and changes in fat distribution warrants further study.

Relation of the expression of transcriptional factor TFAP2B to that of adipokines in subcutaneous and omental adipose tissues

To determine the potential role of the transcriptional factor-activating enhancer-binding protein-2beta (TFAP2B) in the regulation of expression of adipokines, adiponectin, leptin, and interleukin-6 (IL-6) in vivo, we quantified the mRNA expression levels of these adipokines and TFAP2B in visceral (omental) and abdominal subcutaneous adipose tissues of 66 individuals with variable degree of adiposity and studied their correlations with BMI and their plasma concentrations. We found that BMI correlated negatively with plasma adiponectin levels and positively with those of leptin. Adiponection mRNA expression in subcutaneous fat correlated negatively with BMI, whereas leptin mRNA levels in the omentum correlated with plasma leptin levels and BMI. In contrast, IL-6 mRNA levels in subcutaneous and omental fat did not correlate with BMI. IL-6 mRNA levels in the omental fat correlated with plasma IL-6 levels. Whereas TFAP2B mRNA expression did not correlate with BMI, it correlated negatively with adiponectin expression in the subcutaneous adipose tissue. Furthermore, TFAP2B mRNA expression correlated negatively with leptin and positively with IL-6 expression in both subcutaneous and omental adipose tissues. These relationships are consistent with our in vitro observations and indicate that TFAP2B seems to regulate the expression of various adipokines in vivo.

Muscle mitochondrial oxidative phosphorylation activity, but not content, is altered with abdominal obesity in sedentary men: synergism with changes in insulin sensitivity

CONTEXT

Abdominal obesity is a major risk factor for muscle insulin resistance. Mitochondria may play a key role in this etiology.

OBJECTIVE

Changes in muscle mitochondrial content and function were examined according to abdominal obesity and insulin sensitivity in men.

STUDY DESIGN AND SETTING

The descriptive MitHyCal study was conducted on the general population of Clermont-Ferrand, France.

PARTICIPANTS

Forty-two healthy sedentary men (41.7 +/- 4.3 yr) were divided into four groups according to waist circumference: 87 cm or less (group 1, n = 10); 88-93 cm (group 2, n = 12); 94-101 cm (group 3, n = 10); and 102 cm or greater (group 4, n = 10).

INTERVENTION

Plasma metabolic check-up was performed, and insulin sensitivity index was calculated from glucose and insulin responses to a 3-h oral glucose tolerance test. Muscle biopsies were obtained to assess mitochondrial content, oxidative phosphorylation activity, and superoxide anion (reactive oxygen species) production.

MAIN OUTCOME MEASURES

Assessment of muscle mitochondrial content and function was planned before data collection began.

RESULTS

Abdominal obesity was negatively correlated to insulin sensitivity index (r = -0.39; P < 0.01), and only group 4 was insulin-resistant (P < 0.05). There were no between-group differences in muscle mitochondrial content and maximal activity of key oxidative enzymes. In contrast, muscle mitochondrial ADP-stimulated respiration rate was 24% higher in groups 2 and 3 compared to groups 1 and 4 (P < 0.05). Mitochondrial ATP and reactive oxygen species production rates were 27 and 48% lower in group 4 than in group 1 (P < 0.05).

CONCLUSION

Abdominal obesity is associated with alterations in intrinsic muscle mitochondrial function but not content. These adaptations mainly result in reduced mitochondrial ATP production rate in response to insulin resistance.

Critical role of the mesenteric depot versus other intra-abdominal adipose depots in the development of insulin resistance in young rats

OBJECTIVE

Age-associated insulin resistance may be caused by increased visceral adiposity and older animals appear to be more susceptible to obesity-related resistance than young animals. However, it is unclear to what extent the portally drained mesenteric fat depot influences this susceptibility.

