The adipokine profile of metabolically benign obese and at-risk normal weight postmenopausal women: the Women's Health Initiative Observational Study

Evaluation of the association between circulating IL-1β and other inflammatory cytokines and incident atrial fibrillation in a cohort of postmenopausal women

BACKGROUND

Inflammatory cytokines play a role in atrial fibrillation (AF). Interleukin (IL)-1β, which is targeted in the treatment of ischemic heart disease, has not been well-studied in relation to AF.

METHODS

Postmenopausal women from the Women's Health Initiative were included. Cox proportional hazards regression models were used to evaluate the association between log-transformed baseline cytokine levels and future AF incidence. Models were adjusted for body mass index, age, race, education, hypertension, diabetes, hyperlipidemia, current smoking, and history of coronary heart disease, congestive heart failure, or peripheral artery disease.

RESULTS

Of 16,729 women, 3,943 developed AF over an average of 8.5 years. Racial and ethnic groups included White (77.4%), Black/African-American (16.1%), Asian (2.7%), American Indian/Alaska Native (1.0%), and Hispanic (5.5%). Baseline IL-1β log continuous levels were not significantly associated with incident AF (HR 0.86 per 1 log [pg/mL] increase, P= .24), similar to those of other inflammatory cytokines, IL-7, IL-8, IL-10, IGF-1, and TNF-α. There were significant associations between C-reactive protein (CRP) and IL-6 with incident AF.

CONCLUSIONS

In this large cohort of postmenopausal women, there was no significant association between IL-1β and incident AF, although downstream effectors, CRP and IL-6, were associated with incident AF.

The influence of resistance training on adipokines in post-menopausal women: A brief review

The onset of menopause elicits changes in body composition that negatively influence adipokine levels. Consequently, various health risk factors (e.g., cardiovascular disease, osteoporosis, physical inactivity, obesity, arterial hypertension, hypercholesterolemia, sarcopenia) are influenced by adipokines due to changes in body composition after menopause. Thus, improvements in body composition are considered the primary influencer of adipokines. Though several therapeutic interventions (e.g., medication, diet, meditation, exercise) are employed to target changes in body composition, resistance training appears to be more effective in positively improving body composition through changes in lean-muscle mass/fat-mass ratio. However, due to the lack of research, very little is known about adipokines' anti/inflammatory response in postmenopausal women after completing resistance training. Most resistance training studies in postmenopausal women have focused on leptin, adiponectin, and resistin, with limited research assessing other adipokines that are important in metabolic regulation and inflammatory processes. Additionally, the consistency of resistance training protocols as an intervention is not standardized or fully recognized. Therefore, the focus of this review is to establish a more comprehensive understanding of the benefits of resistance training on influencing adipokine levels based on changes to total body composition in postmenopausal women.

Metabolically healthy obesity: prevalence, phenotype characteristic, effectiveness of weight loss

The goal was to study the prevalence of metabolically healthy obesity (MHO), the features of this phenotype compared with metabolically unhealthy obesity (MUHO), and the effect of weight loss on cardiometabolic risk factors in patients with MHO. Material and Methods — To assess the prevalence of MHO, 389 case histories of obese patients aged 18-60 were analyzed. Three types of MHO criteria were used: 1) the definitions of metabolic syndrome (MS) according to International Diabetes Federation (IDF), 2005; 2) the HOMA-IR index (<2.7); 3) Biobank Standardisation and Harmonisation for Research Excellence in the European Union (BioSHaRE-EU) criteria, 2013. The study included comparative analysis of the medical history, anthropometry, basic metabolic parameters, and adipocytokine levels in 44 patients with MHO (taking into account the MS definitions) and 33 women with MUHO initially and with a decrease in body mass (BM) by ≥5% after 6 months. Results — The MHO prevalence was: according to the definitions of MS – 38.6%, according to HOMA-IR index – 34.5%, in BioSHaRE-EU – 9.6%. All indicators of anthropometry, carbohydrate and lipid metabolism, including the HOMA-IR index, interleukin-6, and chemerin, as well as the duration of obesity in the MHO and MUHO groups significantly differed (p<0.05). After 6 months, MHO-patients who lost ≥5% BM from the initial value (63.6%) showed an increase of adiponectin, a decrease in waist circumference, HOMA-IR index, C-reactive protein (CRP), retinol-binding protein 4 (RBP-4), and chemerin (p<0.05). Conclusion — The MHO prevalence was maximal according to the MS definitions and minimal with BioSHaRE-EU criteria. The BM decrease in MHO is accompanied by a decrease in the content of proinflammatory adipocytokines and the HOMA-IR index, which determines the need to treat obesity regardless of the phenotype.

