Relationship of adiposity with arterial stiffness as mediated by adiponectin in older men and women: the Hoorn Study

Relationships between body fat distribution and metabolic syndrome traits and outcomes: A mendelian randomization study

BACKGROUND

Obesity is a complex, multifactorial disease associated with substantial morbidity and mortality worldwide. Although it is frequently assessed using BMI, many epidemiological studies have shown links between body fat distribution and obesity-related outcomes. This study examined the relationships between body fat distribution and metabolic syndrome traits using Mendelian Randomization (MR).

METHODS/FINDINGS

Genetic variants associated with visceral adipose tissue (VAT), abdominal subcutaneous adipose tissue (ASAT), and gluteofemoral adipose tissue (GFAT), as well as their relative ratios, were identified from a genome wide association study (GWAS) performed with the United Kingdom BioBank. GWAS summary statistics for traits and outcomes related to metabolic syndrome were obtained from the IEU Open GWAS Project. Two-sample MR and BMI-controlled multivariable MR (MVMR) were performed to examine relationships between each body fat measure and ratio with the outcomes. Increases in absolute GFAT were associated with a protective cardiometabolic profile, including lower low density lipoprotein cholesterol (β: -0.19, [95% CI: -0.28, -0.10], p < 0.001), higher high density lipoprotein cholesterol (β: 0.23, [95% CI: 0.03, 0.43], p = 0.025), lower triglycerides (β: -0.28, [95% CI: -0.45, -0.10], p = 0.0021), and decreased systolic (β: -1.65, [95% CI: -2.69, -0.61], p = 0.0019) and diastolic blood pressures (β: -0.95, [95% CI: -1.65, -0.25], p = 0.0075). These relationships were largely maintained in BMI-controlled MVMR analyses. Decreases in relative GFAT were linked with a worse cardiometabolic profile, with higher levels of detrimental lipids and increases in systolic and diastolic blood pressures.

CONCLUSION

A MR analysis of ASAT, GFAT, and VAT depots and their relative ratios with metabolic syndrome related traits and outcomes revealed that increased absolute and relative GFAT were associated with a favorable cardiometabolic profile independently of BMI. These associations highlight the importance of body fat distribution in obesity and more precise means to categorize obesity beyond BMI.

The negative association of lower body fat mass with cardiometabolic disease risk factors is partially mediated by adiponectin

Gluteofemoral fat correlates negatively with a number of cardiometabolic disease risk factors, but the mechanisms involved in these relationships are unknown. The aim of this study was to test the hypothesis that gluteofemoral fat attenuates the risk of cardiometabolic disease by increasing blood adiponectin levels. This was a cross-sectional study in which arm, leg, gluteofemoral, abdominal s.c. and visceral fat levels were measured by dual-energy X-ray absorptiometry in 648 African females. Fasting serum adiponectin, lipid, insulin and plasma glucose levels and blood pressure were measured. Relationships between variables were analysed using multivariable linear regression and structural equation modelling. Adiponectin correlated positively (β = 0.45, P < 0.0001) with gluteofemoral fat in a multivariable regression model that included age, height, and arm, s.c. and visceral fat levels. In further regression models, there was a negative correlation of gluteofemoral fat with fasting glucose (β = -0.28; P < 0.0001) and triglyceride levels (β = -0.29; P < 0.0001) and insulin resistance (HOMA; β = -0.26; P < 0.0001). Structural equation modelling demonstrated that adiponectin mediated 20.7% (P < 0.01) of the association of gluteofemoral fat with insulin resistance and 16.1% (P < 0.01) of the association with triglyceride levels but only 6.67% (P = 0.31) of the association with glucose levels. These results demonstrate that gluteofemoral and leg fat are positively associated with adiponectin levels and that the negative association of lower body fat with insulin resistance and triglyceride levels may partially be mediated by this adipokine. Further studies are required to determine other factors that mediate the effect of lower body fat on cardiometabolic disease risk factors.

Genetically predicted body fat mass and distribution with diabetic kidney disease: A two-sample Mendelian randomization study

The aim of this study is to apply a Mendelian randomization (MR) design to investigate the potential causal associations between the body mass index (BMI), body fat mass such as trunk fat mass and waist circumference (WC), and diabetic kidney disease (DKD). A two-sample MR study was conducted to obtain exposure and outcome data from previously published studies. The instrumental variables for BMI, trunk fat mass, and WC were selected from genome-wide association study datasets based on summary-level statistics. The random-effects inverse-variance weighted (IVW) method was used for the main analyses, and the weighted median and MR-Egger approaches were complementary. In total, three MR methods suggested that genetically predicted BMI, trunk fat mass, and WC were positively associated with DKD. Using IVW, we found evidence of causal relationships between BMI [odds ratio (OR) = 1.99; 95% confidence interval (CI), 1.47–2.69; p = 7.89 × 10−6], trunk fat mass (OR = 1.80; 95% CI, 1.28–2.53; p = 6.84 × 10−4), WC (OR = 2.48; 95% CI, 1.40–4.42; p = 1.93 × 10−3), and DKD. MR-Egger and weighted median regression also showed directionally similar estimates. Both funnel plots and MR-Egger intercepts showed no directional pleiotropic effects involving the aforementioned variables and DKD. Our MR analysis supported the causal effect of BMI, trunk fat mass, and WC on DKD. Individuals can substantially reduce DKD risk by reducing body fat mass and modifying their body fat distribution.

Sex-different changes of body composition in aging: a systemic review

OBJECTIVE

Aging causes changes in body composition, in which differences in the distribution and amount of fat and muscle tissue affect the development of various diseases according to sex. We conducted a systemic review of the literature and examined the relationship between body composition differences and related health conditions or diseases in older men and women.

METHODS

Three different electronic databases (MEDLINE, Web of Science, and Embase) were used to find articles from 2000 until March 2022. Information on the study design characteristics, setting, measure of body composition, and health outcomes was extracted.

RESULTS

A total of 217 articles were retrieved, and 28 studies met the inclusion criteria. The included studies showed that older men have larger skeletal muscle mass (sMM) than women, while older women have larger fat mass (FM) than men. sMM has a favorable effect on physical performance, bone density, metabolism, cognitive function, and mortality in both men and women; however, the effects of sMM in women are less significant and even negligible compared to those in men. FM is significantly unfavorable for physical performance in women but sometimes favorable or unfavorable for glucose level and cognitive and lung function according to location. FM in men is usually less important for function, bone density, glucose level, and cognitive function than in women.

CONCLUSION

Changes in muscle and fat distribution according to aging and their correlation with health outcomes differ according to sex. Muscle mass may not always be favorable, and fat mass may not always be unfavorable in older adults.

A Physiological Approach to Inflammatory Markers in Obesity

Obesity is one of the most critical health problems all over the world; it is associated with metabolic dysfunction and overnutrition. Changes in the physiological function of adipose tissue, leading to altered secretion of adipocytokines, inflammatory mediators release, and chronic low-grade inflammation, are seen in obesity. Macrophages, neutrophils, CD4+ and CD8+ T cells, B cells, natural killer T (NKT) cells, eosinophils, mast cells, and adipocytes are involved in the inflammatory response that occurs during obesity. Various inflammatory markers are released from these cells. In this chapter, we will mention inflammatory mechanisms and markers of obesity.

Ectopic Fat Depots: Physiological Role And Impact On Cardiovascular Disease Continuum

Obesity is a non-infectious pandemic. The visceral distribution of adipose tissue is a significant factor in the development of cardiovascular diseases and their complications. Along with the visceral abdominal depot in omentum and subcutaneous tissue, there are other ectopic adipose tissue depots: epicardial adipose tissue (EAT), perivascular adipose tissue (PVAT) and perirenal adipose tissue. This article presents a review of the physiological role and molecular basis of the PVAT and EAT function in healthy, as well as in pathological, conditions; the interaction of adipokines and cytokines, their contribution to the development and progression of cardiovascular diseases. The review discusses well-known facts and controversial issues in this field. Comprehensive investigation of the mechanisms of vascular and myocardial pathology in obese people, along with identification of biomarkers for early prediction of cardiovascular complications, would contribute to the development of targeted preventive measures and choice of therapeutic strategies, which is consistent with the contemporary concept of personalized medicine. We have analyzed domestic and foreign literature sources in eLIBRARY and PubMed scientific libraries for the period of 2001-2020.