RESEARCH DESIGN AND METHODS

Young high-fat-fed and old obese rats were subjected to 0, 2, 4, or 6 weeks of caloric restriction. Insulin sensitivity (S(I)) was assessed by hyperinsulinemic clamp and lean body mass (LBM) and total body fat were assessed by (18)O-water administration.

RESULTS

Six weeks of caloric restriction caused a similar reduction in body weight in young and old animals (P = 0.748) that was not due to reduced subcutaneous fat or LBM, but rather preferential loss of abdominal fat (P < 0.05). Most notably, mesenteric fat was reduced equivalently in young and old rats after 6 weeks of caloric restriction ( approximately decrease 53%; P = 0.537). Despite similar visceral fat loss, S(I) improved less in old ( increase 32.76 +/- 9.80%) than in young ( increase 82.91 +/- 12.66%) rats versus week 0. In addition, there was significantly more reversal of fat accumulation in the liver in young (% reduction: 89 +/- 2) versus old (64 +/- 5) rats (P < 0.0001). Furthermore, in young rats, S(I) changed much more rapidly for a given change in mesenteric fat versus other abdominal depots (slope = 0.53 vs. < or =0.27 kg/min/mg per % fat). CONCLUSIONS Improved S(I) during caloric restriction correlated with a preferential abdominal fat loss. This improvement was refractory in older animals, likely because of slower liberation of hepatic lipid. Furthermore, mesenteric fat was a better predictor of S(I) than other abdominal depots in young but not old rats. These results suggest a singular role for mesenteric fat to determine insulin resistance. This role may be related to delivery of lipid to liver, and associated accumulation of liver fat.

Serum leptin is associated with metabolic syndrome in obese and nonobese Korean populations

Leptin is mainly secreted from adipose tissue and is known to be associated with cardiovascular diseases. However, there are not many studies on the association between serum leptin and metabolic syndrome. The objective of this study was to determine the association between serum leptin and metabolic syndrome among the Korean adult population. The study population consisted of 3,272 Koreans (men: 1,915, women: 1,357) 30 to 84 years of age who had visited the Health Examination Center. Leptin levels were divided into quintiles and metabolic syndrome was defined by NCEP ATP III. The serum leptin levels increased as the number of components present for metabolic syndrome increased. Controlling for age, smoking, exercise, and LDL cholesterol, subjects with high leptin levels were more likely to have an elevated risk of metabolic syndrome than those with lower levels in both men and women. Subjects in the highest leptin quintile were found to have a higher risk of having metabolic syndrome than those in the lowest quintile (OR = 11.51 for men; OR = 4.65 for women). After further adjustment of the BMI, the risk of metabolic syndrome still increased slightly for men but not for women in increasing leptin categories. This association of leptin levels and metabolic syndrome did not change after stratification into obese and nonobese weight status. Serum leptin is associated with metabolic syndrome in Korean populations independent of body mass index. Thus, the reduction of circulating leptin may confer cardiovascular and metabolic protective effects regardless of weight status.

Socioeconomic position, stress, and cortisol in relation to waist circumference in African American and white women

OBJECTIVE

Abdominal fat deposition has been shown to be related to hypertension, dyslipidemia and diabetes. Studies have shown a correlation between cortisol (a stress hormone) and abdominal fat deposition. Low socioeconomic position (SEP) has also been shown to be related to abdominal fat deposition. It is hypothesized that chronic stress associated with low SEP leads to high cortisol levels which in turn lead to abdominal fat deposition. Previous research in this area has included mainly European subjects. The purpose of this study was to examine the evidence for the SEP-chronic stress-cortisol-abdominal fat hypothesis in a sample of African American and White American women.

DESIGN

Data from the Regional Assessment Health Surveillance Study (RAHSS), a survey and physical examination of a representative sample of African American and White adults residing in six counties in Georgia, were utilized. The study population included 111 African American and 119 White women. Abdominal fat deposition was measured by waist circumference (inches). Education and income were the measures of SEP. Other exposures examined included serum cortisol, self-reported daily stress level, cigarette smoking, marital status, and number of children. Associations were examined using multiple linear regression models adjusted for age and body mass index (BMI).

