Regional abdominal fat distribution in lean and obese Thai type 2 diabetic women: relationships with insulin sensitivity and cardiovascular risk factors

Which adiposity index is best? Comparison of five indicators and their ability to identify type 2 diabetes risk in a population study

AIMS

We compared ability of five adiposity indicators [body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR), waist-by-height0.5 (WHT.5R), and a body shape index (ABSI)] to identify current diabetes and their prospective associations with diabetes.

METHODS

Baseline data were from 7,979 participants of UK Whitehall II study, of whom 7,488 diabetes-free participants were followed-up (median = 16.0 years) for incident diabetes (n = 940). According to five indices' cut-points, participants were separately classified into low-value groups and high-value groups. We cross-sectionally investigated ability of the indicators to identify existing diabetes by receiver operating characteristic curve analysis, and explored prospective associations between elevated indices and diabetes using Cox regression analysis.

RESULTS

Waist-based indicators were superior to BMI in identifying diabetes. High WHtR (≥0.5) demonstrated the highest multivariable-adjusted HR [2.64 (95 % CI 2.29, 3.03)]. Across all indicators, associations between elevated indicators and diabetes were stronger in younger participants. In combined analyses, "low BMI but high WHtR" had higher risk for diabetes [2.20 (95 % CI 1.65, 2.95)] than "high BMI but low WHtR" [1.34 (95 % CI 1.05, 1.70)].

CONCLUSION

Waist-based indicators are more strongly associated with diabetes than BMI. WHtR, an easy-to-calculate, waist-based index with a sex- and race-independent cut-point, may be useful for diabetes prevention.

Effect of Psyllium husk fiber and lifestyle modification on human body insulin resistance

Insulin resistance is a metabolic disorder that is increasing worldwide and is associated with some of the most common diseases affecting modern societies including diabetes, hypertension, obesity, and coronary heart disease. Changes in diet and physical activity have a profound effect on lowering the risk and cost of managing insulin resistance compared to the pharmacological approach. An interventional study of 16 weeks explored the effect of Psyllium husk fiber in combination with lifestyle modification on insulin resistance among the centrally obese school teachers of district Malakand Khyber Pakhtunkhwa. One Hundred twenty school teachers with central obesity, aged 40-60 years, with no chronic disease history were divided into four subgroups (n = 30) with equal gender bifurcation; a control group, lifestyle modification (LSM) group, psyllium husk fiber (PSH) group, and the combined intervention of LSM & PSH group. Fasting serum was collected to analyze fasting blood glucose, and insulin resistance by using the HOMA-IR method at baseline and post-intervention. A significant effect of the intervention was observed on fasting blood glucose. The combined group of LSM&PSH showed the highest mean change of -7.5 ± 2.6 mg/dl (-9%), followed by the PSH group with a mean change of -6.3 ± 2.1 mg/dl, (-7%). Likewise a significant effect (P < 0.05) on HOMA-IR was observed in the combined group of LSM&PSH with a mean of 1.02 ± 0.14 molar units (-58%), followed by the PSH group with a mean of 1.55 ± 0.14 molar units (-33%). The current study was carried out to assess the effect of regular consumption of Psyllium husk fiber in combination with lifestyle modification on insulin resistance and fasting blood glucose.

The impact of ethnicity and intra-pancreatic fat on the postprandial metabolome response to whey protein in overweight Asian Chinese and European Caucasian women with prediabetes

The "Thin on the Outside Fat on the Inside" TOFI_Asia study found Asian Chinese to be more susceptible to Type 2 Diabetes (T2D) compared to European Caucasians matched for gender and body mass index (BMI). This was influenced by degree of visceral adipose deposition and ectopic fat accumulation in key organs, including liver and pancreas, leading to altered fasting plasma glucose, insulin resistance, and differences in plasma lipid and metabolite profiles. It remains unclear how intra-pancreatic fat deposition (IPFD) impacts TOFI phenotype-related T2D risk factors associated with Asian Chinese. Cow's milk whey protein isolate (WPI) is an insulin secretagogue which can suppress hyperglycemia in prediabetes. In this dietary intervention, we used untargeted metabolomics to characterize the postprandial WPI response in 24 overweight women with prediabetes. Participants were classified by ethnicity (Asian Chinese, n=12; European Caucasian, n=12) and IPFD (low IPFD < 4.66%, n=10; high IPFD ≥ 4.66%, n=10). Using a cross-over design participants were randomized to consume three WPI beverages on separate occasions; 0 g (water control), 12.5 g (low protein, LP) and 50 g (high protein, HP), consumed when fasted. An exclusion pipeline for isolating metabolites with temporal (T_0-240mins) WPI responses was implemented, and a support vector machine-recursive feature elimination (SVM-RFE) algorithm was used to model relevant metabolites by ethnicity and IPFD classes. Metabolic network analysis identified glycine as a central hub in both ethnicity and IPFD WPI response networks. A depletion of glycine relative to WPI concentration was detected in Chinese and high IPFD participants independent of BMI. Urea cycle metabolites were highly represented among the ethnicity WPI metabolome model, implicating a dysregulation in ammonia and nitrogen metabolism among Chinese participants. Uric acid and purine synthesis pathways were enriched within the high IPFD cohort's WPI metabolome response, implicating adipogenesis and insulin resistance pathways. In conclusion, the discrimination of ethnicity from WPI metabolome profiles was a stronger prediction model than IPFD in overweight women with prediabetes. Each models' discriminatory metabolites enriched different metabolic pathways that help to further characterize prediabetes in Asian Chinese women and women with increased IPFD, independently.