Gender Difference in the Relationship Between Pulse Pressure and Visceral Adiposity Index in Korean Adults

Background: This study was conducted to assess the association of pulse pressure (PP) and visceral adiposity index (VAI) by gender in Korean adults. Methods: This study used the data of 4960 adults at age ≥20 years, from the 2015 Korean National Health and Nutrition Examination Survey. Results: In the overall population (n = 4960), after adjustment for related variables and with quartile 1 of VAI as a reference, the odds ratios of high PP (PP >60 mmHg) was significantly higher in quartile 3 [1.32 (95% confidence interval [CI], 1.02-1.71)] and quartile 4 of VAI [1.40 (95% CI, 1.07-1.83)]. In women (n = 2784), the OR of high PP, with quartile 1 of VAI as a reference, was significantly higher in quartile 3 [2.36 (95% CI, 1.55-3.61)] and quartile 4 of VAI [2.70 (95% CI, 1.77-4.12)]. In men (n = 2176), high PP was not associated with the quartiles of VAI. In addition, after adjustment for related variables, the PP level was positively associated with the quartiles of VAI in the overall population (P < 0.001) and women (P < 0.001), but not in men (P = 0.316). Conclusions: VAI was positively associated with PP in Korean women, but not in Korean men.

Relationship of Pericardial Fat Tissue With Cardiovascular Risk Factors in Patients Without Cardiovascular Diseases

Background: Obesity and related cardiovascular diseases (CVDs) are important public health problems. The role of visceral ectopic fat remains contested. We studied the relationship between pericardial fat tissue (PFT) volume and CVD risk factors. Methods: We examined 320 patients (average age 63.8 ± 19.9 years) without manifested CVD. Anthropometric indicators were measured, and body mass index (BMI) was calculated. The total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), and triglycerides were assessed. Cardiovascular (CV) risk was calculated using the SCORE system. All patients underwent chest computed tomography with detection of PFT volume using specialized semiautomatic software. Results: Among study participants with normal body mass, the PFT volume was 1.95 cm³ [2.1; 3.9], while it was 3.0 cm³ [2.0; 3.7] in overweight patients and 3.6 cm³ [2.7; 4.7] in obese patients (P < 0.001). Patients with hypertension (HTN) also had significantly higher PFT volumes compared with individuals without HTN: 3.1 cm³ [2.3; 4.15] versus 1.8 cm³ [1.0; 2.5] (P < 0.001). Patients with higher CV risk had significantly higher PFT volume, categorized as follows: 1.6 cm³ [1.0; 2.4], low risk; 2.24 cm³ [2.0; 3.1], moderate risk; 3.1 cm³ [2.4; 3.7], high risk; and 3.9 cm³ [3.0; 5.1], very high risk, respectively (P < 0.001). Results of multiple regression demonstrated that waist circumference and HDL-C were significantly associated with PFT volume. Another model revealed a significant association of BMI and PFT volume with the level of CV risk. Conclusions: This study demonstrates the association of PFT volume with the major diagnostic criteria of obesity, HTN, lipid disorders, and CV risk measured by the SCORE system.

Fat biology and metabolic balance: On the significance of sex

Obesity and its related metabolic disorders have become prevalent and fatal, which are faced by the entire human beings since decades. An energy equilibrium is urgently important for human metabolic health, which requires the participation of multiple organs, such as adipose tissues, liver and skeletal muscles. It seems that both sex and age play a role in the above processes. In this review, we focus on the sexual dimorphism in energy metabolism mediated by adipose tissues, including white and thermogenic (brown/beige) adipose tissues. Remarkably, past investigations have focused on targeting brown/beige adipose tissues to combat obesity because of their contributions to non-shivering thermogenesis. However, sex differences in the regulation of adipose tissue metabolism are likely overlooked. Particularly, increasing data show that males display more visceral fat than females, and females show increased visceral fat after menopause. Visceral adiposity is more deleterious and closely related to metabolic disorders, such as cardiovascular diseases. In this review, we discuss current findings on sexual dimorphism in WAT and BAT biology for a better metabolic balance in humans.

Sex differences in the associations between adiposity distribution and cardiometabolic risk factors in overweight or obese individuals: a cross-sectional study

Background

We aimed to assess the associations between adiposity distribution and cardiometabolic risk factors among overweight and obese adults in China, and to demonstrate the sex differences in these associations.

Methods

A total of 1221 participants (455 males and 766 females) were included in this study. Percentage of body fat (PBF) of the whole body and regional areas, including arm, thigh, trunk, android, and gynoid, were measured by the dual-energy X-ray absorptiometry method. Central adiposity was measured by waist circumference. Clustered cardiometabolic risk was defined as the presence of two or more of the six cardiometabolic risk factors, namely, high triglyceride, low high density lipoprotein, elevated glucose, elevated blood pressure, elevated high sensitivity C-reactive protein, and low adiponectin. Linear regression models and multivariate logistic regression models were used to assess the associations between whole body or regional PBF and cardiometabolic risk factors.

Results

In females, except arm adiposity, other regional fat (thigh, trunk, android, gynoid) and whole-body PBF are significantly associated with clustered cardiometabolic risk, adjusting for age, smoking, alcohol drinking, physical activity, and whole-body PBF. One-SD increase in Z scores of the thigh and gynoid PBF were significantly associated with 80 and 78% lower odds of clustered cardiometabolic risk (OR: 0.20, 95%CI: 0.12–0.35 and OR: 0.22, 95%CI: 0.12–0.41). Trunk, android and whole-body PBF were significantly associated with higher odds of clustered risk with OR of 1.90 (95%CI:1.02–3.55), 2.91 (95%CI: 1.75–4.85), and 2.01 (95%CI: 1.47–2.76), respectively. While in males, one-SD increase in the thigh and gynoid PBF are associated with 94% (OR: 0.06, 95%CI: 0.02–0.23) and 83% lower odds (OR: 0.17, 95%CI: 0.05–0.57) of clustered cardiometabolic risk, respectively. Android and whole-body PBF were associated with higher odds of clustered cardiometabolic risk (OR: 3.39, 95%CI: 1.42–8.09 and OR: 2.45, 95%CI: 1.53–3.92), but the association for trunk PBF was not statistically significant (OR: 1.16, 95%CI: 0.42–3.19).

Conclusions

Adiposity distribution plays an important role in the clustered cardiometabolic risk in participants with overweight and obese and sex differences were observed in these associations. In general, central obesity (measured by android PBF) could be the best anthropometric measurement for screening people at risk for CVD risk factors for both men and women. Upper body fat tends to be more detrimental to cardiometabolic health in women than in men, whereas lower body fat is relatively more protective in men than in women.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-11316-4.

Adipokines and Arterial Stiffness in Obesity

Adipokines are active molecules with pleiotropic effects produced by adipose tissue and involved in obesity-related metabolic and cardiovascular diseases. Arterial stiffness, which is a consequence of arteriosclerosis, has been shown to be an independent predictor of cardiovascular morbidity and mortality. The pathogenesis of arterial stiffness is complex but incompletely understood. Adipokines dysregulation may induce, by various mechanisms, vascular inflammation, endothelial dysfunction, and vascular remodeling, leading to increased arterial stiffness. This article summarizes literature data regarding adipokine-related pathogenetic mechanisms involved in the development of arterial stiffness, particularly in obesity, as well as the results of clinical and epidemiological studies which investigated the relationship between adipokines and arterial stiffness.

The Combination of High Levels of Adiponectin and Insulin Resistance Are Affected by Aging in Non-Obese Old Peoples

BACKGROUND

Adipokine dysregulation is a key feature of insulin resistance and a metabolic syndrome associated with obesity. Low adiponectin levels are associated with higher risks of cardiovascular diseases (CVD). However, high adiponectin levels have also been associated with increased all-cause and cardiovascular mortality in the elderly. This adiponectin paradox has yet to be clarified, which has hindered our understanding of the biological role of adiponectin. Adipokine dysregulation and insulin resistance are also associated with energy-deprivation conditions, such as frailty in old age. The objective of this study was to investigate the association between plasma adiponectin and insulin resistance using the homeostasis model assessment for insulin resistance (HOMA-IR) classified by age. In particular, we sought to determine the factors of the subjects associated with both high adiponectin levels and HOMA-IR (H-adiponectin/H-HOMA) and high adiponectin levels and low HOMA-IR (H-adiponectin/L-HOMA).