RESULTS

Among White women, less-educated women had a waist circumference 2.22 inches larger (P < .05) than more highly educated women. Among African American women, separated or divorced women (+2.29 in, P < .05) and widowed women (+3.13 in, P < .01) had larger waist circumferences than married women. No other factors were significantly associated with waist circumference.

CONCLUSIONS

The SEP-chronic stress abdominal fat accumulation hypothesis was only partially supported by the data. Different stressors and pathways may be important in producing abdominal fat accumulation in African American and White women.

Noninvasive evaluation of abdominal fat and liver changes following progressive weight loss in severely obese patients treated with laparoscopic gastric bypass

BACKGROUND

Obesity is a chronic complex disease, consequence of an unbalance between energy intake and expenditure and of the interaction between predisposing genotype and facilitating environmental factors. The aim of the study was to evaluate body composition, abdominal fat, and metabolic changes in a group of severely obese patients before and after laparoscopic gastric bypass (LGBP) at standardized (10% and 25%) total weight loss.

METHODS

Twenty-eight patients (14 M, 14 F; age 41.71 +/- 6.9 years; body mass index (BMI) 49.76 +/- 5.8 kg/m(2)) were treated with laparoscopic gastric bypass. All evaluations before surgery and after achieving ~10% and ~25% weight loss (WL). Body composition was assessed by bioimpedance analysis; resting metabolic rate (RMR) was measured by indirect calorimetry.

RESULTS

Body weight, BMI, and waist circumference significantly decreased at 10% and 25% WL. We observed a significant reduction of both RMR (2,492 +/- 388 at entry vs. 2,098 +/- 346.6 at 10% WL vs. 2,035 +/- 312 kcal per 24 h at 25% WL, p = 0.001 vs. baseline) as well as of RMR corrected for fat-free mass (FFM; 35.7 +/- 6.7 vs. 34.9 +/- 9.0 at 10% WL vs. 33.5 +/- 5.4 at 25% WL kilocalorie per kilogram FFM x 24 h, p = 0.041 vs. baseline). Body composition analysis showed a relative increase in FFM and a reduction of fat mass at 25% WL. A significant reduction in blood glucose, insulin, homeostasis model assessment index was observed. Ultrasonography showed a marked decrease in the signs of hepatic steatosis.

CONCLUSION

In conclusion, our study confirms that LGBP is a safe procedure in well-selected severely obese patients and has early favorable effects on both metabolic parameters and body composition. Longer-term observations are required for in-depth evaluation of body composition changes.

Effects of ginger root (Zingiber officinale) processed to different particle sizes on growth performance, antioxidant status, and serum metabolites of broiler chickens

A study using 144 one-day-old Arbor Acres broilers was conducted to assess the effects of dried ginger root (Zingiber officinale) that was processed to particle sizes of 300, 149, 74, 37, and 8.4 microm on growth performance, antioxidant status, and serum metabolites of broiler chickens. The birds were housed in 24 wire cages in an environmentally controlled room. Dietary treatments were no supplementation (control) and supplementation with ginger root processed to 5 particle sizes at the level of 5 g/kg of diet. Average daily gain, ADFI, and feed conversion rate of chicks of each cage were measured weekly. Blood samples from 8 broilers per treatment were obtained at d 21 and 42 of the experiment to determine antioxidant enzymatic activities and metabolites in the serum, and the birds were subsequently killed to determine carcass yield and abdominal fat content. All broilers had similar ADFI or feed conversion rate over the entire experimental period. However, broilers supplemented with ginger powder tended to have higher ADG and had greater (P=0.014) carcass yield compared with that of the control. Supplementation of ginger increased (P<0.001) activities of total superoxide dismutase and glutathione peroxidase but reduced (P<0.01) concentrations of malondialdehyde and cholesterol in serum of broilers at 21 and 42 d of age. Concentration of total protein in serum of ginger-supplemented broilers tended (P=0.092) to be higher at 21 d and was higher (P=0.002) at 42 d of age compared with that of control broilers. Reducing particle size of ginger powder linearly reduced (P<0.05) cholesterol (d 21) and linearly increased (P<0.05) glutathione peroxidase (d 21), total superoxide dismutase (d 42), and total protein (d 21 and 42). Supplementation of ginger at the level of 5 g/kg improved antioxidant status of broilers and the efficacy was enhanced as the particle size was reduced from 300 to 37 microm.