Exposure to High-Fat Style Diet Induced Renal and Liver Structural Changes, Lipid Accumulation and Inflammation in Intact and Ovariectomized Female Rats

Purpose

We hypothesized that low estrogen levels aggravate obesity-related complications. Diet-induced obesity can cause distinct pathologies, including impaired glucose tolerance, inflammation, and organ injury that leads to fatty liver and chronic kidney diseases. To test this hypothesis, ovariectomized (OVX) rats were fed a high-fat style diet (HFSD), and we examined structural changes and inflammatory response in the kidney and liver.

Methods

Sprague-Dawley female rats were ovariectomized or sham-operated and divided into four groups: sham-operated rats fed a normal diet (ND); ovariectomized rats fed a normal diet (OVX-ND); sham-operated rats fed a HFSD; ovariectomized rats fed a high-fat style diet (OVX-HFSD). Mean blood pressure and fasting blood glucose were measured on weeks 0 and 10. The rats were sacrificed 10 weeks after initiation of ND or HFSD, the kidney and liver were harvested for histological, immunohistochemical and immunofluorescence studies.

Results

HFSD-fed rats presented a significantly greater adiposity index compared to their ND counterparts. Liver index, fasting blood glucose and mean blood pressure was increased in OVX-HFSD rats compared to HFSD rats at study terminal. Histological and morphometric studies showed focal interstitial mononuclear cell infiltration in the kidney of HFSD rats with mesangial expansion being greater in the OVX-HFSD rats. Both HFSD fed groups showed increased expressions of renal inflammatory markers, namely TNF-alpha, IL-6 and MCP-1, and infiltrating M1 macrophages with some influence of ovarian hormonal status. HFSD-feeding also caused hepatocellular steatosis which was aggravated in ovariectomized rats fed the same diet. Furthermore, hepatocellular ballooning was observed only in the OVX-HFSD rats. Similarly, HFSD-fed rats showed increased expressions of the inflammatory markers and M1 macrophage infiltration in the liver; however, only IL-6 expression was magnified in the OVX-HFSD.

Conclusion

Our data suggest that some of the structural changes and inflammatory response in the kidney and liver of rats fed a HFSD are exacerbated by ovariectomy.

The Prevalence and Trend of Metabolic Syndrome in the South-East of Iran

Metabolic syndrome (Mets) is a set of metabolic disorders including abdominal obesity, insulin resistance or disorders of glucose absorption and metabolism, lipid disorders, and hypertension, which increases the risk of chronic diseases including type 2 diabetes, cardiovascular diseases, cancer, and mortality. Therefore, the present study aimed to determine the trend of Mets and its components in Zahedan, a city located in South-East of Iran, from 2009 to 2017. A total of 761 individuals aged >20 years were followed from 2009 to 2017. The frequency of metabolic syndrome was measured at two-time points based on four criteria: International Diabetes Federation (IDF), National Cholesterol Education Program-Third Adult Treatment Panel (NCEP-ATP III), Third Adult Treatment Panel (ATP III), and American Heart Association and the National Heart Lung and Blood Institute (AHA/NHLBI). The prevalence of Mets ranged from 16.6 (95% CI: 13.9 - 19.2) (ATP III) to 23.70% (95% CI: 20.6 - 26.6) (AHA/NHLBI) in 2009. Accordingly, it increased from 5.2% to 7.3% during the study period using different criteria such that the frequency of Mets varied from 21.8 (95% CI: 18.8 - 24.7) (ATP III) to 31.0% (95% CI: 27.7 - 34.3) (AHA/NHLBI) in 2017. The increasing trend was prominent among females, persons aged <40 years, and those with the lowest educational level. Two components of Mets (abdominal obesity and diabetes) increased in prevalence, whereas elevated blood pressure, hypertriglyceridemia, and low HDL declined. The study revealed an annual increase rate of about 1% in the prevalence of metabolic syndrome. Therefore, the increasing trend of some components of Mets highlights the urgency of addressing these components as health priorities.

Waist Circumference and its Changes Are More Strongly Associated with the Risk of Type 2 Diabetes than Body Mass Index and Changes in Body Weight in Chinese Adults

BACKGROUND

The associations of different adiposity indicators and short-term adiposity change with diabetes risk are not fully elucidated.

OBJECTIVE

We aimed to assess the independent and joint effects of different baseline adiposity indicators and short-term body adiposity change on the risk of type 2 diabetes.

METHODS

We prospectively followed 10,419 Chinese adults aged 20-80 y in 2008-2012. Incident diabetes was diagnosed based on fasting glucose, 2-h glucose, or glycated hemoglobin (HbA1c) after an oral glucose tolerance test using the American Diabetes Association standard. Cox proportional hazard regression models were used to assess the associations of adiposity indicators and adiposity change with diabetes risk.