Participation of white adipose tissue dysfunction on circulating HDL cholesterol and HDL particle size in apparently healthy humans

OBJECTIVE

To use the combined presence of the elevated insulin resistance index in adipose tissue (Adipo-IR) and low values of adiponectin as a marker of dysfunctional adipose tissue, and to analyze its possible association with low values of high-density lipoprotein cholesterol (HDL-C) and small size of HDL particles.

RESEARCH DESIGN AND METHODS

The analysis included 253 subjects with functional adipose tissue and 253 with dysfunctional adipose tissue, considering similar gender, age, and body mass index (BMI). Adipo-IR was considered when index values (free fatty acids × insulin concentrations) were ≥75th percentile. Low levels of adiponectin were considered when concentration in serum was <25th percentile (determined by ELISA). HDL size was estimated by a quantitative validated equation. Small HDL size was considered when values were <25th percentile.

RESULTS

When comparing subjects with functional adipose tissue with those of dysfunctional adipose tissue, the latter had a higher prevalence of low HDL-C (51.4% vs. 64.0%; p = 0.004) and small HDL (56.9% vs. 67.6%; p = 0.009). Multivariate analysis indicated that independently from other metabolic risk factors, dysfunction of adipose tissue is significantly associated with low HDL-C (OR: 1.624 [CI 95%: 1.100-2.397]) and small HDL (OR: 1.462 [CI 95%: 1.000-2.139]). Adding BMI, waist circumference, and subcutaneous or visceral adipose tissue did not modify the association.

CONCLUSIONS

Dysfunction of adipose tissue is associated with a 65 and 50% higher probability of having low HDL-C and small HDL. Identification of dysfunctional adipose tissue could be a useful tool in the clinical setting to prevent the cardiometabolic risk independently from adiposity.

Interrelations Between Inflammatory and Oxidative Stress Biomarkers in Obese Women with Two Complications (Hypertension, Diabetes)

Background and aims: Interaction between oxidative stress and inflammation has not been comprehensively investigated in the association obesity – diabetes - hypertension. Our aim was to investigate interrelations between inflammatory and oxidative stress biomarkers in obese women with two complications (hypertension, type 2 diabetes).

Material and Methods: 54 obese patients without complications, 46 diabetic patients with obesity, 48 hypertensive diabetic obese women, and 120 healthy controls were recruited from the department of nuclear medicine (Algeria). Inflammatory and oxidative stress biomarkers were assayed by appropriate methods.

Results: Inflammatory markers were significantly higher in all obese groups compared to controls. Elevated pro-oxidants and decreased antioxidant markers were noted in obese women. These alterations were accentuated when obesity was associated with hypertension and diabetes. A positive interrelationship between inflammatory mediators and oxidative status, and a negative one with antioxidants were noted during obesity. Hypertension and diabetes enhanced these correlations. Leptin, C-reactive protein, catalase, superoxide dismutase, ion superoxide, peroxynitrite were found to be the best inflammatory and oxidative stress biomarkers that can predict diabetes and hypertension in obese women.

Conclusions: oxidative stress and inflammation were intimately interconnected in women obesity associated with diabetes and hypertension.