Body mass index is a major determinant of abdominal fat accumulation in pre-, peri- and post-menopausal women

OBJECTIVE

To investigate the role of menopause, body mass index (BMI) and aging on body fat distribution in women.

DESIGN

In this population-based cross-sectional study, 335 women (126 in pre-menopause, 75 in peri-menopause and 134 in post-menopause according to Stages of Reproductive Aging Workshop criteria) were evaluated for body mass composition and fat distribution by dual X-ray absorptiometry procedure. A sub-group of 79 women with similar age and BMI was extracted from the sample to examine the relative influence of BMI in body fat distribution.

RESULTS

ANCOVA analysis of total sample showed an age-independent increase of total fat mass (p < 0.001) and percentage on total weight (p < 0.001), arms fat mass (p < 0.01), legs fat mass percentage on total fat (p < 0.05) and trunk fat mass (p < 0.001) and percentage (p < 0.05) in peri- and post- with respect to pre-menopausal women. In the sub-sample including age and BMI matched women the difference of regional fat parameters among menopausal status was no more statistically significant.

CONCLUSION

BMI, and not age, is the main determinant of the increase of body fat mass (total and abdominal) observed during the menopausal transition.

Obesity in children and adolescents

CONTEXT

Although the prevalence rates of childhood obesity have seemingly been stable over the past few years, far too many children and adolescents are still obese. Childhood obesity, and its associated metabolic complications, is rapidly emerging as one of the greatest global challenges of the 21st century. About 110 million children are now classified as overweight or obese.

EVIDENCE ACQUISITION

In this review we first describe the most recent data on the prevalence, severity, and racial/ethnic differences in childhood obesity. Obesity is associated with significant health problems in the pediatric age group and is an important early risk factor for much of adult morbidity and mortality.

EVIDENCE SYNTHESIS

We review the metabolic complications associated with childhood obesity. Particular emphasis is given to the description of studies regarding the impact of varying degrees of obesity on the cardiometabolic risk factors in youth. We further describe studies in obese adolescents that have examined the importance of ectopic lipid deposition in the visceral abdominal depot and in insulin sensitive tissues in relation to the presence of insulin resistance. We end by describing studies that have examined beta-cell function in obese adolescents with normal glucose tolerance.

CONCLUSIONS

The growing number of obese children and adolescents worldwide is of great concern. Many obese children and adolescents already manifest some metabolic complications, and these children are at high risk for the development of early morbidity. Understanding the underlying pathogenesis of this peculiar phenotype is of critical importance.

Effect of ovarian suppression with gonadotropin-releasing hormone agonist on glucose disposal and insulin secretion