RESULTS

During a mean follow-up of 2.8 y, we identified 805 type 2 diabetes cases. Baseline BMI, waist circumference, and waist-height ratio (WHtR) were all positively associated with diabetes risk. The area under the curve was significantly greater for waist circumference (0.624) and WHtR (0.627) than for BMI (0.608) (P <0.05). Compared with subjects with stable adiposity levels (±2 kg or ± 3 cm in changes in body weight or waist circumference) from baseline to Year 1, those subjects with the most weight gain or the most waist circumference gain had a 1.53-fold or 1.37-fold greater risk of diabetes; those with the most weight loss had a 46% lower risk of diabetes. Furthermore, regardless of baseline weight status, weight or waist circumference change in the first year was associated with diabetes risk.

CONCLUSION

Abdominal adiposity indicators, waist circumference and its change, are more strongly associated with the risk of type 2 diabetes than general adiposity indicators, BMI, and changes in body weight among Chinese adults.

The effects of metformin on simple obesity: a meta-analysis

OBJECTIVE

To evaluate the efficacy of metformin versus a placebo in the treatment of patients with simple obesity without obesity related diseases.

METHODS

A search was done on Pub-Med, EMBASE, Cochrane, and Science Citation Index Expanded databases. The main inclusion criteria included the following:(1) randomized controlled trials. (2) patients diagnosed as being overweight or obese. (3) patients were randomly assigned to receive metformin or control. Exclusion criteria included the following: patients diagnosed with an obesity related disease, such as diabetes mellitus (DM) or polycystic ovary syndrome (PCOS).

RESULTS

Compared with the placebo, weighted mean difference (WMD) was 2.33 (95% CI 0.31, 4.35) kg higher with metformin (p = 0.02). Compared with the placebo, WMD was 0.57 (95% CI 0.35, 0.79) kg/m² higher with metformin(p < 0.00001). There was no significant difference in the reduction of waist circumference between the metformin group and the control group (p = 0.05). The fasting blood glucose levels were significantly lower in the metformin group than in the control group (p < 0.00001). However, no hypoglycemia was noted in the metformin group or the control group.

CONCLUSION

Metformin is effective in reducing body weight of simple obesity patients, and metformin does not induce hypoglycemia as a side effect.

Dysregulated lipid storage and its relationship with insulin resistance and cardiovascular risk factors in non-obese Asian patients with type 2 diabetes

The prevalence of non-obese type 2 diabetes in Asians is up to 50%. This review aims to summarize the role of regional fat in the development of insulin resistance and cardiovascular risk in non-obese Asian type 2 diabetes as well as the role of intra-pancreatic fat and β-cell dysfunction. The body fat content of non-obese Asian type 2 diabetic patients is not different from that of non-diabetic subjects but the proportion of intra-abdominal and intra-hepatic fat are greater. Visceral fat contributes to insulin resistance and cardiovascular risk in non-obese Asian type 2 diabetes. Intra-hepatic fat and the hypertrophic abdominal subcutaneous adipocytes are associated with insulin resistance and cardiovascular risk in non-obese, non-diabetic Asian subjects. It may be true in non-obese Asian type 2 diabetic patients. The role of intra-myocellular lipid and insulin resistance is uncertain. Intra-pancreatic fat may not be involved in β-cell dysfunction in non-obese Asian type 2 diabetes.

Secular Trend of Metabolic Syndrome and Its Components in a Cohort of Iranian Adults from 2001 to 2013

BACKGROUND

Metabolic syndrome (MetS) and its components increase the risk of developing cardiovascular diseases, type 2 diabetes, and all-cause mortality. Reports on the trends of MetS and its components in longitudinal studies are scarce, especially in low- and middle-income countries. This study was designed to investigate the prevalence and trends of MetS and its components in a cohort of Iranian adults from 2001 to 2013.

METHODS

Participants were followed up for 12 years in a longitudinal population-based study of 6500 adults aged 35 years and older in 2001. Participants were randomly selected from three provinces in central Iran. Sociodemographic characteristics, anthropometry, blood pressure, and various biochemical indices were collected in 2001, 2007, and 2013. Secular trend and age-adjusted trend of MetS and its components were calculated from 2001 to 2013.

RESULTS

The standardized prevalence of MetS, hypertension, low high-density lipoprotein cholesterol (HDL-C), abdominal obesity, and diabetes/impaired glucose tolerance (IGT) increased over the 12 years (6.9%, 5.5%, 12.0%, 2.3%, and 18.7%, respectively), while the prevalence of hypertriglyceridemia decreased by 15.5% during this period. The prevalence of MetS, low HDL-C, and abdominal obesity were higher in females than males in all three phases. Moreover, the increases in the prevalence of these metabolic abnormalities were higher in the rural population than in the urban population.

CONCLUSIONS

The present study underscored the increasing trends in MetS and most of its risk factors, thus, to prevent an increase in the cardiovascular risk factors, there is a need to improve lifestyle by education, screening, and treatment of abnormalities.