Impact of Intensive Lifestyle Modification on Levels of Adipokines and Inflammatory Biomarkers in Metabolically Healthy Obese Women

Background

For the metabolically healthy obese (MHO) subjects, it is unclear whether weight loss provides cardiometabolic benefits. Our objective was to evaluate whether changes in adipokine and inflammatory biomarker levels were related to lifestyle modification (with Mediterranean diet and physical exercise program).

Methods

115 women (35-55 years) with BMI of 30-40 kg/m² and ≤1 metabolic syndrome criteria were included. After a 2-year intervention, participants were classified by percent weight loss: Group 1, <5%; Group 2, ≥5%-<10%; and Group 3, ≥10%. Anthropometric data, inflammatory biomarker (IL-6, TNFa, and hsCRP) and adipokine levels (adiponectin and resistin), and lifestyle program adherence at baseline and 2 years were analyzed.

Results

The final sample comprised 67 women. 23 (38.3%) lost <5%, 22 (36.7%) lost ≥5%-<10%, and 22 (36.7%) lost ≥10% of baseline weight. After 2 years, in Group 1, adiponectin, hsCRP, IL-6, and TNFa decreased (-1.2 ng/ml, p = 0.003; -2.1 mg/l, p = 0.003; -2.4 pg/ml, p < 0.001; and -2.4 pg/ml, p = 0.001, respectively) and resistin increased (+2.4 ng/ml, p < 0.001). In Group 2, hsCRP and IL-6 decreased (-2.0 mg/l, p = 0.009 and -2.6 pg/ml, p = 0.001) but TNFa increased (+0.2 pg/ml, p = 0.02). In Group 3, resistin increased (+3.5 ng/ml, p < 0.001) but hsCRP, IL-6, and TNFa decreased (-2.0 mg/l, p = 0.009; -2.5 pg/ml, p < 0.001; and -4.1 pg/ml, p < 0.001). Adiponectin, hsCRP, and physical exercise correlated significantly to subjects' dietary adherence.

Conclusion

Weight loss reduces inflammatory biomarkers in the MHO but induces a deterioration in the adipokine profile, which does not improve with diet and exercise intervention. These findings allow us to clarify mechanisms behind inflammation and metabolic disorder genesis so as to prevent development of obesity-associated comorbidities.

Heterogeneity of obesity phenotypes in relation to cardiovascular risk

Obesity is associated with numerous metabolic disorders, the development and progression of a wide range of conditions and diseases, primarily cardiovascular disease and type 2 diabetes. One of the widely discussed phenomena of the association of obesity with cardiovascular diseases, their complications and mortality is the phenomenon of “heterogeneity of obesity phenotypes in relation to cardiovascular risk”. Currently, two main phenotypes have been identified — metabolically healthy and metabolically unhealthy obesity. At the same time, not only the expediency of separation, but also the existence of this phenotype is widely discussed today. The article provides an overview of existing approaches to the verification of metabolic phenotypes of obesity and data relating to the epidemiology and the association of metabolically healthy obesity with the risk of cardiovascular diseases and death, and also discusses the factors that determine the features of the obesity phenotype.

Heterogeneity of obesity phenotypes in relation to cardiovascular risk

Obesity is associated with numerous metabolic disorders, the development and progression of a wide range of conditions and diseases, primarily cardiovascular disease and type 2 diabetes. One of the widely discussed phenomena of the association of obesity with cardiovascular diseases, their complications and mortality is the phenomenon of “heterogeneity of obesity phenotypes in relation to cardiovascular risk”. Currently, two main phenotypes have been identified — metabolically healthy and metabolically unhealthy obesity. At the same time, not only the expediency of separation, but also the existence of this phenotype is widely discussed today. The article provides an overview of existing approaches to the verification of metabolic phenotypes of obesity and data relating to the epidemiology and the association of metabolically healthy obesity with the risk of cardiovascular diseases and death, and also discusses the factors that determine the features of the obesity phenotype.