Several lines of evidence suggest that ovarian hormones influence glucose homeostasis, although their exact role in humans has not been clearly defined. In the present study, we sought to test the hypothesis that ovarian hormones regulate glucose homeostasis by examining the effect of pharmacologically induced ovarian hormone deficiency on glucose disposal and insulin secretion. Young, healthy women with regular menstrual patterns were studied during the follicular and luteal phases of their cycle at baseline and after 2 mo of treatment with gonadotropin-releasing hormone agonist (GnRHa; n = 7) or placebo (n = 6). Using hyperglycemic clamps, in combination with stable isotope-labeled (i.e., (13)C and (2)H) glucose tracers, we measured glucose disposal and insulin secretion. Additionally, we assessed body composition and regional fat distribution using radiologic imaging techniques as well as glucoregulatory hormones. Ovarian hormone suppression with GnRHa did not alter body composition, abdominal fat distribution, or thigh tissue composition. There was no effect of ovarian suppression on total, oxidative, or nonoxidative glucose disposal expressed relative to plasma insulin level. Similarly, no effect of ovarian hormone deficiency was observed on first- or second-phase insulin secretion or insulin clearance. Finally, ovarian hormone deficiency was associated with an increase in circulating adiponectin levels but no change in leptin concentration. Our findings suggest that a brief period of ovarian hormone deficiency in young, healthy, eugonadal women does not alter glucose disposal index or insulin secretion, supporting the conclusion that ovarian hormones play a minimal role in regulating glucose homeostasis. Our data do, however, support a role for ovarian hormones in the regulation of plasma adiponectin levels.

Race and gender differences in the relationships between anthropometrics and abdominal fat in youth

OBJECTIVE

We examined the influence of race and gender on abdominal adipose tissue (AT) distribution for a given anthropometric measure including waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height (W/Ht) in youth.

METHODS AND PROCEDURES

Subjects included healthy 62 black and 98 white youth. A single transverse image of the abdomen (L4-L5) was obtained using computed tomography.

RESULTS

For a given BMI, there was a significant (P<0.05) main effect of race and sex on the relationship between BMI and WC, such that boys and whites had a higher WC than girls and blacks. There was a significant (P<0.05) main effect and interaction effect of gender on the relationship between WC and visceral AT, such that boys had a higher visceral AT than girls, and the difference was magnified with increasing WC. For a given WC, black boys and girls had higher abdominal subcutaneous AT (SAT) than white peers, wherein the magnitude of the difference is increased with increasing WC. For a given W/Ht, black boys had significantly (P<0.05) lower visceral AT than white boys, but with no difference in girls. Black boys and girls had higher SAT than white peers, wherein the magnitude of the difference is increased with increasing W/Ht.

DISCUSSION

Our findings demonstrate a significant race and gender differential in the abdominal AT distribution for a given BMI, WC, WHR, and W/Ht. Future studies should take these differences into consideration when developing race- and gender-specific anthropometric cut-offs for obesity and obesity-related health risks in youth.

Preclinical vascular damage in white postmenopausal women: the relevance of osteoprotegerin

Osteoprotegerin (OPG) has recently been implicated in human atherogenesis. Abdominal obesity represents an established risk factor for the onset and development of atherosclerotic damage. The aim of the present study was to investigate the link between OPG and abdominal fat and the relationship to precocious features of atherosclerotic disease such as brachial flow-mediated vasodilation (FMV) and the intima-media thickening (IMT) in 195 white postmenopausal women (age range, 43-75 years). The study population was divided into 2 groups: group 1-waist circumference <80 cm and group 2-waist circumference > or = 80 cm. Group 2 had higher menopausal years, body mass index, low-density lipoprotein cholesterol, triglycerides, C-reactive protein, and carotid IMT. High-density lipoprotein cholesterol was higher in group 1. Afterward, these groups were divided on the basis of a cutoff value of OPG (6.85 pmol/L) that was the median of its distribution: patients with OPG < or = 6.85 pmol/L were OPG(-), and those with OPG >6.85 pmol/L were OPG(+). The OPG(+) subjects in both had lower brachial FMV and higher carotid IMT in comparison with OPG(-) subjects. At the multivariate regression analysis, waist circumference, high-density lipoprotein cholesterol, C-reactive protein, and OPG were predictors of carotid mean IMT (beta = 0.55, P = .001; beta = -0.14, P = .001; beta = 0.16, P = .001; and beta = 0.14, P = .05, respectively) and age, OPG, low-density lipoprotein cholesterol, and brachial diameter of brachial FMV (beta = -0.13, P = .05; beta = -0.25, P = .001; beta = -0.14, P = .024; and beta = 0.48, P = .001, respectively). The conclusions are as follows: first, OPG levels did not appear to be conditioned by a risk factor such as abdominal obesity; and second, OPG levels are mainly linked to the evidence of vascular damage. On this basis, we could speculate that OPG levels may be considered not a cardiovascular risk condition but a defense against atherosclerotic progression.