Intra-abdominal fat. Part II: Non-cancerous lesions of the adipose tissue localized beyond organs

Adipose tissue does not belong to the most favorite structures to be visualized by ultrasound. It is not, however, free from various pathologies. The aim of this paper is to make abdominal cavity examiners more familiar with non-cancerous lesions found in intra-abdominal fat. The main focus is lesions that are rarely discussed in the literature. Visceral adiposity is one of important pathogenetic factors contributing to cardiovascular events, metabolic syndrome and even certain neoplasms. That is why this article exposes sonographic features that are the most characteristic of these lesions. The value of ultrasonography in the diagnosis of this pathology is underestimated, and a number of US scan reports do not reflect its presence in any way. Moreover, the article discusses more and more common mesenteritis, the lack of knowledge of which could pose difficulties in explaining the nature of symptoms reported by patients. Furthermore, this review presents lesions referred to in the literature as focal infarction of intra-abdominal fat. This section focuses on infarction of the greater and lesser omentum, epiploic appendagitis, mesenteric volvulus and focal fat necrosis resulting from pancreatitis. These lesions should be assessed with respect to the clinical context, and appropriate techniques of ultrasonography should be employed to allow careful determination of the size, shape, acoustic nature and location of lesions in relation to the integuments and large bowel, as well as their reaction to compression with an ultrasound transducer and behavior during deep inspiration. Moreover, each lesion must be obligatorily assessed in terms of blood flow. Doppler evaluation enables the differentiation between primary and secondary inflammation of intra-abdominal fat. The paper also draws attention to a frequent indirect sign of a pathological process, i.e. thickening and hyperechogenicity of fat, which sometimes indicates an ongoing pathology at a deeper site. This structure may completely conceal the primary lesion rendering it inaccessible for ultrasound. In such cases and in the event of other doubts, computed tomography should be the next diagnostic step.

Does the impact of metabolic syndrome on cardiovascular events vary by using different definitions?

BACKGROUND

Metabolic Syndrome (MetS) is a complex disorder which increases the risk of chronic diseases, including cardiovascular diseases and diabetes mellitus. As a result of modern lifestyles, the prevalence of MetS has been rising globally. This study aims to investigate whether overall prevalence of MetS varies when using different definitions of MetS and to identify the best and most predictive definition of the MetS for cardiovascular disease (CVD) events over 10 years in a cohort of an Iranian population.

METHOD

Adults aged ≥ 35 years from urban and rural regions in central Iran were selected at baseline and followed up for more than 10 years. Data on socio-demographic characteristics, anthropometry, blood pressure and smoking status were collected at baseline. In addition, various biochemical indices were assessed. MetS was defined based on five available definitions, and cardiovascular events during 10 years follow up were confirmed by an expert group. The hazard ratios were calculated by the Cox proportional hazards model.

RESULTS

The highest prevalence of MetS was observed by using AHA-NHBI definition (36.9%), followed by JIS definition (31.2%). On the other hand, EGIR (8.8%) provided the lowest prevalence. The risk of developing CVD, irrespective of definitions, was approximately two fold higher in the presence of MetS. After controlling for possible confounders, AHA-NHBI definition was found to be the best predictor of CVD.

CONCLUSION

This study demonstrated a great variability in the prevalence of MetS among Iranian adults when using different definitions of MetS. CVD risk was significantly higher in MetS participants, as well as in participants with any risk factors of MetS; however, the AHA-NHBI definition was found to be the best predictor of CVD. Thus protective measures, including lifestyle modifications, plus control of individual risk factors is necessary to prevent cardiovascular events.

Estrogen signaling in metabolic inflammation

There is extensive evidence supporting the interference of inflammatory activation with metabolism. Obesity, mainly visceral obesity, is associated with a low-grade inflammatory state, triggered by metabolic surplus where specialized metabolic cells such as adipocytes activate cellular stress initiating and sustaining the inflammatory program. The increasing prevalence of obesity, resulting in increased cardiometabolic risk and precipitating illness such as cardiovascular disease, type 2 diabetes, fatty liver, cirrhosis, and certain types of cancer, constitutes a good example of this association. The metabolic actions of estrogens have been studied extensively and there is also accumulating evidence that estrogens influence immune processes. However, the connection between these two fields of estrogen actions has been underacknowledged since little attention has been drawn towards the possible action of estrogens on the modulation of metabolism through their anti-inflammatory properties. In the present paper, we summarize knowledge on the modification inflammatory processes by estrogens with impact on metabolism and highlight major research questions on the field. Understanding the regulation of metabolic inflammation by estrogens may provide the basis for the development of therapeutic strategies to the management of metabolic dysfunctions.