Abdominal obesity phenotypes and incident diabetes over 12 years of follow-up: The Tehran Lipid and glucose study

AIMS

To investigate future diabetes in different abdominal obesity phenotypes during 12 years of follow-up.

METHODS

For this population-based cohort, 7982 adults without diabetes including 3533 men and 4449 women, aged ≥20 years were selected from the Tehran Lipid and Glucose Study. Abdominal obesity was defined according to the national cutoffs for waist circumference (WC). Metabolic health was defined as having ≤1 metabolic abnormality based on Joint Interim Statement (JIS) criteria other than WC. Participants were classified into 4 groups of abdominal obesity phenotypes: Metabolically healthy non-abdominal obese (MHNAO), metabolically healthy abdominal obese (MHAO), metabolically unhealthy non-abdominal Obese (MUNAO), and metabolically unhealthy abdominal obese (MUAO).

RESULTS

In total, 1018 cases of incident diabetes occurred. Compared to the MHNAO phenotype, based on multivariate Cox regression models, diabetes risk was increased in all unhealthy phenotypes except the MUNAO phenotype in men. Regarding the association of the MHAO phenotype with incident diabetes, borderline statistical significance in men [HR 1.5 (95% CI: 1.0-2.36), p-value: 0.07] and statistical significance in women [HR 1.68 (95% CI: 1.08-2.6)] were detected.

CONCLUSIONS

In addition to unhealthy phenotypes except the MUNAO phenotype in men, the MHAO phenotype is also associated with incident diabetes, highlighting the importance of preventive strategies in this subgroup of abdominally obese subjects.

Visceral Adipose Tissue Accumulation and Residual Cardiovascular Risk

PURPOSE OF THE REVIEW

Low-grade systemic inflammation increases residual cardiovascular risk. The pathogenesis of low-grade systemic inflammation is not well understood.

RECENT FINDINGS

Visceral adipose tissue accumulates when the subcutaneous adipose tissue can no longer store excess nutrients. Visceral adipose tissue inflammation initially facilitates storage of nutrients but with time become maladaptive and responsible for low-grade systemic inflammation. Control of low-grade systemic inflammation requires reversal of visceral adipose tissue accumulation with intense and sustained aerobic exercise or bariatric surgery. Alternatively, pharmacologic inhibition of the inflammatory signaling pathway may be considered. Reversal visceral adipose tissue accumulation lowers residual cardiovascular risk.

Cardiometabolic Changes in Different Gonadal Female States Caused by Mild Hyperuricemia and Exposure to a High-Fructose Diet

BACKGROUND

The objective of this study is to observe if mild hyperuricemia and a high-fructose diet influence the cardiovascular and metabolic systems in hypogonadic female Wistar rats compared to normogonadic female rats.

METHODS

Fifty-six (56) adult female Wistar rats were used in the present work. Animals were divided into two groups: normogonadic (NGN) and hypogonadic (HGN). These groups were also divided into four subgroups in accordance with the treatment: control with only water (C), fructose (F), oxonic acid (OA), and fructose + oxonic acid (FOA). Lipid profile, glycemia, uric acid, and creatinine determinations were assessed. Cardiovascular changes were evaluated by measuring blood pressure, myocyte volume, fibrosis, and intima-media aortic thickness.

RESULTS

HGN rats had higher levels of total cholesterol (TC) (p < 0.01) and noHDLc (p < 0.01), in addition to higher levels of uric acid (p < 0.05). The OA group significantly increased myocyte volume (p < 0.0001) and the percentage of fibrosis as well as the group receiving FOA (p < 0.001) in both gonadal conditions, being greater in the HGN group. Hypogonadic animals presented a worse lipid profile.

CONCLUSION

Mild hyperuricemia produces hypertension together with changes in the cardiac hypertrophy, fibrosis, and increased thickness of the intima media in hypogonadic rats fed high-fructose diet.