Serum sex hormone-binding globulin, a determinant of cardiometabolic disorders independent of abdominal obesity and insulin resistance in elderly men and women

Serum sex hormone-binding globulin (SHBG) is related to cardiometabolic disorders; but whether or not this relationship is purely secondary to hyperinsulinemia and/or obesity, which down-regulates SHBG, is unknown. The aim of the study was to investigate the association of SHBG and total testosterone with atherogenic dyslipidemias, metabolic syndrome (MS), and diabetes among predominantly elderly Turkish adults. After appropriate exclusions, 777 randomly selected male and female subjects with available measurements of both variables were eligible and were analyzed cross-sectionally, with diabetic subjects analyzed separately. Free testosterone was calculated. Metabolic syndrome was identified by the modified criteria of the Adult Treatment Panel III. Metabolic syndrome was identified in half the sample, which had a median age of 58 years. The odds of low SHBG concentrations (<45 nmol/L in men, <55 nmol/L in women) for the likelihood of 2 types of dyslipidemias, MS, and diabetes were examined by regression analyses in standard models including age, smoking status, presence of abdominal obesity, and insulin resistance (homeostasis model assessment of insulin resistance). In both sexes, low SHBG was associated independently with high triglyceride/low high-density lipoprotein dyslipidemia and with MS, at significant 2.2- to 4.5-fold odds ratios, independent of waist circumference or homeostasis model assessment of insulin resistance index. Low SHBG among women was additionally associated with the likelihood of hypertriglyceridemia with elevated apolipoprotein B and-at borderline significance-with that of diabetes, again when adjusted for the same confounders. In an elderly population with prevalent MS, low SHBG levels significantly associate with high triglyceride/low high-density lipoprotein dyslipidemia, MS, and, in women alone, diabetes and a dyslipidemia marking small dense low-density lipoprotein particles, all independent of abdominal obesity and insulin resistance. Low SHBG may be an important independent factor for cardiometabolic risk, particularly in women.

Insulin resistance, insulin response, and obesity as indicators of metabolic risk

CONTEXT

Insulin resistance (IR) and obesity, especially abdominal obesity, are regarded as central pathophysiological features of a cluster of cardiovascular risk factors (CVRFs), but their relative roles remain undefined. Moreover, the differential impact of IR viz. insulin response has not been evaluated.

OBJECTIVE

The objective of this study was to dissect out the impact of obesity, abdominal obesity, and IR/insulin response on CVRF.

DESIGN

This was a cross-sectional study.

SETTING

The study was conducted at 21 research centers in Europe.

SUBJECTS

The study included a cohort of 1308 nondiabetic subjects [718 women and 590 men, age 30-60 yr, body mass index (BMI) 17-44 kg.m(-2)].

MAIN OUTCOME MEASURES

We measured IR (by a standardized euglycemic insulin clamp), waist girth, insulin response to an oral glucose tolerance test, and major CVRF, and analyzed their associations by multivariate models and factor analysis.

RESULTS

BMI was positively related to all CVRFs. Waist circumference was related to higher blood pressure and serum triglycerides and lower high-density lipoprotein-cholesterol, IR to reduced glucose tolerance, higher free fatty acids, triglyceride and low-density lipoprotein-cholesterol, and lower high-density lipoprotein-cholesterol, and insulin response to higher heart rate, blood pressure and fasting glucose, and the same dyslipidemic profile as IR (P < or = 0.05 for all). By factor analysis, three main factors (related to IR, age, and fatness, respectively) appeared to underlie this pattern of associations. Each of BMI, waist girth, IR, and insulin response was independently associated with total CVRF load (all P < 0.001).

