High prevalence of the metabolic syndrome in Iranian adolescents

Objective : No evidence exists regarding the prevalence of the metabolic syndrome in adolescents in Middle Eastern countries. We aimed to evaluate the prevalence of the metabolic syndrome in a representative sample of Iranian adolescents. Research Methods and Procedures : Anthropometry, biochemical measurements, and blood pressure were assessed in a population‐based cross‐sectional study of 3036 Iranian adolescents (1413 boys and 1623 girls) 10 to 19 years of age. Metabolic syndrome was defined according to modified Adult Treatment Panel III definition. Overweight (≥95th percentile) and at risk for overweight (≥85th to <95th percentile) was defined based on the standardized percentile curves of BMI suggested for Iranian adolescents. Results : The prevalence of the metabolic syndrome was 10.1% (95% confidence interval: 9.0 to 11.1) among Iranian adolescents (boys: 10.3%, 8.6 to 11.8; girls: 9.9%, 8.4 to 11.3). Overall, low serum high‐density lipoprotein‐cholesterol and high serum triglycerides were the most common components of the metabolic syndrome (42.8% and 37.5%, respectively). Overweight subjects had the highest proportion of metabolic syndrome compared with those at risk for overweight and those with normal weight (boys: 41.1% vs. 11.4% and 3.0%, respectively, p < 0.01; girls: 43% vs. 15.2% and 5.0%, respectively, p < 0.01). Discussion : This study provides evidence showing a high prevalence of the metabolic syndrome in Iranian adolescents, particularly among overweight adolescents.     

In vivo body composition in autochthonous and conventional pig breeding groups by dual-energy X-ray absorptiometry and magnetic resonance imaging under special consideration of Cerdo Ibérico

The improvement of carcass quality is one of the main breeding goals in pig production. To select appropriate breeding animals, it is of major concern to exactly and reliably analyze the body composition in vivo. Therefore, the objective of the study was to examine whether the combination of dual-energy X-ray absorptiometry (DXA) and magnetic resonance imaging (MRI) offers the opportunity to reliably analyze quantitative and qualitative body composition characteristics of different pig breeding groups in vivo. In this study, a total of 77 pigs were studied by DXA and MRI at an average age of 154 days. The pigs originated from different autochthonous or conventional breeds or crossbreeds and were grouped into six breed types: Cerdo Ibérico (Ib); Duroc × Ib (Du_Ib); White Sow Lines (WSL, including German Landrace and German Large White); Hampshire/Pietrain (Pi_Ha, including Hampshire, Pietrain × Hampshire (PiHa) and Pietrain × PiHa); Pietrain/Duroc (Pi_Du, including Pietrain × Duroc (PiDu) and Pietrain × PiDu); crossbred WSL (PiDu_WSL, including Pietrain × WSL and PiDu × WSL). A whole-body scan was performed by DXA with a GE Lunar DPX-IQ in order to measure the amount and percentage of fat tissue (FM; %FM), lean tissue (LM; %LM) and bone mineral, whereas a Siemens Magnetom Open with a large body coil was used for MRI in the thorax region between 13th and 14th vertebrae in order to measure the area of the loin (LA) and the above back fat area (FA) of both body sides. A GLM procedure using SAS 9.2 was used to analyze the data. As expected, the native breed Ib followed by Du_Ib crossbreeds showed the highest %FM (27.2%, 25.0%) combined with the smallest LA (46.2 cm², 73.6 cm²), whereas Ib had the lowest BW at an average age of 154 days. Pigs with Pi_Ha origin presented the least %FM (12.4%) and largest LA (99.5 cm²). The WSL and PiDu_WSL showed an intermediate body composition. Therefore, it could be concluded that DXA and MRI and especially their combination are very suitable methods to reliably identify differences in body composition and carcass traits among different pig lines in vivo.     

Measurement of body composition in response to a short period of overfeeding

Background

Obesity and overweight are increasing in prevalence in developed countries as a result of changing dietary habits and a lack of physical activity. The purpose of the present study was to evaluate the changes in body composition during short-term overfeeding using the three-component model, which is composed of fat mass (FM), total body water (TBW), and fat-free dry solids (FFDS).

Methods

Ten healthy men completed 3 days of overfeeding during which they consumed 1,500 kcal/day more energy than consumed in their normal diets. Body composition was evaluated at three time points: the day before and after their normal diets and the day after the 3-day overfeeding diet.

Results

Before and after their normal diets, there were no significant differences in body weight and composition, but after 3 days of overfeeding, body weight, TBW, and FFDS increased 0.7, 0.7, and 0.2 kg, respectively (P <0.0001). There was no significant difference in FM between the normal and overfeeding diets.