Relationship of Circulating Fetuin-A Levels with Body Size and Metabolic Phenotypes

BACKGROUND

Previous studies have suggested the existence of distinct body size subgroups according to metabolic health referred to as metabolically healthy obesity (MHO) and metabolically abnormal but normal weight (MANW) patients. Although nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity and metabolic syndrome, the relationship between these phenotypes and fetuin-A, a representative hepatokine, has not been explored.

METHODS

We examined the association between circulating fetuin-A levels, metabolic health phenotypes, cardiometabolic risk parameters, and subclinical atherosclerosis in 290 subjects who were randomly selected from an ongoing cohort study.

RESULTS

Fetuin-A concentrations were significantly associated with detrimental anthropometric and laboratory measurements, including increased waist circumference, blood pressure, alanine aminotransferase, fasting plasma glucose, and triglyceride levels. Furthermore, fetuin-A levels were significantly increased in the metabolically abnormal (MA) group compared to the metabolically healthy (MH) group in subjects without obesity (717.1 [632.1, 769.7] vs. 599.5 [502.0, 709.3], P = 0.001) and subjects with obesity (704.1 [595.5-880.9] vs. 612.2 [547.9-802.1], P = 0.016). In addition, brachial-ankle pulse wave velocity (baPWV), which reflects arterial stiffness, was higher in MA individuals compared to MH individuals. Multiple logistic regression analysis revealed that both individuals without obesity (P for trend = 0.017) and with obesity (P for trend = 0.028) in the higher tertiles of fetuin-A had an increased risk of MA than those in the lowest tertile.

CONCLUSIONS

This study demonstrates that fetuin-A levels are significantly associated with metabolic health phenotypes, such as MHO and MANW, in Korean adults.

Molecular mechanisms underlying metabolic syndrome: the expanding role of the adipocyte

The metabolic syndrome (MetS) is defined as a cluster of 3 or more metabolic and cardiovascular risk factors and represents a serious problem for public health. Altered function of adipose tissue has a significant impact on whole-body metabolism and represents a key driver for the development of these metabolic derangements, collectively referred as to MetS. In particular, increased visceral and ectopic fat deposition play a major role in the development of insulin resistance and MetS. A large body of evidence demonstrates that aging and MetS share several metabolic alterations. Of importance, molecular pathways that regulate lifespan affect key processes of adipose tissue physiology, and transgenic mouse models with adipose-specific alterations in these pathways show derangements of adipose tissue and other metabolic features of MetS, which highlights a causal link between dysfunctional adipose tissue and deleterious effects on whole-body homeostasis. This review analyzes adipose tissue-specific dysfunctions, including metabolic alterations that are related to aging, that have a significant impact on the development of MetS.-Armani, A., Berry, A., Cirulli, F., Caprio, M. Molecular mechanisms underlying metabolic syndrome: the expanding role of the adipocyte.

Insulin sensitivity and its relation to hormones in adolescent boys and girls

BACKGROUND AND AIMS

A subset of obese individuals lacks cardiometabolic impairment. We aimed to analyze hormonal profiles of insulin-sensitive obese (ISO) and insulin-resistant obese (IRO) adolescents and determine hormonal predictors of homeostasis model of insulin resistance (HOMA-IR).

MATERIALS AND METHODS

A threshold of 3.16 of HOMA-IR was used to classify ISO (<3.16) IRO (≥3.16). In 702 individuals aged 13-18years (55.8% girls) anthropometric and laboratory [blood glucose, insulin, thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), sex hormone-binding globulin (SHBG), steroid hormones, luteinizing hormone, follicle stimulating hormone, prolactin, ghrelin, glucose-dependent insulinotropic polypeptide, glucagon-like-peptide 1glucagon, leptin, resistin, visfatin, leptin, adiponectin and adipsin] assessments were performed. Orthogonal projections to latent structures and Mann-Whitney tests with Bonferroni correction were applied for statistical analysis.