Evaluation of adiposity-related biomarkers as metabolic syndrome indicators

Recent studies have suggested a relationship of the increased circulating adipokines and inflammatory cytokine, and the risk of metabolic syndrome (MetS). The objective of this study was to identify adiposity-related factors that reflect MetS in order to establish early intervention targets. We performed a cross-sectional study which included 108 MetS subjects and 91 controls. Blood adiponectin, leptin, vascular-, and intercellular adhension molecules (VCAM, ICAM), monocyte chemoattractant protein 1 (MCP1), high-sensitivity C-reactive protein (hsCRP), oxidized LDL (oxLDL), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured. The correlation analysis indicated that the MetS score (sum of the number of MetS risk factors) had an inverse relationship with adiponectin (p < 0.0001), and positive correlations with leptin (p < 0.05), ICAM (p < 0.01), MCP1 (p < 0.05), oxLDL (p < 0.05), TNF-α (p < 0.0001), IL-6 (p < 0.05) and hsCRP (p < 0.01). In multivariate logistic regression analyses, plasma triglyceride (TG) was independently associated with adiponectin, ICAM and TNF-α with the standardized β coefficients of -0.213, 0.197, and 0.193, respectively. Plasma HDL-cholesterol was independently associated with ICAM and hsCRP with the standardized β coefficients of -0.150 and -0.173. Adiponectin, TNF-α, and hsCRP were the most proximate markers reflecting MetS. Among MetS components, TG and HDL-cholesterol concentrations displayed the relationship with inflammatory markers measured in this study.

Inflammation and metabolic dysfunction: links to cardiovascular diseases

Abdominal obesity is a major risk factor for cardiovascular disease, and recent studies highlight a key role of adipose tissue dysfunction, inflammation, and aberrant adipokine release in this process. An increased demand for lipid storage results in both hyperplasia and hypertrophy, finally leading to chronic inflammation, hypoxia, and a phenotypic change of the cellular components of adipose tissue, collectively leading to a substantially altered secretory output of adipose tissue. In this review we have assessed the adipo-vascular axis, and an overview of adipokines associated with cardiovascular disease is provided. This resulted in a first list of more than 30 adipokines. A deeper analysis only considered adipokines that have been reported to impact on inflammation and NF-κB activation in the vasculature. Out of these, the most prominent link to cardiovascular disease was found for leptin, TNF-α, adipocyte fatty acid-binding protein, interleukins, and several novel adipokines such as lipocalin-2 and pigment epithelium-derived factor. Future work will need to address the potential role of these molecules as biomarkers and/or drug targets.

A randomized comparative 96-week trial of boosted atazanavir versus continued boosted protease inhibitor in HIV-1 patients with abdominal adiposity

BACKGROUND

Abdominal adiposity in HIV-1 patients initiating antiretroviral therapy may be part of a restoration-to-health phenomenon. Lipoatrophy is associated with long-term thymidine analogue therapy. Individual protease inhibitors (PIs) differ in their effects on lipids and insulin resistance.

METHODS

A randomized open-label multicentre 96-week trial compared changes in fat distribution in patients with suppressed HIV-1 RNA and abdominal adiposity, who either continued on their current twice-daily ritonavir-boosted PI (PI/r) or switched to once-daily boosted atazanavir (ATV/r). Treatment with two nucleoside reverse transcriptase inhibitors was unchanged. Body composition was assessed by dual-energy x-ray absorptiometry (DEXA) and abdominal computerized tomography (CT) scanning.

RESULTS

In total, 201 patients were randomized; 131 switched to ATV/r. Viral suppression (<50 copies/ml) was similarly maintained (93% ATV/r versus 89% PI/r). Mean changes from baseline in trunk-to-limb fat ratio were similar; difference estimates 0.03 (95% CI -0.06, 0.12; P=0.48 at week 48) and 0.02 (95% CI -0.10, 0.14; P=0.73 at week 96). More patients in the PI/r arm had a decrease of ≥20% in limb fat from baseline at week 96. Significantly greater reductions in proatherogenic lipids occurred following switch to ATV/r. Both treatment regimens were generally well-tolerated; the incidence of grade 3-4 treatment-related clinical adverse events was 34% among ATV/r recipients versus 4% of PI/r-treated patients.

CONCLUSIONS

Switching to ATV/r had no demonstrable benefit on abdominal adiposity. Maintenance of efficacy, less limb fat loss and marked reduction in proatherogenic lipids was observed with ATV/r compared with continuing a PI/r regimen.

In anorexia nervosa, even a small increase in abdominal fat is responsible for the appearance of insulin resistance

CONTEXT

The aim of treatment in patients affected by anorexia nervosa (AN) is weight recovery. However, during weight gain, anorectic patients' body composition is changed, with an increase in abdominal fat, particularly in the visceral compartment.

OBJECTIVE

We hypothesized that changes in body composition, particularly in abdominal fat, are responsible for the variability in insulin sensitivity (IS) in different stages of AN.

DESIGN AND MEASUREMENTS

We compared 20 anorectic patients in the acute stage, 19 in the weight-recovery stage and 21 controls. All subjects underwent an oral glucose tolerance test, hyperinsulinaemic euglycaemic clamp and dual energy X-ray absorptiometry to measure body composition.

RESULTS

The percentage of trunk fat was higher in weight recovery than in the acute phase (47·7 ± 8·4%vs 34·6 ± 7·6%; P ≤ 0·01) and in the control group (33·4 ± 7·6; P < 0·01 vs weight recovery). Although the recovery group gained weight, their body mass index (BMI) was not statistically different from that of the acute group (14·4 ± 1·1 vs 13·6 ± 1·8 kg/m(2) ). Insulin sensitivity was lower in the weight-recovery group than the acute group (4·7 ± 1·5 vs 7·8 ± 1·6 mg/kg/min; P < 0·01) and controls (7·7 ± 1·4 mg/kg/min; P < 0·01). A linear negative correlation was found between IS and the percentage of abdominal fat in the weight-recovery and acute groups (r = -0·51; P = 0·04 and r = -0·53; P = 0·04 respectively), while IS did not correlate with BMI.