Conclusion

This study suggests that TBW gain contributes to weight gain following a short-term overfeeding.     

Waist circumference correlates with metabolic syndrome indicators better than percentage fat

Objective : Percent fat is often considered the reference for establishing the magnitude of adipose tissue accumulation and the risk of excess adiposity. However, the increasing recognition of a strong link between central adiposity and metabolic disturbances led us to test whether waist circumference (WC) is more highly correlated with metabolic syndrome components than percent fat and other related anthropometric measures such as BMI. Research Methods and Procedures : BMI, WC, and percent fat, measured by DXA, were evaluated in 1010 healthy white and African‐American men and women [age, 48.3 ± 17.2 (standard deviation) years; BMI, 27.0 ± 5.3 kg/m²]. The associations of BMI, WC, and percent fat with age and laboratory‐adjusted health risk indicators (i.e., serum glucose, insulin, triglycerides, high‐density lipoprotein cholesterol, blood pressure) in each sex and ethnicity group were examined. Results : For 18 of 24 comparisons, the age‐ and laboratory‐adjusted correlations were lowest for percent fat and in 16 of 24 comparisons were highest for WC. Fifteen of the between‐method differences reached statistical significance. With health risk indicator as the dependent variable and anthropometric measures as the independent variable, the contribution of percent fat to the WC regression model was not statistically significant; in contrast, adding WC to the percent fat regression model did make a significant independent contribution for most health risk indicators. Discussion : WC had the strongest associations with health risk indicators, followed by BMI. Although percent fat is a useful measure of overall adiposity, health risks are best represented by the simply measured WC.     

The metabolic rate of roach in relation to body size and temperature

Standard and routine metabolic rates of roach Rutilus rutilus for a wide size and temperature range (3–200 g, 5–23° C) were analysed by automated, computerized intermittent flow respirometry. The mass exponent b ranged from 0·68 to 0·82 for standard metabolism, and from 0·65 to 0·92 for routine metabolism depending on the experimental temperature. For routine metabolism b was lowest at 10° C. At both decreasing and increasing temperatures, b increased significantly. Roach were exponentially temperature-dependent for both metabolic levels. For roach <20 g, however, an asymptotic relationship was observed between temperature and routine metabolic rate. The 'flattening of the curve' in the latter case may be explained by reduced spontaneous activities at the lower threshold of the preferred temperature range.     

Age-related changes in the metabolism and body composition of three dog breeds and their relationship to life expectancy

We measured body composition and resting metabolic rates (RMR) of three dog breeds (Papillons, mean body mass 3.0 kg (n = 35), Labrador retrievers, mean body mass 29.8 kg (n = 35) and Great Danes, mean body mass 62.8 kg (n = 35)) that varied between 0.6 and 14.3 years of age. In Papillons, lean body mass (LBM) increased with age but fat mass (FBM) was constant; in Labradors, both LBM and FBM were constant with age, and in Great Danes, FBM increased with age but LBM was constant. FBM averaged 14.8% and 15.7% of body mass in Papillons and Labradors, respectively. Great Danes were leaner and averaged only 10.5% FBM. Pooling the data for all individuals, the RMR was significantly and positively associated with LBM and FBM and negatively associated with age. Once these factors had been taken into account there was still a significant breed effect on RMR, which was significantly lower in Labradors than in the other two breeds. Using the predictive multiple regression equation for RMR and the temporal trends in body composition, we modelled the expenditure of energy (at rest) over the first 8 years of life, and over the entire lifespan for each breed. Over the first 8 years of life the average expenditure of energy per kg LBM were 0.985, 0.675 and 0.662 GJ for Papillons, Labradors and Great Danes, respectively. This energy expenditure was almost 60% greater for the smallest compared with the largest breed. On average, however, the life expectancy for the smallest breed was a further 6 years (i.e. 14 years in total), whereas for the largest breed it was only another 6 months (i.e. 8.5 years in total). Total lifetime expenditure of energy at rest per kg LBM averaged 1.584, 0.918 and 0.691 GJ for Papillons, Labradors and Great Danes, respectively. In Labradors, total daily energy expenditure, measured by the doubly labelled water method in eight animals, was only 16% greater than the observed RMR. High energy expenditure in dogs appears positively linked to increased life expectancy, contrary to the finding across mammal species and within exotherms, yet resembling observations in other intra-specific studies. These contrasting correlations suggest that metabolism is affecting life expectancy in different ways at these different levels of enquiry.     