METHODS

The eligible subjects in this cross-sectional study were 33,216 individuals who had undergone health checkups at the Physical Checkup Center of Sumitomo Hospital between April 2008 and December 2018. After excluding 26,371 individuals who were under 60 years old, 529 who had been taking medications for diabetes mellitus, and 690 with missing data, the present study included 5,673 (3,467 males, 2,206 females) subjects with no missing data. The relationship between serum adiponectin levels and HOMA-IR was assessed using logistic regression models adjusted by clinically relevant factors.

RESULTS

In the multivariable logistic regression analysis, age and low BMI were shown to positively correlate with the characteristics of H-adiponectin/H-HOMA. In females, systolic blood pressure was also shown to be an associated factor.

CONCLUSION

In conclusion, this study showed that aging or a low BMI may contribute to high adiponectin levels and insulin resistance.

Adipokines and Arterial Stiffness in the Elderly

INTRODUCTION

The aim of this study was to evaluate the relationship between adipokines and arterial stiffness in a group of 85 elderly subjects and the role of leptin and adiponectin on subclinical vascular damage, defined by a PWV>10 m/s.

METHODS

In each subject, we evaluated anthropometry, body composition by DXA (fat mass, fat mass%, lean mass), metabolic variables, leptin, adiponectin, systolic, diastolic, mean arterial pressure and pulse pressure (SBP, DBP, MAP, PP), carotid-femoral pulse wave velocity (cfPWV) and carotid-radial pulse wave velocity (crPWV).

RESULTS

In the study population, significant associations were observed between cfPWV and crPWV, age, SBP, MAP, waist circumference, fat body mass and leptin. The study population was subdivided in 2 subgroups according to adipokine patterns: group 1 included patients with high adiponectin and low leptin, and group 2 patients had high leptin and low adiponectin. SBP, PP, cfPWV were significantly higher in subjects with high leptin and low adiponectin (group 2). Even after adjustment for gender, fat mass%, MAP, HDL cholesterol and triglycerides, cfPWV was higher in group 2 than group 1. In a logistic binary regression on the entire population, considering subclinical vascular damage as a dependent variable and age, gender, MAP, fat mass%, triglycerides, HDL cholesterol and category of subjects with high leptin and low adiponectin as independent variables, MAP and category of subjects with high leptin and low adiponectin were significant predictors (OR, respectively, 1.09 and 3.61).

CONCLUSION

In conclusion, in the elderly, the presence at the same time of high leptin levels and low adiponectin levels seems to have synergic effects on arterial stiffness.

Chronic Kidney Disease Modifies The Relationship Between Body Fat Distribution and Blood Pressure: A Cross-Sectional Analysis

Introduction

Measures of adiposity are related to cardiovascular disease risk, but this relationship is inconsistent in disease states, such as chronic kidney disease (CKD). This study investigated the relationship between adiposity and blood pressure (BP) by CKD status.

Materials and Methods

South Africans of mixed-ancestry (n=1,621) were included. Estimated glomerular filtration rate (eGFR) was based on the modification of diet in renal disease (MDRD) equation, and CKD defined as eGFR <60mL/min/1.73m². Body fat distribution was assessed using anthropometry [body mass index (BMI) and waist circumference (WC)] and dual-energy x-ray absorptiometry (DXA) (n=152). Pulse pressure (PP) and mean arterial pressure (MAP) were calculated from systolic blood pressure (SBP) and diastolic blood pressure (DBP).

Results

In participants without CKD, anthropometric and DXA-derived measures positively correlated with SBP, DBP, MAP and PP (p<0.02 for all), except for leg fat mass (LFM), which was not associated with BP indices (p>0.100 for all). Contrary, in prevalent CKD (6%, n=96), only BMI was inversely associated with PP (p=0.0349). In multivariable analysis, only BMI and WC remained independently associated with SBP, DBP and MAP in the overall sample. Notably, the association between BMI, WC and LFM with SBP and PP, differed by CKD status (interaction: p<0.100 for all), such that only BMI and WC were associated with SBP in those without CKD and inversely associated with PP in those with CKD. LFM was inversely associated with SBP and PP in those with CKD.

Conclusion

In people without CKD, BP generally increases with increasing measures of adiposity. However, excess body fat has a seemingly protective or neutral effect on BP in people with CKD.

Relationship between BMI and aortic stiffness: influence of anthropometric indices in hypertensive men and women

BACKGROUND

Increased aortic stiffness could be one of the mechanisms by which obesity increases cardiovascular risk independently of traditional risk factors. Studies have suggested that anthropometric indices may be predictors of cardiovascular risk but few studies have investigated their relations with aortic stiffness in high cardiovascular risk population. We investigated the strength of correlation between different anthropometric indices with aortic stiffness in hypertensive and diabetic patients.

METHODS

A cross-sectional study was performed in 474 hypertensive patients. Anthropometric indices were calculated: BMI, waist circumference, waist-hip ratio, and waist-height ratio (WHtR). Aortic stiffness was assessed by measurement of carotid-femoral pulse wave velocity (PWV). Correlations between indices and PWV were investigated by linear regression analyses and hierarchical analyses after adjusting for cardiovascular risk factors.

RESULTS

Regional anthropometric indices were more strongly correlated with PWV than BMI in both sexes. In linear regression analyses, WHtR presented the highest correlation with PWV than other indices in our study population. In adjusted hierarchical regression used, WHtR had the highest additive value on top of BMI while there no additive value of BMI on top of WHtR. These differences remained after adjustment on cardiovascular events. In men WHtR was more closely correlated with PWV than others. In women, waist-hip ratio and WHtR were equally correlated with PWV compared with BMI.

CONCLUSION

Regional anthropometric indices are more closely correlated with PWV than BMI in hypertensive patients. WHtR presents the highest correlation with PWV beyond BMI.

REGISTRATION

The study was registered in the French National Agency for Medicines and Health Products Safety (No. 2013-A00227-38) and was approved by the Advisory Committee for Protection of Persons in Biomedical Research.

Lower Leg Fat Depots Are Associated with Albuminuria Independently of Obesity, Insulin Resistance, and Metabolic Syndrome (Korea National Health and Nutrition Examination Surveys 2008 to 2011)

BACKGROUND

Although the involvement of obesity in metabolic disorders is well known, leg fat depot influences on albuminuria have not been determined.

METHODS

This population-based, cross-sectional study used a nationally representative sample of 2,076 subjects aged ≥20 years from the Korea National Health and Nutrition Examination Surveys of 2008 to 2011. The ratio of leg fat to total fat (LF/TF ratio) was assessed by dual X-ray absorptiometry, and albuminuria was defined as more than one positive dipstick test or an albumin-to-creatinine ratio of ≥30 mg/g.

RESULTS

Individuals whose LF/TF ratio was in the lowest tertile showed a higher proportion of albuminuria than those in the highest tertile (odds ratio [OR], 2.82; 95% confidence interval [CI], 2.01 to 3.96; P<0.001). This association was observed in both sexes, all age groups, and all subgroups stratified by body mass index, waist circumference, homeostasis model assessments of insulin resistance, and the presence of metabolic syndrome (all, P<0.05). Multiple logistic regression analyses also demonstrated that the lowest LF/TF ratio was independently associated with albuminuria risk (OR, 1.55 to 2.16; all, P<0.05). In addition, the risk of albuminuria was higher in sarcopenic individuals with lower LF/TF ratios than in the highest LF/TF ratio subjects without sarcopenia (OR, 3.73; 95% CI, 2.26 to 6.13).

CONCLUSION

A lower LF/TF ratio was associated with an increased risk of albuminuria independent of obesity, insulin resistance, and metabolic syndrome, and when combined with sarcopenia, the albuminuria risk synergistically increased. Hence, our findings may have implications to improve risk stratification and recommendations on body fat distribution in the general population.