RESULTS

52.6% girls and 42.9% boys were insulin sensitive. In the predictive model of HOMA-IR thyroid function tests, adiponectin, ghrelin and leptin concentrations played an important role in both genders. Prolactin, testosterone and glucagon contributed to the model only in boys, while progesterone and dehydroepiandrosterone sulfate levels only in girls. After Bonferroni correction levels of leptin, adiponectin, leptin/adiponectin ratio, SHBG and fT4/TSH ratio in both genders, testosterone and glucagon levels in boys and levels of TSH and fT3 in girls were related to insulin sensitivity.

CONCLUSION

Metabolic health defined by HOMA-IR is partly predicted by various hormones. Some of them are gender specific. Free T4/TSH and leptin/adiponectin ratios are related to insulin sensitivity in both genders.

The associations of leptin, adiponectin and resistin with incident atrial fibrillation in women

OBJECTIVES

Higher body mass index (BMI) is an important risk factor for atrial fibrillation (AF). The adipokines leptin, adiponectin and resistin are correlates of BMI, but their association with incident AF is not well known. We explored this relationship in a large cohort of postmenopausal women.

METHODS

We studied an ethnically diverse cohort of community-dwelling postmenopausal women aged 50-79 who were nationally recruited at 40 clinical centres as part of the Women's Health Initiative investigation. Participants underwent measurements of baseline serum leptin, adiponectin and resistin levels and were followed for incident AF. Adipokine levels were log transformed and normalised using inverse probability weighting. Cox proportional hazard regression models were used to estimate associations with adjustment for known AF risk factors.

RESULTS

Of the 4937 participants included, 892 developed AF over a follow-up of 11.1 years. Those with AF had higher mean leptin (14.9 pg/mL vs 13.9 pg/mL), adiponectin (26.3 ug/mL vs 24.5 ug/mL) and resistin (12.9 ng/mL vs 12.1 ng/mL) levels. After multivariable adjustment, neither log leptin nor log adiponectin levels were significantly associated with incident AF. However, log resistin levels remained significantly associated with incident AF (HR=1.57 per 1 log (ng/mL) increase, p=0.006). Additional adjustment for inflammatory cytokines only partially attenuated the association between resistin and incident AF (HR=1.43, p=0.06 adjusting for C-reactive protein (CRP); HR=1.39, p=0.08 adjusting for IL-6). Adjusting for resistin partially attenuated the association between BMI and incident AF (HR=1.14 per 5 kg/m(2), p=0.006 without resistin; HR=1.12, p=0.02 with resistin).

CONCLUSIONS

In women, elevated levels of serum resistin are significantly associated with higher rates of incident AF and partially mediate the association between BMI and AF. In the same population, leptin and adiponectin levels are not significantly associated with AF.

Obesity or obesities? Controversies on the association between body mass index and premature mortality

Obesity is still defined on the basis of body mass index (BMI) and BMI in itself is generally accepted as a strong predictor of overall early mortality. However, an inverse association between BMI and mortality has been reported in patients with many disease states and in several clinical settings: hemodialysis, cardiovascular diseases, hypertension, stroke, diabetes, chronic obstructive pulmonary disease, surgery, etc. This unexpected phenomenon is usually called obesity-survival paradox (OP). The contiguous concepts of metabolically healthy obesity (MHO, a phenotype having BMI ≥ 30 but not having any metabolic syndrome component and having a homeostasis model assessment of insulin resistance, HOMA, <2.5) and metabolically obese normal weight (MONW, normal-weight individuals displaying obesity-related phenotypic characteristics) have received a great deal of attention in recent years. The interactions that link MHO, MONW and OP with body composition, fat distribution, aging and cardiorespiratory fitness are other crucial areas of research. The article is an introductory narrative overview of the origin and current use of the concepts of MHO, MONW and OP. These phenomena are very controversial and appear as a consequence of the frail current diagnostic definition of obesity based only on BMI. A new commonly established characterization and classification of obesities based on a number of variables is needed urgently.