环境和遗传因素与慢性代谢性疾病的人群研究

几十年来我国居民经历了快速的营养转型,与不健康的膳食和生活方式相关的＂致肥环境＂,以及遗传倾向是导致我国慢性代谢性疾病如代谢综合征和2型糖尿病快速流行的主要推手。然而,我国目前非常缺乏针对导致慢性代谢性疾病的主要遗传和环境危险因素而开展的系统研究。在过去若干年中,通过开展基于社区人群的流行病学研究,本课题组发现了多个与代谢性疾病相关的基因变异、环境因素和生物标记物。与此同时,通过对代谢综合征或2型糖尿病患者进行的营养干预,发现添加亚麻子或其衍生物木酚素、核桃,以及用糙米替代白米能不同程度地改善代谢综合征或血糖控制。总之,所有努力旨在增进对导致中国人代谢性疾病高易感性相关的病因和机制的理解,同时也希望为疾病的预测和预防提供新的思路和线索。     

IgA antibodies to Chlamydia trachomatis and metabolic syndrome

Chlamydia pneumoniae may trigger atherogenesis. Chlamydia trachomatis (CT) can also induce endothelial activation. However, its role in metabolic syndrome (METS), a proatherogenic entity, has remained unexplored. In this study the frequencies of IgA and IgG anti-CT antibodies were evaluated by immunoenzymatic assay in METS patients and healthy controls. The survey included 238 individuals (148 with METS). The mean age was 59.7 years. IgA anti-CT antibodies were found significantly more frequently in METS patients (16.9%) than in controls (5.6%) (P= 0.015). The role of such IgA response in METS should be further investigated.     

Bioelectrical impedance vs. four-compartment model to assess body fat change in overweight adults

Objective: The Tanita TBF‐305 body fat analyzer is marketed for home and clinical use and is based on the principles of leg‐to‐leg bioelectrical impedance analysis (BIA). Few studies have investigated the ability of leg‐to‐leg BIA to detect change in percentage fat mass (%FM) over time. Our objective was to determine the ability of leg‐to‐leg BIA vs. the four‐compartment (4C) model to detect small changes in %FM in overweight adults. Research Methods and Procedures: Thirty‐eight overweight adults (BMI, 25.0 to 29.9 kg/m²; age, 18 to 44 years; 31 women) participated in a 6‐month, randomized, double‐blind, placebo‐controlled study of a nutritional supplement. Body composition was measured at 0 and 6 months using the Tanita TBF‐305 body fat analyzer [using equations derived by the manufacturer (%FM_T‐Man) and by Jebb et al. (%FM_T‐Jebb)] and the 4C model (%FM_4C). Results: Subjects in the experimental group lost 0.9%FM_4C (p = 0.03), a loss that did not reach significance using leg‐to‐leg BIA (0.6%FM_T‐Man, p = 0.151; 0.6%FM_T‐Jebb, p = 0.144). We observed large standard deviations (SDs) in the mean difference in %FM between the 4C model and the Tanita_Manufacturer (2.5%) and Tanita_Jebb (2.2%). Ten subjects fell outside ±1 SD of the mean differences at 0 and 6 months; those individuals were younger and shorter than those within ±1 SD. Discussion: Leg‐to‐leg BIA performed reasonably well in predicting decreases in %FM in this group of overweight adults but resulted in wide SDs vs. %FM_4C in individuals. Cross‐sectional determinations of %FM of overweight individuals using leg‐to‐leg BIA should be interpreted with caution.     

Age variations in the relation of body mass indices to estimates of body fat and muscle mass

In some chronic disease studies, distinctions have been made regarding the importance of body mass index (BMI) as a risk factor in younger versus older men and women. In order to determine the significance of these differences in BMI-disease associations, we determined the extent of age-dependent variations in the relation of BMIs to body composition in large probability samples of U.S. men and women from the First and Second U.S. National Health and Nutrition Examination Surveys (NHANES I and II). BMIs are more highly correlated with estimates of body fat in younger than in older men and women, and with muscle mass in older than in younger adults. Caution should be exercised in interpreting the significance of BMI as a risk factor for chronic disease, particularly in comparison of age groups.     