CONCLUSION

Although weight-recovery represents the main aim of treatment in AN, refeeding is associated with an increase in abdominal fat which might be responsible of the onset of insulin resistance. As BMI and weight-recovery were associated with impaired IS, they cannot be considered the only aim of treatment of AN.

Linkage of angiotensinogen gene polymorphisms with hypertension in a sibling study of Hong Kong Chinese

OBJECTIVE

The angiotensinogen gene has been linked with human essential hypertension in whites but the relationship in Asian populations has been less consistent. This study aimed to examine genetic associations between hypertension and the M235T, T174M, and G-217A polymorphisms of the angiotensinogen gene in Chinese siblings.

METHODS

We studied members of 126 families with a hypertensive proband, including 434 siblings, of which 178 were hypertensive. Parental history of hypertension was recorded. The M235T, T174M, and G-217A polymorphisms were examined using a microarray method, validated by sequencing. The transmission disequilibrium test was applied to identify whether the genetic polymorphism loci were related to hypertension. Haplotype analysis of the combined polymorphisms was applied using the TRANSMIT program. Linkage study was conducted by applying the affected pedigree member method.

RESULTS

A significant overtransmission was observed for the T235 allele at the M235T polymorphism and hypertension (chi2 = 4.41, P = 0.036) but not for the T174M and G-217A polymorphisms. The haplotype analysis showed a significant association with the haplotypes of paired markers (T174 and T235) with chi2 value of 8.131 (P = 0.004; global test chi2 = 9.131, P = 0.028). Linkage between M235T and hypertension was detected (T = -2.25, P = 0.019), and a tendency for linkage with central obesity-related hypertension was found for the M235T and T174M polymorphisms (P = 0.0087 and P = 0.01).

CONCLUSION

The M235T and T174M variants, especially the T235 allele, contribute to an increased risk of hypertension in these Chinese patients.

Chronic inflammation in obesity and the metabolic syndrome

The increasing incidence of obesity and the metabolic syndrome is disturbing. The activation of inflammatory pathways, used normally as host defence, reminds the seriousness of this condition. There is probably more than one cause for activation of inflammation. Apparently, metabolic overload evokes stress reactions, such as oxidative, inflammatory, organelle and cell hypertrophy, generating vicious cycles. Adipocyte hypertrophy, through physical reasons, facilitates cell rupture, what will evoke an inflammatory reaction. Inability of adipose tissue development to engulf incoming fat leads to deposition in other organs, mainly in the liver, with consequences on insulin resistance. The oxidative stress which accompanies feeding, particularly when there is excessive ingestion of fat and/or other macronutrients without concomitant ingestion of antioxidant-rich foods/beverages, may contribute to inflammation attributed to obesity. Moreover, data on the interaction of microbiota with food and obesity brought new hypothesis for the obesity/fat diet relationship with inflammation. Beyond these, other phenomena, for instance psychological and/or circadian rhythm disturbances, may likewise contribute to oxidative/inflammatory status. The difficulty in the management of obesity/metabolic syndrome is linked to their multifactorial nature where environmental, genetic and psychosocial factors interact through complex networks.

Men develop more intraabdominal obesity and signs of the metabolic syndrome after hyperalimentation than women

We prospectively studied the effects of fast food-based hyperalimentation on insulin sensitivity and components of the metabolic syndrome and analyzed this with respect to sex. Twelve nonobese men and 6 nonobese women (26 +/- 6.6 years old), and an age-matched control group were recruited. Subjects in the intervention group aimed for 5% to 15% weight increase by doubling their regular caloric intake based on at least 2 fast food meals a day while also adopting a sedentary lifestyle for 4 weeks (<5000 steps a day). Weight of subjects in the intervention group increased from 67.6 +/- 9.1 to 74.0 +/- 11 kg (P < .001), with no sex difference with regard to this or with respect to changes of total abdominal fat volumes or waist circumferences. Fasting insulin (men: before, 3.8 +/- 1.7 microU/mL; after, 7.4 +/- 3.1 microU/mL; P = .004; women: before, 4.9 +/- 2.3 microU/mL; after, 5.9 +/- 2.8 microU/mL; P = .17), systolic blood pressure (men: before, 117 +/- 13 mm Hg; after, 127 +/- 9.1 mm Hg; P = .002; women: before, 102 +/- 5.1 mm Hg; after, 98 +/- 5.4 mm Hg; P = .39), serum low-density lipoprotein cholesterol, and apolipoprotein B increased only in the men of the intervention group. The sex differences in the metabolic responses to the intervention were linked to a considerable difference in the fat accumulation pattern; 41.4% +/- 9.2% of the increase of the fat volume in the abdominal region was accumulated intraabdominally in men and 22.7 +/- 6.5% in women (P < .0001). This study thus showed that women are protected, compared with men, against developing intraabdominal obesity when adopting a standardized obesity-provoking lifestyle. Our findings suggest that it is not different lifestyles and/or behaviors that underlie the fact that men have a higher cardiovascular risk at the same level of percentage of body fat than women.