Predictors of leptin concentration and association with cardiovascular risk in patients with coronary artery disease: results from the AtheroGene study

CONTEXT

Leptin is produced in white adipose tissue, but also in human coronary atherosclerotic lesions.

OBJECTIVE

The aim of this study is to assess the prognostic value of leptin in patients with proven coronary artery disease (CAD) (N = 1907).

METHODS

AtheroGene is a contemporary CAD cohort study (N = 3229). Median follow-up time was 3.8 (Quartile 1/3 with 2.8/4.9) years.

RESULTS

Leptin concentration was associated with a hazard ratio (HR) for the fully adjusted model of HR = 1.32 in women but was not significant in men. The endpoint cardiovascular death and non-fatal myocardial infarction was observed in 167 patients.

CONCLUSION

In women with known CAD, increased leptin concentration is useful for predicting cardiovascular death and non-fatal myocardial infarction.

Metabolic Syndrome and Menopause: Pathophysiology, Clinical and Diagnostic Significance

Menopause is a risk factor for cardiometabolic diseases, including metabolic syndrome (MetS), type 2 diabetes, and cardiovascular diseases. MetS is a constellation of interdependent factors such as insulin resistance, abdominal obesity, dyslipidemia, and hypertension. The prevalence of MetS in postmenopause is due to loss of the protective role of estrogens and increased circulating androgens resulting in changes to body fat distribution and development of abdominal obesity. Excessive visceral adipose tissue plays an important role due to synthesis and secretion of bioactive substances such as adipocytokines, proinflammatory cytokines, reactive oxygen species, prothrombotic, and vasoconstrictor factors. MetS may also impact risk assessment of breast cancer, osteoporosis and chronic kidney disease, and quality of life during the menopausal transition. Increased MetS has stimulated the exploration of new laboratory tests for early detection and therapies.

Molecular insights into the role of white adipose tissue in metabolically unhealthy normal weight and metabolically healthy obese individuals

Obesity is a risk factor for the development of type 2 diabetes and cardiovascular disease. However, it is now recognized that a subset of individuals have reduced cardiometabolic risk despite being obese. Paradoxically, a subset of lean individuals is reported to have high risk for cardiometabolic complications. These distinct subgroups of individuals are referred to as metabolically unhealthy normal weight (MUNW) and metabolically healthy obese (MHO). Although the clinical relevance of these subgroups remains debated, evidence shows a critical role for white adipose tissue (WAT) function in the development of these phenotypes. The goal of this review is to provide an overview of our current state of knowledge regarding the molecular and metabolic characteristics of WAT associated with MUNW and MHO. In particular, we discuss the link between different WAT depots, immune cell infiltration, and adipokine production with MUNW and MHO. Furthermore, we also highlight recent molecular insights made with genomic technologies showing that processes such as oxidative phosphorylation, branched-chain amino acid catabolism, and fatty acid β-oxidation differ between these phenotypes. This review provides evidence that WAT function is closely linked with cardiometabolic risk independent of obesity and thus contributes to the development of MUNW and MHO.

Progression from metabolically benign to at-risk obesity in perimenopausal women: a longitudinal analysis of study of women across the nation (SWAN)

BACKGROUND

Little is known about the natural history of progression from a metabolically benign overweight/obese (MBO) to at-risk overweight/obese (ARO) phenotype. Improved understanding would help clinicians focus on controlling risk factors that predispose an obese individual to progression.

METHODS

Using discrete-time proportional hazard modeling on data from the Study of Women's Health Across the Nation (SWAN), we examined the incident progression from MBO (less than two metabolic syndrome abnormalities) to ARO (two or more metabolic syndrome abnormalities) and factors associated with progression over a 7-year period.