Prevalence of the Metabolic Syndrome in a Bulgarian Female Population Referred for Bone Density Testing

Objective: To investigate the prevalence of the metabolic syndrome in Bulgarian women referred for bone density screening. Research Methods and Procedures: This was a cross‐sectional clinical study. Subjects were 444 consecutive 30‐ to 75‐year‐old Bulgarian women recruited from the outpatients referred for bone density testing (mean age, 52.67 ± 15.19 years; mean BMI, 26.10 ± 5.71 kg/m²). Height (centimeters), weight (kilograms), and blood pressure were measured. BMI and waist‐to‐hip ratio were calculated. Fasting plasma glucose, blood lipids, and immunoreactive insulinemia (Bayer Corp.‐Diagnostics Div., Tarrytown, NY) were determined. Body composition was analyzed by bioimpedance on a leg‐to‐leg analyser (Tanita TBF‐215; Tanita Corporation, Tokyo, Japan). Results: Of all women, 56.76% had a BMI > 25 kg/m², 45.95% had a waist circumference > 88 cm, and 64.64% had a waist‐to‐hip ratio > 0.8; 59.90% had hypertension; 4.05% had fasting plasma glucose > 7.0 mM, and 42.79% had fasting morning immunoreactive insulinemia = 16 UI/liter; 23.65% had hypercholesterolemia; and 26.35% had hypertriglyceridemia. The prevalence of the metabolic syndrome in this sample, as defined by the National Cholesterol and Education Program‐Adult Treatment Panel III, was 34.91%, and by the modified World Health Organization definition was 37.16%. Discussion: We concluded that Bulgarian women 30 to 75 years old referred for bone density testing have a high prevalence of the metabolic syndrome. Therefore, large‐scale prevention programs are needed in this field.     

The link between the metabolic syndrome and cancer

Since the incidence of the metabolic syndrome is on the rise in the western world, its coherence to cancer is becoming more apparent. In this review we discuss the different potential factors involved in the increase of cancer in the metabolic syndrome including obesity, dyslipidemia and Type 2 Diabetes Mellitus (T2DM) as well as inflammation and hypoxia. We especially focus on the insulin and IGF systems with their intracellular signaling cascades mediated by different receptor subtypes, and suggest that they may play major roles in this process. Understanding the mechanisms involved will be helpful in developing potential therapeutics.     

Modelling hand skin temperature in relation to body composition

Skin temperature is a challenging parameter to predict due to the complex interaction of physical and physiological variations. Previous studies concerning the correlation of regional physiological characteristics and body composition showed that obese people have higher hand skin temperature compared to the normal weight people. To predict hand skin temperature in a different environment, a two-node hand thermophysiological model was developed and validated with published experimental data. In addition, a sensitivity analysis was performed which showed that the variations in skin blood flow and blood temperature are most influential on hand skin temperature. The hand model was applied to simulate the hand skin temperature of the obese and normal weight subgroup in different ambient conditions. Higher skin blood flow and blood temperature were used in the simulation of obese people. The results showed a good agreement with experimental data from the literature, with the maximum difference of 0.31 °C. If the difference between blood flow and blood temperature of obese and normal weight people was not taken into account, the hand skin temperature of obese people was predicted with an average deviation of 1.42 °C. In conclusion, when modelling hand skin temperatures, it should be considered that regional skin temperature distribution differs in obese and normal weight people.     

白藜芦醇对成年期追赶生长大鼠体成分的影响及机制

目的:观察白藜芦醇对成年期追赶生长大鼠体成分的影响及可能机制。方法:8周龄雄性 SD 大鼠分为6组(共2个时间点),即4周时间点3组:正常饮食4周 (NC4)组、热卡限制4周(R4)组,热卡限制同时白藜芦醇治疗(R4E)组;12周时间点3组:正常饮食12周(NC12)组,追赶生长(CUG)组,追赶生长白藜芦醇治疗(CUGE)组。每组含6只大鼠,白藜芦醇用生理盐水配制成一定浓度悬浊液,按100 mg/(kg·d)剂量予实验动物灌胃治疗。实验第4周、12周检测体重、躯干和全身的肌肉及脂肪含量、躯干与全身脂肪比例,实验第12周检测骨骼肌与附睾脂肪组织SIRT1的表达,附睾脂肪组织PPARγ的表达。结果:与NC12组相比,CUG组躯干及全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显升高(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达显著降低(P＜0.05或P＜0.01);与CUG组相比,经白藜芦醇干预后的CUGE组全身的脂肪含量、躯干与全身脂肪比例、附睾脂肪组织PPARγ的表达均明显降低(P＜0.05),肌肉含量、骨骼肌与附睾脂肪组织SIRT1的表达较CUG组显著提高(P＜0.05)。结论:白藜芦醇降低成年期追赶生长大鼠体脂含量,增加肌肉含量,改善腹部脂肪堆积,其机制可能与增加骨骼肌及内脏脂肪组织SIRT1表达,抑制内脏脂肪PPARγ的表达有关。     

Familial aggregation of metabolic syndrome and its components in a large Chinese population