Obesity-induced hypoadiponectinaemia: the opposite influences of central and peripheral fat compartments

Background and Aims

The substantial reduction in adiponectin concentration among obese individuals seems to depend on fat distribution and is a marker of metabolic and adipose tissue dysfunction. We aimed to: (i) address whether abdominal fat from different compartments (visceral, deep subcutaneous abdominal and superficial subcutaneous abdominal) and gluteofemoral fat are independently associated with blood adiponectin concentration; and (ii) investigate whether abdominal (proxied by waist circumference) and gluteofemoral fat (proxied by hip circumference) accumulation causally determine blood adiponectin concentration.

Methods

To investigate the independent association of abdominal and gluteofemoral fat with adiponectin concentration, we used multivariable regression and data from 30-year-old adults from the 1982 Pelotas Birth Cohort (n = 2,743). To assess the causal role of abdominal and gluteofemoral fat accumulation on adiponectin concentration, we used Mendelian randomization and data from two consortia of genome-wide association studies-the GIANT (n > 210 000) and ADIPOGen consortia (n = 29 347).

Results

In the multivariable regression analysis, all abdominal fat depots were negatively associated with adiponectin concentration, specially visceral abdominal fat [men: β = -0.24 standard unit of log adiponectin per standard unit increase in abdominal fat; 95% confidence interval (CI) = -0.31, -0.18; P = 8*10-13; women: β = -0.31; 95% CI = -0.36, -0.25; P = 7*10-27), whereas gluteofemoral fat was positively associated with adiponectin concentration (men: β = 0.13 standard unit of log adiponectin per standard unit increase in gluteofemoral fat; 95% CI = 0.03, 0.22; P = 0.008; women: β = 0.24; 95% CI = 0.17, 0.31; P = 7*10-11). In the Mendelian randomization analysis, genetically-predicted waist circumference was inversely related to blood adiponectin concentration (β = -0.27 standard unit of log adiponectin per standard unit increase in waist circumference; 95% CI = -0.36, -0.19; P = 2*10-11), whereas genetically-predicted hip circumference was positively associated with blood adiponectin concentration (β = 0.17 standard unit of log adiponectin per standard unit increase in hip circumference; 95% CI = 0.11, 0.24; P = 1*10-7).

Conclusions

These results support the hypotheses that there is a complex interplay between body fat distribution and circulating adiponectin concentration, and that whereas obesity-induced hypoadiponectinaemia seems to be primarily attributed to abdominal fat accumulation, gluteofemoral fat accumulation is likely to exert a protective effect.

Relationships between adiponectin levels, the metabolic syndrome, and type 2 diabetes: a literature review

Elevated hepatic glucose production, impaired insulin secretion, and insulin resistance - abnormalities of glucose metabolism typically found in subjects with obesity - are major factors underlying the pathogenesis of type 2 diabetes (DM2) and the metabolic syndrome (MS). Adiponectin is a major regulator of glucose and lipid homeostasis via its insulin-sensitizing properties, and lower levels seems to be associated with the development of DM2 and MS. The purpose of this review is to clarify the mechanisms whereby adiponectin relates to the development of DM2 and MS and the association between polymorphisms of the adiponectin gene, circulating levels of the hormone, and its relationships with DM2. In addition, the impact of dietary lipids in the circulating levels of adiponectin will be addressed. According to the literature, circulating adiponectin levels seem to decrease as the number of MS components increases. Lower adiponectin concentrations are associated with higher intra-abdominal fat content. Therefore, adiponectin could link intra-abdominal fat with insulin resistance and development of MS. Therapeutic strategies that target the MS and its components, such as lifestyle modification through physical activity and weight loss, have been shown to increase adiponectin concentrations. Possible roles of diets containing either low or high amounts of fat, or different types of fat, have been analyzed in several studies, with heterogeneous results. Supplementation with n-3 PUFA modestly increases adiponectin levels, whereas conjugated linoleic acid supplementation appears to reduce concentrations when compared with unsaturated fatty acid supplementation used as an active placebo.

Obesity and inflammation: the linking mechanism and the complications

Obesity is the accumulation of abnormal or excessive fat that may interfere with the maintenance of an optimal state of health. The excess of macronutrients in the adipose tissues stimulates them to release inflammatory mediators such as tumor necrosis factor α and interleukin 6, and reduces production of adiponectin, predisposing to a pro-inflammatory state and oxidative stress. The increased level of interleukin 6 stimulates the liver to synthesize and secrete C-reactive protein. As a risk factor, inflammation is an imbedded mechanism of developed cardiovascular diseases including coagulation, atherosclerosis, metabolic syndrome, insulin resistance, and diabetes mellitus. It is also associated with development of non-cardiovascular diseases such as psoriasis, depression, cancer, and renal diseases. On the other hand, a reduced level of adiponectin, a significant predictor of cardiovascular mortality, is associated with impaired fasting glucose, leading to type-2 diabetes development, metabolic abnormalities, coronary artery calcification, and stroke. Finally, managing obesity can help reduce the risks of cardiovascular diseases and poor outcome via inhibiting inflammatory mechanisms.

Anatomic fat depots and cardiovascular risk: a focus on the leg fat using nationwide surveys (KNHANES 2008-2011)

BACKGROUND

Although central fat is a well-known risk factor for cardiovascular disease (CVD) and cardiometabolic disorders, the effect of other regional fats or muscle distribution on CVD risk has not been fully investigated.

METHODS

This was a cross-sectional study using nationally representative samples of 15,686 subjects from the 2008-2011 Korea National Health and Nutrition Examination Survey. Individual CVD risk was evaluated in adults aged ≥20 without prior CVD, using atherosclerotic cardiovascular disease (ASCVD) risk equations according to the 2013 ACC/AHA guidelines. Body composition was assessed by dual X-ray absorptiometry.

RESULTS

Ratio of leg fat to total fat (LF/TF ratio) was the most predictive for CVD among body fat or muscle distribution parameters (AUC = 0.748, 95% CI 0.741-0.755). ASCVD risk score was gradually increased with decreased LF/TF ratio (P < 0.001), and individuals whose LF/TF ratio in lowest tertile tended to belong to the high-risk (10-year risk >10%) group compared to those in the highest tertile (OR = 6.25, 95% CI 5.60-6.98). Subjects in the lowest tertile showed increased risk of cardiometabolic risk factor components including obesity, hypertension, diabetes, dyslipidemia, chronic kidney disease, and albuminuria (OR range 2.57-11.24, all P < 0.001). In addition, a higher LF/TF ratio was associated with decreased ASCVD risk, even in subjects with multiple CVD risk factors. Multiple logistic regression analyses also demonstrated this association (OR = 1.85, 95% CI 1.36-2.52).

CONCLUSIONS

Among various body composition parameters, LF/TF ratio was superior in predicting higher CVD risk and a higher LF/TF ratio was independently associated with decreased risk of CVD and each cardiometabolic risk factor.

Relationship between Regional Body Fat Distribution and Diabetes Mellitus: 2008 to 2010 Korean National Health and Nutrition Examination Surveys

BACKGROUND

The aim of this study was to investigate the association between regional body fat distribution, especially leg fat mass, and the prevalence of diabetes mellitus (DM) in adult populations.

METHODS

A total of 3,181 men and 3,827 postmenopausal women aged 50 years or older were analyzed based on Korea National Health and Nutrition Examination Surveys (2008 to 2010). Body compositions including muscle mass and regional fat mass were measured using dual-energy X-ray absorptiometry.

RESULTS

The odds ratios (ORs) for DM was higher with increasing truncal fat mass and arm fat mass, while it was lower with increasing leg fat mass. In a partial correlation analysis adjusted for age, leg fat mass was negatively associated with glycosylated hemoglobin in both sexes and fasting glucose in women. Leg fat mass was positively correlated with appendicular skeletal muscle mass and homeostasis model assessment of β cell. In addition, after adjusting for confounding factors, the OR for DM decreased gradually with increasing leg fat mass quartiles in both genders. When we subdivided the participants into four groups based on the median values of leg fat mass and leg muscle mass, higher leg fat mass significantly lowered the risk of DM even though they have smaller leg muscle mass in both genders (P<0.001).

CONCLUSION

The relationship between fat mass and the prevalence of DM is different according to regional body fat distribution. Higher leg fat mass was associated with a lower risk of DM in Korean populations. Maintaining leg fat mass may be important in preventing impaired glucose tolerance.