RESULTS

Of 866 MBO women at baseline, 43% progressed to the ARO phenotype. Compared with those who remained MBO, those who progressed had higher baseline BMI and a higher prevalence of cardiometabolic abnormalities (elevated glucose, triglycerides, blood pressure and low high-density lipoprotein cholesterol). In multivariable analyses, an increase in body mass index was associated with a modest increase in the risk of progression. Although all cardiometabolic abnormalities were associated with an increased risk, the baseline impaired fasting glucose showed the strongest association with the risk of progression [hazard ratio 3.24; 95% confidence interval 2.10, 4.92; P < .001]. Physical activity played a protective role in decreasing the risk of progression [hazard ratio 0.86; 95% confidence interval 0.80, 0.92; P < .001].

CONCLUSIONS

Increasing obesity and the presence of cardiometabolic abnormalities increase the risk of progression, whereas physical activity is the only lifestyle factor protective against progression from metabolically benign to the at-risk overweight/obese phenotype, a state that is unanimously associated with an elevated risk of cardiovascular morbidity and mortality.

Circulating leptin, resistin, adiponectin, visfatin, adipsin and ghrelin levels and insulin resistance in postmenopausal women with and without the metabolic syndrome

OBJECTIVE

To measure serum levels of adipsin, leptin, resistin, adiponectin, visfatin, ghrelin and insulin in postmenopausal women screened for the metabolic syndrome (METS).

METHODS

Serum of 100 postmenopausal women was analyzed using multiplex technology for the mentioned analytes. In addition, values for the homeostasis model assessment of insulin resistance (HOMA-IR) were calculated. Comparisons were performed in accordance to the presence or not of the METS and each of its components. Criteria of the American Heart Association were used to define the METS.

RESULTS

Age and time since menopause onset were similar in women with the METS (n=57) as compared to those without the syndrome (n=43). METS women displayed significantly higher levels of adipsin, leptin, resistin, insulin and HOMA-IR values and lower adiponectin levels. These differences were mainly observed among women with abdominal obesity, independent of fulfilling METS criteria or not. In this same sense, lower adiponectin levels significantly related to low HDL-C and high triglyceride levels; and higher insulin and HOMA-IR values related to high triglyceride and glucose levels, respectively.

CONCLUSION

In this sample, postmenopausal women with the METS displayed higher insulin and adipokine levels. These were mainly related to abdominal obesity and metabolic and lipid abnormalities. More research is warranted in this regard.

Ectopic fat and adipokines in metabolically benign overweight/obese women: the Kronos Early Estrogen Prevention Study

OBJECTIVE

It is unclear why despite a comparable cardiometabolic risk profile, "metabolically benign" overweight/obese individuals show an elevated risk of cardiovascular disease compared to normal weight individuals.

DESIGN AND METHODS

In cross-sectional analyses, we compared levels of ectopic fat (epicardial, pericardial, and hepatic fat) and adipokines (leptin, soluble leptin receptor, and high molecular weight [HMW] adiponectin) among metabolically benign (MBO) and at-risk overweight/obese (ARO), and metabolically benign normal weight (MBNW) women, screened for the Kronos Early Estrogen Prevention Study. We defined "metabolically benign" with ≤ 1, and "at-risk" with ≥2 components of the metabolic syndrome.

RESULTS

Compared to MBO women, ARO women had significantly elevated odds of being in the top tertile of epicardial fat (OR: 1.76, 95% CI: 1.04-2.99), hepatic fat (OR: 1.90, 95% CI:1.12-3.24) and leptin (OR: 2.15, 95% CI: 1.23-3.76), and the bottom tertile of HMW-adiponectin (OR: 2.90, 95% CI: 1.62-5.19). Compared to MBNW women, MBO women had significantly higher odds of being in the top tertile of epicardial fat (OR: 5.17, 95% CI: 3.22-8.29), pericardial fat (OR: 9.27, 95% CI: 5.52-15.56) and hepatic fat (OR: 2.72, 95% CI: 1.77-4.19) and the bottom tertile of HMW adiponectin levels (OR: 2.51, 95% CI: 1.60-3.94).

CONCLUSIONS

Levels of ectopic fat and the adverse adipokine profile increase on a continuum of BMI, suggesting that the metabolically benign phenotype may be a transient state.