CONCLUSIONS

When IR, fat mass and distribution, and insulin response are measured simultaneously in a large cohort, no one factor stands out as the sole driving force of the CVRF cluster, each being associated with one or more physiological pathways according to known cause-effect relationships.

The increase in abdominal subcutaneous fat depot is an independent factor to determine the glycemic control after rosiglitazone treatment

OBJECTIVE

The goal was to investigate the interrelationships between the hypoglycemic effects of rosiglitazone and the changes in the regional adiposity of type 2 diabetic patients.

DESIGN AND METHODS

We added rosiglitazone (4 mg/day) to 173 diabetic patients (111 males and 62 females) already taking a stable dose of conventional antidiabetic medications except for thiazolidinediones. The abdominal fat distribution was assessed by ultrasonography at baseline and 12 weeks later. Using ultrasonographic images, the s.c. and visceral fat thickness (SFT and VFT respectively) were measured.

RESULTS

Rosiglitazone treatment for 3 months improved the glycemic control. However, the response to rosiglitazone was no more than 36.4%; the deterioration of the glycemic control was found in 16.8% of subjects. In addition, rosiglitazone treatment significantly increased the body fat mass, especially the s.c. fat. However that did not alter the visceral fat content. The percentage changes in fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) concentrations after treatment were inversely correlated with the increase in SFT (r=-0.327 and -0.353, P<0.001 respectively) and/or body weight (r=-0.316 and -0.327, P<0.001 respectively). Multiple regression analysis revealed that the improvement in the FPG after rosiglitazone treatment was correlated with the baseline FPG (P<0.001) and the change in the SFT (P=0.019), and the reduction in the HbA1c was related with the baseline FPG (P=0.003) and HbA1c (P<0.001) and the changes in the SFT (P=0.010) or VFT (P=0.013).

CONCLUSIONS

The increase in the s.c. fat depot after rosiglitazone treatment may be an independent factor that determines the hypoglycemic efficacy.

Why might South Asians be so susceptible to central obesity and its atherogenic consequences? The adipose tissue overflow hypothesis

The rates of coronary disease have accelerated dramatically amongst South Asians, driven to an important extent by the atherogenic dyslipidemia and type 2 diabetes that have become so common amongst them. These precursors of vascular disease appear at lower absolute amounts of adipose tissue in South Asians than in whites. In this paper, we set out a new hypothesis--the adipose tissue overflow hypothesis--to account for these findings. The adipose tissue mass within our bodies can be divided into three different compartments: superficial subcutaneous adipose tissue, deep subcutaneous adipose tissue and visceral adipose tissue. The superficial subcutaneous adipose tissue compartment is the primary compartment, is present throughout the body, and constitutes the vast majority of the adipose tissue in the lower limb. With energy excess, the secondary adipose tissue compartments--the deep subcutaneous (mainly upper body) and the visceral adipose tissue compartments--become more prominent. Superficial subcutaneous adipose tissue is relatively inert metabolically, whereas the other two compartments are characterized by higher transmembrane fatty acid flux rates and thus are more closely linked to dyslipidemia and dysglycemia. We hypothesize that the superficial subcutaneous adipose tissue compartment is larger in whites than in South Asians. If so, as obesity develops, South Asians exhaust the storage capacity of their superficial subcutaneous adipose tissue compartment before whites do and that is why they develop the metabolic complications of upper body obesity at lower absolute masses of adipose tissue than white people.

Body fat distribution reference standards in Spanish adolescents: the AVENA Study

OBJECTIVE

To present body fat patterning reference standards to identify children with a predominant distribution of body fat in the abdominal or truncal region of the body.