Single nucleotide polymorphism of adiponectin +276 G/T is associated with the susceptibility to essential hypertension in a Turkish population

BACKGROUND

It is well known that arterial stiffness is associated with hypertension. Recent studies have shown that adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D polymorphisms are likely to be risk factors for arterial stiffness. In this study, we aimed to investigate possible associations between these single-nucleotide polymorphisms (SNPs) and essential hypertension in a Turkish population.

METHODS

The study population consisted of 170 patients who were diagnosed with essential hypertension and 170 sex- and age-matched controls. Genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs were performed using real-time polymerase chain reaction and commercially produced kits.

RESULTS

The percentage of the adiponectin +276 T allele carriers was significantly higher in the patients with hypertension (33%) than in the controls (25%, p < 0.011). Through multiple logistic regression analysis, the adiponectin +276 T allele carrier was found to be associated with an increased risk of hypertension (TT vs. GG and TG: odds ratio = 3.318, p = 0.014, 95% confidence interval: 1.269-8.678). The genotype distributions or allelic frequencies of ACE I/D, AGTR1 A1166C, and eNOS E298D SNPs did not significantly differ between the patients with hypertension and the controls.

CONCLUSION

The present study demonstrated that the adiponectin +276 G/T SNP is likely to be a risk factor for essential hypertension in a Turkish population.

Obesity phenotypes and resorption percentage after breast autologous fat grafting: Rule of low-grade inflammation

Background:

One of the main reasons why the breast fat grafting was questioned is that there may be lipofilling resorption. In the literature, the resorption rate reported over the 1^st year is highly variable (20–90%).

Objective:

The aim of this work was to identify the biochemical and clinical parameters, which increase fat graft maintenance in breast reconstruction.

Materials and Methods:

A sample of 19 patients was treated with fat grafting mixed with platelet-rich plasma. A complete screening of anthropometry, body composition, and blood biochemical parameters was assessed using the standardized equipment. Pre- and post-operative evaluation was performed, which included a complete clinical examination, photographic assessment, nuclear magnetic resonance imaging of the soft tissue, and ultrasound. The follow-up period was 2 years.

Results:

The authors divided the results into two types of patients: “responder” and “not a responder.” In the “responder” group patients with normal weight, gynoid fat distribution, obese, with normal blood biochemical parameters, and atherogenic indices but with high preoperative values of platelet-to-lymphocyte ratio (PLR) (174.49) and neutrophil-lymphocyte ratio (NLR) (2.65) showed a greater increase of fat graft maintenance at 6 and 12 months after the last lipofilling session. In the “not responder group” patients with overweight, android fat distribution, obese, high values of atherogenic indices, but with normal preoperative NLR and PLR ratios showed a lower fat graft maintenance at 6 and 12 months.

Conclusion:

We assume, the problem of fat resorption may be resolved by analysis of body composition and by examine the predictive role of preoperative markers of low-grade inflammation.

GENETIC ASSOCIATION BETWEEN ARTERIAL STIFFNESS-RELATED GENE POLYMORPHISMS IN BRVO AND CRVO PATIENTS IN A TURKISH POPULATION

PURPOSE

To investigate possible associations between five different single-nucleotide polymorphisms, from genes associated with arterial stiffness and branch retinal vein occlusion (BRVO), or central retinal vein occlusion.

METHODS

A total of 187 patients with retinal vein occlusion (133 with BRVO and 54 with central retinal vein occlusion), and 167 controls, were enrolled in this study. All subjects were screened for hypertension, diabetes, smoking status, body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, total cholesterol, and very low-density lipoprotein. The genotyping of adiponectin +276 G/T, ACE I/D, AGTR1 A1166C, eNOS E298D, and p22phox -242 C/T polymorphisms was performed using real-time polymerase chain reaction.

RESULTS

The percentage of the adiponectin +275 T allele carriers was significantly higher in the BRVO patients (37%) than in the controls (23%, P < 0.001). Similarly, the percentage of AGTR1 1166 C allele carriers was significantly higher in the BRVO patients (38%) than in the controls (24%, P < 0.001). At the multiple logistic regression analysis, the adiponectin +275 T allele carrier and AGTR1 1166 C allele carrier status were found to be associated with an increased risk of BRVO (TT vs. GG and TG: odds ratio = 2.278, P = 0.002, 95% confidence interval: 1.370-3.789; CC vs. AA and AC: odds ratio = 1.804, P = 0.025, 95% confidence interval: 1.079-3.017). The genotype distributions or allelic frequencies of ACE I/D, eNOS E298D, and p22phox -242 C/T did not significantly differ between the patients with BRVO and the control subjects. There was no significant difference between the central retinal vein occlusion patients and controls for the genotype or the allele frequency distributions of all evaluated single-nucleotide polymorphisms.

CONCLUSION

Adiponectin +276 G/T and AGTR1 A1166C single-nucleotide polymorphism are likely to be risk factors for BRVO.

An update on the role of adipokines in arterial stiffness and hypertension

Adipokines are hormones produced by adipocytes and have been involved in multiple pathologic pathways, including inflammatory and cardiovascular complications in essential hypertension. Arterial stiffness is a frequent vascular complication that represents increased cardiovascular risk in hypertensive patients. Adipokines, such as adiponectin, leptin and resistin, might be implicated in hypertension, as well as in vascular alterations associated with this condition. Arterial stiffness has proven to be a predictor of cardiovascular events. Obesity and target-organ damage such as arterial stiffness are features associated with hypertension. This review aims to update the association between adipokines and arterial stiffness in essential and resistant hypertension (RHTN).

Visceral Adiposity is Preferentially Associated with Vascular Stiffness Rather than Thickness in Men with Type 2 Diabetes

Aim: Visceral fat accumulation is known to underlie the clustering of cardiovascular risk factors. However, it is not completely understood how visceral fat accumulation influences the development of cardiovascular disease. In this study, we investigated the clinical impact of visceral adiposity on vascular stiffness and thickness in patients with type 2 diabetes (T2D).

Methods: One hundred and sixty-one patients with T2D, including 92 men and 69 women, were included in this cross-sectional study. Visceral fat area (VFA) and subcutaneous fat area (SFA) were measured by dual bioelectrical impedance analysis. Stiffness parameter β and intima-media thickness (IMT) of the common carotid artery were measured by ultrasonography.

Results: The mean age and duration of diabetes in the study population were 61 years and 13.9 years, respectively. In men, VFA and waist circumference (WC) were positively correlated with stiffness parameter β, whereas body mass index (BMI), WC, and SFA were negatively correlated with IMT. In contrast, in women, none of the obesity-related indices were significantly correlated with stiffness parameter β or IMT. In multiple regression analyses, VFA as well as WC, BMI, and SFA were independently associated with stiffness parameter β after adjustment for age and other potential confounders in men but not in women. None of the obesity-related indices were independently associated with IMT for either sex.

Conclusion: In men with T2D, visceral adiposity is associated with carotid arterial stiffness but not thickness.

Adipokines, cytokines and body fat stores in hepatitis C virus liver steatosis

AIM: To identify patients with or without liver steatosis and its severity in treatment-naïve patients affected by hepatitis C virus (HCV) infection.

METHODS: We included 56 HCV infected patients, and assessed the amount of liver fat by histomorphometry, and its relationships with fat and lean mass at different parts of the body (by densitometry), hormones [insulin, homeostatic model assessment (HOMA)], adipokines (resistin, adiponectin, leptin), and cytokines (tumor necrosis factor α, interleukin-6).

RESULTS: Although the intensity of liver steatosis is related to trunk fat mass and HOMA, 33% of patients showed no liver steatosis, and this finding was not related to body mass index or genotype. Besides trunk fat mass, no other factor was related to the presence or not of liver steatosis, or to the intensity of it, by multivariate analysis. Lean mass was not related to liver steatosis. Adiponectin levels were lower among patients. No differences were observed in leptin and resistin.

CONCLUSION: Steatosis in HCV infection is common (67.2%), and closely related to trunk fat, and insulin resistance, but not with leg fat mass or adipokines.