Defective mitochondrial biogenesis: a hallmark of the high cardiovascular risk in the metabolic syndrome?

The metabolic syndrome is a group of risk factors of metabolic origin that are accompanied by increased risk for type 2 diabetes mellitus and cardiovascular disease. These risk factors include atherogenic dyslipidemia, elevated blood pressure and plasma glucose, and a prothrombotic and proinflammatory state. The condition is progressive and is exacerbated by physical inactivity, advancing age, hormonal imbalance, and genetic predisposition. The metabolic syndrome is a particularly challenging clinical condition because its complex molecular basis is still largely undefined. Impaired cell metabolism has, however, been suggested as a relevant pathophysiological process underlying several clinical features of the syndrome. In particular, defective oxidative metabolism seems to be involved in visceral fat gain and in the development of insulin resistance in skeletal muscle. This suggests that mitochondrial function may be impaired in the metabolic syndrome and, thus, in the consequent cardiovascular disease. We have recently found that mitochondrial biogenesis and function are enhanced by nitric oxide in various cell types and tissues, including cardiac muscle. Increasing evidence suggests that this mediator acts as a metabolic sensor in cardiomyocytes. This implies that a defective production of nitric oxide might be linked to dysfunction of the cardiomyocyte metabolism. Here we summarize some recent findings and propose a hypothesis for the high cardiovascular risk linked to the metabolic syndrome.

Mesenteric fat thickness as an independent determinant of fatty liver

OBJECTIVE

Mesenteric fat is drained by the portal circulation and has been suggested to be a key component in obesity-related health risk, notably the metabolic syndrome. There are increasing epidemiological and experimental data showing that fatty liver is another component of this multifaceted syndrome. Given their intimate anatomical and physiological relationships, we hypothesized that mesenteric fat thickness may be independently associated with the risk of fatty liver. To test this hypothesis, we examined the predictive role of various fat deposits including mesenteric fat thickness, and various metabolic variables on the risk of fatty liver.

SUBJECTS AND METHODS

A total of 291 Chinese subjects (134 men and 157 women with a mean BMI of 23.7 kg/m2, range: 16.5-33.4 kg/m2) underwent ultrasound examination for measurement of mesenteric, subcutaneous and preperitoneal fat thickness, and for diagnosis of fatty liver. Body mass index, waist circumference, and waist-hip ratio were recorded. Blood pressure was measured. Fasting plasma glucose, insulin resistance, high-density lipoprotein cholesterol (HDL-C), triglycerides, low-density lipoprotein cholesterol (LDL-C), liver enzymes were determined by common methods.

RESULTS

The subjects with fatty liver had greater abdominal fat thickness and higher anthropometric indexes than those without fatty liver. The subjects with fatty liver also showed higher blood pressure, worse lipid and glycaemic profile compared with those without fatty liver. Using multiple logistic regression analysis, mesenteric fat thickness was a risk factor of fatty liver, independent of body mass index, age, sex, insulin resistance, fasting plasma glucose, lipid and blood pressure. The odds ratio was 1.5 (95% confidence interval: 1.27-1.77) for every 1 mm increase in the mesenteric fat thickness. Measurement of preperitoneal and subcutaneous fat deposits did not show significant associations with fatty liver.

CONCLUSION

Mesenteric fat thickness measured on ultrasound is an independent determinant of fatty liver.

Physiological and pathophysiological regulation of regional adipose tissue in the development of insulin resistance and type 2 diabetes

AIM

To survey the latest state of knowledge concerning the regulation of regional adipocytes and their role in the development of insulin resistance and type 2 diabetes.

METHODS

Data from the English-language literature on regional adipocytes, including abdominal, intramyocellular, intrahepatic and intra-islet fat as well as the adipokines and their relations to insulin resistance and type 2 diabetes, were reviewed.

RESULTS

It is not the total amount of fat but the fat that resides within skeletal muscle cell (intramyocellular fat), hepatocytes and intra-abdominally (visceral fat), via systemic and local secretion of several adipokines, that influences insulin resistance. Among the adipokines that relate to insulin resistance, adiponectin and leptin appear to have clinical relevance to human insulin resistance and others may also contribute, but their role is still inconclusive. The intra-islet fat also adversely affects beta-cell function and number (beta-cell apoptosis), eventually leading to deterioration of glucose tolerance. The abnormal location of fat observed in patients with type 2 diabetes and their relatives is conceivably partly the results of the genetically determined, impaired mitochondrial fatty acid oxidative capacity. Restriction or elimination of the fat load by weight control, regular exercise and thiazolidinediones has been shown to improve insulin resistance and beta-cell function and to delay the development of type 2 diabetes.

CONCLUSION

These data support the plausibility of an essential role of regional adipose tissue in the development of insulin resistance and type 2 diabetes.