Objective: To investigate the familial aggregation of metabolic syndrome (MetS) and its components in the Chinese. Methods and Procedures: A total of 17,954 subjects from 5,224 families with multiple siblings aged 25–64 years old (mean age 45.8 years, 51.6% male) were enrolled from a rural area of Anhui Province of China during 2004–2005. Anthropometric measurement, body composition, blood pressure, plasma lipids, and fasting glucose and insulin, as well as a questionnaire interview, were obtained from each participant. Results: Significant correlations among siblings were observed in all the traits examined, including BMI, waist circumference, total body and abdominal fat percentage, fasting plasma glucose (FPG) and insulin, insulin resistance index of homeostatic model assessment (HOMA‐IR), total cholesterol, triglyceride, high‐density lipoprotein cholesterol (HDL‐C), low‐density lipoprotein cholesterol, and blood pressure, after adjustment for age, gender and some other covariates. The correlation coefficients varied from 0.18 for FPG to 0.42 for HDL‐C. In stratified analyses, we found siblings with a smaller age gap among them had higher intraclass correlation coefficients (ICCs) for most of the above phenotypes than those with a greater age difference, and the correlation of systolic blood pressure (SBP) was stronger in male siblings than that in female. If the eldest sibling is affected by MetS or any of its components, younger siblings bear a twofold to threefold higher risk for developing MetS or any of its components than those with a healthy eldest sibling. Discussion: Our study demonstrated a significant familial resemblance as regards MetS and its components among the Chinese. Further studies are warranted to investigate specific genetic and environmental factors related to MetS in this population.     

人体成分研究概览

近年来,我国体成分的研究取得了可喜的进步。为了庆贺吴新智院士九十华诞并回应学者们在中国解剖学会人类学专业委员会(呼和浩特)召开的体成分会议上提出的问题,推动我国体成分的研究,本文搜集了国人1985年以来在国内外发表的730篇体成分方面的研究文献,内容涵盖研究方法及其有效性、体成分的应用、人的体成分的差异以及理论等方面并与当前国际最新研究进展进行对照分析,找出我们的差距并提出今后的建议。     

Cinnamon improves insulin sensitivity and alters the body composition in an animal model of the metabolic syndrome

Polyphenols from cinnamon (CN) have been described recently as insulin sensitizers and antioxidants but their effects on the glucose/insulin system in vivo have not been totally investigated. The aim of this study was to determine the effects of CN on insulin resistance and body composition, using an animal model of the metabolic syndrome, the high fat/high fructose (HF/HF) fed rat. Four groups of 22 male Wistar rats were fed for 12 weeks with:

(i)

(HF/HF) diet to induce insulin resistance,

(ii)

HF/HF diet containing 20 g cinnamon/kg of diet (HF/HF + CN),

(iii)

Control diet (C) and

(iv)

Control diet containing 20 g cinnamon/kg of diet (C + CN).

Data from hyperinsulinemic euglycemic clamps showed a significant decrease of the glucose infusion rates in rats fed the HF/HF diet. Addition of cinnamon to the HF/HF diet increased the glucose infusion rates to those of the control rats. The HF/HF diet induced a reduction in pancreas weight which was prevented in HF/HF + CN group (p < 0.01). Mesenteric white fat accumulation was observed in HF/HF rats vs. control rats (p < 0.01). This deleterious effect was alleviated when cinnamon was added to the diet. In summary, these results suggest that in animals fed a high fat/high fructose diet to induce insulin resistance, CN alters body composition in association with improved insulin sensitivity.     

Effects of muscular and aqua aerobic combined exercise on metabolic indices in elderly women with metabolic syndrome

The purpose of this study was to investigate the effects of muscle strengthening exercise using elastic thera-band and aquatic aerobic combined exercise on metabolic syndrome index in elderly with metabolic syndrome. Fifty-four were assigned to muscle strengthening exercise group (n = 19), aquatic aerobic exercise group (n = 19), and combined exercise group (n = 16). The muscle strength exercise, aquatic aerobic exercise and combined exercise were provided three times a week for 12 weeks. Metabolic syndrome indices[Fasting blood glucose, triglyceride, high density lipoprotein cholesterol (HDL-C), systolic blood pressure, diastolic blood pressure and waist circumference] were measured before and after the program. One-way ANOVA, paired t-test and two-way repeated ANOVA were used with the SPSS program for data analysis. There was a significant difference in triglyceride (p < .001), HDL-C (p = .010) and waist circumference (p = .016). Triglyceride and waist circumference was significantly decreased in combined group than muscle strength exercise group and aquatic exercise group. HDL-C was significantly increased in combined group than muscle strength exercise group. The results indicate that combined exercise was more effective in the improvement of dyslipidemia and abdominal obesity.