Specific characterization of regional storage fat in upper and lower limbs of young healthy adults

This study aimed to determine the specific characterization of regional storage fat in the upper limb as compared to the lower limb of young healthy adults. The regional storage fat and skeletal muscle in upper and lower limbs were obtained by magnetic resonance imaging (MRI) and multifrequency bioelectrical impedance analysis (BIA). For MRI measurements, images at the continuous anatomical cross-sectional areas of subcutaneous adipose tissue and skeletal muscle in the upper arm and thigh were selected for the analysis. Values measured by MRI were larger than those measured by BIA. MRI data showed that the percentage of fat was significantly higher in the upper arm compared to the thigh in both men and women. This study suggests that BIA results in a significantly different estimation of the whole body and limb composition when compared to MRI and that MRI is useful to determine regional specificities in the limb composition. From these quantified evaluation, we found significantly large amount of regional storage fat in upper limbs of young healthy adults, especially women.

Liver steatosis in hepatitis C patients

There is controversy regarding some aspects of hepatitis C virus (HCV) infection-associated liver steatosis, and their relationship with body fat stores. It has classically been found that HCV, especially genotype 3, exerts direct metabolic effects which lead to liver steatosis. This supports the existence of a so called viral steatosis and a metabolic steatosis, which would affect HCV patients who are also obese or diabetics. In fact, several genotypes exert metabolic effects which overlap with some of those observed in the metabolic syndrome. In this review we will analyse the pathogenic pathways involved in the development of steatosis in HCV patients. Several cytokines and adipokines also become activated and are involved in “pure” steatosic effects, in addition to inflammation. They are probably responsible for the evolution of simple steatosis to steatohepatitis, making it difficult to explain why such alterations only affect a proportion of steatosic patients.

Arterial stiffness is associated with adipokine dysregulation in non-hypertensive obese mice

The aim of this study was to characterize alterations in vascular structure and mechanics in murine mesenteric arteries from obese non-hypertensive mice, as well as their relationship with adipokines. Four-week old C57BL/6J male mice were assigned either to a control (C, 10% kcal from fat) or a high-fat diet (HFD, 45% kcal from fat) for 32weeks. HFD animals weighed 30% more than controls (p<0.001), exhibited similar blood pressure, increased leptin, insulin and superoxide anion (O2(-)) levels, and reduced adiponectin levels and nitric oxide (NO) bioavailability. Arterial structure showed an outward remodeling with an increase in total number of both adventitial and smooth muscle cells in HFD. Moreover, HFD mice exhibited an increased arterial stiffness assessed by β-values (C=2.4±0.5 vs HFD=5.3±0.8; p<0.05) and aortic pulse wave velocity (PWV, C=3.4±0.1 vs HFD=3.9±0.1; p<0.05). β-Values and PWV positively correlated with leptin, insulin or O2(-) levels, whereas they negatively correlated with adiponectin levels and NO bioavailability (p<0.01). A reduction in fenestrae number together with an increase in type-I collagen amount (p<0.05) were observed in HFD. These data demonstrate that HFD accounts for the development of vascular remodeling and arterial stiffness associated with adipokine dysregulation and oxidative stress, independently of hypertension development.

Influence of body fatness distribution and total lean mass on aortic stiffness in nonobese individuals

BACKGROUND

Subjects with normal body mass index but high body fat percentage have higher cardiovascular risk than subjects with normal weight and low fat mass. However, the association of fat distribution and lean mass with carotid-femoral pulse wave velocity (cfPWV) among nonobese apparently healthy individuals has never been assessed.

METHODS

In 136 nonobese volunteers (mean age = 45±9 years; 57% women) without manifest cardiovascular disease, cfPWV was measured by applanation tonometry. Fat and lean mass were measured by dual-energy x-ray absorptiometry.

RESULTS

In univariate analysis, total fat (r = 0.17; P < 0.01), trunk fat (r = 0.27; P < 0.01), and trunk/total fat ratio (r = 0.32; P < 0.01) were correlated with cfPWV. After adjustment for age and mean arterial pressure, only central fat distribution (trunk/total fat ratio) was significantly associated with cfPWV. In the fully adjustment model, there was a significant interaction between fat distribution and lean mass. When the study sample was grouped by fat distribution and total lean mass medians, subjects with central fat distribution and low lean mass (group 4) had higher log-transformed cfPWV than the noncentral fat/low lean mass group (group 2) (0.89, 95% confidence interval (CI) = 0.86-0.92 vs. 0.85, 95% CI = 0.83-0.87; P < 0.01) or the noncentral fat/high lean mass group (group 1) (0.89, 95% CI = 0.86-0.92 vs. 0.84, 95% CI = 0.81-0.87; P < 0.01) after adjustments. Aortic stiffness increased from group 1 to group 4 (P for linear trend < 0.001).

CONCLUSIONS

Among normal weight individuals without manifest cardiovascular disease, the combination of central fat distribution and low lean mass is associated with higher cfPWV. These factors are more closely related to cfPWV than total fat mass.

High body fat and low muscle mass are associated with increased arterial stiffness in Asian Indians in North India

AIM

To investigate the associations of high body fat and low muscle mass with arterial stiffness in Asian Indians with type 2 diabetes mellitus (T2DM) in North India.

METHODS

In this cross sectional study, subjects with T2DM (males n=110, females n=58, mean age: 53.8±10.0years) were recruited. Anthropometry and body composition analysis were performed and measures of glycemia, lipids and PWV were analyzed.

RESULTS

Significant positive correlation was observed between PWV and body fat (p<0.05), left leg fat (p<0.05), and right leg fat (p<0.01) percentages only in females. In males, significant negative correlation was observed between PWV and truncal fat free mass (p<0.05) and fat free mass in right arm (p=0.05) and left arm (p<0.05). In both males and females, significant negative correlation was observed between PWV and fat free mass in left leg (p<0.01) and for right leg fat free mass only in females.

CONCLUSION

Excess adiposity and low fat free mass are associated with arterial stiffening in Asian Indians with T2DM in North India, with significant gender differences.

Association between Appendicular Fat Mass and Metabolic Risk Factors

BACKGROUND

Different regional fat depots have different effects on lipid and glucose metabolism. The purpose of this study is to examine the relationship between body fat distribution as measured by dual-energy X-ray absorptiometry (DEXA) and metabolic risk factors and to disclose whether there is any difference between groups with and without metabolic syndrome (MS).

METHODS

A total of 292 participants (98 men, 194 women) over 19 years old underwent whole-body DEXA to evaluate body composition with respect to the whole body, leg, arm, and android regions. Anthropometry and blood tests for metabolic risks were measured.

RESULTS

One hundred and seven participants were diagnosed with MS. The MS group had significantly higher android fat (%) and had lower leg fat (%), arm fat (%), and appendicular (arms + legs) fat (%) than the non-MS group. Android fat (%) had a positive correlation with waist circumference (WC), systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, log insulin, hemoglobin A1c (HbA1c), triglyceride (TG), and low density lipoprotein cholesterol, and had a negative correlation with high density lipoprotein (HDL) cholesterol. Appendicular fat (%) had a negative correlation with WC, SBP, DBP, glucose, log insulin, HbA1c, and TG, and had a positive correlation with HDL cholesterol. The association of appendicular fat with metabolic risk was consistently observed in non-MS, but the association was not observed except for SBP, glucose and log insulin in MS.

CONCLUSION

In contrast with the adverse effects of android fat, appendicular fat distribution was associated with decreased risks of MS. The protective effect of appendicular fat against metabolic risk factors in non-MS was less characteristic in MS.