Mesenteric fat thickness is an independent determinant of metabolic syndrome and identifies subjects with increased carotid intima-media thickness

OBJECTIVE

Mesenteric fat, a reflection of visceral adiposity, may play an important role in the pathogenesis of metabolic syndrome and cardiovascular diseases (CVD). In this study, we examined the independent relationship between mesenteric fat thickness and metabolic syndrome and defined its optimal cutoff value to identify high-risk subjects for metabolic syndrome and CVD.

RESEARCH DESIGN AND METHODS

A total of 290 Chinese subjects had an ultrasound examination for measurements of thickness of mesenteric, preperitoneal, and subcutaneous fat as well as carotid intima-media thickness (IMT). Anthropometric measurements and metabolic risk profile were assessed by physical examination and blood taking.

RESULTS

Twenty (6.9%) subjects had metabolic syndrome according to the National Cholesterol Education Panel Adult Treatment Panel III criteria with Asian definitions for central obesity (waist circumference >80 cm in women and >90 cm in men). Mesenteric fat thickness had significant correlations (P < 0.05) with various metabolic variables. On multivariate regression, mesenteric fat thickness was an independent determinant of all components of metabolic syndrome after adjustment for age, sex, homeostasis model assessment of insulin resistance, and other fat deposits. The odds ratio of metabolic syndrome was increased by 1.35 (95% CI 1.10-1.66)-fold for every 1-mm increase in mesenteric fat thickness. On receiver-operating characteristic curve analysis, mesenteric fat thickness of > or =10 mm was the optimal cutoff value to identify metabolic syndrome, with sensitivity of 70% and specificity of 75%. Subjects with mesenteric fat thickness > or =10 mm had higher carotid IMT than those with thickness <10 mm (0.73 +/- 0.19 vs. 0.64 +/- 0.16 mm, P = 0.001).

CONCLUSIONS

Mesenteric fat thickness was an independent determinant of metabolic syndrome and identified subjects with increased carotid IMT.

Electroacupuncture therapy for weight loss reduces serum total cholesterol, triglycerides, and LDL cholesterol levels in obese women

Our purpose in this study was to investigate the effect of acupuncture therapy on body weight and on levels of the serum total cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol in obese women. Fifty-five women were studied in three groups as follows: (1) control group (n = 12; mean age = 43.3 +/- 4.3, and mean body mass index {BMI} = 32.2 +/- 3.4); (2) electroacupuncture (EA) (n = 22; mean age = 39.8 +/- 5.3, and BMI = 34.8 +/- 3.3); and (3) diet restriction (n = 21; mean age = 42.7 +/- 3.9, and BMI = 34.9 +/- 3.3). EA was performed using the ear points, Sanjiao (Hungry) and Shen Men (Stomach), and the body points, LI 4, LI 11, St 25, St 36, St 44 and Liv 3, once daily, for 30 minutes, for 20 days, whereas patients on diet restriction had a 1425 Kcal diet program, that consisted of 1425 Kcal daily for 20 days. There was a 4.8% weight reduction in patients with EA application, whereas patients on diet restriction had a 2.5% weight reduction. There were significant decreases in total cholesterol and triglyceride levels in EA and diet groups compared with the control group (p < 0.05 in both cases). Furthermore, there was a decrease in LDL levels in the EA group compared with the control group (p < 0.05). No significant changes could be found in HDL levels among the three groups. Our results suggest that EA application in obese women may decrease the serum total cholesterol, triglyceride, and LDL cholesterol levels by increasing the serum beta endorphin level. This lipolytic effect of EA may also reduce the morbidity of obesity by mobilizing the energy stores that result in weight reduction.

Intra-abdominal fat is a major determinant of the National Cholesterol Education Program Adult Treatment Panel III criteria for the metabolic syndrome

The underlying pathophysiology of the metabolic syndrome is the subject of debate, with both insulin resistance and obesity considered as important factors. We evaluated the differential effects of insulin resistance and central body fat distribution in determining the metabolic syndrome as defined by the National Cholesterol Education Program (NCEP) Adult Treatment Panel III. In addition, we determined which NCEP criteria were associated with insulin resistance and central adiposity. The subjects, 218 healthy men (n = 89) and women (n = 129) with a broad range of age (26-75 years) and BMI (18.4-46.8 kg/m2), underwent quantification of the insulin sensitivity index (Si) and intra-abdominal fat (IAF) and subcutaneous fat (SCF) areas. The metabolic syndrome was present in 34 (15.6%) of subjects who had a lower Si [median: 3.13 vs. 6.09 x 10(-5) min(-1)/(pmol/l)] and higher IAF (166.3 vs. 79.1 cm2) and SCF (285.1 vs. 179.8 cm2) areas compared with subjects without the syndrome (P < 0.001). Multivariate models including Si, IAF, and SCF demonstrated that each parameter was associated with the syndrome. However, IAF was independently associated with all five of the metabolic syndrome criteria. In multivariable models containing the criteria as covariates, waist circumference and triglyceride levels were independently associated with Si and IAF and SCF areas (P < 0.001). Although insulin resistance and central body fat are both associated with the metabolic syndrome, IAF is independently associated with all of the criteria, suggesting that it may have a pathophysiological role. Of the NCEP criteria, waist circumference and triglycerides may best identify insulin resistance and visceral adiposity in individuals with a fasting plasma glucose <6.4 mmol/l.