DESIGN

Cross-sectional study in a representative sample of Spanish adolescents aged 13-18 years.

SUBJECTS

A total of 2160 adolescents with a complete set of anthropometric measurements (1109 males and 1051 females).

MEASUREMENTS

Weight, height, body mass index, skinfold thickness (biceps, triceps, subscapular, suprailiac, thigh, calf) and waist and hip circumferences.

RESULTS

In the majority of the age groups, subscapular/triceps skinfolds ratio, trunk-to-total skinfolds percent (TTS%)and waist circumference values were significantly higher in males than in females; hip circumference was higher in females than in males, except at 15.5 years. In males, age showed a significant effect for all the body fat distribution indices; however, in females, the effect was only significant for triceps skinfold, waist and hip circumferences and waist-to-hip ratio. Smoothed age- and sex-specific triceps skinfold, subscapular skinfold, subscapular/triceps skinfolds ratio, TTS%, waist circumference and hip circumference, waist-to-hip and waist-to-height ratio percentile values for male and female adolescents have been established.

CONCLUSION

These reference data for waist circumference and the other fat patterning indices, together with data from other countries, will help to establish international central obesity criteria for adolescents. The presented percentile values will give the possibility to estimate the proportion of adolescents with high or low regional adiposity amounts.

Abdominal fat and risk of coronary heart disease in patients with peripheral arterial disease

OBJECTIVE

We investigated whether the presence of concomitant coronary heart disease (CHD) in patients with peripheral arterial disease (PAD) can be explained by intra-abdominal fat accumulation and compared different measures of adiposity as predictors of CHD in patients with PAD.

RESEARCH METHODS AND PROCEDURES

Data were collected from patients enrolled in the Second Manifestations of ARTerial disease (SMART) study, an ongoing prospective cohort study of patients with manifest vascular disease or vascular risk factors at the University Medical Centre Utrecht. The current analysis includes 315 patients, mean age 59 +/- 10 years, who had PAD with (n = 79) or without (n = 236) CHD. Parameters of adiposity were measured, and intra-abdominal fat and subcutaneous fat were measured ultrasonographically. Metabolic syndrome was defined according to Adult Treatment Panel III.

RESULTS

The prevalence of metabolic syndrome was higher among patients with CHD (63%) than among patients without CHD (48%). All parameters of adiposity indicated more fat in patients with CHD, except for subcutaneous fat. Waist circumference was associated with 64% higher prevalence of CHD (confidence interval, 20% to 123%) per 1 standard deviation increase in waist circumference after adjustment for age and sex. The odds ratio for waist circumference remained virtually the same after additional adjustment for the components of the metabolic syndrome and smoking.

DISCUSSION

An increased waist circumference, a crude measure of intra-abdominal fat, is associated with an increased risk of concomitant CHD in patients with PAD.

The metabolic syndrome and vascular disease in Asia

The metabolic syndrome is a constellation of vascular disease risk factors that includes hyperglycaemia, hypertension, and dyslipidaemia, which are largely mediated by accumulating fat depots, particularly when centrally deposited. Increasing adiposity promotes insulin resistance, low grade inflammation and endothelial dysfunction, which promote the development of atherogenic vascular disease. Increases in percentage body fat result from a number of parameters, including ageing, and changes in lifestyle factors that promote a metabolic imbalance, such as decreasing physical activity and adverse dietary patterns. As Asian populations continue to modernize, levels of physical activity are declining as home and workplace jobs become more automated and sedentary and transportation more readily available. Similarly, dietary changes are introduced, with healthy traditional plant-based diets being replaced by cheaper calorie dense high fat foods. These changes are resulting in rapid increases in the prevalence of obesity throughout Asia, and the subsequent development of the metabolic syndrome. To minimise further development of the obesity pandemic and subsequent vascular disease, innovative population-based preventative lifestyle and therapeutic strategies interventions need to be introduced.