Lipid accumulation in overweight type 2 diabetic subjects: relationships with insulin sensitivity and adipokines

Adipokines are known to play a fundamental role in the etiology of obesity, that is, in the impaired balance between increased feeding and decreased energy expenditure. While the adipokine-induced changes of insulin resistance in obese diabetic and nondiabetic subjects are well known, the possible role of fat source in modulating insulin sensitivity (IS) remains controversial. The aim of our study was to explore in overweight type 2 diabetic patients (T2DM) with metabolic syndrome IS in different energy storage conditions (basal and dynamic) for relating it to leptin and adiponectin. Sixteen T2DM (5/11 F/M; 59 ± 2 years; 29.5 ± 1.1 kg/m(2)) and 16 control (CNT 5/11; 54 ± 2; 29.1 ± 1.0) underwent an oral glucose tolerance test. Fasting IS was measured by QUICKI, while the dynamic one with OGIS. The insulinogenic index (IGI) described beta cell function. Also, the lipid accumulation product parameter (LAP) was assessed. LAP accounts for visceral abdominal fat and triglycerides, and it is known to be related to IS. Possible interrelationships between LAP and adipokines were explored. In T2DM and CNT, adiponectin (7.4 ± 0.5 vs. 7.8 ± 0.9 μg/mL), leptin (13.3 ± 3.0 vs. 12.4 ± 2.6 ng/mL), and QUICKI (0.33 ± 0.01 vs. 0.33 ± 0.01) were not different (P > 0.40), at variance with OGIS (317 ± 11 vs. 406 ± 13 mL/min/m(2); P = 0.006) and IGI (0.029 ± 0.005 vs. 0.185 ± 0.029 × 10(3) pmolI/mmolG; P = 0.00001). LAP was 85 ± 15 cm × mg/dL in T2DM and 74 ± 10 in CNT (P > 0.1), correlated with OGIS in all subjects (R = -0.42, P = 0.02) and QUICKI (R = -0.56, P = 0.025) in T2DM. Leptin correlated with QUICKI (R = -0.45, P = 0.009), and adiponectin correlated with OGIS (R = 0.43, P = 0.015). In overweight T2DM, insulin sensitivity in basal condition appears to be multifaceted with respect to the dynamic one, because it should be more fat-related. Insulin sensitivity appears to be incompletely described by functions of fasting glucose and insulin values alone and the use of other indices, such as LAP could be suggested.

Sex dimorphism and depot differences in adipose tissue function

Obesity, characterized by excessive adiposity, is a risk factor for many metabolic pathologies, such as type 2 diabetes mellitus (T2DM). Numerous studies have shown that adipose tissue distribution may be a greater predictor of metabolic health. Upper-body fat (visceral and subcutaneous abdominal) is commonly associated with the unfavorable complications of obesity, while lower-body fat (gluteal-femoral) may be protective. Current research investigations are focused on analyzing the metabolic properties of adipose tissue, in order to better understand the mechanisms that regulate fat distribution in both men and women. This review will highlight the adipose tissue depot- and sex-dependent differences in white adipose tissue function, including adipogenesis, adipose tissue developmental patterning, the storage and release of fatty acids, and secretory function. This article is part of a Special Issue entitled: Modulation of Adipose Tissue in Health and Disease.

Central and peripheral fat and subclinical vascular damage in older women

OBJECTIVE

the aim of this study was to evaluate the relationship between fat distribution and arterial compliance in a group of elderly women, in particular to test a possible independent role of abdominal fat mass and peripheral fat mass on subclinical vascular damage, defined by a pulse wave velocity (PWV) >12 m/s.

METHODS

in 96 women with age range 60-80 years (68.65 ± 4.98 years) and BMI range from 18.8 to 41.2 kg/m(2) (27.07 ± 4.61 kg/m(2)), we evaluated the body mass index, waist circumference, systolic and diastolic blood pressure, fasting glucose, cholesterol, LDL and HDL cholesterol, triglycerides and body composition by dual energy X-ray absorptiometry (DXA). Arterial stiffness was assessed by carotid-femoral (PWVcf) and carotid-radial pulse wave velocity (PWVcr).

RESULTS

significant associations were found between PWVcf, age, waist circumference, BMI and trunk fat assessed by DXA, as well as TG and HDL cholesterol. After adjustment for the total fat mass a negative statistically significant association between PWVcf and leg fat mass was shown. In multiple regression analyses the mean arterial pressure, trunk fat mass and leg fat mass were significant predictors of vascular damage with OR, respectively, of 1.06 (CI: 1.01-1.11), 1.25 (CI: 1.06-1.48) and 0.73 (CI: 0.53-0.99).

CONCLUSIONS

the results of this study show, in a sample of apparently healthy elderly women, that central and peripheral adiposity are independent predictors, with an opposite effect on subclinical vascular damage, confirming and strengthening the protective role of the gluteal-femoral fat on cardiovascular risk even in elderly.

Associations between trunk, leg and total body adiposity with arterial stiffness

BACKGROUND

Obesity and arterial stiffness are associated, but fat distribution patterns may be more strongly related to arterial stiffness than general obesity because of the possible increased inflammation associated with increased abdominal adiposity. The aims of this study were to examine whether fat patterning is associated with arterial stiffness, and determine whether these associations are mediated by low-grade inflammation.

METHODS

Adult participants from the Fels Longitudinal Study (228 males and 254 females) were assessed for brachial-ankle pulse wave velocity (BaPWV) to determine arterial stiffness. Dual energy X-ray absorptiometry was used to estimate fat percentage of the trunk and legs (e.g., TRUNKFAT% and LEGFAT%). High-sensitivity C-reactive protein (hs-CRP) levels were assayed as a general marker of inflammation. General linear regression analyses were used.

RESULTS

BaPWV was positively associated with TRUNKFAT% (r = 0.44 in men and r = 0.38 in women), whereas it was inversely related to LEGFAT% (r = -0.40 in men and r = -0.39 in women). In multiple regression analyses, each SD increase in TRUNKFAT% was associated with an ~1.03 m/s increase in BaPWV in both men and women. Each SD increase in LEGFAT% was related to a similar magnitude of decrease (1.03 m/s) in BaPWV in both sexes. The relationships of TRUNKFAT% and LEGFAT% with BaPWV were attenuated slightly when including hs-CRP in the models, but remained significant.

CONCLUSIONS

We found that trunk and leg fat are related to BaPWV in opposite directions when total body adiposity was accounted for. However, the associations between regional fat patterning and arterial stiffness did not appear to be mediated by low-grade inflammation.

Fatty acids impair endothelium-dependent vasorelaxation: a link between obesity and arterial stiffness in very old Zucker rats

To analyze age-related interactions between obesity, its associated metabolic disorders, and macrocirculation, we studied large artery stiffness and fatty acid responsiveness in lean and obese Zucker rats, aged 25 (adult) and 80 weeks (very old). Systolic arterial pressure was higher in old obese than in old lean rats (178 ± 10 vs 134 ± 8 mmHg, respectively). Carotid elastic modulus-wall stress curves showed increased age-dependent arterial stiffening, which was greater in obese animals. Old obese exhibited endothelial dysfunction with increased systemic oxidative stress. Adult obese had elevated plasma free fatty acid levels (1,866 ± 177 vs 310 ± 34 μg/μL in lean animals). In old obese, linoleate and palmitate increased contractility to phenylephrine and reduced relaxation to acetylcholine. Thus, obesity at 25 weeks appears to trigger accelerated arterial aging observed at 80 weeks. The early increase in free fatty acids may be a key effector in the severe arterial stiffness of the aged obese Zucker model.

Impact of age on leptin and adiponectin independent of adiposity

Age-related changes in leptin and adiponectin levels remain controversial, being affected by inconsistent normalisation for adiposity and body fat distribution in the literature. In a cross-sectional study on 210 Caucasians (127 women, eighty-three men, 18-78 years, BMI 16.8-46.8 kg/m²), we investigated the effect of age on adipokine levels independent of fat mass (FM measured by densitometry), visceral and subcutaneous adipose tissue volumes (VAT and SAT assessed by whole-body MRI). Adiponectin levels increased with age in both sexes, whereas leptin levels decreased with age in women only. There was an age-related increase in VAT (as a percentage of total adipose tissue, VAT%TAT), associated with a decrease in SAT(legs)%TAT. Adiposity was the main predictor of leptin levels, with 75.1 % of the variance explained by %FM in women and 76.6 % in men. Independent of adiposity, age had a minor contribution to the variance in leptin levels (5.2 % in women only). The variance in adiponectin levels explained by age was 14.1 % in women and 5.1 % in men. In addition, independent and inverse contributions to the variance in adiponectin levels were found for truncal SAT (explaining additional 3.0 % in women and 9.1 % in men) and VAT%TAT (explaining additional 13.0 % in men). In conclusion, age-related changes in leptin and adiponectin levels are opposite to each other and partly independent of adiposity and body fat distribution. Normalisation for adiposity but not for body fat distribution is required for leptin. Adiponectin levels are adversely affected by subcutaneous and visceral trunk fat.

Adipose tissue mass and location affect circulating adiponectin levels

AIMS/HYPOTHESIS

Plasma levels of adiponectin are inversely associated with body mass. We hypothesised that adipose tissue distribution and body composition influences adiponectin levels.

METHODS

We assessed plasma adiponectin concentrations and dual-energy X-ray absorptiometry (DEXA) measurements of body composition among 2,820 participants from the Dallas Heart Study.

RESULTS

Among both women and men, adiponectin levels were higher in whites than in either Hispanics or African-Americans (for women: median 9.99 μg/ml [25th,75th percentile 7.11, 13.77] vs 7.56 μg/ml [5.05, 9.98] vs 6.39 μg/ml [4.37, 9.41], respectively, p < 0.0001; for men: 6.43 μg/ml [4.66, 9.19] vs 5.55 μg/ml [3.64, 7.50] vs 5.03 μg/ml [3.39, 7.28], p < 0.0001). In univariate analysis, each individual component of body mass was inversely associated with adiponectin. After multivariate analysis, adiponectin levels were found to be positively associated with lower extremity fat, whether expressed in absolute mass (for women: β = 0.055, p < 0.0001; for men: β = 0.061, p < 0.0001), or as a relative proportion (for women: β = 0.035, p < 0.0001; for men: β = 0.034, p < 0.0001). This association was consistent across ethnicities. Conversely, adiponectin was negatively correlated with truncal fat, both in absolute (for women: β = -0.039, p < 0.0001; for men: β = -0.044, p < 0.0001) and relative terms (for women: β = -0.027, p < 0.0001; for men β = -0.033, p < 0.0001). At the extreme of body mass, higher degrees of lower extremity and truncal adiposity were associated with higher levels of adiponectin.

CONCLUSIONS/INTERPRETATION

These data suggest that the location of adipose depots differentially influences circulating adiponectin concentrations-a finding observed across ethnicity and sex. Gross measures of body mass alone do not adequately account for adiponectin levels. This supports a role of adiponectin as a mediator of the positive effects of lower extremity adiposity on improvements in insulin sensitivity.

Increases in central fat mass and decreases in peripheral fat mass are associated with accelerated arterial stiffening in healthy adults: the Amsterdam Growth and Health Longitudinal Study

BACKGROUND

Central fatness is associated with higher arterial stiffness, a mechanism that may explain adiposity-related increases in cardiovascular disease risk. In contrast, peripheral fat and lean masses may counteract such adverse effects, but evidence of this contention, as derived from longitudinal studies at the general population level, is lacking.

OBJECTIVE

The objective was to investigate the associations between changes in central (ie, trunk) fat mass, peripheral (ie, limbs) fat mass, and lean masses with changes in arterial stiffness.

DESIGN

A longitudinal study in 277 (145 women) healthy adults was conducted. Body composition (dual-energy X-ray absorptiometry) and arterial stiffness estimates (ultrasound imaging) were measured repeatedly at the ages of 36 and 42 y.

RESULTS

Changes (per 10 kg) in trunk fat mass were positively associated and changes in peripheral fat mass were inversely associated with carotid Young's elastic modulus (in 10(3) ⋅ kPa) [β = 0.14 (95% CI: 0.02, 0.25) and -0.16 (-0.30, -0.01), respectively] and carotid-femoral pulse wave velocity (in m/s) [β = 1.54 (0.02, 3.07) and -1.46 (-3.48, 0.56), respectively]. Individuals in whom trunk fat increased and peripheral fat decreased over the 6-y follow-up (33% of the study population) had the steepest increases in these stiffness estimates. Notably, these changes were accompanied by minor increases in body weight, which remained within the limits of the normal range throughout.

CONCLUSIONS

Increases in trunk mass and decreases in peripheral fat mass are associated with accelerated arterial stiffening. These findings emphasize the importance of assessing regional changes in body composition, because it may enable identification of individuals with an unrecognized increased cardiovascular disease risk.

Regional adiposity and risk for coronary artery disease in type 1 diabetes: does having greater amounts of gluteal-femoral adiposity lower the risk?

AIMS

Evidence suggests that the degree of gluteal-femoral adiposity may be inversely associated with coronary artery disease (CAD) risk; however, this association has not been evaluated in type 1 diabetes (T1D).

METHODS

The relationship between regional adiposity, cardiovascular risk factors, and presence of CAD was examined in participants from the Pittsburgh Epidemiology of Diabetes Complications (EDC) study using data collected from the 18-year exam (n=163). Total and regional adiposity was assessed by dual X-ray absorptiometry (DEXA).

RESULTS

Participants with CAD exhibited lower % leg fat mass (FM) (33.42 vs. 36.96, p=0.006) and higher % trunk FM (48.33 vs. 45.18, p=0.02), respectively, after adjusting for age, sex, height, and total adiposity compared to those without CAD. Multivariate logistic regression analyses revealed that in females, every 1 SD increase in % leg FM was associated with an approximate 60% reduction in CAD risk (OR=0.40, 95% CI 0.16-0.99). Higher % trunk FM was also associated with greater risk of CAD prevalence in females (OR=2.79, 95% CI 1.08-7.20 per SD change). These associations were not observed in males.

CONCLUSIONS

This is novel evidence that DEXA-assessed lower body adiposity is inversely associated with CAD in T1D, however, this association seems to only exist in females.

Associations of circulating adiponectin with measures of vascular function and morphology

CONTEXT

Some previous studies have reported an association between circulating adiponectin and selected measures of vascular function and morphology, but most of these studies have been performed in small samples of patients with preexisting disease.

OBJECTIVE

We aimed to evaluate associations between circulating adiponectin and comprehensive measures of vascular function and morphology in a large sample of individuals from the community.

DESIGN, SETTINGS, AND PARTICIPANTS

We conducted a cross-sectional investigation of 981 70-yr-old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS).

MAIN OUTCOME MEASURES

Measures of outcome included vascular function [common carotid artery (CCA) distensibility, flow-mediated dilation, endothelium-dependent and endothelium-independent vasodilation using invasive methods] and vascular morphology [intima-media (IM) thickness, plaque presence, gray scale median (GSM) in the IM and plaques].

RESULTS

In age- and sex-adjusted models, adiponectin was positively associated with IM-GSM, plaque GSM, CCA distensibility, endothelium-dependent and endothelium-independent vasodilation. In multivariable models (with additional adjustment for body mass index; systolic blood pressure; antihypertensive, antidiabetic, and lipid-lowering medication; fasting blood glucose; total cholesterol; high-density lipoprotein cholesterol; creatinine; and smoking), adiponectin remained positively associated with IM-GSM [beta = 2.06; 95% confidence interval (CI), 0.54, 3.58], plaque GSM (beta = 3.11; 95% CI, 0.36, 5.86), and CCA distensibility (beta = 0.04; 95% CI, 0.00, 0.07).

CONCLUSIONS

Serum levels of adiponectin were positively associated with IM-GSM and plaque GSM (indicating lower fat content in the IM and plaques) and CCA distensibility (indicating higher wall elasticity), independent of potential confounders. Our results imply that adiponectin is associated with less arterial pathology.

Gluteofemoral body fat as a determinant of metabolic health

Body fat distribution is an important metabolic and cardiovascular risk factor, because the proportion of abdominal to gluteofemoral body fat correlates with obesity-associated diseases and mortality. Here, we review the evidence and possible mechanisms that support a specific protective role of gluteofemoral body fat. Population studies show that an increased gluteofemoral fat mass is independently associated with a protective lipid and glucose profile, as well as a decrease in cardiovascular and metabolic risk. Studies of adipose tissue physiology in vitro and in vivo confirm distinct properties of the gluteofemoral fat depot with regards to lipolysis and fatty acid uptake: in day-to-day metabolism it appears to be more passive than the abdominal depot and it exerts its protective properties by long-term fatty acid storage. Further, a beneficial adipokine profile is associated with gluteofemoral fat. Leptin and adiponectin levels are positively associated with gluteofemoral fat while the level of inflammatory cytokines is negatively associated. Finally, loss of gluteofemoral fat, as observed in Cushing's syndrome and lipodystrophy is associated with an increased metabolic and cardiovascular risk. This underlines gluteofemoral fat's role as a determinant of health by the long-term entrapment of excess fatty acids, thus protecting from the adverse effects associated with ectopic fat deposition.